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Sheet molding compound (SMC) is widely used in automotive parts appliances furniture and construction. These materials heavily depend on the petroleum supply which is depleting fast. The use of plant oils as an alternative source for SMC resins presents economic and environmental advantages over petroleum. Two synthetic methods have been used to develop new resins from triglycerides. The double bonds presented on the fatty acid chains were first converted to epoxy or hydroxyl functionality; the hydroxyl groups were maleinized while the epoxies were acrylated and then further maleinized. When these functionalized oils were combined with 33.3 wt% styrene the polymers showed mechanical properties comparable to those of commercial unsaturated polyesters. In addition these new resins exhibit adequate thermo-reversible thickening behavior with MgO. These triglyceride-based resins have good compatibility with natural fibers such as hemp and flax to form low-cost green composites. New bio-based nanocomposites were also developed using these new resins and organo-treated clays and the nanocomposites showed considerable increase in modulus and toughness. These new green materials show the promise to be used in the automotive industry.
Hwan-Man Park, Manjusri Misra, Amar K. Mohanty, Lawrence T. Drzal, September 2004
Sustainable nanocomposites have been successfully fabricated from renewable cellulose acetate (CA) environmentally benign triethyl citrate (TEC) plasticizer and organically modified clay. The effects of processing conditions such as mixing methods pre-plasticizing times retention times (RT) and addition of compatibilizer maleic anhydride grafted cellulose acetate butyrate (CAB-g-MA) on the performance of these nanocomposites have been evaluated. The cellulosic plastic with CA/TEC (80/20 or 75/25 wt. %) was used as the polymer matrix for
nanocomposite fabrication. The morphologies of these nanocomposites were evaluated through X-ray diffraction (XRD) Atomic force microscope (AFM) and transmission electron microscopy (TEM) studies. From all the sequential mixing methods used powder-powder mixing leads to the most transparent nanocomposites. Cellulosic plastic-based nanocomposites obtained using increased pre-plasticizing times and RT showed better-exfoliated structures. Cellulosic plastic-based nanocomposites with 5 wt.% compatibilizer contents showed better-exfoliated structure than the counterpart having 0 or 7.5 wt.% compatibilizer contents. Polygonal shape of exfoliated clay platelets was observed with 500 nm width and 800 nm length by AFM and TEM imaging. The mechanical properties of the nanocomposites have been correlated with the XRD and TEM observations.
Equal channel angular extrusion creates novel properties in metal and polymer materials.
Recently the authors investigated the effects of this process on commercial short fiber
composites. Experiments show that ECAE provides a means for controlling fiber length and
orientation in the extrudate. The process might transform continuous fiber thermoplastic matrix
composite sheets into high volume fraction discontinuous fiber sheet for thermoforming. In
addition the process might provide a method of recycling reground components into high-value
sheets with a known fiber orientation.
Merry Lo, Suhara Panthapulakkal, Mohini Sain, September 2004
This research work aims to replace glass fibres in sheet molding compounds (SMC) by renewable natural fibres. These eco-efficient and cost effective SMC with natural fibres are gaining much attention in the automotive industry because of their specific properties. The specific objective of the work was to develop a high performance natural fibre hybrid SMC to meet the specifications required for automotive parts such as front fenders body panels etc. Hemp fibres with and without a combination of a small amount of glass fibres were used to reinforce vinyl ester resin for making SMC. Different combinations of layers of hemp and glass fibres were made to prepare SMC. Mechanical properties such as tensile and flexural properties and impact strength of the SMC prepared were found to be highly promising. The current OEM specifications for automotive parts for example rare lift gate and front fenders recommend the composite should have tensile strength of 62 MPa and tensile modulus of 2 GPa (Source of Automotive Engineers Car Technology yearbook 2000” USA 2000 Body panels Properties). SMC prepared by the combination of 45% of hemp fibres and 5% of glass fibres showed tensile strength and modulus were more or less same or better than that of the requirements for car body parts such as rare lift gate and front fenders (Tensile strength greater than 62 MPa and tensile modulus of 2 GPa).Use of this SMC with natural fibre is an economically viable alternative to SMC with glass fibres and at the same time it helps
reducing the green house gas emission as there is lesser amount of synthetic resins and plastics.
Most people are aware of what natural fibers are but few know of the diverse capability of this natural resource and unfortunately industry pressures over the past several years to reduce costs focused on trying to refine well established technologies using glass or wood fibers or to a certain extent injected molded polymers. It has only been through recent pressure by some of the larger OEM’s that natural fibers have been gaining broader interest for both their performance and environmental benefits as compared to older more comfortable based technologies.
