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
CALCULATION AND ANALYSIS OF MOLD COST FOR INJECTION MOLDING VIA A MOLD DESIGN NAVIGATION SYSTEM
Shia-Chung Chen , Chia-Yen Tseng , Jeng-Li Shiu1, May 2010
Low cost and quality are essential demands in mold and molding manufacturing. Mold cost calculations can be classified into four parts: material, manufacture, overhead, and profit. This research develops a navigation system that can provide a calculation and analysis of mold prices. The difference between the actual sample price and the calculated price is roughly 6%. Via the mold price navigation system, customer and mold vendor engaged in detailed discussions and obtain a good mold price estimate. The system not only greatly helps the inexperienced designer but also provides a feasible mold price calculation conception and a collaborative environment for the design process.
PROCESSING AND PROPERTIES OF ELECTRO-CONDUCTIVE CARBON NANOTUBE COMPOSITES IN HIGH PERFORMANCE ENGINEERING POLYMERS
Jun Taniguchi, Noriyuki Unno, Yasuhiro Kamiya, Nobuji Sakai, Takeshi Ohsaki, May 2010
Development of electro-conductive polyamide 4.6 (PA4.6) and polyamide 4.6/poly(phenylene sulfide) blend (PA4.6/PPS) incorporating multiwall carbon nanotube (CNT) were first reported in this work. PPS/CNT was also investigated. The CNT composites exhibited electrical conductivity at remarkably low CNT content, displayed a volume electrical percolation threshold at < 0.9 wt% CNT. At only 1 wt%, all the three composites would already register 103 Ohm?úcm volume resistivity. The required surface electrical percolation to reach 107 Ohm ?ú sq-1 for the PA4.6, PPS and PA4.6/PPS blend was 1.4, 2.0 and 0.9 wt% respectively. A co-continuous morphology observed for the PA4.6/PPS blend would explain for its extremely low percolation. The melt crystallisation behavior of the polymers altered appreciably in the presence of CNT. PA4.6 crystallised at some 12 ?øC higher, from 257.5 ?øC to 269.5 ?øC. The full crystallisation half-time of PPS was reduced by nearly 2/3 from 110s to 38s, while its peak crystallising temperature was raised by some 46 ?øC from 188.5 ?øC to 235 ?øC. The small doublet melting peak of the virgin PA 4.6/PPS blend would merge into single peak in its composite that could indicate the blend compatibility was more improved in the presence of CNT. Furthermore, the PA4.6/PPS/CNT blend showed least mould shrinkage and smoothest injection moulded surface among all the composites investigated.
THREE DIMENSIONAL NANO IMPRINT LITHOGRAPHY USING PHOTO-CURABLE RESIN
Jun Taniguchi , Noriyuki Unno , Yasuhiro Kamiya , Nobuji Sakai , Takeshi Ohsaki, May 2010
Three dimensional (3D) Nanoimprint Lithography (NIL) was carried out using photo-curable resin. NIL process was as follows: first, a fabricated NIL mold was coated with an anti-sticking layer. Then, a ultraviolet (UV) photo-curable resin was dispensed onto cleaned glass slides or polyethylene terephthalate (PET) films. Next, the mold was pressed against the resin on the substrate. The photo-curable resin was then exposed of UV light. The mold was then retracted, leaving behind a replica of its pattern. Using 3D mold with markedly uneven, evaluation of photo-curable resin was possible and it was found that weaker intermolecular force monomers improved transfer and release properties.
STUDY ON PACKING EFFECTS ON THE PART SHRINKAGE MOLDED BY EXTERNAL GAS-ASSISTED INJECTION MOLDING PROCESS
Shia-Chung Chen , Yi-Chang Lin , Shih-Tsun Huang , Hsin-Yi Huang, May 2010
External gas-assisted injection molding (EGAIM) has been receiving attention for its improvement of surface quality. However, compared with gas-assisted injection with gas penetration into the melt core, the packing effects of EGAIM on the pressure variation within the mold cavity and the part shrinkage have not been investigated. In this study, the pressure differential between core and cavity is about 3.04 bar. In addition, the required gas packing pressure (90 bar) is much lower than that of conventional packing pressure (1000 bar) in achieving identical shrinkage. With increased gas packing pressure and gas packing time, the shrinkage can be further reduced. However, the gas delay time for shrinkage is related to the pressure inside the mold.
