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

DIELECTRIC BEHAVIOR OF POLY(VINYLIDENE FLUORIDE)/GRAPHENE COMPOSITES WITH LOW PERCOLATION THRESHOLD

Ping Fan, Lei Wang, Feng Chen, Jingtao Yang, Mingqiang Zhong, May 2012

Poly(vinylidene ?uoride) (PVDF)/graphene composite was successfully fabricated by a solution-cast and hot- pressing method. The composite material with graphene as conductive ?ller exhibited a very low percolation threshold (0.0018 volume fraction), but the dielectric constant was enhanced signi?cantly. The largest dielectric constant of 7940 was observed for the PVDF/graphene composite with 0.0177 graphene volume fraction at 100 Hz. Large enhancements of the ac conductivity and loss tangent were also observed for the composites with graphene content near the percolation threshold. The percolation theory was used to explain the dielectric behavior of the composite.

THE EFFECT OF FEEDING PROFILE IN THE DISTRIBUTION OF CHAINS COMPOSITION AND MECHANICAL PERFORMANCE OF STYRENE/BUTYL ACRYLATE EMULSION COPOLYMERS

Alvaro Arnez, Luis González, Francisco Aranda, Carlos Jasso, May 2012

A semicontinuous process was used to prepare copolymers varying the feed composition profile, to vary in a gradual manner the composition of the copolymer chains being formed through an emulsion reaction, for the (50/50, w/w) styrene/butyl acrylate system. With the cumulative composition of the copolymers (1H-NMR), the weight distribution of chains composition (WCD) was estimated, constructing a histogram that is used to elucidate the mechanical behavior (DMA, stress-strain and, impact strength) of the synthesized copolymers.

EVALUATION OF DEGRADATION OF BACK-SHEET FOR PHOTOVOLTAIC PANELS

Akinori Iguchi, Hideo Hirabayashi, View Paper Kazushi Yamada, Hiroyuki Nishimura, Yasuhiro Uchiyama, Jyunpei Kojima, May 2012

To expand use of photovoltaic generation, there is a real need for reducing cost of generating by photovoltaic panels. One of cost-cutting of power generation is to prolong its service life. It is very important to prevent moisture from penetrating the back-sheet for insuring the long-life operation of photovoltaic panels. In this study, the correlation was evaluated between mechanical property and partial discharge of degraded polyethylene terephthalate film for the back-sheet.

POLYMER COMPOSITES WITH HOLLOW GLASS MICROSPHERES: PROCESSING, PROPERTIES AND APPLICATIONS

Baris Yalcin, Steve E. Amos, Troy K. Ista, DS Park, Marcel Doering, Stefan Friedrich, Takijurou Yamabe, Sedat Gunes, May 2012

Reducing the weight of thermoplastics and rubber parts has been a paramount objective in various industries such as transportation, aerospace, hand-held electronics and sports and leisure. 3M ™ Glass Bubbles (hollow glass microspheres) are light weight micro additives specially engineered to withstand temperature, stress, and deformation gradients in a wide range of polymer processes ranging from liquid phase polymer processing to high viscosity melt compounding and high pressure injection molding. We will present factors influencing glass bubble survival and discuss processing methodologies to achieve the highest level of bubble survival for a given polymer grade, specifically during twin screw extrusion compounding and injection molding. We will then analyze application examples and demonstrate how the plastics industry and associated OEMs can exploit the light weight advantages of these novel additives while improving the processing and end-product properties without resorting to costly equipment modifications.

VALVE GATE OPTIMIZATION FOR INJECTION MOLDING OF AN AUTOMOTIVE INSTRUMENT PANEL

Sung-Bin Cho, Chang-Hyun Park, Dong-Hoon Choi, Byung-Gi Pyo, Byung-Ohk Rhe, May 2012

Injection pressure, an important factor in injection molding process, should be minimized to enhance injection molding quality. In this study, we decided the locations and open timings of valve gates to minimize the maximum injection pressure. To solve this problem, we integrated MAPS-3D (Mold Analysis and Plastic Solution-3Dimension), a commercial injection molding analysis CAE tool, using the file parsing method of PIAnO (Process Integration, Automation and Optimization) as a commercial process integration and design optimization tool. In order to reduce the time for obtaining the optimal design solution, we performed an approximate optimization using a meta-model that replaced expensive computer simulations. To generate the meta-model, computer simulations were performed at the design points selected using the optimal Latin hypercube design as an experimental design. Then, we used micro genetic algorithm available in PIAnO to obtain the optimal design solution. Using the proposed design approach, the maximum injection pressure was reduced by 35.1% compare to the initial one, which clearly showed the validity of the proposed design approach

