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.

The SPE Library is just one of the great benefits of being an SPE member! Are you taking advantage of all of your SPE Benefits?

Not an SPE member? Join today!

Use % to separate multiple keywords.

Search SPE Library

Conference Proceedings

How TPV Out-Performs EPDM in Acoustic Properties for Automotive Sealing

James T. Browell, Shawn Jyawook, May 2007

A comparative analysis of TPV vs. EPDM with respect to noise reduction is examined for automotive weatherstrip body sealing applications. Specifically, EPDM sponge is compared with JyFlexTM, a TPV compound of equivalent stiffness. The study is performed using multiple acoustic tests (road and component), supported by FEA analysis as a diagnostic tool [1].

The Position of High Shear Material and its Effect on the Progressive Weld Line Strength of an Injection Molded Part

Kevin A. Welsh, Jason B. Willis, May 2007

This paper presents the results of a study on weld line strength as affected by materials, injection velocity, distance from the gate, and the strategic positioning of high sheared melt laminate prior to weld formation.

Strategies for Enhancing Cell Nucleation of Thermoplastic Polyolefin (TPO) Foam

S.G. Kim, J.W.S. Lee, C.B. Park, M. Sain, May 2007

There is a growing interest in developing foamed TPO since replacing solid TPO will reduce material cost and fuel usage. In this paper, various talc contents are added into a TPO matrix, consisting of PP blended with a metallocene-based polyolefin elastomer. The effect of talc on TPO foams blown with N2 is studied using the batch foaming simulation system. The influence of N2 content and processing conditions on cell nucleation behaviour is discussed.

Laser Transmission Welding of Polyamide Tubes to Plates

Bobbye Baylis, Paul Daly, Hans Herfurth, May 2007

A major technical hurdle to overcome in making an all-plastic heat exchanger is welding tubes to the base plates of tanks. A heat exchanger that must remove a large quantity of heat quickly requires a large number of tubes, usually closely packed. Various techniques to achieve this have been investigated. The materials for tubes and tank plates were all polyamides; various combinations of PA 66, PA 612 and PPA were studied. Data on successful laser welds are presented.

Fractionated Crystallization of ?-Nucleated Polypropylene Microdroplets Produced from Nanolayers

D.S. Langhe, Y. Jin, A. Hiltner, E. Baer, May 2007

Microdroplets of ?-phase polypropylene nucleated with the calcium salt of pimelic acid (Ca-Pim) and quinacridonequinone (QQ) were produced by layer breakup of Polypropylene (PP) / Polystyrene (PS) coextruded nanolayer films. These microdroplets were investigated using DSC and WAXD to study the effect of nucleating agent concentration and particle size distribution on fractionated crystallization. By using varying heating and cooling rates, the kinetics of crystallization of these microdroplets was studied.

Compressibilty of Resin, A New Look at Bulk Density

Adam J. Miloser, May 2007

The bulk density of a material greatly influences the total storage capacity in a silo. Although it has significant meaning, little research has been done in determining how compressive polymer materials are in their bulk states. The focus of this research is to investigate the changes in bulk density that occur with changes in pressure for several different polymer materials and determine the compressibility of these materials in the bulk state.

Analysis of the Stability of a Single-Screw Extrusion Process Using Graphical Analysis

John R. Wagner, Jr., Mark A. Spalding, Sam L. Crabtree, May 2007

This paper analyzes the barrel pressures and motor current data acquired using a high-speed data acquisition system. Graphical analysis shows the relationship between screw design and screw speed.

What Every Plastics Professional Should Know about Products Liability- Part 1: An Overview of Sources of Products Liability Claims

Amad Tayebi, May 2007

This article, particularly tailored to cover plastics materials products, provides an overview of the three major theories under which a products liability action may be initiated, namely; negligence, breach of warranty and strict products liability. Negligence liability claim elements of duty owed by the manufacturer, breach of duty, causation and damages are discussed. Also, discussed are claims brought under the theories of breach of warranty and strict products liability.

Polybutene-1: A Review of an Old Polymer Produced with a New Technology and its Application to Flexible Packaging

Omar M. Boutni, May 2007

Polybutene-1 is a polyolefin with unique characteristics which distinguish it from PE and PP. They include: low heat of fusion, shear thinning, creep resistance and an intriguing polymorphic structure. Compatibility of PB-1 with PP and immiscibility with PE are often exploited to create convenient packaging which is easily opened by the consumer. This paper will review examples of the use of PB-1 in such applications and in the modification of the sealing initiation temperature of films.

Modeling of a Thin-Walled Filament Wound Tubing

A.B. Coffey, C.M. Ó Brádaigh, A.G. Gately, May 2007

There is a need in biomedical engineering for thin-walled, high-performance structures, which could be used as catheters, or as replacement implants in the body. Reinforced thermoplastic materials are becoming exceptionally important due to their ease of fabrication and reduced costs of manufacture. This paper outlines the theoretical modeling of a filament wound catheter and the associated outputs from which a catheter with specific required properties may be designed.

