June 14, 2022

2.5D Twin Screw Extruder Model Feed Section Analysis

Summary

The melting of polymers in a twin-screw (T/S) extruder is an important operation in many industrial processes. Research by Shih, Gogos, Geng and others has identified the physical phenomena that take place during the melting phase transition. This paper describes a new approach for modeling the melting in a twin-screw extruder and the model predictions are compared with an experimental study of Low Density Polyethylene (LDPE) melting in a co-rotating, intermeshing T/S extruder using on-line visualization and axial scanning of pressure and temperature techniques. This paper focuses on the physics and engineering concepts that are inherent in the melting mechanism in the extruder, and vis- cous energy dissipation in the melt with un-melted solids. The effects of throughput, Q, and at a constant rotation speed, N, is examined. Low and high Q/N ratios have significantly different axial pressure profiles.

About the Speaker

Greg Campbell was raised on the coast of Maine and was accepted as a student at the Orono campus of the University of Maine as a chemical engineering student in 1960. After his B.S he was the department's NASA fellow obtaining his M.S. and PhD. In 1968 he joined General Motors Research Laboratory as a research engineer and senior staff research engineers by 1978, the top of the technical ladder. Greg joined Mobil Chemical Research and Development in January 1982. He hired and managed 20 people, coordinating the design and construction of a 40,000 sq. ft. laboratory, and purchasing about 10 million dollars’ of equipment to equip the new facility. In 1984, Greg joined the Chemical Engineering faculty at Clarkson University. He has served as Chair of the Department1996-1998, Chief Information Officer1997-1998, and interim Dean of Engineering, 1998-2000, while maintaining his position as a professor in the Chemical Engineering department. At Clarkson he has the following accomplishments: 14 PhD Students, 19 MS Students, 22 Undergraduates Students: 3 visiting scientists/engineers who worked in laboratory, 67 Publication in refereed journals, 117 other publications, 12 patents, and 11 contribution to books. He also was the Director of the Extrusion and Mixing Consortium for 8 years. Greg has received several honors. In 2004 he was elected Fellow by the Society of Plastics Engineers. He is also an SPE Honored Service Member. He received the Research /Engineering Technology Award in 2015. In 2003 Greg was chosen to become the District Governor of Rotary District 7040. From 2001 until 2015 he served on the board of the Extrusion Division of the Society of Plastics Engineers. From 1991 to 1995 he was a Member of the Executive Committee of the International Polymer Processing Society. He has served on the SPE Executive committee and as SPE treasurer.

Fabrication of Expandable Filaments Towards In-Situ Foam 3D Printing of Microcellular Poly(Lactic Acid)

Summary

The purpose of this study was to investigate the feasibility of in-situ foaming in the fused filament fabrication (FFF) process. Development of unexpanded filaments loaded with thermally expandable microspheres, TEM is reported as a feedstock for in-situ foam printing. Four different material compositions, i.e., two grades of polylactic acid, PLA, and two plasticizers (polyethylene glycol, PEG, and triethyl citrate, TEC) were examined. PLA, TEM, and plasticizer were dry blended and fed into the extruder. The filaments were then extruded at the lowest possible barrel temperatures, collected by a filament winder, and used for the FFF printing process. The results showed that PLA Ingeo 4043D (MFR=6 g/10min) provides a more favorable temperature window for the suppression of TEM expansion during the extrusion process, compared to PLA Ingeo 3052D (MFR=14 g/10min). TEC plasticizer was also found to effectively lower the process temperatures without adversely interacting with the TEM particles. Consequently, unexpanded filaments of PLA, TEM and TEC were successfully fabricated with a density value of 1.16 g/cm3, which is only ~4.5% lower than the theoretical density value. The in-situ foaming in the FFF process was then successfully demonstrated. The printed foams revealed a uniform cellular structure, reproducible dimensions, as well as fewer print marks on the surface, compared to the solid counterparts.

About the Speaker

Karun Kalia is a Ph.D. student in the Plastics Engineering Department at the University of Massachusetts Lowell. The expected graduation date is Spring 2023. Research work includes material design, formulation, filament fabrication, 3D printing, and characterization of in‐situ printed microcellular structures as well as various other thermoplastic polymers and composites.

Elastollan® Thermoplastic Polyurethane

Summary

Recent innovation efforts at BASF have found a unique polyether-based thermoplastic polyurethane (TPU) that combines hydrolysis and microbial resistance with superior mechanical properties comparable to those expected from a polyester-based chemistry. Additionally, this TPU type has food-contact applications approval enabling many new application areas. One particularly valuable aspect is the outstanding burst pressure that this material can withstand, facilitating its use in pneumatic tubing.

About the Speaker

Felicia is a senior scientist in the Performance Materials division at BASF specializing in thermoplastic elastomers. She received her PhD in polymer science and engineering at the University of Massachusetts at Amherst and was a postdoctoral fellow at the National Institute of Standards and Technology before joining BASF in the greater Detroit area in 2014

Foaming Behavior and Property of PMMA Nanofoam Fabricated by Hot-Bath and Hot-Press Foaming

Summary

Nanocellular foam has attracted significant attention because of its superior physical and mechanical properties than microcellular foams. In this study, nanocellular foams were produced using the hot-bath and hot-press foaming methods. By lowering the saturation temperature (Tsat) to -30 °C, the CO2 solubility was increased to 45.6%, and the cell size was reduced to less than 40 nm. Samples prepared by hot-bath exhibited smaller cell size, thinner solid skin, and transitional layer.

About the Speaker

Dr. Shu-Kai Yeh is an Associate Professor at the Department of Materials Science and Engineering at the National Taiwan University of Science of Technology, Taipei, Taiwan. He is also the director of the Polymeric Foam Technology Alliance funded by the Ministry of Science and Technology, Taiwan. Prior to his current job, Dr. Yeh had been worked as an Assistant Professor and Associate Professor in the Department of Chemical Engineering and Biotechnology at the National Taipei University of Technology, Taiwan. Dr. Yeh obtained his B.S. degree in chemical engineering from National Taiwan University in 1999. He then came to the United States in 2001 and earned his Ph.D. from West Virginia University in 2007 under the supervision of Professor Rakesh K. Gupta. He has been working there with Professor L. James Lee at the Ohio State University since summer 2007 to Jan 2009. His major research interests include polymeric foam processing, polymer natural composites, polymer and composites rheology, and polymer recycling. Dr. Yeh has 47 publications since 2004. Among the 47 publications, 34 papers are related to polymeric foam.

Cyclic Olefin Copolymer Foam: A Promising Thermal Insulation Material

Summary

In the effort to alleviate climate change and energy consumption issues, thermally insulating polymeric foams can improve energy-management efficiency. we report a superior thermal insulation (~28.5 mWâ‹…m-1K-1) microcellular foam from ethylene-norbornene (NB) based cyclic olefin copolymers (COCs). Unlike the traditional carbon-filled approach, the incorporation of more NB segments (content from 33, 36, 51 and 58 mol %) in the COC structure greatly improved its ability to block thermal radiation without increasing its solid thermal conductivity. Using the supercritical CO2 and n-butane as physical blowing agents, we fabricated COC foams with tunable morphology. The void fraction of the foams ranged from 50 to 92%, and they demonstrated a high degree of closed cell content (>98%). In COC foams with given cellular structures (e.g. void fraction of 90%, cell size of 100–200 μm and cell density of ~107 cells/cc), their total thermal conductivity decreases from 49.6 to 37.9 mW…m-1K-1 with increasing NB content from 33 to 58%, which is attributed to high- NB COC’s strong ability to attenuate thermal radiation.

About the Speaker

Sundong Kim is a fourth-year Ph.D. candidate in Multifunctional Composite Manufacturing Laboratory in the Department of Mechanical & Industrial Engineering at University of Toronto. He completed his B.A.Sc. in Mechanical Engineering at the Ajou University, South Korea in 2015, and my M.A.Sc. in Mechanical Engineering at University of Vermont, USA in 2017. His research focus is on self-reinforced composite foaming. Other topics of interest include extrusion/batch/injection foaming, machining, and nanolayers.

ABS/Carbon Fiber Composite Foams With Bimodal Fine-Cell Structure Prepared Using Supercritical C0₂

Summary

Via two-step solid-state foaming using subcritical CO2 as blowing agent, the foamed acrylonitrile-butadiene-styrene/carbon fibers (ABS/CFs) composites are prepared. The results demonstrate that a bimodal cell structure (BMCS) is developed in the foamed ABS/CFs composites. Small and denser cells are developed in the ABS matrix, whereas large cells are formed around the CFs due to concentrated CO2 at the ABS CFs interfaces interfaces. The mean cell diameters are 0.39-0.92 μm for the small cells and 12.5-25.6 ¼m for the large cells, being dependent on the CFs content. The CFs especially at 10 wt% or higher can refine the small cells via both increasing the strength and elasticity of the ABS matrix and restricting their growth under large cell growth. Interestingly, slow depressurization for the saturated composites followed by foaming is also favorable to refine the small cells, which is mainly attributed to no cells to be preformed in the saturated composite via the slow depressurization. Relatively higher saturation pressure or modest foaming temperature can further refine the BMCS in the foamed ABS/CFs composites.

About the Speaker

Dr. Huang is the professor and academic leader of polymer processing and machinery at South China University of Technology (SCUT). He received his BS degree in polymer processing and machinery from SCUT in 1984, and Ph. D in polymer processing engineering from the same university in 1995. His research interest includes micro molding, polymer foaming, polymer processing rheology, and fluid assisted polymer processing. He has more than 280 journal publications, 38 patents, one book on blow molding and 7 book chapters.

Experimental Studies of High Density Polyethylene Exposed to Chlorine Dioxide Media With Various Concentrations and Temperatures

Summary

High density polyethylene (HDPE) is one of the most widely used materials in the pipe industry because of its several advantages such as low price, excellent productivity, light weight and high resistance to chemical degradation. For potable water pipes, their lifespans are supposed to be over 50 years, so it is essential to check their long-term performance in certain service conditions. The point is that potable water contains disinfectants including chlorine or chlorine dioxide which shortens the service time of water pipes. In addition to disinfectant, environmental conditions like internal pressure and temperature of media inside also cause deterioration of properties of plastic pipes. To understand the degradation mechanism by potable water, we focused on two parameters, the concentration of disinfectant and the temperature of the solution. In this study, specimens obtained from HDPE pipes were artificially degraded in 5 different kinds of chlorine dioxide solutions with various concentrations and temperatures. Micro-tensile tests were conducted to study the variation of mechanical properties of HDPE specimens. The fourier transform infrared (FTIR) spectrometry and the gel permeation chromatography (GPC) analysis were also conducted to study the variation of chemical properties of HDPE according to exposure time to chlorine dioxide solutions.

About the Speaker

Min-Seok Choi received his B.S. degree in Mechanical Engineering from Korea University in 2016. He is currently a candidate in the Combined Master's and Doctorate program in the School of Mechanical Engineering at Korea University. His research interests include nanocomposite, fracture mechanics and environmental degradation mechanism of engineering plastic.

Recycling of PA66/Silicone-Wastes

Summary

Multi-layer materials (e.g. in packaging or technical parts) are used to achieve certain properties of products. However, a major challenge of plastics recycling is the separation of the various polymer components. One example for this are airbags. Airbags consist primarily of polyamide 6.6 fibers and an additional silicone coating. During recycling, the silicone layer cannot be mechanically separated from the synthetic fiber. Therefore, the silicone particles remain in the recyclate with a poor bonding to the PA66 matrix. In turn, this can lead to poor mechanical properties of the recycled material and early material failure due to interface detachment. In this work, a new recycling strategy for the functional integration of silicone particles is demonstrated using the example of airbag waste. A reactive compounding of the wastes with a silane-coupling agent in a twin-screw extruder was conducted and led to a strong coupling between the silicone particles and the PA66 matrix. Rheological tests confirmed the formation of a cross-linked structure by adding the coupling agent. Nano-IR-AFM analyses demonstrated the improved integration of the silicone particles into the PA66 and the reduction of cavities in the compound. Mechanical tests showed the increase in notched impact strength and elongation at break and therefore the possible function of the silicone as an impact modifier. However, a further analysis of the process in a hinged twin-screw extruder emphasized the need for an adjustment of the machine parameters as well as the screw concept in order to optimize the reaction conditions in the processing zone and to prevent post-reactions and degradation effects.

About the Speaker

Studies: Material Sciences (M.Sc.), University of Göttingen, Germany Career: since 2017, scientist at the Institut für Kunststofftechnik (IKT), University of Stuttgart (Germany) Field of research: material engineering, (reactive) compounding, polyamides

Thermal Degradation Mechanism of Polylactic Acid

Summary

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About the Speaker

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Development of a Non-Destructive Measurement Method for Quality Assessment of Foamed Plastic Parts

Summary

Foamed parts are being produced in ever greater quantities. This is done, on the one hand, to save weight and, on the other hand, to take advantage of the greater design freedom in the layout of foamed components. Until now, quality control of the foam structure has hardly been possible without destructive testing methods. Therefore, a test method is presented to qualitatively evaluate the foam structure of foamed components without destruction.

About the Speaker

TBA

Colloidal Stability and Gel Prevention of Urethane-Acrylate Interpenetrating Polymer Network Systems

Summary

Advances in nanotechnology and surface sciences have necessitated superior polymeric coatings with novel applications. Urethane-acrylate-based interpenetrating polymer networks are one such class of ultra-tough polymers being researched actively for their wide-ranging applications from bullet-proof vests to binders for super de-wetting coatings. Urethane-based systems are well-known for undergoing side reactions which could result in instability of colloidal suspensions engendering gelation resulting in significantly reduced shelf life of synthesized formulations and coating inconsistencies over time. Consequently, it becomes crucial to examine and control the factors inducing gelation. In this study, we investigate two approaches to prevent the gelation of colloidal urethane-based suspensions. In the first approach, we tune the NCO:OH ratio, and in the second approach, urea groups were formed in the presence of water. It was observed that both approaches resulted in storage stable colloidal suspensions with more than six months of shelf life. Durability assessment of coatings however indicated that urea-containing formulation resulted in notably robust coatings as compared to NCO:OH tuned coatings which can be attributed to the presence of strong hydrogen bonding arising from bifurcated hydrogens of urea.

About the Speaker

Puneet Garg is a final year PhD student at the Research School of Chemistry and Research School of Engineering at Australian National University, where he is a part of the Nanotechnology Research Laboratory, Laboratory of Advanced Biomaterials and Australian Research Council Training Centre for Automated Manufacture of Advanced Composites. Puneet received his bachelor and master engineering degrees in Biomedical and Nanotechnology from India. His research focuses on enhancement of novel polymer materials for the design of next-gen coatings with application in De-Wetting and Easy-Cleaning.

Ultraviolet-C (UVC) Exposure and Its Effect on Color Change for Polystyrene (Part 1)

Summary

Due to the recent and ongoing pandemic – COVID-19 – there was an urgency to determine a method to delay the continuously rapid development of the new virus. As a result, Ultraviolet-C (UVC) light, also known as Ultraviolet Germicidal Irradiation (UVGI), has been in higher demand because of its known ability to disinfect quickly and effectively. However, because of its short wavelength/higher energy, either 222nm or 254nm, material degradation is usually much more accelerated than Ultraviolet-A (UVA) or Ultraviolet-B (UVB). At this moment, this study only observed color change when exposing polystyrene to UVC light, and it is believed that this is one of the first studies, if not the first, conducted with this material. Polystyrene was selected because of its availability, abundance of relevant research (ie. UVA/UVB exposure results), and its use in weathering standards. Additionally, since there are no standards specifically about UVC exposure, this preliminary research may provide some direction.

About the Speaker

Kristen Chang is currently the R&D Engineer at Atlas Material Testing Technology LLC and has been with Atlas since November 2019. Her current role has mostly been analyzing material degradation with UV exposure, as well as supporting her previous role as the Optical Engineer. She received a Bachelor's of Science in Engineering with a Chemical Concentration from Calvin College.

Analytical Method Development for Additive Analysis in Polyethylene

Summary

The overall goal of the project targets the development of a product containing a rheology modifier additive in polyethylene (PE). This product is being sold to film converters for addition to the extruders of blown-film lines together with LLDPE resins. This increases the melt-strength during processing and the shrink tension for collation shrink films, enabling reduction in LDPE content and resultant tougher films. A tougher film will allow down-gauging and hence reduce material consumption, increasing the sustainability component for customers. This study focuses on the development of an analytical method at Dow to measure the concentration of the rheology modifier additive in PE. The method was validated and implemented successfully.

About the Speaker

Praveen Boopalachandran is currently a Research Scientist for Core R&D at the Dow Chemical Company. His expertise is in the area of optical spectroscopy and process analysis. Praveen serves as a R&D focal point for Dow polyurethane business to provide analytical solutions for new product development and existing product offerings. Praveen also serves as a global technology network leader for optical spectroscopy. Praveen is a certified Six Sigma Green Belt project leader. Other leadership roles include integration coach for new hires, interview team and technical mentor in analytical sciences. Before joining Dow, he was a Postdoctoral research associate at the University of Minnesota. He received his Ph.D. from Texas A&M University under the guidance of Jaan Laane.

Density-Based Analysis of Polymers Using Magnetic Levitation Device Constructed by Magnet Arrays

Summary

Due to rising demands on the quality of the final plastic product, it becomes increasingly important to influence the thermal behavior of the injection molding tools. Due to this fact the geometry of heat control channels becomes very complex, leading to a change in the manufacturing strategy of large-scale tools: manufacturing of a layered structure followed by joining the complete component. Besides the influence of the surface roughness and precision of the mold making the possibility of joining non-planar surfaces is elucidated. To demonstrate and to evaluate the diffusion bonding process, a demonstrator injection-molding tool was constructed and realized by joining the nozzle side and the ejector site of the mold by diffusion bonding after the contour conformal cooling channels were integrated. The cycle time for the production of fan wheels with the finalized mold could be reduced by 10%. Moreover, the concentricity of the fan wheels could be improved.

About the Speaker

TBA

Density-Based Analysis of Polymers Using Magnetic Levitation Device Constructed by Magnet Arrays

Summary

This paper proposed a novel MagLev device using magnet arrays, which can accommodate large-scale samples. Unlike magnet arrays in previous studies, all magnets employed herein face the same direction. The magnetic field generated by the magnet arrays is similar to that of the standard magnet. Within the magnetic field induced by the magnet arrays, the polymer can be levitated to an equilibrium position in a paramagnetic solution and the levitation height is related to its density. The equation correlating density and levitation height can be obtained according to the simulation results. Solutions of different concentrations were used to measure densities of a variety of polymers with an accuracy of ±0.0003 g/cm3. The non-destructive testing could also be used for plastic parts based on its posture (orientation) within the paramagnetic solution. The use of magnet arrays circumvents the trouble of manufacturing large magnets, realizes testing of polymers/parts with large sizes, and facilitates industrialization of magnetic levitation detection.

About the Speaker

Peng Zhao is the professor and deputy dean of School of Mechanical Engineering in Zhejiang University. He is the vice director of Plastics Mould Committee in China Die & Mold Industry Association. His research focuses on polymer injection molding technology and equipment.

An Integrated Three Dimensional Numerical Simulation of Nonlinear Warpage Analysis

Summary

The paper describes the development of a variotherm process which increases the mold surface temperature during the injection molding process without significantly extending the cycle time and minimizes unintentionally heated mold areas. To this end, the possibility of achieving the desired effects by direct introduction of heated gases into the mold cavity is being investigated. By addressing central issues such as gas distribution geometry, injection possibilities, required gas temperatures or the possibility of process implementation in a demonstrator mold, it was possible to develop a process with which it is possible to achieve temperature optimization for visually appealing parts within seconds. This means that weld lines, streaks or uneven mold impressions can be concealed even on flat parts.

