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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Molecular Analysis of Polymers by FTIR Photoacoustic Spectroscopy
FTIR Photoacoustic Spectroscopy (PAS) has advantages relative to conventional infrared techniques (transmission, reflection, and emission) because it is non-destructive, does not involve sample preparation, and can probe samples with compositional gradients and layers. The theory, instrumentation, methods, and applications of FTIR-PAS are discussed and results are presented on several polymer analyses based on FTIR-PAS.
Study of PVC/Grafted Polyethylene Blends
Two commercial types of polyvinyl chloride with different K values were blended with LLDPE, HDPE, LDPE, and their grafted products with diethylmaleate. The PVC/PE blends were prepared in two proportions. The blends made with the grafted LLDPE showed to be more translucent than those prepared with non-functionalized LLDPE, due to a much better interfusion between the particles for the first ones. However, the mechanical properties are lower than those of pure PVC.
Product Design with High Value Recyclable Plastic Waste Streams
As part of on-going studies on the manufacturing of re-engineered materials from waste plastic streams, rheological, mechanical and thermal characterization of recyclable plastics from old computer housings and used carpet materials were carried out, with anticipated use in thin-walled products. A combined stress and mold cavity flow analysis has been used to obtain optimum design and process parameters for the anticipated products.
Case Study for Multi-Shot
The objective of this paper is to demonstrate different manufacturing methods to produce the same or a very similar Multi-Shot part. It will conclude by giving cost breakdowns on all options, including capital cost, cycle time and ultimately piece part cost.
A Web-Based Knowledge Management System for the Injection Molding Process
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.
A Knowledge-Based System with Fuzzy Logic for the Tuning of Injection Moulding Machines
The proposed system aims at a) helping injection moulders to tune the process parameters of an injection moulding machine, b) storing knowledge and experience that can be used later and c) creating an integrated tool with information on materials, process parameters so it etc. The system is based on general guidelines coupled together with expert rules from the users and a fuzzy logic system which is responsible for the intelligent communication with the users. Results show the way the system operates in an industrial environment.
Investigation of the Rheological Properties of Rotomolding Resins
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
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
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
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
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
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
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?
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
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
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
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.
Measuring Depolymerization Kinetics of a Methacrylate Using a Novel Optical Technique
A new and inexpensive analytical tool, thermovolumetric analysis (TVA) is similar to thermogravimeti-ic analysis (TGA) except that it is volume rather than mass which is being monitored. This is a new application of laser interferometry which is especially applicable to thin films of polymers which depolymerize at elevated temperatures. Coatings 300 to 1500 nm thick of poly(n-butyl methacrylate) on silicon are removed in an orderly manner when heated at temperatures up to 300°C. The technique can also be employed with the temperature increasing at a constant rate.
Future Overlays for Composite Bridges
The smooth surface of a composite bridge deck pose a significant problem for bonding of an overlay surface. Previous research conducted using cementitious overlays have shown significant delaminations of the overlay when subjected to flexural loading. Epoxy overlays possess superior bonding and other mechanical characteristics, and have been successfully used on concrete-filled steel grid and steel orthotropic decks. Besides, they reduce the overall dead load on the structure due to its thin application. This work presents a brief overview of the properties and future potential of epoxy overlays for composite bridge decks.
Mixing Performance of Twin Screw Extruders during Melt-Melt Blending
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.
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