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.
Umaru Semo Ishiaku, Hiroyuki Hamada, Division of Advanced Fibro-science, Kyoto Institute of Technology, Gosyokaido-cho, Matsugasaki, Sakyo-ku, JAPAN Side feeding technique was applied to Poly lactic acid (PLA)/Polycaprolactone (PCL) blend containing peroxide. Feeding procedures, such as blanket feed in which all the materials are fed into main hopper at once and split feeding using the side feeder, were attempted. The results indicate that tensile properties are not dependent on feeding procedure, but the impact strength was superior in the case of the split feeding samples. It is noteworthy that the impact strength of the split feeding sample was considerably affected as it was four times better. The size of the dispersed phase depends on the feeding procedure as the peroxide is more reactive when split fed.
As part of their major, Plastics Engineering Technology (PET) and Industrial Technology (IT) students at Western Washington University (WWU) are required to take a course in tooling design for plastics processes. The tools and technologies available to WWU Engineering Technology students allow for the complete design, construction, and implementation of an injection mold tool in the 10 weeks of the course.Students gained experience in the areas of tool design, program management, and problem solving while constructing their mold. Certain unique features on the molds will be used to illustrate the diverse solutions devised by the students. Every team used CAD/CAM software, CNC and manual mills, and a 40 ton injection molding machine available on campus to complete the projects. The mold design and construction exposed students to every phase of the mold design and manufacturing process.
Long term deformations of complex products can be predicted using Finite Element Method (FEM) calculations. To demonstrate the possibilities of computer simulation of the long term behavior in the design stage an air inlet has been taken as an example.A problem in this prediction was to obtain accurately measure relevant creep and recovery data.Before carrying out FEM calculations the non-linear material behavior must be modeled in an appropriate way for the FEM calculations.The long term deformation can be predicting using commercial FEM programs like MSC-MARC. User subroutines are required to carry out analyses accounting for the non-linear visco-elastic behavior.Experimental verification is required to obtain confidence in the material modeling and the non-linear viscoelastic FEM calculations.
The possibility of fabricating continuous fiber thermoplastic composites has been limited by the inherent difficulties associated with the thermoplastic matrices, such as high processing temperatures and high melt viscosities. This problem, to a certain extent, has been solved via the development of cyclic oligomers which is a low viscosity prepolymers that can be injected into the mold and polymerized in-situ. One of the main types of cyclic oligomers is cyclic butylene terephthalate (CBT). Woven glass fabric (WGF) reinforced in-situ poly(butylene terephthalate) (ISP-PBT) composites were fabricated by compression molding. Tensile, three-point flexural and short beam shear tests were carried out to investigate the effect of WGF on the mechanical properties of the resulting PBT composites. Microstructural features have been investigated by differential scanning calorimetry (DSC) and scanning electron microscope (SEM). The incorporation of 50 vol.% WGF into ISP-PBT resulted in significant enhancement of both stiffness and strength. Fractographic analysis not only revealed good interfacial bonding between ISP-PBT matrix and WGF but also uniform fiber dispersion in the composite.
Metal Injection Molding (MIM) is a process to manufacture metal parts, combining powder metallurgy with plastic injection molding. This paper deals with experimental and simulation study on MIM process. 3D numerical simulation was performed by using commercial CAE software with considered material database. To understand actual flow behaviors in MIM process, MIM was also performed at various molding conditions, and change of internal cavity pressure and the appearance of MIM products were evaluated. The simulation results were in agreement with the experimental values when the solidification effects on these material parameters were taken into account in this simulation. Especially, solidification temperature is very important parameter for estimation of flow behavior in MIM process.
Commercially available isotactic polypropylene (PP) was modified by a specific ?-nucleating agent based on N,N´-dicyclohexylnaphthalene-2,6-dicarboxamide. From both neat (?-iPP) and nucleated (?-iPP) polypropylenes compression-moulded plates were prepared using various processing conditions, and then exposed to UV-irradiation. Molecular degradation and the evolution of supermolecular structure were determined using infrared and UV spectroscopy, wide-angle X-ray scattering and differential scanning calorimetry. Different impact of UV irradiation on both ?-iPP and ?-iPP is presented. Furthermore, the effect of processing conditions on photodegradability is proved.
An overall theoretical model for the cooling and solidification stage in the extrusion blow molding of large and complicated industrial part was presented. The thermal analysis was firstly carried out for the cooling stage, using the finite element (FE) analysis software ANSYS. For the sake of the convenience for FE modeling, the Parameter Design Language in the ANSYS software was used to create external files accessed by ANSYS GUI directly. To obtain the residual stress distribution for evaluating the deformation and warpage of the part, structural analysis under thermal loads was also performed. The temperature, residual stress, and warpage distributions of the part were predicted and analyzed.
