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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Practical Applications of Polyethylene with Excellent Easy Processability
The melt rheological properties of an ethylene/alpha-olefin copolymer polymerized by a supported metallocene catalyst, which have been developed as the easy processing polyethylene by Sumitomo Chemical, were evaluated and compared with conventional polyethylenes. The melt viscoelastic properties of the copolymer exhibit a shear rate dependence similar to that of high-pressure low density polyethylene that is considered to be caused by the wide molecular weight distribution and long chain branched molecular structure.In the latter part of this presentation, we have focused on the performance of the above copolymer. This copolymer exhibited superior processability in the fabrication of blown film such as low temperature and high output processing, leading to the production of a clean film without any additives and with low odor and taste.
Superhydrophobic Valve for Microfluidics
Capillary valve (CV) is one of the passive valves used to control the fluid flow in microfluidics. Many designs and applications have been based on the capillary valve including the compact-disk microfluidic platform technology. However, the valve loses its function when being used to hold the protein solutions or subject to protein solutions which are applied to treat the surface for non-specific binding. A novel fishbone" micro-valve design based on the concept of superhydrophobicity was developed in this study. The experimental results showed that the valve remains its function even being subject to the protein solutions. It was also tested on the CD microfluidic platform in which the flow control was demonstrated during disk rotation under various conditions."
Mechanical Properties of Natural Hydroxyapatite/PP Composites
Cattle bone-based hydroxyapatite (HA) powders were prepared. Two types of silane coupling agents, i.e. vinyltriethoxysilane (VTES) and 3-methacryloxypropyltrimethoxysilane (MPTS) were used to modify the HA surface. Untreated HA powders and silane-treated HA powders were utilized to produce HA/polypropylene (PP) composites containing a 60% (w/w) of HA content. Effect of types and contents of silane coupling agents on mechanical and morphological properties of HA/PP composites were investigated. The results indicated that treating HA surface with a silane coupling agent enhanced tensile strength and Young’s modulus while reduced impact strength and flexural strength of the composites. Among various HA treating conditions, 2%-MPTS-treated HA provided the highest improvement of tensile strength and stiffness of HA/PP composites.
Using Reflectance Fourier Transform Infrared Spectroscopy and Contact Angle to Quantify Oxidation of Polypropylene
The objective of this investigation was to determine if Reflectance Fourier Transform Infrared Spectroscopy or contact angle measurements could be used to quantify surface oxidation of polypropylene. Contact angle was determined to not be useful as a measure of extent of surface oxidation. By contrast, the area of the carbonyl peak as measured by Reflectance FTIR was not only found to correlate well with exposure conditions, but the results were considerably easier to interpret. The peak area was found to correlate well with exposure time, UV exposure level, and the interaction between temperature and exposure time. These results suggest that Reflectance FTIR should be useful for quantitatively characterizing the level of oxidation of a polyolefin surface.
Effect of Processing Aids and Flame Retardant Synergists of HFFR Thermoplastics on Extrusion Processability and Flame Retardant Performances
Inorganic flame retardants, such as aluminum trihydrate(ATH) and magnesium dihydrate(MDH), are most widely used fillers in halogen-free flame retardant(HFFR) polyolefin materials, especially for wire and cable. These inorganic fillers are used in great amount, and influence the mechanical properties as well as flame retardancy significantly. Also, they commonly deteriorates the processability and raise a problem such as die lip buildup. Therefore, it is very important to reduce the inorganic filler contents in HFFR by the addition of flame retardant synergist. The effects of flame retardant compositions on the mechanical properties, flame retardancy and processing performance, especially die lip buildup characteristic, were investigated here.
Effect of Compounding Procedure on Mechanical Properties of PLA/PCL Blends
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.
9 Molds in 10 Weeks
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.
Prediction of Non Linear Visco-Elastic Deformations
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.
Woven Glass Fabric Composites via In-Situ Polymerized Cyclic Butylene Terephthalate Oligomers
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.
Numerical Simulation and Experimental Study on Metal Injection Molding
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.
Structure Evolution in ?- and ?-Polypropylenes Under UV Irradiation
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.
FEM Research on Cooling for Large and Complicated Blow Molded Part
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.
Experiments in Ultrasonic Micro-Embossing of PMMA
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.
Marketing a Plastics Engineering Technology Program
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.
Creep Prediction for Polymers: Implementation and Its Application on a Talc Filled Polypropylene
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 Cornstarch-Reinforced Biodegradable Biocomposite
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.
The Effect of Formulation and Process on Thermoformable TPO Gloss
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.
Compatibilization of ABS/PA6 Blends Using Olefin Based Polymers
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 of Semi-Crystalline Plastics
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.
Vapor Transport Properties of Sulfonated Block Copolymers
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.
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