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.
|= Members Only|
Peelable - Resealable Films: FTIR Characterisation and Peel Strength
In the last decade, smart packaging has been an emerging field, which focuses on improving safety, ease of use and sustainability of food products. In this paper, enhancement in the ease of use is sought through the tailoring of a novel peelable-resealable structure. Therefore, multiple pressure sensitive adhesive (PSA) resins were first screened through by measurement of their peel strength. In light of the Fourier transform infrared spectrums, key properties of the peelable-resealable structure are discussed and material properties correlated to peel strength behavior.
Preparation and Rheological Properties of Epoxy-Based Liquids with Adjustable Viscosities
Epoxy-based liquids with adjustable viscosities were prepared by curing a two-component resin mixture at variable mixing ratios and their rheological properties were then characterized using a parallel plate rheometer. The viscosity was found to decrease as the portion of amine compound component decreased. Moreover, the rheological properties of such liquids were found to be highly thermally sensitive. At last, the authors proposed a possible mechanism to explain the viscosity change at different resin mixing ratios.
The Effect of Multilayer Rheology on the Flow Distribution in a Coathanger Style Die
Multilayer coextrusion is a process in which two or more polymers are extruded and joined together in a feedblock or die to form a single structure with multiple layers. This paper will discuss the effect of experimentally measured multilayer rheology on the flow distribution in a coathanger style die.
Measurement of Transmittance and Reflectance Spectra of Edge-Lit 2-D Polymeric Light Guides
A commercially emerging type of lighting technology utilizing two-dimensional edge-lit polymeric light guide panels is described. Potential polymer-related engineering problems associated with these light fixtures are identified. One of these problems is the possibility of a color differences between panel surface regions close to and far from the light source. The theory and practice of a spectrophotometric method that can be used to assist material selection to solve this problem are described. Illustrative results are shown.
Continuous Devulcanization of Scrap EPDM Rubber with Supercritical CO2: Effect of Process Parameters on Devulcanized Rubber Properties
Scrap EPDM rubber crumb was continuously devulcanized using supercritical CO2 in an industrial-scale twin screw extruder. A reasonably high throughput extrusion process has been developed and the effect of processing conditions has been studied. A central composite design with two factors was used to study the effects of screw speed and feed rate on the sol and gel fractions, degree of devulcanization, and Mooney viscosity of devulcanized rubber.
Control of Heat Conduction Processes for the Improvement of Part Properties in the Two-Stage GITBlow Process
The GITBlow process, a combination of gas-assisted injection molding (“GIT”) and blow molding (“Blow”), allows the production of parts with complex functional geometries and thin-walled hollow spaces directly inside the mold. Part properties can be controlled by selective construction of characteristic part elements and modern methods for cooling control in the mold. Small variations of part geometry or of mold temperatures already show a positive influence on the resulting wall thickness distribution.
Foam Extrusion with Physical Blowing Agents – Engineering Approach
This paper introduces a new Engineering approach to improve and develop the manufacturing process of XPS Polystyrene form. The success in this process will trickle down to other foam processes to improve the productivity and energy savings.
Reliable Hot Tack Testing of Polyolefin Films
Measuring the strength of a seal while it is still in the semi-molten state is important in determining if a film is suitable to withstand high loads at high packaging speeds. Without high hot tack strength, the contents of the package may break through the seal during the filling process. In this report, we will utilize Six Sigma methodology to: compare two different separation force hot tack testing machines, identify key variables in testing, and develop a set of standard testing conditions.
Prediction of Powder Concentration for Filling Simulation of Metal Injection Molding
A full 3D finite volume analysis system has been developed to simulate a Metal Injection Molding (MIM) filling process. In the MIM industry, the so-called black lines are frequently observed in the surface inspection of the final sintering products. Such a critical appearance defect is attributed to powder-binder phase separation. Powder concentration is used as an indicator for phase separation. In this work, it is necessary to numerically predict the powder concentration distribution during mold filling and discuss the phase separation issue.
New Color & Effect Pigments and Trends for Plastics
This paper will review the newest color and effect pigments that have been recently introduced to the marketplace including features benefits and comparisons to traditional products that have been used in the past few years. The paper will also review color trends for teletronics, aviation, sporting goods and toys for 2010.