STUDY OF PRODUCING MICROCELLULAR INJECTION MOLDED PARTS WITH IMPROVED SURFACE QUALITY

Jungjoo Lee, Lih-Sheng Turng, Eugene Dougherty, Patrick Gorton, May 2012

This paper describes a novel approach to achieve swirl-free foamed plastic parts using the microcellular injection molding process. With a better understanding of the cell nucleating behavior, which is governed by the degree of supersaturation, one can delay the onset of cell nucleation during mold filling, thereby allowing a solid skin layer to form on the part surface prior to foaming. The theoretical background of this approach as well as the experimental results are presented.

DEVELOPMENT AND CHARACTERIZATION OF LOW DENSITY POLYETHYLENE/CELLULOSE MICROFIBRIL COMPOSITES

Sherly Paul, Harsha B, Vidya V, Asworthy R, May 2012

Banana microfibrils were prepared from banana fibre obtained from the pseudo stem of the banana plant by steam explosion process. Alkali and acid treatment coupled with high pressure defibrillation was found to be effective in the depolymerization and defibrillation of the fibre to produce the microfibrils. The different stages of steam explosion process were studied by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Atomic Force microscopy studies (AFM) revealed that the surface of the microfibrils were rough. The prepared micro fibrils were subjected to chemical treatments with potassium permanganate (KMnO4) and benzoyl chloride. Low density polyethylene (LDPE)/microfibril composites were prepared by injection molding. The dielectric and mechanical properties of composites and chemically treated microfibril composites were investigated. Dielectric constant of LDPE/microfibril composite was found to be greater that of neat LDPE. Chemical treatments reduced the dielectric constant of the composite. The mechanical properties were found to be increasing upto 20% microfibril loading. Chemical treatments further enhanced the mechanical properties of the composite.

RAPID HEATING AND COOLING SIMULATION FOR THE INJECTION MOLDING PROCESS

Clinton Kietzmann, Lu Chen, Harold Lin Feng, Franco Costa, May 2012

In recent years, injection molding technologies have been developed which use variable mold heating and cooling to improve surface finish and general part quality without significantly increasing cycle time. Simulation of these processes requires a transient time dependent mold thermal analysis. This paper presents the further development of a 3D finite element based transient mold cooling simulation capability to include the rapid heating and cooling cycling of the mold. The various rapid heating and cooling stages are explained as well their effect on the part during filling.

INVESTIGATION OF DYNAMIC MECHANICAL PROPERTIES OF METAL-POLYMER FILAMENT FOR FUSED DEPOSITION M0DELLING

Syed Mahroosh Hussain, Syed H. Masood, Mostafa Nikzad, May 2012

POM or polyoxymethylene is an engineering resin used primarily for injection molded parts that replace metal. POM’s usefulness is derived from the combination of strength, stiffness, toughness, creep resistance, and lubricity. POM homopolymer and copolymer compete in this market space. Homopolymer grades have some mechanical advantages while copolymer grades have better thermal and chemical stability. In 2010 Ticona introduced a new high strength, high viscosity POM copolymer with the mechanical properties of a typical homopolymer, while maintaining copolymer stability. This paper introduces an improved flow, high strength POM copolymer, its property profile, salient features and potential applications.

DURABILITY, RELIABILITY AND SAFETY STUDY OF POLYMERS USED IN PHOTOVOLTAIC MODULES

Hsinjin Yang, J. Thomas Chapin, Ethan Wang, Jerry Yen, Carl Wang, Ivan Chou, May 2012

The primary objective of this study was to investigate the effect of damp heat (DH) and ultraviolet light (UV) exposures on the properties and performance of polymeric materials in photovoltaic (PV) modules. The study covers the evaluation of ethylene vinyl acetate (EVA) encapsulant, TPE (PVF/PET/EV A) substrate, and laminate coupons and modules as a function of exposure time to DH (85°C, 85% RH), and UV (100W/m2, ~2 suns UV irradiance). The results showed that DH exposure had a greater aging effect than UV, and the materials exhibited a greater degree of degradation with increasing exposure time.

