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
A Web-Based Knowledge Management System for the Injection Molding Process
L.-S. Turng, D. DeAugistine, May 1999
This paper presents the motivation, development, and system components of a Web-based Knowledge Management System (KMS) for the injection molding process. It also discusses the impact and potential benefits of employing Web technology to manage and share data, information, knowledge*, and analysis results by various parties that are involved in the design and manufacture of injection-molded parts.
Investigation of the Rheological Properties of Rotomolding Resins
Alvin Spence, May 1999
There are many influential factors and processing variables that can impact the mechanical and aesthetic properties of a rotomolded part. One of the main variables is the resin being processed and its associated rheological properties. The manner by which the polymer powder sinters and fuses together needs to be understood to ensure the correct processing cycle is used to obtain an optimum cured part. The influence of bubbles that form during the sintering phase and the melt index of the material, contribute to the quality of the part being produced.
Analysis, Synthesis and Design of Plastics Processing Operations
Guido Bendrich, Rickey Dubay, May 1999
In an attempt to prepare our students better for the challenges after their University study, the Departments of Chemical and Mechanical Engineering at the University of New Brunswick are continuously seeking new ways to expose the students to state-of-the-art real world technologies. The authors present an approach for introducing the students to various aspects of plastics processing and training on an example of their senior design course.
Attending Trade Shows: Maximize the Value, Minimize the Hassle
Debbie Hauser, May 1999
The trade show is a vital component to the plastics industry. As we depend more and more on e-mail, the internet and conference calls, we have become removed from each other. The opportunities to speak face to face, and business to business with so many companies under one roof, is unique to the trade show setting. In this presentation several suggestions and tips" will be discussed which will help you optimize your trade show experience."
Art to Part: A Successful Plastic Product Introduction
Todd D. Cook, May 1999
A thermoplastic rifle stock for a new rifle was developed. Initial wooden models were shaped to meet market demands. CAD models were produced both manually and using digitizing with little difference in outcome. CAD models should include manufacturing process related geometry issues such as draft allowance and gate vestige size and location. Examples of methods to prevent problems are outlined throughout the development process. Ultimately, a successful new product was delivered to the marketplace with both prototype and production tooling.
A New Hypothesis to Describe the Acting Mechanisms in a Welded Joint of Semi-Crystalline Thermoplastics
Ch. Bonten, May 1999
Since it is known that cross-linked Polyethylene can be welded, it is clear that the acting mechanisms in the interior of a welded joint are not adequately explained yet. There are several criterion, hypotheses and models that try to describe what happens in a welded joint. In this paper two new promising hypotheses, the Mixed Crystal Hypothesis and the Nexus Hypothesis, are introduced. The Mixed Crystal Hypothesis can be proven by the help of several different examination methods. Other examinations support the Nexus Hypothesis.
Computer Simulation of Plastics Compounding Operations in Twin-Screw Extruders
Eduardo L. Canedo, May 1999
This presentation is concerned with the development of process simulators for the analysis of compounding operations in modular corotating intermeshing twin-screw extruders. Approximate flow and heat transfer models are presented and implemented in a personal computer based software package for the fast simulation of the processing behavior in realistic settings.
Microlayer Coextrusion Technology
E. Baer, D. Jarus, A. Hiltner, May 1999
Coextrusion with three or more layers is commonly used to produce end products that have properties with a good mix of the individual components. Layer multiplying technology allows for coextruded samples to be multiplied into tens or even thousands of layers, producing microlayers. In this manner, a wide variety of polymers can be combined intimately with minimal mixing. Microlayers have several distinct advantages as both a research tool and as a method of producing end products with enhanced properties. The effect of large interfacial area and of scaling is discussed with several example systems.
Rapid Adhesives Bonding: Kinetic or Process Control?
George W. Ritter, May 1999
Adhesive bonding typically produces slow strength build. Accelerating processes are used to heat the adhesive rapidly. Two approaches are used: heat the adherends, which transfers heat to the adhesive, or heat the adhesive directly using added susceptor material. In this paper, the relative merits of both approaches are examined using induction and microwave heating as examples. Each approach is discussed along with the importance of curing kinetics at temperature.
A Melting Rate Model Based on Extrusion Data
Stephen J. Derezinski, May 1999
To design an extruder screw for a given polymer, the barrel length for melting is needed for a given flow rate and speed. The melting rate needed for calculating the length is given through the conservation laws in cylindrical coordinates based on defined fundamental average parameters. Extrusion machine data are used to calculate the functions of the parameters. Results based on polyethylene data are given.
Study of the CaCO3 Filled PP/HDPE Composites Using Different Surface Modifiers
M.N. Ichazo, J. González, C. Albano, B. Díaz, May 1999
This article describes the surface modification of CaCO3 filler with three titanate and one zirconate coupling agents and its effects on the properties of the PP/HDPE blends. CaCO3 was coated with these coupling agents of varying concentration (0.3-1 wt. %). The best performance in terms of tensile modulus was observed in blends having 0.7% titanate coupling agent (LICA 12). SEM microgrhaps indicated better dispersion and decreased agglomeration of the smaller CaCO3 particles.
