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Creativity and economy.

CREATIVITY AND ECONOMY

Plastics continue to respond to the changing needs of the automotive industry. The 1990 models, and those on the drawing boards, reflect the growing tendency of management and designers to look to plastics for economical, creative car designs. Steady advances in materials and productivity, and the many proven applications, have shown that increased plastics usage can be a major route to meeting diverse industry goals.

FENDER FIELD TEST

Chrysler Motors will evaluate more than 400 Dodge Caravan CV minivans fitted with reinforced thermoplastic front fenders. An 18-month field test with a major fleet customer, Xerox Corp., could be a prelude to high-volume production, perhaps in the early 1990s. In vehicles shipped nationwide to more than 25 Xerox service facilities, the program will check fender durability in varied geographies, climates, and traffic.

Molded of polyethylene terephthalate (PET) supplied by Du Pont and reinforced with glass flake and fiber, the fenders have withstood the high-temperature E-coat paint bake cycles that steel body parts on Chrysler minivans routinely endure during manufacturing.

In another application, the first such use of the technology in the U.S. auto industry, selected 1990 models--the Chrysler Le Baron coupe, convertible, and sedan; Dodge Daytona, Spirit, and Shadow; and Plymouth Acclaim and Sundance--will be equipped with 5-mph bumpers with self-restoring elastomeric energy-absorbing units.

The Du Pont Hytrel unit, a molded hollow cylinder that surrounds the bumper system's sliding central member, is more versatile, simpler, and lighter than hydraulic designs. When the bumper is struck, the cylinder compresses and buckles so that the stored energy then returns the bumper system to its original position.

Dwayne Trimpe, manager, Organic Materials, and Leo Ang, supervisor, Exterior Plastic Applications, Chrysler Motors, report that fascias with molded-in color are being considered. Pigmented fascias would be gray or other dark colors to contrast with body colors. Possible use of polypropylene foam, or materials such as Arco's Dylark, also are being evaluated for the bumper systems.

Under-the-hood efforts include replacement of metal valve covers by thermoplastics or thermosets, including higher-heat ABS and vinyl esters. Chrysler's Jeep sport utility vehicles already have Du Pont Rynite valve covers.

Chrysler has not identified a need to move to higher-temperature interior materials and is maintaining its traditional approach, says John Fillian, supervisor, Interior Plastic Applications. However, the company is preparing for possible future requirements. Use of solar-controlled glass, to screen out radiation for parts that function in the -20 [degrees] F to 175 [degrees] F range, is being explored. Glass suppliers are providing materials that absorb ultraviolet and infrared radiation.

Fillian also expects more emphasis on color concentrates, rather than precolored materials, for possible cost advantages and inventory reduction. More responsibility for color matching is being shifted to the molder level. In addition to the continued pressure to eliminate paint requirements for interior trim, Chrysler is pressing suppliers to take on more product testing.

RIGID MOUNT SYSTEM

The new front and rear 5-mph systems for the 1990-1/2 Ford Escort add bumper area while saving weight and cost. Ed Kure, executive engineer, Exterior Systems, and Paul Guy, executive engineer, New Technology R&D, Ford Plastics Products Div., say that Mazda, designer of the vehicle, subcontracted the development of a rigid mount bumper system to the Plastics Products Div. Replacing the current mount, the design cuts weight about 20% and cost by 10%. Compared with a foam absorber, with fascia and reinforcement, the weight saving can be 10% to 30%.

With an adhesive-bonded GE Xenoy fascia and Xenoy reinforcement beam directly mounted to the car frame, impact energy is absorbed by the plastic structure; shock absorbers or foam is not required. The evolutionary design reflects improved understanding of the plastic material and the impact dynamics. A key to success is that the car bodies are now more dimensionally precise, so that interface elements are not needed to assure proper margins between mating parts.

Ford's Plastics Products Div., especially in light of Corporate Average Fuel Economy (CAFE) standards, is evaluating the car exterior for more opportunities for plastics, including fenders, hoods, and deck lids for 1993 models. Paint-curing cycles tend to be shorter than GM's or Chrysler's and so require a higher temperature--370 [degrees] F--for primers and topcoats.

