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

Various topics related to sustainability in plastics, including bio-related, environmental issues, green, recycling, renewal, re-use and sustainability.

PROCESSING COSTS AND ENVIRONMENTAL IMPACT OF BIO-PLASTICS

Julius Vogel , Dr. David Grewell , Rob Anex, May 2010

This work studied bio-plastics such as polylactic acid (PLA) and protein based plastics form corn and compared to petroleum based plastics such polyethylene (PE) and polystyrene in terms of their ecological as well as economical performance from a 'Cradle to Grave' perspective. This study included energy input, emissions output of green house gases and costs from their life cycle steps of raw material acquisition to the final product disposal. It was found that products manufactured from bio-based feedstocks were relatively higher in cost, they resulted in less green house gas emissions.

PROPYLENE BLOCK COPOLYMER AS A COMPATIBILIZER FOR POST CONSUMER HDPE/PP BLENDS

Nora Catalina Restrepo Zapata, Juan Manuel Vélez Restrepo, May 2010

Melt compounded polymer blends such as PP/HDPE blends from post consumer waste have often been reported to exhibit poor mechanical properties. This work reports on the potential improvement in performance of PP/HDPE blends using polypropylene copolymers as compatibilizers. The properties of the PP/HDPE blends in general progressively varied from that of 100% HDPE to 100% PP. Analysis showed some improvements in mechanical performance of the blends with the addition of PP copolymers, but DMTA results suggest no improvement in compatibility.

RELATIONSHIP BETWEEN PROPERTIES, CITRATE CONTENT AND POSTPRODUCTION TIME FOR A PLASTICIZED POLYLACTIC ACID

Jungjoo Lee, Lih-Sheng Turng, May 2010

Due to the recent interest on citrates as a biodegradable plasticizer for Polylactic acid PLA, several PLA blends that were plasticized with tributyl citrate TBC were prepared in a co-rotating twin screw extruder. A range of 12.4 to 22.5% by weight was considered for the plasticizer content. The thermal, rheological and mechanical properties were correlated with the plasticizer content and compared with pure Polylactic acid. Additionally, the change of these properties as a function of postproduction time was studied and correlated with the plasticizer permanence.

RESEARCH ON DYNAMIC INJECTION MOLDING FOR METAL POWDER GREEN PART

Liu Bin , Liu Qinghui , Feng Yanhong , Qu Jinping, May 2010

A new injection molding for metal powder green part was put forward in detail in this paper. Vibration force field generated by electromagnetic field in the whole process of plasticization, injection and packing, implementing dynamical plasticization metering, injection and packing was introduced. An in-depth experiment study on the effect of vibration force field on metal powder 316L/binder under steady and dynamic injection conditions was carried out with an experiment equipment and dynamic injection machine. Experimental results show that the filling pressure will be reduced when the vibration is introduced, the flow of melts becomes more uniform and the distribution of different components is also more uniform in the green parts during the dynamic injection molding. The mixing dispersion and distribution effect are better and the density is also larger than the green part's with traditional injection molding. The existing of vibration can effectively promote not only the microcosmic structure and also quality of metal powder green part.

RESIN LIFE CYCLE ESTIMATION TO HELP GUIDE SUSTAINABILITY CHOICES

Carol M. Casarino , Barry A. Morris , Susanne R. Veith, May 2010

Life cycle analysis (LCA) is an accepted methodology to determine the environmental impact of a certain material or package at different stages in its product life. In some cases, however, LCAs can be complex and expensive to carry out. DuPont is looking at ways to internally estimate the LCA of its products by using a modular approach: building estimates of nonrenewable energy and green house gas emissions by summing proprietary information on our ingredients and unit operations. The output of this tool will be used to target our internal improvement efforts and potentially help our value chain partners make better multilayer flexible packaging design choices.

RESIN LIFE CYCLE ESTIMATION TO HELP GUIDE SUSTAINABILITY CHOICES

Carol M. Casarino , Barry A. Morris , Susanne R. Veith, May 2010

Life cycle analysis (LCA) is an accepted methodology to determine the environmental impact of a certain material or package at different stages in its product life. In some cases however LCAs can be complex and expensive to carry out. DuPont is looking at ways to internally estimate the LCA of its products by using a modular approach: building estimates of nonrenewable energy and green house gas emissions by summing proprietary information on our ingredients and unit operations. The output of this tool will be used to target our internal improvement efforts and potentially help our value chain partners make better multilayer flexible packaging design choices.

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.