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The study was made by modifying the simulation mesh model characteristics to mold normalized test specimens. The simulation results were obtained through a filling/cooling simulation program for the injection molding process. The simulated filling time, optimum cycle time and injection pressure, seemed to be influence by the number of elements model. A best agreement between experimental and simulation results were obtained by increasing the number of elements of the mesh model.
The determination of the relaxation modulus using the step imposition of a strain is an important step in the fitting of the parameters of viscoelastic constitutive equation. In the nonlinear region the true shear strain imposed on a polyethylene melt is found to deviate considerably from the targeted strain due to the presence of wall slip which is documented here. The presence of the wall slip reduces the range of strains for which the strain-dependent relaxation modulus can be determined for the linear polyethylene melt investigated.
The effects of dynamic vulcanization on the morphology and mechanical properties of rubber/plastic blends are investigated. This study includes the discussion of why the mechanical properties differ before and after dynamic vulcanization. Enhanced interfacial adhesion by dynamic vulcanization was found to be a major contributor of superior tensile strength of TPV. Rubber elasticity of TPV is a result of the combined effects of crosslinked rubber, morphology, and amorphous PP phase plasticization.
Stephanie L. Bullard, Matthew M. Jackson, May 2002
The strength and viscosity of polypropylene is influenced by extreme stress during the injection process. By varying backpressure of the material in extreme conditions the strength of the part will decrease. Reduced strength of the part will be proven through tensile and impact testing. Numerous material generations of polypropylene will be compared to virgin polypropylene to prove the decrease in strength.
A number of lubricants have been evaluated in polymer-wood composites. These lubricants have been evaluated in both HDPE-oak and HDPE-pine composites. Properties measured included extruder torque levels, outputs, extruder shear heating, and visual assessment of extruded part appearance.
Ryan T. Paszkowski, Kathryn E. Garnavish, May 2002
The imbalance between the cavities in a geometrically balanced, multi-cavity mold used for injection molding has previously been explained in theory as shear induced imbalances". (1) The cause of these imbalances can be from uneven shear effects on the melt as it travels to each cavity through the runner. This paper presents a study which finds that the machine nozzle and sprue can have a significant contribution to shear induced mold filling imbalance. The effect of geometry material and process are evaluated."
The Permeability of polyethylene limits it's use in applications where oxygen barrier properties are required. Polyethylene, an extremely non-polar molecule, exhibits low permeation levels with polar substances such as water. Conversely, non-polar gasses such as oxygen exhibit high levels of permeation. A silicate nanocomposite was added to reduce the permeation of non-polar gasses while maintaining the low permeation of polar substances. The polyethylene nanocomposite provided better oxygen permeation properties than traditional grades of polyethylene.
A new chlorinated polyethylene has been developed for the impact modification of rigid PVC. In addition to imparting excellent impact, the modifier promotes faster PVC fusion, and enhances the formulation's melt strength. Faster fusion allows for economic savings by reducing fusion promoting ingredients and via higher output. The enhanced melt strength results in better part quality, especially for complex profiles.
Low levels of acrylics are widely used as impact modifiers and processing aids for rigid PVC. At higher levels, acrylics can also significantly improve the long- term weatherability of PVC. Here we report on the ongoing results of a long-term outdoor weathering study of PVC/acrylic blends. Acrylic level, stabilizer type, and weathering location all affected the property retention of the weathered specimens. With proper formulation, the acrylic blends resulted in a significant improvement in the weatherability of the samples versus the PVC controls.
Zoran S. Petrovi?, Wei Zhang, Randy Miller, Ivan Javni, May 2002
Epoxidized soybean oil was cured with citric acid, phthalic anhydride and Lewis acids. Lewis acid initiators and citric acid gave rubbery materials of relatively low strength and low glass transition. Aromatic anhydrides give glassy polymers when equivalent ratio of anhydride to epoxy group is used. Mechanical strength of rubbers is relatively low but that of the glassy materials is typical for plastic materials.
Cody D. Greene, Ian S. Laskowitz, John E. McConnell, May 2002
Pinch-off weld line strength is crucial in ext rusion blow molding. This experiment is intended to determine and quantify the processing parameters and design parameters that will produce the strongest weld line strength. Using a 3 level Design of Experiment (DOE) for making the test specimens, the specimens were tested for tensile strength. This data was then used as a guide for producing quality pinch-off weld lines with less guesswork.
It has been observed that a filling imbalance occurs with powdered metal injection molding in multi cavity molds using geometrically balanced runners. This imbalance is typically opposite to the shear induced imbalance developed n these runners with conventional plastic materials The causes and effects of this reversed condition is studied and alternative runner designs evaluated to reduce the imbalance. The alternative designs include the use of the MeltFlipper technology that has proven to solve the imbalance with conventional plastic materials.
An elastic-plastic finite element analysis of the quasi-static loading of two acetal copolymer gears in contact is preformed. Load verses rotation of the gear set is compared to actual experimental results. The gear geometry is modeled by plane strain elements with variable thickness between the rim and web. Gear tooth failure is modeled by both deactivating and separating elements when the tensile strength is exceeded. Failure in the tooth root is best modeled by a nonlinear approach using separating elements.
