SPE Library
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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Recycling
RISING TO THE HALOGEN CHALLENGE IN FLAME-RETARDANT ENGINEERING PLASTICS
William J. Hassink , Gary P. Kozielski, May 2010
Halogenated additives have long been used toenhance the flame-retardant properties of plastics.Recently, after many years of growing concern over theenvironmental and human impact of the disposal ofcertain halogen-containing products and theirincompatibility with recycling operations, leading globalelectronics manufacturers have begun moving to eliminateor sharply reduce the use of certain halogen-containingingredients in their products. DuPont is meeting the needsof these and other environmentally consciousmanufacturers with a growing range of engineeringpolymer grades using non-halogenated flame retardantsystems. This paper shows that they can fulfilldemanding requirements for strength, toughness, hightemperature resistance and processing efficiency.
ROOT CAUSE INVESTIGATION OF CRACKED POLYCARBONATE FOOD BLENDER JARS
Divya Kosuri, Sunny M. Ogbomo, Nandika A. D’Souza, May 2010
Polycarbonates find applications in food industries due to their clarity and ductility. Sometimes failure of a polycarbonate part occurs. In food blender jars molded from polycarbonate, cracks were observed in the sealed joint only a few days after assembly. The root cause was investigated via microscopy, FTIR and GC-MS analyses. It was determined the cracks initiated and radially propagated from the bottom raised lip of the part. The root cause was a combination of a high stress in the lip region due to molding and design, and environmental chemical compounds, i.e., esters from a melt nut used in the assembly. The failure was typical environmental stress cracking (ESC) problem.
SENSITIVITY OF MECHANICAL PROPERTIES OF POLYAMIDE-IMIDE TO LOT-TO-LOT VARIABILITY
Alan I. Kasner , Patrick J. Murray , Barbara A. Harris, May 2010
PAI (Torlon) is used in aerospace applications requiring excellent mechanical properties at high temperature, fluid resistance, and thermal stability. PAI is a delayed cure thermoset that reaches its ultimate properties and maximum Tg only with an extended postcure. This work examined the correlation of Tg and properties of four injection molded lots of PAI. Testing consisted of impact strength measurement, tensile and flexural strength and modulus testing at various temperatures and after different environmental conditioning. CTE in three orthogonal directions were measured and creep testing was run on samples after different environmental exposures, including long-term aging in turbine oil.
SHARKSKIN MELT FRACTURE CHARACTERISTICS OF POLY (HYDROXY BUTANOIC ACID) COPOLYMERS
I. Nishi, S. Matsubara, Y. W. Leong, H. Hamada, A. Goto, May 2010
Recent advances have rendered bio-based and biodegradable PHB (poly hydroxybutanoic acid) copolymers suitable for many extrusion applications. The high molecular weight and narrow distribution of melt relaxation times of these polymers can sometimes cause sharkskin melt fracture to occur during extrusion. This may be a limiting factor for their wide-spread applicability. This presentation will discuss the characterization of sharkskin melt fracture of these polymers using capillary rheometry including the identification, for the first time, a critical criterion for their occurrence.
SILICONE BASED FLAME RETARDANT FOR POLYCARBONATE
Wolfgang Abele , Yukihito Ozaki , Takeshi Chiba , Kazunori Saegusa, May 2010
Kaneka Corporation has developed a silicone based flame retardant for Polycarbonate, Kane Ace MR-01. MR- 01 realizes non-bromine and non-phosphorus flame retardant PC compound and increases low-temperature impact strength. Kaneka's renowned graft polymerization technology makes it possible to disperse the cross-linked silicone particle into Polycarbonate matrix. MR-01 achieves V-0 in UL-94 protocol at 1.2 mm thickness (Kaneka's evaluation data) with a small amount of PTFE. MR-01 also has excellent thermal stability, which provides with superior impact strength retention after heat aging, and maintains the flame retardancy after recycling process.
