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
Characterizing Scrap Vinyl Flooring to Determine Feasible Reuse Options
Andrew Lawrence, May 2000
The manufacturing waste generated during the production of vinyl floor tiles is typically sent to landfills, rather than recycled, because of a lack of reuse options for this material. This waste is typically PVC loaded with approximately 80% limestone. The goals of this research are to characterize this material to determine the feasibility of reprocessing it and to measure the mechanical properties of the processed material. This study will also attempt to suggest an injection molding or extrusion application for the mixture.
A Method to Characterize the Impact Properties of Hand Tools
John Stanko, John Kennerknecht, May 2000
There does not currently exist a method for the characterization of the impact properties of hand tools, specifically screwdrivers. Without a scientific method of collecting data for various designs, it is difficult for manufacturers to determine the effect of material or design changes on the impact properties of the product. The most demanding application for these hand tools can often be a hammer blow to the handle of the product, and therefore this abuse must be strongly considered in the design criteria.
Applications of Thermal Analysis in the Design of a Bulk Continuous Acrylic Copolymerization Process
M-W. Young, M. Xanthos, May 2000
DSC analysis is conducted to obtain kinetic information of the chain addition copolymerization in bulk of a quad-monomer acrylic system. The experimental variables include reaction temperature, type of peroxide and peroxide concentration. By assuming that the copolymerization is a simple reaction, the approximate apparent order of the reaction can be identified; and along with the heat of reaction information, it is demonstrated that the DSC analysis is very useful in facilitating the parametric design process of a continuous stirred tank reactor (CSTR) operation. Selected results of conversion and cumulative copolymer composition of the CSTR samples are included. A more rigorous approach of analyzing the reaction kinetics of the copolymerization is also briefly addressed.
Non-Isothermal Modeling of Co-Rotating and Contra-Rotating Twin Screw Extruders
Th. Avalosse, Y. Rubin, L. Fondin, May 2000
The quality of the mixing of different raw materials, i.e. the uniformity of the mixture, is a key issue that will determine the morphology and the specific product properties of the resulting compound [1, 2]. Numerical simulation of flow in extruder components provides a new insight, both qualitative and quantitative, into those features. 3-D transient numerical simulations of twin screw extruder (TSE) configurations are presented. A special method, the mesh superposition technique (MST), has been introduced to provide a convenient way to model intermeshing TSEs without involving any remeshing complexity [3]. It has been validated in previous work for isothermal cases [4]. To account for the important non-isothermal effects, the method is compared against numerical and experimental results for additional, non-isothermal validation [5]. We present an analysis of different non-isothermal features that characterize the flow induced by a co-rotating as well as a contra-rotating configuration. Both cases are compared in terms of pressure profiles, temperature fields, resulting torque imposed on the screws and from a mixing point of view to illustrate a typical analysis of different TSEs and provide objective information to select the most appropriate configuration for specific process requirements.
Branching of Polypropylene with a Polyfunctional Monomer for Extrusion Foaming and Thermoforming Applications
D.W. Yu, S.K. Dey, F. Pringgosusanto, M. Xanthos, May 2000
Melt strength of polymers is one of the primary criteria for the success of low-density extrusion foaming and thermoforming processes. In this paper, branching of PP using polyfunctional monomer was studied in a batch mixer and a small scale co-rotating twin screw extruder as a function of modifier concentration and process conditions. Melt viscoelastic properties of the products, related to melt strength/elasticity, including die swell and recoil, were investigated to examine the degree of long chain branching, which could lead to improve foaming and thermoforming processability. The melt strength of those materials was compared with that of a commercial high melt strength PP and an unmodified general purpose PP.
Small Angle X-Ray Scattering Study of EACE Processed Semicrystalline PET
Zhiyong Xia, Hung-Jue Sue, Thomas Rieker, May 2000
Semi-crystalline poly(ethylene terephthalate) (PET) was shear orientated by the novel Equal Channel Angular Extrusion (ECAE) process. Small angle X-ray scattering indicates that extrusion induces preferred orientation of the lamellar structure. Before passing the shear plane, the material has a weak orientation. But after passing the shear plane two preferred orientations are formed in the extruded region; one perpendicular to the shear plane; the other 45° from the shear plane. The physical and mechanical properties of the extruded PET were also investigated and found to correlate well with the ECAE-induced shear orientation.
