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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Using Iterative Fluid-Structure Interaction Solution to Simulate Core Deflection Problems in Injection Molding
In injection molding process, the fluid-structure interaction (FSI) issue has been widely discussed, especially for core shift deflection problem recently. During the filling stage, a non-uniform pressure distribution within the cavity leads to common structural deformation defects. At the same time, the deformed structure affects filling behaviors. These dynamic deformations and fluid mechanics result in the difficulties of maintaining numerical simulation accuracy and huge computational memory. In this paper, a new iterative FSI coupling method has been developed. The new method not only provides more accurate melt front and pressure result but also predict precisely core deflection simultaneously. Furthermore, a new solid mesh deformation technique is used to rebuild cavity solid mesh automatically in accordance with continually deformed cavity geometry. Moreover, a real case is applied for both numerical simulation and experimental study to validate the iterative FSI coupling method. The results in this paper demonstrate that the high quality deformed meshes are reliable and help to get a good agreement with experiment.
Effect of Polyurethane Surface Treatment on the Thermal and Mechanical Properties of Glass Fiber Woven Composite
In this paper, the effects of fiber surface treatment on the mechanical and thermal properties of glass woven fabric reinforced thermosetting epoxy resin matrix composites are examined experimentally. Four kinds of deposit (pick-up) ratios of polyurethane dispersion (PUD) treatments on the heat-cleaning glass cloth woven fabric were carried out, including 0wt% (without treatment), 0.76wt%, 1.51wt% and 6.49wt%. It is found that the interfacial adhesion and property were affected by the treatment significantly. The correlation among varied PUD surface treatment pick-up ratio of glass fiber, modified interface, improved mechanical property and related thermal property were discussed and clarified based on tensile test, dynamic mechanical analysis (DMA), scanning electronic microscope (SEM) observation.
Blend of Polypropylene and Polyphenylene Ether
The effect of the blending sequence and the viscosity ratio on the phase morphology and mechanical properties of blends of polypropylene and polyphenylene ether was investigated in present study. It is found that that the Izod impact strength of PPE/PP alloy compounded via two step extrusion method can be improved significantly. A preblending SEBS with PPE can make the compatibilizer SEBS move easily to the PPE/PP interface and the blends had finer dispersion and better properties. Also, the experimental results have showed a clear dependence of the blend phase morphology and properties on the viscosity ratio. The Izod impact strength of PPE/PP blend can be improved by decreaseing the viscosity ratio ?PPE/?PP. In addition, the screw configuration containing an elongational flow field has proved to be more effective in deforming particles than a shear flow field, leading to finer dispersion and better properties.
Preparation and Characterization of Poly(N-Isopropylacrylamide)/Graphene Nanocomposites Hydrogel
Graphene oxide/PNIPA ?GO/PNIPA ?composite were successfully prepared through in-situ polymerization. And then using chemical reducing agent, GO/PNIPA was reduction tographene/PNIPA composite. Resulting hydrogels were characterized by FTIR, scanning electron microscopyto investigate the structural, morphologicalproperties. The swelling ratio and response kinetics on heating or cooling were also investigated to understand the smart properties. The result indicated that graphene/PNIPA hydrogel showed good smart property with a higher swelling ratio and more complicated deswelling behavior.
Effect of Small Perturbations in Colour Formulation on Output Colour of a Plastic Grade Compounded with Two Polycabonate Resins
Historical colour data of a compounded plastic grade manufactured at Sabic IP Cobourg Plant has been analysed through statistical means. Objective was to investigate response of output colour to small adjustments in pigments standard formulation recommended to impart desired colour to a plastic grade. The Plastic grade studied was a blend of two polycarbonate resins, five additives and four colour pigments including one organic – the black pigment, and three inorganic - white, red and yellow pigments. Color mismatch caused by these adjustments is presented in terms of dL*, da* and db*. Analysis of colour deviation caused by such adjustments reveals that output colour values are more sensitive to perturbations in white and yellow pigments amount compared with black and red. Results of optimization carried out to minimize colour deviation, are also presented for the plastic grade.