SINGLE SCREW EXTRUSION OF BIOBASED AND BIODEGRADABLE POLY (HYDROXY BUTANOIC ACID) COPOLYMERS
Rajendra K. Krishnaswamy , Jason Baird , John P. Christiano, May 2010
The complex time and temperature dependent melt rheology of Poly (Hydroxy Butanoic Acid) or PHB copolymers is an important consideration for their extrusion. In this effort, we report the influence of temperature profile and screw design on the process stability, melt temperature, melt pressure, output rate and molecular weight retention using highly-instrumented commercial-scale extruders with smooth-bore feed sections. One important outcome of this investigation is screw design guidelines for the extrusion of PHB copolymers.
SMC REPLACEMENT WITH ENGINEERING THERMOPLASTICS IN HEAVY COMMERCIAL VEHICLE BODY PANELS MARKET SPACE
N. Venkatesha , Claes Lindberg , Stefan Johannesson , Derek Buckmaster, May 2010
Traditionally body panels of Heavy Commercial Vehicles (HCV) are built in Sheet Molding Compound (SMC) or metal. OEMs are looking for fuel-efficient, lightweight and greener technology solutions.The specific gravity of Engineering Thermoplastic (ETP) is much lower and offers significant weight reduction opportunity over SMC/metal. This paper presents limitations of SMC, key challenges in terms of aesthetics and high flow length to thickness ratio in processing HCV body panels with ETP.Show how these are solved through novel thickness distribution, feed system and process design.It is highly essential to design with plastic friendly concepts and to build the tool for balanced filling, no aesthetic defects, minimum pressure and tonnage. Predictive engineering is the best tool to use at the design phase to achieve first time right.
SMC REPLACEMENT WITH ENGINEERING THERMOPLASTICS IN HEAVY COMMERCIAL VEHICLE BODY PANELS MARKET SPACE
N. Venkatesha , Claes Lindberg , Stefan Johannesson , Derek Buckmaster, May 2010
Traditionally body panels of Heavy Commercial Vehicles (HCV) are built in Sheet Molding Compound (SMC) or metal. OEMs are looking for fuel-efficient lightweight and greener technology solutions. The specific gravity of Engineering Thermoplastic (ETP) is much lower and offers significant weight reduction opportunity over SMC/metal. This paper presents limitations of SMC key challenges in terms of aesthetics and high flow length to thickness ratio in processing HCV body panels with ETP. Show how these are solved through novel thickness distribution feed system and process design. It is highly essential to design with plastic friendly concepts and to build the tool for balanced filling no aesthetic defects minimum pressure and tonnage. Predictive engineering is the best tool to use at the design phase to achieve first time right.
SOFT AND FLEXIBLE IONOMER WITH GOOD SCRATCH RESISTANCE
Agustín Torres, Joel Bohórquez, Willian Noriega, May 2010
New ionomers have been developed to afford exceptional soft feel, high flexibility, and good scratch resistance. The thermoplastic characteristics enable ease of melt processing, good adhesion to various substrates, HF weldability, and deep draw thermal forming. The new ionomer is optically clear and glossy, and can be colored and printed. It has good compatibility with various pigments and additives for enhanced esthetic effects and outdoor weatherability. The soft feel and scratch resistance, coupled with the versatile processibility, make the new ionomers well-suited for protective and decorative applications. It contains no intentionally added halogen and can be recycled or incinerated to serve as an environmentally friendly alternative to flexible PVC or a lower cost alternative to flexible TPU.
SOLVING PROBLEMS WITH BIOBASED, SUSTAINABLE PLA AND RECYCLABILITY OF PET FOR HIGH-VALUE APPLICATIONS VIA SOLID-STATE SHEAR PULVERIZATION
Audrey Durin, Rudy Valette, Bruno Vergnes, Thierry Coupez, Chantal David, May 2010
Solid-state shear pulverization (SSSP) can lead to in situ mechanochemistry and enhanced dispersion relative to melt-state processes. SSSP of poly(ethylene terephthalate) (PET) results in low levels of branching and enhanced dispersion of heterogeneous nuclei, leading to increased melt viscosity and crystallizability, providing a solution to the problem of recycling PET for high-value applications. (PET undergoes molecular weight reduction during melt processing.) Adding 1 wt% microcrystalline cellulose to poly(lactic acid) (PLA) via SSSP can lead to major enhancements in crystallizability and materials with increased heat distortion temperature relative to neat PLA.
