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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Conference Proceedings
β-Crystalline Polypropylene (Bepol™) and Oriented Film Applications
Sehyun Kim, Edwin B. Townsend IV, May 2002
Polypropylene with high ?-crystalline content is obtained by employing a ?-nucleator, such as ?-quinacridone, N,N’-dicyclohexyl-2,6-naphthalene dicaboxamide or a combination of a Group II metal salt or hydroxide and an organic di-acid compound. In this case, Bepol™, a ?-crystalline polypropylene, contains a small amount of a Group II metal salt or hydroxide and an organic di-acid compound. In this study, various products of Beopl™ have been characterized and applied to oriented film.
"Born" Exporting in the Mould Cluster of Marinha Grande
Leonor Sopas, May 2002
Empirical evidence on the start-up of two plastic moulds exporters located in Marinha Grande, Portugal, illustrates the process through which location within a cluster contribute to explain how start-ups manage to be born" exporters.Relations within a cluster tend to be frequent and long lasting encouraging information flows and trust. These play an important role in detecting opportunities and in accessing resources. Furthermore outward oriented clusters attract foreign buyers and facilitate unplanned contacts."
Extrusion Defects in Filled & Rubber-Modified Polypropylenes
V.G. Kolli, K. Jayaraman, September 2001
Visual observations of the surface texture of the extrudate strips obtained with a strip die are reported here for a PP homopolymer a blend of this PP with oil and a TPV produced by blending the PP/oil mixture with EPDM rubber. This was done to understand the causes of pit formation on TPV extrudates. The local packing of crystallites influenced by the degree of stretch seems to correlate with the pit formation in extruded PP/oil mixtures and TPVs.
Polyester Resin System Utilizing Renewable Sources - Soybean and Corn
T.D. Wade, September 2001
A resin that utilizes 25% grain-derived organics has been developed. Ethanol and soybean oil are reacted with other materials to produce a durable polyester resin capable of equal or better performance than current polyester resin systems. Utilizing the sheet molding compound (SMC) molding process this unique renewable-source polyester resin has successfully produced large combine parts for use in the agriculture industry. The transportation industry is investigating this resin for use on upcoming vehicles.
Development of a Structural SMC Pickup Box
D. Houston, September 2001
The Ford Explorer Sport Trac pairs the comfort and convenience of a sport utility vehicle with the added utility of a cargo bed for one-vehicle-does-it-all" versatility. The cargo bed is a combination of structural SMC for the box inner tub and Class A SMC outer body panels. As this application represents a very aggressive use of structural SMC and the first production composite pickup box in the automotive industry this paper will discuss the evaluation of structural SMC material properties pickup box laboratory component testing and on-vehicle Arizona Proving Ground (APG) durability testing."
A Molded-in-Color UV-Stable Sheet Molding Compound: One Step Beyond
P.A. Rettinger, September 2001
An ultraviolet (UV)-stable pigmentable system which is designed to be formulated into sheet molding compound (SMC) for external structural applications and which eliminates the need for paint is now available. Hailed as “the next generation of SMC” the formula meets original equipment manufacturers’ (OEMs) requirements for pickup truck box applications. The material has excellent mechanical properties and after 10000 hours of weathering the material retains its color and appearance without a need for painting.
New Preforming Method & Binder for Liquid Molding Processes
D. Buckley, September 2001
PowerPoint Presentation at ACCE 2001.
Status of Microwave Adhesive Bonding Research
S. Zhou, September 2001
Microwave adhesive bonding has resulted in significantly shorter bonding times and stronger bonds for some systems. Compared to single mode microwave adhesive bonding variable frequency mode-switching microwave adhesive bonding was applied to obtain uniform heating in microwave adhesive bonding of large-size materials. A new method was developed to monitor in situ microwave adhesive bonding of large samples. Process control programs were developed to intelligently control the microwave adhesive bonding process.
Injection Molding of Wholly Thermoplastic Composites
W. Huang, September 2001
Thermotropic liquid crystalline polymer reinforced thermoplastic polymer strands were spun and used in injection molding to form wholly thermoplastic composite materials. While keeping the strand size suitable for injection molding an effort was made to increase the orientation and aspect ratio of the reinforcing TLCP fibril. The pelletized strand was injection molded without disturbing the TLCP reinforcing fibrils. The samples have similar mechanical properties lower density and smoother surfaces compared with glass fiber reinforced samples.
