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

Comparative Performance and Barrier Properties of Biodegradable Thermoplastics and Nanobiocomposites vs. PET for Food Packaging Applications

D. Cava, A. López- Rubio, L. Cabedo, E. Giménez, J.L. Feijoo, R. Gavara, J.M. Lagaron, May 2005

This paper reports about the comparative behaviour, regarding PET, of biodegradable biopolymers such as PCL, PLA and PHBcoV and their nanobiocomposites, in terms of thermal and retorting resistance (thermal humid processes) and oxygen, water vapour and aroma barrier by means of time-resolved synchrotron radiation, FT-IR and permeation methods.

Drawing Forces and Film Properties in Semi Sequentially Stretched Polypropylene

Michael A. McLeod, May 2005

The relationship between biaxial stretching kinematics and oriented polypropylene film properties was studied. Initially only transverse direction (TD) speed was varied while areal draw ratio and machine direction (MD) speed were held constant. Slow TD speeds increased final TD drawing force and produced anisotropic film shrinkage. Tensile properties were primarily a function of draw ratios. Using different MD and TD draws allowed tensile properties to be changed while holding film shrinkage nearly constant.

Melt Fracture Analysis Using an In-Line Camera

Michael A. McLeod, May 2005

A low melt flow rate metallocene isotactic polypropylene homopolymer was cast into film with and without melt fracture. Using an in-line camera, melt fracture was quantitatively described using real-time measurements of film defects. Melt fracture caused more variation in light transmittance, leading to a higher defect count. This measure of film optics was more sensitive to melt fracture than haze or gloss.

Scratching Behaviors in Injection Molded Products

Machiko Mizoguchi, Takashi Kuriyama, Hiromi Kita, May 2005

Scratch behaviors of injection molded products, such as PS, HIPS, ABS, PC/ABS, were investigated. From the observation by optical microscopy of scratch, the damages generated were understood. They depended on the types of polymers and the structure near the surface generated during the injection molding. The scratch behaviors would be affected by friction between the polymers and scratch tip and modulus, yield strength, fracture toughness of the polymers.

Fast Simulation Methodology and its Application in Injection Molding

Shen Changyu, Yu Xiaorong, Li Qian, May 2005

The injection molding is a popular technique of polymer processing, which multiple parts with tight tolerances and complex shape can be produced in a single operation. Through studying the flow behavior of melt in cavity and runner system, a fast flow simulation method is developed based on the introduction of the equivalent flow length concept. The optimization algorithms and fast flow simulation technology are integrated to optimize gate design.

Morphology of PC/ABS Blend Systems Fabricated by Injection Moldings

Machiko Mizoguchi, Takashi Kuriyama, May 2005

Morphology of PC/ABS injection moldings was observed by TEM in parallel to flow direction and transverse. The thin films, which thickness was less than 100 m, of PC and ABS were observed near the surface with regardless of injection speed, while ABS was in fibrous shape at the center. The geometry of butadiene rubber domains creating salami occluding SAN was a focus. It is confirmed that they elongated in flow directions.

An Approach to Gradation Mesh Generation in Injection Molding Simulation

Xiao-Dong Yang, Chang-Yu Shen, Chun-Tai Liu, Jing-Bo Chen, May 2005

Based on advancing-front method and Delaunay triangulation concept, a new interior point generation scheme is proposed. The longest edge at the current advancing-front is always chosen to create a new triangle element by using Delaunay triangle’s property, so that a high-quality graded mesh is obtained and a smooth transition in element size is maintained. The high-quality mesh can make plastics injection molding computer simulation more precise.

Influence of Clay Orientation and Aspect Ratio on Morphology and Mechanical Properties of Nylon-6/Clay Nanocomposites

J.-I. Weon, H.-J. Sue, May 2005

The influence of clay orientation and aspect ratio on morphology and mechanical properties of nylon-6/clay nanocomposites is investigated. Our findings suggest that clay orientation can affect the nucleation and orientation of crystalline lamellae of nylon 6 matrix. The presence of clay also hinders the relaxation of nylon matrix during annealing. Consequently, clay aspect ratio and orientation can greatly influence the overall morphology and mechanical properties of the nanocomposite.

Novel Dynamic Nucleation Theory for Microcellular Plastics

ZHOU Nan-qiao, ZHU Wen-li, PENG Xiang-fang, ZHANG Zhi-hong, May 2005

Polystyrene microcellular plastics blown with supercritical carbon dioxide were prepared by novel electromagnetic dynamic foaming simulator. Bubble nucleation processes in stable and dynamic shearing flow field were analyzed. The experiments showed that after imposing vibration, cell size decreased and cell density increased. The key issue with dynamic nucleation is that the shear energy generated by mechanical vibration improved bubble nucleation. Novel dynamic nucleation theory was put forward from the viewpoint of shear energy in this paper.

The Effects of Runner Diameter and Cavity Size on Packing a Part in Injection Molding

Christopher Welsh, Christopher Stewart, May 2005

This paper presents the study which challenges some of the classic theory regarding runner sizes as related to packing. This study has found that, in some cases, packing control can be maintained with runner diameters which may be as small as, or even smaller than, the wall thickness of the parts being molded. This study further showed that in some cases, increasing cavity size allowed for improvements in packing control. Both of these findings are contrary to the classical wisdom used for today’s runner designs.

