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
SOFT THERMOPLASTIC POLYURETHANES
Donald Meltzer, May 2008
The synthesis and physical properties of soft plasticizer-free thermoplastic polyurethanes (TPUs ) exhibiting durometers below 70A on the Shore scale have been investigated. The TPUs have been further characterized in terms of their thermal and tensile characteristics, set and tear properties as well as density. By employing hydrocarbon polyols along with suitable chain extenders, aromatic TPU with specific gravity less than 1.0, that exhibit acceptable physical properties and exhibit low compression set characteristics, have been prepared. Furthermore, these TPUs are hydrophobic, an unusual characteristic for a TPU, which suggests that they could be useful for applications where TPUs would not normally be considered, e.g., water barriers.
EVALUATION OF MULTI-SAMPLE MICRO-CAPILLARY RHEOMETER
Doyoung Moon , Anthony J. Bur , Kalman B. Migler, May 2008
We present a Multi-sample Micro-capillary Rheometer (MMR) which is capable of measurements over a broad range of temperatures viscosities and shear rates. The instrument is simple as the flow is generated by external gas pressure and the shear rate is measured optically. We test the MMR against two National Institute of Standards and Technology (NIST) Standard Reference Materials (SRMs) three low viscosity standards and one commercial polymer (Polydimethlysiloxane Polyisobutylene solution Oils and Polystyrene) and report a high level of accuracy and precision. This instrument will be particularly useful as a combinatorial method and in cases of limited material quantity (typical sample size 20 ?¬L). The dynamic range of the instrument is eightorders of magnitude in viscosity and four orders of magnitude in shear rate.
IMPROVED PROPERTIES AND COST EFFICIENCIES OF CYCLIC OLEFIN COPOLYMER ENHANCED FORMING FILMS
Paul D. Tatarka, May 2008
Cyclic olefin copolymers (COC) can provide film producers and packaging converters with an opportunity to create thermoforming films. COCs are amorphous thermoplastics with excellent moisture barrier high temperature stability and stiffness. Mono- and multi-layer examples of LLDPE-based forming films compared against commercially available products clearly demonstrate how well the addition of COC improves physical properties thermoforming and packaging performance. COC improves material distribution of LLDPE formed trays. These improvements enable the formed tray to withstand higher crushing force. Enhanced performance permits possibility of down gauging.
APPLICATION OF THE HAMMETT ACIDITY FUNCTION FOR THE EVALUATION OF RESINS RESISTANCE
Valery G. Makarov , Rakhil M. Sinelnikova , Pavel V. Glukhovskiy, May 2008
Chemical resistance of resins determines the lifetime of plastic materials. Chemically stable resins with ester groups undergo the hydrolysis in acidic environment.This hydrolysis is catalyzed by hydronium ions.The Hammett acidity function determines the concentration of hydronium ions in concentrated acids and their mixtures.This function can be used for material evaluations in laboratory testing and specific industrial environments.We used this approach to evaluate the chemical resistance of Dion 9100 (epoxyvinylester based resin) and Polilate 250 (unsaturated isophtalicpolyester based resin).
ADVANCED COMPATIBILITY MATRICES BY MULTI-COMPONENT INJECTION MOLDING PROCESS
M. Schuck , I. Kühnert , E. Schmachtenberg, May 2008
The principles of materials compatibility for joining of plastics using multi-component injection molding have been investigated. In order to expand compatibility matrices the influence of processing transient and pretreatment parameters on the bonding strength has been identified. The Experimental approach has included the determination of the influences of in-line-plasmapretreatment melt temperature on the contact zone and the surface contamination. Electron spectroscopy surface tension electron microscopy and IR-temperaturemeasurements have been used to analyze the contact surface.
