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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Effects of Molding Conditions on the Quality of Electroplateable PC/ABS Parts
The effects of injection molding conditions on the quality of electroplated parts were examined for a plateable polycarbonate/poly (acrylonitrile-butadienestyrene) (PC/ABS) blend. Melt temperature, mold temperature, injection rate, and pack pressures were varied using a design of experiments. The tensile, flexural, and impact properties of the parts were measured using standard test methods. Surface composition was characterized using dye absorption. Electroplating results and mechanical properties were correlated with the migration of polybutadiene within the molded parts.
Layout Design of a Platenless Molding Machine
A layout design of a platenless injection molding machine is developed. The machine design is motivated by economics, energy efficiency, compactness, ease of use, and environmental friendliness. The elimination of traditional platens allows for significant performance improvements as well as flexibility of new injection system and mold designs. This paper establishes theoretical feasibility, but also indicates that the design is most appropriate for clamp tonnages less than 150 tons due to actuator power and mold deflection limitations.
Validation of Flow Simulations for Micromolded Parts
For a micro molded part, the fill patterns predicted by commercial flow simulations were comparable to short shots from molding trials. The fill patterns were significantly affected by the analysis type, particularly the use of three-dimensional flow and heat transfer. Meshing of the models, specifically in the gate region also influenced filling results. While material type affected the fill pattern, molding conditions, including injection rate and melt temperature only determined whether the part would fill.
Influence of Geometric Shape of Void on Mechanical Properties of Polyurethane Foam
We attended to the void evaluation of polyurethane foam materials. Several kinds of foam materials with different foam states were employed. Images of cross section were scanned in the computer. Void feature was extracted as white pixels by binary image. The algorithm of extraction for geometric information of void was examined. The shape and the size of void in the foaming direction were clarified, and the correlation with mechanical properties was associated.
Characterization of Ethylene Vinyl Acetate/Montmorillonite Nanocomposite
Intercalation/exfoliation behavior and mechanical properties of ethylene vinyl acetate copolymer/monmorillonite nanocomposite are investigated as a function of vinyl acetate content and compatibilizer. XRD and tensile tester are used to characterize the nanocomposites. The results show that intercalation/exfoliation behavior and mechanical properties of nanocomposite are strongly depending on the vinyl acetate content and compatibilizer.
Influence of Temperature on Surface Tension of Three Liquid Crystal Polymers and Polyethylene Teraphtalate
In this work Pressure Volume Temperature (PVT) data for different liquid crystal polymers (LCPs), (Vectra™ A950 and based on 4,4'-dihydroxybiphenyl (PB-n)), and polyethylene teraphtalate (PET), were obtained. The experimental data were used to predict the influence of temperature on the surface tension of the materials studied.The surface tension of PET was shown to decrease linearly with increasing temperature. A clear discontinuity was observed for both ?PB-8 and ?PB-11 near the mesophase to isotropic transition.
Multiple Percolated Co-Continuous Polymer Blends
In this paper, high-density polyethylene, poly (methyl methacrylate) and polystyrene are blended at a certain composition to form a multiple percolated co-continuous morphology. HDPE and PMMA form a co-continuous structure in which the PS phase layers and forms a sheath structure on the surface of the PMMA. This structure forms spontaneously during melt mixing and is predicted from spreading coefficient theory.
Dynamic Modeling for the Deformation and Breakup of Agglomerates in Polymer Melts
A dynamic predictive model of the breakup process of agglomerates is developed by taking into consideration the hydrodynamic forces and the particle-particle interaction forces which induce flocculation in polymer melts. The breakup process of coagulated particles is numerically investigated by using the Discrete Element Method (DEM). The proposed DEM model we have developed describes the breakup phenomena, such as erosion, rupture, and coalescence, of agglomerates adequately in the various flow fields.
Mechanical Modeling and Surface Characterization of Scratch in Polymers
In this paper, fundamental scratch behavior of polycarbonate (PC) was studied. Scratch tests were performed using a custom-built scratcher with a steel ball tip. Effects of scratch rates and loads on the damage phenomena in PC were investigated. Finite element (FE) modeling was executed to give a better understanding of the scratch deformation on polymers. Correlation between the FE and experimental results will be discussed. Extension of the present research to other polymers, like PMMA and TPO, will be presented.
The Development of High Melt Strength Polypropylene Using the Reactive Extrusion Process
HMS-PP (High Melt Strength Polypropylene) was produced by using a 50 mm twin-screw extruder. This HMS-PP had a high strainhardening index enough to make stable foam cells and have no gels of cross-linked polypropylene. In this study, we used a mixture of polypropylenes having different MFR (melt flow rate) and a small amount of IPP (iso-propyl peroxydicarbonate) to get a high efficient HMS-PP. In addition to it, this HMS-PP was non-toxic because it was not made with an additional reactive monomer.
