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
Effect of Surface Treatment on the Interfacial Interactions and Impact Properties of Calcium Carbonate Filled Polypropylene Composites
Yeh Wang, Wei-C. Lee, May 2002
The present study investigated the effects of surface treatment on the surface properties of calcium carbonate and on the interfacial interaction between filler and matrix. An extensive comparison was made on the efficacy of the surface treatment between stearic acid, a non-reactive surfactant, and LICA 12, a reactive coupling agent. The change in surface properties due to surface treatment was characterized through inverse gas chromatography (IGC) at infinite dilution. The stearic acid treated filler showed lower dispersive and polar components of the surface energy than LICA 12 treated system for completely coated CaCO3 fillers. Infrared analysis demonstrated that stearic acid reacted extensively with the filler surface to produce organic salt compound. Izod impact strength was measured on sharp-notched samples. It was found that stearic acid treated composites exhibited greater impact strength than LICA 12 treated systems.
Effect of Thermoplastic Elastomer Material Properties on Mold Filling Imbalances
Patrick Auell, Michael Bailey, May 2002
Significant shear induced filling differences are commonly seen between cavities in multi-cavity injection molds. These filling variations can be particularly important when over-molding TPEs on delicate plastic inserts. This paper compares the amount of imbalance detected when molding different grades of TPEs. It then evaluates the relationship of the materials shear, temperature, and viscosity indexes on the magnitude of shear-induced mold filling imbalances to determine which factors most directly influence this imbalance. This understanding will help a molder more readily predict and address the problem. Furthermore, the study evaluates the use of melt rotation technology (1) to minimize the imbalances.
Effect of Viscosity on Low Density Foaming of Poly(Ethylene-Co-Octene) Resins
Caroline Vachon, Richard Gendron, May 2002
Foaming of low density poly(ethylene-co-octene) resins by injection molding is the result of various reactions occurring during the process. This includes simultaneous decomposition of the chemical blowing agent and cross-linking of the polymer matrix during curing in the mold, followed by foaming after mold opening. Dynamic rheology as well as elongational viscosity were investigated for compounds prepared from resins with different MFIs and various cross-linking agent levels, and these results were linked to the morphology and density of the corresponding foams. Rheological requirements were finally defined quantitatively for this set of conditions.
Effect of Viscosity Ratio on Co-Continuity for Ethylene-Propylene-Diene Terpolymer/Polypropylene Blends
Prashant A. Bhadane, Basil D. Favis, Michel F. Champagne, Michel A. Huneault, Florin Tofan, May 2002
Blends of ethylene-propylene-diene terpolymer (EPDM) and polypropylene (PP) of significantly different viscosity (torque) ratio (T.R.) were prepared in an internal mixer (Haake) over the entire range of composition. The torque of the blends as well as the torque of the pure materials were noted and compared.For the 0.7 viscosity ratio blend, SEM micrographs showed very fine dispersed particles of EPDM of size 50 to 200 nm in the low composition range of EPDM. For the 10.0 viscosity ratio blends the particle size ranged from a few hundred nanometers to a few hundred micrometers at low compositions of EPDM.Also according to solvent gravimetric data and SEM micrographs we find that, the 0.7 viscosity ratio blend demonstrates the onset of percolation at a composition of 30% EPDM and reaches 100% continuity at 60% EPDM. In contrast, the 10.0 viscosity ratio blend showed no continuity at 20% EPDM and attained 100% continuity at a composition of 30% EPDM.
Effects of a Diamond-Like Nano-Composite Coating on an Injection Blow-Molding Machine Core Rod
Mark K. Gutman, Justin M. Page, May 2002
The study being conducted tests the effects of a coating on a core rod for an injection blow-molding machine. The coating is different than the standard chrome plating. The coating on the core rod is the ART Dylyn® R, which is a diamond-like nano-composite material. Through this study, we will determine the effect this coating will have upon friction and thermodynamic properties of the core rod. The significance of this experimentation is to find advantages and disadvantages of the coating. Our goal is to find the effects it will have on the overall part quality. We ran a Design Of Experiments (DOE) on both the coated core rod and the standard core, on an injection blow-molding machine. Following the experiments, analysis of the data, which includes, wall thickness, force, and pressure, will be interpreted.