About the Speaker

TBA

An Integrated Three Dimensional Numerical Simulation of Nonlinear Warpage Analysis

Summary

Nonlinear warpage has attracted more and more attention recently, especially in the automotive industry. This study is mainly aimed at the possibility of buckling and large deformation in the warpage stage of large and thin polymer products during mold release. We have established a set of FEM analysis models dealing with the geometrically nonlinear deformation in Moldex3D software. Cooperate with the temperature distribution and the residual stress caused by the phase change obtained in the plastic processing and manufacturing process by numerical simulation and accurately predict the large deformation of the product due to the design layout or processing and manufacturing processes.

About the Speaker

Hsiang Liang is now a Research and Development engineer at Moldex3D. He focuses on developing the nonlinear solid mechanics solver to deal with the warpage and stress analysis and is familiar with numerical methods to solve different industrial problems. He received his master’s degree at National Taiwan University in 2018.

Deformation Analysis of Mold Cavity with SLA Conformal Cooling Channel Insert

Summary

Injection molding is the process of injection molten plastic into a mold to form desired shape of part and it’s widely used process for mass production of plastics over the world. This process is not complete without the mold as it is the most critical part of the process. The cost of producing mold is huge due to manufacturing process and technique, tool material and cost of labor. The more effective the mold, the more efficient the process and the more profitable to the business. A critical factor is the cooling time, and a well-designed mold can achieve even cooling in the shortest period, which leads to increased productivity and higher quality of molded parts. In this research, an alternative core design was employed, to achieve these goals during the molding process. The core has 2 parts: the core and core insert. The core insert was produced using SLA technology to achieve the conformal cooling while the core was machined, and the deflection was studied using finite element analysis.

About the Speaker

TBA

Monitoring of Injection Molding Process with Piezo-electric Sensor

Summary

Injection molding is one of the most popular techniques for global plastic production. With this automation technique, the plastic products can be manufactured at low cost with a complex geometrical shape. A manufacturing process with high productivity of an injection molding machine depends on optimized injection molding parameters. Injection molding pressure and temperature inside the mold cavity are the most critical parameters. However, cavity pressure transfer is not used due to cost and maintenance issues. During this research, an experimental procedure is performed to determine a process monitoring system using asynchronous data acquisition, through the incorporation of a wired piezo-ceramic sensor to acquire pressure of the injection molding system. This piezoelectric sensor is designed in such a way that, a Bluetooth device can be connected with a sensor and can take live data reading of parameters from the running molding machine.

About the Speaker

TBA

Quality Prediction in Injection Molding Based on Thermal Images With Convolutional Neural Networks

Summary

Precise predictive models are required in order to use machine learning methods for quality control in injection molding. Thermal images offer the advantage of having information in the data that is not available in machine and process data. Currently, convolutional neural networks (CNN) have many applications in image recognition. Therefore, the objective of this work was to investigate the application of convolutional neural networks to thermal images of injection molded parts. For this purpose, 751 injection molding cycles from a central composite design were used. The goal was to predict the weight, height, and width of the injection molded part. The results were also compared with classical machine learning methods. Depending on the quality parameters, the networks were able to achieve an R² of up to 0.91 and were thus among the three best methods.

About the Speaker

2013-2017: Bachelor of Science in Industrial Engineering at the University of Duisburg-Essen. 2017-2019: Master of Science in Industrial Engineering at the University of Duisburg-Essen. Since 2019: Research associate/Ph. D. student at the Institute for Product Engineering at the University of Duisburg-Essen. Main research focus: Process optimization and digitalization in injection molding.

Study on Machine Identification and its Effect on the RSM Optimization in Injection Molding

Summary

Different optimization methods or strategies have been proposed and utilized to enhance the quality of injected products for many years. However, what is the machine characteristics to influence the efficiency of the optimization method? It is not so clear yet. In this study, the injection machine characteristics has been identified using numerical simulation (Moldex3D) based on a round plate system. The response surface method (RSM) has been further utilized for both simulation prediction and experimental conduction to discuss the efficiency of the optimization for operation parameters in injection molding. Results showed that before the machine identification and calibration, the quality of injected part can be improved by 75% theoretically, but the real experimental one demonstrated worse result. However, the difference between simulation and experiment is the same no matter the system has been through RSM optimized or not. Moreover, after the machine has been identified and calibrated, the difference between simulation prediction and experimental observation has been improved by 71.4%. Also, the accuracy of the RSM optimization in the real experiment has been enhanced by 50% (from -0.06 mm to 0.03 mm). Obviously, it demonstrated that the machine identification for the real capability is very important.

About the Speaker

Dr. Chao-Tsai Huang is currently an Associate Professor at Department of Chemical and Materials Engineering, Tamkang University in Taiwan. Before he moved to University, he has been worked at CoreTech System (Moldex3D) Co., Ltd for over twelve years. Recently, he is working on lightweight technology using fiber-reinforced plastics (FRP), and the mechanism to cause the deviation between simulation and experiments. He is also studying on some special molding technologies, including multi-component molding (such as overmolding, co-injection, bi-injection), simulation and validation on fiber microstructure of the polymer composites in injection molding or in compression molding, chemical and physical microcellular foaming, polymer material property characterization development. CT received his Bachelor's degree in Chemical Engineering from Taipei Institute of Technology, and his Master of Science and Doctor of Science in Chemical Engineering from Washington University in St. Louis.

Discover Physical Mechanism of Interface Formation in Co-injection Using Rheological Behavior

Summary

Co-injection molding has been introduced into industrial application for several decades. However, due to the formation of the interface between skin and core materials is very difficult to observe, and to control, a good quality of co-injection product can not be obtained effectively. Moreover, the interfacial morphology between skin and core materials of the co-injection molding is very sensitive to various factors. Especially, the physical mechanism to form that morphology is not understood comprehensively yet. In this study, the formation of the interfacial morphology and its physical mechanism in co-injection molding have been studied based on the ASTM D638 TYPE V tensile bar system by using both numerical simulation and experimental observation. Results showed that the critical skin/core material ratio to initiate skin break-through is identified. The reason to cause the break-through is due to the flow front of core material catches up with the melt front of skin, and the skin is stop at a fixed distance. This mechanism is similar with that of Watanabe et al [6]. However, when the higher core material ratio is selected, the mechanism of the interfacial morphology is different. Specifically, after core melt front catches the skin melt front, the broken skin material can move forward with the inner core material to generate special core-skin-core structure. It could be due to different forces balance inside the skin and core melts, but needs to do more study in the future.

About the Speaker

Dr. Chao-Tsai Huang is currently an Associate Professor at Department of Chemical and Materials Engineering, Tamkang University in Taiwan. Before he moved to University, he has been worked at CoreTech System (Moldex3D) Co., Ltd for over twelve years. Recently, he is working on lightweight technology using fiber-reinforced plastics (FRP), and the mechanism to cause the deviation between simulation and experiments. He is also studying on some special molding technologies, including multi-component molding (such as overmolding, co-injection, bi-injection), simulation and validation on fiber microstructure of the polymer composites in injection molding or in compression molding, chemical and physical microcellular foaming, polymer material property characterization development. CT received his Bachelor's degree in Chemical Engineering from Taipei Institute of Technology, and his Master of Science and Doctor of Science in Chemical Engineering from Washington University in St. Louis.

The Development of a Flexible Spout for Flexible Packaging

Summary

Flexible packaging has seen significantly rapid growth in recent years because of its many advantages, such as light-weight and compact design as well as high sustainability. In this paper, the development of a novel flexible spout (fitment) for flexible pouch applications is presented. This flexible spout has a cylindrical base, and thus can be manufactured more efficiently, consistently, and cost-effectively than rigid spouts with winglets. Since it is made of flexible materials such as INFUSE Olefin Block Copolymer and Polyethylene blends, it provides comfort for the end user and improves user experience. The key to the successful production of hermitic flexible pouches with this flexible spout is to form winglets in-situ during the heat sealing process. Both finite element (FE) modeling and experimental techniques were used extensively through this work, which demonstrates that the effective utilization of these tools combined with engineering judgment can efficiently solve complex and challenging real-world problems, and significantly accelerate the new product development process.

About the Speaker

Liangkai Ma is a research scientist specializing in new mechanical modeling capabilities and test methods development. During his 11 years working experience with Dow, he has led many projects that resulted in innovative solutions to customers across different market segments including light weighting, flexible packaging, renewable energy, and transportation. Liangkai holds a Ph.D. in Mechanical Engineering from Michigan State University. He currently has 8 granted patents and has published 27 journal and conference technical papers. He has been a member of SPE, ASC, SAMPE, and NAFEMS.

A Recycle Stream in the Reactive Extrusion Process for Preparing Lignocellulosic Thermoplastic

Summary

Processes needing to extrude biopolymers can be challenged by the poor flow properties often exhibited by this class of materials. Lignocellulose is one such material that is very attractive to the future polymer industry as a potential engineered biopolymer suitable for structural applications. To convert the poorly processible lignocellulose pulp into a flowable thermoplastic, the chemistry of both cellulose and lignin need to be modified, and to do so economically, attention is turned towards reactive extrusion. A reactive solution is required for the modification but also, to simply allow the lignocellulose to flow through the extruder. This study examines the novel idea of a recycle stream in reactive extrusion to reduce the normally high concentration of reactive solution needed. The goal behind the recycle stream was to produce an exiting product requiring minimal recovery of the unreacted solution without the introduction of a contaminant into the process to aid lignocellulose flow. The results showed that a comparable thermoplastic product could be produced with ~50% less reactive solution by recycling 25% of the exit stream back into the process, The recycled polymer was an effective plasticizer for the lignocellulose pulp, lowering the reliance on the reactive solution to offer this function in addition to acting as the modifier.

About the Speaker

Dr. Michael Thompson is a Professor of Chemical Engineering and Associate Dean of Engineering at McMaster University in Canada. His research looks at processes related to polymers or particulate production, to develop new manufacturing solutions for the industries of polymer, food, pharmaceutical, and energy. Much of his work over the past decade has focused on unique processing technologies with extruders. He has over 100 publications in these areas of processing.

Multilayer Extrusion of Higher and Lower Modulus Alternating Polymer System

Summary

Multi-Layer extrusion (MLE) is an advanced co-extrusion processing technology, which enables two polymer systems to be melt extruded, combined in an alternating format to very small total thickness <100µm and arranged in higher number of layer typically ranging from 8 to 1024. The focus of this paper is to investigate polymeric materials which are higher modulus (e.g. LNP EXL PC copolymer or polymethyl methacrylate PMMA) and relatively lower modulus (TPU) in nature as an alternating material combination for MLE. By combining different modulus of polymeric materials in MLE films, it is possible to achieve desired balance of properties (mechanical, thermal, optical, dielectric etc.) by synergistically combining the properties of the individual resins. In this paper flexural test is shown as an example to discuss the performance of MLE films. One of the major challenges of the MLE process is the down-selection of materials that are thermoplastics and have "matching" viscoelasticity at the processing temperature, as assessed by viscosity measurement at lower shear rates. Additionally, in order to ensure inter-layer adhesion, solubility parameters and processing windows of the two resins must be considered. In this study differences in adhesion were noted between PC⁄PU and PMMA⁄TPU MLE system. In PMMA/TPU MLE modification of processing temperature resulted in improved interfacial stability and interlayer adhesion.

About the Speaker

More than 9 years of industrial experience as a material scientist and project manager Dr. Thambi who is working currently at SABIC focus on the development of polymers in different market segments such as Automotive, Consumer Electronics, Infrastructure, etc. In his current role, Dr. Thambi identify, investigate potential business oppurtunity and develop high-performance polymer and composite applications. He has 10 year of technical working experience in Europe and now he is working as Senior Scientist at SABIC Bangalore, India. Dr. Thambi hold a Ph.D. degree from well-renowned Germany's Technische University of Berlin, in the field of material science and modeling and a masters degree in Automotive engineering at Fachhochschule Ingolstadt, Germany. His bachelor degree is in Mechanical engineering from Anna University, Chennai, India. His field of research is in co-extruded very-thin films , long term performance of polymers, SMT reflow materials and radar absorbing polymers. He has multiple patents published and peer reviewed papers in these fields.

The Toughening of Highly Crosslinked Epoxy Networks using Core-Shell Rubber Particles

Summary

This work explores the effect of core shell rubber (CSR) addition on the resulting properties of a highly crosslinked bi-component epoxy resin blend. The effects of network structure and topology are explored and related to the efficacy of CSR as a toughener for rigid, high-Tg polymer networks. A combination of thermal, spectral, and mechanical testing shows that excellent toughness enhancement can indeed still be achieved, despite a modest reduction in flexural properties for a high glass transition temperature (~259°C) network.

About the Speaker

Samuel Swan has had a short but diverse career in the polymer composites field. Finishing his Bachelors in Mechanical engineering at the University of Portland, Samuel developed and characterized novel automation of the resin infusion process for 50m yachts and investigated the tool life of arc-plasma coated drills in the one-step drilling of carbon fibre/titanium structures. After completing his Masters by research from Washington State University, Samuel worked for a well-known aerospace and defense composites manufacturer before travelling to Australia to take up a PhD in composite materials related work. Samuel has since learned extensively about high temperature resins with a focus on multi-functional epoxies. Newer works include defect and quality in pultruded carbon fibre beams, recycling of carbon fibre into long-fibre preforms, and development of new bio-derived polymers and binders for manufacturing hybrid composites from recycled fibre.

Scratch & Fracture Behavior of Talc-Reinforced Polypropylene

Summary

Thermoplastic polyolefins (TPOs) have been widely utilized in a variety of automotive applications. Most importantly, the TPOs used in interior and exterior parts in automotive applications require aesthetics and good mechanical properties simultaneously. Among many of the inorganic fillers, talc is an inexpensive and natural mineral, which has the platelet structure with individual layers holding together by week Vander Waals forces. This distinct layer structure can be delaminated at low shear forces to easily disperse in TPOs. Additionally, the talc particle size can be manipulated by the various micronizing processes. In this research, talc-reinforced polypropylene (PP) systems as a set of model systems have been chosen to investigate how the particle size and surface treatment of talc influence the TPO fundamental scratch and fracture behaviors.

About the Speaker

Kwanghae Noh is a Ph.D. student in Department of Materials Science & Engineering at Texas A&M University, College Station. He received bachelor degree in Chemical Engineering from Hanyang University, South Korea, in 2015. Currently, he is researching for structure-processing-property relationship for fracture and tribological behavior of polymeric materials in Polymer Technology Center under the supervision of Prof. Hung-Jue Sue.

FEM Modeling on Scratch Behavior of Micro-Patterned Polymer Surfaces

Summary

Polymers are inherently scratch sensitive due to their soft nature. Utilizing patterned surfaces while retaining transparency is a viable strategy to achieve better scratch performance. In this paper, we model the scratch behavior of micro-patterned surfaces using FEM simulation by employing a powerful coupled Eulerian-Lagrangian approach. The effect of two different pattern types on scratch behavior is studied and validated with available experimental results. Results suggest the significance of patterned surface topology in improving scratch performance.

About the Speaker

Sumit Khatri did his BS in Aerospace Engineering at IIT Kharagpur, India in 2015. He worked as a Research Associate in the Dept. of Aerospace Engineering, IISc Bangalore from 2015-2017. In 2017, He joined the Dept. of Aerospace Engineering in Tamu and completed my MS by 2019. He is currently a Ph.D. student in the Dept. of Materials Science & Engineering at Texas A&M University. He does research in the mechanics & materials domain. He is presently working on scratch damage modeling in polymers using Abaqus and concurrent experimental validation.

Extraction of Cure-Dependent Fatigue Behavior of Filament-Wound Composites for Fuel Cell Vehicle App

Summary

The extraction of cure-dependent fatigue behavior under tension-tension fatigue is presented for filament-wound coupons. Displacement controlled fatigue tests are performed on tubular filament-wound coupons. The state of the tube is characterized by performing interrupted static tests in between the fatigue cycles. At the coupon level, the state of damage in the matrix is obtained using micromechanics expressions with the help of Digital Image Correlation (DIC) technique. The results show a noticeable difference between 95% (fully cured) and 80% cured composite specimens.

About the Speaker

Assistant Research Scientist - Aerospace Engineering department, University of Michigan. PhD in Aerospace Engineering, University of Michigan (2014) Areas of interest: Composite materials, cellular solids, cure modeling in composite materials, buckling of thin walled structures.

Experiment and Simulation of 1D Flow and In-plane Permeability Validation in RTM

Summary

The material properties of fiber reinforced plastics are highly directional and the final fiber orientation can usually only be determined after the manufacturing process by time-consuming and cost-intensive sample preparation. The determination of the mechanical properties usually requires destructive testing. Compared to conventional methods, the method of ultrasonic birefringence presented here allows a non-destructive determination of the shear moduli G13 and G23. Furthermore, it allows the determination of the fiber orientation without the need of a complex specimen preparation. The difference in shear modulus measurement between the two methods is less than 1 %.

About the Speaker

Yu-Ho is an engineer with 2 years experience in the Material Research Center at Moldex3D. She has experience in polymer science and engineering. Her experience and key skills include the following:

• Polymer basic knowledge
• Polymer materials research (PBSL composite, VAE emulsion, ABS)
• Polymer processing research (RTM)
• Software skills: Moldex3D software, Rhinoceros, C++ programming language

Evaluation of Shear Modulus Using Destructive Shear Test and Non-destructive Ultrasonic Shear Waves

Summary

The material properties of fiber reinforced plastics are highly directional and the final fiber orientation can usually only be determined after the manufacturing process by time-consuming and cost-intensive sample preparation. The determination of the mechanical properties usually requires destructive testing. Compared to conventional methods, the method of ultrasonic birefringence presented here allows a non-destructive determination of the shear moduli G13 and G23. Furthermore, it allows the determination of the fiber orientation without the need of a complex specimen preparation. The difference in shear modulus measurement between the two methods is less than 1 %.

About the Speaker

— Research Associate at Institut für Kunststofftechnik (Institute of Plastic Engineering); since 2017 — Master of Science in Aerospace Engineering

Preliminary Investigation of Oxygen Pressurized Chambers for Accelerated UV Weathering

Summary

This paper presents results of a preliminary proof-of-concept investigation into the effect of pressurized oxygen on UV photodegradation rates of a polystyrene standard reference material. Exposures under UVA and UVB revealed significant and important acceleration effects using pressurized oxygen compared with ambient air.

About the Speaker

A graduate of The University of Arizona, Kelly has been working since 1983 in service life prediction, environmental simulation, and weathering materials degradation on an R&D, Engineering and Quality Assurance level. Kelly has worked as a Researcher, Quality Process Engineer, and Engineering Manager for Alcoa Building Products and Dayton Technologies. Kelly is a Certified Quality Engineer as well as an ISO lead Assessor. Currently, Kelly performs research, develops new products, and manages intellectual assets for Atlas Material Testing Technology an Ametek company. Kelly recently taught statistical methods at community college, holds seven patents, and represents Atlas’ technical research abilities at symposia, with consortia and in published literature. Kelly’s efforts led to an R&D100 award for Atlas in partnership with The National Renewable Energy Laboratory and the Institute for Laser Optical Technology.

An Explicit Non-Newtonian Fluid Model for Polymeric Flow With Finite Stretch

Summary

After nearly 80 years of research in constitutive modeling of polymeric fluids, simple yet capable models are still sought after today. In this work, we provide an explicit constitutive equation where the extra stress tensor is an explicit function of the objective velocity gradient while finite stretch of polymer chains are considered. With this model, the basic rheological functions in uniaxial extensional, planar extension and simple shear can all be obtained as closed-form analytical solutions with only elementary mathematical functions involved. The new model demonstrates excellent fitting to some sear and extensional data in the literature, and is able to simultaneously predict the major rheological functions in steady-state shear and extension.

About the Speaker

Donggang Yao (email: yao@gatech.edu; phone: 404-894-9076), Professor in School of Materials Sci. & Eng. at Georgia Institute of Technology, received a BS degree in Precision Instruments from Shanghai Jiao Tong University, China in 1991 and MS and Ph.D. degrees in Mechanical Engineering from University of Massachusetts Amherst in 1998 and 2001. He teaches and directs research in the broad area of polymer engineering. His ongoing research deals with sustainable polymer/composites processing, precision molding, high-strength fiber processing, constitutive modeling, and process modeling.