Cost versus performance is a delicate balancing act. Fortunately natural fibers go a long way on striking a balance between both of these most common demands. When considering performance natural fibers offer an unlimited range of lighter weight possibilities for interior and exterior applications. Most common today natural fibers are commingled into a nonwoven mat with fiberized thermo plastic polymers such as polypropylene and polyester for use in common interior applications that include door panels center consoles pillars and inserts. However advancements in the range of available natural fibers and specialty polymers along with a continuous improvement of the nonwoven process are now providing for greater heat stability to meet the elevated requirements for over head systems package trays and topper pads.
Increased demands for occupant safety give further reason to consider natural fibers as few other materials provide the same impact characteristics with the base material. For exterior applications natural fiber mats used as the base material in sheet molding compounds will find their way into bumper reinforcements wheel well liners and under hood applications. The industry historically focused on direct material cost. In this simplified approach natural fibers seldom will come out to be the low cost alternative but when considering the benefits
derived from one-step processing the end cost of the finis
Yi-Fan Wu, Yio-Chih Kao, Ru-Shiamg Kung, Hsiau-Fu Shen, May 2004
Torque, time, and temperature were simply applied to monitor the dynamic esterification of degradable starch-based polymers reacted by different types of acids and catalyst. The formation of C=O double bond and C-O single bond at the region of around 1710cm-1 and 1250cm-1 respectively denotes some successful consequence. SEM was furthermore applied to check the compatibility between modified starch and polymer while TGA for the check of starch before and after modification.
Christopher C. Ibeh, Dhirendra Bhattarai, Mark Schultz, May 2004
A prior advanced materials selection process via the digital logic approach (DLA) yielded five materials as suitable choices for the housing of the Signal Detector Control Head Unit (SDCHU), with ABS (acrylonitrile-butadiene-styrene) terpolymer and aluminum 1100 as the top two choices. In an effort to study the long term perspective, durability and environmental impact of the SDCHU, a life cycle value analysis (LCVA) was performed on the SDCHU with ABS as the housing material and then with aluminum 1100 as the housing material. The LCVA results indicate that ABS is the choice material in seven of the eight impact categories studied such as costs, energy usage, conventional pollutants, green house gases released, fuels used, ores used, hazardous waste generated and water used. Normalized environmental impact data show that the 5.6% increase in hazardous waste is offset by the 8 - 52% reduction in the other seven categories due to ABS use in the SDCHU housing.
A.S. Ditta, A.J. Wilkinson, G.M. McNally, W.R. Murphy, May 2004
This study focuses on the ability of U-PVC to be processed a number of times. Three different types of U-PVC were investigated: virgin lead stabilised and virgin calcium/zinc stabilised material and reground, 20 year old, post-consumer windows. Each material was extruded four times and samples taken at each stage for rheological and mechanical analysis.
Foamed products based on renewable raw material have a high application potential e.g. for packaging because of their biodegradeability. This may permit renewable raw materials to substitute polymers like polystyrene in some applications.A common way to process renewable raw material like starch is to produce starch based resins with twin screw extruders. These resins can be used on conventional polymer processing machines, but the step of compounding the starch on twin screw extruders causes costs which make these resins economically unattractive.Due to a new extrusion technology these costs can be reduced by a direct processing of starchy material like maize. A characteristic of this extruder is a very short (2 L/D), conic, multiple flighted screw in a barrel with spiral grooves. The energy for the plasticizing process is yielded just by the transfer of mechanical energy of the rotating screw into friction in a shear gap between screw and barrel.In order to understand the process different geometries of screw and barrel have been used in the experiments, additionally the process parameters have been varied. The results lead to an optimised configuration of the extruder and to a better understanding of the influence of process parameters on the product properties.
This paper presents an investigation on the strategies to increase the post consumer HDPE recycling of extrusion blow molded oil containers in Australia and proposes a novel oil drain rack designed to drain out the residual oil effectively from the used oil containers, based on the requirements of the clients.
The manufacturing of Plastic Fuel Systems is an ever changing and technology driven field. The field is influenced by governmental emission standards that are becoming tougher to meet with plastic fuel tanks. Several new technologies have been developed to accommodate the environmental legislative changes.
The Stress Corrosion Cracking (also called Environmental Stress Cracking) process in Polybutylene (PB) tubing consists of three stages: 1) Crack initiation, 2) Slow crack growth, and 3) Dynamic crack propagation. The first two stages primarily determine the useful lifetime of PB tubing, since the third stage occurs in a relatively short time interval. In this paper, an examination of PB field failures, observation of crack initiation mechanisms, and evidences of chemical degradation as a primary cause of failure are presented. To evaluate crack initiation time in mechno-chemical conditions, a modification of ASTM standard environmental stress cracking technique is employed to accelerate the crack initiation process in PB and a simple extrapolation technique is proposed to estimate the time of crack initiation in service conditions.
