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
Wasteless Distribution Medium: A New Development for the Resin Infusion Process
T. Wassenberg, W. Michaeli, May 2000
The typical resin infusion processes like SCRIMP (Seemann Composite Resin Infusion Molding Process) require the use of a distribution medium or system to increase the impregnation speed in large parts. Normally, a substantial amount of surplus resin remains in the distribution medium and has to be disposed with the medium or remains on the part as resin rich domains. A new patented type of resin infusion process is presented, which does not produce any surplus resin waste.
Welding of Polymers Using a Diode Laser
J. Schulz, E. Haberstroh, May 2000
Welding polymers by using a diode laser is a fairly new joining method. The first industrial application is the joining of automotive keys. The process advantages are precisely defined heated zones, minimized melt flow and the realization of three dimensional weld lines. At the IKV a process analysis has been done and the influence of pigments on the weld strength has been investigated. It is possible to weld glass fibre reinforced polyamide, which is transparent for the laser beam, but appears black to the human eye.
Elastomer Matrix Composites for Impact-Resistant Parts
M. Koschmieder, W. Michaeli, May 2000
The impact resistance and energy absorption capacity of most thermoset matrix composites is rather low. Use of elastomer matrix can improve the impact behavior, allowing the design of impact-resistant parts (e.g. crash elements). By using low-viscosity elastomer systems, composite parts can be produced on a commercial filament winding machine. Mechanical tests of filament wound samples show that elastomer matrix composites exhibit superior energy absorption behavior and offer a high optimization potential for impact-loaded composite parts.
Morphology/Property Relationships in Thermoplastic Starch/Poly(hydroxy ester ether) Biodegradable Blends
P.S. Walia, J.W. Lawton, R.L. Shogren, F.C. Felker, May 2000
The effect of moisture level during processing on the mechanical properties of biodegradable blends of thermoplastic starch and poly (hydroxy ester ether) (PHEE) was studied. The morphology of the blends changed with the moisture content of starch. The dispersed phase was significantly deformed under high moisture conditions, leading to fibrillar and laminar types of morphologies at 50-80% starch level. A low moisture level produced a more dispersed morphology. Improved tensile properties were observed for the blends processed at high moisture levels due to the presence of elongated morphologies.
Mechanical Properties of Starch Filled Poly(hydroxy ester ether) Biodegradable Composites
S. St. Lawrence, J.L. Willett, C.J. Carriere, May 2000
The mechanical properties of starch filled biodegradable composites have been investigated. The strength was found to be independent of the filler content below 10 vol% and above approximately 30 vol%. This behavior is due to the failure mechanism operating in these composites. The matrix, poly(hydroxy ester ether) (PHEE), adheres well to starch and as a result the granules do not dewet during deformation. Instead the composites behave as a quasi-homogeneous material with increased brittleness as the filler content increases. The deformation mechanism was investigated by acoustic emission analysis and by a post-mortem examination of the fracture surfaces.
Mold-Making Apprenticeship Program in Georgia
William T. Thielemann, May 2000
This paper will trace the development of the Mold-Making Apprenticeship Program in Georgia's technical institutes, developed to support the plastics industry within the state. It will explain why the program was developed, how it was developed, the content of the program and the results to date. The purpose of the poster presentation is to explain the process and outline the program with the goal of assisting other states with similar programs and ultimately addressing the shortage of trained and available mold-makers. The poster presentation will include three sections: industry growth and potential, team process and program outline.
Regulatory and Experimental Approaches to FDA Food Contact Compliance
Robert L. Pesselman, Melanie McCort-Tipton, May 2000
Tests to determine the migration of indirect additives into actual foods are essential in order to ensure food safety. Recent changes in regulatory protocols and evolving analytical technologies have helped define new ways to receive regulatory clearance for food contact polymers. This poster summarizes the issues to be addressed when designing a test plan and outlines regulatory considerations and experimental approaches applicable to both Food and Drug Administration (FDA) and European compliance. In addition, the proper use of food simulants, available extraction cells, and analytical techniques are discussed.