Thermoplastic Sandwich Structures for Semi-Structural Automotive Parts
F. Henning, September 2001
PowerPoint Presentation at ACCE 2001.
New Instrument for Dynamic Mechanical Analysis with Controlled-Temperature Exposure to Fluids or Humidity
J.G.Van-de-Velde, September 2001
A new dynamic mechanical analyzer with special fluid bath furnace has been developed to measure the mechanical and thermal properties of materials while immersed in fluids or exposed to humidity. This technique is superior to traditional methods of first exposing the material and then performing the measurements. Such experiments are performed on several materials including oil filter paper and an epoxy coating. The former material is immersed in engine oil and shows post-curing behavior. The epoxy is measured in both air and salt water (saline). The saline experiments show that the traditional method (in air) can lead to anomalous results.
3Tex Preforms
B. Lienhart, September 2001
Topics of this paper are recent progress in 3-D orthogonal weaving composites made with 3-D woven preforms their mechanical properties and applications. The patented fabric combines no-crimp in-plane fiber reinforcement with integral through-thickness fiber reinforcement. The latter one enables to suppress delamination and substantially improve interlaminar strength and damage tolerance. 3-D orthogonal woven preforms are especially suited to composites processing using RTM technique. Also such composites are characteristic with fairly predictable basic mechanical properties allowing to apply conventional modeling and predictive analysis tools.
The Development of DFT Long-Fiber Thermoplastic Composite Soft-Top Headers
J. Busch, September 2001
In your father’s car all of the significant body structures were made from metals. Today composites are increasingly used to produce more and more demanding structures. In concept vehicles such as the Daimler- Chrysler CCV and ESX3 composites are the structure. In production vehicles pick-up boxes floor pans front-end carriers closure panels skid plates and many other structural applications are made from composites. Direct Feed Thermoplastic (DFT) composites have been used to produce several automotive structures including front-end carriers seat bases and convertible soft-top rails and headers. In this last application soft-top headers DFT composites successfully displaced steel and SRIM composites on the basis of relative cost and performance. Like most technology substitutions the process of developing the DFT header was lengthy taking over five years from concept to production. This development process along with the DFT manufacturing technology and the benefits that it imparts to soft-top headers are described in this paper. The paper demonstrates that DFT when used appropriately offers an unparalleled combination of performance aesthetic and economic benefits.
Properties of Thermoformed Low Density Glass Reinforced Thermoplastic Sheet
P.J. Bates, September 2001
The thermoformability of low-density polypropylene sheets reinforced with long discontinuous glass fibers was assessed using a laboratory scale thermoforming machine. The effects of material parameters (glass fiber loading and sheet basis weight) and processing parameters (sheet temperature and pressure) on part thickness glass fiber distribution and mechanical properties were evaluated. The results indicate that for the parts studied pressure assist is required for thermoforming. Part characteristics were observed to be reproducible and constant over a wide range of sheet temperatures and pressure assist levels. The mechanical properties of the thermoformed sheets were assessed using flexural testing. The modulus and strength values observed were comparable to properties obtained on compression molded samples of the same thickness.
Thermoplastic Composite Sandwich Panels
J. Muzzy, September 2001
Thermoplastic composites are attractive for automotive applications since they can be rapidly formed into low cost complex structures with good impact strength and flexural rigidity. The properties of these composites can be enhanced while reducing basis weight through the use of sandwich structures. This paper will illustrate the extent of enhancement achieved through the use of thermoplastic composite skins combined with lower density thermoplastic cores. Glass mat reinforced polypropylene (GMT) with a thickness of 3.8 mm and a glass content of 40 wt % will be used as a baseline for assessing the performance of sandwich panels. Skins will include GMT as well as aligned fiber reinforced laminates. Both honeycomb and foam cores will be evaluated. Flexural rigidity will be presented and impact properties will be based on instrumented drop impact testing.
The Effect of Reinforcing Fiber Length on Surface Properties of Thermoplastic Composites Made by Surface Finishing / Compression Molding
A.K. Delusky, September 2001
The Valyi SFC (surface finishing/compression) molding TM process was used to evaluate the effects of fiber length on the important performance properties required for class A thermoplastic composite panels. Class A moldings for automotive exterior use must meet demanding visual performance and demanding structural properties. The benefits of long fiber reinforcement in SFC molding have been reported. The long fiber reinforced PP resins show enhanced stiffness and impact strength. Fiber length degradation in the SFC process is minimal. This paper reports on the surface properties of polypropylene composites made with short and long fibers. Surface read through of the fiber reinforcement is examined and methods for improvement are discussed. The SFC process combines resin extrusion film finishing and compression molding in one low pressure molding process. In this process a finishing film is placed over a mold cavity resin is extruded over the film from a traversing “coat-hanger” die and the mold is closed to form and finish the part in one step. This process has been successfully used to mold full-scale vertical and horizontal panel composites.