A Semi-Genetic Process for Fitting Polymer Viscosities and Selecting Best Models

Summary

This paper presents a process for fitting corrected viscosity data to constituent and temperature dependent data to a range of two-equation models. The process tests different models to determine the best fit model for each. Rheometer data for polymer melts, after corrections for shear rate and entrance pressure losses, may fit one model better than another, and as such the following constituent models are reviewed in the form as they are commonly applied in commercial software today: 1) Cross Model, 2) Modified Cross Model, and 3) Carreau-Yasuda. Once the constituent model is fit, the following temperature dependent models are compared: 1) WLF, Exponential, Arrhenius, and Masuko-Magill. The differences between the models are presented in order to highlight the need to compare different models to obtain a best fit. Lastly, a solution is presented to the problem of convergent viscosities with respect to shear rate as compared across a range of temperatures as no existing model in common use today can capture this specific behavior.

About the Speaker

Senior Applications Engineer on the Global Technical Support Team at Altair Engineering, I graduated from Culver Military Academy in 1987, then Aquinas College in December 1992 with a BA in Philosophy, then an AAS from Grand Rapids Community College in Plastics Engineering in May 1996 , and then a BS in Plastics Engineering Technology from Ferris State University. After graduation, and getting into simulation, I took Calculus 3, Differential Equations, and Dynamics & Vibrations to supplement my education and enable me to perform meaningfully with my peers in simulation analyses. I started in plastics as a machine operator, then mold setup, then moved into processing, and finally into manufacturing engineering at Lescoa Inc. before transitioning into simulation at Hoff & Associates in 1999. In late 2001 I moved to Cascade Engineering, doing molding and structural analyses. I excelled at problem solving and over the years have devised analyses techniques that extended beyond the assumed limitations of the software tools available. I have been at Altair since November of 2007. I have supported many of our applications over the years and taught classes in both our front end applications and many of our solvers for mechanical, crash, CFD, and Manufacturing solutions. I have written some internal applications and authored a few training classes related to injection molding for Altair, including one due to be launched next year, "Polymer Properties for Simulation," which covers properties for simulating with polymers in the context of structures as well as rheological simulation.

Temperature-Dependent Anomalous Rheological Behavior of TPU Nanocomposites With Carbon Nanofillers

Summary

Multi-wall carbon nanotubes (MWCNTs), graphene nanoplates (GNPs), and hybrid fillers (MWCNTs/GNPs) filled thermoplastic polyurethane (TPU) nanocomposites are prepared via melt mixing. The effects of filler (contents of 1, 2, and 3 wt%) and temperature are investigated on the rheological behavior of the TPU nanocomposites. The results demonstrate that the TPU/MWCNT nanocomposites exhibit stronger polymer-filler and filler-filler interactions than TPU/GNP and TPU/GNP/MWCNT nanocomposites. It is found that the nanocomposites with 2 and 3 wt% MWCNTs (2CNT and 3CNT) and 3 wt% MWCNTs/GNPs (3Hybrid) exhibit anomalous rheological behavior. As rising the temperature from 180 to 190 ℃, the complex viscosity values slightly increase in the low frequency region (< 0.4 rad/s) for the 2CNT and 3Hybrid samples, and more significantly increases over a wider frequency range (up to about 10 rad/s) for the 3CNT sample. The Fourier transform infrared spectroscopy spectra demonstrate that the anomalous rheological behavior is not caused by hydrogen bonding in the TPU nanocomposites. The results of scanning electron microscopy observation, time sweep tests, and volume electrical conductivity measurements reveal that the anomalous rheological behavior is attributed to physical contact of the MWCNTs under low shear.

About the Speaker

Dr. Huang is the professor and academic leader of polymer processing and machinery at South China University of Technology (SCUT). He received his BS degree in polymer processing and machinery from SCUT in 1984, and Ph. D in polymer processing engineering from the same university in 1995. His research interest includes micro molding, polymer foaming, polymer processing rheology, and fluid assisted polymer processing. He has more than 280 journal publications, 38 patents, one book on blow molding and 7 book chapters.

Turnkey Solution for 3D Metal Printed Conformally Cooled Injection Mold Inserts

Summary

In Spring of 2020, Instaversal was contracted to test our newly developed conformal cooling technology, CoolToolTM, against existing production benchmarks for a plastic injection molded Pipe Bracket Adapter. The Product Innovator was going through a period of elevated demand where the current cycle time of the existing injection mold tool prohibited them from meeting their demand. When cooling cycles were sped up this led to higher scrap rates due to sink marks. This left the Product Innovator with two options: delay delivery of the product to their top customer with the risk of losing the sale and potentially losing the customer or to invest in additional injection mold tools to double production capacity. To meet the customer's demand, 100,000 parts needed to be produced in a 60-day time period. This request created conflict with the contract manufacturer. They were being asked to absorb the cost of additional molds to meet the timing or run full 24-hour (Monday-Friday) shifts over the 60-day period which would create losses in revenue by eliminating other clients' scheduled jobs.

About the Speaker

Zakary Tyler Smith holds a Bachelor of Science in Mechanical Engineering and Technological Entrepreneurship from Northeastern University in Boston, MA. Zakary has successfully launched over 100 products from concept through production across the aerospace, automotive, consumer, industrial and medical industries. Some notable products include the Tesla Model 3 Battery Pack, Google X Loon, Samsung Smartwatch and Ventec's ventilator which was utilized in the Defense Product Act during the Covid-19 pandemic. Taking products from conceptualization to mass production through co-developing innovative solutions with product innovators is Zakary's passion. Additional areas of expertise includes integrating artificial intelligence, machine learning, advanced manufacturing principles, materials design, industrial design, predictive engineering, regulatory/compliance, rapid prototyping, NPI, manufacturing and go-to-market strategies.

Changes in Polyamide 11 Microstructure and Chemistry During Selective Laser Sintering

Summary

A polyamide 11/carbon black (PA11/CB) SLS nanocomposite printing powder was characterized throughout a laser area energy density range (express by using Andrew's numbers, AN) to elucidate significant changes to the PA11 microstructure and chemistry during the SLS printing process. We will show that there are specific microstructural changes that occur in PA11, some gradual and others more striking, between the as received PA11/CB powder and printed parts. The melting temperature (Tm), percent crystallinity (Xc), lamellae thickness (lc) and dhkl spacing of PA11 were all shown to change significantly upon printing, whereas the molecular weight was shown to have a rather gradual increase as a function of AN. These results imply that the printing conditions used result in an irreversible change in PA11 polymer microstructure and chemistry, and correlate well to the measured mechanical behavior of parts print with corresponding AN. The use of DSC, XRD, and molecular weight analysis provides a more complete picture of the changes due to the SLS printing process and can help optimize the printing parameters to create high-quality printed parts.

About the Speaker

Dr. Gabrielle Esposito received her undergraduate degree from Georgia Institute of Technology in Polymer and Fiber Engineering, and her doctorate from Lehigh University in Polymer Science and Engineering. At Lehigh, she successfully defended her thesis titled "Mechanical behavior and characterization of SLS processed PA-11 for PA-11/silica nanocomposites" while working under Professor Ray Pearson. She is currently investigating the synthesis of high performance polymer powders for SLS printing at the University of North Carolina, working under Professor Theo Dingemans.

Keynote: Circular Charlotte

Summary

Envision Charlotte in partnership with the City of Charlotte, engaged Metabolic to analyze Charlotte’s waste stream and develop a strategy forward for the city. With Metabolic’s expertise in the Circular Economy, Envision Charlotte will lead Charlotte and the U.S in becoming more circular while creating more jobs, innovations, and a drive towards zero waste. Learn all about their current Plastics related projects including Send Me on My Way, the Plastics Lab and Litter Gitters.

About the Speaker

As Executive Director for Envision Charlotte, Amy Aussieker is responsible for developing strategic plans for community outreach, fundraising, vendor and partner relationships. Since she joined the team in July 2013, Amy has used her two decades of expertise in strategic planning, relationship management, marketing and creative problem solving to help Envision Charlotte become a global model of urban sustainability.

Amy’s background is a blend of corporate, non-profit and entrepreneur expertise. Before joining Envision Charlotte, Amy served as a strategic consultant for businesses and Chambers of Commerce in marketing, fundraising, social media and public relations. She spent several years as Group Vice President for Sales and Marketing for the Charlotte Chamber of Commerce, where she was responsible for leadership, fundraising and community relations. She also served as a business development and community affairs executive with Balfour Beatty Construction, and she founded, operated and recently sold a successful retail business.

Keynote: PCE, Past, Present, and Future.

Summary

The focus will be on our commitment to the polymers industry, and how we have fulfilled that mission, both in the past and present. I’ll finish with our plans for the future.

About the Speaker

Education

Ph.D. History of Science, 1991

• University of Wisconsin—Madison
• Major: History of Science
• Minor: American History
• Dissertation: “Ormsby MacKnight Mitchel and the Development of Astronomy in Antebellum America”
• Advisor: Ronald L. Numbers

BA, History, 1974

• University of Denver, Denver, Colorado
• Major: History
• Minor: Physics
• Advisor: Wolfgang Yourgrau

Professional Experience

1. May 2015, to the present, Executive Director, The Polymers Center of Excellence, Charlotte, NC.
2. January 2013, Pharmaceutical Pelletization Sales North America, Automatik Plastics Machinery, Charlotte, NC.
3. January 2011, Named General Manager, Maag-Automatik Inc., Charlotte, NC.
4. March 2008, Named President, Automatik Inc., Spartanburg, SC.
5. May 2005 to March 2008, Head Non-Woven and Pelletizing Machinery Sales, North America, Rieter Corporation.
6. September 1998 to April 2005 VP, Pelletizing Machinery Group, Rieter Corporation.
7. January 1995, to August 31, 1998, Sales Manager, Rieter Corporation, Spartanburg, SC.
8. 1982 – 1995, Vice President, General Manager, HMC Inc. Jamestown, NC 27282.
9. 1977-1981, Research and Teaching Assistant, University of Wisconsin-Madison, Department of History of Science.

View Complete CV

Keynote: Regulatory and Legislative Trends That Are Shaping the Future of Recycling and Plastics Policy

Summary

TBA

About the Speaker

Matt Seaholm is the President and CEO of the Plastics Industry Association (PLASTICS).

Prior to becoming President & CEO, Matt was the Vice President of Government Affairs where he oversaw the association’s legislative and regulatory activities. Matt joined PLASTICS in December of 2016 as Executive Director for the American Recyclable Plastic Bag Alliance, where he focused on communications, sustainability, and advocacy efforts dedicated to the plastic retail bag segment of the industry.

Before arriving at PLASTICS, Matt was Vice President of Public Affairs at communications and marketing firm Edelman, having helped clients navigate federal, state and local policy fights. He has an extensive background in issue advocacy, government affairs, and grassroots organization. He is also a veteran campaign manager with experience running campaigns on the legislative, congressional, statewide, and national levels. Matt is a native of Wisconsin and proud alum of the University of Wisconsin.

Keynote: Post-Pandemic Economic Outlook and Plastics Industry Prospects

Summary

TBA

About the Speaker

Perc serves as AFSA’s primary expert on economics, statistics, and industry research supporting the organization’s advocacy efforts.

He most recently served as the Chief Economist of the Plastics Industry Association tracking macroeconomic trends, conducting economic research, producing forecasts and report, business sentiment surveys, and enhanced industry data dissemination to members. Perc was also a Senior Economist of the Credit Union National Association, and previously, taught economics at the St. Francis College in New York, NY, and economics and finance at the City University of New York. Prior to a stint in academia, he was at the International Monetary Fund.

Perc received his PhD and MPhil in Economics from the New School of Social Research in New York, NY. He also holds an MA in Economics from the American University in Washington, DC, and a Master’s in International Management from the University of Maryland. He is a member of the National Association of Business Economist and a panelist of the Federal Reserve Bank of Philadelphia’s macroeconomic forecasters. His views on the economy and the industry have been widely quoted in the media; his research and insights have been published in peer-reviewed economic and trade journals.

Keynote: Title TBA

Summary

Today all businesses and industries continue to be challenged with hiring and retaining great talent and leaders. This is especially true in the plastics industry. The search for people with needed skill sets or the desire to learn and work in plastic manufacturing is becoming more problematic every day. Hiring people in need of a second chance is often overlooked by companies or simply disregarded due to company policy to screen out job applicants with a criminal record or prior drug/alcohol problems. This presentation will address the following approaches:

• Learn and understand the system of re-entry, re-integration, and recidivism 
• Care less about what a person “Did” and care more about what they will “Do” 
• Find the best release programs to work with your company

About the Speaker

Lloyd Martin is a 1983 graduate from Shawnee State University with a degree in Plastics and Chemical Technology. Since graduating, Lloyd has achieved over 35 years of work and leadership experience in manufacturing sites around the United States, with various packaging and engineering companies. Currently, Lloyd is the Sr. Vice President of Manufacturing and IT for CKS Packaging Inc. A plastic bottle manufacturer with 27 sites in the US and 3,100 employees. In his spare time, Lloyd enjoys traveling, working with non-profit organizations to serve others (Second Chance Programs), hiking, and trail running. Lloyd is an accomplished alumni and Board member to the Shawnee State University Development Foundation. He also serves on the Board of Directors for the Society of Plastics Engineers/Blow Molding Division.

Keynote: Best Practices for Recruiting, Retaining and Advancing Female Talent

Summary

Companies continue to find innovative ways to diversify their workforces to match their customer and consumer base. Moreover, it is not just about recruiting diverse employees; it is about retaining and developing their professional talents as well. This presentation will cover:

• Information on the representation of women in the U.S. workforce and in manufacturing
• Key ways to recruit, retain and develop women
• The impact that mentoring can have on recruitment, retention and advancement
• Current trends in career development and succession planning

About the Speaker

Allison Grealis is the Founder and President of the nonprofit trade association Women in Manufacturing (WiM). WiM started as a small networking group within the Precision Metalforming Association. What started as a networking group grew very quickly into a trade association operating independently of Precision Metalforming Association.

Keynote: Why Employing People With Disabilities is Good for Your Business

Summary

Did you know that 25% of the U.S. has a diagnosed disability and over 40% of our country will go through a long-term disabling condition in their life? People with disabilities are a powerful workforce for the plastics industry. In this session, James Emmett will discuss how strategically employing people with disabilities is good for your company. He will cover how to actively tap this workforce during the current labor shortage. He will review the business case such as reduced turnover, lower recruiting costs, improved safety, and consistent productivity. He will end the session by highlighting how people with disabilities enhance your diversity and bring new perspectives to old problems.

About the Speaker

James Emmett is a national leader in development of employment services for individuals with disabilities as well as in assisting corporations in creation of outreach efforts to the disability community. He is an individual with a disability and a parent of three daughters with disabilities.

James has worked on many of the most visible disability & inclusion projects in the country with companies like Walgreens, Best Buy, Office Depot/Max, PepsiCo, and Mercy Health. Working through APSE HR Connect, James serves as lead consultant for TIAA-CREF’s “Fruits of Employment” project.

In the past, James has worked as the initial Disability Program Manager for Walgreens helping set up the company’s national disability initiative. He also assisted Easter Seals National in laying the foundation for their national autism services network. James graduated with a Master’s Degree in Rehabilitation Counseling from Illinois Institute of Technology.

James has also worked with companies such as UPS, ABN Amro/LaSalle Banks, Century Tile, and the Brookfield Zoo in developing outreach efforts targeting the disability community. He served as the Project Director for three award winning research/demonstration projects examining career development and transition strategies for individuals with autism and other disabilities. These projects included the Vocational Alliance Autism Project (VAAP), the Business Approach to Social Integration & Communication (BASIC) Grant, & the EmployAlliance Employment Within Business Project. James co-authored a chapter on school to work transition in the book Employment for Individuals With Asperger Syndrome or Non-Verbal Learning Disability. He recently completed an article for the Journal of Vocational Rehabilitation entitled Lessons Learned By A Rehabilitation Counselor in Corporate America. He is currently writing a book entitled Business & Autism: The Desktop Guide on How Companies Target the Growing Autism Community. James has presented at over 200 national, state, and local conferences on issues related to career development, transition, the business community, and disability.

Also, in partnership with the West Suburban Chamber of Commerce & Industry, James helped develop and narrated a video entitled, “Improving Customer Service for People with Disabilities” which has been viewed over 16,000 times on YouTube.

James’ career vision is to forever change the business and disability communities by helping hundreds of companies create disability inclusion brands.

in-Depth Rheological Study of Acrylic Processing Aids for Rigid PVC Applications

Summary

Acrylic processing aids are used widely in rigid Polyvinyl Chloride (PVC) applications. Key functions of processing aids in terms of processing and performance are discussed in the paper. Effect of molecular weight of acrylic processing aids on their functions are studied. Additionally, effect of processing conditions, such as temperature and shear on fusion characteristics of PVC formulations, are investigated. Shear rate in the processing was varied by means of rotor speed in torque rheometer. Processing aids of wide molecular weight range are evaluated in the study. It was observed that relatively lower molecular weight processing aids have different response to change in shear and temperature than higher molecular weight processing aids. Depending upon fusion conditions PVC formulations can yield either single or double fusion peak. Generally, it was considered that ultra-high molecular weight processing aids yield double fusion peak, however, it was demonstrated in the studies that it is not true. Fusion conditions, temperature, and shear are the main driving forces of fusion dynamics, resulting in either single of double fusion peak. Melt viscosity and shear thinning properties are also examined. Relatively lower molecular weight processing aids showed higher shear thinning behavior.

About the Speaker

Dr. Manoj Nerkar is the Senior Technical Service and Development Scientist at Dow Plastics Additives. Dr. Nerkar received Ph.D. in Polymers at Queen's University, Canada and has over 17 years of industrial experience in the field of Polymer blends, composites, polymer processing and characterization and polymer structure properties. From last five years his research focus is in PVC industry, specifically on acrylic processing aids and impact modifiers for PVC and engineering resins including Polycarbonate and its blends. Dr. Nerkar is member of Board of Directors for SPE's Building and Infrastructure Division. He published numerous journal papers, conference presentations, patents and patent applications. His employment history is as follows: Dow Inc, USA, 2016 to present Sr. Scientist, Tech Services Expertise includes acrylic processing aids and impact modifiers for rigid PVC in various applications including resilient flooring, PVC foaming, window profile and PVC compounding. TerraVerdae Bio Works , Canada, 2014 to 2016, Product Development Scientist Product development for biopolymers such as Polyhydroxyalkanoates (PHA) and Polylactic acid (PLA) GE Plastics, India, 2004 to 2010 Scientist Polymer processing, FR and low smoke technology, Specialty polymers PolyPhenylene Oxide (PPO) Solvay, India, 2003 to 2004, Application Development Scientist High temperature polymers, Polysulfone and Polyether ether ketone (PEEK)

Injection Molding of Microporous Ultra-High Molecular Weight Polyethylene

Summary

Microporous ultra-high molecular weight polyethylene (UHMWPE) parts were produced by microcellular injection molding (MIM) technology, which enabled higher production efficiency and lower part cost compared to the traditional powder sintering method. The microstructure could be tuned by adjusting the shot size to produce either sandwiched solid-skin " porous-core " solid-skin parts or open porous parts. The pore morphology, average pore size, pore size distribution, and pore density were characterized, and the water contact angle (WCA) and degree of oil-water separation were determined. The part weight reduction of open-porous UHMWPE and sandwiched UHMWPE parts were 16.5 wt% and 11.8 wt%, respectively. The WCA results showed that the porous surface transformed molded UHMWPE samples from being hydrophilic (34.5°) to hydrophobic (124.6°). Furthermore, the open-porous structure exhibited good oil-water separation capacity. Tensile tests were carried out to study the effect of morphology on the mechanical performances of the molded UHMWPE parts. The characterization shows that a possible application for the sandwiched UHMWPE parts could be as a bone replacement material because of its high mechanical performance, and an application for the open-porous UHMWPE is as a functional filter material due to the fine pore size and high pore density.