SIMULATIONS AND EXPERIMENTAL STUDIES OF INTERFACE DISTRIBUTION AND BIRIFRINGENCE IN THE SEQUENTIAL CO-INJECTION MOLDING OF AMORPHOUS POLYMERS
N. H. Kim , A. I. Isayev, May 2008
2D numerical simulations of the interface distribution and flow birefringence for combinations of PS PC and PMMA in sequential co-injection molding of a centergated disk were performed. A hybrid control volume/finite element/finite different method with modeling based on nonlinear viscoelastic constitutive equation and stressoptical rule was used. Free quenching was performed and thermal birefringence was measured. Interface distribution and birefringence in moldings were measured. The thermal birefringence is added to the flow birefringence to obtain the birefringence. The simulation results for the interface distribution and birefringence qualitatively match with experimental results.
SIMULATIONS AND EXPERIMENTAL STUDIES OF INTERFACE DISTRIBUTION AND BIRIFRINGENCE IN THE SEQUENTIAL CO-INJECTION MOLDING OF AMORPHOUS POLYMERS
N. H. Kim , A. I. Isayev, May 2008
2D numerical simulations of the interface distributionand flow birefringence for combinations of PS, PC andPMMA in sequential co-injection molding of a centergateddisk were performed. A hybrid control volume/finiteelement/finite different method with modeling based onnonlinear viscoelastic constitutive equation and stressopticalrule was used. Free quenching was performed andthermal birefringence was measured. Interface distributionand birefringence in moldings were measured. Thethermal birefringence is added to the flow birefringence toobtain the birefringence. The simulation results for theinterface distribution and birefringence qualitatively matchwith experimental results.
OPPORTUNITIES FOR PLASTICS MATERIALS AND PROCESSES FOR UNDER-THE-HOOD APPLICATIONS
Dr. Suresh Shah, May 2008
There is an increasing demand for light weight low system/part cost high fuel efficiency recyclability low manufacturing cost and freedom of parts consolidation for under the hood parts.This presentation will discuss state of the art for several key applications such as HVAC components radiator components fan-shroud assemblies/modules air intake manifolds engine (or ƒ??beautyƒ?) covers rocker panels and other multi-functional assemblies etc.Plastics have made significant inroads in valve covers and air-intake manifolds. In valve covers (also called rocker or cam covers) thermoplastics are replacing thermosets. Advances in thermoset materials will also be discussed. The reason for using other technologies other than conventional injection molding such as thermoforming blow molding water/gas injection molding etc. will be discussed for above mentioned applications. For example future air-intake manifolds may utilize laser welding to join two shell halves with less potential damage to sensitive electronics than with vibration welding.To reduce part weight technologies like thin wall molding microcellular foaming and nanocomposite molding will be discussed. There is a need for high flow materials with high temperature capabilities.Opportunities for several material families such as polyamide Polyolefinic materials PPS PPA etc are discussed. Integration need such as fan/shroud with partial or full front end module instrument module with HVAC integration cam cover with gasket and oil/air separator into one lower-cost module; air-intake manifold and rocker panel into a single multi-functional assembly. etc; will be briefly discussed.
DEVELOPMENT OF A PRESSURE DRIVEN MICRO-RHEOMETER
Younggon Son, May 2008
A pressure driven micro-rheometer was developed. It uses 80 mg of material to measure the viscosity of polymer melts at shear rates ranging from ten to several thousands s-1. The maximum shear rate can be extended to several 104 s-1 with 200 mg of sample. The main part of the rheometer consists of two sample reservoirs connected through a slit channel (H = 0.1 mm W = 1 mm L=5 mm) and two pistons. The double piston arrangement enables using the same material repeatedly by the reciprocating flow of the polymer melt from one reservoir to the other.In addition by using a very thin slit channel the viscosity of polymer melts can be measured over a wide range of shear rates whilst using only a small quantity of material.Measured viscosity was in good agreement with that by a capillary rheometer and it was found that slip is negligible in the slit die used in this study.