Ford is checking materials from different suppliers. In one program, reaction injection molded (RIM) polyurea and a thermoplastic, such as GTX, are being studied. Any degradation of flushness or margins, compared with steel, is not acceptable, and plastic panels will not be introduced until differences in expansion and contraction can be compensated for by design. Ford has no present plans for plastic vertical panels in production cars.

Sheet molding compound (SMC) also is being evaluated, possibly for 1993 vehicles. In a pilot project of several hundred Taurus cars, an SMC hood (supplied by Budd Co.) is being studied, to be followed by a polyester deck program, possibly for 1994 models.

Guy says that Ford is working on several areas in plastics technology that, with a highly focused R&D effort, cut across product and process factors. If successfully pursued, he contends, significant competitive advantages would be achieved, possibly by late 1990. Structured around a matrix of potential products, a "well focused" plan targets development and acquisition of data that could permit substantial expansion of plastic usage. At present, however, Kure and Guy cannot say that there is a clear consensus on the growth of plastic exterior parts on Ford cars. While there is more interest in exploring any weight-saving approaches, they believe that resolving remaining fit and finish concerns could accelerate the growth of plastics in Ford cars.

RISING EXPECTATIONS

An independent business unit within Ford, which is its major customer, the Plastics Products Div. currently is also involved in instrument panel design with Chrysler, Mazda, and Nissan. "We function in an atmosphere of constantly rising customer expectations," says Louis J. Chmura, executive engineer responsible for product and process engineering of interior body components. "Customers now expect more services, that we take more responsibility for the design and be the general contractor on the project, and that we deliver a better product without increase in cost."

Chmura says that in a current 1992 program, "we were able to lay out the complete process, from concept to production. With the perspective of total project responsibility, we could plan our route with a truly system approach. Simultaneous engineering eliminates time-consuming information `handoffs,' and style and manufacturing aspects, which could be in costly conflict further downstream, are dealt with efficiently at the beginning. We are being asked to do this now, not by exception, but as normal business procedure."

Reflecting on the industry's global character, Chmura says that in a typical instance, the Plastic Products Div. was asked by Mazda to provide design assistance for an instrument panel that the division would produce. Engineering groups in Hiroshima and at Ford, and interaction at each other's sites, fostered international teamwork for design efficiency.

Security to protect the customers' projects is a major factor. "Over the years we have built customer confidence by performance," Chmura says. "We encourage mutual respect, and the workforce is constantly made aware of the importance of security. We are 100% into computer graphic design and so all projects are protected in the job-partitioned data file."

Improved coordination of the many elements of the car interior is now getting a lot of attention. Front seat concepts are being integrated with the instrument panel in cockpit-type designs that coordinate fit, color, grain, and functional factors, and provide a smooth panel/door transition. The focus is toward a complete interior system, instead of "separate parts."

Component redundancy in current panels is another concern. Typically, for a soft instrument panel, a structural substrate is under a urethane foam, topped by a vinyl skin. Steel brackets for the radio, glove box hinges, and other components; ductwork for climate control and defrosting systems; electrical wiring and harnesses; and numerous gages form a complex array of individual parts. An air bag mounted to the instrument panel on the passenger side, and protective knee bolsters, add more parts to the space and further fragment the overall functionality of the design.

There is major potential to reduce parts and cost and improve quality, Chmura asserts. "Why not consider the entire area as a module to simplify everything behind the instrument panel, for reduced assembly and for economy?" Ductwork that doubles as a structural cross-car beam would also reduce rattling, for example. Ford's Ranger now has ductwork in production that is integral with its instrument panel.

Much more emphasis on combined functions is predicted, together with possible increased metal replacement by stiff composites and engineering thermoplastics. The imperative, always, however, is to achieve higher quality while keeping costs down.

Customers' heightened awareness of the interior--notably the instrument panel area--as an expression of the car's perceived value has removed many previous design constraints. Chmura foresees many innovative approaches, relative to appearance, functionality, and cost, resulting from efficient implementation of the expanded creative freedom.