About the Speaker

Huaguang Yang is currently a postdoc in Wisconsin Institutes for Discovery and Department of Mechanical Engineering at UW-Madison. His research interests mainly focus on innovative injection molding technologies, polymetric foams and nanocomposites.

Using In-Mold Switches for Control and Monitoring of a Multi-Cavity Hot Runner Mold

Summary

The use of in-mold melt-front detecting switches were used to control the velocity-to-pressure (v/p) transfer during injection and/or to monitor the injection in a 2-cavity, hot runner valve-gated mold. The switches were connected to a data acquisition/control system either independently, in series or in parallel. When the switches were not used for v/p transfer, screw position was used. It was found that using the in-mold switches for monitoring was more effective than either peak injection pressure or cushion monitoring to sort suspect parts and alert of changes in cavity balance. When the switches were either hooked up in parallel or independently, using the first switch closed for v/p transfer, overpacking of the mold was prevented when the heater in the drop/gate of one cavity was turned off.

About the Speaker

Brad Johnson has been teaching at Penn State Erie, The Behrend College's plastics engineering technology program since 1994. Prior to joining Penn State, he accumulated over ten years of industrial experience and served in various roles in the plastics industry: manufacturing engineer, manufacturing supervisor, design engineer, and program manager. His primary expertise is in injection molding and process optimization. Along with developing some of the processing classes, he has also taught plastic materials, mold design, rheology, and quality control classes. Brad also directs the Plastics Training Academy (PTA) at Penn State, which offers short non-credit classes on plastics-related topics. He has taught many short classes on injection molding for the PTA, both at Penn State and on-site. He also organizes and chairs the Innovation and Emerging Plastic Technologies conferences that are held in Erie. Brad holds bachelor's and master's degrees in chemical engineering from Virginia Tech. He is also an active member and a past chair of SPE Injection Molding Division.

Improving Part Properties During Injection Molding With 3D Printed CO₂Cooled Plastic Mold Inserts

Summary

This paper describes the development of innovative temperature control concepts for use in additively manufactured inserts based on CO2. These have been successfully investigated for their suitability in small batch production. The additive manufacturing processes have been evaluated in terms of their suitability for the production of mold inserts. It has been possible to reduce the time required to prepare the inserts. In the investigation of suitable plastics, POM has proven to be suitable. Of the generative manufacturing processes investigated, stereolithography was found to be suitable. Robust manufacturing in the injection molding process with the other additive manufacturing processes was not possible. The manufactured components were examined with regard to their properties and compared with conventionally injection-molded components. It was found that a clear dependence on the manufacturing process of the insert used for production can be observed, especially in the crystalline microstructure of the manufactured components. This makes it difficult to use additively manufactured tool inserts in small-batch production, since the resulting properties of the components in terms of crystallinity and thus distortion are not comparable with injection-molded components. In further investigations, the minimum necessary thermal properties of the printing materials must be determined in order to ensure robust small series production with component crystallinity comparable to the injection molding process.

About the Speaker

Ruben Schlutter studied Mechanical Engineering at the University of Schmalkalden. After his graduation he started working as research associate in the laboratory of Applied Plastics at the University of Applied Sciences in Schmalkalden. Here he wrote his ph.D. thesis in the field of injection molding Simulation. From 2016 to 2022 he worked at Plastics Institute for SMEs in North Rhine Westphalia. Since 2022 he is woking as self-employed lecturer.

Machine Learning Modeling to Predict Transient Cavity Pressure Profile in Injection Molding Process

Summary

A machine learning approach based on artificial neural network is presented and applied to injection molding process. Fill time, maximum fill pressure and transient cavity pressure profiles are predicted with the input process conditions of injection speed, melt temperature and mold temperature. The physics based model using Autodesk Moldflow is evaluated by comparing it with experimental fill pressure profiles for various process conditions, and it is used to generate enough data to train and validate the machine learning model. With the present machine learning model using 400 data samples, not only the fill time but also the transient pressure profiles are accurately predicted with less than 4.7% error. Further, a new machine learning model is trained with 200 data samples, instead of 400 samples, to check the dependence of the model accuracy on the sample size, and the error in prediction of transient pressure profiles increases only to 6.7%.

About the Speaker

On-Line Measurement of Plastic Melt Density for Injection Molding Using Ultrasonic Technology

Summary

Density is an important factor that influences the quality of the injection molded products, and density variation during the injection molding process contains valuable information for process monitoring and optimization. Therefore, on-line density measurement is of great interest and has significant application value. The existing methods, such as Archimedes-principle-based method and Pressure-Volume-Temperature (PVT) method, have the shortages of time-delay and high cost of sensors. As the first attempt, this study proposed an on-line density measurement method based on the analysis of ultrasonic signals. The analysis of the time-domain and frequency-domain signals were combined. The ultrasonic velocity was obtained from the time-domain signals and the acoustic impedance was computed through a full-spectrum analysis of the frequency-domain signals. The proposed method was verified to be accurate with the root mean square error (RMSE) of 0.0245 g/cm3 and the maximum relative error of 6.48%. Experiments with different process conditions were conducted, including different melt temperature, materials, and mold structures. The results indicate that the proposed method is in good agreement with the PVT method, and the RMSE is within 0.0333 g/cm3 and the maximum relative error is within 7.99%. The proposed method has the advantages of on-line, non-destructive, high accuracy, and low cost, and is of great application value to be utilized by the injection molding industry.

About the Speaker

Professor Lih-Sheng (Tom) Turng received his B.S. degree in Mechanical Engineering from the National Taiwan University, and his M.S. and Ph.D. degrees from Cornell University. He worked at C-MOLD developing advanced injection molding simulation software for 10 years before joining UW–Madison in 2000. His research encompasses injection molding, nanocomposites, multi-functional materials, bio-based polymers, and tissue engineering. Professor Turng is currently the Consolidated Papers Professor and the Co-Director of the Polymer Engineering Center and Group Leader at the Wisconsin Institute for Discovery (WID), a Fellow member of the American Society of Mechanical Engineers (ASME), the Society of Plastics Engineers (SPE), and the Society of Manufacturing Engineers (SME), the recipient of the 2018 Wisconsin Alumni Research Foundation (WARF) Innovation Award, and an Honored Service Member of the SPE. Professor Turng has published 300 refereed journal papers and over 250 conference papers/presentations and has 12 Best Papers awards and 20 patents and patent applications.

Investigating the Processing of Stimuli-Responsive Cellulose Nanocrystal Polymer Composites In Graded 3D Printing

Summary

The movement to transfer from petroleum-based products and materials to renewables does not necessarily have to bypass the use of oil. A new type of "black-gold" is readily abundant from the earth's most abundant source of aromatic carbon: lignin. While fractionation of petroleum yields fuels and chemicals for a diverse set of industries, lignin fractionation using targeted catalysts has demonstrated the ability to generate monomers and oligomers rich in functional groups for polymer synthesis. This study explores the use of lignin-oil, generated from reductive catalytic fractionation of popular wood, to a hydroxyl-rich mixture of aromatics that is used to synthesize a thermoplastic non-isocyanate polyurethane. The lignin-oil is first converted to a cyclocarbonated derivative using a benign synthetic sequence and further polymerized with a diamine to yield the non-isocyanate TPU. While more work is underway to optimize the reaction conditions and meet typical mechanical properties of commercial materials, initial analysis shows thermoplastic behavior and flexible properties consistent with traditional thermoplastic polyurethanes.

About the Speaker

James Sternberg is a Senior Scientist at the Clemson Composites Center studying biobased and recyclable-by-design polymers. His initial background is in chemistry, receiving a bachelor's degree from Furman University and a master's degree in chemistry from the University of Florida. After many years as a high school teacher, James has completed his Ph.D. under Dr. Srikanth Pilla at Clemson's International Center of Automotive Research.

Functionalization of Engineering Plastics with Biocidal Nano-Particles

Summary

Increased demands on all possible materials put the focus of development on novel functionalities such as, among others, biocidal effects, which are made possible due to property changes in the nanoscale range of existing materials or by combining different material classes. This paper shows a method to achieve biocidal effects with the help of nanoparticles from transition metal oxides. These were compounded into plastic granules and lacquer to transfer the biocidal properties on plastic part surfaces.

About the Speaker

Ruben Schlutter studied Mechanical Engineering at the University of Schmalkalden. After his graduation he started working as research associate in the laboratory of Applied Plastics at the University of Applied Sciences in Schmalkalden. Here he wrote his ph.D. thesis in the field of injection molding Simulation. From 2016 to 2022 he worked at Plastics Institute for SMEs in North Rhine Westphalia. Since 2022 he is woking as self-employed lecturer.

Zirconium Dioxide as a Thermo-Insulating Coatins for Molds in Plastic Injection Molding

Summary

Effect of the thermal barrier coating (TBC), deposited on the mold for plastic injection molding was investigated. The mold cavities were coated by yttrium stabilized (YSZ) and phosphorous doped (PDZ) zirconium dioxide as multilayer film using chemical vapor deposition (CVD) method. It was found that films deposited at higher temperatures have better thermo-insulating properties than films deposited at lower temperatures. Growth rate and film porosity increase as deposition temperature increases. It was observed that the TBC slightly affects the flow length of the plastic melt but improves the filling ability of poorly vented molded part areas.

About the Speaker

Ruben Schlutter studied Mechanical Engineering at the University of Schmalkalden. After his graduation he started working as research associate in the laboratory of Applied Plastics at the University of Applied Sciences in Schmalkalden. Here he wrote his ph.D. thesis in the field of injection molding Simulation. From 2016 to 2022 he worked at Plastics Institute for SMEs in North Rhine Westphalia. Since 2022 he is woking as self-employed lecturer.

ABS/Carbon Fiber Composite Foams with Bimodal Fine-Cell Structure Prepared using Supercritical CO₂

Summary

Cyclic olefin copolymers (COC) provide manufacturers and converters with an opportunity to create thin, stiff, high performance polyolefin packaging products. COC provides an unexpected, but essential benefit that enables the manufacture of high-density polyethylene (HDPE) containers by reheat injection stretch blow molding. COC has good dimensional stability and excellent heat resistance, minimizes distortion of PE exposed to thermal and mechanical stresses.

About the Speaker

Paul D. Tatarka is in Market Development for Polyplastics USA, Inc. based in Farmington Hills, MI. In this role, he is responsible for promoting TOPAS® cyclic olefin copolymers in flexible packaging and emerging market applications. In his 30-year career, Paul has developed and commercialized new copolymers, compounds, shrink, and medical packaging films. He holds twelve US patents. Paul holds Master of Science in Plastics Engineering and Bachelor of Science in Chemical Engineering, both from the University of Lowell and MBA in Finance from Farleigh Dickinson University.

ABS/Carbon Fiber Composite Foams with Bimodal Fine-Cell Structure Prepared using Supercritical CO₂

Summary

Via two-step solid-state foaming using subcritical CO2 as blowing agent, the foamed acrylonitrile-butadiene-styrene/carbon fibers (ABS/CFs) composites are prepared. The results demonstrate that a bimodal cell structure (BMCS) is developed in the foamed ABS/CFs composites. Small and denser cells are developed in the ABS matrix, whereas large cells are formed around the CFs due to concentrated CO2 at the ABS CFs interfaces interfaces. The mean cell diameters are 0.39â "0.92 μm for the small cells and 12.5â "25.6 μm for the large cells, being dependent on the CFs content. The CFs especially at 10 wt% or higher can refine the small cells via both increasing the strength and elasticity of the ABS matrix and restricting their growth under large cell growth. Interestingly, slow depressurization for the saturated composites followed by foaming is also favorable to refine the small cells, which is mainly attributed to no cells to be preformed in the saturated composite via the slow depressurization. Relatively higher saturation pressure or modest foaming temperature can further refine the BMCS in the foamed ABS/CFs composites.

About the Speaker

Dr. Huang is the professor and academic leader of polymer processing and machinery at South China University of Technology (SCUT). He received his BS degree in polymer processing and machinery from SCUT in 1984, and Ph. D in polymer processing engineering from the same university in 1995. His research interest includes micro molding, polymer foaming, polymer processing rheology, and fluid assisted polymer processing. He has more than 280 journal publications, 38 patents, one book on blow molding and 7 book chapters.

Understanding the Effects of Process Parameters on the Curing of Hexcel AS4/8552 Prepreg Composites

Summary

The effects of the processing parameters on the curing of continuous carbon fiber composite made from Hexcel AS4/8552 prepreg tape are studied. A commercial process simulation finite element method, that takes in account the residual stresses due to chemical, thermal, and mechanical shrinkages, is utilized. This method solves the curing process sequentially. In the first step, the distribution of temperature and degree of cure in the composite is computed. In the second step, the information from the previous step is used to calculate the stress evolution during cure. At the end of the second step, the composite deformation due to tool removal is also calculated. The impact of three different process parameters on the final degree of cure and the residual stresses are studied in detail.

About the Speaker

Dr. Shardul Panwar is a Senior Research Scientist in the Future Mobility Research Department (FRD) of the Toyota Research Institute of North America. Dr. Panwar conducts applied research in the areas of fabric-based inflatable structures for renewable energy generation, advanced composite materials for energy storage, smart material and electroactive polymer actuators for soft robotics, conductive ink and fiber optic-based embedded structural sensors for structural health monitoring, and reusable energy absorbing structures for sustainability. Dr. Panwar is particularly interested in developing innovative technologies for future mobility and aerospace applications. He has authored or co-authored multiple journal articles and has filed multiple patents in pursuit of this goal.

The Development of a Flexible Spout for Flexible Packaging

Summary

Flexible packaging has seen significantly rapid growth in recent years because of its many advantages, such as light-weight and compact design as well as high sustainability. In this paper, the development of a novel flexible spout (fitment) for flexible pouch applications is presented. This flexible spout has a cylindrical base, and thus can be manufactured more efficiently, consistently, and cost-effectively than rigid spouts with winglets. Since it is made of flexible materials such as INFUSEâ„¢ Olefin Block Copolymer and Polyethylene blends, it provides comfort for the end user and improves user experience. The key to the successful production of hermitic flexible pouches with this flexible spout is to form winglets in-situ during the heat sealing process. Both finite element (FE) modeling and experimental techniques were used extensively through this work, which demonstrates that the effective utilization of these tools combined with engineering judgment can efficiently solve complex and challenging real-world problems, and significantly accelerate the new product development process.

About the Speaker

Liangkai Ma is a research scientist specializing in new mechanical modeling capabilities and test methods development. During his 11 years' working experience with Dow, he has led many projects that resulted in innovative solutions to customers across different market segments including light weighting, flexible packaging, renewable energy, and transportation. Liangkai holds a Ph.D. in Mechanical Engineering from Michigan State University. He currently has 8 granted patents and has published 27 journal and conference technical papers. He has been a member of SPE, ASC, SAMPE, and NAFEMS.

Temperature-Dependent Anomalous Rheological Behavior of TPU Nanocomposites With Carbon

Summary

Multi-wall carbon nanotubes (MWCNTs), graphene nanoplates (GNPs), and hybrid fillers (MWCNTs/GNPs) filled thermoplastic polyurethane (TPU) nanocomposites are prepared via melt mixing. The effects of filler (contents of 1, 2, and 3 wt%) and temperature are investigated on the rheological behavior of the TPU nanocomposites. The results demonstrate that the TPU/MWCNT nanocomposites exhibit stronger polymer-filler and filler-filler interactions than TPU/GNP and TPU/GNP/MWCNT nanocomposites. It is found that the nanocomposites with 2 and 3 wt% MWCNTs (2CNT and 3CNT) and 3 wt% MWCNTs/GNPs (3Hybrid) exhibit anomalous rheological behavior. As rising the temperature from 180° to 190°, the complex viscosity values slightly increase in the low frequency region (< 0.4 rad/s) for the 2CNT and 3Hybrid samples, and more significantly increases over a wider frequency range (up to about 10 rad/s) for the 3CNT sample. The Fourier transform infrared spectroscopy spectra demonstrate that the anomalous rheological behavior is not caused by hydrogen bonding in the TPU nanocomposites. The results of scanning electron microscopy observation, time sweep tests, and volume electrical conductivity measurements reveal that the anomalous rheological behavior is attributed to physical contact of the MWCNTs under low shear.

About the Speaker

Dr. Huang is the professor and academic leader of polymer processing and machinery at South China University of Technology (SCUT). He received his BS degree in polymer processing and machinery from SCUT in 1984, and Ph. D in polymer processing engineering from the same university in 1995. His research interest includes micro molding, polymer foaming, polymer processing rheology, and fluid assisted polymer processing. He has more than 280 journal publications, 38 patents, one book on blow molding and 7 book chapters.

Enhancing EMI Shielding Performance of Thermoplastics With Long Steel Fibers and Carbon Fibers

Summary

Electromagnetic interference (EMI) is a common problem encountered by electronic devices, especially in electric vehicles. External electromagnetic (EM) waves affect the operation of an electronic device by interfering with the internal EM signals. To provide EMI shielding, various materials were studied, and the measured electromagnetic shielding effectiveness (SE) data are presented in this study. The main factors affecting EMI SE are quantified statistically " filler loading, shield thickness, and base polymer resin matrix. Long steel fiber thermoplastics provide the highest EMI SE, at over 60 dB at frequencies ranging from 30 MHz to 20 GHz, and at thickness as low as 1.6 mm. It is also demonstrated that carbon fiber filled thermoplastics can provide EMI shielding at levels greater than 50 dB.

About the Speaker

Prabuddha Bansal is a principal engineer at Celanese Corporation. He covers various material developments and applications, including EMI Shielding, thermally conductive polymers, and high-heat thermoplastics. He has been working at Celanese since 2011. Various other research interests include process engineering, six-sigma and data-science, electric vehicles, and powertrain applications. He received his Ph.D. in Chemical Engineering from Georgia Tech.

Deformation Mechanisms of Toughened Poly(Lactic Adic) Using Novel Additives

Summary

Poly(lactic acid) (PLA) is certified biodegradable under specific composting conditions, but its inherent brittleness limits usefulness in commercial applications. In this study, novel additives were supplied by TRuCapSol for twin-screw melt compounding and injection molding with general purpose PLA resin. These additives were received in powder form and investigated for their ability to improve the tensile toughness. We compared our blends to several commercially available toughened PLA blends. The inherent micro-deformations of PLA were amplified by the novel additive and resulted in improved ductility. Therefore, the potential for the development of blends that enhances the toughness and increase the rate of biodegradation of PLA has been demonstrated.

About the Speaker

Jordan L. Greenland was born and raised in State College, Pennsylvania. Before pursuing a Master of Science and Doctor of Philosophy in the field of Polymer Science and Engineering at Lehigh University in Bethlehem, Pennsylvania he earned a Bachelor of Science degree in Plastics and Polymer Engineering Technology and Minor degree in Management at the Pennsylvania College of Technology (PCT) in Williamsport, Pennsylvania. Jordan graduated with Magna Cum Laude honors in 2019. During his undergraduate studies Jordan participated in various student organizations such as the Society of Plastic Engineers Susquehanna Student Chapter, Favors Forward Foundation, and Campus Crusade for Christ. He was also employed by PCT as a mathematics and physics part-time tutor. Jordan also obtained a 4-year Green Belt Certification in Lean Six Sigma Manufacturing at Penn State Behrend Land-grant University in Erie, Pennsylvania. During his graduate studies at Lehigh University Jordan received a certificate of completion for participation in level one of the Teacher Development Program. He also received a certificate of appreciation for outstanding contributions to the Pennsylvania Department of Community and Economic Development Manufacturing Innovation Program in partnership with TRuCapSol LLC. and Lehigh University. Currently, Jordan is a graduate student working as a Research Assistant and Teaching Assistant at Lehigh University.