Gregory A. Campbell, Hongying Cheng, Chicheng Wang, Matthew Bullwinkel, Mary Ann te-Riele, May 2002
The focus of this investigation was to experimentally determine the effect of barrel rotation and screw rotation viscous dissipation inside the screw pump-extruder. The experimental results can be summarized by noting that barrel rotation generated higher temperature rise than screw rotation. Results are presented for seven screw configurations.
Susan A. Somers, Mark A. Spalding, Joseph Dooley, Kun Sup Hyun, May 2002
A comparison is made between the melting, pumping, and mixing characteristics of a single-screw extruder with an Energy Transfer mixing section and a conventional screw without a mixing section. Results are given for extrusion trials, extrudate sampling, and extrusion solidification experiments performed at different screw speeds and color concentration letdown ratios.
Four homopolymer high density polyethylene (HDPE) resins were evaluated for their blown film properties. Film was blown in both conventional linear low density polyethylene (LLDPE) configuration and high molecular weight - high density polyethylene (HMW-HDPE) configuration. Water vapor transmission rates were reduced by nearly 50% in the HMW-HDPE configuration for the narrow molecular weight resins. Haze increased and gloss decreased for the same polymers. The broad molecular weight polymer showed only small changes in these properties.
Technological improvements of flexible form, fill and seal packaging machines are yielding exceptional line speeds, productivity rates and bag features. This paper discusses the evolution of vertical packaging machine development and how it has impacted plastic film properties (e.g. COF, sealing temperature range, hot tack) required for optimal performance.
Heat sinking in electronic components in VLSI can be any method by fin assemblies in different configuration. The periodic heating is studied using hyperbolic heat wave propagative equation complex variables. The flux reversal is studied.
E. Takács, J. Vlachopoulos, C. Rosenbusch, May 2002
A fundamental study of the microcellular foamed structure in rotational molding was conducted by using polymer microspheres as a blowing agent. The influence of the viscosity, temperature dependence of viscosity and first normal difference of different resins on the cell morphology and the tensile properties of the foamed parts was investigated.
Eric E. Stangland, Joseph Dooley, Mark A. Spalding, EungKyu Kim, Kun Sup Hyun, May 2002
It is known industry wide that polypropylene (PP) resins plasticate in single-screw extruders at rates that are less than those for linear low density polyethylene (LLDPE) resins. The goal of this research is to show the magnitude of this rate reduction, and the physical properties related to processing that are causing the rate reduction.
Kim McLoughlin Senior Research Engineer, Global Materials Science Braskem
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Kim drives technology programs at Braskem to develop advanced polyolefins with improved recyclability and sustainability. As Principal Investigator on a REMADE-funded collaboration, Kim leads a diverse industry-academic team that is developing a process to recycle elastomers as secondary feedstock. Kim has a PhD in Chemical Engineering from Cornell. She is an inventor on more than 25 patents and applications for novel polyolefin technologies. Kim is on the Board of Directors of SPE’s Thermoplastic Materials & Foams Division, where she has served as Education Chair and Councilor.
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Gamini has a BS and PhD from Purdue University in Materials Engineering and Sustainability. He joined Penn State as a Post Doctorate Scholar in 2020 prior to his professorship appointment. He works closely with PA plastics manufacturers to implement sustainability programs in their plants.
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Tom Giovannetti holds a Degree in Mechanical Engineering from The University of Tulsa and for the last 26 years has worked for Chevron Phillips Chemical Company. Tom started his plastics career by designing various injection molded products for the chemical industry including explosion proof plugs and receptacles, panel boards and detonation arrestors for 24 inch pipelines. Tom also holds a patent for design of a polyphenylene sulfide sleeve in a nylon coolant cross-over of an air intake manifold and is a Certified Plastic Technologist through the Society of Plastic Engineers. Tom serves on the Oklahoma Section Board as Councilor, is also the past president of the local Oklahoma SPE Section, and as well serves on the SPE Injection Molding Division board.
Joseph Lawrence, Ph.D. Senior Director and Research Professor University of Toledo
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Dr. Joseph Lawrence is a Research Professor and Senior Director of the Polymer Institute and the Center for Materials and Sensor Characterization at the University of Toledo. He is a Chemical Engineer by training and after working in the process industry, he has been engaged in polymers and composites research for 18+ years. In the Polymer Institute he leads research on renewably sourced polymers, plastics recycling, and additive manufacturing. He is also the lead investigator of the Polyesters and Barrier Materials Research Consortium funded by industry. Dr. Lawrence has advised 20 graduate students, mentored 8 staff scientists and several undergraduate students. He is a peer reviewer in several journals, has authored 30+ peer-reviewed publications and serves on the board of the Injection Molding Division of SPE.
Matt Hammernik Northeast Account Manager Hasco America
A Resin Supplier’s Perspective on Partnerships for the Circular Economy
About the Speaker
Matt Hammernik serves as Hasco America’s Northeast Area Account Manager covering the states Michigan, Ohio, Indiana, and Kentucky. He started with Hasco America at the beginning of March 2022. Matt started in the Injection Mold Industry roughly 10 years ago as an estimator quoting injection mold base steel, components and machining. He advanced into outside sales and has been serving molders, mold builders and mold makers for about 7 years.
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Any article that is cited in another manuscript or other work is required to use the correct reference style. Below is an example of the reference style for SPE articles:
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, ISBN: 123-0-1234567-8-9, pp. 000-000.
Available: www.4spe.org.
Note: if there are more than three authors you may use the first author's name and et al. EG Brown, H. L. et al.