Experimental Study to Investigate Effect of Process Variables on Output Colour of a Compounded Plastic Grade
For plastic compounders it is imperative to acquire a profound understanding of relationship between extrusion process variables and compounded plastics colour for achieving consistency in output colour. Compounders also need to take educated and precise decisions while incorporating any changes in process variables to minimize deviation of output response from target colour for a compounded plastic. Such a relationship has been investigated using an efficient and economic design of experiments (DOE) for a polycarbonate resin-based compounded plastic. Present study has discussed the results of designed experiments and shed an insight on individual as well as combined influence that process parameters impose on output colour. Three process parameters under study are temperature, feed rate and screw speed. Results of confirmation DOE has also been discussed, which have verified fitness of statistical model used for analysis. The study further suggests a set of optimal process conditions that could be implemented ensuring consistency in compounded plastic colour with minimum deviation from target.
Towards a High-Performance Epoxy Resin Free of Bisphenol A (BPA)
Bisphenol A is a key component of many epoxy resins, but is under pressure especially in food contact applications, necessitating the identification of high performance alternatives. In this work we report on the preparation, properties and performance of one such alternative, the bis(epoxide) of 2,2,4,4-tetramethyl-1,3-cyclobutanediol. This resin has been crosslinked with a typical amine hardener to produce a stiff, hard thermoset with a high Tg. Curing behavior and cured resin properties are improved vs. the bis(epoxide) of cyclohexanedimethanol, a structural isomer of CBDO. Compared to a BPAbased equivalent, resin viscosity and UV cutoff are lower and lap shear adhesion to mild steel is superior, the latter on par with a commercial heavy duty epoxy adhesive. These results indicate promise from this material as a high-performance BPA-free epoxy resin.
Foaming of Cellulose Fiber Reinforced Polylactic Acid Composites: The Effect of Cellulose Fiber Type
This paper investigates the effect of fiber type and fiber content on the foaming behaviors of cellulose fiber reinforced polylactic acid composites. Two types of cellulosic fibers with different sizes were used: micro- and nano-sized fibers. The composites were prepared by a film casting and hot pressing method and then foamed via a batch foaming process with CO2. The morphology and volume expansion ratio of the samples with different cellulose fiber contents were compared. The results suggested that micro-sized fibers had negative effects on the foam morphology and nano-sized fiber positively influenced the foam morphology. It is speculated that the crystals generated around the fibers affected the cell morphology significantly.
Challenges in Qualification of Open Loop Post Consumer Recycle Polystyrene for its use in Engineering Thermoplastics
Polyphenylene Ether (PPE) is an engineering thermoplastic resin usually blended with polystyrene (PS) [crystal polystyrene (CCPS) and or High Impact Polystyrene (HIPS)] to improve properties including the processability. The overall performance of the resulting Noryl™ resin is highly dependent on the quality of the PS. This study presents some of the challenges involved in qualifying open loop PCR PS and key factors that could have affected their performance due to the recycle history and contaminations of the raw material compared to the virgin PS. PCR HIPS properties were simulated by recycling & spiking virgin HIPS with the contaminations.
Effect of Polycarbonate Oligomer on Weld Properties of Injection Molded Polycarbonate and PBT Alloy Material
In this study, the effect of polycarbonate oligomer (PC-O) addition on weld properties of injection molded polycarbonate (PC) and PBT alloy material was investigated. As a result of morphology observation around weld line, the size of PBT domains became smaller with an increase of PC-O and those were quite stretched when those are close to V notch. Charpy impact strength and V notch roughness were also improved when an addition of PC-O was increased. These results suggest that PC-O contributes to both flowability increase and compatibility of PC and PBT.