BUSY MINIVAN MARKET

The new plastic-bodied offspring of the GM 200 program, the Chevrolet Lumina APV, Pontiac Trans Sport, and Oldsmobile Silhouette all-purpose vehicles (APV), are entering a busy market that has shown steady growth in the last few years. A total of 865,000 minivans were sold in 1988, in a crowded field in which Chrysler's Dodge Caravan and Plymouth Voyager sold 435,000 units. In 1987, 699,000 minivans were sold, but only 15,000 in 1982, when Volkswagen was the sole entry in the minivan market.

The GM minivan's large exterior panels of SMC are adhesive-bonded to a galvanized steel space frame. The front fenders of RRIM polyurea are mechanically attached to the space frame and painted with the body, and the flexible fascias are made of RRIM polyurethane. No sheet metal is exposed, except for moldings around the doors and solar control windshield.

GM says the steeply raked windshield, sloped 66 degrees, reflects and absorbs more than 60% of the total solar energy striking the glass. Application of a metallic film 1000 times thinner than a sheet of ordinary writing paper, by magnetic sputtering in a high-vacuum chamber, reduces the solar load to the interior by about 30%. The coated glass transmits shortwave light energy in the visible range and reflects longwave heat energy.

The GM minivan represents the first time that a high-volume vehicle will be assembled by adhesive bonding. Ashland Chemical's two-component Pliogrip polyurethane structural adhesive system is being used for exterior parts and for numerous subassemblies. Adhesive viscosity and curing rate must match the high-speed assembly line.

About 70% of the minivan's exterior panels, including the entire passenger side body and sliding door, rear lift and surround, and front and rear roof, are molded using Ashland's Phase Alpha unsaturated polyester SMC resin system.

COVERING THE BASES

Adgild Hop, manager, Automotive Market Development, GE Plastics, says the company is positioning itself to provide a range of materials with flexural moduli from 20,000 to 6 million psi. New continuous glass-reinforced thermoplastic composites with flexural moduli up to 2.5 million psi, with a very low viscosity resin to wet-out the glass, will be introduced in 1991. Front ends and floor pan parts, based on closed mold technology, are some targets.

Hop also sees good design and weight-saving potential for polyphenylene oxide-based GEcet foam, for uses such as instrument panels, steering column housings, consoles, and knee bolsters. In one method, the foam would be injected over a skin pre-placed in the mold.

Hood and trunk tools are already committed to GE's Alpha I multiple-process machine, slated for start-up early next year at the company's new Polymer Processing Development Center. Key Alpha I development projects will include novel bumper systems that combine composite and noncomposite thermoplastics, using unidirectional glass for beam stiffness, and non-reinforced materials for energy management. "We want to make on-line paintable, soft front and rear ends backed with composite structure, based on our elastomeric Lomod technology," Hop says, "and to control softness throughout different areas of the vehicle. It is within reach to create a total relatively soft and resilient system, including fascia, front fenders, and hood, with greater design freedom."

GE Plastics is working with the car manufacturers on different bumper systems and developing a new generation of Xenoy products. For vehicles between 1500 and 2300 lbs, one direction is the adhesive-bonded fascia and box beam structure. At about 3000 lbs, the effort is toward blowmolded and injection molded Xenoy bumpers with integrated energy absorbers. At about 3500 lbs, Hop sees possible use of the unidirectional Azdel materials. For heavier pickup trucks and vans, Azdel-reinforced designs with chrome-plated or matte steel surfaces could be one-third the weight of a steel bumper.

SAVINGS IN TOOLING

The feedback on the Cadillac's 375 [degrees] F, E-coatable GTX front fender has all been positive, not least because of the savings in design time and tooling investment. GE will offer varied materials to meet the heat requirements of specific paint systems.

"Savings in tooling is a major reason to use more plastics in cars," Hop says. "Tooling for four steel doors can run as high as 35 to 50 million dollars. For the doors in plastic, tooling can be provided for about 10 million dollars, and in about one-third the time. Automakers will appreciate this more in relation to their limited-production niche markets."

GE Plastics also is working on the modular instrument panel concept and on a plastic air-intake manifold, possibly with their Supec or modified GTX materials, to replace aluminum. The Azdel radiator housing and ducting system on the 1990 Corvette has shown superior fatigue resistance. Additionally, with about 10 active fender programs, eight committed Azdel bumper systems, and three blowmolded bumper programs, the company has a full plate of projects.