Experimental Determination and Numerical Modeling of Morphological Development during Injection Molding of Self-Reinforcing Composites
Zhigang Li, Kwabena A. Narh, May 2000
The correlation between structure development during injection molding, and the tensile modulus of injection molded PET/LCP blends were studied, through experimentation and numerical simulation. Process parameters were varied to determine their effects on the tensile modulus and structure development of the blends. A combined numerical simulation and analytical calculations, has been used to model the experimental results. A model that establishes the relationship between the aspect ratio of LCP fiber, the elongational strain, and the tensile modulus, enables us to predict the processing dependent morphology and tensile modulus of injection molded blends.
Predicting Creep in Bottle Design
Ivan McCracken, May 2000
Experimental creep is data collected to drive an FEA program, ultimately used to predict bottle deformation caused by an internal pressure. The results indicate that it is possible to predict bottle deformation using existing creep data, but it is a highly manual process. The FEA program is beneficial in determining stresses caused by internal pressures, which can then be used to calculate deformations. True deformations can be calculated for segments of a bottle using FEA, but a new approach has been suggested, which will allow the FEA program to calculate the deformations along the entire sidewall of the bottle.
A Study of the Tensile Creep Behavior of Wood Flour Filled HDPE in Aqueous Mediums
John Raybuck, Daniel Heuer, May 2000
Wood flour filled polyethylene can be used as a replacement for conventional lumber in the waterfront structure industry. The effect of large amounts of moisture and submersion in fresh and salt water on the long term mechanical properties of these materials is important to understand. This study will examine the tensile creep behavior of wood flour filled high density polyethylene in air, fresh lake water, and salt water. An apparatus for aqueous tensile creep testing has been designed and built, and will be used to gather data for this study.
Modeling Gate Freeze in Hot Runners Using CAE
James J. Chiamardas, May 2000
When using computer flow simulation software to predict gate freeze time in hot runners it is hard to know how to correctly model the hot drop tip to accurately correlate the gate freeze time. This study will attempt to use computer flow simulation to correlate the gate freeze time of hot runners predicted by the simulation to actual gate freeze times. This will be done by changing a model to make the gate freeze prediction match an actual molded part, and observing how these changes affect the rest of the model.
A Biodegradation Study of Co-Extruded Nanocomposites Consisting of Polycaprolactone and Organically Modified Clay
Rich Farrell, Steve Goodwin, Carl Wirsen, Jeanne Lucciarini, Mathew Martinez, Jo Ann Ratto, May 2000
Nanocomposites containing biodegradable polymers and clays were investigated to improve biodegradable properties. Polycaprolactone (PCL) (83,000 and 43,000 g/mol molecular weight) was mixed with additions of either 2 or 5% of synthetically modified montmorillonite clay. A twin screw extruder was used to produce the pellets. The pellets were then co-extruded with multilayering technology to produce 15-inch wide films from a 256 and 1024 layer die multiplier configuration. This study focuses on the biodegradation studies in compost, soil, and marine environment with results showing improved biodegradation rates in selective nanocomposites and environments.
Flow-Induced Migration Phenomena in Polyethylene/Polyethylene-co-maleic Anhydride Blends
Hojun Lee, Lynden A. Archer, May 2000
Flow-induced migration of polyethylene-co-maleic anhydride (PE-co-MA) additives in a polyethylene (PE) melt is investigated using long-chain branched polyethylene covering a range of melt index. Attenuated total reflection infrared (ATR FTIR) spectroscopy and interfacial tension measurements were used to characterize surface composition of copolymer additives processed by a melt extrusion. Experiments covering a range of shear rates, die length/diameter and extrusion temperatures are described. The surface concentration of copolymer additives were changed from the bulk to the surface of extrude depending on the shear rate and temperature due to the shear-induced diffusion of macromolecules. A mechanism based on stress-induced diffusion is proposed to explain the observed surface migration phenomena.
Blends of CO2 and 2-Ethyl Hexanol as Replacement Foaming Agents for Extruded Polystyrene
Louis E. Daigneault, Richard Gendron, May 2000
By the year 2010, HCFC 142b will be banned for use as a foaming agent for extruded polystyrene (PS) foam in North America. Many blends of foaming agents have been patented as replacements to expand PS. In this study the optimal concentration of a previously unexplored blend of CO2 and 2-ethyl hexanol (2-EH) is shown to allow the production of PS foam of 30 kg/m3 density. The glass transition temperature reduction of the PS, due to the incorporation of 2-EH, is believed to be an important contributor to the success of this foaming agent blend. In long-term use of the foams, the 2-EH does not measurably diffuse out of the PS whereas the half-life of CO2 diffusion out of the foam is measured in weeks.
