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The construction of most automotive interior headliners requires an adhesive material to bond polyurethane foam-backed fabric to a molded headliner shell. More than ten years ago, The Dow Chemical Company qualified and began supplying a thermoplastic adhesive polymer film for headliner applications which replaced wet adhesive systems at several fabricators. DAF 899 adhesive film has gained acceptance in the industry due to excellent performance, convenience, and cost effectiveness without additional waste handling or volatile organic emission concerns. Recent advancements in headliner design such as additional recessed areas with more demanding contours, new substrate materials and the desire for more efficient operations created an opportunity to design improved adhesive films to meet the emerging industry demands.

Thermoplastic polyurethane/ABS blends are being developed by The Dow Chemical Company to meet the high performance requirements for flexible bumper fascia. Features of these blends include paintability without priming, excellent low temperature impact after painting, good heat resistance, and lower specific gravity than other high performance thermoplastic materials. Thermoplastic polyurethane/ABS blends also have excellent flow properties, which will allow large, complex parts with thin walls to be molded easily.

Adhesive materials are required to bond cover fabrics to most molded interior headliner substrates. Several thermoplastic adhesive films are qualified and used at U.S. and Japanese OEM's. These adhesive films offer benefits such as convenience, cost effectiveness, excellent adhesive performance and process efficiency while reducing concerns of emissions and hazardous waste handling compared to prior bonding methods. The automotive headliner part is a multifunctional component of the vehicle's interior trim. One of the main headliner functions is to reduce the interior cabin noise. Various adhesive materials are used in a lamination process to form a composite headliner. The purpose of this study was to compare the effects of this lamination process and various alternative adhesive materials on the overall acoustical performance of the headliner composite. Various headliner samples were fabricated under controlled process conditions and tested by an independent acoustics testing lab.

Continued development of Reinforced Reaction Injection Molding (RRIM) polyurea polymers for toughness, blister resistance and large-part processing as exterior vertical body panels has launched ELPO-compatible exterior outers into automotive assembly-line operations. This allows automotive OEM design to take advantage of the unique molding shapes for side outers and fenders while reducing weight, assembly (DFA) and time/operations costs (DFM). Polyurea RRIM body panels have been successful in meeting the demanding auto industry requirement for lightweight, damage-resistant exterior outer panels as an economical alternative to steel. Design freedom advantages, low prototype cost and tooling savings through predictive modelling have allowed the commercial use of RRIM body panels. This high-temperature-resistant polyurea RRIM composite allows on-line painting, including passing through the steel corrosion protection primer (E-coat) cure environments.

Syndiotactic potystyrene (SPS) is a new semi-crystalline polymer under development by Dow Plastics, a business group of The Dow Chemical Company. The material is differentiated from conventional styrenic polymers in terms of microstructure and physical properties and represents the basis for an entirely new family of materials derived from crystalline polystyrene. SPS exhibits excellent thermal performance with a melting point of 270° C (520° F) combined with resistance to moisture and automotive fluids. Products produced from SPS demonstrate exceptional electrical performance, low specific gravity, competitive toughness and high modulus relative to other semi-crystalline engineering polymers. A wide range of products have been formulated including impact modified and glass reinforced resins for use in specific markets.

The objective of this paper will be to review a novel recycle process involving Structural Reaction Injection Molding(SRIM) which enables a variety of coarsely ground plastic recycle materials to be incorporated into the molded part. What makes this approach novel, is that flexural modulus of the fabricated parts are actually increased when the recycled granulate is employed in the part. This paper will present data for the recycle of a variety of automotive parts, including painted fascia, door skins, covered interior door panels, armrests and instrument panels along with composite bumper beams into the SRIM recycle core process. Resulting part economics will be reviewed along with potential applications to utilize this technology.

The use of low density reinforced Reaction Injection Molded (RIM) substrates for covered interior automotive articles continues to increase globally. Reduced party mass, consolidation of manufacturing steps (labor), and the use of aluminum tooling, instead of steel, are cited advantages that LD-RIM offers when compared to traditional wood based and thermoplastic materials. Two RIM processes are successfully being used to produce covered interior door panels. Low density structural RIM (LD-SRIM), utilizing conventional RIM equipment, involves the placement of a pre-cut fiberglass mat in the tool cavity prior to open-pour injection of the 2-stream liquid urethane components. Low density reinforced RIM (LD-RRIM), utilizing lance cylinder RIM equipment, incorporates reinforcing fibers, such as milled fiberglass or wollastonite, in the liquid resin component. The liquid resin containing reinforcing filler is injected with the isocyanate component into a closed mold.

The opportunity for composites in engine closure systems such as valve covers, oil pans, and timing belt covers is expanding rapidly. The primary driving forces are lighter weight finished components, integrated designs, improved isolation of engine noise, improved materials systems, and matured manufacturing processes for composite materials. Thermoset-based composite materials, particularly those based on high-temperature resistant epoxy vinyl ester matrices, offer improved performance with respect to thermoplastic and thermoset polyester-based composites and can be manufactured using different processing methods. This paper presents the current state-of-the-art design, engineering and optimization techniques for engine closure systems. The performance requirements of different systems such as valve covers and oil pans are explained in detail. Techniques for long-term structural stiffness evaluation, vibration performance assessment and noise transmission estimation are described.

Syndiotactic Polystyrene (SPS) is a new semi-crystalline polymer under development by Dow Plastics. The material is completely different from conventional styrenics in structure, physical properties and synthetic method, and represents the basis for an entirely new family of materials based on crystalline polystyrene. SPS has a melting point of 270°C (520°F) combined with excellent resistance to moisture and automotive fluids. Additionally, SPS products exhibit exceptional electrical performance and competitive toughness and stiffness. A wide range of products have been formulated for specific applications including impact-modified and glass-reinforced grades. This paper was designed to discuss the performance attributes of SPS as they relate to use of this material in automotive, interconnect systems where a combination of heat resistance, chemical resistance, dimensional stability and enhanced processability are required.

Relative advantages and disadvantages of blow molding vs. injection molding as they pertain to the production of automotive instrument panels are compared. Specific design issues such as parts consolidation and surface appearance are discussed, along with such processing issues as cycle time, tooling costs and regrind generation. In addition, an economic model is presented which examines the sensitivity of part cost to such variables as capital required, tooling cost, cycle time, finishing costs, regrind generated, and yearly volume of parts produced. The result is both a qualitative as well as quantitative tool to aid the designer and manufacturing engineer in making a rational process selection.

A new family of high heat stable, few gloss ABS resins has been developed specifically to offer the automotive industry improved performance in molded interior trim parts. The new resins offer excellent fabrication and property performance similar to that of standard-heat low gloss ABS resins. Advantages over current high heat ABS resins include improved injection moldability, greater resistance to heat warping and to U.V. degradation, improved color stability, improved toughness, and consequent good finished part economics while maintaining equivalent heat resistance. Physical property and testing-evaluation data are provided.