Effect of the Filler Size and Composition on the Properties of Injection Molded PP and PP/HDPE-Wood Flour Composites
C. Albano, M.N. Ichazo, J. González, K. Molina, L. Espejo, May 1999
The effect of the filler size and composition on the mechanical properties of wood flour-PP composites was studied. The blends were prepared in an intermeshing co-rotating twin screw extruder and injection molded. The best properties (elastic modulus and tensile strength) were obtained for the 40 wt. % wood flour composites for all filler sizes employed. PP/HDPE blends (80/20 wt. %) were prepared based on the higher wood flour content of the composites tested previously.
Mixing Performance of Twin Screw Extruders during Melt-Melt Blending
Gifford Shearer, Costas Tzoganakis, May 1999
The mixing performance of a co-rotating twin screw extruder during melt-melt blending of polypropylene was experimentally investigated using an interfacial reaction between reactive polymer tracers. The conversion was dependent on the formation of interfacial area between the two melt streams, and therefore, the distributive mixing performance was directly measured using this technique. The focus of the experiments was to determine the effects of machine parameters (screw design and operating conditions) on the mixing performance.
Extrusion of LLDPE through Polypropylene Coated Dies
Gifford Shearer, Costas Tzoganakis, May 1999
Polypropylene (PP) coated dies were used in an attempt to decrease the die pressure and eliminate surface melt fracture during the extrusion of linear low density polyethylene (LLDPE). The investigated coatings were: controlled-rheology PP, hydrosilylated PP, amorphous PP wax, and maleic anhydride grafted PP. Extrusion stability, die pressure, and extrudate appearance were used to compare the effectiveness of the different coatings.
ISO/QS Process Certification: Measuring the Proper Variables
Bill Fierens, Dan Fisher, Mark Shade, John Bozzelli, May 1999
The trend in the injection molding industry today is to measure and record machine specific process variables. The goal of this paper is to explain the concept behind measuring and recording process conditions rather than equipment setpoints. The purpose of doing so, will be to convince molders everywhere that a non-machine specific process sheet will enable the processor to produce identical parts from machine to machine. The benefits are numerous, especially when one considers ISO and QS certification and the financial investment that they bring.
New Olefin Polymerization and Copolymerization Catalysts
Ayusman Sen, May 1999
Two transition metal-based catalytic systems for the homo and copolymerization of olefins will be discussed. The first encompasses palladium(II)-catalyzed alternating copolymerization of olefins with carbon monoxide. The polymers synthesized include chiral isotactic copolymers derived from both simple olefins, as well as those bearing a variety of functional groups. The second system involves palladium(II) catalyzed homopolymerization of norbornene derivatives and their copolymerization with acrylates.
Prediction of Viscoelastic Behaviour of Thermorheologically Complex Polymeric Materials
Naba K. Dutta, N. Roy Choudhury, Janis Matisons, G.H. Edward, May 1999
A simplified numerical computational technique based on a Gaussian spectral distribution model developed by Dutta and Edward [1] has been used to describe the stress relaxation behavior of polystyrene (PS) and isotactic polypropylene (iPP) over a wide range of, time and temperature. An excellent fit between experimental data and the mathematical model is observed. The method may be applied generally for any linear viscoelastic property and for any polymer.
Dynamic Mechanical Analyzer, DMA, as an Equipment to Determine Sonic Damping of Plastic Materials
Russell R. Ulbrich, Parviz Baghaii, May 1999
A Dynamic Mechanical Thermal Analyzer, DMTA, instrument can be used to study noise reduction of thermoplastic composites. In this study, a polyamide 66 matrix modified with impact modifier, impact modifier plus foaming agent, and 30% glass fibers have been studied. In this study, the addition of impact modifier enhances the noise damping of the composite material by a factor of two.
Fracture Mechanics of a Shaft-Loaded Blister Delamination - Transition from a Bending Plate to a Stretching Membrane
Kai-tak Wan, Kin Liao, May 1999
Mechanical Properties and adhesion strength of a thin polymer coating on a rigid substrate can be measured directly by two tests: (i) a one-dimensional V-peel (pull-off experiment); (ii) a central point load (shaft-loaded blister). In either case, it is found that G = ? (Fw0 / A) with ? a numerical constant depending on the ratio of bending to stretching stresses on the film. It is shown that delamination behavior depends strongly on the film thickness and the extent of deformation.
Measuring Mechanical Properties of Thin Films by a Hemispherical Capped Shaft-Loaded Blister Test
Kai-tak Wan, John Xiong, Kin Liao, May 1999
A new shaft-loaded blister test is used to directly measure the mechanical properties of thin polymeric films. The shaft tip is rounded to a hemispherical cap to avoid film puncture. An elastic solution is suggested for the applied load as a function of shaft displacement, which depends on the ratio of shaft radius to blister dimension. To avoid concentrated load, an alternative way of loading the blister is by a horizontal cylinder of finite radius.
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