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The recycling of plastics from end of useful life durable goods continues to evolve as an issue. Recycle strategies need to be based on a careful understanding of sustainability for both the environmental and business domains. The definitions and processes utilized in a recycle program can dramatically affect the economic structure. These recycle programs need to be carefully constructed to minimize cash costs. There is an emerging industry, recyclers, who may become an important link in the recycle supply chain.

The American public's desire to recycle and the predictions of future recycle mandates are motivating automotive OEMs and plastic suppliers to address the recycling of plastic materials. As a result, the OEMs and plastic industry groups have asked resin suppliers, automotive dismantlers and reprocessors to assist them in studying and developing solutions for the recovery of post-consumer automotive plastics and recycling those materials back into automotive applications. The Dow Chemical Company has been a participant in plastic industry sponsored projects and has initiated numerous research and development activities involving the recycling of automotive thermoplastic and thermoset materials, as well.

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.

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.

Environmental regulations, energy conservation considerations, and consumer pressures have influenced significant changes in automotive design. Some of these changes have created environments that are particularly detrimental to elastomers. A specific example of this is the automotive underhood environment. Due to “downsizing”, front wheel drive and better aerodynamics, the already harsh environment of fuels, oils and chemicals has been accelerated by increased underhood temperatures. These increased temperatures have pushed many commonly used elastomers to their limit. This paper discusses the attributes of chlorinated polyethylene elastomers and how they fit into the increasingly demanding automotive underhood environment.

Cushioning and load distribution performance of plastic foams was investigated, using a human faceform as the loading object. A technique for measuring contact surface between faceform and plastic foam was developed. Transferrable paint applied to the foam facilitated determination of average stress over its surface, which in turn was employed to evaluate load distribution properties of the foam. Impact and static testing results on several plastic foams were analyzed. It was found that a good cushioning material characterized by low peak deceleration might show high average stress, thus making it an inefficient load distributor. The faceform used in the study incorporates the effect of face geometry during loading and thus provides a realistic simulation. Variation of material response with loading geometry and possible correlation between load distributing properties and rigidity of the foam are also discussed.

Today's interior systems design engineer has been challenged with providing significantly lighter, simpler and more cost-effective instrument panel (IP) design solutions, while simultaneously meeting rigorous occupant protection and quality standards. These issues provided the motivation behind the fully-integrated structural instrument panel design developed for Chrysler's Dodge Dakota Truck Platform. This total system design approach greatly depends on the stiffness and ductility of the engineering thermoplastic substrate and cross-sectional design for managing the energy of unrestrained occupants during frontal collisions. The structural IP consists of a fully integrated, three-piece monocoque thermoplastic structure that replaces the traditional retainer, air delivery ducts, steel beams and reinforcements typically used in IP designs.

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.

New efforts to improve quality control through the use of Statistical Quality Control techniques were introduced to the Dow Magnesium Extraction Process. All the employees in the magnesium plants were trained in the Statistical Quality Control procedures. Successful application has lead to improved chemical purity and reduced variability in the feed process. These improvements were followed by better reduction cell operation, improvements in alloying and casting operations. Consistent quality, high purity magnesium alloys are now available for use in automotive applications.

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.

A fully-integrated thermoplastic structural instrument panel (IP) system will be implemented on Chrysler's Dodge Dakota Truck Platform. The structural IP consists of a three-piece monocoque thermoplastic injection molded structure that replaces the traditional retainer, air delivery ducts, steel beams and reinforcements typically used in IP designs. Ribbed thermoplastic bolster systems have been incorporated as part of the energy management system. The structural IP provides the required stiffness to satisfy noise, vibration, and harshness (NVH) quality targets and the necessary strength and rigidity to effectively meet FMVSS No. 208 requirements for managing occupant and passenger air bag (PAB) deployment loading during 48 km/h (30 mph) frontal crashes.

Material and design engineers are constantly faced with the task of selecting the best thermoplastic material for interior trim applications. The purpose of this paper is to relate the results of physical property testing and part evaluation to their plastics selection process to allow a more optimized material choice for automotive interior applications. The thermoplastics that were evaluated in this study are the two largest volume plastics used today in interior trim, ABS (acrylonitrile, butadiene, styrene terpolymer) and polypropylene.

A method for refining magnesium scrap which produces consistent, high quality magnesium metal has been developed. High quality magnesium metal is defined in this paper as metal which has heavy metal contaminants controlled within high-purity ASTM chemical specification, and is relatively free of internal impurities such as non-metallic inclusions (oxides and flux) and dissolved gas. The refining process utilizes a protective gas atmosphere, inert gas sparging and filtration techniques, rather than salt based fluxes, to remove both non-metallic inclusions and dissolved gases. Experimentation results of this refining process indicate magnesium scrap can be remelted and refined to a quality equal to or better than virgin ingot, without the introduction of salt based fluxes or a large capital investment.

Structural instrument panels are an excellent alternative to traditional constructions since they can provide substantial part consolidation, weight reduction, tool and cost savings, and manufacturing and assembly simplification. In structural panels, the main energy absorbing element for decelerating an unrestrained occupant is the plastic integrated retainer-structural duct. The role of the components in the instrument panel needs to be clearly understood for adequately engineering the system and properly selecting the polymeric material for optimum system performance in the different operating environments. The present paper discusses the performance of the structural instrument panel, the engineering and design requirements, and provides guidelines for selection of materials.

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.

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.

Novel acoustical materials have been developed. The materials are thermoplastic foams extruded from blends of a polypropylene (PP) resin with an ethylenic polymer resin. One material is an open-cell sheet product made from a blend of a PP resin and a polyolefin elastomer (POE). Another is a large-celled plank foam of substantially closed-cell structure made from a blend of a polypropylene resin and a low density polyethylene (PE) resin. The foam materials are of lightweight, hydrophobic, dust free, recyclable and withstand the temperatures prevailing in automotive uses.

In 1998, approximately 57,000 Tonnes of plastic composites were utilized as body panels on cars and trucks in North America. Three material types, generically labeled SMC, RIM and Thermoplastic are vying to carve a market niche from steel which dominates the market place with an estimated volume of 1 million Tonnes per year. Since plastic body panels have higher material costs but lower tooling costs, they are primarily utilized when build volumes are less than 200,000 vehicles per year or specific composite performance capabilities are demanded. This paper reviews the various performance parameters required of a body panel material and the relative strengths of Aluminum, RIM, SMC, Steel and Thermoplastics to meet these demands. A decision making process is utilized which allows for a comparison between the different materials. Since cost is so critical, it is left as an independent variable.

A highly reflective polymeric sheet has been invented which has a metallic appearance but contains no metal. The material can appear chrome-like, or be designed to transmit and reflect light for novel lens applications. The absence of metal waste streams and volatile organic emissions gives this technology significant environmental advantages over competitive methods of bright work or reflector fabrication. This unique optical material is non-corroding, and has the low thermal and electrical conductance of plastic. It is produced by coextruding a large number of alternating layers of polymers having a refractive index difference. This technology offers new degrees of freedom for light control in many applications including lighting reflectors, lenses, display panels, decorative trims, and energy management.