ADVANCED AEROSPACE COMPOSITES USING AN AROMATIC THERMOSETTING COPOLYESTER MATRIX – IMPROVED THERMAL FATIGUE
Zeba Farheen , Abdul Samad , James Economy, May 2010
The potential superiority of ATSP (aromatic thermosetting copolyester) matrices compared to conventional epoxies for aerospace composites is discussed. Preparation and characterization of carbon fiber/ATSP composites are described. In this paper we demonstrate that ATSP oligomers display liquid crystalline behavior which was identified using optical microscopy with cross-polarizers. We also describe how ATSP tailored to have a liquid crystalline structure has reduced stresses at the fiber/matrix interface and better thermal fatigue resistance compared to epoxy.
ADVANCED AEROSPACE COMPOSITES USING AN AROMATIC THERMOSETTING COPOLYESTER MATRIX ƒ?? IMPROVED THERMAL FATIGUE
Zeba Farheen , Abdul Samad , James Economy, May 2010
The potential superiority of ATSP (aromatic thermosetting copolyester) matrices compared to conventional epoxies for aerospace composites is discussed. Preparation and characterization of carbon fiber/ATSP composites are described. In this paper, we demonstrate that ATSP oligomers display liquid crystalline behavior which was identified using optical microscopy with cross-polarizers.We also describe how ATSP tailored to have a liquid crystalline structure has reduced stresses at the fiber/matrix interface and better thermal fatigue resistance compared to epoxy.
THE EFFECTS OF COMPATIBILIZERS IN INJECTION MOULDED WOOD PLASTIC COMPOSITES
Wentao Zhai, Siu N. Leung, Hani E. Naguib, Chul B. Park, May 2010
The aim of this work was to investigate the various effects of compatibilizers on different aspects. The polypropylene based WPC, containing different compatibilizers, were produced via compounding and injection molding. Testing for tensile and impact strengths as well as for MFR and shrinkage was carried out subsequently. We found, that the presence of a compatibilizer not only enhances tensile strength (up to 80%, depending on wood and compatibilizer concentration), but also influence other properties, e.g. shrinkage and MVR are increasing with increasing compatibilizer concentration. Furthermore, with the help of a saturation model, the effects of different compatibilizer grades, exhibiting different maleic anhydride content as well as different viscosity, were evaluated to get deeper insight in the mechanisms.
PREPARATION OF MICROCELLULAR POLY(ETHYLENE-CO-OCTENE) RUBBER FOAM USING SUPERCRITICAL CO2 TECHNOLOGY
Wentao Zhai , Siu N. Leung , Hani E. Naguib , Chul B. Park, May 2010
In the past three decades there has been great advancement in preparing microcellular thermoplastic polymer foam. However little attention is paid to thermoplastic elastomer. In this study microcellular poly(ethylene-co-octene) (PEOc) rubber foams with a cell density of 2.9×1010 cells/cm3 and cell size of 1.9 ?m are successfully prepared by using CO2 as the physical blowing agent with a batch foaming process. Microcellular PEOc foams exhibit a well defined closed cell structure uniform cell size distribution and formation of unfoamed skin at low foaming temperatures. Their difference from thermoplastic foam is the foam shrinkage in the atmosphere due to the elasticity of polymer matrix. The effect of melt flow rates on the cell growth process is investigated by changing the foaming conditions.
PREPARATION OF MICROCELLULAR POLY(ETHYLENE-CO-OCTENE) RUBBER FOAM USING SUPERCRITICAL CO2 TECHNOLOGY
Wentao Zhai , Siu N. Leung , Hani E. Naguib , Chul B. Park, May 2010
In the past three decades, there has been great advancement in preparing microcellular thermoplastic polymer foam. However, little attention is paid to thermoplastic elastomer. In this study, microcellular poly(ethylene-co-octene) (PEOc) rubber foams with a cell density of 2.9??1010 cells/cm3 and cell size of 1.9 ?¬m are successfully prepared by using CO2 as the physical blowing agent with a batch foaming process. Microcellular PEOc foams exhibit a well defined closed cell structure, uniform cell size distribution, and formation of unfoamed skin at low foaming temperatures. Their difference from thermoplastic foam is the foam shrinkage in the atmosphere due to the elasticity of polymer matrix. The effect of melt flow rates on the cell growth process is investigated by changing the foaming conditions.
STIFF, HIGHLY DAMPING THERMOPLASTIC POLYURETHANE NANOCOMPOSITES VIA SIMPLE, SCALABLE PROCESSING
Erik Dunkerley , Daniel F. Schmidt, May 2010
Nanocomposites comprising a high percentage of inorganic layers and a low percentage of organic binder have been reported to exhibit remarkable physical properties due to high levels of organization, connectivity and phase morphology. We report the preparation and characterization of a system of this type consisting of montmorillonite layers and thermoplastic polyurethane (TPU) binder. Transparent sheets were prepared and characterized via SEM for structure, TGA and DSC for thermal properties, and DMA for mechanical response. These materials are stable, robust, and exhibit interesting combinations of stiffness and damping capacity.