Filled thermoplastic polyetherimide and polystyrene samples were prepared and their morphological and melt processing properties were studied with respect to the processing conditions and filler loadings. The results should provide insights that are needed to solve complex issues encountered in the industry dealing with the recycling and processing of this important class of thermoplastic materials.
Coatings or paints are generally pigmented polymeric dispersions or powders that are usually applied as a secondary process step to form a layer on the substrate. Eliminating coatings can drastically reduce the cost of the part as well as provide environmental advantages. In recent years there have been major advances in alternatives to coatings for automotive plastic parts. These advances are categorized into two main areas, material development and process development. From a materials perspective, new colorants and modifiers have been developed as additives to plastic resins that provide the aesthetic and physical and chemical properties required. From a process perspective, advances in process technology in areas of extrusion, co extrusion, injection molding, laminating films, and thermoforming of multiplayer sheets have been developed. This paper will examine these different alternatives to coatings for automotive plastic applications.
John Muzzy, Youjiang Wang, Melinda Satcher, Bryan Shaw, Andrew McNamara, Josh Norton, May 2004
Over 2 million tons of post-consumer carpet is landfilled each year. This waste carpet is a potential resource for composites. Since waste carpets can be rapidly identified and sorted by face fiber, this paper focuses on the processing and properties of nylon 6 post-consumer carpet. The carpet is cleaned, shredded and extrusion pelletized. This feedstock is compounded with glass fibers and compatibilizers. Based on the properties achieved and the projected costs, applications are identified.
Sayata Ghose, A.I. Isayev, Ernst D. von Meerwall, May 2004
A continuous process for decrosslinking high resiliency polyurethane foam in an extruder with ultrasonic devices was developed. Rheological, structural and NMR relaxation and diffusion characterizations of decrosslinked foam were performed. The decrosslinked foam was blended with the virgin polyurethane rubber (PUR) and cured and the blend properties were investigated.
Injection molded bars have been made from blends containing recycled photodegraded polymers, then subjected to further ultraviolet (UV) exposure. Crystallinity measurements have been made at different depths from the exposed surface using X-ray diffraction and differential scanning calorimetry. Complementary information in the form of molecular mass distributions has been obtained using gel permeation chromatography, and the crystallinity results are interpreted in terms of molecular scission and photo-initiated molecular defects.
In recent years, pressure from economic and environmental requirements has been experienced in the field of polymer production. This trend towards single stage operational units, in processes such as low shear devolatilization of elastomer solutions, radical polymerization and polycondensation reactions, phase changing processes and the conversion from batch to continuous operation continues and has lead to the development of large volume, twin shaft horizontal processors (LVPs).These processors have been designed for applications requiring medium to long residence times (20-120 minutes).As an example of this new family of processors, the multi-purpose Reasol®, a new counter-rotating twin shaft processor, is introduced. Trials with model polymers have been performed in a 60L unit at the developer's test center. Its performance is described here by power consumption, RTD (residence time distribution) and self-cleaning and devolatilization efficiency.Trials show that product transport through the new LVP is characterized by a narrow RTD with a high degree of self-cleaning. Typically, the RTD exhibits a Peclet number in the region of 25-35. It is also shown that, unlike typical twin-screw extruders, the shape of the RTD curve is largely unaffected by the rotor speed or mass rate. Furthermore, rotor speed has a relatively small effect on mean residence time thus allowing the freedom to optimize rotor speed with respect to other processing objectives such as heat transfer, surface renewal or shear rate.The indications are that the characteristics of the RTD, power consumption and devolatilization are analogous to more traditional equipment such as twin screw extruders in spite of the larger free volume and residence time and the lower shear.The new LVP is commercially available up to sizes of 12,500 litres net processing volumes.
In this work, an extrusion process has been developed for the devulcanization of rubber crumb from recycled tires employing supercritical CO2. For that purpose supercritical CO2 has been injected in a twin screw extruder to swell the rubber crumb and to facilitate the otherwise impossible rubber extrusion process. As a consequence, waste rubber can be processed under mechanical shear and extensional forces at various operating conditions that may lead to different degrees of devulcanization.
José B. Sánchez, Erika Galvis, Rosalina Grimaud, Rosestela Perera, May 2004
This work presents the effects of incorporating post-consumer and post-industrial recycled HDPE to their virgin counterparts and to LDPE in different contents to produce tubular film for packaging. Tensile, surface and optical properties for each blend were measured.A reduction in the HDPEs blends physical properties and an increment in those of the LDPE/recycled HDPE blends were obtained as the recycled HDPE component was increased.
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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
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.