THE MECHANICAL/THERMAL PROPERTIES OF MICROCELLULAR INJECTION MOLDED POLY-LACTIC-ACID(PLA) NANOCOMPOSITES
Shyh-shin Hwang , Peming P. Hsu , Jui-pinYang , Ray-Guan Tsai, May 2008
This study investigated the influence of montmorillonite (MMT) content on the mechanical/thermal properties of microcellular injection molded Polylactide (PLA)/clay nanocomposites. Carbondioxide (CO2) was the blowing agent. The PLA/MMTnanocomposites were prepared by twin screw extrusion.The results showed that as MMT content is increased tensile strength impact strength and cell density decrease.This is caused by the speed degradation of PLA due to the addition of MMT. MMT decreases the crystallization temperature but increases the decomposition temperature of the nanocomposites. The XRD results showed that the layer spacing of the clay increases as MMT content increases. TEM pictures showed that the MMT is well dispersed within the PLA matrix.
EFFECT OF ORGANOCLAY ON THE MECHANICAL / THERMAL PROPERTIES OF MICROCELLULAR INJECTION MOLDED POLYSTYRENE-CLAY NANOCOMPOSITES
Shyh-shin Hwang , Sung-po Li , Ching-hsin Hu , Cheng-lung Lee, May 2008
An organically modified montmorillonite was compounded with polystyrene (PS) in a twin-screw extruder. The organoclay polystyrene nanocomposites were then injection molded by conventional and microcellular methods. Nitrogen was used as the blowing agent. The effect of organoclay content on the mechanical and thermal properties was investigated. The results showed that when the MMT content was 1 wt% the nanocomposites have maximum tensile strength wear resistance and cell density. Moreover the addition of organoclay increases the glass transition and decomposition temperature of the nanocomposites. The XRD results showed that the layer spacing of the nanocomposites decreases by comparison with the organoclay. TEM pictures showed that MMT is well dispersed within the PS matrix.
CONTROL OF DENSITY AND MODULUS IN DIE DRAWN PP COMPOSITES
P. Caton-Rose , I. M. Ward , G. Thompson , P D Coates, May 2008
Polymer chain orientation achieved through the die drawing process has been shown to significantly improve the mechanical properties of both filled and unfilled polymer products1. However inclusion of filler particles tends to result in localised cavitation and subsequent propagation which reduces stiffness enhancements. By tailoring production parameters such as rate temperature and geometry it is possible to control both the modulus and density of the final product to given specifications. Within this paper we demonstrate the effects of die angle and temperature on the final sample properties of a civil engineering product and their optimisation to manufacture a low density high stiffness component.
CONTROL OF DENSITY AND MODULUS IN DIE DRAWN PP COMPOSITES
P. Caton-Rose , I. M. Ward , G. Thompson , P D Coates, May 2008
Polymer chain orientation achieved through the die drawing process has been shown to significantly improve the mechanical properties of both filled and unfilled polymer products. However, inclusion of filler particles tends to result in localised cavitation and subsequent propagation, which reduces stiffness enhancements. By tailoring production parameters such as rate, temperature and geometry it is possible to control both the modulus and density of the final product to given specifications. Within this paper we demonstrate the effects of die angle and temperature on the final sample properties of a civil engineering product and their optimisation to manufacture a low density high stiffness component.
TEACHING MOLD DESIGN: FROM CONCEPT TO CREATION
Stephen Johnston , David Kazmer, May 2008
Traditionally mold design has been taught on a theoretical basis where student’s designs never leave the drawing board. Today’s computer aided manufacturing techniques allow for hands-on design projects. A junior level mold design engineering class was revised to include an intensive art-to-part project. Given constraints students designed new plastic parts manufactured the tooling using CAM software and CNC machining and injection molded prototype parts. In addition to mold design students learned machine tool practices and the difficulties associated with commissioning new tools. The project required considerable initial investment but was met with an overwhelmingly positive response.
TEACHING MOLD DESIGN: FROM CONCEPT TO CREATION
Stephen Johnston , David Kazmer, May 2008
Traditionally mold design has been taught on a theoretical basis where studentƒ??s designs never leave the drawing board. Todayƒ??s computer aided manufacturing techniques allow for hands-on design projects. A junior level mold design engineering class was revised to include an intensive art-to-part project. Given constraints, students designed new plastic parts, manufactured the tooling using CAM software and CNC machining, and injection molded prototype parts. In addition to mold design, students learned machine tool practices and the difficulties associated with commissioning new tools. The project required considerable initial investment, but was met with an overwhelmingly positive response.
