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 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.
B. Seyfzadeh, D.A. Zumbrunnen, R.A. Ross, May 2001
An engineering model was developed to predict the debris particle deposition of a non-Newtonian melt in an extrusion filter medium. The model is based on mass conservation in a three-dimensional finite volume space in conjunction with a power law modified Darcy's equation for porous media flows. Validation was performed by comparison to start-up pressure drops across filter media employed in fiber spinning. Parametric studies revealed the influence on debris deposition of various filter housing contours and power law indices.
A technique is described that enhances the ASTM D5397 Constant Tensile Load (CTL) test by replacing the standard type L" dogbone specimen with a Compact-Tension (CT) specimen. By measuring the center-line crack opening displacement (COD) of the CT specimen while stressed under a test solution one can describe crack growth properties in terms of a stress intensity factor (K) and estimate a corresponding crack growth rate."
For the task of designing cooling parts of a cable coating line, it is very helpful to use modeling of the temperature behavior of the product in cooling line. This presentation shows two models, which can be used for numerical simulations. Authors also deal with the question, if the heat flux in direction of the movement is negligible. The comparison of results of simulated cases and measurement on real coated cables is shown.
Paul Elkouss, Rajath Mudalamane, Yue Huang, Keita Broadwater, David Bigio, May 2001
The effect of operating and feeding conditions on the impact modification of Nylon 6,6 with Poly-Olefin Rubber Impact Modifier (POIM) were studied. The results indicated that the notched izod values are uniformly higher for the samples with POIM fed separately downstream than those of the preblended samples. The notched izod values also show a slight correlation to the throughput, Q. The existence of a critical interparticle distance was verified by image analysis.
As melt flows from the barrel of a capillary rheometer into a die the streamlines converge, producing a strong extensional flow. The entrance pressure loss is determined with orifice die and Bagley correction. The failure of the measurement with orifice die like outlet angle and length of the die is evaluated and extensional viscosity is calculated using the theory of Cogswell. The results of extensional viscosity will be compared with Rheotens elongation data.
The current system of injecting hot polymer into a comparatively cold mold results in the development of a solidified layer and reduction in part quality. As a consequence of this process limitation, molding systems continue to produce inferior components during production. This paper develops an innovative mold design and preheating process to dynamically control the temperature at the mold-polymer interface during the molding cycle. Simulation indicates that a preheat system can significantly reduce residual stress compared to conventional molding given equivalent cycle times.
Kim McLoughlin Senior Research Engineer, Global Materials Science Braskem
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Kim drives technology programs at Braskem to develop advanced polyolefins with improved recyclability and sustainability. As Principal Investigator on a REMADE-funded collaboration, Kim leads a diverse industry-academic team that is developing a process to recycle elastomers as secondary feedstock. Kim has a PhD in Chemical Engineering from Cornell. She is an inventor on more than 25 patents and applications for novel polyolefin technologies. Kim is on the Board of Directors of SPE’s Thermoplastic Materials & Foams Division, where she has served as Education Chair and Councilor.
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Gamini has a BS and PhD from Purdue University in Materials Engineering and Sustainability. He joined Penn State as a Post Doctorate Scholar in 2020 prior to his professorship appointment. He works closely with PA plastics manufacturers to implement sustainability programs in their plants.
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Tom Giovannetti holds a Degree in Mechanical Engineering from The University of Tulsa and for the last 26 years has worked for Chevron Phillips Chemical Company. Tom started his plastics career by designing various injection molded products for the chemical industry including explosion proof plugs and receptacles, panel boards and detonation arrestors for 24 inch pipelines. Tom also holds a patent for design of a polyphenylene sulfide sleeve in a nylon coolant cross-over of an air intake manifold and is a Certified Plastic Technologist through the Society of Plastic Engineers. Tom serves on the Oklahoma Section Board as Councilor, is also the past president of the local Oklahoma SPE Section, and as well serves on the SPE Injection Molding Division board.
Joseph Lawrence, Ph.D. Senior Director and Research Professor University of Toledo
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Dr. Joseph Lawrence is a Research Professor and Senior Director of the Polymer Institute and the Center for Materials and Sensor Characterization at the University of Toledo. He is a Chemical Engineer by training and after working in the process industry, he has been engaged in polymers and composites research for 18+ years. In the Polymer Institute he leads research on renewably sourced polymers, plastics recycling, and additive manufacturing. He is also the lead investigator of the Polyesters and Barrier Materials Research Consortium funded by industry. Dr. Lawrence has advised 20 graduate students, mentored 8 staff scientists and several undergraduate students. He is a peer reviewer in several journals, has authored 30+ peer-reviewed publications and serves on the board of the Injection Molding Division of SPE.
Matt Hammernik Northeast Account Manager Hasco America
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Matt Hammernik serves as Hasco America’s Northeast Area Account Manager covering the states Michigan, Ohio, Indiana, and Kentucky. He started with Hasco America at the beginning of March 2022. Matt started in the Injection Mold Industry roughly 10 years ago as an estimator quoting injection mold base steel, components and machining. He advanced into outside sales and has been serving molders, mold builders and mold makers for about 7 years.
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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, ISBN: 123-0-1234567-8-9, pp. 000-000.
Available: www.4spe.org.
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.