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.
The study includes two fillers (wheat straw and talc; from 20 to 40wt %) and two polypropylenes (homopolymer and impact copolymer). The combined effect of the fillers at 30wt % was also evaluated. Mechanical properties and density were measured. The flexural modulus increased with filler level. In case of polypropylene copolymer, increasing the percentage of filler/fiber decreased the impact strength of the composite. Each filler had a different contribution to the specific flexural modulus.
K-ionomer antistatic agent is highly effective in polyolefin host resins. In addition to the many unique features it imparts to the end-uses, the K-ionomer shows good compatibility with polyolefins and is easy to process. This paper presents an in-depth discussion on several material and processing factors that need to be properly controlled in order to achieve a favorable blend morphology and further improve the antistat performance.
In plastics processing industry does exist the trend of miniaturization. Control of all production parameters, especially control of pressure, plays a decisive role influencing the quality of products produced with injection molding and extrusion. When downscaling the size of products to microproducts control of pressure gets more important and difficult. This work investigates the possibility to apply the Bagley correction in microchannels to determine the drop of pressure in cross-section reductions without using pressure sensors.
Molding shops and mold builders realize more and more that the continued practice of a re- active “fixes it when it breaks” maintenance strategy is an exercise in futility. Excessive tooling and labor costs, missed production shipments and repeating part quality issues caused by knee jerk solutions and quick, cheap repairs stifle company growth. Changing a long standing re-active maintenance culture involves understanding the “5 factors of focus” that control tool room performance.
Thermoforming is an economical process for forming large shape products. High performance liquid crystal polymer (LCP) has high thermal stability, excellent dimensional stability and high chemical resistance, which offers new application opportunities in demanding applications. In this paper, a new thermoformable LCP resin is compared with injection molding LCP on mechanical, thermal and rheological properties. Sheet extrusion and thermoforming process conditions are discussed.
The effects of cooling rate on gas penetration depth and residual wall thickness (RWT) of gas-assisted injection molding (GAIM) parts was investigated for polypropylene (PP) and for stainless steel powder feedstock (SSPF). Gas penetration depth and RWT of PP in SLA and in Al cavities did not show any significant difference. However, gas penetration and fingering of SSPF in SLA and in Al cavities were found to be different.
In this study, the long GFR-PPS and short and long GFR-SPS were tested to evaluate the long-term performance at the elevated temperature in water and in air. As a result, tensile strength of there after 10000 hours at 150°C in hot water decreased to 60% or less due to degradation at the interface between matrix resin and GF.
This research was performed to compare mechanical properties of wood-plastic composites based on PLA and PLA/PBS blend. Wood-plastic composites were prepared by melt compounding 70 wt% plastics; PLA, PLA/PBS 70:30 wt% blend, or PP; and 30 wt% pine wood fibers. A suitable coupling agent was used to improve compatibility between polymer matrix and wood fibers. Tensile, flexural, impact and fracture toughness were evaluated and compared. Phase dispersion and interfacial adhesion was studied by SEM.
Properly used and maintained Porcerax II, the self venting mold steel, will allow molders to reduce cycle times, injection pressure and scrap due to short shots, sink, and material burning. Design considerations should include: 1. Resins used 2. Surface finish of plastic part required 3. Size of problem area 4. Proper thickness of insert 5. Proper venting on cavity and backside of insert for optimal venting. 6. Molding vertical walls with Porcerax II 7. Ability to remove the insert for periodic cleaning
This research was evaluated the adsorption and barrier properties of PET, PP. The results showed that MVTR of the blend samples decreased with increasing PP contents while the residual rate of L-menthol decreased when increasing PP contents in blend. Therefore, the adsorption amount of a model compound, L-menthol tended to increase with increasing PP contents in the blends. However, the barrier effectiveness of the blends has been improved by the contribution of the PP.
Three general purpose polycarbonate (PC) resins and one PC-siloxane copolymer were injection molded, then exposed to isopropyl alcohol (IPA), hand lotion, and SPF 30 sunscreen while under strain. The hand lotion exhibited the most aggressive environmental stress cracking (ESC) behavior. Effects of molecular weight, polymer composition and annealing are addressed. Scanning electron microscopy of an ESC fracture surface is also presented.
Nanocomposites of HNBR latex and modified clays were prepared by latex blending. The results of x-ray diffraction show that using a reswell technique with trisilanolphenyl POSS with MMT and rubber provides a large d-spacing as well as a mainly exfoliated structure. Modified clay in the latex affords no change in thermal degradation temperature. POSS modified clays successfully provide thermal stability and an intercalated or exfoliated structure when mixed with latex rubber.
This study was carried out to clarify a relationship between moisture absorption fraction and higher-order structure of dry-less recycled PET pellets. Karl Fischer moisture titration, differential scanning calorimetry (DSC), microscopic Raman spectroscopy and scanning electronic microscope (SEM) were used to characterize the pellets to determine distinct structures that differentiates the dry-less pellets with normal pellets.
Manufacturing spherical polymer micropellets has been possible with a new technique that uses air to impose surface disturbances on an extrudate. Observations of experimental results considering properties of the melt are taken as the starting point for a deeper understanding of the behavior of polymer resins of interest in the production of micropellets. Such relationships include aspects of material properties as well as processing conditions.
On September 16, 2011, the President of the United States signed into law the Leahy-Smith America Invents Act. This law includes some of the most significant changes to U.S. Patent Law since the early 1950’s, changing the U.S. patent system to a “first to file” system. The Act also introduces procedures, such as post grant review and supplemental examination, and alters existing procedures such as inter-partes re-examination.
This paper presents the possibility of using natural fiber as reinforcement for engineering thermoplastics composite. Jute mats from waste coffee bag were treated by thermoset resin such as flexible epoxy resin (FE) to improve their thermal resistance prior to compression mold with polycarbonate (PC). The effects of epoxy contents on thermal properties and mechanical properties of the composites were investigated.
The paper describes the study of a flow instability defect in a coextursion, cable coating process. The problem was first analyzed using a 2D Finite Element flow simulation. It was determine that the outer layer was experience very high deformation (velocity changes) when merging with the next inner layer. The problem was solved by modifying the coextruson die to reduce the velocity differences that the material experienced in the merge region. This modification stabilized the coextrusion process and removed the instabilities so that acceptable product could be made
The effects of talc content and injection flow rate on the foaming behavior of injection-molded microcellular polylactide (PLA) were investigated. Cell morphology with a cell size of less than 20 µm and cell density of greater than 108 cells/cm3 was successfully produced. The addition of 5 wt % talc to PLA increased the cell density roughly ten times and decreased the cell size about three times. Also, higher injection flow rate resulted in finer cells with greater density.
Compounding lines that utilize single-screw extruders as the pumping device for pelletization can be severely rate limited if the metering channel of the single-screw machine is not optimized for the process. This paper provides the troubleshooting methodology for solving this type of problem using a case study.
Developing new cost-effective polymer products is challenging in the current competitive marketplace. Electron beam irradiation is a powerful tool used to improve the properties of a wide range of materials, particularly polymers, and has been used to gain a competitive advantage in many successful commercial products. This paper reviews three case studies in the development of new polymer products using electron beam irradiation and the role of the electron beam processor.
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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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