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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Extrusion Process and Screw Design Investigation via Experiment Design and Computer Simulation
This paper explores the value of Design of Experiments (DOE) statistical analytical techniques and mathematical modeling of extruder behavior to characterize extrusion performance.
Improved Dispersion of Yellow Metal Azo Pigment in Polyethylene Film
Pigment Yellow 62 (PY62) is widely used in the extruded polyethylene film industry. Increasing demands for throughput, quality and reduced wastage led to the need for a new grade of PY62.Research showed that control of PY62 particle size and dispersion directly affected properties such as film transparency, colour development, extruder pressure build and processing time. Using this knowledge a new PY 62 for polyethylene film was developed and successfully tested.
A Review of Melting Mechanisms in Single Screw Extrusion
This paper will present a review of basic melting mechanisms and the assumptions on which melting models are based. In addition a discussion of the impact of checking models with extruder model calculations vs. direct melting measurement (screw simulator). A discussion of the low screw speed mechanisms" seen lately and discuss the impact of measuring techniques controlling observations vs. the observations controlling the measurement techniques"
Observations on Field Fusion Joining of Large Diameter HDPE Pipe
Large diameter high density polyethylene (HDPE) pipe has been utilized for various municipal and industrial applications for over 30 years. Butt fusion procedures developed in the earliest days of polyethylene pipe fusion are still the ones recommended for joining this pipe in the field. Analysis of recent problems with pipe fused in the field suggests that modern workers are trying to speed up the joining process by not adhering to all of the recommended procedures. These problems will be examined in detail and the implications of short cuts in the procedure discussed.
Effects of Process Conditions on Shrinkage of the Injection-Molded Part
Shrinkage behavior plays a critical role in determining the final shape and dimensions of an injection-molded part. In this paper, the CAE and Taguchi DOE technique were combined to investigate the influence of factors on the shrinkage behavior of the injection molded part and optimize the process conditions, the part quality was improved under the optimum process conditions obviously.
Problem Solving by Thermal Analysis in the Automotive Plastic Industry
Thermal analysis studies the thermo physical and thermo chemical properties of a material. In a series of case studies, various thermal analyses, such as DSC, TGA, TGMS, DMA, and TMA were used to solve real life problems in the automotive plastic industry.
Two Solutions for Three-Dimensional Flow Simulation of Injection Molding
This work presents two methods: Dual Domain and Real 3D to simulate the flow on the solid model from CAD. Dual Domain assumes the melt flow along the dual surfaces and employs hot runners to connect the coupled nodes to keep the melt flowing uniform on the surfaces. Real 3D employs an iterative method to solve coupled pressure and velocity independently. It reduces memory needs in simulation and enhances the stability of numerical scheme. Experiments indict they are valid for certain parts.
Selecting the Right Decorating Method - Pad Printing vs. Screen Printing vs. Hot Stamping
This article will help to explain the various aspects, including strengths and weakness’ of the three primary decorating technologies that are widely utilized in the plastics molding/ decorating industry, namely; Pad Printing, Screen Printing and Hot Stamping technologies. While each technology has its place and area of competence, it is important to note that not one of these technologies is perfect for all decorating applications. So with that in mind, you may end up needing to invest in more that one or all of these useful decorating technologies.
The Systemic Analysis of Metal Injection Moulding
The study carried out comprises the making and description of the general model for metal injection moulding and the analysis of mentioned process with Ropohl’s theoretical definitions. The model includes a complex of elements of metal injection technology, the elements being the core of the model, and the inputs, outputs and relations between the above-mentioned elements. The basic principles of this technology and all the phenomena connected with MIM are represented by means of inputs, outputs and relations. An exact analysis of metal injection moulding was made by a precise and systematic approach.
Case Studies of Plastics Failure Related to Molecular Weight or Chemical Composition
Processability and product performance depend on having the appropriate polymer molecular weight and composition of the formulation. Failures were caused by errors of molecular weight or composition. GPC played a key role in molecular weight cases. IR spectroscopy and GC/MS were used for composition.
Mechanical Property Optimization of Polypropylene Based Blends Using a Continuous Chaotic Advection Blender
A continuous chaotic advection blender was used to controllably develop in extrusions a variety of morphologies in PP/EPDM and PP/LDPE blends. Impact toughness was enhanced by 760% with the addition of 20% EPDM by a blend consisting of numerous interconnected layers. Smaller but significant improvements to impact properties were also obtained for PP-LDPE blends. Enhancements were greater than those derived from droplet morphologies typically obtained with conventional compounding equipment.