A CONTRIBUTION FOR QUALITATIVELY MODELING OF FRICTION AND WEAR BEHAVIOR OF THERMOPLASTICS

Dietmar Drummer, Michael O. Kobes, Daniel Merken, May 2012

Tribological parameters are results of a complex system; therefore their behavior can not easily be predicted. This paper suggests a model for characterizing tribological behavior by the distinct contribution of basic friction, and wear modes. These modes and the transition from one to another are influenced by material, geometric, and other system properties. The presented model is based on broadly accepted, mostly two-dimensional, correlations and supported with own pin-on disc friction and wear experiments.

EFFECT OF PROCESS VARIABLES ON THE PROPERTIES OF SUPERCRITICAL CO2 FOAMED PS/GRAPHITE NANOCOMPOSITE FOAM

Shu-Kai Yeh, Chien-Hsiung Huang, Kuo-Chung Cheng, Wen-Jeng Guo , Tsu-Huang Chuang, May 2012

Polystyrene / nano-graphite nanocomposite foams were made by melt compounding and in-situ polymerization. The foam was made by batch foaming. The cell morphology was improved with the advanced dispersion of the nanoparticles. In-situ polymerization provided better dispersion and the resulting nanocomposite foam had fine cell size. Adding nanoparticles as a nucleating agent can make foams at a lower foaming pressure. This discovery creates a new route to produce microcellular foams at a low foaming pressure.

DESIGN OF INDUCTION HEATING MODULE FOR UNIFORM CAVITY SURFACE HEATING

Yu-Ting Sung, Yu-Ning Lin, Sheng-Jye Hwang, Huei-Huang Lee, Durn-Yuan Huang, May 2012

Electromagnetic induction heating has many advantages such as fast heating, low energy consumption and environmental pollution reduction. Using induction heating for rapid tool heating is more economic and efficient than any of the tool heating technique. Previous studies using electromagnetic induction heating for rapid tool heating indicate that the temperature uniformity on cavity surface is not easy to be achieved no matter with surface or insert type induction heating. In this paper, a series of experiments were conducted to study the effectiveness of temperature uniformity on mold cavity surface for different induction heating coil. The parallel type coil and magnetic flux concentrators were adopted to form the induction heating device. According to the results of heating experiments, the surface temperature of 10 mm thickness hot work die steel (JIS SKD61) could rise from 50°C to 150°C in 15 seconds and the temperature uniformity of the heated zone reached 94%~95%.

A SIMULATION OF INJECTION STRETCH-BLOW MOLDING PROCESS BY USING A VISCO-PLASTIC MODEL

Heung-kyu Kim, Baeg-Soon Cha, Hyung-Pil Park, Dong Han Kim, Min Jae Song, May 2012

A finite element simulation of ISBM (Injection Stretch-Blow Molding) Process was conducted based on visco-plastic material model assumption for PET. ISBM process for obtaining a circular PET bottle was designed in terms of stretch displacement and blow pressure. And parametric study was conducted to examine the effect of visco-plastic properties on the final properties of PET bottle. Based on the finite element simulation results, the predictability and limitations of visco-plastic material model was discussed.

FABRRICATION OF HIGHLY TUBULAR POROUS CHITOSAN/POLY (DL LACTIC-CO-GLYCOLIC ACID) (PLGA) NANOCOMPOSITE STRUCTURES INTENDED FOR TISSUE ENGINEERING SCAFFOLD APPLICATIONS

Zhixiang Cui, HaiBin Zhao, YiYen Peng, XiaoFeng Wang, Jian Han, Lih-Sheng Turng, Changyu Shen, May 2012

In this study, highly tubular porous chitosan/poly (DL lactic-co-glycolic acid) (PLGA) nanocomposite structures were produced via electrospinning and unidirectional freeze drying techniques. The 3D porous structure of chitosan/PLGA was characterized by scanning electron microscopy (SEM). The properties of the chitosan/PLGA nanocomposite, including porosity, water absorption, and mechanical properties, were investigated. The results showed that a highly tubular porous structure with nano-topography was formed and the compressive modulus increased greatly due to the addition of PLGA nanofibers.