GLIM: GLas Fabric Insert Molding - Polymer Back-Injection of Glass Fabrics to Increase Strength

Summary

Hybrid materials nowadays are achieving increasing market dominance in the technical segment due to their outstanding mechanical properties. One such hybrid material that is increasingly coming into focus, especially in mobility branch, are fiber-reinforced plastics. They offer the advantage of low weight and high strength. As a rule, generally glass or carbon fibers are embedded in the matrix material. Over the last few years, the demand for fiber-reinforced plastics has increased continuously. Considering the recent changes in the automotive industry, it is expected that this trend will not change in the near future, especially with regard to the weight reduction of means of vehicles. In this project, a process was developed to implement continuous fiber mats in injection molding. With the aid of modern production methods, it was impressively demonstrated that the mechanical characteristics of a PP could be significantly increased by inserting and back-injecting glass fiber mats.

About the Speaker

Ruben Schlutter studied Mechanical Engineering at the University of Schmalkalden. After his graduation he started working as research associate in the laboratory of Applied Plastics at the University of Applied Sciences in Schmalkalden. Here he wrote his ph.D. thesis in the field of injection molding Simulation. From 2016 to 2022 he worked at Plastics Institute for SMEs in North Rhine Westphalia. Since 2022 he is woking as self-employed lecturer.

Welding of Dissimilar Polymers

Summary

Joining of dissimilar polymers is traditionally accomplished via the use of adhesives or mechanical methods such as fasteners, snap fits, and staking. However, it may be possible to directly weld or bond polymers that are miscible but have different material properties via welding techniques. In this work, infrared welding was used to join acrylonitrile butadiene styrene to polyphenylene oxide. Through the use of targeted heating to match the polymer viscosities to each other, the weld strength was improved by up to three times.

About the Speaker

Miranda is responsible for leading EWI's technical expertise for all plastic and composite welding technologies. She has a PhD (2020) in Polymer Engineering from the University of Akron, and a masters (2006) and bachelors (2005) in Welding Engineering from The Ohio State University.

Ultrasonic Joining of Additively Manufactured Metal-Polymer Lightweight Hybrid Structures

Summary

Ultrasonic joining is a novel friction-based joining technique to produce through-the-thickness reinforced hybrid joints between surface-structured metals and unreinforced or fiber-reinforced thermoplastics. The reinforcements' presence is responsible for improving the out-of-plane strength of the parts, enhancing their damage tolerance. The process feasibility has been successfully demonstrated to join additively manufactured (AM) metal and polymer parts. However, further investigation of its main advantages and the joining process of subcomponents to support the technique's further development is still missing. This paper aims to demonstrate the application of U-Joining to fabricate AM 316L and PEEK hybrid structures produced via laser powder bed fusion and fused filament fabrication, respectively. Firstly, the quasi-static single lap shear performance of coupon specimens produced with optimized joining parameters was assessed. The results indicate an improvement of 2.7 times in the ultimate lap shear force and 5.9 times in the displacement " when compared to non-reinforced flat samples. Fracture surface analyses of tested samples exhibited a mixture of cohesive and adhesive failure. Further microstructural analyses at the metal-polymer interface showed micromechanical interlocking between the parts. As observed, the PEEK was able to flow and penetrate the cavities at the metallic specimen's rough surface due to the joining friction heat input. Finally, a selected skin-stringer-bracket case study was analyzed, showing the potential of AM and U-Joining to drastically reduce the structure's weight by about 64%. To validate this idea, a scaled-down skin-stringer-bracket technology demonstrator was successfully fabricated.

About the Speaker

Willian Carvalho is a PhD candidate at Graz University of Technology (TU Graz) and project assistant in the BMK Endowed Professorship for Aviation at the Institute of Materials Science, Joining and Forming - Austria. Willian concluded his bachelor in Materials Engineering at the Federal University of Sao Carlos (UFSCar) - Brazil, in cooperation with Helmholtz Center Geesthacht, Germany in the area of friction-based joining technologies.

Effect of Plasticizer Content in EPDM on Ex-Situ Wear Test After High Pressure Hydrogen Exposure

Summary

The material properties of fiber reinforced plastics are highly directional and the final fiber orientation can usually only be determined after the manufacturing process by time-consuming and cost-intensive sample preparation. The determination of the mechanical properties usually requires destructive testing. Compared to conventional methods, the method of ultrasonic birefringence presented here allows a non-destructive determination of the shear moduli G13 and G23. Furthermore, it allows the determination of the fiber orientation without the need of a complex specimen preparation. The difference in shear modulus measurement between the two methods is less than 1 %.

About the Speaker

Byeonglyul Choi is graduate student in school of mechanical engineering at Korea university. He is currently working on evaluating mechanical and tribological properties of elastomer under hydrogen environment.

Evaluation of Shear Modulus Using Destructive Shear Test and Non-destructive Ultrasonic Shear Waves

Summary

The material properties of fiber reinforced plastics are highly directional and the final fiber orientation can usually only be determined after the manufacturing process by time-consuming and cost-intensive sample preparation. The determination of the mechanical properties usually requires destructive testing. Compared to conventional methods, the method of ultrasonic birefringence presented here allows a non-destructive determination of the shear moduli G13 and G23. Furthermore, it allows the determination of the fiber orientation without the need of a complex specimen preparation. The difference in shear modulus measurement between the two methods is less than 1 %.

About the Speaker

• Research Associate at Institut für Kunststofftechnik | Universität Stuttgart since 2017
• Master of Science in Aerospace Engineering

Effect of Seal Pressure on Leak Resistance of Rigid Hot Tool Sealing Over Film Thickness Transitions

Summary

In flexible packaging, film thickness transitions can be problematic regions to seal due to their propensity for leaking, as well as the high seal pressure required to create a continuous seal over the transition. A compliant anvil can be used to decrease the required seal pressure, as the hot tool will be able to contact both the thick and thin regions of the packaging, with compression of the compliant anvil. However, a compliant anvil cannot be used in a double-sided heating process. Therefore, in a double-sided heating process, high seal pressures must be utilized in order to reduce the film thickness in the thick region, to facilitate tool to film contact in the thin region. In this study, the required seal pressure needed to create continuous (non-leaking) seals over a 4-film to 8-film thickness transition was explored, with both a rigid and conformable anvil. With a rigid anvil 3.25 MPa was required to consistently create continuous seals. With a conformable anvil 0.87 MPa was required to consistently create continuous seals.

About the Speaker

Flint Colvin is a PhD student studying welding engineering at The Ohio State University under the supervision of Professor Avi Benatar. Flint has his B.S. (2019) and M.S. (2021) in welding engineering from OSU. His previous research experience includes ultrasonic consolidation of advanced composites for armor applications, and development of a conformable sealing process for consumer products. Flint's current PhD work involves developing a joining solution for metallized polymer current collectors for Li-ion batteries. Flint is also working towards a graduate interdisciplinary specialization in data-driven sustainable energy solutions with OSU’s NSF research traineeship program.

Stress Corrosion Crack Growth of Polyethylene with Cracked Round Bar Specimen in Chlorinated Medium

Summary

In this study, the stress corrosion crack (SCC) growth model for the cracked round bar (CRB) specimen was developed. The axisymmetric crack layer (CL) theory for simulating the slow crack growth (SCG) behavior of CRB specimen was modified to consider the chemical degradation due to diffused aggressive environment. The diffusion of oxidative fluid into the process zone (PZ) in radial direction is considered. Also, the chemical degradation kinetics of PZ materials due to the oxidation were modeled. The proposed model was shown that the discontinuous SCG behavior and the deteriorative effect from the chemicals were successfully simulated.

About the Speaker

Professor Byoung-Ho Choi received his Ph.D. in Applied Mechanics from Korea University in 2001. He is currently a professor at the School of Mechanical Engineering at Korea University. His current research interests include the reliability and durability of engineering polymers, mechano-chemical degradation under extreme environments, theoretical and experimental fracture mechanics, and failure analysis.

Fibril-Flash Formation During Vibration Welding

Summary

Vibration welding flash occurs when molten polymer flows under pressure from the weld interface. This study examines the formation of small hair-like fibrils during vibration welding. Polypropylene and nylon 6 plates were butt-welded and the assemblies were assessed using a high-speed camera and digital microscopy. A mechanism has been proposed whereby initial asperities at the weld interface first melt to form a polymer pool. Thermal expansion of this pool allows polymer to be extruded laterally towards the edge of the weld interface. The extrudate is rolled up to form fibrils that can eventually grow to several millimeters in length.

About the Speaker

Philip Bates graduated in 1985 with his undergraduate degree in Chemical Engineering from Queen's University in Kingston Ontario. After graduation, he worked in product development for Procter & Gamble in Hamilton Ontario. He then went to McGill University in Montreal Quebec to get his Master's and PhD degrees in the area of thermoplastic composites. While pursuing graduate studies, Phil worked in the research labs of Vetrotex in Chambéry France. Following graduate school, Phil worked as a technical service engineer at Solvay Advanced Polymers in Brussels Belgium. In 1996, he took up an academic position in the Department of Chemistry and Chemical Engineering at the Royal Military College of Canada in Kingston Ontario where he became a Professor and Canada Research Chair in Polymer Processing and Joining. Phil has been slowly making his move to the dark side of university administration. He was Dean of Engineering at RMC from 2010 to 2014. Following a brief stint as VP Research, Phil assumed the role of Vice Principal Academic at RMC in 2015.

Moisture sensitivity characterization in PLA/PBS parts during Ultrasonic Welding

Summary

Ultrasonic welding (USW) is a surface mating process where absorbed moisture in the surfaces of hydrophilic materials can negatively affect the weld joint quality and strength. USW is a secondary processing operation that is performed post-molding or extruding. Hence, during the storage time between primary processing and USW, the parts are susceptible to moisture absorption. Therefore, it is necessary to characterize the moisture sensitivity to meet the specified weld strength. Moisture sensitivity of Industrial standard test parts (ISTeP) made with PLA, PBS, and PLA/PBS 25/75 blend was characterized for USW in this study. ISTeP parts were moisture conditioned for one week at different relative humidity (RH) levels and then tested for weld strength. It was found that the weld strength decreased with an increase in RH for 100% PLA ISTePs but it was not statistically significant. Above 65% RH, weld strength of 100% PBS was significantly decreased. Scanning electron microscopy of weld areas after the pull test revealed an increased amount of trapped porosity in the fractured surfaces of high relative humidity samples. It was also demonstrated that PBS and PLA/PBS composite can be ultrasonic welded.

About the Speaker

Raihan Quader is a PhD student in the Department of Industrial and Manufacturing Engineering at North Dakota State University (NDSU). He also completed his Master of Science in Manufacturing Engineering from NDSU. His Bachelor's degree was from Khulna University of Engineering & Technology, Bangladesh in Industrial and Production Engineering. His research is focused on additive manufacturing and ultrasonic welding of bioplastics and biocomposites. He has been working on several CB2 (Center for Bioplastics and Biocomposites) projects since the beginning of his graduate studies. Before coming to the USA, he worked in mold development of plastic products in a reputed company of Bangladesh.

Relative Humidity Effects on Accelerated Aging of Medical-Grade Polymers

Summary

ASTM F1980 provides a methodology for accelerated aging of sterile barrier systems for medical devices, and is also widely used as the definitive guide for accelerated aging of medical devices and pharmaceutical packaging. ASTM F1980-16, as well as previous versions going back to 2007, emphasize that when increasing temperature to accelerate aging, it is preferable to decrease relative humidity so as to maintain an approximately constant moisture content. However, there is a revision under consideration by the ASTM F02.50 committee that would dramatically change this guidance to indicate a preference (although allowing for other options) to keep relative humidity approximately constant. This change is based on somewhat limited test data and literature review published recently by Thor et al. In this paper, we perform a study looking at eight resins (PP, COC, ABS, PC/PET, Copolyester, PBT, PA66gf, PUR) that have been aged at 60C and three different RH levels to evaluate the impact on aging. Our findings to date indicate that: (i) yes, it is preferred to keep RH constant when increasing temperature in order to keep the moisture constant in the resins the same; and (ii) for the medical-grade resins evaluated here, RH level does not significantly impact the physical aging mechanism. We also recommend that further accelerated aging studies are performed to more thoroughly evaluate the impact of moisture content on Q10 factors, corrosion rates, and other endpoints before this dramatic change is made to the ASTM F1980 standard.

About the Speaker

Andy has 10 years of polymer science experience with a specialty for reactive polymeric systems such as adhesives and coatings. He brings a deep background in structure property relationships of thermoplastic and thermosetting polymeric systems, mechanical and thermal characterization of thermoplastic and crosslinkable systems. Andy also holds 15 patents for novel crosslinking strategies. Experience in the development of product concepts and value propositions for novel technologies. Proficient in lean startup principles for strategic business growth as it applies to Materials Science companies through efficient R&D focused on robust screening experimental design and controls and data driven decision making Graduate Training: PhD in Materials Science at University of Cincinnati Undergraduate Training: Bachelors of Engineering in Polymers, University of Pune, India

Simulation of Polymer Imprinting and Embossing using Smoothed Dissipative Particle Dynamics

Summary

A simulation of an imprinting process using Smoothed Dissipative Particle Dynamics is shown. Cavity filling modes and their dependence on die parameters is demonstrated for single and multi-cavity die, showing results consistent with FEM simulations and experimental data. Particle-based simulation methods can allow for modeling of more complex fluid behaviors.

About the Speaker

James St Julien is a graduate student at the Georgia Institute of Technology. James graduated from Gordon College with a Bachelors in Physics, and is now working on modeling the processing of materials using mesoscale particle-based approaches.

Enhanced Compost Rate and Simultaneous Toughening by Multifunctional Additives in Poly(lactic Acid)

Summary

A particle additive is reported that simultaneously improves ductility and biodegradation behavior of poly(lactic acid) (PLA). Our approach explores the use of encapsulation technology to create degradation-promoting additives while limiting any breakdown of the matrix during melt extrusion and service life. In addition to promoting biodegradation such encapsulated particles are designed to enhance toughness of the matrix. Such dual use particles have the potential to broaden the uses of PLA. In this work, particle properties are examined and the accompanying tensile behavior and compostability of the composite investigated. Particles were dispersed within the PLA matrix by extrusion to 3D printer filament. Elongation at break was improved over neat PLA with limited loss of yield strength. Degradation rate in compost is accelerated and decoupled from environmental conditions by embedding a degradant material into the PLA matrix itself, aided by encapsulation technology that isolates and protects the degradant. The additive has been found to improve mechanical properties while accelerating the biodegradation of parts produced by extrusion-based methods.

About the Speaker

Raymond A. Pearson received a B.S. degree in chemistry from the University of New Hampshire, Durham, in 1980 and a Ph.D. degree in materials science and engineering from the University of Michigan, Ann Arbor, in 1990.

Dr. Pearson joined the Materials Science and Engineering Department at Lehigh University, Bethlehem, PA in August 1990. Prior to graduate school, he had worked for seven years with General Electric Company: from 1980-1984 as an associate staff member at GE's Corporate Research and Development Center in Schenectady, New York and from 1984-1987 as a materials specialist at GE Plastics Europe’s Product Technology Center in Bergen op Zoom, the Netherlands. Ray is currently a Professor of materials science and engineering and the Director of the Polymer Science and Engineering graduate program. His research interests include all aspects of processing, deformation, yield, and fracture of polymers as well as adhesion and interfacial issues in microsystems packaging. He is an Executive Board Member (Vice President Publications) of the Society of Plastics Engineers and is a member of the Board of Directors for SPE’s technical interest group on Additive Manufacturing, Palisades Mid-Atlantic Section and Polymer Modifiers and Additives Division.

Bond Strength of Solvent-Bonded PVC Tubing to Polycarbonate Luer Connectors

Summary

This study describes a method to measure the bond strength of PVC tubing that has been solvent bonded to polycarbonate Luer connectors. Various grades of polycarbonate were joined with flexible polyvinylchloride (PVC) tubing based on either di(2-ethylhexyl) phthalate (DEHP) or an alternative plasticizer. Solvents studied in this work included Dichloromethane (DCM), Cyclohexanone (CHX) and Methyl Ethyl Ketone (MEK). Relatively consistent bond strengths were observed with CHX between ambient temperature drying from 24hr to 72hr. Oven drying at 40°C improved bond strengths compared to ambient conditions. A mixture of CHX and MEK gave good bond strengths and lessened chemical attack on the tubing. Results with DCM showed greater variability, believed to be attributed to its propensity to evaporate during the brief time between immersion of the tubing and joining it to a Luer connector.

About the Speaker

Sarah Fisher is currently an R&D Scientist at Covestro, LLC. She received a Bachelor’s in Chemical Engineering from the University of Pittsburgh and a Bachelor’s from Saint Vincent College in Math and Engineering.

Improving the Ductility of rPET Plastic Lumber

Summary

DOD Forward Operating Bases have solid waste issues similar to a small city. PET is one of the major plastic waste streams which comes mainly from beverage containers. One approach to utilizing this waste stream is to convert it into plastic lumber for on-base use. A 2020 ANTEC paper described the initial research toward this goal with successful production of plastic lumber using flow molding. The resulting product was brittle however, and the current efforts are focused on improving the ductility of this product. This paper will described several additives used to improve the ductility of rPET plastic lumber.

About the Speaker

Mr. Heggs has been employed by Engineering Mechanics Corporation of Columbus for the last 2 years working on recycling of PET for the Department of Defense. Prior to joining EMC2 Mr. Heggs was the owner and founder of his consulting firm The Material Solution LLC. For the majority of his career Mr. Heggs worked for Battelle Memorial Institute the world's largest independent contract research organization in a variety of roles. These roles have included individual researcher, group leader, department manager, and business development and marketing. Mr. Heggs is a recognized expert in polymer processing and he has experience in all facets of polymer processing including injection molding, extrusion, thermoforming, compression molding, casting and additive manufacturing. Mr. Heggs has over 20 publications including two book chapters.

Education

• B.S. Chemistry, Miami University (Cum Laude)
• M.S. Chemistry, Cornell University

Qualifications

Mr. Heggs has been employed by Engineering Mechanics Corporation of Columbus for the last 2 years working on recycling of PET for the Department of Defense. Prior to joining EMC2 Mr. Heggs was the owner and founder of his consulting firm The Material Solution LLC. For the majority of his career Mr. Heggs worked for Battelle Memorial Institute the world’s largest independent contract research organization in a variety of roles. These roles have included individual researcher, group leader, department manager, and business development and marketing. Mr. Heggs is a recognized expert in polymer processing and he has experience in all facets of polymer processing including injection molding, extrusion, thermoforming, compression molding, casting and additive manufacturing. Mr. Heggs has over 20 publications including two book chapters,

Automated Optimization of a Block-Head-Mixer with an Innovative Algorithm

Summary

CFD-Simulations are a common tool to design and optimize mixing elements. The manual evaluation and experience-based derivation of an optimized geometry is still an iterative process which is time consuming. In this paper an automated algorithm is developed and tested for a mainly distributive Block-Head-Mixer. To automatically evaluate the flow field of each geometry variant, quality criteria are introduced which enable the assessment of the mixing capability. The investigation showed that the quality criteria are suitable to evaluate the flow field and an optimized candidate compared to a starting geometry could be found automatically.

About the Speaker

Felix Vorjohann studied industrial engineering at the University of Duisburg-Essen, Germany, with mechanical engineering and management as his field of study. Conferred the Master of Science in September 2021, he is now a research assistant at the Institute of Product Engineering (ipe) at the chair of Engineering Design and Plastics Machinery (KKM), University of Duisburg-Essen.

Recycled Carpet-Reinforced Composites From Polyester Carpet and Recycled PET Resin

Summary

A method was developed for fabricating recycled composites from post-consumer polyethylene terephthalate (PET) carpets and recycled PET resins. Compression molding of the components under different pressures, temperatures, and compositions was performed. Preliminary molding conditions were arrived at based on analyzing the differential scanning calorimetry (DSC), thermal gravimetric analysis (TGA), and melt viscosity data for different raw material combinations. Molding factors were screened to define applicable ranges for each parameter. The effects of configuration and composition of components, temperature, molding time, and pressure were considered in the screening process. Mechanical properties of composites were determined by 3-point flexural (according to ASTM D790) and creep tests. The molded materials showed acceptable mechanical strength and modulus values required for structural applications.

