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
PHOTO-INDUCED FOAMING OF UV CURING MONOMER / POLYMER BLEND WITH CO2
Akiyoshi Kajii , Shuhei Okumura , Kentaro Taki, May 2008
Cross-linking of a UV-curing monomer was utilized to make bubbles in a polystyrene matrix. The UV-curing monomer was instantly polymerized and cross-linked by exposure to UV light. Excess heat was produced during the polymerization, which was utilized to induce bubble nucleation in the CO2-saturated polymer. The polymerization of UV curing monomer formed a highly cross-linked structure which suppressed the bubble growth. The resulting foam contained 20 micron cells at 1 x 108 /cm3.
ADHESION PROMOTION USING FLAME PLASMA SURFACE TREATMENT
Joseph DiGiacomo, May 2008
The converting industry uses a significant amount of polyolefins from polyethylene coated paper board to metalized paper & film as well as polyolefin thin films.
DEVELOPMENT OF MELT-MODULATION TECHNOLOGY FOR ENHANCED INJECTION MOLDING
Akapot Tantrapiwat , John P. Coulter, May 2008
An improved mechanical apparatus and control method to enable enhanced melt modulation during injection molding has been developed and evaluated. As part of this new actuators were designed with the objective of decreasing both the size and cost relative to previously explored melt modulation systems. In addition different control techniques were applied in order to enhance the system performance. The results show that significant improvements were realized but potential remaining challenges are also presented in the paper.
DEVELOPMENT OF MELT-MODULATION TECHNOLOGY FOR ENHANCED INJECTION MOLDING
Akapot Tantrapiwat , John P. Coulter, May 2008
An improved mechanical apparatus and control method to enable enhanced melt modulation during injection molding has been developed and evaluated. As part of this, new actuators were designed with the objective of decreasing both the size and cost relative to previously explored melt modulation systems. In addition, different control techniques were applied in order to enhance the system performance. The results show that significant improvements were realized, but potential remaining challenges are also presented in the paper.
THERMAL DEGRADATION OF FIBER-REINFORCED BIO-BASED RIGID POLYURETHANE FOAMS
Andres Garcia , Patricia Alvarado , Maria Sibaja , Guillermo Jimenez , Jose Vega, May 2008
Rigid polyurethane (PU) foams were prepared by a multi- step procedure using a polyol blend of poly(ethylenglycol) PEG-200/pineapple molasses and 4 4'-diisophenylmethane diisocyanate (MDI) with a NCO/OH ratio of 1.2. Such material was reinforced with fibers from banana rachis with a fiber composition ranging from 18% to 40% wt.Thermal and themooxidative degradation properties of these composites were assessed. Thermal degradation of PU60 showed the highest polymer lifetime values.
RIGID COMPOSITE MATERIALS FROM OLIVE BRUSH SEED AND UNSATURATED POLYESTER RESIN
L. Jimenez , M. Sibaja , P. Alvarado , J. Vega , Jimenez , M.F. Barreiro , C.A.Cateto , M. Lopretti, May 2008
A composite material using unsaturated commercial polyester resin (UPE) and olive brush seed (OBS) was prepared. OBS was treated with sodium hydroxide and maleic anhydride (MAN) and subsequently utilized in a proportion of 35 wt.% to prepare a composite material. These materials were evaluated in terms of moisture absorption surface density and mechanical properties such as flexure and tensile tests.
IMPROVING THE THERMAL CONDUCTIVITY OF EPOXY HYBRID NANOCOMPOSITES FOR AEROSPACE APPLICATIONS
Siva Movva , Dante Guerra , Zhi-qi Cai , Yunior Hioe , L. James Lee , Jose Castro, May 2008
The poor thermal conductivity of polymer based composites has long been a deterrent to their increased use in high end aerospace applications. In this study the thermal conductivity of Epoxy-Carbon fiber composites is improved dramatically by a novel method of incorporating carbon nanoparticles into the system. A comprehensive study of the preparation and properties of the highly thermally conductive Epoxy-Carbon fiber-Carbon nanofiber composites is presented.
INVESTIGATION OF EVOH/KAOLINITE NANOCOMPOSITE FILMS
Danielle Froio , Sarah Schirmer , Jo Ann Ratto , Matthew Bernasconi , Christopher Thellen , Scott Winroth, May 2008
Two grades of ethylene vinyl alcohol copolymer (EVOH) were compounded with kaolinite nanoparticles at a loading level of 5%, and subsequently extruded into blown and cast monolayer films. Films were analyzed for oxygen and water vapor barrier, mechanical performance and thermal properties. The films showed slight changes in thermal stability, no significant improvement in barrier properties, a decrease in Young's modulus and no change in thermal properties such as melt and glass transition temperature.
EFFECT OF THE MOLDING PROCESS OVER THE ADJUSTABLE PARAMETERS IN CONSTITUTIVE EQUATIONS
R. Morales , O. Santana, May 2008
The mission of this study is to determine the effect of the orientation induced during the transformation process in the adjustable parameters of the constitutive equations for PP. In the hot tensile test different thermoforming conditions were simulated by changing oven temperature (sheet temperature) and crosshead speed (plug speed).Stressƒ??strain relations were derived. The model used involved eight adjustable parameters considering the effect of the process condition and process orientation.