Effect of Weld Line and Scratch on the Mechanical Property of Injection Molded Polypropylene and Polycabonate Plates
Multi-gate injection is often used to meet the demand of mass production of injection moldings, therefore weld line is inevitable. Weld line can not only affect the appearance quality but also reduce the mechanical property of injection molding productions and many researches focus on the improvement of weld line property. In this research, the effect of weld line and scratch on the mechanical property of PP and PC plates was investigated based on the drop impact test and SEM observation. For PP specimens, maximum load of weld specimens and scratch specimens decreased by 40% and 77% than that of non-weld specimens. The total energy of weld specimens and scratch specimens decreases by 68.9% and 75.0% than that of non-weld specimens. It indicated that there is significant effect of weld line and scratch on the drop impact property. For PC specimens, all the non- weld, weld and scratch specimen were not penetrated and the energy at maximum load is almost same. It reveals that there is no significant effect of weld line and scratch on the impact property of PC specimens.
The Development of a Long Carbon Fiber Thermoplastic for Automobile parts
The aim of this study was to optimize the long carbon fiber thermoplastics process. First of all, to increase interaction between carbon fiber and polypropylene matrix polymers, maleic anhydride grafted polypropylene was used according to different graft ratio. The composites were prepared by long fiber thermoplastic (LFT) system by Honam petrochemical Corp. Tensile, Flexural test and scanning electron microscopy (SEM) were performed to characterize the physical and morphological properties of the prepared composites. The tensile and flexural strength value of Polypropylene (PP)-long carbon fiber thermoplastic (LCFT) with PP-g-MA were higher compared to the values of carbon fiber reinforced PP composites. It was observed from SEM images that the addition of PP-g-MA in process improved the interfacial adhesion between the carbon fibers and PP matrix. Impregnation system was also optimized for improvement of wettability between carbon fiber and matrix polymer. Spreader pins which spread the fiber bundle were introduced in impregnation die and the optimum number of pin was investigated for prevent fiber damage.
Mechanical properties of poly (lactic acid) based biocomposite : Comparison of different reinforcement
The poly (lactic acid) (PLA) based biocomposite reinforced with different natural reinforcement consisting of bamboo fiber, vetiver grass fiber, coconut fiber, silk fiber and bamboo charcoal powder were prepared and the mechanical properties were tested. To enhance the adhesion between reinforcement and PLA matrix, the flexible epoxy resin was selected and used as a novel surface treatment for natural reinforcement. It was found that the stiffness of untreated biocomposites increased significantly. However, the mechanical strengths such as tensile, flexural and Izod impact strength of composites decreased with increasing of reinforcement content. The flexible epoxy surface treatment reduced the stiffness of all composites while it increased considerably the tensile, flexural and impact strength when comparing with the untreated composites. However, it can be seen that the effects of flexible epoxy treated on the mechanical strengths improvement are dependent on the type of reinforcement. There are two interfaces consisting of interface between reinforcement and flexible epoxy resin and interface between flexible epoxy resin and PLA matrix, which resulted in the different fracture mechanism.
Tensile strength prediction of hybrid glass and jute fiber reinforced polypropylene injection molded composite
In this paper, the tensile strength of hybrid polypropylene composites reinforced with glass fiber and jute fiber has been studied. The specimens have been fabricated by injection molding with different jute fiber hybrid content. The tensile strength of hybrid composite was predicted by using a modified rule of hybrid mixture (MRoHM) strength equation based on the orientation direction of reinforcing fiber. The fiber orientation was determined from the fracture surface observation method. Experimentally, the tensile strength of hybrid composite was lower than the monotonic glass fiber/PP composite. Moreover, the further increase of jute fiber content has no influence on the tensile strength of hybrid composites. However, the predicted strength of hybrid composites decreases with increasing of jute fiber content. The reduction of predicted strength is contributed to the effect of reduction of glass fiber length and increment of 90 degree orientation of jute fiber. It was interest to note that the tensile strength of hybrid composites was higher than that predicted by the modified rule of hybrid mixture, showing a positive hybrid effect between glass fiber and jute fiber.