In a final word, Hop looks for the industry to promote easier disassembly of parts, as a step to more recycling of automotive plastics.

KEY FACTORS

Some key factors are expanding the opportunities for Du Pont's materials and technical services, say Joseph A. Miller, general director, Automotive Products Dept., and Henry B. Milligan, director of sales and development, Engineering Materials, Du Pont Co.

After a regulatory hiatus during the Reagan Administration, the prospect of stiffer federal legislation, such as a reinforcing and possible extension of the CAFE standards, has deepend the interest in plastic car exteriors. About 4 lbs can be saved with a plastic fender, compared with steel. "Under-the-hood evaluations, including those for air intake and manifold systems, hoses, and various housings, will generate a new wave of high-performance, lightweight designs," Miller and Milligan predict. Use of new, non-CFC, possibly less efficient refrigerants may replace Freon 11 and Freon 12, as one example. The result will be larger and heavier air conditioning systems, and designers will be pressured to more aggressively seek solutions using plastics.

Possible legislation on use of alternate fuels, such as methanol and ethanol, also cannot be discounted. If passed in California, will the rest of the nation be far behind? Fuel systems then would need upgrading, possibly even to inert fluoroelastomers, to prevent swelling of fuel-contacting parts.

Du Pont also sees strong plastics potential in the growing emphasis on product differentiation. As many as 570 car models are now sold in the U.S., up from 400 in 1980. With quick model changes critical for many car programs, investment, design, and production strategies require compressed time and cost frameworks. Du Pont regards its total system capability, from materials to coatings and paint, including the thermosetting and thermoplastic elastomers, a wide range of engineering polymers, fibers and composites, and its strong compounding technologies, as an effective base for fast design and manufacturing response.

Development programs include plastic intake manifolds, rocker valve covers, fuel tanks, air induction systems, fans and shrouds, and cross-car members. The company's polyester-based technology, for parts from very flexible to very stiff, encompasses capability, with its glass-reinforced Bexloy 550 polyester, of on-line painting, through the electrodeposition white-on-white coating process at up to 400 [degrees] F.

HOTTER INTERIORS

The 1990 models reflect the need to design for higher interior temperatures, of about 250 [degrees] F, between the windshield and instrument panel, and up to 210 [degrees] F in other above-the-belt-line parts of the car. The accented rake of the windshields and more glass largely account for the 20 [degrees] F rise in the interior on a warm day.

High-heat ABS plays a major role in providing moldability, rigidity, and impact strength at elevated temperatures. Roy Palasek, market development specialist, Automotive Plastics, Monsanto Chemical Co., reports that the 1990 GM Pontiac Grand Prix, Buick Regal, and Oldsmobile Cutlass Supreme coupes are using Lustran Elite HH for the rear interior quarter panels, A- and B-pillars, door panel substrates, roof rails, and all plastic trim above the belt line. The material likewise is used in the new Chevrolet Lumina.

The new Lincoln Town Car has moved to Monsanto's Cadon 160, an ABS/SMA alloy, for the A-, B-, and C-pillars and roof rail. Standard Lustran 246, a general-purpose ABS grade, is selected for the four door panels below the belt line.

The trend to higher interior temperatures is expected to continue. Monsanto is working on higher-heat grades of Lustran Elite HH, with capability to 240 [degrees] F for various interior trim applications, for 1992 models.

U.S. auto manufacturers are all introducing passive restraints in 1990, many as options. All Chrysler vehicles will have an air bag mounted in the steering column as standard. Redesigned instrument panel areas now include knee bolsters under the steering column. Palasek says Lustran 1146 high-impact ABS is used on the Dodge Daytona, Chrysler Le Baron, and Omni Horizon and America.

The incompatibility of high-performance engines and the desire for quieter interiors makes sound attenuation more important. Robert Lietz, market manager, Automotive Elastomers Group, Monsanto, says that special sound-deadening grades of Santoprene thermoplastic elastomers (TPEs) can reduce noise transmission to the passenger compartment. In the Dodge Dynasty and Chrysler New Yorker, the injection molded TPE wraps around the transmission solenoid valve and provides noise attenuation of over 3 decibels.