Processability Studies on Polycaprolactone and Polybutylene Succinate Foams
Two commercial biodegradable polymers, polycaprolactone and polybutylene succinate, were used to study their processability in crosslinked foam processes. Benzoyl peroxide and t-butyl perbenzoate were used, respectively, to initiate crosslinking reactions. Zinc diacrylate was used to enhance the gel content of the crosslinked polymers. The change in melt strength of both polymer systems was assessed by measuring their dynamic mechanical properties. The effects of crosslinking agents and coagents on foam densities and gel contents are also reported.
The Quaterrylimides - Highly Efficient NIR Absorbers for Plastics
A couple of years ago we developed a class of highly efficient organic NIR absorbers based on quaterrylenetetracarboxylic diimides ('quaterrylimides'), which exhibit photo- and thermostabilities at levels hitherto reserved exclusively to inorganic materials. In this paper we want to present models for the explanation of the unique photostability of this class of compounds, as well as recent advances in the synthesis of those materials, and examples for state-of- the-art plastics applications.
Modeling for Compaction of Particulate Materials
Compaction of powders has been used in manufacturing of components for a broad range of application. In this paper compaction data for pure particulates and composite mixtures as well as mathematical models are presented. The model could successfully be used not only for metal powders but also for polymer and ceramic powders and/or their composite mixtures in order to predict their compaction behavior as a function of temperature and speed.
A Study of Nano-Titanium Dioxide Dispersed in PBT
A countercheck of dispersion effect by different types of dispersing agent and different shear stress of screw design has been investigated. Low shear one, not as we originally expected, showed a much more stable head pressure, which is an important parameter to monitor fabric extrusion, than a higher shear screw design. TGA was furthermore applied to confirm the weight loss after every single test.
Effect of Compatibilizer Concentration on Properties of Polypropylene-Clay Nanocomposites
Polypropylene/Montmorillonite nanocomposites were prepared by melt compounding with different concentrations of the compatibilizer, which is a maleic anhydride grafted polypropylene, using a reactive twin-screw extruder. They were characterized using tensile testing, DSC, XRD and TEM. It was found that beyond a certain concentration of the compatibilizer, the mechanical properties deteriorated. This was explained on the basis of shear rate-viscosity relationships and the nature of interfaces governing the nanocomposites.
PMMA/Laponite Nanocomposites Prepared by Melt Compounding
Nanocomposites using PMMA and Laponite were prepared by melt processing in a reactive twin-screw extruder. The clay particles were dispersed in an aqueous medium before being mixed with PMMA. Polymer nanocomposites were prepared at different solids (clay) loading and samples were characterized using wide-angle x-ray diffraction, TEM, as well as stress-strain measurements, DSC and Nanoindentation. One of the nanocomposites was almost as transparent as pure PMMA and exhibited better mechanical properties than pure PMMA. Results will be presented and discussed.
Effect of Interphase Condition on Mechanical Properties in Polyamide Pre-Impregnated Glass Fiber Reinforced Polypropylene Composite
In order to improve the mechanical properties of glass fiber reinforced polypropylene composite, the polyamide pre-impregnated glass fiber is candidate. The pre-impregnated resin distributed near the glass fiber and it would affect both the fiber length in molding and the interfacial properties. Consequently the tensile strength could be improved.
Effect of Gate Design when Molding Thermoplastic Elastomers
The depth, width and land length of an edge gate were systematically varied in order to assess guidelines for gates used in injection molding of thermoplastic elastomers (TPEs). Each gate design was evaluated using several classes of TPEs and a range of processing conditions.
Clay Nanocomposites in a Combustible Molded Material
Flame retardant compounds are commonly used in industry. In this study, clay nanocomposites will be evaluated for their effectiveness to control combustion. The clay nanocomposites will be incorporated into the resin through injection molding. The effectiveness of the different percentage of nanocomposite will be compared using traditional flame retardant evaluation techniques and their ability to control combustion on the outside of the polymer.
The Effects of Pack Velocity on the Injection Molding Process
With the introduction of electric molding machines and upgraded technology, in molding, an un-developed part of the molding cycle is introduced; this piece of the cycle is known as pack velocity. This study will demonstrate how to set and optimize the pack velocity. The optimization is be evaluated by studying the effects of pack velocity on part weight (density), and part dimensions.
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