TOWARDS QUALITY PRODUCTS FROM BIO-BASED PLASTICS
Rolf Koster, May 2008
The importance of three inter-dependent factors, i.e., (1) materials, (2) manufacturing, and (3) design and engineering, is generally recognized. All factors are indispensable and equally important for product development. Manufacturing is often the least structured factor and many designers and materials experts do not consider themselves capable to deal with it. Fortunately, expertise is sufficiently available and the best professionals are able to utilize plastics expertise properly in collaborative product development.
THE EFFECTS OF GRADUATED VERSUS CONSTANT RUNNER DIAMETERS ON FILLING AND PACKING OF A PLASTIC PART IN INJECTION MOLDING
Gregory L. Swanson , Matthew Weller, May 2008
This paper presents a study of the effects of various cold runner systems on filling and packing of a plastic part in injection molding. A comparison between graduated and constant runner diameters was the main focus of the paper. The study centered on the battle between minimizing runner volume and minimizing pressure drops. While many theories exist supporting one runner system over another this research attempted to collect enough data to prove when each should be used.
BIO-COMPATIBLE STRUCTURAL HYDROGEL CATHETER MATERIAL
Scott M. Epstein, May 2008
A new novel process that will produce a structural hydrogel catheter has been developed (1) resulting in biocompatible architecturally stable all hydrogel devices which can be used as an alternative to conventional TPE’s.
FAILURE ANALYSIS OF A PLASTIC SLIDE VALVE ASSEMBLY
Ahamed Shabeer, May 2008
Premature cracks were observed during service in the slide valve assembly molded from an acrylonitilebutadiene- styrene resin. The investigation focused on the determination of nature and cause of the failure. The results obtained during the evaluation indicated that the failure was due to environmental stress cracking which occurred as a consequence of the presence of the residual stress and the stress cracking agent. This paper will focus on the testing used to characterize the failure mode and identify the cause of the cracking of the slide valve assembly.
FAILURE ANALYSIS OF A PLASTIC SLIDE VALVE ASSEMBLY
Ahamed Shabeer, May 2008
Premature cracks were observed during service in the slide valve assembly molded from an acrylonitilebutadiene- styrene resin. The investigation focused on the determination of nature and cause of the failure. The results obtained during the evaluation indicated that the failure was due to environmental stress cracking, which occurred as a consequence of the presence of the residual stress and the stress cracking agent. This paper will focus on the testing used to characterize the failure mode and identify the cause of the cracking of the slide valve assembly.
MOLECULAR DYNAMICS SIMULATOIN OF VISCOELASTIC PROPERTIES AND SLIP BEHAVIOR OF THIN FILMS OF N-HEXADECANE IN THE SHEAR FLOW
Chen-Chieh Wang , Rong-Yeu Chang, May 2008
We investigate the viscoelastic properties of chain molecules (n-hexadecane) under steady state and oscillatory shear flow of ultra thin films by molecular dynamics simulation. The stress vs. strain rate diagram of the oscillatory shear flow system is used to determine the range of linear viscoelasticity. In addition interfacial slip is observed and discussed in both cases. The critical shear stress at which slip occurs is also found in our simulation.
RELATION BETWEEN BUBBLE STABILITY IN THE FILM BLOWING PROCESS AND MFI
Erika Palacios-Aguilar , Leonardo Cortés-Rodríguez , Jaime Bonilla-Ríos, May 2008
Several HDPE resins with different bubble film stability were tested in a melt flow indexer using the typical die (L = 8 mm D = 2.095 mm) and a zero die (L = 1.3 mm D = 2.095 mm) at two different loads (21.6 kg and 5 kg). A direct correlation was found between the MFI results and the bubble stability.
RELATION BETWEEN BUBBLE STABILITY IN THE FILM BLOWING PROCESS AND MFI
Erika Palacios-Aguilar , Leonardo Cortés-Rodríguez , Jaime Bonilla-Ríos, May 2008
Several HDPE resins with different bubble film stability were tested in a melt flow indexer using the typical die (L = 8 mm, D = 2.095 mm) and a zero die (L = 1.3 mm, D = 2.095 mm) at two different loads (21.6 kg and 5 kg). A direct correlation was found between the MFI results and the bubble stability.
ELIMINATION OF DEFECTS FROM INJECTION MOLDED POLYSTYRENE PARTS VIA SCREW MODIFICATIONS
Mark A. Spalding , Joseph R. Powers, May 2008
Many injection molded part defects are caused by improper screw designs. Elimination of the defect and optimization of the process can often be performed via simple modifications to the screw. A case study is presented where a splay defect was caused by a screw with a low compression ratio with regions where resin can stagnate and degrade and with a limited melting capacity. Modification of the screw eliminated the defects and decreased the cycle time by 8% an improved the plant capacity by 14%.
ELIMINATION OF DEFECTS FROM INJECTION MOLDED POLYSTYRENE PARTS VIA SCREW MODIFICATIONS
Mark A. Spalding , Joseph R. Powers, May 2008
Many injection molded part defects are caused by improper screw designs. Elimination of the defect and optimization of the process can often be performed via simple modifications to the screw. A case study is presented where a splay defect was caused by a screw with a low compression ratio, with regions where resin can stagnate and degrade, and with a limited melting capacity.Modification of the screw eliminated the defects and decreased the cycle time by 8% an improved the plant capacity by 14%.
AN ENGINEERING APPROACH TO DESIGNING PLASTICATING SCREWS FOR SINGLE-SCREW EXTRUDERS
Mark A. Spalding , Gregory A. Campbell, May 2008
An engineering approach for the design of plasticating screws is presented with a case study. The approach uses a combination of experimental data and numerical simulations.
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