A Santoprene dash mat, functioning between the engine and firewall at continuous temperatures of 275 [degrees] F and above 300 [degrees] F for intermittent excursions, also reduces sound. In the 1990 Buick, Oldsmobile, and Pontiac, the 0.100-inch-thick part, developed by Cascade Engineering, replaces a more complex double metal wall assembly filled with sound insulation.

Lietz projects a worldwide market for the ozone-resistant Santoprene material of about 3 lbs per car by 1992. Targets include rack and pinion boots, suspension struts, and brake and transmission cable covers.

Clean air ducts of Santoprene are now on the 1990 Ford Probe. In cooperation with Structural Dynamics Research Corp., a technique was developed that permits the air duct to be designed for minimum wall thickness while preventing collapse points along the duct length. Lietz says that traditionally used thermoset rubbers display limited capability of providing the needed duct convolutions with uniformly thin cross sections. Blowmoldability is also a plus.

BECOMING COMMON

Bumper beams and leaf springs similar to the structural RIM glass-reinforced polyurethane front bumper beam and the epoxy composite leaf spring on the 1990 GM Corvette "are becoming common for all three U.S. car producers, as well as globally," says Richard Dolinski, vice president, Automotive Materials, Dow Chemical Co. Also installed on GM's Pontiac Grand Prix and the Toronado, the highly stiff, 7- to 9-lb, 60% to 70% glass-reinforced leaf springs are more durable than and about one-fifth the weight of their steel counterparts.

Other structural parts on the boards are cross members for engine supports, and load floors, rocker and valve covers, and oil pans of Derakane vinyl ester and glass, competing with nylon, phenolic, aluminum, and steel. The pace of developments in RIM and resin transfer molding (RTM) manufacturing technology is one factor. Gains already made in automating RIM machines reduce cycle times and flash. RIM polyurea front fenders on the new GM minivan, on-line paintable to 325 [degrees] F, are the leading vertical panel use of the material.

With their 250 [degrees] F capability, Dolinski says, there is a growing

market for the company's Pulse polycarbonate/ABS blends, now specified for over 30 different car models. Magnum 357 HP ABS, a new low-gloss, pigmentable grade capable of 220 [degrees] F continuous service, features low melt viscosity for easy processability. Higher-temperature under-the-hood environments are even affecting wheel cover specs. The Pulse resins are a contender.

LARGER PORTFOLIO

Mobay Corp.'s significantly increased involvement in automotive in the last few years reflects a greatly broadened product portfolio. As Dieter Neuray, director of marketing, Plastics Dept., Plastics and Rubber Div., puts it, apart from its position in polyurethanes, the company in the past was basically considered a polycarbonate supplier. Today, however, Mobay's automotive materials, including the polyurethanes, polyureas, and structural RIM, range from low-moisture-absorbing nylons to polyphenylene sulfides and numerous blends. Bayblend polycarbonate/ABS is used on Ford and Chrysler models for wheel covers and is under evaluation for instrument panel parts. Neuray says that the polycarbonate/PET Makroblend materials, with wider processing windows and improved chemical resistance, are being considered for bumper fascias.

Petlon polyester resins find application under the hood in ignition systems, and for grille opening panels and window guides in 1990 models. The Nydur nylons are under evaluation for valve covers and intake manifolds.

Earlier this year, Mobay introduced Tedur polyphenylene sulfide into the U.S., targeting the material's chemical and temperature resistance for under-the-hood applications related to fuel system parts, such as pump housings or other components in constant contact with oil and grease. Neuray also projects potential for conductive Tedur grades in uses such as mirror housings.

A total of about 42 lbs of Mobay's Bayflex 110 RIM polyurethane is used for the front and rear bumper fascias, the front fender extensions, and front and rear door extensions on GM's APV minivan. In a fleet of 1989 cars, a U.S. automaker also is evaluating flexible rear bumper fascias injection molded of a Texin 4210 thermoplastic blend of urethane and polycarbonate.