MONITORING THE EFFECT OF OPERATING CONDITIONS ON MELT TEMPERATURE HOMOGENEITY IN SINGLE-SCREW EXTRUSION
C. Abeykoon, M. McAfee, K. Li, A. L. Kelly, E. C. Brown, May 2010
Delivery of a melt which is homogenous in composition and temperature is paramount for achieving high quality extruded products. However, melting stability can be difficult to determine via typical melt pressure and thermocouple instrumentation. This can result in inefficient operation through non-optimized operating conditions or extruder screw geometry. In this work, melt temperature homogeneity in a single screw extruder is investigated experimentally using a thermocouple mesh technique. The effect of barrel temperature settings and screw speed on die melt temperature homogeneity is investigated. Inferential methods of determining melting stability in-process are investigated with the aim of developing modeling and control techniques to improve process quality and efficiency.
PS FOAMS BLOWN FROM HFC-134a/HFC-32 BLENDS: PROCESSING BEHAVIOR
Michel F. Champagne , Richard Gendron , Jacques Tatibouët, May 2010
Manufacturing of extruded polystyrene (XPS) foam insulation boards is currently based on weak ozone depleting gases. Mixtures of blowing agents are actually seen as one of the most promising solutions to ozonedepleting substances phase-out. This paper investigates various blowing agent formulations based on mixtures of hydrofluorocarbons HFC-134a (1,1,1,2-tetrafluoroethane) and HFC-32 (difluoromethane). The study focuses on the rheological (plasticization) and degassing (solubility) behaviors of the formulations, as measured on-line during foam extrusion. Rules of mixing for such blends of HFCs are proposed based on the relative contribution of each component to the overall processing behavior.
SOFT POLYURETHANE FOAMS AS CARTILAGE REPLACEMENT: PROCESSING BEHAVIOR AND BIOCOMPATIBILITY
Michel F. Champagne , Sashka Dimitrievska , Richard Gendron , Martin N. Bureau, May 2010
Massively invasive surgery is often the only cure for the worst cases of cartilage-related diseases. In an effort to physiologically mimic human joints, 4 biomedical thermoplastic polyurethanes (TPU) differing in glass transition temperature, modulus and wettability were foamed using a CO2-based solid-state process. Human cartilage mechanical behavior was closely matched by low density foams of the softest TPU investigated. In vitro osteoblastic studies showed improved cell differentiation, activity and proliferation; all suggestive of TPU foans potential osteointegration. The superior bioactivity and cartilage-matching mechanics make the TPU foam a promising cartilage replacement.
INFLUENCE OF PROCESSING CONDITIONS AND POLYMER CHARACTERISTICS ON SURFACE TOPOGRAPHY OF SMALL BORE TUBES
Peng Xiang-fang, Peng Jun, Xie Xiao-li, Turng Lih-Sheng, May 2010
The topography of the inner surface of small bore extruded tubes used in fluid handling applications can affect flow rates, fluid turbulence and biofilm adherence. Quantitative surface roughness analysis of tubes manufactured from different polymers has shown that the inner surface topography is related to the polymer molecular variables, rheological properties and extrusion processing conditions. Surface energy analysis of these surfaces has also been shown to be related to polymer type as well as surface roughness.
EFFECT OF ORGANOCLAY ON THE MECHANICAL PROPERTIES AND CRYSTALLIZATION BEHAVIORS OF INJECTION-MOLDED PP/ ABS/ MONTMORILLONITE NANOCOMPOSITES
Peng Xiang-fang , Peng Jun , Xie Xiao-li, May 2010
The mechanical properties and crystallization behaviors of PP/acrylonitrile-butadiene-styrene/organic montmorillonite nanocomposites (PP/ABS/OMMT) were studied. It was shown that compatilizer PP-g-MAH not only improved the compatibility of PP/ABS but also promoted the dispersity of OMMT particles in continuous phase PP and dispersed phase ABS. In addition PP was reinforced and toughened by both layered silicate OMMT nanoparticles and ABS. The blend weight ratio of PP/ABS/OMMT which was 85/15/2 wt % had a concerted effect on toughening. OMMT nanoparticles also increased crystallization temperature and crystallinity.