ANALYSIS OF IN DIE CAVITATION DURING THE DIE DRAWING OF COMPOSITE MATERIALS
P. Caton-Rose , I. M. Ward , G. Thompson , P D Coates, May 2008
Combining molecular orientation of polymer chains with short glass fibre reinforcement has been shown to significantly improve material stiffness in the direction of orientation1. Replacement of the stiff glass fibres with inorganic fillers also has the capability of improving mechanical performance of oriented composites but at a reduced production cost. Orientation is achieved via a batch die drawing process 5 to 20 oC below the melt temperature of the polypropylene inorganic composite material. This experimental investigation has now been extended to consider cavitation around particulates within the composite material during the die drawing process using macroscopic and microscopic finite element models validated via image analysis and density measurements of actual drawn components. Within this paper we demonstrate the modelling route to achieve micro-scale predictions of cavitation based on a macroscopic analysis of the complete component through a technique known as submodelling.
ANALYSIS OF IN DIE CAVITATION DURING THE DIE DRAWING OF COMPOSITE MATERIALS
P. Caton-Rose , I. M. Ward , G. Thompson , P D Coates, May 2008
Combining molecular orientation of polymer chains with short glass fibre reinforcement has been shown to significantly improve material stiffness in the direction of orientation. Replacement of the stiff glass fibres with inorganic fillers also has the capability of improving mechanical performance of oriented composites but at a reduced production cost. Orientation is achieved via a batch die drawing process 5 to 20 oC below the melt temperature of the polypropylene inorganic composite material. This experimental investigation has now been extended to consider cavitation around particulates within the composite material during the die drawing process using macroscopic and microscopic finite element models validated via image analysis and density measurements of actual drawn components. Within this paper we demonstrate the modelling route to achieve micro-scale predictions of cavitation based on a macroscopic analysis of the complete component through a technique known as submodelling.
A STUDY OF USING FILLED PLASTIC BOTTLES AS CRASH BARRIERS
S.H. Masood, May 2008
This paper presents an experimental investigation on the capability of using commercially available plastic bottles as energy absorbing devices for safety crash barrier applications. The compression tests are conducted in vertical and horizontal orientations with bottles of various sizes and with a variety of filler materials such as air water foam sand and paper pulp and also with mixture of such fillers. Results are compared in terms of varying plastic bottle size bottle orientation and filler types.Results show that commercially available plastic bottles with proper orientation and appropriate filler materials are capable of absorbing significant amounts of crash energy.
DISPERSION OF FUNCTIONALIZED CARBON NANOFIBERS IN THERMOPLASTIC POLYURETHANES
Guillermo A. Jimenez , Sadhan C. Jana, May 2008
Carbon nanofibers - as received oxidized and functionalized with polyol - were mixed with thermoplastic polyurethanes (TPU) at the time of in situ synthesis in a chaotic mixer. The TPU was synthesized from polypropylene glycol butanediol and 4 4'-diphenylmethane diiocyanate. The degree of nanofiber dispersion was analyzed using hard segment hydrogen bonding. It was found that functionalized carbon nanofibers showed more interactions with hard and soft segments in TU. Consequently these fibers dispersed well promoted mixing between the hard and soft segment phases and prompted an increase of glass transition temperature.
FOAM INJECTION MOLDING OF CELLULOSE FIBER REINFORCED POLYPROPYLENE COMPOSITES
T. Kuboki , J.W.S. Lee , C.B. Park , M. Sain, May 2008
This paper investigates the effects of the fiber content and the processing conditions such as the shot size and the injection speed on the foaming behavior of injection molded composite foams made from cellulose fiber reinforced polypropylene. Composites are injection molded by using an advanced structural foam molding machine with a physical blowing agent N2. Foamed specimens are prepared with different injection speeds and void fractions while the mold pressure profile void fraction and foam morphology are characterized. The results suggest that there is an optimum fiber content for the cell morphology of injection molded composite foams made of cellulose fiber reinforced polypropylene.
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