OLEFIN INVASIONS

The thermoplastic olefins (TPO) are pressing to invade engineering resin applications. Himont Advanced Materials' new HiFax materials typify the effort. Denis Smith, vice president, says that in Europe, TPOs are beginning to replace elastomer-modified polycarbonate bumpers on cars and modified polyphenylene oxides (PPO) in instrument panels. HiGlass olefin-based composites are replacing glass-reinforced nylons, acetals, modified PPOs, and other glass-reinforced engineering plastics while providing comparable heat distortion, mechanical, and impact properties. Smith adds that the materials' weatherability, paintability, flame retardance, durability, and moldability are further advantages. With 10 regional plants producing the company's materials, and with eight technical centers in the U.S., Europe, and Asia, Himont is well positioned to respond to carmakers' global needs.

Himont currently has a project with GM to improve the weatherability of interior and exterior parts. "During the past two years, components such as windshield moldings, interior door and quarter panels, and exterior molded-in color fascias have been developed with Himont materials," says Thomas Evans, superintendent, Process Engineering, Inland Fisher Guide, GM. "Tests show a 300% reduction in fading caused by ultraviolet rays. We are encouraged and are researching the weatherability of other exterior parts as well."

FOAM'S EXPANDING ROLE

Uses of foam in cars are expected to grow over 10% a year for at least the next five years. Foam is now used for storage compartments for air bags and for interior parts such as impact-absorbing knee bolsters.

The shorter lead times of limited production runs for niche markets also are advancing foam usage. Tooling requires only 6 to 12 weeks, compared with what could be a year or more for tools for solid injection molding.

ARCO Chemical Co. reports that in addition to knee bolsters, its Dytherm expandable copolymer is being specified for floor consoles, sun visors, load floors, and spoiler cores for models produced in the U.S., Europe, and Japan. Chevrolet's Outdoorsman includes a standard floor console with an integral cooler of Dytherm copolymer. A rear console is optional. (See PE, August 1989, p. 10.)

Evaluation programs include header and instrument panels, A-pillar trim, steering wheel hubs, and door panel fillers. Moldable bumper systems with ARPRO expandable polypropylene cores absorb repeated impacts. With tailored densities, the fascia can be supported with less material and produced with lower assembly costs.

More than 60 million cars in the U.S. alone apply ARCO's Dylark resins for instrument panel substrates, glove box doors, headliners, and trim parts.

HIGHER HEAT LOADS

Albert Winterman, director of automotive marketing, BASF Corp. Plastic Materials, adds aerodynamics to higher under-the-hood temperatures as another demanding factor. More streamlining may reduce the car's drag coefficient from about 0.35 to 0.25. As the front end's slope changes to smooth airflow and boost fuel efficiency, the "tighter" engine compartment adds to the heat load.

Winterman believes the hotter engines foretell more growth for nylon, which is already used in radiator end tanks, engine fans, air cleaners, and power steering and brake fluid reservoirs, as well as a range of electrical, cooling, and fuel system parts. Ultramid A3WG7 glass-reinforced nylon 66 resin now is being evaluated for auto engine air-intake manifolds and fuel system parts, such as fuel rails.

A new high-temperature contender, a carbon-fiber-reinforced nylon 66 resin, Ultramid A3WC4, which is tailored for highly stressed rotating parts and housings, offers a flexural modulus of 1500 kpsi; and mineral-filled Ultramid 85 has a heat deflection temperature at 66 psi of 385 [degrees] F.

Dietrich Schlotterbeck, business manager, BASF Automotive Urethane Specialties, sees RIM polyurethane steadily gaining in car interiors, including door and sunroof panels, seat backs, pillar coverings, rear shelves and roof liners, and air bag deployment systems.

Glass-mat-reinforced panels for Mercedes seat backs, with vinyl or cloth to match interior color schemes, are an application for low-density, semirigid Elastolit SR structural RIM polyurethane. Schlotterbeck says that sunshades for the sunroofs of 1989 Chrysler A-, G-, and J-body cars are the first automotive interior panel usage in North America for low-density structural RIM urethanes.

Thermoformed self-supporting headliners are contenders for sound absorption and thermal insulation. TF-Trilaminate, a pre-manufactured sandwich material, consists of BASF's TF-F urethane foam sheet, with two outer surfaces of the company's Colback nonwoven fabric.