Rheological and Degradation Properties of Renewable Resource Polymer Blends

Jason D. Conrad, James P. Eickhoff, Graham M. Harrison, May 2007

Over the past decade, considerable interest has emerged in replacing conventional fossil fuel-based polymers with bio-derived polymers. Two bio-derived polymers that have garnered significant interest are PHA and PLA. In this study, shear and extensional rheology, coupled with degradation studies using GPC, are used to investigate the flow properties of blends of these two polymers. The development of blends with tailored flow and thermal/mechanical properties is pursued.

The Effect of Long-Chain Branching on Extensional Rheoelogy and its Correlation as a Predictor for Molecular Architecture

Christopher D. McGrady, Donald G. Baird, May 2007

The effect of sparse long-chain branching on extensional rheology is analyzed for metallocene-catalyzed polyethylene resins with varying degrees of branching. The onset of extensional strain hardening distinguishes the degrees of branching while such distinctions are not apparent in shear flow behavior.

Mar Behavior of Thermoplastic Olefins

Robert Lee Browning, Han Jiang, Allan Moyse, Hung-Jue Sue, Edmund Lau, May 2007

Work has recently been conducted at Texas A&M University to evaluate the mar resistance of thermoplastic olefins using a modification of a currently established ASTM standard (ASTM D7027-05). This work strives not only to examine how the mar" is formed but also to illustrate the potential for this methodology to be established as a quantitative method for evaluating mar resistance of polymers. Approaches to improve mar resistance of polymers are also discussed."

Effect of Material Properties and Processing Conditions on PP Film Casting

Kenneth Aniunoh, Graham Harrison, May 2007

Film casting is a common industrial process used to produce polymeric films. The material properties and processing conditions have a significant impact on the process and the final thermal/mechanical properties. We experimentally investigate the impact of polymer molecular weight on the films. The effect of process conditions and post-processing steps like uniaxial stretching, on film strength, orientation and crystallinity is also studied. The measured velocity and temperature profiles are compared to model predictions.

Optimizing the Reaction Injection Molding Process using Polydicyclopentadiene

Nicole Hoekstra, Nate Slesinger, Luke Murphy, Jordan Keisser, May 2007

The variables that contribute to the processing difficulties of Polydicyclopentadiene (PDCPD) are many and not well understood. A screening designed experiment was run to determine the most vital of these variables. It was found that all of the variables had a significant effect on the mechanical properties of the PDCPD parts. A Central Composite designed experiment was then run to determine the optimum processing parameters including all of these significant variables.

Use of Injection Speed Profile to Achieve a Uniform Void Fraction Distribution in Injection Molded Structural Foams

John W.S. Lee, Jing Wang, Chul B. Park, Guoliang Tao, May 2007

The change in pressure drop and pressure drop rate at the gate of the mold during the structural foam molding process results in an inevitable nonuniform void fraction along the melt flow direction in injection molded structural foams. The nonuniform void fraction not only reduces the achievable void fraction but also can deteriorate the mechanical properties of structural foams. In this paper, an effort has been made to overcome this problem with various injection speed profiles.

Investigation and Modification of the Melt Rheology of Olefin Block Copolymers

P. Gupta, S. Costeux, T. Oswald, Y.W. Cheung, L. Weaver, S. Karande, S. Chum, May 2007

The melt rheology of novel Olefin Block Copolymers (OBCs), recently developed by The Dow Chemical Company, was investigated. The melt shear rheology of OBCs was found to be characteristic of linear random copolymers of ethylene and __olefins. Furthermore, the melt rheology can be modified to target certain specific application areas by chemical means or by blending with traditional polyolefins with broader molecular weight distributions or those containing long chain branching.

The Effect of Carbon Nanotubes on the Crystallization Behavior of Polyethylene Oxide

K.A. Narh, M. Khanolkar, S.M. Umbrajkar, E. Dreizin, May 2007

The effect of well-dispersed carbon nanotubes on the crystallization characteristics of polyethylene-oxide was studied. The specimens were prepared via the solution-sonication procedure. The results confirm the effectiveness of CNTs as nucleation agents for semi-crystalline polymers.

Fracture Behavior of Medium Density Polyethylenes by Essential Work of Fracture (EWF)

Johan J. Sánchez, María A. Navarro, Alejandro J. Müller, Orlando O. Santana, May 2007

The Fracture behavior of Medium Density Polyethylenes (MDPE) with different melt flow indexes (1.9 to 5.0 dg/min) employed in rotational molding were studied by Essential Work of Fracture (EWF). The EWF parameters obtained were equivalent for all samples examined regardless of their differences in comonomer content and molecular weights. Annealing of samples resulted in lower ductility values according to EWF parameters, in spite of minimum crystallinity changes.

A Parametric Study on the Processing and Physical Characterization of PLGA 50/50 Bioscaffolds

Linus Leung, Christine Chan, Janice Song, Billy Tam, Hani Naguib, May 2007

In this study, the effects of processing parameters on cell morphology and mechanical properties of PLGA 50/50 bioscaffolds for tissue engineering applications were investigated. The PLGA samples were processed using a salt leaching technique in a batch foaming setup. The foaming parameters were varied, and the physical and mechanical properties of the scaffolds were investigated.