ACCELERATED CHARACTERIZATION OF THE RESISTANCE AGAINST CRACK INITIATION AND SLOW CRACK GROWTH OF POLYETHYLENE FOR GEOMEMBRANE APPLICATION UNDER THE INFLUENCE OF MEDIA

Anita Redhead, Andreas Frank, Gerald Pinter, May 2012

Two different HDPE-grades were investigated concerning media-resistance. Cyclic tests with CRB-specimen were conducted under three different configurations, tests on exposed and unexposed specimens and tests in a special glass cell with a liquid environment. Additionally conventional immersion-tests with subsequent tensile-tests, OIT-measurement and Infraredspectroscopy were done. A swelling effect of both media and a skin-deep chemical aging was evidenced. Cyclic CRB tests showed comparable results with more pronounced effects for the results of the media cell.

MELT EXTRUSION OF A PHARMACEUTICAL COMPOUND CONTAINING A POORLY SOLUBLE THERMOLABILE DRUG

Adrian Kelly, Chaitrali Kulkarni, Tim Gough, Ravindra Dhumal, Anant Paradkar, May 2012

Solid dispersions of the poorly soluble, thermolabile drug Artemisinin in a polymer matrix have been developed using twin screw extrusion. Artemisinin is a particularly challenging drug to use in melt extrusion due to its inherently temperature and process sensitive nature. A co-polymer developed for pharmaceutical extrusion was used as the matrix material and experiments were performed to assess the suitability of this drug-polymer combination at a range of drug loadings and process conditions. The drug was found to act as a plasticizer during extrusion and to be miscible in the polymer matrix. Artemisinin was found to be susceptible to degradation at extended residence times at process temperature. A half length extruder screw configuration was used to minimize degradation of the drug and this yielded optimum drug release rates.

BIO-BASED POLYAMIDES WITH INNOVATIVE FIBRES FOR ENGINEERING PARTS MATERIALS – PROCESS – CHARACTERIZATION - APPLICATIONS

M. Feldmann, AA Mamun, A.K. Bledzki, H. - P. Heim, May 2012

Bio-based polyamides, such as PA 6.10/ Nylon 6.10 and PA 10.10, were compounded with different cellulosic fibers for injection molding applications. PA 6.10 is partly bio-based (>60%) and possessing properties very similar to those of common PA 6. The melting point of PA 6.10 is 220°C and therefore compounding with thermally sensitive cellulose fibres is a challenge. A compounding process for engineering polymers, like polyamide with cellulose fibres, was developed and optimized. It is gentle to the fibers, even at temperatures above 200°C. Furthermore, the molding process parameters were also optimized. Different mechanical properties were studied. The high impact behavior and lightweight potentiality were analyzed for bio-composites with cellulosic fibres.

PREDICTION OF ELASTIC MODULUS OF HYBRID INJECTION MOLDED COMPOSITE

Putinun Uawongsuwan, Yuqiu Yang, Tomoko Ota, Manabu Nomura, Toshikazu Umemura, Hiroyuki Inoya, Hiroyuki Hamada, May 2012

The main drawback of natural fiber reinforced composite is their low mechanical properties. In order to overcome this problem, the hybridization of natural fiber with synthetic fiber was proposed. This work is focused on evaluation of mechanical properties in particular elastic modulus of short glass-jute fiber hybrid polypropylene composite. The specimens have been fabricated by injection molding with different jute/glass fiber hybrid ratios. Experimentally, the tensile modulus of hybrid composite increased with increasing jute fiber content. Theoretically, the elastic modulus is predicted by using classical lamination theory (CLT). The fiber orientation was determined from the fracture surface observation method. Prediction by CLT showed close agreement with experimental values with a maximum deviation of about 5.6%.

FALLING DART IMPACT BEHAVIOUR OF POLYCARBONATE AND MICROCELLULAR POLYCARBONATE FOAMS

Andrzej K. Bledzki, Hans-Peter Heim, Martin Rohleder, Sebastian Schaub, May 2012

Foamed polymers are well know for a high energy absorption and mechanical and acoustic damping. Foams in these applications were usually produced by extrusion or reaction foaming. Based on this fact, injection moulded foams are rarely analysed with regard to their damping behavior at dynamic load. This investigation deals with the analysis of injection moulded polycarbonate foams, produced with physical blowing agent. The materials were characterized with an falling dart impact test setup. An analysis of the dependence of temperature, the influence of the applied load and the molecular weight of the polycarbonate was carried out.