EFFECT OF ORGANOCLAY ON THE MECHANICAL PROPERTIES AND CRYSTALLIZATION BEHAVIORS OF INJECTION-MOLDED PP/ ABS/MONTMORILLONITE NANOCOMPOSITES
Peng Xiang-fang , Peng Jun , Xie Xiao-li , Turng Lih-Sheng, May 2010
The mechanical properties and crystallization behaviors of PP/acrylonitrile-butadiene-styrene/organic montmorillonite nanocomposites (PP/ABS/OMMT) were studied. It was shown that, compatilizer PP-g-MAH not only improved the compatibility of PP/ABS, but also promoted the dispersity of OMMT particles in continuous phase PP and dispersed phase ABS. In addition, PP was reinforced and toughened by both layered silicate OMMT nanoparticles and ABS.The blend weight ratio of PP/ABS/OMMT, which was 85/15/2 wt %, had a concerted effect on toughening.OMMT nanoparticles also increased crystallization temperature and crystallinity.
AUTOMATED OPTIMIZATION OF INJECTION MOLD COOLING CIRCUIT WITH OPTIMIZATION TOOL PIANO
Brian P. Grady, May 2010
In order to assure the part quality in the part design step, it is desirable to optimize the cooling circuit prior to the mold design step. In the environment of frequent design changes, a way to optimize automatically the cooling circuit in a short period of time is necessary. In this work, an automated optimization of the cooling circuit was examined with a commercial optimization tool, PIAnO. The optimization technique is useful largely for large parts such as instrument panels and bumpers. The objective function is the deviation of temperature difference from a target mold surface temperature.
PLASTICS INDUSTRY INNOVATION: HOW TO SURVIVE AND THRIVE IN A RECESSION
Brian P. Grady, Abhijit Paul, Warren T. Ford, May 2010
In this paper, we will discuss several companies who have not seen recessions as a deterrent to innovation but an opportunity. Using a case study format, we will discuss four companies that have innovated in a recessionary environment. We will derive the lessons learned and offer some recommendations as to ƒ??how toƒ? look for the silver lining in an economic downturn. The objective of this paper is to present examples of companies that re-positioned for growth during an economic downturn. In two of the cases, an innovative business grew out of adversity. The third is a new company that was able to identify a technology developed earlier but eventually abandoned due to a lack of a market. The last invested while its competitors contracted. Due to the poor economy, most of us are experiencing a drop in our business and are looking for ways to reposition our businesses. Our businesses are down as much as 50% from prior years. We have cut our costs, reduced our payrollsƒ??what do we do nowƒ?? The following four companies are examples of what can be done to innovate in a recessionary environment. The following table shows the types of business segmentation opportunities.
POLYMER DYNAMICS IN SINGLE-WALLED CARBON NANOTUBE POLYMER COMPOSITES
Brian P. Grady , Abhijit Paul , Warren T. Ford, May 2010
A 100 000 g/mol polyethylene molecule has a crosssection of about 0.5 nm and a contour length of about 0.9 ?m. A typical single-walled carbon nanotube (SWCNT) has a cross-section of about 1 nm and a contour length of about 1 ?m. The critical difference from a physics perspective between these two molecules is that the persistence length of the former is about 0.6 nm and the persistence length of the latter is reported as ? 30 ?m.1 One can make a similar comparison between SWCNTs and liquid crystalline polymer molecules; in this case the key difference is that the length of the former is much larger than the length of the latter. This paper presents what is believed to be a synergistic type of behavior that is possibly related to the similarity in size of the two high aspect-ratio materials the fact that single-walled carbon nanotubes can increase the jump in heat capacity at the glass transition. Other measurements involving the behavior of fictive temperatures and activation energies measured from calorimetric studies are also given.
POLYMER DYNAMICS IN SINGLE-WALLED CARBON NANOTUBE POLYMER COMPOSITES
Brian P. Grady , Abhijit Paul , Warren T. Ford, May 2010
A 100,000 g/mol polyethylene molecule has a crosssection of about 0.5 nm and a contour length of about 0.9 ?¬m. A typical single-walled carbon nanotube (SWCNT) has a cross-section of about 1 nm and a contour length of about 1 ?¬m. The critical difference from a physics perspective between these two molecules is that the persistence length of the former is about 0.6 nm and the persistence length of the latter is reported as ƒ?? 30 ?¬m.1 One can make a similar comparison between SWCNTs and liquid crystalline polymer molecules; in this case the key difference is that the length of the former is much larger than the length of the latter. This paper presents what is believed to be a synergistic type of behavior that is possibly related to the similarity in size of the two high aspect-ratio materials, the fact that single-walled carbon nanotubes can increase the jump in heat capacity at the glass transition. Other measurements involving the behavior of fictive temperatures and activation energies measured from calorimetric studies are also given.
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