Automotive fascias

Group 1 Hard segment levels <50%. This group includes engineering rubbers (high performance elastomers) and would include some automotive fascia. 

Polyurethane RIM (PU-RIM) was selected for the Initial RIM application of automotive fascia not only because 1t provides the required damage resistance and other performance requirements, but also because the reactivity of the urethane raw materials, Isocyanate and polyol, provide acceptable productivity. Because the urethane mnomers can be nucleated, high quality sink free surfaces that are suitable for automotive exteriors are produced at the time of demold. Little, 1f any, post mold surface repair 1s needed 1n preparation for painting the RIM part. 

MAJOR PRODUCT APPLICATIONS electrical connectors, automotive components, automotive fascia, automotive seals, gaskets and bearings, aerospace components, friction products, putty compounds, adhesives... 

The premium cost of TPUs can be justified for those applications requiring high levels of abrasion resistance and toughness or low coefficients of friction. These applications include caster wheels, shoe soles, automotive fascia, and heavy-duty hose and tubing. 

Representative applications are tractor body panels and doors, automotive fascia, body panels, window encapsulation, heavy-duty truck bumpers, and recreation vehicle (RV) panels. 

The use of thermoplastic olefins or TPOs is growing at a faster rate than the styrenic block copolymers (SBC) just discussed, or the thermoplastic vulcanizates (TPVs), which are discussed in the next section. The TPO growth rate is currently about 10% annually worldwide. Unlike the SBCs, certain TPOs can sometimes be used at higher service temperatures. Unlike the TPVs (which are derived through dynamic vulcanization), the TPOs are usually used uncured or are only very slightly vulcanized, if at all. This means that the TPOs are usually less costly than the TPVs. The TPOs have been very successful in the automotive industry in replacing the soft polyvinyl chloride compounds used in car interiors. TPOs are commonly available in softness ranges from 60 Shore A to 60 Shore D. A major use for TPOs is in the manufacture of automotive fascias, where appearance is very important. 

SBS and SEBS block copolymers have been employed to impact modify HIPS, PPO/HIPS and various polyolefins. Maleic anhydride modified SEBS offers impact modification of polyamides and polyesters via reactive compatibilization. Chlorinated polyethylene (< 42 wt% Cl) is employed as an impact modifier for PVC, where weatherability is a primary concern [121]. Ethylene-(meth)acrylic acid copolymers and their neutralized versions (ionomers) have been utilized as impact modifiers for polyamides. PBT and PET impact modification with the poly(ester-ether block copolymer) (PBT-poly(tetramethylene oxide) (AB) ) yielded utility in automotive fascia applications. These products have been available under the tradenames Lomod (GE), Bexloy (duPont) andRiteflex (Hoechst-Celanese) [3]. 

Automotive Large volumes of mica are currently used in production of blow molded seat backs for cars and trucks. Injection molded parts include glove boxes, battery trays, fan shrouds, fender liners, and instrument cluster housings. Mica-reinforced polyurethane/polyurea has been used successfully since 1994 in automotive fascia and fenders. 

Table 6 Comparison of the Main Substrates for Automotive Fascia...

While plastics have been established as the material of choice for automotive fascia design efforts to provide more simplified, integrated bumper systems continue. Integration of the traditional steel or aluminum frame and impact-absorbing foam or honeycomb components has been achieved utilizing lightweight injection molded poly(carbonate)/polyester alloy or blow-molded poly(olefin). 

Polyurethane elastomers (some TUP, thermoplastic polyurethane) These terpolymers can be used uncured for most applications however, selected grades can be eross-linked to enhance properties. As a family these elastomers are tough and wear resistant. They have excellent chemical resistance and flexibility. They can have excellent clearity. Applieations include cable jackets. Automotive fascia, connectors, fittings, and many, many more. Ethylene-Propylene-Dlene Terpolymers (EPDM) These terpolymers typically contain a few percent of a diene such as hexadiene. This material is easy to fabricate and then is usually heat-treated at 125"C to 175 C to induce crbss-linking. The physical properties are much different after crosslinking. Commonly, they are heavily formulated for applications which include wire jacketing systems, automotive hoses, and roof sheeting. 

Automotive - fascia bellows, brake cable jackets, CV joint boots, filler panels, side-body trim, tubing grommets, fabric ... 

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