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
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.
INVESTIGATION OF PROCESSING AND RHEOLOGICAL PARAMETERS EFFECT ON FILM BLOWING PROCESS STABILITY BY USING VARIATIONAL PRINCIPLES
Martin Zatloukal, Roman Kolarik, May 2012
In this study, a numerical stability analysis of the film blowing process is performed considering non- isothermal processing conditions, non-Newtonian behavior of the polymer and physically limiting criteria (maximum tensile and/or hoop stress) in order to investigate the complex relationship between processing conditions (internal bubble pressure, heat transfer coefficient, mass flow rate, cooling air temperature, melt/die temperature), material parameters (extensional viscosity, rupture stress, Newtonian viscosity, flow activation energy, power law index) and film blowing stability.
STRENGTHENING THE MESSAGE OF SUSTAINABLE PLASTICS PACKAGING
Mike Tolinski, May 2012
Recyclable, recycled-content, or bio-based plastics packaging will require more than just the right technologies and materials for sustained growth. Sustainable packaging acceptance and use will also require increasing the number of informed, enthusiastic retailers and packaging consumers interested in being “greener.” In short, their positive attitudes must be turned into buying and recycling behaviors. This paper focuses on one way in which packaging producers are drawing consumers’ attention to the recycled-content, recyclability, or bio-basis of new plastic packaging. Simple messages on the packaging itself not only can clarify green claims about the packaging, but can also serve as calls for consumer action. This paper considers the effectiveness of various messages and, referencing the U.S. Federal “Green Guides,” considers the ways in which a clear, honest sustainability claim can be communicated to both informed and skeptical audiences.
SERVO-DRIVEN ULTRASONIC WELDING OF BIOCOMPOSITES
Sean T. Flowers, May 2012
Due to increasing desire to incorporate biocomposites into numerous applications, there is high demand for welding methods that produce consistent, high-strength joints. A servo-driven ultrasonic welding system for joining bio-derived polylactic acid (PLA) and polypropylene (PP) biocomposites was evaluated. The primary objective was to evaluate material weldability and not, at this stage, to necessarily optimize the weld process. An injection-moldable grade of PLA plastic was included in this study due to its high popularity. Wheat straw-filled PP biocomposite-welded samples were compared to non-filled PP and glass-filled PP samples.
ANALYSIS OF TERNARY NON-COVALENT FILLER/MATRIX/ UV STABILIZER INTERACTIONS IN CARBON NANOFIBER/ PMMA COMPOSITES VIA TIME-RESOLVED FLUORESCENCE EMISSION SPECTROSCOPY
I. Sedat Gunes, Cesar Perez-Bolivar, Guillermo Jimenez, Fengyu Li, Pavel Anzenbacher, Sadhan Jana, May 2012
Non-covalent interactions between the carbon nanofibers (CNFs), oxidized carbon nanofibers (ox-CNFs), poly(methyl methacrylate) (PMMA) chains, and benzotriazole-containing UV stabilizers were analyzed using time resolved fluorescence emission spectroscopy and fluorescence lifetime imaging microscopy. The results indicated that PMMA chains form hydrogen bonds both with ox-CNF fibers and the UV stabilizer molecules. It was also determined that UV stabilizers strongly interact with CNF particles via ?-? interactions. The extent of ?-? and hydrogen bonding interactions was determined to be lower between ox-CNF particles and UV stabilizers due to less perfect graphitic structure of the former.
CORROSION INHIBITION OF FLAKY ALUMINIUM BY SOL-GEL COATINGS OF MTES AND TEOS
Kun Chen, Lianfu Zheng, Pihui Pi, Xiufang Wen, View Paper Zhiqi Cai, Shouping Xu, Jiang Cheng, Zhuoru Yang, May 2012
For the purpose of corrosion inhibition of aluminium pigments in corrosive media, encapsulated flaky aluminium powders were prepared through the procedure of sol-gel with tetraethoxysilane(TEOS) and methyltriethoxysilicane?MTES?as precursors. The influences of the precursor, ammonia, deionized water dosages, reaction temperature and time were investigated. Under the optimum condition, the efficiency of corrosion inhibition achieved 97.2% in acid media of pH 1. The analysis with Fourier transformation infrared spectroscopy(FTIR), scanning electron microscopy(SEM) and X-ray photoelectron spectroscopy(XPS) showed that both TEOS and MTES hydrolyzed and condensed at the same time to be able to form a dense netlike sol- gel layer on the surface of aluminium pigments. The corrosion resistance of aluminum pigments encapsulated by hybrid coating film of TEOS and MTES was compared with that of aluminum pigments only by TEOS or by MTES. The hybrid coating film formed from TEOS and MTES showed more excellent corrosion resistance, due to its compactness and surface methyl groups which have excellent hydrophobic capability.
POLYMERIC HEAT DELIVERY SYSTEM
Maziyar Bolourchi, May 2012
Polymers are generally known for their excellent insulative properties. The addition of carbonaceous fillers within a polymer matrix can impart electrical and thermal properties making them good conductors. The resulting composites can be used in various applications including heaters/heating elements, for which resistive metals have been the materials of choice. The advantages of using such composites include cost reduction, chemical resistance, lighter weight, and flexibility to easily design and fabricate complex three- dimensional shapes via injection molding. For this work, various conductive thermoplastic composites were investigated as heating elements utilizing the mechanisms of Joule heating. First, composites and test specimens were prepared via melt extrusion and injection molding respectively. Thereafter, electrical and thermal properties were characterized using techniques developed in house. Results from experiments indicated significant advantages in using semi-crystalline polymers as matrices due to the superior electrical properties at equivalent filler loading. It was also determined that heating rate and maximum/plateau temperature were mainly a function of specimen resistance (formulation parameter) and voltage. Additionally, it was demonstrated that it is possible to develop polymeric heaters with operating temperatures up to 200°C. Moreover, these composites have self-regulating thermal characteristics different than the positive temperature coefficient mechanisms seen in olefin-based polymeric heaters.
STUDY ON PREPARATION AND PROPERTIES OF POLYLACTIDE/GRAFTED SILICA NANOCOMPOSITES
Bin-yi Chen, Xin Jing, Zhi-gang Hu, Hai-bin Zhao, Xiang-fang Peng, May 2012
In this article, epoxy resin with silane coupling agent and bisphenol A epoxy resin were used to graft nanosilica. A comparative study of PLA/nanosilica composites prepared by grafted nanosilica was conducted. The properties were characterized by mechanical properties, FTIR, DSC and SEM. It confirmed that the functional groups has been successfully grafted onto nanoparticles, and improve the properties of PLA. Results show that the nanocomposites with bisphenol A epoxy resin obtain the better properties.
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