MEMS and micro-fluidic technology are two of the fastest growing areas of micro and nanotechnology today. The rapid fabrication of these devices is crucial to their continued growth and use. Ultrasonic embossing was investigated as a possible means of achieving rapid production of micro features on plastic substrates. Several parameters of ultrasonic embossing were studied in terms of their effect on micro-feature replication. The maximum time observed for full replication was less than 20 seconds. This is greatly reduced from the 1 to 10 minute cycle time needed for conventional hot embossing and micro-injection molding processes. The most critical drawback to ultrasonic embossing that was encountered in this study was the occurrence of sticking to the tool during de-embossing. The de-embossing force was found to be as high as 44 N. The employment of an ultrasonic afterburst was investigated as a way to eliminate the de-embossing sticking phenomenon.
Following a few years of declining enrollment in the Plastics Engineering Technology (PLET) Program at Penn State Erie, the Behrend College, the faculty tried several new marketing methods to sell the program to prospective students, their parents, and the industry for whom they provide skilled employees.At Antec 2005 in Boston, MA the leadership of the Plastic Educators Special Interest Group requested that each school with a Plastics Engineering or Plastics Engineering Technology program submit a paper on how their school is dealing with the problems of reduced enrollment. It is hoped that by sharing ideas for improving enrollment numbers that all schools will benefit.
A creep predictive model in the literature based on strain energy equivalence theory has been implemented and tested. The model only utilizes stress-strain experimental data at two strain rates, and can predict the creep behavior of polymers for up to many years and its failure at any creep load. In addition, the model can extrapolate a given reference stress-strain curve to any strain rate. The implemented predictive model is applied to a 40% talc filled polypropylene (TFPP). Two stress-strain experiments were performed at strain rates of 0.01/min and 0.0001/min respectively. The creep behavior of the TFPP at creep stresses of 10 MPa, 15 MPa, and 20 MPa is predicted based on the two stress-strain tests. The prediction shows fairly good agreement with experimental data.
Thermal analysis and nano-mechanical properties of natural fiber or corn starch-reinforced biodegradable composite were conducted by using a differential scanning calorimeter (DSC) and nano-indenter, respectively. Thermal flow properties of composites were also investigated by using capillary rheometer. The effect of coupling agent and filler on isothermal and non-isothermal crystallization was investigated by Avrami equation and its modified equations. Analysis of kinetic data according to nucleation theories was also performed. Nano-mechanical properties of the reinforcing materials used in this study were also investigated by continuous nanoindentation technique.
Automotive part surface finish can be challenging to converters. Interior parts, particularly the instrument panel, require a surface with very low gloss. For thermoforming operations, these requirements can be especially daunting. When using male thermoforming techniques, the converter does not have the benefit of a molding surface to provide a finish. Thus, the inherent property of the sheet stock must provide the necessary finished part gloss.This study investigated the use of blend compositions of ethylene/a-olefin copolymer elastomers having long chain branches with conventional polypropylene and polypropylene containing long chain branches. The results indicated that low sheeting gloss could be obtained by judicious selection of blend components having optimum branching levels.
This study focuses on the morphologies, mechanical and thermal properties of poly(acrylonitrile-co-styrene-graft- butadiene)/polyamide-6 (ABS/PA6) blends compatibilized with methyl acrylate and glycidyl methacrylate grafted polyethylene (E-MA-GMA) and n-butyl acrylate and maleic anhydride grafted, carbon monoxide modified polyethylene (E-nBA-MAH). The ABS/PA6 ratio (100:0, 80:20, 50:50, 20:80 and 0:100) and compatibilizer content (0, 5 and 10 %) are examined as the experimental variables. Compatibilization improves impact strength of the blends. Super-tough blends were obtained at definite compositions (ABS/PA6/E-nBA-MAH: 50/50/5, ABS/PA6/E-MA-GMA: 50/50/5). Dispersed domain size became remarkably smaller for compatibilized blends compared to incompatibilized ones. It was concluded that olefin based copolymers are potential compatibilizers for ABS/PA6 blends.
Laser transmission welding is an innovative process, which is very suitable for the joining of complex injection moulded parts. When the production demands a high quality of the weld line it is absolutely necessary to consider all the influences of the welding process. While welding semi-crystalline thermoplastics the morphology of the transparent joining partner has to be taken into consideration, because the laser beam characteristics and the amount of energy of the welding process depend extensively on the crystallisation characteristics.Many injection moulding process parameters (e.g. the melt and mould temperatures) affect the cooling conditions of the part, and thereby influence the crystalline structure. Therefore the injection moulding process should be integrated into quality assurance systems for laser transmission welding. In this paper the results of intensive experiments for PBT are documented.