The Effects Colorant Particle Size on the Mechanical Properties of Polycarbonate Resin
Damon DeVore, Joseph Latchaw, Carl Caldwell, May 2002
Polycarbonate resins are utilized in many engineering applications that require stable mechanical properties in a wide range of colors. The colorant itself may have an effect on the outcome of the mechanical properties of the final resin compound. If the particles that make up the colorant additive vary in size, this could possibly cause a variation in the mechanical properties of parts molded from the resin, much like the effects of molecular weight distribution in a polymer.This research studied the effects of the mean particle size distribution of the colorant to determine if the particle size does indeed have an affect on the resins mechanical properties.
Effects of Additive and Polymer Architecture on Antiplasticization of Model Epoxy Networks
Adam S. Zerda, Alan J. Lesser, May 2002
A new class of antiplasticizers is investigated for epoxy-based crosslinked polymers. In order to elucidate the mechanisms for antiplasticization of epoxy thermosets, effects of additive chemistry and network architecture are considered. Both model and commercial epoxy networks are studied, probing the effect of molecular weight between crosslinks. Additionally, the family of phosphates being studied ranges in molecular weight and density which are shown to strongly influence the degree of antiplasticization. Mechanisms of antiplasticization are discussed.
The Effects of Compounding Conditions on the Properties of a Polypropylene/Polyamide-6 Blend
Bhavjit S. Ghumman, Stephen A. Orroth, Carol M.F. Barry, May 2002
This study examined the effects of compatibilizer type, screw design, screw speed, melt temperature, and water content on the properties of TPO/polyamide-6 blends compounded on a co-rotating twin-screw extruder. Temperature had the greatest influence on the mechanical properties of the resultant blends with higher temperature causing a severe reduction in properties. Higher screw speeds also decreased properties due to shorter extruder residence time. The effect of screw design depended on the strength of the compatibilizer. For this system, a polysiloxane compatibilizer provided more effective dispersion than maleated polypropylene, but was sensitive to moisture content in the polyamide-6.
Effects of Conductive Particles onthe Strength of Adhesion between Conductive and Non-Conductive Polymer Compounds
Chang Min Hong, Sadhan C. Jana, May 2002
Articles with surface conductive layers molded onto virgin polymers provide mechanical strength of virgin polymers and sufficient surface conductivity with small amounts of conductive particles, thus obviating the needs of molding the whole articles from conductive polymer compounds. Multi-layer molding methods, such as co-extrusion, injection-compression, compression molding, etc. can be used provided the adhesion between conductive and non-conductive layers is strong.This paper describe the effects of particle concentration and polymer molecular weight on the strength of adhesion in carbon black-filled polypropylene as measured by peel test and from changes in complex shear modulus of conductive/non-conductive sandwich compounds.
Effects of Cooling Rate on the Mechanical Properties of Rotationally Moulded Polyethylene Parts
N. Callan, M.P. Kearns, M. Spencer, R.J. Crawford, May 2002
It is well known that the rate of cooling has a major effect of the dimensions and shape of rotomoulded plastic parts. There is also qualitative evidence that the mechanical properties are affected by the cooling method. This paper will quantify the effects of the cooling rate on the microstructure and mechanical properties of rotationally moulded polyethylene parts. A variety of cooling profiles were used, including external forced air, water-cooling and internal part air-cooling. Differential Scanning Calorimetry was used to measure the degree of crystallinity throughout the cross-section of the mouldings and this information is correlated with the toughness of the mouldings as measured by falling weight impact tests.
Effects of Fiber Orientation upon the Electromagnetic Shielding of Injection Molded Liquid Crystal Polymers
W.S. Jou, T.L. Wu, S.K. Chiu, May 2002
The shielding effectiveness (SE) of liquid crystal polymers (LCP) composites with longitudinal fiber orientation is higher than that with random fiber orientation under the same weight percentage of carbon fibers filled because that longitudinal fiber orientation is parallel to the electric field of incident EM wave. The fiber orientation was controlled by two kinds of gate locations and the samples were injection molded. The shielding effectiveness of 20% conductive carbon fiber filled liquid crystal polymers composites were measured to be 50 dB at frequency of 0.3 GHz and 53 dB at 1 GHz.
