SPE Library
The SPE Library contains thousands of papers, presentations, journal briefs and recorded webinars from the best minds in the Plastics Industry. Spanning almost two decades, this collection of published research and development work in polymer science and plastics technology is a wealth of knowledge and information for anyone involved in plastics.
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Conference Proceedings
Performance of Susceptor Materials in High Frequency Magnetic Fields
Russell J. Nichols, Drew P. LaMarca, Bryan Agosto, May 2006
Joining of thermoplastics by electromagnetic implant welding is a mature process, yet little information is found in the literature to describe the relationship between the properties of magnetic susceptor particles, the plastic matrix materials in which they are dispersed, and their interaction with high frequency electromagnetic fields.Magnetic implant welding uses susceptors that couple, due to ferromagnetic hysteresis, with high frequency electromagnetic radiation to generate controllable heat in the plastic. The relationship of coupling distance, power level, and frequency to the heating response of susceptors is studied.Conclusions are presented, based on the results of statistically designed experiments, that suggest optimal conditions for effective welding processes.
Preparation and Characterization of Polymeric Capsules Containing Functional Additives
K. Park, W. Feng, K. Kim, M. Xanthos, May 2006
In attempts to develop novel functional additives for thermoplastic and thermoset polymer coatings, various sizes of microcapsules containing a silicone fluid which could facilitate the release of the coating from a metallic substrate were prepared by in-situ polymerization. Fill content, size of capsules, wall-thickness, and surface morphology were observed by TGA, TEM, SEM, EDX, optical and NMR microscopy. The capsules were dispersed in polymeric coatings and the release of their content through mechanical means was followed microscopically.
Optimization of Process Parameters of an Injection Moulded Gear Using Taguchi Methodology
K. Jayanarayanan, H.S. Karthick, V. Suganya, A.L. Shivashankari, S.S. Bhagawan, May 2006
This paper suggests a systematic approach to reduce defects in injection moulded components. The component taken for analysis was an injection molded gear made of Stanyl (Nylon 4, 6)-15% Carbon Filled, used in an automobile. The analysis applies Taguchi Methodology to investigate the effects of process conditions on the shrinkage and warpage characteristics of the product made from a two cavity injection mould. The effect of seven process parameters on the Shrinkage and Warpage of the component were analyzed. An L18 standard orthogonal array (seven parameters with three levels) was chosen. The samples selected at random from each experiment were measured for warpage and shrinkage. The data thus obtained were analyzed with quality control tools like ANOVA (Analysis of Variance) and Factor Plots. Based on the results from ANOVA, the parameters which have significant effect on the quality of the product were identified. The factor plots gave information regarding the optimum levels of parameters to be maintained . The optimum levels of the parameters were used for conducting confirmatory experiments, which gave products with shrinkage and warpage within acceptable limits.
Enhanced Anhydride Coupling Agents for Wood Polymer Composites
David M. Dean, Anthony M. Angelo, Andrew Smillie, Karlheinz Hausmann, May 2006
In this study, we report on next generation coupling agents based on high molecular weight, random copolymers of ethylene and anhydride functional monomers that have been specifically designed for wood-polymer applications. A standard high-pressure free radical synthesis technique was used to create a high molecular weight ethylene copolymer with a very high level of reactive functionality (greater than 3 weight percent anhydride). This anhydride-functional- ethylene copolymer has been shown to improve the flexural strength and decrease the water absorption of wood-polymer composites when incorporated at loadings as low as 0.5 weight percent in the final part.
Mechanical Properties of Soy Protein Isolate/Soy Hydrolysate Plastics
Maria Vlad, Jay-lin Jane, Perminus Mungara, David Grewell, May 2006
Biodegradable plastics based on soy protein isolate were prepared with soy hydrolysate as a plasticizer via different methods, and the mechanical properties of the samples from the different processing methods were tested and compared. The results indicated that the tensile strength and the elongation at break of the samples with soy hydrolysate were enhanced when the preparation process consisted of extrusion followed by injection molding or compression molding, but no improvement was noticed in the case of the compression molding without prior extrusion.
Laser Transmission Welding of Colored Thermoplastic Elastomers and Hard Plastics
Akihide Isoda, Yoshiteru Hatase, Osamu Nakagawa, Heihachi Yushina, May 2006
Automobile and other part manufacturers have looked for ways to join dissimilar materials. Welding different kinds of resin together has been looked at for this purpose.Olefin thermoplastic elastomers colored with a transparent black colorant can be welded with polypropylene while keeping higher welding strength compared to the case of non-colored elastomers. Laser welding using black-colored thermoplastic elastomers has a variety of potential applications in the manufacture of automotive parts and electronic components.