PS Foam Moldings Expanded with HCFC 141b
Louis E. Daigneault, Fadéla Ouraghi, Nicole Côté, May 2000
Medium and high density polystyrene foam moldings were produced by compression and injection molding. Polystyrene (PS) was first impregnated with HCFC 141b and pelletized. These impregnated pellets became the feedstock in injection and compression molding, with cycles typically lasting between 1 and 30 minutes in duration. The compression molding cycles were studied to optimize the mold release method and the cycle times ascribed to heating, pressure release and sample cooling. The lowest foam density reached was 196 kg/m3. While residual foaming agent in the matrix negatively impacts on the mechanical properties of the foam, the results of this work demonstrate that a physical foaming agent is feasible for compression molding and short-shot injection molding of PS. It should however be pointed out that HCFC 141b will be banned for use in the U.S. by the year 2003 and in Canada by 2010.
Fracture Toughness Variations of Injection Molded Long Fiber Reinforced Thermoplastics
Fernando Gonzalez, Constantin Chassapis, May 2000
The fracture toughness, defined as Kc, of injection molded long fiber reinforced polypropylene with 50% E-glass and its variations is investigated. Rectangular plaques of different thicknesses at various sets of processing conditions have been fabricated. In order to assess the spatial variation of the fracture toughness, specimens aligned in the direction of the injection molding flow and perpendicular to it, have been obtained and tested at pre-selected locations. The morphology of the samples consisting of flow induced through-thickness layers was also evaluated experimentally and related to the fracture toughness, thus showing the effect of the part morphology on such mechanical property.
Method for Injection Molding a Crosslinkable Extrusion Grade of PEX
James Kopchick, Eric Moore, May 2000
Crosslinkable Polyethylene (PEX) has been used in pipe extrusion for the unique properties obtained by crosslinking. The most important property being its elevated HDT (heat deflection test), which allows the material to be used in higher temperature applications. This paper is the development of a method for using PEX in an injection molding application. The factors of concern are property loss, cure time, temperatures, screw rpm, and residence time. This study will show that it is feasible to use PEX in injection molding. The cure time as well as processing conditions will be recommended.
New Routes to Market in the 21st Century
Roger F. Jones, May 2000
The plastics industry is hurtling toward the 21st century while undergoing remarkable changes that are completely reshaping the way business has been done previously. Restructuring, consolidations, portfolio swapping and joint ventures are taking place on an unprecedented scale and pace. E-commerce has added to globalized competition and new routes to market are emerging as old business models fade away. How will polymer manufacturers sell their goods in the future? Has the use of distributors peaked? Is the Internet the future? These changes will be analyzed and their impact on people and companies in the industry projected.
Color Effects of Modified Rubber on Black Colorant in Polypropylene
Eric B. Hunt, May 2000
The primary use of modified rubber is to improve flexural modulus and impact strength. The disadvantage of using modified rubber is the distortion of color when used as an additive to a polymer. This study compared the color shifts of a black colorant with differing loadings of modified rubber.
New Fast Peroxides for PVC
Kenneth W. Dixon, May 2000
Recent economic trends in the PVC market have pushed producers to reduce costs and improve productivity. Areas were sought where peroxide expertise can be utilized to develop new initiators that can help. Consequently a new developmental, fast peroxide for PVC, D-174, is being introduced which is reactive at lower polymerization temperatures, gives a more square heat profile and produces shorter polymerization cycle times for the PVC manufacturer.
Thin Wall Injection Molding of Thermoplastic Microstructures
Liyong Yu, Yi-JeJuang, Kurt W. Koelling, L. James Lee, May 2000
Thin-wall injection molding is a key technology allowing the low-cost mass production of microstuctures, such as devices with surface-relief microcomponents widely applied in micro-optics, micro-fluidics, medical and biotechnology. Research was performed in order to gain better understanding of important parameters in injection molding of thin-wall microstructures. A series of injection molding experiments were conducted with PC and PMMA, which are common materials in bio-MEMS (Micro Electro Mechanical System) applications. The rheological properties were characterized through dynamic, and transient shear viscosity measurement using a Rheometrics Mechanical Spectrometer. Micro-channels of different lateral and depth dimensions were obtained on thin wall substrates. The Scanning Electronic Microscope (SEM) photos were used to measure the fidelity and roughness of the replicated plastics. Birefringence was used to qualitatively examine the amount of residual stresses in the molded parts.


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"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
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