Effects of Hygroscopic Properties on Weld Line Integrety of Tensile Specimens of High Temperature Glass Reinforced Nylon
Robert M. Belz, Eric Lingle, May 2002
Weld lines are present in many plastic components throughout the world. Avoiding weld lines is almost impossible, so knowing the effect they have on the physical properties of plastic structures is extremely important. Combining this with the hygroscopic properties of polyamide yields vital information about the integrity of the molded nylon.Single and double gated specimens were obtained and saturated under controlled conditions to determine the rate of water absorption into the molecular structure of the nylon. Based on this, controlled groups of single and double gated samples were saturated at 10% increase by weight increments and sealed. Finally the change in maximum tensile strength was measured, documented, and analyzed.
Effects of Liquid Rubber Modification on the Flexibility of Fiber Reinforced Epoxy Composites
Cevdet Kaynak, Aslihan Arikan, Teoman Tincer, May 2002
The purpose of this study was to improve flexibility of short glass fiber reinforced epoxy composites by using a liquid rubber modifier. For this purpose, diglycidyl ether of bisphenol-A (DGEBA) based epoxy resin matrix of the composite specimens were modified with hydroxyl terminated polybutadiene (HTPB) liquid rubber. A silane coupling agent (SCA) was also used to improve the interfacial adhesion between glass fibers and epoxy matrix. In specimen preparations, hardener and HTPB were premixed and left at room temperature for an hour before epoxy addition to allow possible reactions to occur. The flexibility of the specimens was evaluated by 3-point bending tests. It was observed that HTPB modification resulted in formation of relatively round rubber domains in the epoxy matrix increasing the flexibility.
Effects of Low Molar Mass Additives on the Molecular Mobility and Transport Properties of Polysulfone
Suel E. Vidotti, Luiz A. Pessan, May 2002
The aim of this work was to study the effects of the incorporation of low molar mass additives into polysulfone (PSF) to improve its water vapor barrier properties. The additives N-phenyl-2-naphthylamine (PNA) at the concentration of 10, 18 and 30% by weight and 2,6-di-terc-butyl p-cresol (BHT) at the concentration of 5, 10, 15 and 20% by weight were incorporated into PSF. The incorporation of these additives resulted in changes on molecular mobility and transport properties of the glassy matrix associated with the antiplasticization phenomena. The effects observed due to the incorporation of the additives were reduction in glass transition temperature, reduction in the magnitude of the secondary loss transition peak and changes in secondary loss transition peak for higher temperatures. The properties of the systems were determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA). The changes in molecular mobility of PSF were accompanied by reductions in its water vapor permeation. The mixtures PSF-PNA showed a reduction on the water vapor permeation of up to 95% for 30% of additive incorporated and up to 81% for mixtures PSF-BHT with 20% of additive.
Effects of Moisture Conditioning Methods on Mechanical Properties of Injection Molded Nylon 6
Nanying Jia, Howard A. Fraenkel, Val A. Kagan, May 2002
The influence of various standard (ASTM, ISO) and experimental moisture conditioning methods on mechanical performance of injection molded nylon 6 is discussed as a result of an in-depth, comprehensive investigation.The analyzed methods covered a wide range of two basic process parameters for conditioning: temperature (from 23 to 100°C) and relative humidity (from 50% RH to water immersion). The variation of these parameters may result in significantly different moisture absorption rates, equilibrium levels and mechanical properties. The kinetic of mechanical performance and microstructure were evaluated prior to tests and during conditioning in this comprehensive analysis.The results from this investigation may provide comprehensive, up-to-date information and recommendations concerning accelerated nylon conditioning methods for test specimens and various molded parts, pre-selection of nylon based plastic for design, and prediction and optimization of mechanical performance.