Profit from Recycling Tooling and Leadership Change
Wilhelm O. Morgan, May 2000
This paper is about upgrading tooling that has been built many years ago, or simply to make mouldings to suit our type of manufacturing operation. When these tools were built the techniques and technology used was the latest available to the polymer technologist designer, mould shop and toolmaker. Using tooling technologies as the starting point, I have added management, and more so Leader techniques to show how production can be changed and opportunities gained, by modernising; towards increasing production, saving money, material, and bringing about attitudinal changes. This paper will concentrate on the following topics, and show details where this revisiting process has changed tools and people to make them more motivated about competition, which will result in profitable, faster cycling and be better suited to today's fast operational needs.
Wood Flour Reinforced Polystyrene Composite Using SEBS-g-MA as Compatibilizer
Chen-Jui Hung, Jenn-Fong Kuan, Jaine-Ming Huang, May 2000
A functionalized thermoplastic elastomer, SEBS-g-MA (styrene-ethylene-butadiene elastomer grafting maleic anhydride), has been demonstrated to be an effective compatibilizer in polystyrene-wood flour composite and results in the formation of an in-situ formed copolymer existing between the interface of polystyrene and wood flour and thus enhance the interface adhesion and mechanical properties of the composite. With the addition of SEBS-g-MA, both flexural modulus and impact strength of polystyrene-wood flour composite has been improved substantially and a good interaction between polystyrene and wood flour can be indicated by Scanning Electron Microscopic (SEM) images as well. The result shows that composite with 4phr SEBS-g-MA gives the optimum mechanical property.
Characterization of Multi-Layer Permeation Barriers Made by Microwave Plasma Polymerization
R. Dahlmann, W. Michaeli, May 2000
Plasma polymerization is a suitable process to deposit high quality permeation barrier coatings on plastics substrates. The process allows to stack several layers forming multi-layer coatings. In these studies, the permeation properties of single- and multi-layer coatings made by plasma polymerization are investigated. As a result, the oxygen transmission through multi-layers does not only depend on the structures of the single layers. Also, the arrangement of the layers shows great effect on the permeation properties.
Recycling PVB Automotive Windshield Interlayer
Robert S. Boyd, Daniel M. Sullivan, May 2000
PVB (polyvinyl butyral) windshield interlayer retains physical properties very well, owing to being effectively packaged in glass prior to recycling. However, the cost of removing all of the contaminant has precluded PVB's acceptance in many applications where it might, otherwise, have been usefully recycled. We have found that finely pulverizing the scrap, with its attendant residues, allows melt-process manufacture of products meeting automotive requirements for vibration damping, tensile strength, tear resistance, and flexibility, over a wide range of temperatures.
Adding Value to Rotational Moldings with Color and Special Effects
Nick Henwood, May 2000
This paper reviews the different ways of adding color in rotational molding and provides technical and economic arguments for each method. The effects of pigment incorporation on base material properties are discussed and the importance of factors such as pigment type, pigment loading and method of mixing are examined in relation to material processing, physical properties and the aesthetics of the final rotomolded part. The use of special effects such as stone and antique look colors to give further value enhancement is discussed.
Dispersion of Nanoscopic Clay Particles in Thermoplastic Polymers
Grant D. Barber, Christopher M. Carter, Robert B. Moore, May 2000
The formation of clay nanocomposite, hybrid materials will be achieved through the incorporation of organically modified montmorillonite clay particles within a variety of thermoplastic polymers. In order to facilitate a homogeneous dispersion of the clay nanoparticles in the thermoplastic matrix, ionomeric compatibilizers will be utilized. The matrix polymer/ionomer pairs chosen for this study include polystyrene/sulfonated polystyrene, PET/sulfonated PET, and polypropylene/carboxylated polypropylene. Various methods of clay dispersion, including melt-processing, in-situ polymerization, and solution-state mixing will be utilized and compared. The morphology and physical properties of the resulting nanocomposites will be investigated using SAXS, TEM, DSC, TGA, DMA and standard tensile test methods.
Modeling Residual Stresses in Thermosetting Materials
Patricia Prasatya, Gregory B. McKenna, Sindee L. Simon, May 2000
The residual stresses in a composite subjected to three-dimensional constraints are calculated by extending a thermo-viscoelastic model developed previously by Simon et al. [1] to describe the time, temperature, and conversion dependence of the shear modulus for a commercial thermosetting material during cure. Experimental residual stress data as a function of cure are fit to obtain limiting values for the rubber and glassy bulk moduli. The residual stresses are then calculated as a function of cure history using the bulk moduli and the time function obtained in the thermo-viscoelastic model which include the dependence of the shift factor on temperature and conversion.
