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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Self-Optimizing in Injection Molding and the Problem at Compensating Viscosity Fluctuations
A self-optimizing injection process can compensate temperature fluctuations. But viscosity fluctuations are not considered in this concept, yet. Modifying the injection flow rate can balance the shrinkage potential but results although in varying residual stresses.
Innovative Plasticizing Method for Micro Injection Molding
The process reproducibility during injection molding of micro components is often bought on an unnecessarily large dosing volume. To enable an economical production of micro components, a reduction of the material consumption is crucial. Therefore new production strategies need to be developed to reduce the required plasticized mass to a minimum while maintaining part quality at the same time. In the context of this paper, an innovative plasticizing method for micro injection molding is introduced, tested on its feasibility and analyzed in detail on its conveying and homogenizing characteristics.
Development of Low Gloss Polyacetal
Nowadays low gloss Polyacetal (POM) materials are required for automotive interior parts. In this study, new low gloss POM was developed. Original organic particles having effective interaction with POM, was developed as the matting agent. Consequently, excellent low gloss appearance with a good balance of mechanical properties is obtained. In addition, weather resistant and low VOC (Volatile Organic Compounds) emission technology could be applied to this low gloss POM.
Steady State and Response Time Temperature Validation for a Multivariate Injection Molding Sensor
An infrared temperature sensor is detailed using a thermopile with an incorporated thermistor into a standard Dynisco snout. A testing apparatus was built to measure the temperature of a heated polymer at steady state. The apparatus was also used to validate the response time of the multivariate senor. Results show the multivariate sensor can accurately measure temperature with a response time of approximately 200 milliseconds.
A Two-Dimensional Iterative Learning Model Predictive Control Method for Injection Molding Based on Mixed Integer Quadratic Programming
Batch processes like injection molding are inherently a two-dimensional process with multi-phase dynamics. The transient period from one phase to the next is always difficult to control due to the significant change of process dynamics. In this paper, a new two dimensional method based on mixed integer programming is proposed to improve the performance during the transient period. Switch condition is formulated as constraints of an optimization problem. Simulation results are listed to show the efficiency of the algorithm.
Virtual Prototyping Applied to Flat Extrusion Die
This paper discusses the use of virtual prototyping for industrial extrusion die. We used numerical simulation to analyze the flow behavior in a PVC extrusion die. First, 3D isothermal simulation is used to investigate the flow uniformity at the outlet section of an extrusion die for 3 different internal geometries. Then, 3D non isothermal simulation will be used to see the impact of specific temperature profile at the entrance of the die on the flow uniformity. The shape of a flow channel was evaluated and the reason of a flow problem in practice was found by using this software.
The Development of a CAD/CAE Integrated Wizard Design System for Injection Mold
For injection molding simulation, the model reconstruction is an obstacle in the application, because the computer-aided design (CAD) systems and computer-aided engineering (CAE) systems are realized as isolated modules. In order to improve the quality and efficiency of simulation, a CAD/CAE integrated wizard design system is developed, which is based on the commercial CAD and CAE systems. In this system, the mold design task can be efficiently completed and the CAE data can be automatically obtained with the support of some certain procedures and the powerful tools.
Novel Plasticizer Alternative for Polyamide Polymers
Flexil™ is a novel modified organosilicon based additive developed and marketed by Polymer Dynamix, LLC in South Plainfield, NJ. Flexil™ provides properties of flexibility to polyamides over a wide range of temperatures from less than -50°C to greater than 300°C. The results demonstrate that Flexil™ can replace various traditional plasticizers in polyamide compositions.
Reaction Extrusion of Polyurethane Based on Renewable Sources
This manuscript studies the reaction extrusion of polyurethanes based on both polytetramethylene ether glycol (C4) and polytrimethylene ether glycol (C3) polyols using a twin screw extruder. Polyurethanes (TPU) with hardness of 70A, 85A and 50D were fabricated. The two polyols showed comparable reaction kinetics with methylene diphenyl 4,4'-diisocyanate (MDI). C3 polyol polyurethanes showed slightly lower tensile stress at the same hardness level. But they showed comparable tear strength. C3 polyol TPUs needed slightly higher hard block to obtain the same hardness.
3D Characterization of Compression Molded HDPE/Wood Fiber Composites
The fiber orientation distribution in a material sample was analyzed. A micro tomography reconstruction of the sample was used to derive the components of a fabric tensor from an evaluation of the global anisotropy parameter. This parameter proved to be an efficient tool for the analysis of the structure of fiber reinforced composites. The local variations of the degree of anisotropy (ratio of the maximum and minimum eigen values of the fabric tensor) from the shell to the core layers of the sample can be captured and information about the local average fiber orientation angle can be obtained.