About the Speaker

Mohamadreza Youssefi Azarfam (call him Reza Azarfam if you will), Ph.D. Candidate at Oklahoma State University, has research interests in material science and polymer chemistry. He was born in Tabriz, Iran, and received his Bachelor’s in Chemistry from the University of Tabriz, Iran, and his Master’s in Polymer Chemistry from the Research Institute of Petroleum Industry, Tehran, Iran. His work has recently focused on making useful polymer composites for recycling purposes and studying their chemical and mechanical properties. He also studies the thermal behavior of polymers at interfaces. He has published a few papers in different fields of polymer science including the kinetics of polymerization, polymer nanocomposites, compression molding, tissue engineering, and 3D printing.

LAOS and Fourier transform rheology of epoxidized soybean oil/nanoclay colloid treated by ultrasound

Summary

Large amplitude oscillatory shear (LAOS) studies were carried out on untreated and ultrasonically-treated ESO/nanoclay 30B colloids obtained by means of an ultrasonically assisted twin-screw extruder (TSE) at 100 and 400 rpm and ultrasonic amplitudes of 5, 10 and 13µm. Obtained results were used to perform Fourier transform. Waveform, 3D stress response, elastic and viscous Lissajous curves show significant differences between the untreated colloids and colloids treated at 10 and 13µm. Values of G_1^' and G_1^' of colloids are increased with increase of ultrasonic amplitude, as the result of better nanoclay dispersion at higher ultrasonic amplitudes. A higher screw rotation speed also improved nanoclay dispersion for untreated colloid and colloid treated at 5µm. However, for colloid treated at 10 and 13µm, a lower screw rotation speed resulted in a better dispersion. This is due to less asymmetric bubble collapse and more jet flow in ultrasonic zone at lower screw speed, which promotes dispersion. Colloids treated at 10 and 13µm showed yielding and then a non-linearity at a higher strain amplitude compared with untreated colloids. The values of G_M^' and η_L^' of colloids calculated from intracycle data exhibited the densification and filler network breakup much more observable than those seen on values of G_1^' and G_1^'. This means G_M^' and η_L^' are more suitable for description of colloids with the two-step yielding behavior. Parameters S and T calculated based on intracycle data showed enormous differences in the strain hardening/softening and shear thickening/thinning behaviors between the untreated colloid and the colloids treated at 10 and 13µm.

About the Speaker

Dr. Avraam I. Isayev is Distinguished Professor Emeritus of Polymer Engineering at University of Akron. He received his Ph.D. in Polymer Science and Engineering, Institute of Petrochemical Synthesis of USSR Academy of Sciences, Moscow; M.Sc. in Applied Mathematics, Institute of Electronic Machine Building, Moscow; M.Sc.in Chemical Engineering, Azerbaijan Institute of Oil and Chemistry, Baku. Prior to joining the University in 1983, Isayev conducted research at Cornell University, Technion and USSR Academy of Sciences. His research interests focus in polymer and composite processing, process modeling, rheo-optics, rheology and constitutive equations of polymers, oil products and disperse systems; the injection, co-injection, transfer, compression and gas-assisted injection molding; processing of self-reinforced or in-situ composites based on blends of flexible and thermotropic liquid crystalline polymers; decrosslinking of thermosets, devulcanization of rubbers and in-situ copolymer formation in immiscible blends with the aid of ultrasonic waves; high temperature and high performance composites and nanocomposites. Isayev has co-authored 3 editions of 1 monograph on rheology, edited or co-edited 8 books, published 273 papers in journals, 36 chapters in books, 8 papers in encyclopedias and 30 patents. He advised 49 PhD, 42 MS students and 31 postdocs and visiting scientists. Isayev is the recipient of the Young Scientist Award (Moscow), OMNOVA Solutions Signature University Award, Melvin Mooney Distinguished Technology Award and Stafford Whitby Award for Distinguished Teaching and Research both from Rubber Division of ACS, Silver Medal from Institute of Materials (London), Vinogradov Prize from Society of Rheology (Moscow), NorTech Award from Crane Publishers, James L. White Award of PPS and SPE International Award. He is SPE and PPS Fellow. Elected to New York Academy of Sciences in 1994 and European Union Academy of Sciences in 2017.

Development of an Inline-Measurement System of the Surface Temperature of Square Hollow Profiles

Summary

In polymer extrusion, the die temperature is normally set to the recommended temperature in order to reach a homogeneous melt. Nevertheless, the measurement of the melt and surface temperature of the product leaving the die is not state of the art due to the difficulty of an inline-measurement. As a consequence, the product temperature leaving the die is assumed as the set die temperature. Therefore, this article aims to engineer an inline-measurement system of the surface temperature of square hollow profiles immediately after leaving the die. First, two objective quality criteria to define the thermal melt homogeneity, named weighted melt temperature and radial temperature, are introduced. After that, experimental investigations are carried out for two different types of polyolefin polymers with the variation of several process parameters such as the screw speed and the die temperature. In order not to distort the product, the developed construction is based on a contactless measurement system using infrared pyrometers to measure the average surface temperature on each side of the profile. Afterall, rules of behavior are derived from the process and correlations between the investigated process parameters and the melt quality as well as the surface temperature are identified.

About the Speaker

Jonas Köllermeier studied mechanical engineering with the focus on plastic technologies at Paderborn University, Germany.

He achieved the degree Master of Science in 2019 and has been working as a research assistant at the chair of Kunststofftechnik Paderborn at Paderborn University since April 2019. His research topic is the development of simulation based assistant systems for extrusion processes.

Long Term Aging Characteristics of Post-Consumer Recycled (PCR) Polycarbonates

Summary

In this paper, the tensile properties of indoor and outdoor post-consumer recycled (PCR) polycarbonates (PC) have been compared with virgin PC at various aging conditions. 50% recycled PCs showed comparable tensile strength at breakage (~70 MPa) and maximum strain (~190 - 200%) before aging, when compared to virgin PC of same MFR of ~10 g/10 min. Three different high temperature and high humidity aging conditions were investigated: 40oC 90% RH, 60oC 90% RH, and 85oC 85% RH for up to 500 hours. Strength at breakage was found to decrease as the aging stress or aging time (with the same aging condition) was increased. Both the indoor resins were comparable in strength up to 60oC 90% RH. But in 85oC 85% RH both showed significant drop in strength. On the other hand, outdoor PCR resin showed much better performance (only ~12% degradation) in 85oC 85% RH compared to other two indoor resins (25 - 40% degradation). Outdoor UV aging characteristics were also compared between 0%, 50% and 75% PCR and degradation up to 600 hours were found to be within 5%.

About the Speaker

Rashed Islam is a HW Reliability Manager at Lyft Transit Bikes and Scooters (TBS). His group is responsible for the product reliability for the micro mobility devices (Bikes, Scooters, stations etc.). Previously Rashed was the Technical Lead Manager at Google Devices and Services. He was also leading the Sustainable Materials Reliability efforts for Google’s consumer HW. He has successfully launched several generations of Nest Thermostats which have a very high customer satisfaction and helped the design team to adapt recycled polycarbonates in different consumer devices. Rashed has more than 15 years of industry experience in reliability engineering, failure analysis, and materials development (recycled plastics, Pb free solder, piezoelectric, and magnetoelectric materials). Before Google, Rashed worked on E-reader and Tablets (at Amazon), LEDs (at Philips) and Energy Harvesters and Dielectric Antennas (at Eoplex). Rashed has a PhD in Materials Science and Engineering and has published more than 50 Journal/Conference publications and Book chapters. He has also authored 2 US patents.

Complex Viscosity of Star-Branched Macromolecules from Analytical General Rigid Bead-Rod Theory

Summary

The complex viscosity of planar star-branched polymers has been derived from general rigid bead-rod theory, but only for singly-beaded arms. Here, we explore the respective roles of branch functionality, arm length and non-planar arrangements, analytically from general rigid bead-rod theory. For non-planar, we include polyhedral, both regular and irregular. Further, for all structures, we compare with and without the central bead. We fit the theory to complex viscosity measurements on polybutadiene solutions, one quadrafunctional star-branched, the other unbranched, of the same molecular weight (M_w=200,000 g/gmol). We learn that when general rigid bead-rod theory is applied to quadrafunctional polybutadiene, a slightly irregular center-beaded tetrahedron of interior angle 13° is required (with 1,360,000 g/gmol per bead) to describe its complex viscosity behaviour.

About the Speaker

I am a first-year PhD student at Queen's University in Kingston, ON, Canada, studying under Dr. Giacomin in the Polymers Research Group. Our group studies theoretical rheology, specifically the effect of macromolecular branching on rheological properties. I have 4 published papers and 2 additional conference proceedings.

Effect of Slip Additive on Mechanical Recycling of HDPE

Summary

In this study, the effect of an amide-based slip additive was evaluated on injection moulded HDPE specimens, subjected to three loop of mechanical recycling streams. The results were compared with control HDPE (no additives) on each recycling loop. Results showed that after 3 mechanical recycling loops the inclusion of Incroslipâ„¢ C enhanced flow by doubling the MFR of the rHDPE whilst not affecting further the tensile and impact properties. In fact, rHDPE plus additive maintained its ductility (strain at break) compared to control rHDPE, which became more brittle, something attributed to cross-linking. Finally, the inclusion of additive improved the aesthetics of the recyclate.

About the Speaker

Emile Homsi is the Global R&D Manager for the Smart Materials NA division for Croda Inc. Dr. Homsi has spent the bulk of his career in strategic leadership of global application, product, innovation and business development programs in the High-Performance Engineered Polymer Industry as well as the commodity Polymers Industry for major Chemical Companies, such as Honeywell, BASF, DSM and Sabic. He was responsible to drive the execution to develop core competencies, acquiring business and devising short, midterm and long-term strategies for growth. Dr. Homsi has been has built high performance teams responsible for many innovations. Dr. Homsi has a Doctorate in Mechanical Engineering; a Masters in Technology Management; and several other Degrees.

Development of a Micro-Capillary Rheometer for High Solids Content Rheology

Summary

Rheological testing of new material formulations can require significant quantities, specifically when considering the development of new chemistries at the laboratory scale. In order to minimize the quantity of material required for evaluation, we are developing approaches suitable for characterization of high solids content formulations using micro-capillary rheometry. The goal of this investigation is to design and produce a micro-capillary rheometer capable of characterizing basic rheological properties, such as viscosity and shear-thinning behavior, while requiring the least amount of sample possible. In our current design, we implement a micro-dispensing approach combined with calibrated force transducers. With this approach we can further elucidate an understanding of the differences between typical capillary rheometry and behavior at reduced dimension flow fields. Issues such as pressure relaxation and free volume compaction can therefore be studied through readily modified geometries and testing rates. This design will lead to a better understanding of micro-capillary rheometer design and enable a unique approach for rheology measurements for new chemistries and formulations, including high solids content formulations (up to 60+ vol %). Additionally, this framework will facilitate the study of a variety of flow geometries applicable to a wide range of applications including precision dispensing of adhesives and sealants, and direct ink write additive manufacturing.

About the Speaker

TBA

Effect of Talc and Carbobimide on the Hydrolytic Resistance of a Poly(L-Lactic Acid) Compound

Summary

In this work we examine the influence of talc and a polymeric carbodiimide on the hydrolytic degradation resistance of a commercially available Poly(L-Lactic acid) PLLA. Here, polymer blends containing 0-4wt% talc, a crystal nucleating agent and 0-1 wt% of a polymeric carbodiimide (CDI), an anti-hydrolysis agent, were melt blended and compression molded into plaques. Samples were then submerged in a phosphate buffer solution (PBS) at 50°C for up to 60 days. Results indicate that the presence of talc as the sole ingredient in the formulation increases the crystallization rate and this translates to an increase in the degree of crystallinity of compression molded plaques and a modest improvement in hydrolytic degradation resistance as compared to unfilled PLLA. The presence of CDI retards PLLA crystallization. In spite of this, compounds containing CDI exhibited much greater hydrolytic degradation resistance than PLA with the effect being more pronounced with increasing CDI concentration. Under DSC conditions, the addition of 1wt% talc to CDI containing compounds improved the non-isothermal crystallization rate at 5°C/min but this effect diminished as cooling rate increased and this explains the low crystallinity of compression molded samples. However, compounds containing both talc and CDI showed an improved hydrolysis resistance as compared to compounds containing only CDI implying that talc's role in reducing the rate of hydrolysis is caused by the hydrophobic characteristic of the material. It is envisioned that this work will help pave the way for the usage of PLA in durable applications where long-term resistance to humidity is anticipated.

About the Speaker

Effect of Plasma Treatment on Degration of Biodegradable Mulch Film

Summary

Mulch films modify soil conditions thus improving crop output, hence are widely used across the world. Traditional PE (polyethylene) films do not degrade and must be disposed of afterwards. Biodegradable mulch films (BMFs) provide a much better alternative and are meant to be tilled with the soil after harvest. But most BMFs degrade slowly and accumulate in soil, harming the soil productivity. In this investigation we evaluate the effect of gliding arc plasma treatment on the behavior of a commercially available biodegradable mulch film based on polybutylene adipate co-terephthalate (PBAT) and polylactic acid (PLA). Following plasma treatment an initial increase in the hydrophilicity of the films is observed and this is attributed to an increase in oxygen containing species on the surface. Moreover, hydrophobic recovery is slow as indicated by contact angle measurements taken over a 30-day time. Thermal analysis results indicate no significant difference indicating that treatment is confined primarily to the surface. A treated film showed enhanced disintegration as compared to an untreated film following 65 days of composting in an aerated static pile compost. These results indicate that plasma treatment may aid the biodegradation of plastic mulch films and therefore eliminate their accumulation in soil.

About the Speaker

Evaluation of Component Specifications of Large-Format Plastic Products Though the Use of Machine Learning Methods

Summary

This conference paper presents the investigations, results and findings from the research project "Tool-integrated assistance system for production control of highly complex and demanding component specifications" (acronym in German WASABI). The project investigates the possible use of sensor technology in combination with machine learning methods for the prediction of quality-determining component features on large-format plastic products. Furthermore, the information obtained will be used to propose target-oriented recommendations for action based on the predicted feature characteristics. An outer skin component (bumper) from the automotive sector was defined as the reference product for the investigations into the prediction possibilities of demanding component specifications. The injection molding tool required for production was designed as part of the project work and equipped with a variety of different sensor types (including pressure, melt contact, displacement measurement). The recording of the measurement signals is realized by a self-developed hardware system concept. The aim of the research is to predict various quality-determining characteristics from the fields of geometry (including total lengh) and surface (including sink marks). In the course of the project, extensive tests were carried out to generate a meaningful database. Through analysis and evaluation, it was possible to define the positions and number of sensors that provide a high level of information. Ultimately, three different approaches of machine learning methods could be learned for the prediction of component qualities and the prediction of corrective actions. These structures could be verified in laboratory environment by appropriate test data sets.

About the Speaker

Education

2013 - 2017: University of Applied Sciences Schmalkalden
Field of study: Mechanical Engineering
Degree: Bachelor of Engineering

2017 - 2018: University of Applied Sciences Schmalkalden
Field of study: Applied Plastics Engineering
Degree: Master of Engineering

Professional Career

08/2008 - 02/2012: Training as a cutting machine operator for turning and grinding techniques, Reinhardt Ventile GmbH, Fambach

02/2012 - 08/2012: Employment as Cutting machine operator, Reinhardt Ventile GmbH, Fambach

03/2018 - 09/2018: Employment as Design engineer, E-proPlast GmbH, Schmalkalden

since 12/2018: Research assistant at the University of Applied Sciences Schmalkalden, Applied Plastics Technology

Pressure-Controlled Injection Molding of Recycled Polyolefins

Summary

The importance of utilizing recycled materials to manufacture plastic products has been a topic of great interest due to the environmental repercussions. Processing issues arise from the usage of these resins due to the variation in their molecular weight and rheology. In this work, pressure-controlled injection molding is evaluated and compared against conventional velocity-controlled injection molding. The effects of injection velocity, mold temperature, and pressure on part shrinkage and mechanical properties of injection molded parts fabricated with post-consumer film-grade polyethylene were evaluated. The experimental results show that the different processing techniques significantly affect the mechanical properties and part shrinkage for both materials. Additionally, different levels of injection pressure and velocity significantly affect the shrinkage of the plastic parts. Moreover, it was seen that parts fabricated using pressure-controlled injection molding had preferable overall quality.

About the Speaker

Injection Molding of Microporous Ultra-High Molecular Weight Polyethylene

Summary

Microporous ultra-high molecular weight polyethylene (UHMWPE) parts were produced by microcellular injection molding (MIM) technology, which enabled higher production efficiency and lower part cost compared to the traditional powder sintering method. The microstructure could be tuned by adjusting the shot size to produce either sandwiched solid-skin – porous-core – solid-skin parts or open porous parts. The pore morphology, average pore size, pore size distribution, and pore density were characterized, and the water contact angle (WCA) and degree of oil-water separation were determined. The part weight reduction of open-porous UHMWPE and sandwiched UHMWPE parts were 16.5 wt% and 11.8 wt%, respectively. The WCA results showed that the porous surface transformed molded UHMWPE samples from being hydrophilic (34.5°) to hydrophobic (124.6°). Furthermore, the open-porous structure exhibited good oil-water separation capacity. Tensile tests were carried out to study the effect of morphology on the mechanical performances of the molded UHMWPE parts. The characterization shows that a possible application for the sandwiched UHMWPE parts could be as a bone replacement material because of its high mechanical performance, and an application for the open-porous UHMWPE is as a functional filter material due to the fine pore size and high pore density.

About the Speaker

Investigation of Orotic Acid Effects on The Crystallinity Development of Poly-Lactic Acid

Summary

This research investigated the effect of the addition of Orotic Acid (OA) on the crystallization kinetics of Poly-lactic Acid (PLA) in quiescent and non-quiescent conditions. A differential scanning calorimetry (DSC) study was used to investigate and understand the effect of the addition of orotic acid on 2500 HP PLA under quiescent conditions. DSC technique was utilized to capture the crystallinity, melting point, and other thermal parameters of PLA-OA blends. Conventional injection molding (CIM) was used to investigate the influence of adding OA into PLA under non-quiescent conditions. Two concentrations of orotic acid, 0.3 wt% and 0.7wt% were mixed with neat PLA and then investigated. It was observed that the 0.3 wt.% orotic acid provided significant improvement in crystallization kinetics by increasing the crystallinity and reducing the incubation time. Both blends under quiescent conditions showed almost the same crystallinity in which the maximum crystallinity that was observed was around 63% in the blend of the PLA/0.7OA at 85°C. For 2500HP PLA, Orotic acid (OA) showed to be an effective nucleating agent. A small amount (0.3 wt%) was sufficient to achieve 61% of crystallinity in injection molding at 80°C mold temperature.

About the Speaker

John P. Coulter is a Professor in the Department of Mechanical Engineering and Mechanics at Lehigh University. On the administrative front he has served as the Senior Associate Dean for Research for the P.C. Rossin College of Engineering and Applied Science since 2016 and prior to that been an Associate Dean responsible for research, graduate studies, and engineering college operations since 2002. On two separate occasions, the latest taking place from 2015 through 2016, Dr. Coulter served as the Interim Dean of the College of Engineering and Applied Science at Lehigh. In that capacity he was responsible for the operation, coordination, financial management, advancement, and oversight of all engineering related activities at the University. He holds Bachelor of Science and Master of Science degrees in mechanical and aerospace engineering from the University of Delaware, and completed his doctoral studies in mechanical engineering at Delaware in 1987. His graduate studies were supported by a prestigious and nationally competitive DoD Fellowship awarded through the Office of Naval Research.

