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.
Research objective is to establish manufacturing-related design rules and procedures for engineering design of injection molded thermoplastics parts, and to investigate application of novel materials to support development of design for sustainability. Thorough analysis of a large number of mechanical test results has led to a better understanding of factors influencing mechanical performance in tensile and tensile-impact. Among the noteworthy conclusions is the importance of shear rates and temperature gradients in the surface layers during molding.
A methodology in producing highly functional designs is discussed. The family of injection molding processes referred to as Structural Plastics offers product designers more design liberty with net-shape moldings with highly functional and value added features. Functionality determines which process and resin should be specified through cost/benefit analysis.
Risk is inherent in the production of any molded part stemming from, for example, changes in production quantities, uncertainty in molding behavior, redefined product specifications, failures in equipment, and abandoned supplier relationships, and other causes. This paper provides several strategies for hedging these risks by considering the cost of the changes to correct different failure modes in the design. The objective is to improve product performance while reducing time to market and risk.
According to one major industry study, 45% of all field failures involving parts fabricated from plastic materials can be attributed, at least in part, to an incorrect material selection. This paper will highlight several case studies involving failures due to improper material specification and will discuss solutions to these failures.
Failures generally are due to problems of design, composition or processing. In this paper, examples are given in which failure was due primarily to composition. In some cases, components of the known formulation were at fault. In others, contaminants introduced externally were the cause of failure. Among the types of failure were odor, color, materials sticking together unintentionally and other problems resulting from transfer of formulation components to other materials.
In the present paper an approach for modelling SMC material as visco-elastic damageable is presented. Damage theory by Chow and Wang is used in combination with linear visco-elasticity. The model is exemplified through application to uniaxial creep test with material of different damage states. Simultaneous testing and simulations on a modern SMC material is performed with good accuracy, especially at moderate damage levels.
Samples of polypropylene (PP) and PP nanocomposites with 1, 2, 3, and 5 % of Montmorillonite layered silicate (MLS) were tested in three-point bending conditions. Techniques of crack tip opening displacement (CTOD) and J-integral are used to determine the influence of MLS on this feature of the material. Fracture toughness was obtained for each one of the systems mentioned. It was found out that the addition of 5 % MLS reported the highest impact on the properties.
Scratch behaviors in several types of plastics have been investigated in order to develop scratch test method for plastics. The effects of scratch conditions such as scratch speed and normal load on the strength reduction have been discussed on the basis of absorbed energy obtained by carrying out the Charpy impact test after scratching (CAS for short). The effect of scratch has been studied by comparing the absorbed energy of CAS with that of Charpy impact test using both notched specimens and un-notched specimens. It is noted that scratches led to strength reduction in several plastics.
High performance clear TPE products are developed to replace silicone and PVC in various medical and personnel care applications. These are high clarity TPEs with high tensile and tear properties. They retain mechanical properties and dimensional stability after hours of testing in boiling water and repeated dishwasher cleaning cycles. These TPEs have good processability. They can be used in FDA and USP required applications.
EPDM rubber concentrates have been developed by DSM Thermoplastic Elastomers. This new line of products consists of three low durometer grades. These rubber concentrates are designed for toll compounders to make TPVs of different durometers (medium to high) and different properties by adding various amounts of polyolefin plastics, such as polypropylene (PP) and other ingredients, to the rubber concentrates on a twin screw extruder or on other mixing equipment with sufficient mixing capability.
In an effort to develop better teaching approaches for engineering courses, academia is taking a look at alternative styles that implement advanced educational tools as an alternative to lecture-based courses. As the World Wide Web matures, multimedia and programming technologies are evolving to enable the development of instructional software containing significant depth and interactivity. This paper discusses the development and integration of web-based tools to support engineering courses.
Addition of Stretch Blow-Molding capability to the Plastics and Polymer Engineering Technology Program at Pennsylvania College of Technology is described. Through a grant from the National Science Foundation, process and analysis equipment was purchased to enhance courses in blow molding, process survey, and advanced processing courses. Copies of laboratory experiences are available nationally on a web site or through correspondence with the author.
There are many ongoing activities taking place in the regulatory arena regarding organotin stabilizers used in PVC. This paper will provide an overview of the activities, including who is involved and what the issues are. It will also describe how the stabilizer industry is dealing with these issues as part of their ongoing efforts to insure that the use of organotin stabilizers is approved and continues to be safe for people and the environment.
This paper provides an insight on the relationship between the physical properties of the profiles extruded from flexible PVC compounds and the extrusion melt temperature. The properties include tear resistance, tensile properties, brittleness temperature and compression set. The effect of heat history on surface characteristics of the extrudate, such as surface roughness and gloss, and their relationship with the processing morphology is also discussed.
The ductile-to-brittle transition (DBT) is observed for PVC siding samples using an instrumented dart drop impact tester. Large numbers of test specimens from each sample were evaluated for impact strength to establish a clear indication of bimodality. For a particular sample, a DBT temperature determined from this method may be used to determine impact modifier efficiency, or as a robust quality control check for commercial siding producers.
The stabilization and degradation of PVC by methyltin alkyl thioglycolates was investigated by molecular orbital calculations of the most probable reactions responsible for them. Theoretical studies confirmed previously postulated mechanisms based on experimental results.
The packaging industry uses ethylene ionomers for their unique balance of properties, such as high stiffness and low heat seal initiation temperature. These properties result from complex interactions between ionic and crystalline phases. We use studies of ionic strength, crystallization kinetics and thermal analysis to show how these phases form. This new understanding explains how stiffness develops in ionomers and its role in optimizing flexible packaging performance.
WHY A PACKAGE???CONTAINMENT MARKETING PROTECTION
A detailed two-dimensional simulation of the film blowing process is developed based on a mathematical model that incorporates the Phan-Thien Tanner (PTT) and Neo-Hookean constitutive equation with crystallization effects. The PTT constitutive equation is employed in the hot region, while the Neo-Hookean constitutive equation is used in the cold region to describe the rheological behaviour of the film. The model predicts bubble shape dimensions, temperature distribution, crystallinity, and orientation.
On line refractive index measurement for the determination of conversion ratio in the course of PMMA bulk polymerization was developed using He-Ne laser beam with CCD camera. The Snell’s law was applied to interpret the refraction pattern in CCD camera to calculate the refractive index. It is shown that refractive indexes of MMA/PMMA mixtures vary linearly with conversion ratio in bulk polymerization. Mathematical correlation was developed to fit the experimental data.
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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
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