A New TPU Featuring Low Tackiness
Limei Lu, Toprak Serhatkulu, Mahmound Ghanem, Armando Sardanopoli, May 2006
Thermoplastic polyurethanes are relatively tacky compared to other thermoplastic elastomers. The general practice in the plastic industry is to add waxes, lubricants or inorganic fillers to reduce the tackiness. Unfortunately, these additives have negative impact on final product performance and aesthetic property.A series of new TPU products featuring low tackiness, contact transparency and process efficiency that can be used in applications requiring low coefficient of friction in film, sheet, tubing etc. This paper will illustrate the features of the new products and their mechanical properties.
Ultrasound Aided Extrusion Process for Preparation of Polypropylene-Clay Nanocomposites
Sergey Lapshin, A.I. Isayev, May 2006
Two methods for the fabrication of PP/clay nanocomposites using a continuous ultrasound assisted process are compared. In the first approach a two stage process was implemented. The nanocomposites were prepared using a co-rotating twin screw extruder followed by a single screw extruder equipped with an ultrasonic die attachment. In the second method a single stage process was used. The nanocomposites were compounded using a single screw extruder with mixing elements and an ultrasonic die attachment. Two regimes of feeding were realized, namely, starved and flood feeding. The gap size in the ultrasonic treatment zone was varied. Die pressure and power consumption were measured. Similarities and differences of nanocomposites obtained by these two methods are discussed based on their rheological, mechanical properties, and structural characteristics.
Shape Memory Polymer Orthodontics
Changdeng Liu, Patrick T. Mather, Charles Burstone, May 2006
Shape memory polymers (SMPs) have been intensively investigated for multiple medical applications in recent years. In our lab, we have developed several SMPs with tailored transition temperatures, excellent shape fixing and shape recovery, and variable stiffness, with values ranging from > 1 GPa (hard) to < 1 MPa (soft). Recently, we have endeavored to apply two particular SMPs, a castable shape memory polymer (CSMP) and a shape memory rubber, to orthodontic appliances. We have measured the mechanical properties, water absorption, stain resistance, and stress stability and compared the results with currently used orthodontic polymers, revealing significant advantages. Prototype appliances are presently under evaluation. In this presentation, we will introduce the progress we have achieved and propose how SMPs can offer unique functionality to orthodontic appliances.
Development of a High-Pressure Slit Rheometer
Fritz Klaiber, Ivan Dario Lopez Gomez, Tim A. Osswald, Lih-Sheng Turng, May 2006
In thin - wall injection molding processes, parts thinner than 1 mm are produced using high injection pressures and velocities. Modeling has not been successful in predicting process physics during molding. We have built a high pressure slit rheometer that enables us to measure the rheological properties of polymers at elevated pressures and temperatures. Measurements were done with polystyrene, and the results showed the effect of pressure and the effect of viscous heating on the viscosity. Results from such measurements will allow us to introduce viscosity pressure effects during mold filling of Thin-Wall Injection Molding.
Viscosity of Soy Protein Plastics as Determined by Screw Extrusion Through a Capillary Die
Brian E. Ralston, Tim A. Osswald, May 2006
Processing of soy protein plastics using conventional methods (injection molding, extrusion) has met with some success. At this point the lack of data on fundamental flow behavior of soy protein plastics limits future advances. Previous work by Japanese researchers showed the effects of moisture content, temperature, and strain history on the viscosity of soy protein isolate at elevated temperatures. However, no studies to date have explored the viscosity of processable formulations that contain soy protein along with the necessary additives (e.g., glycerol and corn starch). Viscosities of several soy protein formulations are evaluated using screw-extrusion through a capillary die. The viscosities are found to conform to the power-law model, but are substantially higher than those of commodity petroleum-based resins.
Using Multilayer Films to Fabricate Reactive, Submicron Patterned Surfaces
Chun Zhang, Scott M. Husson, Douglas E. Hirt, May 2006
Highly layered structures are important to microfabrication and nanofabrication technologies as tools for understanding and controlling surface structures through manipulation of chemical and physical interactions. A new approach is introduced to create submicron patterned surfaces with surface chemical functionality using multilayer polymer films. Alternating layer structures of two immiscible polymers, linear low density polyethylene (LLDPE) and ethylene-co-acrylic acid copolymer (EAA), were formed by co-extrusion with subsequent compression molding. Thin sections of the multilayer molded sheets were prepared by microtoming and the highly layered microstructure was verified by SEM, TEM, and polarized optical microscopy. Regionally confined chemical functionality was confirmed by grafting a fluorescent label selectively to the alternating layers of EAA.
Surface Modification of Ethylene-Acrylic Acid Copolymer (EAA) Films Using Various Linker Layers
Chun Zhang, Ning Luo, Douglas E. Hirt, May 2006
Two reaction systems were developed to covalently graft polyethylene glycol (PEG) chains on ethylene acrylic acid copolymer (EAA) surfaces without significant penetration of reactants. The scheme involved surface grafting of link molecular l-lysine or link layer poly(glycidyl methacrylate) (PGMA), followed by covalent bonding of PEG chains. For the PGMA method, AFM images showed that large, isolated surface domains on the micron scale existed on the EAA surface because of phase separation during dip coating and drying of the PGMA. For the l-lysine method, NHS and EDC were used to activate the carboxylic acid groups of the EAA. After activation, l-lysine was grafted onto the EAA surface, followed by PEG grafting. Each step of the surface modification was followed by ATR-FTIR spectroscopy, XPS, and AFM.