Developing Cost Effective Co-Extruded Film Structures for Flexible Packaging
Co-extrusion enables the combination of attributes of different polymeric resins to create films having unique and tailor-made properties. In this study we show that the proper selection and the correct placement of different polyethylene resins in co-extruded structures enables one to produce films having improved toughness and optical properties in a cost effective way. It was concluded that using single-site linear low density polyethylene in film structures makes this possible.
Rapid Heat Cycle Molding, Surface Topography and Visual Appearance of Injection Molded Parts. Research Work in Leoben in the Last 10 Years.
Different aspects on surface quality of injection molded parts have been researched in Leoben in the last decade. This paper will give a short overview on our research work, considering rapid heat cycle molding, surface topography and visual appearance of polymer part surfaces with special focus on weld lines, sink marks, and gloss differences, respectively.
Using One-Sided Constraints to Improve Prediction of Core Shift during Mold Filling Simulation
Uneven distribution of melt flow around a core pin during injection molding can result in core shift. Many real life injection molds establish one-side constraints for the cores then the core is free to deform in one direction but cannot deform in the opposite direction. In the article we present algorithms and results of mold filling simulations that take into account one-sided constraints on deformation of the mold cores.
A Comparison of the Residence Time in Micro-Extruders and its Effect on Molecular Weight for Low Output Applications
This study investigates the residence time in micro extruders for low output applications. The micro extruders that were analyzed included extruder diameters between 12mm and 25.4mm. This study will show the effect of extruder screw speed on the residence time and compare that to theoretical calculations. Additionally, the study also demonstrates the change in molecular weight for a fixed output rate on the different extruder diameters.
The Role of Pigmentation in the Reduction of Heat Buildup in Polymeric Materials
The accumulation of thermal energy in polymeric materials can pose a serious threat to service life as well as appearance of a finished product. The types and levels of pigments used in the fabrication of polymeric goods can have a profound effect on the impacts of thermal energy accumulation. In this paper we will provide a primer on the physics behind the effects of the terrestrial components of solar radiation and the ways in which different materials behave under typical terrestrial conditions.
Light Cure Adhesive Best Practices/Technical Overview
While light curing technology provides many benefits to manufacturers, careful product selection and planning are needed to assure a smooth change over from existing, slower curing processes. Manufacturers must carefully weigh a variety of process variables to assure a smooth transition from older adhesive technologies when setting up a new light curing process like choosing the light source, understanding the substrates, opacity of materials, implementing process monitoring, adhesive selection and numerous other factors.
Effects of Biodiesel Fuels on the Permeation and Mechanical Properties of Coated Fabrics Used in Collapsible Fuel Storage Tanks
The purpose of this work was to perform a comparative analysis of various candidate nitrile coated fabric materials supplied by potential vendors to be used as fuel storage tanks and compare the results to the currently fielded polyurethane storage tanks. Our results demonstrate that the nitrile coated fabrics performed well in our evaluation. Their breaking strengths are about equal to the currently fielded urethanes and they performed much better as barrier materials after ageing.
The Sole Effect of Lateral Stress on Solids Conveying
The lateral stress ratio of the solid feed resin has been shown to be a key factor in solids conveying. The lateral stress ratio has also been measured to be a function of primary stress, and it can vary significantly. Modeling of solids conveying is done to illustrate the effect of different stress ratio functions of polyethylene on solids conveying. Experimental results are used to validate the model and the fact that normal variations in lateral stresses are significant in solids conveying performance.
Cyclic Olefine Copolymer (COC) Nanocomposites and Nanocomposite Foams: Preparation, Morphology and Properties
Cyclic olefin copolymers (COC)/ multi-wall carbon nanotubes (MWCNTs) composites of different carbon nanotubes (CNTs) concentration were prepared by melt blending. The dispersion of the CNTs in the polymer matrix was investigated by scanning electron microscopy (SEM). The rheological property and the electrical conductivity of the nanocomposites were studied. In addition, the nanocomposites were foamed by carbon dioxide, and the effects of the CNTs on the foam cell morphology were investigated.
Dynamic Heating of Injection Molds Using an External High Power Diode Laser Scanner
By using dynamic mold temperature control in injection molding, parts with special features such as functional micro structures or high gloss surfaces can be produced in a one-step process. Due to limitations of available mold heating techniques, an innovative system using an externally robot-guided laser scanner was developed and implemented at the Institute of Plastics Processing (IKV) at RWTH Aachen University. High heating rates, a focused, discrete heating of specific cavity areas and the flexible, mold independent set-up are key aspects of the technology.
We're sorry, but your current web site security status does not grant you access to the resource you are attempting to view.