STANDARD FOR ENERGY RATING WITH RESIN DRYERS AND CLASSIFICATION OF DRY AIR QUALITY
Sonny Morneault , Andreas Vierling, May 2010
When it comes to resin drying, energy consumption is quickly becoming a key factor in the decision making process for one technology over another. However, drying energy consumption has several elements and key factors that affect the overall energy use of a dryer. It is a combination of heat-up energy and sustainable drying energy that are the elements that will, in the end, affect how much it costs to dry your resin on an annual basis.A uniform industry test standard would define the air capacity, basic load and kWh/unit of material. An industry test standard would allow users to plug in there given material, throughput and local energy rate, to calculate the true annual energy cost.
STERILE BARRIERS FOR MEDICAL DEVICES: FAILURE MODES AND MITIGATION
Adriana Knapkova, Libor Friedel, Bruce Dehning2, Jiri G. Drobny, May 2010
From sterilization to use, medical device packaging must provide a microbial barrier for the devices they protect. Reliability of this packaging is of the utmost importance since packaging materials must endure folding, rubbing, and a host of other mechanical and environmental stresses that can challenge the barriersƒ?? integrity. Pouches consist of flashspun high-density polyethylene (FS-HDPE) sheeting and laminates films composed of polyolefins and nylons. Case studies regarding sterile pouch failures that occurred at various stages of qualification testing and solutions for mitigating failures are presented. Common failure modes and mechanisms are discussed in detail.
STRUCTURAL COMPOSITES FROM RECYCLED HDPE AND CALCIUM SULFITE CRYSTALLITES
Gediminas Markevicius , Joshua D. Stoll , Vivak M. Malhotra , Charles E. Miller , Francois B. Botha, May 2010
Typically wood-plastic composites are manufactured from HDPE and wood byproducts. However to mitigate the concerns associated with the environment and costs attempts were made to develop structural composite materials from calcium sulfite hydrate (hannebachite) natural fibers and recycled HDPE. The hannebachite crystallites are produced during the scrubbing of coal combustion flue gases and have no commercial value. The structural thermal and mechanical behaviors of the composites as well as of raw materials were determined by SEM DSC DMA and flexural measurements. Our results suggest that it may be feasible to develop wood substitute composites without the use of wood or its byproducts. Flexural strength as high as 30 MPa was obtained.
STRUCTURAL COMPOSITES FROM RECYCLED HDPE AND CALCIUM SULFITE CRYSTALLITES
Gediminas Markevicius , Joshua D. Stoll , Vivak M. Malhotra , Charles E. Miller , Francois B. Botha, May 2010
Typically wood-plastic composites are manufactured from HDPE and wood byproducts. However, to mitigate the concerns associated with the environment and costs, attempts were made to develop structural composite materials from calcium sulfite hydrate (hannebachite), natural fibers, and recycled HDPE. The hannebachite crystallites are produced during the scrubbing of coal combustion flue gases and have no commercial value. The structural, thermal, and mechanical behaviors of the composites, as well as of raw materials, were determined by SEM, DSC, DMA, and flexural measurements. Our results suggest that it may be feasible to develop wood substitute composites without the use of wood or its byproducts. Flexural strength as high as 30 MPa was obtained.
SUBSTITUTION OF POLYLACTICACID (PLA) IN PLACE OF POLYVINYLCHLORIDE (PVC) IN TRANSPARENT SIGNAGE FOR RETAIL USE
Daniel Brittingham , Nicole Larson, May 2010
This project aims to investigate the material properties of Polylactic acid (PLA) and to compare them with Polyvinyl chloride (PVC) which is currently used in retail signage. There problems inherent in changing a process from an established material to a biodegradable polymer. The mechanical properties of PLA are under scrutiny to determine if it can be a reasonable substitute for PVC a non biodegradable plastic that must be land-filled or recycled at considerable cost after its post-consumer use. Many environmentalists suggest that biodegradable plastics can be substituted to fill the same roles as conventional polymers. PLA is a biodegradable polymer that is available in grades that are transparent and are manufacturable in most common thermoplastic processing methods including extrusion. PLAƒ??s substitution for PVC in this application can help to eliminate landfill and reduce overall pollution.