POLYESTER FASCIAS

Hoechst Celanese's Riteflex BP thermoplastic polyester elastomer alloys, now on Buick, Cadillac, and Oldsmobile fascias, are being evaluated for other applications. John Bobick, marketing manager, Automotive Applications, Riteflex and Vandar, reports that three grades, with moduli of 50,000, 80,000 and 110,000 psi, are used. The company just announced Riteflex BP 9057, with a flexural modulus of 50,000 psi. Suited for interior and exterior uses, the resin is a variant of a BP 9056 grade, with a broader temperature range.

Several Riteflex thermoplastic polyester elastomers, for uses including wire coatings, are now being commercialized--one with hardness below 40 Durometer, another with a 63 Durometer intermediate hardness.

If alternate fuel systems become a reality, Ray Atherton, manager, Market Development, Automotive, sees a growing role for the inherently flame-resistant, higher-temperature-resistant, and alcohol-resistant Fortron polyphenylene sulfide and Vectra liquid crystal polymers. Also, with the increase in aluminum prices, some companies are evaluating Celstran long-strand fiber-reinforced thermoplastics as possible future replacements. One new use for Fortron PPS is as a replacement of nylon for valve covers.

MAJOR EXPANSIONS

Eastman Chemicals Div. of Eastman Kodak Co. recently announced a diverse $300 million capital investment program at its Texas Eastman Longview facilities, which is intended to reinforce its position as a major global materials supplier in the automotive and other major markets.

A new polypropylene plant, the company's third, scheduled to come on stream in the second quarter, 1991, will add 220 million lbs/yr to the more than 300 million-lbs/yr capacity of its two existing plants. The polypropylene plants will be supported in new product development with a pilot facility for process modeling and product development.

Eastman's original polypropylene plant, built circa 1960, uses the company's solvent process; a new polypropylene plant, which was brought on stream in March, uses the two-reactor Unipol process, as will the forthcoming plant. The polypropylene grades yield improved properties by direct copolymerization with an impact modifier, thus eliminating secondary compounding steps to build impact resistance.

Other parts of the major expansion program include a new, and third, polyethylene gas-phase "swing" plant of 250 million-lbs/yr capacity (on top of the company's existing 650 million-lbs/yr polyethylene capacity), which will go on-line in 1992 and will produce both linear low-density and high-density materials. A polyethylene pilot plant also will go into service at about the same time for product development in support of the expanded facilities.

A new 50 million-lbs/yr amorphous polyolefin facility to start up in mid-1991 to produce sealants and adhesives, and an expanded capacity to 45 million lbs/yr in 1991 for production of Eastman's Eastotac tackifying resins will absorb the remainder of the large capital expansion budget.

Automotive is Eastman Chemical's largest market for polypropylene, basically in competition with ABS for interior parts, including pillar trim covers, and trim, cowl, rear quarter and door panels. With polypropylene's tight supply in the last few years, Robert E. Scales, market manager, Plastics, sees the expanded Unipol process output offering substantial growth opportunities.

Eastman is developing an "improved" polypropylene-based fascia material expected to be commercial later this year. Scales projects success in the fascia market for the lower-cost, lighter-weight thermoplastic olefins, in particular in vans and pickup trucks.

For upper body pillar covers and other interior applications, Eastman Chemical is supplying talc-filled impact-modified polypropylene copolymer grades to a Japanese molder for a Japanese auto manufacturer in the U.S. and Japan. Heat distortion capability (248 [degrees] F at 66 psi and 153 [degrees] F at 264 psi) higher than unfilled impact-modified grades falls between the unfilled polypropylenes and the high-heat ABS grades.

VERSATILE POLYURETHANES

The polyurethanes and their derivatives, the isocyanurates and polyureas, build on their broad automotive application base, ranging from seat cushions to fascias, vertical exterior panels, and structural RIM bumper beams and chassis parts. Ross H. McMillan, director, Strategic Business Development and Group Communications, Formulated Products Div., ICI Polyurethanes Group, says that "the on-line paintable polyurea materials are being evaluated for fascias and vertical panels for at least seven new vehicles being designed by the Big Three."