Birefringence Distribution in Gas Assisted Tubular Injection Moldings
A.J. Carrillo, A.I. Isayev, J.W. Shin, May 2006
Average birefringence
Barrier Properties of Linear Polyethylene Films
Arild Follestad, Jorunn Nilsen, Irene Helland, May 2006
Barrier and permeability is important in several PE applications. This study gives a broad mapping of how permeability depends on the PE and on film thickness.PE’s were blown to films and permeability for water vapor measured. The results were expressed by:Permeability coefficient = (Amorphous fraction)* (Amorphous fraction dependent factor) * (Correction factor) / Thickness.The amorphous fraction dependent factor has two different regimes depending on amorphous fraction.The correction factor, which is basically 1, increases with decreasing amorphous fraction, MFR and film thickness.
Flame Retardancy and Rheological Behaviour of Acrylonitrile-Butadiene-Styrene Copolymer (ABS) Composites Filled with Magnesium Hydroxide Sulfate Hydrate(MHSH) Whiskers
Bo Liu, Yong Zhang, Chaoying Wan, Yinxi Zhang, May 2006
Flame-retardant ABS composites were prepared using MHSH whisker as a flame retardant. The morphology observation indicates that the addition of zinc stearate could lead to the uniform dispersion of the whisker and improvement of flame retardancy. With increasing whisker content, flame retardancy properties of the composites is improved, the viscosity and storage moduli of the composites increase at low frequency zone. The presence of zinc stearate leads to slight increases in the storage moduli.
Rapid Mold Temperature Control on Micro Injection Molded Parts with High Aspect Ratio Micro-Features
J.A. Chang, S.C. Chen, J.C. Cin, May 2006
Electromagnetic induction heating combined with water cooling are utilized to achieve a rapid mold surface temperature control for micro-feature injection molding process. Replication in molding micro features is greatly improved by rapid mold surface temperature rise within 60° to 140° using induction heating for about 2 to 3.5 seconds. Simulation shows that the E.M. wave can penetrate into micro channel bottom and cause about 2° difference temperature uniformity. For PMMA, complete replication of the 600µm depth and 30-50µm thick micro feature was achieved.
Effect of Epoxy Modifier on Flame Retardancy and Rheological Behavior of Acrylonitrile-Butadiene-Styrene(ABS)/Montmorillonite(MMT) Composites
Bo Liu, Yong Zhang, Chaoying Wan, Yinxi Zhang, May 2006
ABS/MMT composites were prepared via melt intercalation to MMT with or without pretreatment of liquid epoxy resin. For the direct addition of epoxy, the composite has intercalated structure; while for the pretreatment of MMT with epoxy, the composite has exfoliated structure. Cone analysis results reveals slight difference in flame retardancy between the two composites. At low frequency zone, the composite with intercalated structure has higher storage modulus than the composite with exfoliated structure.
Effects of Molding Conditions on the Conductivity Properties of Injection Molded Bipolar Plate Used for Fuel Cell
S.C. Chen, M.Y. Shih, P.H. Lee, J.S. Huang, May 2006
Fuel cell is an important energy source for the 21st century. Among fuel cell components, plastics have been chosen as a candidate material for bipolar plates which needs to fulfill the conductivity requirement. In this study, polymer polyphenylene sulfide (PPS) containing 50% carbon fiber was in injection molded and its conductivity was measured by the four point probe. The carbon fiber dispersion and orientation were examined by scanning electron microscopy (SEM). It was found that at high mold temperature, high melt temperature and lower injection rate, the carbon fiber distributed more uniformly leading to higher conductivity. High holding pressure closely tangled the carbon fiber, also increases conductivity. 3D-CAE simulations were also conducted to verify fiber dispersion and orientation under different molding parameters and show reasonable consistency.
Analysis and Experimantal Verification on the Optical Performance of Injection Molded Light Guide Plates with Micro-Feature Design
Shia-Chung Chen, Ching-Hsin Hu, Ming Chang, Li-Chi Su, May 2006
This study investigates the optical performance of light guide plates with micro-feature characteristics. The light guide plates are made of injection mold PMMA. Both one- and two-sided micro-feature designed patterns were conducted. The results reveal that the micro-feature with smaller interval of dot array would lead to better luminance. It is also found that the uniformity in luminance distribution can be greatly improved if proper geometry of micro-structure dot is arranged. In addition, the luminance can be improved as the elevation of the temperatures of melt and mold, filling speed and packing pressure. The luminance may achieve highest value under proper packing pressure.
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