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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3D SIMULATIONS OF A REACTIVE FLOW IN SCREW ELEMENTS OF CLOSELY INTERMESHING TWIN SCREW EXTRUDERS: CONVENTIONAL AND VARIABLE SPEED EXTRUDERS
The peroxide-initiated degradation of polypropylene in conveying screw elements of closely intermeshing twin screw extruders (COITSEs) is analyzed by means of a three-dimensional (3D) simulation approach. The simulations are implemented for a conventional and a special design screw element (from a variable speed extruder). Different values of peroxide concentrations and mass throughputs are implemented to analyze the reactive system of interest in terms of the specified extruder design.
TWIN SCREW EXTRUSION OF THERMOPLASTIC POTATO STARCH
Among starch species, potato tends to have a much narrower processing window in extrusion machinery for the preparation of thermoplastic starch compared to other common starch sources from corn or wheat. The present study demonstrates through a series of screw design refinements, a working approach to setting up a reasonable processing window of this starch type and discusses the issues involved. Finally the paper demonstrates through a series of trials with one of the optimal screw configuration, the influence of shear and formulation on final properties for the thermoplastic product.
THE FOAMABILITY OF POLYPROPYLENE COPOLYMER BLOWN WITH ARGON NITROGEN AND HELIUM
Due to environmental concerns research has been carried out to investigate the feasibility of using inert gases as blowing agents in plastic foaming processes.However the foamability of polypropylene copolymer blown with argon nitrogen and helium has not been reported previously. This paper investigates the nucleating powers of these gases to foam polypropylene copolymer by studying the polymeric foaming processes in situ.
EFFECT OF OMMT CHARACTERISTICS ON SCRATCH DEFORMATION BEHAVIOR OF POLYPROPYLENE TERNARY NANOCOMPOSITES
Compatibilized polypropylene (PP)/organically modified montmorillonite (OMMT) nanocomposites were prepared via melt intercalation. OMMTs with different gallery spacing were chosen. The effect of OMMT structure on scratch deformation behavior was investigated.Correlations between scratch deformation parameters with mechanical, thermal and melt flow behavior of the nanocomposites were established and discussed.
THE EFFECT OF ANNEALING ON DEFORMATION AND FRACTURE BEHAVIOR OF INJECTION MOLDED PLA
The effect of annealing on the deformation and fracture behavior of injection molded Poly (lactic acid) (PLA) was investigated. The behavior of as-molded amorphous PLA was changed from brittle to ductile by annealing above Tg (60?øC) for 5 min. On the other hand, the sample annealed above Tcr (re-crystallization temperature) showed brittle fracture.
MECHANICAL PROPERTIES OF SYNTACTIC FOAMS
Syntactic foams on epoxy and on vinyl esters were produced and tested. Different types of glass microballoons were used. Samples were tested on compression tension bending fracture toughness and on impact resistance. The influence of the type of microballoons their concentration and the type of polymer matrix properties was studied. Density and morphology studies were used for the control of technology. Results of experiments are compared with different theoretical models used for the properties prediction.
APPLICATION STUDIES ON THE EFFECT OF SIMPLIFIED FIBER ORIENTATION ON STRUCTURAL ANALYSIS
In structural analysis of the product with glass fiber reinforced material, anisotropic characteristics from fiber orientation have great influences on the analysis results. The fiber orientation results from injection molding CAE software are used to consider the effect, but the expense of the software and lack of knowledge for injection molding prevent structural analysis engineers from considering the anisotropic material properties. To simply apply the effects, new technology was developed. In this study, the process adapted and case studies are introduced.
PP/CO2 Volume Swelling from Measurement and Equations-of-state Predictions
The Pressure-Volume-Temperature (PVT) data for polymer/gas solutions is an important fundamental property in which accurate measurement has not been reported until recently. This paper presents the measured volume swelling of linear and branchedpolypropylene (PP) with CO2 under hightemperature and pressure conditions by using a new PVT measurement apparatus. Comparisons are made between the measured swelling data the Sanchez and Lacombe (SL) and Simha and Somcynsky (SS) equations-of-state (EOS) predicted values.
COLOR STABILITY OF TRANSPARENT HIGH HEAT POLYCARBONATE IN AUTOMOBILE LENS APPLICATIONS
Novel and versatile developments in automotive lighting applications demand new material solutions to meet industry requirements. Color stability of a new transparent high heat polycarbonate copolymer under thermal aging has been investigated. The magnitude and rate of color shift have been used to predict the long-term performance of these materials in automobile lens applications. The end use temperatures can be determined based on specific industry requirements.