SYNTHESIS AND PHYSICAL CHARACTERIZATION OF BIODEGRADABLE PLA/PHBV FOAMS
Esther Richards , Reza Rizvi , Andrew Chow , Hani Naguib, May 2010
This paper examines the effect that blending two biodegradable polymers has on the thermal properties and morphology of the resultant foams blown with carbon dioxide (CO2). Polylactic acid (PLA) Polyhydroxybutyrate-co-valerate (PHBV) and blends of both were foamed and characterized in terms of thermal characteristics relative density cell size and foam morphology. The results indicate that although PLA and PHBV are immiscible the presence of small quantities of PHBV could lead to low density foams with finer more uniform cells.
THERMAL AND RHEOLOGICAL PROPERTIES OF PHB SYNTHESIZED WITH VARIOUS HYDROXYVALERATE CONTENT FOR POTENTIAL USE IN FOOD PACKAGING
Sunny Modi , Kurt koelling , Yael Vodovotz, May 2010
PHB (Poly (3-hydroxybutyrate) families of naturally occurring polymers are extracted from micro-organisms.PHB behaves similarly to conventional thermoplastics, yet are fully biodegradable in common composting conditions.To improve flexibility for potential food packaging applications, PHB can be synthesized with various copolymers such as 3-hydroxyvalerate (HV). The objective of this study was to characterize the thermal and rheological properties of PHB synthesized with various valerate contents and relate these findings to potential food packaging applications.
THERMAL STABILIZATION OF BIODEGRADABLE POLY-HYDROXYBUTYRATE (PHB) IN MELT EXTRUSION PART 1: POLY-OLIGOMERIC-SILSESQUIOXANE
Y. Shaked , H. Dodiuk , S. Kenig , C. Schwier , S. McCarthy, May 2010
Poly-Oligomeric-Silsesquioxane POSS nano modifier was examined as a thermal stabilizer for PHB.Melt compounding of Poly-Hydroxy-Butyrate PHB copolymers with different POSS moieties was performed.Reactive and non-reactive POSS nano modifiers were used. The effect of modification on PHB thermal stability was evaluated by changes in rheology and molecular weight. POSS modifiers with unique core-shell structures were found to significantly reduce the loss in molecular weight during melt mixing possibly by decreasing viscous-heating effects.
UNSATURATED POLYESTER RESIN FROM CHEMICAL RECYCLING OF OFF-GRADE POLYETYHYLENE TEREPHTHALATE
Ali R. Zahedi, May 2010
Poly(ethylene terephthalate) [PET] from off-gradesof industrial manufacturer was depolymerised usingexcess ethylene glycol [EG] in the presence of metalacetate. Influences of the reaction time volume of EG and catalysts concentrations on the yield of theglycolysis products were investigated. In this study wehad three 3-level factors for reaction time volume ofEG and catalysts concentrations on the basis ofTaguchi's statistical method. The optimal conditionsare reaction time of 3 h molar ratio (EG to PET) of 5 weight ratio (catalyst to PET) of 0.25 wt%. Theglycolysis products were analysed for hydroxyl valueand identified by DSC and VPO. The optimum samplewas used to produce unsaturated polyester resin [UPR]by maleic anhydride [MA]. The samples alsocharacterized well by FT-IR 1HNMR and 13CNMR.
WEATHERING PERFORMANCE OF A SCRATCH RESISTANT WEATHERING PERFORMANCE OF A SCRATCH RESISTANT
T. M. Lewis, A. I. Isayev, J. Keum, May 2010
The weathering performance of a Lexan* copolycarbonate resin was studied against a benchmark PC resin. Known ISO, ASTM and SAE weathering protocols were used and observed differences explained. Lexan* copolycarbonate resin offers a scratch resistant polycarbonate solution that opens up new possibilities in terms of part performance. Key applications range from mobile phones to interior automotive trims and benefit from the elimination of secondary operations due to the increased hardness of the material. This can lead to costout opportunities and environmentally friendlier solutions where conventional protective hard coatings or painted surfaces are considered.
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