Influence of Shear on Immiscible Polymer Blend Morphology Development by Chaotic Advection
In recent years, a wide variety of morphologies in immiscible blends at fixed compositions have been formed in chaotic advection blending devices. To clarify how particular morphologies arise, computational simulations have been performed and compared to findings with a continuous chaotic advection blender. Simulations are in good qualitative agreement with experiments. Hole formation and melt redistribution among layers and shear during processing interact to give blends with dual continuous phases, fibers, and droplets and other morphologies.
Novel Clay Nanocompositeswith Platelets Oriented by Chaotic Advection
A continuous chaotic advection blender (CCAB) has been used to orient clay platelets prior to extrusion steps. Methods allow extrusion of nanocomposites with oriented platelets so clay loading can be reduced and properties can be enhanced. Extrusions can be of a variety of forms such that profile parts or high barrier films can be produced. Micrographs of the nanocomposites are presented and related to processing conditions.
A Method of Quantifying Program and Course Performances against ABET Criteria
This paper describes a spreadsheet based method that quantifies the performance of an educational program and its various courses against the ABET criteria. Inputs to the spreadsheet are: student learning outcomes for each course, cross index tabulation of these outcomes to ABET criteria, student scores, and credit hours of courses. This approach identifies the strong and weak points of each course as well as the whole program. This method becomes an integral part of a continuous improvement plan.
Design and Optimisation of a Standard Milk Crate Using FEM
This paper presents an investigation on the design and optimization of plastic milk crates using the finite element method (FEM) with the aim of reducing the mass and simplifying the shape of a standard milk crate. The paper also explores the possibility of manufacturing such milk crates using recycled High Density Polyethylene (HDPE) instead of virgin HDPE or virgin polypropylene (PP) to make it more cost effective.
Clay Exfoliation and Content Effect on Nylon Nanocomposite Foams
Amorphous nylon 6 nanocomposites with various clay contents and dispersion degrees were prepared by direct twin-screw extruder compounding. The nanocomposite structures were examined with XRD and TEM. The effects of clay exfoliation and content on microcellular extrusion foaming of amorphous nylon 6 nanocomposites will be presented. Apart from their nucleating role in bubble nucleation, nanoclay particles also promoted the volume expansion ratio of nylon foams. The role of clay particles on diffusivity will be discussed critically.
Domain Decomposition for 3D Flow Simulation of Injection Molding
This work generalizes D-N and Schwarz schemes for elliptic equation to Stokes and injection molding problem and constructs the non-overlapping and overlapping sub problem. It divides the original problem into several sub problems and distributes them to different processor to solve simutaneously. This method can accelerate the 3-D flow simulation involving large scale calculation.
Wall Thickness Optimization in Molded Product Design
Wall thickness is a vital design decision that affects structural performance, material utilization, and processing costs. Simple flow and bending analyses are developed and validated against sophisticated 3D finite element analyses for use in early product development. The simple analysis indicates the desirability of 1) simultaneous wall thickness and rib design, and 2) adding ribs to the design to increase stiffness as needed. Finally, calculus is applied to solve for optimal flow length to wall thickness ratio as a function of material costs and machine rates.
Design of an Instrumented Mold to Verify Air Gap Formation during Cooling in Box-Shaped Parts
Shrinkage occurs asymmetrically during the cooling stage of an injection molding cycle. When this happens, especially in box and cup shaped injection molded parts, an air gap forms, drastically reducing heat transfer rates into the cavity steel. In order to verify the gaps existence and volumetric size, an injection mold is modified with componentry to quantify the separation from cavity steel.
Heat Transfer Study of Air Gap Influence on Cooling in Boxshaped Parts
Air gap influence on cooling in cup shaped parts is an undocumented phenomenon, requiring additional analysis and quantitative measurement. As an enhancement to a previous investigation, the heat transfer behavior of a plastic part is analyzed by using a finite-element model that incorporates shrinkage, and resulting gap, from PVT estimates. The heat loss of a part without an air gap and one with an air gap are contrasted to determine the significance of the air gap on cooling.
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