STYRENIC COPOLYMERS CONTAINING OLIGO(OXY ETHYLENE) SIDE CHAINS
Novel styrenic copolymers containing oligo(oxyethylene) groups are designed, synthesized and characterized using different analytical techniques. While they are used as compatibilizers in engineering polymer blend systems they could potentially impart improved flow and surface properties e.g., antistatic, antidust properties.
A NEW FAMILY OF FLAME RETARDANT POLYMERS AND ADDITIVES
Polyphosphonates are a new family of polymeric, flame-resistant oligomers and polymers that can be used in demanding applications both as FR additives and stand-alone plastics. Polyphosphonate plastics have the highest LOI of any of the thermoplastic-processable polymers. These materials are inherently flame retardant and can be used in a broad variety of polymer systems, including thermoplastic and thermosetting. Being both halogen-free and polymeric, polyphosphonates are unique in the area of flame retardants.
INFLUENCE OF PROCESSING CONDITIONS AND POLYMER CHARACTERISTICS ON SURFACE TOPOGRAPHY OF SMALL BORE TUBES
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.
A UNIFIED MORPHOLOGICAL DESCRIPTION OF IONOMERS
A comprehensive description will be provided for ionic aggregates in ionomers for those cations that are strongly segregated (e.g. ionomers neutralized with transition metals). The fundamental structure of aggregates is planar, and the various morphologies that have been seen in TEM and suggested from SAXS data are due to rolling of the planes (e.g. similar to nanotubes) to reduce the number of edge atoms.
THE EFFECTS OF MOISTURE AND TEMPERATURE ON THE HIGH FREQUENCY DIELECTRIC PROPERTIES OF ENGINEERING THERMOPLASTICS
The Effects of Moisture and Temperature on the High Frequency Dielectric Properties of Engineering Thermoplastics
RESEARCHES ON MORPHOLOGY AND PROPERTIES OF POLYPROPYLENE/POLYAMIDE-6/ORGANOCLAY NANOCOMPOSITES
The mechanical properties and morphology of polypropylene/ polyamide-6/organoclay nanocomposites were studied. It was shown that the addition of clay improved impact strength and flexural strength but made little effort on tensile strength. Organoclay had influence on crystalline property of PP and PA6 and improved the compatibility of PP/PA6 blends.
BENCHMARKING FRACTOGRAPHIC FEATURES USING HOUSEHOLD PRODUCT FAILURES
Several failures that occurred to plastic products used at the home of the author were selected for study of their fracture surfaces. The failed parts included a bicycle fender a rack for drying sweaters and a magnetic refrigerator clip. All of the failed parts were fabricated from styrenic-based polymers. This paper will focus on connecting the known service conditions of the failed parts to the unique patterns observed on the fracture surfaces.
ULTRASOUND ASSISTED MELT PROCESSING OF LCP/CNF NANOCOMPOSITES
Ultrasound assisted twin screw extrusion process was developed to disperse carbon nanofibers (CNFs) in a polymer matrix. CNFs were separately added into the melt stage to reduce the breakage of CNFs and to avoid intense stresses in the feed zone. The effect of ultrasound and CNFs loading on die pressure, rheological, mechanical, electrical and morphological properties of liquid crystalline polymer (LCP) filled with 2-20 wt% CNFs was studied.Ultrasonic treatment caused a reduction in die pressure with decrease in electrical percolation threshold value of treated samples.
WEB-BASED NAVIGATING SYSTEM FOR MOLD- QUOTATION
This work is to make the quotation of injection mold to be easy and transparent. This web-based mold-quotation system is integrated with conceptual design in CAD tool. It systemizes and customizes each step of mold quotation. After the user decide the number of cavities and choose the suitable moldbase, he can follow the navigating steps to design gates, slides, inserts, and lifters on the CAD model. After the manufacturing processes for each component is decided, the system can calculate the machining time and cost intuitively. Finally, a detailed material and machining quotation report can be generated automatically.
METALLIZER CONDITIONS IMPACT ON LAMINATION BOND STRENGTH OF METALLIZED OPP
Metallized films are used extensively in flexible packaging to supply light moisture and oxygen barrier. Generally the film is laminated to a printed web to protect the metal and to add functionality and product identification information. It is desired that the lamination bond strength be high and uniform. This study shows that metallization conditions have an impact on extrusion lamination bond strengths and highlights the impact of lamination conditions on metal crazing.
METALLIZER CONDITIONS IMPACT ON LAMINATION BOND STRENGTH OF METALLIZED OPP
Metallized films are used extensively in flexible packaging to supply light, moisture and oxygen barrier. Generally the film is laminated to a printed web to protect the metal and to add functionality and product identification information. It is desired that the lamination bond strength be high and uniform. This study shows that metallization conditions have an impact on extrusion lamination bond strengths and highlights the impact of lamination conditions on metal crazing.
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