Polystyrene-polyisobutylene -polystyrene (SIBS) and Polystyrene-polyethylene-butylene -polystyrene (SEBS) block copolymers are materials that are known to have excellent barrier properties to hazardous vapors and liquids. However, when these block copolymers are sulfonated, water and small polar molecules are allowed to be transported through the polymer film. In some instances, this could be beneficial and allow the film to be used as a separation membrane.In this paper, the vapor transport properties of these materials are presented and discussed herein, as they relate to the polymer chemistry and chemical modification of the tri-block copolymer.Results suggest that water permeation is not affected by the structure of the mid-block, however the transport of small organic molecules are affected. It was also found that permeation of polar molecules increases with increasing sulfonation levels within the polymer. The elastomeric character of the tri-block copolymer, coupled with its selectively–permeable characteristics, gives rise to a polymeric membrane with potential for use as breathable membranes.
The Plastics industry in Mexico is a very vibrant one with total consumption of plastics in 2004 exceeding 4.5 million tons – ranking it 12th in the world. With abundance of hydrocarbon feed-stocks, reasonable wages and proximity to huge market to the North and the South, plastics sector is very attractive and essential to the socio-economic development of Mexico. However, the unique industry infrastructure and other factors have contributed to importation accounting for over 50% of domestic consumption of plastics. This paper will discuss the current situation with respect to domestic production and consumption of plastics, design and fabrication of molds & dies as well as processing machinery, identifying many opportunities as well as critical challenges for the plastics industry in Mexico.
Ternary nanocomposites composed of polyamide- 6 (PA6) , three types of organoclays and an ethylene/butyl acrylate/maleic anhydride (E-BA-MAH) terpolymer acting as impact modifier for polyamide were melt blended in a twin screw extruder in order to investigate the effects of component concentrations on the final properties. The morphology, melt flow characteristics, thermal behavior and tensile properties of the produced composites were investigated. XRD patterns showed that the interlayer spacing of the organoclays, Cloisite® 25A and Cloisite® 30B increased in PA6-montmorillonite nanocomposites without the impact modifier, as well as in ternary systems. In the presence of elastomer, the MFI of unfilled PA6- impact modifier blend and the MFI of ternary nanocomposites decreased owing to the high viscosity of the elastomer. The crystallinity of the materials decreased in the presence of elastomer and organoclay. Tensile properties of the ternary systems resembled those of binary PA6/elastomer blends. It was concluded that the effect of elastomer was more dominant than the effect of organoclay.
Because of the ban of CFC as an ozone-depleting substance and the undergoing phase-out of HCFC, the foam industry is currently looking at inert gases and HFCs as potential alternative blowing agents. However, contrarily to CFCs and HCFCs that were easily dissolved in the thermoplastic resins and could be readily expandable under relatively mild conditions with a minimum of processing difficulty, these alternative fluids unfortunately lack in solubility and are thus difficult to process. For instance extrusion foaming of polystyrene using HFC-134a is problematic above a concentration of 7wt%. Surprisingly, the pressure associated with this concentration threshold is approximately equal to the critical pressure of the HFC-134a, which may suggest that large clusters of HFC originating from its supercritical state would be responsible for the heterogeneities observed in the cell structure. This issue may be not only limited to HFC-134a as many other alternative gases (carbon dioxide, HFCs, hydrocarbons) may reach the supercritical state under the required processing conditions. Since use of mixtures of physical foaming agents in thermoplastic foam extrusion has been an industrial practice for a long time, the easiest way to circumvent this problem is to add a coagent, with the result of shifting away the critical point (pressure and temperature).
An unintended consequence of the growing consumption of plastics is the increase in amount of plastics products discarded daily by consumers worldwide contributing to growing share of plastics in municipal waste streams. With the product life cycle of most products getting shorter each day, product designers have a responsibility to minimize the negative impacts of their designs on the environment. This paper describes best practices for incorporating environmental impact considerations during various stages of plastics product development, and provides specific guidelines to assist designers for eco-design of plastics products.
Abbreviated terms are routinely employed in the plastics industry in generic marking of molding products to assist in identification of the plastics for separation in recycling besides in trade and technical literatures. Existing ISO, ASTM and other standards provide clear guidelines for abbreviated terms for polymer families. In practice, however, a wide range of inconsistent abbreviated terms are quite common in the industry. This has significant implications for the general consumers as well as those involved with plastics recycling. The challenge is to arrive at uniform globally acceptable single set of abbreviated terms in order to addressing this issue.
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Brown, H. L. and Jones, D. H. 2016, May.
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ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
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