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.
The SPE Library is just one of the great benefits of being an SPE member! Are you taking advantage of all of your SPE Benefits?
M. Kontopoulou, J.A. Lee, L.C. Huang, W.E. Baker, A.M. Henderson, May 2001
Blends of Ethylene-Vinyl-Acetate copolymers (EVA) with metallocene based ethylene-a-olefin copolymers have been studied, with the purpose of exploring their properties and potential in film packaging applications. The effect of blend composition on rheological properties, heat seal, optical and tensile properties has been examined. It is shown that depending on their composition, these blends can offer a good balance of properties and processability.
A previously proposed model for the densification of powder compacts under isothermal conditions is extended to provide predictions of shrinkage and non-isothermal densification. This model, combined with predictions of bubble dissolution under non-isothermal conditions can provide a complete description of the shrinkage and densification of powder compacts. Model predictions compare favorably with experimental results.
Polymeric electrical insulation failures are due primarily to material composition, design, processing, service conditions or combinations thereof. Time to failure may be immediate, i.e., as manufactured, if specifications are not met. Others may not develop until after many years of service. Since life expectancy of electrical insulation is of the order of 40 years, failure in less time is considered unacceptable. Examples are given of many types of failure and their prevention for power distribution cable and for lower voltage applications.
Over the last five years, we have developed optical technologies for in-line monitoring of extrusion. We review two areas where we have succeeded in uncovering important concepts and phenomena by shedding light on processes that were previously unobservable. In the area of polymer blends, we have made real-time observations of blend microstructure during extrusion. we found conditions by which droplets could align in the vorticity axis. In the area of sharkskin and polyolefin extrusion, we have visualized how polymer process additives act and what causes sharkskin.
All OEMs will continue to outsource some manufacturing. Business machines, telecommunications, consumer and medical industries are following automotive's example. In 1998, companies farmed out 15% of all manufacturing. In 2000, they will outsource more than 40% (Hambrecht and Quist). This paper will describe in detail what is causing this trend and how it is influencing the plastics processing community. Trends will be discussed documented by survey results. Examples of value-added manufacturing companies are also provided.
This study investigates mechanical behavior and reversibility of dynamically vulcanized EPDM / i-PP blends. The composition of these elastomers dictates their morphology, which in turn controls their mechanical behavior. Six compositions are examined under dynamic loading. Dynamic mechanical responses are examined in terms of the Payne effect as a function of composition, cure state, and i-PP molecular weight. The Kraus model is applied and the resulting parameters are explained as a function of morphology.
The density of a rotomolded part can be directly related to several physical properties such as impact, flexural modulus and tensile strength. Depending on the rotomolding conditions, the part will have a range of these physical properties. Part or as is" density can help predict the performance of the final product. This paper will provide the link between the aforementioned physical properties and the rotomolded part density."
Polyethyleneterephthalate (PET) is widely used as a molding material, but increase in its uses has been limited by a tendency of the parts to distort in shape over long periods of time. These changes appear to be due to slow crystallization rate. In order to improve dimensional stability, experiments on the optimum drying condition on the rate of crystallization by adding polypropylene (PP) and TiO2 as nucleating agents and on the melt processing conditions were performed. DSC, WAXD and the Cone and Plate Rheometer were used.
Jim Fogarty, Dave Fogarty, Chris Rauwendaal, Antoine Rios, May 2001
This paper introduces a new screw design concept for foam extrusion developed recently (1, 2). This patented screw design achieves more efficient mixing and heat transfer allowing significant improvements in output rate and product end quality. First the Turbo-Screw geometry will be explained. Second, results from actual foam production operations will be discussed. Third, a 3D numerical analysis of flow in the Turbo-Screw will be described.
A flexible foam material having a high service temperature has been extruded from a blend of a low-density polyethylene resin and a syndiotactic polypropylene resin. Owing to its slow rate of crystallization, a syndiotactic polypropylene resin does not interfere with foam expansion of the polyethylene resin but provides the foam the desired temperature resistance by in-situ crystallization.