Performance of a Machine Augmented Composite

J. Kim, T.S. Creasy, G.F. Hawkins, M.J. O’Brien, May 2005

An advanced machine augmented composite was fabricated and tested. This composite is composed of rigid polyurethane machines with pre-buckled walls as a reinforcement and soft polyurethane as a matrix. Dynamic properties of the composite were measured in the frequency of 0.1 ~100 Hz range at room temperature by load-controlled cyclic testing. Measured tan ? values and loss modulus showed noticeably higher values than the matrix did at the frequency range of 0.1~ 40 Hz.

The Criss-Cross Die

Stephen J. Derezinski, May 2005

The typical center-fed manifold-die has a pressure at the center higher than at the edges that gives rise to an uneven flow distribution. This is eliminated by the crisscross die, which has two end-fed manifolds with half-flows in opposing directions. One half-flow has a pressure gradient equal and opposite to that of the other. The two opposed half flows and pressure gradients combine in a main delivery manifold to create a uniform pressure across the width of the die. The result is a die that produces extremely uniform widthwise flow for use in sheet manufacture and coatings.

Dielectric Properties of Graphite Nanocomposites

Shing-Chung Wong, Erwin M. Wouterson, Eric M. Sutherland, May 2005

Polymer nanocomposites are an emerging class of multifunctional materials that have not been optimized for their functional potential. In this study the dielectric properties of graphite polymer nanocomposites were evaluated. The objective is to develop an alternative costeffective nanoscale carbon material with comparable properties like carbon nanotubes for composite applications.

Barrier Liner Material with Nanocomposite for Packaging Applications

Anatoliy Ya. Goldman, May 2005

Plastic containers for beer, juice or CSD require matching plastic closures. Recently we developed a multi-layer barrier liner with nanocomposite that inhibits ingress of O2 and egress of CO2, into and out of the container. A passive barrier layer of Nylon nanocomposite and one or two reactive layers with scavengers are included in multi-layer structures. The multi-layer liner material with nanocomposite and reactive layers perform better than other barrier materials at very high relative humidity.

Characterization of Virgin/Recycled Nitrile Rubber Blends

M.A. García, M. Hernández, M. Ichazo, J. González, May 2005

Blends of Virgin and Recycled Nitrile Rubber within a blend ratio of 10-30 %wt recycled NBR were studied. Reference was made to mechanical and physical properties. Results obtained indicate that a maximum percentage of 20%wt recycled rubber can be added to a NBR formulation without diminishing considerably final properties, since higher percentages promote a premature vulcanization. Concerning chemical resistance, an excellent oil resistance and a very low resistance to polar solvents were obtained for all formulations.

Predictive Damage and Failure Modeling for Composites Made of Baypreg®-F

James M. Lorenzo, May 2005

As composite structures become more commonplace, advanced finite element analysis routines are required to accurately predict their structural performance. To aid design engineers, a simple damage and failure model for multi-laminate, anisotropic composites is evaluated for the prediction of stiffness and strength behavior. Results from the model are compared to experimental data.

Factors Affecting Single Screw Extrusion Output Rate of Thermoplastic Vulcanizates (TPVs)

Oansuk Chung, May 2005

Factors affecting the output rate of TPVs in a single screw extruder are investigated. The factors examined in this study include extruder rpm, barrel temperature, TPV pellet temperature, and TPV material selection. Process optimization is demonstrated for maximum output rate in a safe operating condition. The fundamental extrusion mechanism of TPV is discussed in contrast to that of other polyolefin resins.

Modeling the Interaction of Glass Yarns with Molten Plastic in the Cable Extrusion Process

Ming Li, Ashwini Kumar, Jaydeep Kulkarni, May 2005

We present a cable extrusion study that involves flow around a deformable moving fiberglass strand inside a cable extrusion die. In addition to non-Newtonian rheology, the fluid-structure interaction (FSI) between the polymer melt and the moving strand is highly non-linear. Using computational fluid dynamics (CFD), we have gained insight of our extrusion process by studying the strand deflection, the strand speed and the strand tension. The numerical results showed value in guiding the extrusion process.

The Effect of Crosslinking on the Mechanical Properties of PLA/PCL Blend

Takeshi Semba, Kazuo Kitagawa, Umaru Semo Ishiaku, Hiroyuki Hamada, May 2005

The improvement of brittle behavior of PLA resin was studied by blending it with PCL resin. Peroxide (DCP) was added in order to form co-cross linked structure at the interphase. These materials were blended, and they were fabricated into thin films. DCP content was varied accordingly (0, 0.1, 0.2, 0.3, 0.5, 1, 2phr). The value of ultimate strain peaked at 0.1 and 0.2 phr DCP contents, but it was low at higher DCP content. It was thought that the peak changes of FTIR denote the compatibility at the interphase.

Foam Extrusion of Linear Polyolefins by Lightly Cross-linking

Chung P. Park, May 2005

Linear polyolefin resins, which are difficult to foam by extrusion, have been successfully expanded to good-quality foams by lightly crosslinking the resins with an azido-functional silane or peroxide.