Crack Propagation in Continuous Glass Fiber/Polypropylene Composites: Matrix Microstructure Effect
M.N. Bureau, J. Denault, F. Perrin, J.I. Dickson, May 2000
The crack propagation behavior of a unidirectional continuous glass fiber/polypropylene (GF/PP) composite with two different matrix morphologies was studied. Changes in the matrix morphology obtained by varying the cooling rates during the molding process resulted in changes in: 1) the flexural strength and strain at failure using three-point bending specimens; 2) the critical strain energy release rate in mode I quasi-static crack growth using double-cantilever beam (DBC) specimens; 3) the fatigue crack growth rates at given levels of strain energy release rate in mode II fatigue crack propagation using end-notch flexure (ENF) specimens. The reduced presence of the ductile amorphous PP phase in the PP/GF composite at lower cooling rates is responsible for the reduction in mechanical performance.
Spectroscopic Studies of Ion Implanted Polycarbonate
James M. Sloan, May 2000
Ion implantation is a process by which ions are accelerated and focused at a rapid speed to a target at energies high enough to bury them just below the target's surface. These ions penetrate the sample surface and form a thin layer below the surface. Until recently this technique was mainly utilized for modification of semiconductors (1) or to improve wear characteristics in metal tooling and polymers (2,3). Now the use of ion implantation has been extended to polymers. Improvements in adhesion (4), electrical (5) and abrasion (6) have been reported. The resulting chemical effect of ion implantation in polymer systems is to increase chain scission and cross-linking., while decreasing crystallinity(7). In this study, the effects of medium energy ion implantation of boron, nitrogen and fluorine into a polycarbonate matrix was examined by Fourier transform infrared spectroscopy and UV/VIS spectroscopy. The implanted polycarbonate linkage degrades upon implantation. Further implantation leads to carbonization just below the surface of the specimens.
Optimization of Composition of Soy-Based Polyols for Rigid Polyurethane Foams
Ivan Javni, Zoran Petrovic, Wei Zhang, Andrew Guo, May 2000
Soybean oil-based polyols can be synthesized with different OH content. Higher OH number polyols display higher viscosity, which may limit their applications in foams. Adding glycerin to a polyol affects crosslinking density and homogeneity of the networks. It would be advantageous to use a lower OH content and a lower viscosity polyol and adjust the OH number with glycerin if the properties would stay the same. Apart from having lower viscosity, polyols with lower a OH number are easier to prepare. It has been shown that rigid foams based on the polyol having an OH number of 180 mg KOH/g have similar properties as those based on the polyol with an OH number of 208 mg KOH/g if the final OH number of the polyol system (polyol, crosslinker and water) is adjusted to the same value, although heat stability (onset of softening) of the former was lower.
Some Reasons Not to Use Multi-Cavity (>4) Tools
John W. Bozzelli, May 2000
Injection molding continues to be the preferred plastic process for making large quantities of plastic parts. The goal is to make identical parts. When parts are not identical problems develop, not just in performance but also in assembly. The trend toward more complex parts, coupled with demanding tolerances continues to challenge processors in pursuit of the goal of identical parts. Reasons against the trend for high cavitation molds are proposed.
Polymer Melt Flow Behavior in the Coinjection Molding Process
K.T. Nguyen, E. Turcott, A. Derdouri, D. Ait Messaoudz, B. Sanschagrin, B.A. Salanton, K.A. Koppi, May 2000
An experimental study of the co-injection molding process was carried out. The fingering instability due to the difference in viscosities of the two materials gave rise to early breakthrough of the core material and non- uniform skin layer thickness. The core material was also used as tracer material for flow visualization of the injection molding process. The V formation near the wall as well as the mushroom effect, previously predicted, was observed.
Relative Dimensional Change of Various Nylon Products Due to Moisture Absorption
Steve Gerbig, Bonnie Richter, Brian Helfrich, May 2000
In plastic materials published data, moisture absorption is almost always expressed in terms of percent weight gain. While this information is important for comparison purposes, it doesn't truly relate to the design engineers' application and use of these materials. This study will quantify and compare the relative dimensional changes which occur in parts as they are exposed to a humid environment and move from the dry-as-molded state toward saturation using nylon types 6, 66 and 46.
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