Coulter has 32 years of teaching and research experience at Lehigh, as well as several years of industrial experience with Lord Corporation, a multi-national company specializing in materials and devices for vibration and acoustic control. During his time at Lehigh, he has taught several thousand undergraduate students, mentored 25 doctoral students and 65 master’s students, and won several awards for curriculum innovation that incorporates K-12 students from diverse backgrounds. His accomplishments at Lehigh have been recognized through continuous federal, state, and industrial research support as well as numerous awards for teaching and research including a prestigious NSF National Young Investigator (i.e. CAREER) award, Lehigh’s first-ever NSF Presidential Faculty Fellow (i.e. PECASE) award, a Future Technology Award from the Society of Plastics Engineers, and two Innovative Curriculum Awards from the American Society of Mechanical Engineers. Professor Coulter is also a Fellow of the American Society of Mechanical Engineers.

Investigating the Optical and Mechanical Properties of Stimuli Responsive Electrosterically Stabilized Nanocellulose Crystals in Thermoplastic Polyurethane

Summary

A new type of nanocellulose crystal (CNC) has been gaining interest for its unique morphology combined with its as-produced carboxylate functionality: electrosterically stabilized nanocrystalline cellulose (ENCC). When ENCCs are added to thermoplastic polyurethane (TPU) composites and submerged in water they display a unique increase in opacity. Using UV-VIS and DMA, the optical and mechanical properties of these composites can be studied at differing ENCC concentrations.

About the Speaker

TBA

Production of Flexible Thermally Conductive Thermoplastic Pipes by Orientation of Filler Particles

Summary

Pipes for heat exchanger systems are usually made of metals to achieve a high level of energy transfer. Polymers, in comparison, save weight and costs and are suitable for use in corrosive and chemically aggressive environments. However, for many applications the comparatively low thermal conductivity of polymers is a disadvantage. To overcome this, polymers are usually mixed with high amounts of fillers, which transport the heat through the pipe wall. But the use of high filler ratios influences the mechanical properties of the pipe significantly. The aim of this paper is to develop a concept for a pipe extrusion die which aligns the filler particles in radial direction, so that the anisotropic material properties of the compound can be utilized and thus the amount of filler can be reduced. Consequently, the flexible material properties can be maintained as far as possible. Several die concepts are presented and their influence on the thermal and mechanical properties of the pipe are compared.

About the Speaker

Characterization of Vibration Welded Pine, Maple and Bamboo

Summary

This study investigates the factors affecting the welding of pine, maple, and bamboo pulpboard. This research used a Branson Mini II vibration welder traditionally used for welding plastics. The effects of weld pressure, amplitude, and weld time were varied to determine their effects on lap-shear weld strength. Strength testing was performed with a universal testing machine. The morphology of the weld zone was also analyzed to gain insight into the welding mechanics. The highest strength of pine samples was 8.4 MPa, while maple was approximately 35% stronger and had a smaller standard error. It was observed that bamboo pulp board weld strength was primarily dependent on weld pressure. Also, pulpboard seemed to weld in a similar fashion to wood.

About the Speaker

Characterization of Vibration Welded Pine, Maple and Bamboo

Summary

The viscoelastic properties of carbon fiber reinforced thermoset composites are of utmost importance during processing such materials using composite forming. The quality of the manufactured parts is largely dependent on intelligent process parameter selection based on the viscoelastic and flow properties of the polymer resin. Viscoelastic properties such as the complex viscosity, storage modulus, loss modulus, and loss tangent are used to determine the critical transition events (such as gelation) during curing. An understanding of the changes in viscoelastic properties as a function of processing temperature and degree of cure provides insight to establish a suitable processing range for compression forming of prepreg systems. However, tracking viscoelastic properties as a function of cure during the forming process is a challenging task. In this current work, we have investigated the effect of sample size and adhesive type on the rheological properties of a commercially available carbon fiber prepreg material. Specifically, determining the linear viscoelastic region (LVE) as a function of sample configuration and different adhesive chemistries were explored. The results suggest that the square-shaped sample geometries coupled with cyanoacrylate based adhesive are optimum for conducting rheological characterization on the carbon fiber prepreg system.

About the Speaker

Arit Das is a 5th year graduate student working in the Polymer Composite and Materials Laboratory under the supervision of Dr. Michael J. Bortner in the Department of Chemical Engineering at Virginia Tech (VT). He is currently involved with research on additive manufacturing of semicrystalline polymers, thermoset composite processing, rheology of polymer blends for 3D printing, and environmental implications of 3D printed parts. Arit received the International Research Experience for Students fellowship (2018-19) from the College of Engineering at VT to conduct collaborative research at the University of Nottingham. During his time at VT, he has won multiple awards including the Adhesive Manufacturers Association Adhesive and Sealant Science scholarship (2019), David Jackson/Bostik Excellence Award (2020), and John G. Dillard Travel Award (2021) from the Macromolecules Innovation Institute at VT. He was one of the recipients of the prestigious Peebles Award (2021) at the 44th Annual Meeting of the Adhesion Society. He has also received the TRFA Excellence in Thermoset Polymer Research Award (Invited Poster Presenters, 2019), AIChE Next-Gen Manufacturing Travel Award (2019), ACS I&EC Division Graduate Student Award (2020), and AIChE Excellence in Graduate Student Research Award (2021). Prior to joining VT, Arit received his Bachelors in Chemical Engineering from Jadavpur University in India.

Production of Flexible Thermally Conductive Thermoplastic Pipes by Orientation of Filler Particles

Summary

In this study, PET was combined with a latent metal oxide reagent, CaO, which allowed the PET to hydrolyze when submerged in water, breaking down the polymer chain and forming calcium terephthalate as a nontoxic byproduct. PET/CaO composites were mixed at 10, 20, and 30 wt% CaO, and 0.001” thick films were prepared by compression molding. These films were degraded in water at 90 degC for varying amounts of time. Puncture testing, optical microscopy, FTIR, and TGA were performed to probe the degradation of the material and verify that it was producing the products that were expected from the reaction. The PET/CaO composites were shown to be degradable in water, with a significant loss in mechanical properties after only an hour. The rate of degradation was strongly dependent on the concentration of CaO, with significantly faster degradation at higher concentrations.

About the Speaker

Natalie is a second-year Ph.D. student in chemical and biomolecular engineering at the Georgia Institute of Technology, where she researches degradable polymers for packaging applications.

Mechanical Recycling of Single-Use Polyethylene Into Materials With Variable Properties

Summary

The post-consumer single-use polyethylene-based plastic bags supplied by the supermarket grocery stores, are converted into new materials with improved mechanical properties using a thermomechanical recycling process. The low-density polyethylene (LDPE) sourced from waste plastic bags, is injected into a high shear internal mixer and compounded with the additives such as acrylonitrile-butadiene copolymer or nitrile rubber (up to 10 wt%) and also treated with an organic peroxide curing agent. The resultant materials exhibit high ductility and elasticity, with a maximum tensile strength of 20.3 MPa, stiffness of 1262 MPa, elongation of approximately 500%, and impact strength of 62 kJ/m2 depending on materials compositions. These mechanical properties are profoundly higher than those of neat recycled LDPE. It is observed that the post-consumer plastics contain a significantly high amount of calcium mineral of approximately 30 wt% (13 vol %), which plays a key role in improving mechanical properties during high shear blending with additives such as nitrile rubber. The melt-rheological characteristics such as complex viscosity and storage modulus of the materials are analyzed to evaluate the thermal recyclability and thermoplastic nature of the materials.

About the Speaker

Dr. Arun Ghosh is an Assistant Professor at Troy University in Alabama. Currently, he is a leading researcher at the Center for Materials & Manufacturing Sciences at Troy University. His current research focuses on polymer compounding and recycling. He obtained his Ph.D. in polymer/rubber technology from the Indian Institute of Technology Kharagpur in 2003. Before joining Troy University, Arun worked as a scientist and post-doctoral fellow in a number of organizations such as the University of Tennessee Knoxville, Case Western Reserve University in Ohio, the University of Toronto in Canada, and AgResearch Ltd in New Zealand. He was a Visiting Scientist at the Zhejiang University, China under the 2011 New Zealand-China Scientist Exchange Programme. His academic and research expertise includes plastic recycling, biopolymer and bio-composites, natural fiber composites, proteins and allied materials, polymer nanocomposites, polymer adhesion and coating technology, and rubber technology. He has published over 30 research articles in peer-reviewed journals as a key author and prepared numerous technical reports for various industries.

Biobased and Recyclable Polysulfones Using Imine Chemistry

Summary

An alternative to bisphenol A was used to synthesize polysulfones that are chemically recyclable. Vanillin was reacted with 4-aminophenol to generate a diphenol with an imine The synthesis of PSs is done by means of polycondensation of dibasic phenols with sulfur-containing aryl halides by the mechanism of nucleophilic substitution. The lignin based diphenol replaces traditionally used bisphenols (a xenoestrogen) and is the site for recycling the polymer. The polymerization is studied under various conditions (temperature, time, monomer ratio) for best properties and product purity. The polymer structure was confirmed via NMR and its thermal properties studied using DSC and TGA (Tg~122°C, Td5~270°C, Td10~400°C, Tprocess~180). The stability of the imine bond was studied under the reaction conditions for reactant stability.

About the Speaker

Vitasta Jain is a graduate student in Material Science and Engineering at Clemson University. Vitasta works with Dr. Srikanth Pilla on biobased polymers and chemical recycling.

Agility™ Performance LDPE for Demanding Applications and Sustainability

Summary

A specific class of high throughput AGILITY™ Performance LDPE's will be discussed focusing on highly differentiated, super-fractional melt index low density polyethylene (LDPE's) that improve manufacturing efficiencies and enhance the performance and aesthetics of sustainable flexible packaging. These high-performance LDPE's expand blown film capabilities by increasing output and improving performance in applications such as agricultural, greenhouse, collation shrink, lamination films, and storage container liners. Converters have demonstrated these resins provide a more stable blown film bubble especially with larger-sized bubbles, thereby reducing waste, providing a more consistent product, as well as the ability to downgauge to achieve sustainability initiatives. AGILITY™ Performance LDPE is often paired with other polyethylene and functionalized resins, allowing for 100% polyethylene films and easy recyclability. In summary, AGILITY™ Performance LDPE is a revolutionary product family, enabling improved processing efficiency, abuse, and aesthetic properties in a broad range of applications benefiting consumers and society.

About the Speaker

Andrew Heitsch is a Senior Research Scientist in the Product Development R&D division of the Packaging & Specialty Plastics (P&SP) business in The Dow Chemical Company. Andrew is responsible for R&D projects related to product development and polyethylene production. His current focus is on gas phase and high pressure technologies to create unique polyethylene resins with improved performance for advantaged products.

Andrew began his career at The Dow Chemical Company in 2010 in the Inorganic Materials & Heterogeneous Catalysis division in the Core Research & Development unit in Midland, MI. In 2017 he transferred to the P&SP business in Lake Jackson, TX. Over his career Andrew has led and contributed to projects across the fields of electronic materials, catalysis, coatings, chemical feedstocks, sustainability, and polyethylene resin developments. He is involved with various industrial and academic collaborations, mentorship programs such as UT-Austin MRSEC, and is a recruiter for The Dow Chemical Company.

Andrew graduated with a B.S. in Chemical Engineering from the University of Florida in 2005 and a Ph.D in Chemical Engineering from The University of Texas 2010. He is six sigma green belt certified, authored 22 publications, 70+ internal reports, and 18 patents/priority patent applications.

Compressibility in Fused Deposition Modeling

Summary

Fused deposition modeling (FDMTM), also referred to as fused filament fabrication (FFF) is an additive manufacturing technique in which extruded material is deposited into roads and layers to form complex products. This paper provides a physics-based model for predicting and controlling the effect of compressibility in material extrusion including elasticity in the driven filament and compression of the melt in the hot end. The model is validated with a test part embodying a full factorial design of experiments with three print speeds. The model is used for control and shows elimination of 50% of the associated road width variance due to compressibility, thereby enabling higher quality levels even at higher print speeds.

About the Speaker

David O. Kazmer was born in Cleveland, Ohio and received his undergraduate Mechanical Engineering degree from Cornell University and doctorate from Stanford University's Design Division. He has been both an engineer and manager in industry. He is a fellow of ASME and SPE. He is now teaching and researching in the areas of plastics product design, machine design, and manufacturing processes.

Thermal Degradation Mechanism of Polylactic Acid

Sustainability/Recycling

Summary

Polylactic Acid (PLA) is a degradable polymer and understanding the mechanism of degradation is important. In this work, a reaction model is considered for degradation of PLA. The model is utilized in predicting the progress and mechanism of the PLA degradation. The predictions were analyzed and compared to reported literature.

A reaction scheme is selected from literature to describe thermal degradation of Polylactic Acid. Rate laws and rate constants for the various reactions were either taken from literature, estimated or proposed. Material balance on the reacting species were done to developed a mathematical model for the degradation process. The system of differential equations was solved numerically in MATLAB to predict concentration vs. time plots for various reacting species and also to predict the extent of degradation of PLA with time. The predictions of themodel were compared to experimental data available in reported literature.

Polylactides are highly sensitive to heat that limits their area of applicability. Also, heat may be utilized for quick degradation of PLA if so desired. Among several reasons for poor thermal stability, some are it's zipper like depolymerization, and, intermolecular and intramolecular transesterification resulting in formation of the monomer, oligomeric lactides, lactic acid and acrylic acids. The reaction scheme is able to show generation of these degradation products. The mathematical model in this work is able to predict concentration vs. time plots for low molecular weight PLAs, lactide, lactic acid and acrylic acid.

The concentration of lactide almost linearly increases to about 5 x10-3 mol/cm3 in 28 days of degradation under the conditions considered in the model. Concentrations of lactic acid and acrylic acid increases sharply in the beginning and then their generation slows down after about 15 days. After 30 days, their concentrations asymptotes to about 2 x10-4 mol/cm3. This is because about 90% of the original PLA depolymerizes after 30 days under the conditions of the model. The model also predicts reduction in molecular weight of PLA with time, and also transesterification rate.

The model gives deeper insight into the degradation mechanism, experiments for which are costly and difficult. The model predictions are in agreement with experimental literature data to certain extent.

A new mathematical model is developed in this work that successfully predicts the expected concentration profiles of various degradation end products. A deeper insight into the thermal degradation mechanism of PLA is provided. Such models are useful to industry for predicting shelf-life of PLA and in developing suitable heat stabilizers. Also, this model can be utilized to obtain the key parameters responsible for thermal degradation of PLA.

About the Speaker

Afifa Khan is currently pursuing masters in chemical engineering at UF. She is currently working on surface specificity of sortases and have worked on bioplastics and studied the behavior of thin liquid films on an inclined plane. I am passionate about biomolecular engineering and sustainable energy.

High Shear Viscosity Measurement of a Natural Rubber and Synthetic Rubber Using the Rubber Screw Rheometer

Summary

The shear rate-dependent viscosity of natural rubber and three types of synthetic rubber was measured using the Rubber Screw Rheometer. Viscosity values with Mooney viscometer, which has traditionally measured rubber viscosity, have a high correlation with the values of RSR shear rate 10 [1/s]. Thus the Mooney Viscosity value can be estimated using the RSR shear viscosity measurement. Also, in the case of virgin rubber, the accuracy of the measured value increases when it has a pre-shear history. It was confirmed that the viscosity measurement value was a measurement value having a deviation within +3% when comparing the three times repeated measurements. The measured value was correlated to Mooney Viscosity successfully with a first-order equation.

About the Speaker

Anisotropic Structural Analysis for Injection Molded Fiber Reinforced Thermoplastics

Summary

A seamless modeling framework from injection molding simulation to anisotropic structural analysis is presented. Key features of the framework are anisotropic material modeling and fiber orientation data mapping, aspects that are facilitated by coupling Moldex3D, Digimat, and ANSYS software. The approach is exercised by modeling the mechanical response of injection molded tensile specimens with single and dual gates made of a thermoplastic resin with 20% glass fiber weight fraction. It is reassured that local fiber orientation is crucial for an accurate prediction of the mechanical strength of dual-gated tensile specimens with a weld line. Unlike the isotropic modeling approach, typical features of stress and strain concentrations along the weld line are clearly demonstrated. The capability of the approach is further highlighted by accurately predicting the breakoff torque of a screw head used to adjust the seal compression in cable entry ports of optical closures.

About the Speaker

Development of an Agile, Battlefield Additive Manufacturing Plant for Recycled Polyehtylene Terephthalate (rPET)

Summary

The objective of the overall project is to conduct applied research that will lead to the development of an innovative agile manufacturing plant for onsite fabrication of recycled thermoplastic products at the US military's forward operating bases (FOBs). The proposed manufacturing plant is designed so at to be contained in 20-foot ISO containers for both shipment and operation. A study by the US Department of Defense (DoD) of base camp waste confirmed that the single largest source of waste plastics is Polyethylene Terephthalate (PET) from water and other beverage bottles. The on-going project to convert waste or reclaimed PET (rPET) to useful products is currently being conducted by Emc2 and the US Army Corps of Engineers was initiated by the DoD's Strategic Environmental Research and Development Program (SERDP) in 2018, and is in its final year of completion. Earlier results from this on-going efforts were presented at ANTEC 2020. In other research conducted by DoD [5] it was already confirmed that rPET materials when appropriately processed may be converted to pellets and subsequently to 3D printer filaments for Additive Manufacturing. The material properties of rPET used for 3D printed parts and specimens have been characterized and reported previously.

About the Speaker

Dr. Krishnaswamy received his Ph.D. in Mechanical Engineering from the University of Washington, Seattle, WA. Prior to co-founding Emc2 in 1998, he was a Senior Scientist at Battelle Memorial Institute in the Advanced Materials Department. He has conducted extensive research in both analytical and experimental areas of engineering mechanics and is a renowned expert in the mechanical and failure behavior of plastics, composites, and bio-based materials, especially in structural -bearing applications. He has led both the technology development and worldwide standards activities in the area of recycled plastics and composite lumber. Dr. Krishnaswamy has co-authored over 80 publication in technical journals, conference proceedings and has given numerous invited talks at academic and research institutions. He the holds 6 patents. He is the Principal Investigator of the Department of Defense Strategic Environmental Research and Development Project titled "Development of an Agile, Novel Expeditionary Battlefield Manufacturing Plant Using Recycled and Reclaimed Thermoplastic Materials."

Impact Modification of PLA (Poly Lactic Acid) by Blending Small Amounts of Amorphous PHA (Polyhydroxyalkanoate) Copolymers

Summary

This work demonstrates the efficacy of amorphous polyhydroxyalkanoate (a-PHA) copolymers in enhancing the impact strength of PLA without compromising the compostability and bio-based carbon content of the final product. The influence of PHA polymer composition on the performance of PLA will be highlighted for applications including thermoforming, film and injection molding. Finally, the morphology of the blend will be used to explain the impact modification mechanism. Blends of 100% bio-based and fully biodegradable a-PHA and PLA exhibit good toughness and clarity in injection molding, extruded sheet and blown film. It will be shown that the level of toughness increase and modulus reduction can be tuned by blend composition.

About the Speaker

Raj Krishnaswamy is currently the Vice-President of Polymers R&D and New Business Development at CJ Bio (Industrial Biotechnology Division), where he is part of a team that is developing applications to commercialize a new family of biodegradable and biobased PHAs. He has 20+ years of polymers R&D experience at Chevron Phillips Chemical, Metabolix and Braskem prior to his current stint at CJ Bio. Raj is a co-inventor on 40+ patents and a co-author on 40+ publications. He is a Fellow of the Society of Plastics Engineering (SPE), has also been recognized with the Research/Technology lifetime achievement award by the SPE and is an alumnus of the NAE Frontiers of Engineering. Raj also serves on the advisory boards of the Macromolecules Innovation Institute at Virginia Tech and the Chemical Engineering Department at the University of Kentucky.