Production of Bio-Based Polyethylene from Sugar Beets
A 22% solution of sucrose derived purely from sugar beets was dissolved in water and hydrolyzed with an invertase enzyme to produce glucose. This glucose was fed to champagne yeast and fermented to produce ethanol in yields of approximately 15 %. The ethanol was catalytically dehydrated to ethylene with a HZSM-5 catalyst in a small batch reactor. The ethylene was converted to poly(ethylene) using a Ziegler-Natta type catalyst. This poly(ethylene) should be suitable for use in plastic products like plastic bottles, containers, and grocery bags.
Modification of Melt Strength of Polypropylene via UV Radiation
Melt strength (MS) of polypropylene (PP) has been modified by utilizing benzophenone (BPH) as photoinitiator along with UV radiation. Processing conditions were manipulated to promote long chain branching (LCB). Formation of long chain branches and/or crosslinks was confirmed using linear viscoelastic (LVE) measurements, extensional rheometry, gel content, and gel permeation chromatography (GPC). Results clearly indicate that MS of PP has been successfully modified without significant gel formation.
Tunable Synergistic Property Enhancements in Green Polypropylene Composites with Waste Paper and Cardboard via Solid-State Shear Pulverization: Size Reduction and Dispersion
Synergistic green composites of polypropylene (PP) with cardboard and waste paper are produced via solid-state shear pulverization (SSSP) without any compatibilizers or surface modification. The property enhancements are comparable to those from more expensive forms of cellulose. Additionally, optimization of SSSP processing, commercial viability and melt processability of the composites are evaluated.
Wire Sweep Analysis in Transfer Molding and Compression Molding Process for Semiconductor Chip Encapsulation
A simulation program for prediction of wire-sweep during transfer molding and compression molding of thermoset materials for semiconductor chip encapsulation has been developed. The flow simulation necessary for wire-sweep analysis is based on a three-dimensional model. The simulation results were compared to the experimental results from an industrial case of transfer molding. A method to reduce wire sweep during transfer molding and compression molding is also discussed.
Surface Energy of a Polyurethane as a Function of Film Thickness
The segmented polyurethane, Estane is a polyester-urethane (poly(butylene adipate)-poly(4,4'diphenylmethane diisocyanate-1,4 butanediol. In the present paper, conventional contact angle experiments have been performed and the surface energies of the Estane sample as a function of film thickness have been determined. In addition, thermal analysis has been used to measure the calorimetric glass transition (Tg) for this segmented elastomer. Moynihan’s area matching method was used to determine the limiting fictive temperature.
Effect of Polycarbonate Oligomer on Internal Structure and Mechanical Property of Injection Molded Polycarbonate
In this study, the effect of polycarbonate oligomer (PC-O) addition on thermal properties, internal structure and weld properties of injection molded polycarbonate (PC) were investigated. It’s suggested that PC-O addition to PC is effective to flowability increase and improving surface roughness of V notch maintaining good mechanical properties compared with PC which has equivalent flowability.
Some Physico-Chemical Structural Factors Affecting the Performance of Oxygen Scavenging Additives in PET
The structural and morphological factors affecting the reactivity and performance of some oxygen scavenger additives in PET blends are reviewed. Role of the catalyst action and the effect some activators in oxygen scavenger chemistry have also been briefly investigated.
Factors Impacting Formulation Development of Extruded Polystyrene Foam
Extruded polystyrene (XPS) foam has been a useful and cost-effective thermal insulation for commercial and residential buildings for over 50 years. Producers have responded to a variety of factors, such as, environmental regulations, building codes, and energy costs, to obtain effective alternative XPS products. This paper reviews XPS insulation formulations with blowing gases, HFC-134a and HFC-152a, that have long-term thermal performance to meet or exceed current codes. The developed XPS insulations have zero ozone depletion potential and provide a sustainable benefit to society.
New Technology for the Coloring of Rotationally Molded Products
This paper will describe a new technology for the coloring of rotomolded plastic parts that will contain a pearlescent effect pigment and show a superior finished look to dry blended materials in the past.
Properties of Co-Extruded Multilayer Packaging Films from Biopolyethylene and Milled Soy Flour
Multilayer packaging films from bio-polyethylene/soy flour composites were produced via co-extrusion processing through feedblock technology. Three layer films were produced containing up to 20% milled soy flour in the core layer, with neat polyethylene skins. Oxygen permeability of the films decreased by as much as 38% with the addition of soy flour to the core layer, but tensile strength values decreased by 29% in comparison to the neat multilayer control.
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