The Effect of Drying on Coating Thickness Variation in Mico Gravure Roll to Roll Coating Process
Coating thickness variation along the transverse direction is a crucial defect in micro gravure roll to roll coating process to manufacture hard coated plastic film. This variation takes place mainly due to the applied tension to substrate and the solvent evaporation during the drying process. In this study, the effect of drying conditions on the coating thickness variation was investigated. It was found that slow drying rate resulted in the lowering of thickness variation. Drying temperature and roll speed (web speed) are main processing parameters to control the drying rate. In addition, the characteristics of coating solution such as solvent, solid content and molecular weight also affected the drying rate in micro gravure roll to roll coating process.
Post Consumer Recycled Based NORYL™ Engineering Thermoplastics Product Portfolio for Electronic and Electrical Applications
The Noryl™ resin compositions discussed in this paper are prepared using polyphenylene ether and post-consumer recycled (PCR) polystyrene (PS). The use of PCR in these environmentally progressive Noryl™ resin products may reduce plastic waste diverted to landfill, thereby lowering carbon footprint and energy conservation when compared to virgin Noryl™ resins. A comparison of properties of Noryl™ resins comprising PCR PS versus virgin Noryl™ resins will be presented in this paper. Life cycle assessment work is in progress and will also be presented during conference.
Synthesis of Sulfur Extended Polymer for use in Asphalt Binder
Sulfur extended Polyvinyl Acetate co-polymers (SEPC) were prepared in a melt blender at 100 rpm for different times and temperatures, and mixed with asphalt in pug-mil to improve its quality for road maintenance applications. The amounts of SEPC in asphalt vary according to the properties of asphalt used. SEPC was mixed with asphalt at 4-6% by weight. The SEPC blended asphalt was mixed with asphalt concrete in Marshall mix at 140°C using different ratios to produce polymer modified asphalt concrete mix (PMACM). The resulted PMACM was studied by means of stability, stability loss, performance grade )PG(, rutting resistance, fatigue resistant and the results showed improvements in the properties. The results are within the acceptable limits and comparable to the results obtained for other commercial polymers such as polybilt. The presence of chemically bonded sulfur will reduce the amount of polymers to be used in asphalt modification and add value to elemental sulfur. The use of SEPC in asphalt is expected to increase the service life of highways and reduction in maintenance cost.
The Potential for Solid Biomass Wastes as Fillers in Polymer Compounds
Two solid waste streams that originated either directly from biomass or from the processing of biomass material have been evaluated for their potential as fillers in thermoplastic compounds. In this initial investigation the two materials were taken directly form the source and compounded with the thermoplastic without any conditioning. Injection molded samples were characterized, mechanically tested and compared to compounds made from a commercial masterbatch. The results indicated that both of the waste materials could be used to make compounds with consistent, and, for some applications, improved properties compared to current commercial compounds.
Influence of Film Former Type and Fiber Length on Processing and Properties of Sisal Fiber Reinforced Polypropylene
The aim of this work was to investigate the influence of the film former type applied on a sisal yarn prior to cutting on the processability of said cut fibers. Furthermore, the effects of the film former on the mechanical properties of the prepared composites are also investigated. We found, that it is possible to use different film formers for producing dosable fiber bundles. Furthermore, the type of film former shows an influence on the processability as well as on the mechanical properties of the composites. Although a reduction can be found in few properties, the use of a film former enables the dosing of fiber lengths on standard equipment, which are not processable if unsized
The Influence of Design and Processing Parameters on the Mixing Performance of a Fluted Mixer
In this paper, the mixing efficiency of two slightly different fluted mixing elements is studied. RGB spectral analysis is used for the quantification of the mixing. The overall mixing appears to be equal after sufficient mixing time. The mixer without the wiping flight, however, creates a stagnation layer of material which rotates between the mixer and the barrel. This layer is characterized by a long residence time. The residence time of the layer is twice as long as for a mixer with the wiping flight. The long residence time is again measured by RGB spectral analysis and also visualized in the video. The results of a 3D FEM simulation shows that the mass flow rate of the stagnation layer represents almost 50% of the total mass flow rate.
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