McMillan projects growth of the MDI (diphenylmethane diisocyanate)-based polyurethane foams to produce full-trimmed seats, armrests, headrests, and sun visors, possibly replacing the now predominant TDI (toluene diisocyanate) materials. "Seating in future vehicles," he predicts, "will rely on ergonomically designed comfort zones, based on the concept of multiple hardnesses and varying densities to build levels of softness and support into specific seat areas." Fast-curing MDI foams' wide hardness/softness range is achieved within single polyurethane systems by varying isocyanate/polyol ratios. Some seat-makers are evaluating ICI Polyurethanes' reduced chlorofluorocarbon (CFC) or CFC-free MDI formulations.

Ford produces a quieter interior with MDI-based polyurethane foam molded onto the back of the 1989 and 1990 Lincoln Continental's carpets, and will similarly apply the material in the 1990 Town Car. McMillan projects possible expanded "quieting of the ride" with MDI foams for other interior uses, such as headliners, C-pillars, and rear seat insulators.

SILICONES

About 30 silicone uses in an average U.S. car, as adhesives, fluids, or elastomers, could double by 1995, says Donald Finney, manager, Advanced Automotive Concepts, GE Silicones. A new transparent, thixotropic, one-component silicone adhesive offers improved low-temperature energy absorption for thermoplastic bumper systems. Full primerless bond strength is achieved in four days, rather than the more typical seven days of competitive primed systems.

One automaker uses a special silicone fluid to saturate EPDM weather stripping for car doors and windows, providing improved weatherability, anti-squeaking properties, and abrasion resistance.

Silicone rubber hose, long used in heavy-duty police car, ambulance, and truck cooling systems, is targeted for passenger cars. Silicone foam's thermal, acoustic, and flame-retardant properties also are expected to find new uses as the need grows for higher-performance materials.

RANGE OF RESINS

The automotive focus for Amoco Performance Products' seven resin lines has been in lighting, electrical, mechanical, and trim areas. Chrome-plated Mindel resins are used, for example, in interior reading lamps on three 1990 Chrysler car lines, and high-heat-resistant, clear Udel polysulfones are used for vanity lamp lenses and for colored fuse bodies. Xydar liquid crystal polymer's high-temperature resistance and ability to fill thin sections are applied for electrical circuit encapsulation. James K. Doty, automotive industry manager, sees rapid growth in the automotive fuse and power distribution market for Radel polyarylsulfone, in response to new and upcoming electrical system requirements, including multiplexing, antilock brakes, electrically activated transmissions, electronically controlled fuel injection, and electronic steering.

Amoco also sees a niche for special formulations of its Ardel polyarylate for weatherable exterior painted trim. Torlon polyamide-imide finds uses as thrust washers and seal rings, and has strong potential for bearings and bushings in starter motors, alternators, and wear-resistant engine components.

PHOTO : GM minivan's large exterior SMC panels are bonded to the space frame. Polyurea RRIM

PHOTO : fascias, and fenders, painted with the body, are mechanically fastened.

PHOTO : Glass-reinforced composite, exterior left-side body panels for GM's 1990 minivans move

PHOTO : along conveyor line at Budd Co.'s new Kendallville, Ind., plant.

PHOTO : Mounted directly to the car frame, the new Ford bumper system utilizes the rigid plastic

PHOTO : assembly to absorb impact energy without the need for shock absorbers.

PHOTO : Front fenders, being fleet-tested by Chrysler, are injection molded of Du Pont's Bexloy

PHOTO : K-550 thermoplastic polyester. They undergo electrocoat oven temperatures.

PHOTO : Production of 16-lb developmental rear fascia for GM Corvette uses ICI's polyurea system

PHOTO : with delayed action before polymerization for proper mold filling.

PHOTO : Transparent red lens is molded of Amoco's Ardel polyarylate. The Mindel resins for the

PHOTO : reflectors are platable on conventional ABS lines.
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Title Annotation:plastics in automobiles
Author:Wigotsky, Victor
Publication:Plastics Engineering
Date:Sep 1, 1989
Words:5630
Previous Article:1989 ANTEC wrapup: report from New York.
Next Article:Computer-aided design in thermoforming.
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