The Effects of Multiple Heat Histories on the Mechanical Properties of High-Impact Polystyrene
Jonathan DeSousa, May 2002
The plastic materials that make up consumer items are most often discarded after use. However, thermoplastics can be subjected to several recycle histories before they are disposed of in a landfill. Many studies have shown that mechanical recycling can cause some level of degradation of polymer properties. However, few studies have looked at the effect of repeated recycle histories on the properties of plastics. In this study, the effects of multiple recycle histories on the mechanical properties of high-impact polystyrene were determined in an attempt to show that plastics can be quite recyclable even after a large number of recycle histories. In this study, the high-impact polystyrene was reprocessed a total of thirty (30) times. Melt flow rate, tensile properties, and impact properties were determined for these multiple recycle histories. In most cases, the change in properties was relatively small, even for the large number or recycle histories studied.
Effects of Oil Temperature Difference on Part Weight
Albert O. Lorya, May 2002
This project investigates the effects of oil temperature variations on the repeatability of the parts, based on part weight. Two different material types were used for this study: Polypropylene & ABS. These two materials were selected to represent the two types of plastics: semi-crystalline (PP) and amorphous (ABS).The study compared the weights of the parts at three different oil temperatures, and the parts were matched by cycle. The study reveals that the lower the oil temperature the heavier the parts. Also the lower the oil temperature the less the part weight variation was with one material. The findings are based on data collected from two machines.
The Effects of Power Ultrasonic Wave on In-Situ Polymerization and Formation of PMMA-Clay Nanocomposites
Joung Gul Ryu, Hyung Soo Kim, Jae Wook Lee, May 2002
Several methods have been used to synthesize polymer-clay nanocomposites. In-situ polymerization with clay belongs to a classical way to develop nano-structured materials, while melt intercalation is being recognized as another useful approach due to its versatility and environmentally benign character.In this research, we prepared polymer-clay nanocomposites based on the poly (methyl methacrylate) and organically modified montmorillonite via two-stage sonication process. According to the unique mode of power ultrasonic wave, the sonication during processing led to enhanced breakup of the clay agglomerates and reduction in size of the dispersed phase. Optimum conditions to form stable exfoliated nanocomposites were studied for various sonication times, sonication ratios, addition of initiator and different kinds of clay.It was found that a novel attempt carried out in this study yielded further improvement in the mechanical performance of the nanocomposites compared to those produced by the conventional melt mixing process, as revealed by DMA, XRD and TEM.
Effects of Processing Conditions on the Hollow Structure of Liquid Gas Assisted Injection-Molded Parts
Dong-Hak Kim, Kwansik Oh, May 2002
Gas-assisted injection molding (GAIM) offers many advantages such as design flexibility, dimensional stability, reduction of machine tonnages, and so on[1]. But, for thick parts such as handles, it is observed the surface defects including hesitation mark and gloss difference.Liquid gas-assisted injection molding (LGAIM) is a good alternative of conventional GAIM especially in manufacturing simple and very thick parts. We developed total system for LGAIM and applied to several parts[2-4].In this paper, we present experimental investigation on the effect of various processing parameters associated with LGAIM process. The processing parameters chosen for this study included shot size, liquid injection time, delay time, and injection molding machine conditions such as injection speed, injection pressure, and so on. From this study, we obtained the useful design guide for LGAIM process.
Effects of Processing Parameters on the Preparation of High Density Polyethylene / Layered Silicate Nanocomposites
Minhan Kwak, Minhee Lee, Bong-Keun Lee, May 2002
Effects of polyethylene-g-maleic anhydride, processing parameters and molecular weight of matrix polymer on the nanocomposite preparation are demonstrated in polyethylene / layered silicate system using a Haake batch mixer. XRD and TEM techniques are utilized for evaluating the degree of exfoliation. The d-spacing value of the layered silicate, Cloisite 6A, linearly increases with the amount of PE-MAH and the layered silicate is successfully exfoliated over 25wt% at a certain processing condition. Effects of major processing parameters, such as temperature, mixing time and mixing speed, on the intercalation or exfoliation behavior are also clarified in this study. In addition, some discussion about the shear stress and the diffusion of polymer is presented to figure out the exfoliation behavior based on phenomenological results observed in this experimental work.
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