The dynamic torque for a 63.5-mm extruder was measured with a Wheatstone strain-gage bridge attached to its single-stage screw between the drive and flow channel. Measurements were made of torque for three resins: (1) LDPE pellets, (2) PET pellets, and (3) PET powder. The results show that the dynamic torque of each resin is unique, and that it depends upon screw speed and on solids' conveying barrel-metal temperature.
The focus of this paper is how creativity and innovation spurred new growth as management learned to fit the organization to the task, mission and culture of the company. Exploring ways leading industry companies are forging into the future with amazing results. This paper will address first, the environment needed to build and sustain creativity and innovation. Second, the methods companies are utilizing to stimulate that creativity and innovation.
John R. Collier, Simioan Petrovan, Bijan Seyfzadeh, Parag Patil, May 2001
Processing of polymer melts and solutions is strongly influenced by both shear and elongational rheology. Molecular weight, molecular weight distribution, degree of branching, branch length and their distribution on the host chain are influential on both. In this work the elongational viscosity and first normal stress coefficient are related to molecular parameters of some polyolefins.
Nylon-6 pellets were compounded with glass fibers in a twin-screw extruder and the resulting pellets were reprocessed for four times through twin-screw extrusion. Collected samples were injection molded and izod impact and tensile tests were performed. Also, fiber length distribution curves were obtained. Results showed that beyond a certain length, fiber attrition is almost stopped and the mechanical properties reach asymptotically low values.
Polybutylene terephthalate was reinforced by 10-40% of short (0.5 mm) and long (10 mm) glass fibers, using a range of process conditions to prepare test samples. Harsher process conditions gave shorter final fiber lengths. Tensile modulus and notched Izod impact strength correlated with glass fiber length and concentration.
Stress-relaxation behavior of various polyolefin films has been studied. It has been proved that the stress-relaxation technique is a more sensitive tool than usual tensile tests when discussing anisotropy in machine and transverse directions. An influence of irradiation dose on the relaxation time spectrum has been demonstrated. The relaxation behavior of three layer composite film has been studied. It was shown that the relaxation behavior of composite film can be predicted if one knows the relaxation time spectrum of each layer.
The world markets for the polyolefins, polyethylene and polypropylene are reviewed. The relative economics of these polymers in the US market are then reviewed to provide a background to assist the reader in forecasting possible future economic trends.
In this study we examine the use of a combination of CO2 and 2-propanol (PrOH), as blowing agents for PMMA foam. Gaseous CO2 was dissolved in liquid PrOH, allowing for injection of a homogenous liquid mixture into the extruder. The advantage of such a system is that the CO2/PrOH ratio remains constant, and the mixture can easily be metered with a suitable pump. The PMMA foamed with this equilibrium mixture was similar to foams prepared with separately injected CO2 and PrOH.
Besides improvements in the optical and mechanical properties as well as carrier-functions for conductive metal layers, the functionality of polymers in electronic applications can be extended through addition of specific fillers. Thereby, the properties of the filled polymer can approach those of the filler, Table 1. Compounding magnetizable fillers into a polymer matrix allows for the rational manufacture of more complex permanent magnets with improved material characteristics by the injection molding process.
Present-day blending technology was developed primarily to forcibly melt and mix polymers and additives. Desired morphologies are often pursued by time consuming iteration. In this study, a new continuous flow blending process is described where morphology develops progressively and more controllably by chaotic mixing. A variety of commercially important blend morphologies, including very highly multilayered blends, are described that have been extruded. The process may serve as a basis for new blending and multilayer film technologies.
84 countries and 60k+ stakeholders strong, SPE unites
professionals worldwide – helping them succeed and strengthening their skills through networking,
events, training, and knowledge sharing.
No matter where you work in the plastics industry value
you're a scientist, engineer,
technical personnel or a senior executive-nor what your background is, education, gender, culture or
age-we are here to serve you.
Our members needs are our passion. We work hard so that we
can ensure that
everyone has the tools necessary to meet her or his personal & professional goals.
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
Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.