Shape-Memory Polymers Based on Castor Oil and Lignin Sulphonate Synthesized from Waterborne Dispersion

Summary

Aqueous polyurethane dispersions based on castor oil and lignin sulphonate (LS) were successfully synthesized in homogenous solution with no organic volatile compounds and excellent dispersion stability. Transparent thin films of PU-LS with different LS contents were obtained via solution (dispersion) cast technique. The glass transition temperatures (Tgs) of the PU-LS films were evaluated from the dynamic mechanical analysis (DMA) at 1 Hz and 2 oC/min heating rate. The Tg was found to be strongly influenced by the incorporation of the small LS content. The Tg (temperature of tan peak maximum) for PU-LS film with LS content lower than or equal 3 wt.% increases considerable with increasing the concentration of LS. For higher concentrations, no significant additional increase in the Tg was observed. The crosslink density was also calculated from the elastic modulus at a temperature of 40 oC higher than the Tg based on the rubber elasticity theory. The crosslink density increases with increasing the LS content of the thin films. The thermal-induced shape-memory effect was investigated using DMA according to cyclic thermomechanical tensile tests. The PU-LS thin film was found to have an excellent shape-memory effect and the recovery was strongly dependent on the LS content. Fast recovery (17 sec) to the permeant shape was observed once the temporary shape sample was immersed in water bath at the programming temperature.

About the Speaker

Dr. Madbouly received his Ph.D. from the Department of Organic and Polymeric Materials, Tokyo Institute of Technology, Japan. He has been awarded the Alexander von Humboldt postdoctoral Fellowship (Mainz University, Germany) and the Japan Society for Promotion of Science Postdoctoral Fellowship (Tokyo Institute of Technology). He served as a senior research scientist at the School of Polymers and High Performance Materials, University of Southern Mississippi and at the Center for Biomaterial Development, Institute of Polymer Research, GKSS, Germany. He also worked as Research Assistant Professor in the Department of Materials Science and Engineering at Iowa State University and Senor Polymer Engineer at Schlumberger. He published over 85 peer-reviewed journal papers with approximately 2600 citations. He also published 8 patents, one book, 9 book chapters, and presented more than 60 talks at national and international meetings, and serves as a frequent reviewer and referee.

Curing Behavior Simulator for Robotic 3D Printing of UV-Curable Thermoset Polymers

Summary

Robotic 3D printing systems utilizing photopolymers can enable free-standing structures, large-scale printing, extensive mobility, and increased part complexity. However, to better estimate robotic printing parameters and eliminate expensive trial-and-error approaches, a simulation framework for curing behavior is needed. In this work, an autocatalytic curing model, considering printing speed, UV light intensity, spotlight diameter, and filament thickness, was used to create a MATLAB simulation to study the effect of different printing parameters. The printed filament was discretized into a set number of elements over its length and thickness. UV light exposure time above each element was derived based on spot diameter and printing speed. This simulation framework, combined with experimental data (real-time ATR-FTIR), can better inform decisions regarding printing parameters selection. Overall, it was estimated that a speed 3 mm/s with a filament thickness 2 mm would produce acceptable ranges of degrees of cure at different UV light intensities and spot diameters. Finally, control of printing parameters (robotic arm movement and UV light intensity) to obtain a specific degree of cure (DoC) ensuring structural rigidity is demonstrated for a two degree-of-freedom manipulator, showing both the desired end-effector position and the desired DoC (60%) are achieved in four seconds.

About the Speaker

Genevieve Palardy is an Assistant Professor in the Department of Mechanical & Industrial Engineering at Louisiana State University. She previously obtained her PhD degree in Mechanical Engineering at McGill University, and was a postdoctoral researcher in Aerospace Engineering at TU Delft in the Netherlands. Since joining LSU in 2017, she has developed externally funded, multi-disciplinary projects on ultrasonic welding of thermoplastic composites and additive manufacturing using robotic systems. She is a 2021 NSF CAREER award recipient in the Advanced Manufacturing program.

Scale Up Optimization of Optical Nanolayer Films: Improved Thickness & Compositional Control

Summary

A nanolayer coextruded optical film process was scaled up and optimized to show improvements in the thickness and compositional control at production level throughput rates. Adjustment of processing temperatures, implementation of online continuous gauging and automatic die lip adjusting equipment, and upgrades to the cast film pinning system led to improvements of film thickness control. A unique profile control scheme utilizing only the middle layer's thickness instead of the total film thickness has been successfully utilized to control the critical layer's thickness. Automation and optimization of the extruder's feeding system provided compositional control capable of meeting tight quality specifications. With these improvements, production scale throughput rates of high-quality optical cast film capable for unique gradient refractive index (GRIN) optical applications were demonstrated.

About the Speaker

Michael Cantwell is a young professional, looking to learn from and add as much value to the people he is surrounded by. He has been blessed with many great opportunities and wishes to always take full advantage of each one.

He graduated from the University of Tennessee with a bachelor's degree in chemical engineering while also playing football for the university. The skills and experiences developed during his time at the university were used to become a successful process engineer for a plastics masterbatch manufacture, Techmer PM. While at Techmer, he quickly grew into more responsibility at the plant from implementing process improvement projects to leading groups developing training programs. One specific training program standardized report formatting throughout the company nationwide and gave effective training tools to new operators for reporting machine time.

Not only did Mr. Cantwell grow into more responsible roles at Techmer, but took on his own investment projects. He successfully managed a house renovation yielding just over 30% return on investment in just under 6 months. A process improvement product was also developed for an automotive supplier. This simple but effective product was made possible by noticing an opportunity in his personal network. The interpersonal skills and networking were key to making these projects successful.

Now Mr. Cantwell is continuing his education at Cleveland State University in a chemical engineering master's program. His research is helping to lay the foundation for novel bio-nano hybrid materials and to further the research of boron nitride nanotubes. He also has been advancing his entrepreunerial skills through the iCorps@Ohio program using the lean-startup methods.

Diffusion-Softening of Cellulose Nanocrystal and Thermoplastic Polyurethane Composites

Summary

Smart materials that can adapt their mechanical response in the presence of an external stimuli are popular for their applications in 4D printing. Such printing methods exploit a smart material's capability to interact with these stimuli to impart controlled material deformation tailored to specific applications. A modified percolation model was formulated to predict the dynamic transition exhibited in polymer composites containing cellulose nanocrystals (CNCs) which undergo mechanical softening in the presence of water. Coupling the effects water diffusion to the degree of CNC connectivity provided a method to capture the dynamic softening of CNC-based, water responsive smart materials as a function of filler loading. This modeling approach can be implemented to develop humidity sensing actuators and water-sensitive shape memory devices.

About the Speaker

TBA

Chemorheological Analysis of Slow Reacting Polyurethanes

Summary

Tracking the cure progress of slow reacting, uncatalyzed polyurethane systems is a tedious, time consuming process that has been largely neglected due to the availability of catalysts. The use of catalysts has enabled quick, non-isothermal studies to dominate the field of research, but when catalysis is not an option, these methods become impractical. In this context, we can use chemorheology to correlate viscoelastic data to several previously developed cure models. The models presented here examine viscosity buildup, reaction rate progress, and thermodynamic behavior, while emphasizing the importance of interpretation during data analysis. These chemorheological techniques focus on the development of thermally curing networks during subjection to flow fields, and apply to a vast array of thermosetting polymeric materials.

About the Speaker

John Reynolds is a third-year Chemical Engineering PhD student in Dr. Michael Bortner's lab at Virginia Tech. John's specific area of research is the rheology of highly filled polymer systems for additive manufacturing, with a unique focus on the thermal/UV curing capabilities of reactive filled systems.

Novel Nanocellulose Based Supports for PHBV Composites—Synthesis and Properties

Summary

Novel nanocellulose based nanostructures modified with hyperbranched polymers were prepared by using isocyanate linking chemistry. The chemistry was investigated using FTIR spectroscopy. The composites were homogenized utilizing solvent casting followed by injection molding of the samples. The thermal properties of the prepared samples were investigated using DSC and TGA.

About the Speaker

Kavan is a graduate student at the Clemson Composites Center working on sustainability in the field of plastics. Kavan's current projects are centered around making lignin-based polyamides, making PHBV-CNC composites, and recycling of post-consumer waste plastic. Kavan is a part of Srikanth Pilla's research group as a Ph.D. student.

Turnkey Solution for 3D Metal Printed Conformally Cooled Injection Mold Inserts

Summary

In Spring of 2020, Instaversal was contracted to test our newly developed conformal cooling technology, CoolTool™, against existing production benchmarks for a plastic injection molded Pipe Bracket Adapter. The Product Innovator was going through a period of elevated demand where the current cycle time of the existing injection mold tool prohibited them from meeting their demand. When cooling cycles were sped up this led to higher scrap rates due to sink marks. This left the Product Innovator with two options: delay delivery of the product to their top customer with the risk of losing the sale and potentially losing the customer or to invest in additional injection mold tools to double production capacity. To meet the customer's demand, 100,000 parts needed to be produced in a 60-day time period. This request created conflict with the contract manufacturer. They were being asked to absorb the cost of additional molds to meet the timing or run full 24-hour (Monday-Friday) shifts over the 60-day period which would create losses in revenue by eliminating other clients' scheduled jobs.

About the Speaker

Gaurav is an Advanced Concepts Engineer at Instaversal. He did his Master’s in Industrial and Engineering Management. His goal is to gain as much knowledge as possible and to contribute to society in the field of Innovating Injection molding technologies. Various other research interests include six-sigma, electric vehicles, and powertrain applications, process engineering.

Melting Performance Analysis of A Single-Screw Extruder With a NSB Screw

Summary

A recent design of a new screw referred to as the No Solid Bed (NSB) screw was introduced and the initial operation was presented. This new screw has channels in the transition section that do not allow a compacted solid bed to form. The data presented here compliments the data that was previously published.

About the Speaker

Dr. Xiaofei Sun is a Research Scientist from Dow Chemical. Dr. Sun's dedication of research is extrusion and compounding process, in particular, single-screw extrusion screw design, process optimization and troubleshooting.

Melting Performance Analysis of A Single-Screw Extruder With a NSB Screw

Summary

There has been a common goal among various researchers across the globe to investigate sustainable and high-strength materials as a suitable replacement for metallic materials in many industrial sectors. Many products obtained through reinforcing steel can potentially be replaced with those synthetic fibers such as carbon and glass to overcome the critical issues pertaining to dimension stability along with the creep effect that could pose complications in applications such as belts driving heavy machinery. In the current study, Steel, Carbon, and glass fibers were reinforced in TPU matrix and manufactured by compression molding. The resulting composite materials were then tested for tensile analysis. After comparing the mechanical properties of the fibers, it was observed that the carbon/TPU showed the highest load-bearing capacity, followed by steel and glass-reinforced TPU composites. The results also opened up the possibilities for carbon fibers to be a suitable replacement candidate to the steel cords that are used in applications such as conveyor belts for providing the required tensile strength.

About the Speaker

Dr. Ghaus Rizvi is a professor in the Department of Mechanical and Manufacturing Engineering at the Ontario Tech University, Oshawa, Canada. His research interests include polymer and composite processing, ‘Green’ composites, nano materials, bio engineering and additive manufacturing.

Fitting of Tait Coefficients for Molding Simulation

Summary

For several decades, the Tait model has been used in simulation software to describe the volumetric mechanical behavior of thermoplastic polymers as they cool. It is used to compute the residual strains and stresses of the polymer as it solidifies, but there is a problem. Many data sets have coefficients where there exists a discontinuity at the transition between the molten and solid domains. This paper outlines some basic checks that can be done to detect this problem and a procedure to fit the coefficients to data so that this problem does not arise.

About the Speaker

Senior Applications Engineer on the Global Technical Support Team at Altair Engineering, Paul graduated from Culver Military Academy in 1987, Aquinas College in December 1992 with a BA in Philosophy, an AAS from Grand Rapids Community College in Plastics Engineering in May 1996, and a BS in Plastics Engineering Technology from Ferris State University. After graduation, and getting into simulation, he took Calculus 3, Differential Equations, and Dynamics & Vibrations to supplement his education and enable him to perform meaningfully with his peers in simulation analyses. He started in plastics as a machine operator, then mold setup, then moved into processing, and finally into manufacturing engineering at Lescoa Inc. before transitioning into simulation at Hoff & Associates in 1999. In late 2001, he moved to Cascade Engineering, doing molding and structural analyses. He excelled at problem solving and over the years have devised analyses techniques that extended beyond the assumed limitations of the software tools available. He has been at Altair since November of 2007. He has supported many of our applications over the years and taught classes in both our front end applications and many of our solvers for mechanical, crash, CFD, and Manufacturing solutions. He has written some internal applications and authored a few training classes related to injection molding for Altair, including one due to be launched next year, "Polymer Properties for Simulation," which covers properties for simulating with polymers in the context of structures as well as rheological simulation.

Potential of Five-Axis Kinematic Systems for Additive Manufacturing Using Fused Deposition Modelling (FDM)

Summary

Fused Deposition Modelling (FDM) technology is a widely used additive manufacturing processes. In this process, a plastic filament is fed to a nozzle, melted there and deposited in the X, Y direction based on an imported geometry. Afterwards the print bed moves one layer in the Z direction and starts depositing the plastic again in the X, Y direction. These steps are repeated until the component is completely built up. In a recently developed system by one of the authors, the degrees of freedom in movement of the print head are extended to five axes: X-, Y-, Z-movement in translational direction plus an additional degree of rotation of the print bed and the possibility to tilt the print head with respect to the printed surface. Thereby, the surface quality and the geometric accuracy for rotationally symmetrical parts are intended to be improved. This paper investigates the potential of the additional motion axes with respect to part quality. To determine the accuracy, surface quality and the ability to print overhangs, tests have been carried out and compared to conventional manufactured FDM parts (X, Y, Z-kinematics). In a further step, the printing of the components after model preparation in polar coordinates is compared to printing in Cartesian coordinates. To investigate the influence of the print head adjustment on part quality, namely surface roughness, test runs were performed with print head adjusted at different angles to the surface. Suitable demonstrators were developed for this purpose and evaluated in comparison with manufactured FDM parts using commercially available printers limited to X, Y, Z-movement only. The tests show that the recently developed 5-axis printer has a lot of potential. It's comparable in performance to a commercially available FDM printer from the mid-price segment. The possibility of tilting the print head is the biggest advantage of the system. This has significantly improved part quality when printing overhangs and angled surfaces. The comparison between polar and cartesian coordinates showed an improvement in surface quality for cylindrical parts printed by polar coordinates.

About the Speaker

Education

Practical Experience

Other Knowledge

Good dominion of the English language. Very good knowledge of Microsoft Office and Creo2.0. Basic Knowledge of Solid Works. Also have knowledge of C++ and C# along with being a CNC specialist in Carpentry

Insterests & Commitment

Voll has been tutoring in Mathematics and Physics since June 2010.

Hobbys are sports, cooking, foreign cultures and technology.

Potential of Five-Axis Kinematic Systems for Additive Manufacturing Using Fused Deposition Modelling (FDM)

Summary

Functionally gradient 3d printing is of great importance for polymer composites to be applied in soft robotics or smart electronic devices. Imparting mechanical gradients within the design of new materials would help to prevent premature failure of devices and could reduce strain mismatches. In this work, we first focus on investigating the mechanical gradients and water responsive behavior of cellulose nanocrystal (CNC) / thermoplastic polyurethane (TPU) films by changing the concentration of CNCs. After generating masterbatched feedstocks, CNC/TPU films were extruded with a single screw extruder to obtain 3D printable filaments. The thermal and rheological behavior of the nanocomposite system is characterized to evaluate the mechanical property gradient of CNC/TPU filaments as a function of CNC concentration within a 3D printed geometry.

About the Speaker

Yimin Yao is a second-year PHD student in Chemical Engineering department at Virginia Tech. Yimin is working in Prof. Michael J. Bortner's Polymer Composite and Materials Lab.

Potential of Five-Axis Kinematic Systems for Additive Manufacturing Using Fused Deposition Modelling (FDM)

Summary

Presently, polymers such as high density polyethylene (HDPE) are utilized for an extensive array of applications because of their low weight, economical production, and exceptional physical and chemical properties. Thermal analysis and rheological measurements are the ideal techniques for characterizing the material properties of polymers. This paper employs thermo-gravimetric analysis (TGA), differential scanning calorimetry (DSC), and capillary rheometry to collate the contrasting nature of two HDPE resins. These resins will be referred to as HDPE A and HDPE C and are similar to two resins (Sample A and Sample C) included in a previous publication that focused on blow molding parison sag and swell. TGA was used to investigate the thermal stability of these polymeric materials, as they were ultimately decomposed inside a furnace. DSC was conducted to examine the thermal transition behaviors of the polymers. Capillary rheometry was run to construct shear viscosity and extrudate swell versus shear rate data through single and twin bore configurations under varying temperatures. These measurements were conducted under testing conditions that are representative of industrial processes, such as extrusion blow molding. HDPE C was found to exhibit greater extrudate swell than HDPE A, as measured by capillary rheology measurements, and these data correspond to the earlier published results that Sample C exhibited greater parison diameter, thickness, and weight swell than Sample A as measured with a lab scale extruder.

About the Speaker

Dr. Azizeh-Mitra (Amy) Yousefi's current and past research has been on polymer processing (blow molding and thermoforming) and on 3D-printed biomaterials for tissue-engineering applications. Dr. Yousefi received her Ph.D. in Chemical Engineering from Ecole Polytechnique in Montreal in 1996. After a postdoctoral fellowship in Applied Mathematics, she joined the National Research Council of Canada (NRC) in Quebec in 1999, where she was the recipient of "l'Ordre du M´rite" in 2002 (individual) and in 2006 (team). Dr. Yousefi joined Miami University in 2009 as the endowed Maryloo Spooner Schallek associate professor and was promoted to full professor in 2016. Her lab uses thermal and rheological characterizations, finite element modeling, design of experiments, additive manufacturing, and polymer processing for industrial and biomedical applications. The recent study in her lab on hierarchical 3D scaffolds was funded by the National Institute of Health (NIH). She has contributed to developing the curriculum for the new biomedical engineering program at Miami University, and was nominated for the Arthur Olson Generational Teaching Excellence Award in 2014 and 2015.

Effects of Processing Parameters on Microcellular Injection Molded Polyether-Ether-Ketone

Summary

In this study, the effects of key process parameters of MIM on microcellular PEEK tensile splines were studied for the first time. By changing process parameters, the effects of melt temperature, injection speed, injection volume, and gas concentration on microcellular PEEK's weight-reduction ratio, cell structure and tensile properties were studied. The results show that injection volume and melt temperature have relatively significant influence on weight-reduction ratio and tensile strength, and the change of melt temperature, injection speed, and injection volume can significantly alter the cell structure. Furthermore, owing to PEEK's reasonable foamability due to its strong melt strength, microcellular PEEK's cell density is higher than 108 cell/cm3 and cell size is around 10 μm. Under suitable conditions, samples with the weight-reduction ratio of 15.94%, tensile strength of 70.45 MPa, and tensile modulus of 3142 MPa can be obtained, respectively, which are superior to most of the existing unreinforced microcellular materials. This work laid the foundation for the further fabrication of high-strength and lightweight microcellular PEEK materials.

About the Speaker

Professor Lih-Sheng (Tom) Turng received his B.S. degree in Mechanical Engineering from the National Taiwan University, and his M.S. and Ph.D. degrees from Cornell University. He worked at C-MOLD developing advanced injection molding simulation software for 10 years before joining UW–Madison in 2000. His research encompasses injection molding, nanocomposites, multi-functional materials, bio-based polymers, and tissue engineering. Professor Turng is currently the Consolidated Papers Professor and the Co-Director of the Polymer Engineering Center and Group Leader at the Wisconsin Institute for Discovery (WID), a Fellow member of the American Society of Mechanical Engineers (ASME), the Society of Plastics Engineers (SPE), and the Society of Manufacturing Engineers (SME), the recipient of the 2018 Wisconsin Alumni Research Foundation (WARF) Innovation Award, and an Honored Service Member of the SPE. Professor Turng has published 300 refereed journal papers and over 250 conference papers/presentations and has 12 Best Papers awards and 20 patents and patent applications.