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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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The supply chain for polymeric materials is a drastically changing environment. This paper will focus on the types of trade names used. Changes of ownership along with historic trade names will be discussed. Predictions of future uses and types of trade names will be made.
The condition for the breakup, of a power-law non-Newtonian slender drop in a Newtonian liquid in an axisymmetric extensional flow, has been theoretically studied. The problem is governed by four dimensionless numbers: The capillary number, the Reynolds number, the viscosity ratio and the power-law index. The results suggest that the critical capillary number for drop breakup increases as the Reynolds number, the viscosity ratio and the power-law index decrease.
In this work the rheological properties of polymer have been studied by molecular dynamics simulation. Couette flow with various shear rates are used to investigate the degree of slip, shear viscosity and normal stress difference. The fluid consists of chains of n-hexadecane and is confined between two structured gold atomic walls. Isothermal simulations (350K) of 4 to 1 unsteady extrusion flow with various extrusion rates are conducted.
Geometry of a flat die for polymer sheet extrusion is optimized to obtain a uniform velocity distribution across the exit of the die. While optimizing the exit velocity distribution, the constraint optimization algorithm used in this work enforced a limit on the maximum allowable pressure drop in the die. Effect of the shear as well as elongational viscosity of the polymer on the flow in the flat die is taken into account.
A range of unplasticised polyvinylchloride (uPVC) profile extrusion grade formulations, containing calcium/zinc, organotin and lead based stabiliser systems were blended with different concentrations of TiO2. Rheological analysis showed that the concentration of TiO2 (2phr - 8phr) had little effect on viscosity over the shear rate (200-1000s-1) and temperature range (170 – 190°C) studied. Mechanical analysis showed higher tensile and flexural modulii for the organotin stabilised formulations.
Resins used in profile extrusion require high viscosity at low shear rates to improve melt strength and low viscosity at high shear rates to prevent melt fracture. This paper discusses the development of copolyester resins with the desirable rheological properties, as well as good optical and physical properties. The processing, biocompatibility, and sterilization of these resins will also be discussed.
Postulating that arterial injury resulting from the angioplasty intervention is a possible predictor of restenosis, a three-dimensional finite element model is proposed to predict stresses during balloon angioplasty. The model simulates balloon folding, insertion and deployment into a diseased artery. This work focuses on the balloon material model and properties, using experimental characterization and inverse modelling. A numerical example, including balloon folding and deployment inside a stenosed artery is also presented.
The small punch test is a useful technique in the mechanical testing of polymers where limited material is available. This investigation focuses on the latest developments in the small punch test design, including integrated temperature control and environmental conditioning and its use in analysis of polymethyl methacrylate (PMMA) bone cement.
It has never been easy, in the Medical Products Industry to design and build a custom plastic enclosure when the initial or lifetime quantities do not justify molds or tooling. In the last few years, a toolless technology has been commercialized to allow the manufacture of such enclosures, with minimal up front costs and broad design flexibility. This paper describes the technology, its application, strengths and limitations and provides an economic comparison to the other enclosure technologies used in the industry.
Barium sulphate (BaSO4) is widely used as a radiopaque additive for medical grade PVC tubing in surgical procedures. The rheological characteristics and mechanical performance of two different medical grade PVCs containing BaSO4 (10-15 % w/w) having two different mean particle sizes (1 and 40 micron) was investigated. The results show significant change in melt viscosity, tensile properties and phase transitions (Tan ? max) with increase in BaSO4 concentration.
The effect of epoxy/hydrogen-amine ratio and thermoplastic molecular weight on the curing process and final morphology of epoxy thermoset-polysulfone blend is presented. The cure kinetics was followed by differential scanning calorimetry, the beginning of phase separation by was determined by visual inspection and final morphology was analyzed by SEM.
Using a 3 mm thick mold trying to reproduce common industrial situations, a general purpose UPR was cured with styrene, methyl ethyl ketone peroxide (MEKP) and cobalt naphthenate. Modelling of the curing reaction (using a 2k with 5 central points design), tensile and impact strength and glass transition temperature was accomplished. To obtain close fitting, parameters interaction was considered for modelling.
Plastics injection molding has been limited by the lack of observability and controllability, such that it has not been possible to know or control flow rates and pressures at multiple locations in a mold. An instrumentation and analysis method is presented that allows the estimation of flow rate and pressure at multiple points in an injection mold. While potential improvements are discussed, the presented methods will assist real time process and quality control.
Novel high flow, low crystallinity polyolefin polymers offer a wide variety of attributes in a broad range of applications. The basic characteristics of these polymers and their usefulness in applications such as hot melt adhesives, flow modification, masterbatches and color concentrates, thermoplastic polyolefins (TPOs), and thermoplastic road markings will be discussed.
This paper reviews the research over the past number of years on diffusion of fuels and fuel components into polymers used in near engine fluid and fuel delivery systems. The areas investigated cover Fourier Transform Infra-Red (FTIR-ATR) spectrometry and standard immersion procedures to measure the migration of fuel components in a series of fluoropolymer, polyester and polyamide materials at various temperatures.
General Motors’ next generation full-size truck frames are currently 80 pounds over their targeted weight. By replacing the current steel transmission cross member on General Motors’ full-size trucks through the application of a composite material transmission cross member, a substantial weight reduction will be achieved. Reducing the weight of General Motors’ full-size trucks will consequently increase the fleet-wide fuel economy for the company’s truck line, allowing CAFE requirements to be met more easily.
The enhancement of one particular performance parameter in a Thermoplastic Polyolefin (TPO) is often tied to a decrease in another property. This trade-off is evident in the balance between compound viscosity and impact performance. While low melt index elastomers will result in higher impact performance, the increase in compound viscosity is undesired. This paper discloses the utility of adding ultra-low viscosity modifiers to a TPO to achieve high flow while retaining impact performance.
Computer aided engineering has impacted the design process of weatherseal systems by reducing the number of prototypes needed to create a part. Finite Element Analysis is useful in predicting compression load deflection and frictional forces. Advances in FEA include how forces change over time and loading; stress relaxation, cyclic loading, compression set, and elastic recovery. This paper follows the design and prototyping of a unique weatherseal system and highlights the role of CAE.
This paper examines material and design trends in exterior automotive plastic applications. Plastics are widely used in exterior automotive applications. With the many different exterior applications, this paper concentrates specifically on fascia, body side moldings/ claddings, rocker moldings, wheel flare, and cowl vent leaf catchers. Examination of the material and design trends for these exterior applications is accomplished by benchmarking a number of OEMs. Insight into future material and design trends is gained by identifying the drivers.
In this work, an extrusion process has been developed for the devulcanization of rubber crumb from recycled tires employing supercritical CO2. For that purpose supercritical CO2 has been injected in a twin screw extruder to swell the rubber crumb and to facilitate the otherwise impossible rubber extrusion process. As a consequence, waste rubber can be processed under mechanical shear and extensional forces at various operating conditions that may lead to different degrees of devulcanization.
Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
Brown, H. L. and Jones, D. H. 2016, May.
"Insert title of paper here in quotes,"
ANTEC 2016 - Indianapolis, Indiana, USA May 23-25, 2016. [On-line].
Society of Plastics Engineers
Available: www.4spe.org.
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