Stamping of Woven Fabric Reinforced Thermoplastic Composites
W.R. Yu, September 2001
This study is to investigate the feasibility of shaping preconsolidated woven fabric reinforced thermoplastics using sheet hydroforming as being a new forming method for composite manufacturing. For that purpose a new constitutive model has been developed based on a homogenization method considering the microstructures of composites including mechanical and structural properties of fabric reinforcement. The current model aims to account for the effect of the fiber strength difference and orientation on anisotropy and also to simulate shear deformation with no length change which is common in FRT composite forming. For validation purposes the developed model was implemented in an explicit dynamic finite element code and tested for several deformation modes including pure shear as well as three-dimensional deformation mode
Bio-Composite Materials as Alternatives to Petroleum-Based Composites for Automotive Applications
L.T. Drzal, September 2001
Natural/Bio-fiber composites (Bio-Composites) are emerging as a viable alternative to glass fiber reinforced composites especially in automotive applications. Natural fibers which traditionally were used as fillers for thermosets are now becoming one of the fastest growing performance additives for thermoplastics. Advantages of natural fibers over man-made glass fiber are: low cost low density competitive specific mechanical properties reduced energy consumption carbon dioxide sequesterization and biodegradability. Natural fibers offer a possibility to developing countries to use their own natural resources in their composite processing industries. The combination of bio-fibers like Kenaf Hemp Flax Jute Henequen Pineapple leaf fiber and Sisal with polymer matrices from both non-renewable and renewable resources to produce composite materials that are competitive with synthetic composites requires special attention i.e. biofiber- matrix interface and novel processing. Natural fiber reinforced polypropylene (PP) composites have attained commercial attraction in automotive industries. Needle punching techniques as well as extrusion followed by injection molding for natural fiber–PP composites as presently adopted in the industry need a “greener” technology-- powder impregnation technology. Natural fiber–PP or natural fiber–polyester composites are not sufficiently eco-friendly due to the petro-based source as well as non-biodegradable nature of the polymer matrix. Sustainability industrial ecology eco-efficiency and green chemistry are forcing the automotive industry to seek alternative more Eco-friendly materials for automotive interior applications. Using natural fibers with polymers (plastics) based on renewable resources will allow many environmental issues to be solved. By embedding bio-fibers with renewable resource based bio-polymers such as cellulosic plastic corn-based plastic starch plastic and soy-based plastic are continuously being developed at Michigan S
Approaches to Clay Nanolayer Reinforced Thermoset Epoxy Polymer Nanocomposites
C.S. Triantafillidis, September 2001
Montmorillonite clay - diamine intercalates were used for the formation of glassy thermoset epoxy – clay nanocomposites. The intercalated alpha-omega polyoxypropylene diamines (Jeffamines) played the dual role of organic modifier and curing agent. Depending on the chain length the intercalated diamines adopt different configurations inside the clay galleries resulting in basal spacings from ~14 Å (lateral monolayer) to ~45 Å (folded structure). Accordingly non-intercalated and exfoliated (nano)composites were formed with improved mechanical properties. From a mechanistic point of view they offer the optimum environment for enhanced intragallery polymerization by eliminating the effect of dangling alkyl chains in the polymer’s matrix and by utilizing the catalytic activity of both onium ions of each diamine molecule. The use of the primary diamines as organic modifiers of the H+-clays afford an in situ functionalization of the inorganic clay as part of the curing process of thermoset epoxy polymers reducing the cost and time for nanocomposite fabrication.
Increasing the Impact Resistance of Short Glass Fiber Reinforced Vinyl Composites
M.E. Woods, September 2001
The addition of short glass fibers to thermoplastic materials is known to significantly reduce the impact properties of the resulting composites. This paper is the third in a series devoted to understanding and improving the impact strength of short glass fiber reinforced vinyl composites. The first paper characterized the impact behavior and failure mechanisms of these materials. The second paper examined methods of increasing the impact resistance using semi-rigid capstock laminates. The current paper extends this work to laminates using rigid vinyl layers to achieve higher impact strength. Instrumented drop weight impact results demonstrate improvements up to four times that of the original composite.
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