Instrument panel, automotive polymers

Automotive appbcations account for about 116,000 t of woddwide consumption annually, with appbcations for various components including headlamp assembhes, interior instrument panels, bumpers, etc. Many automotive appbcations use blends of polycarbonate with acrylonitrile—butadiene—styrene (ABS) or with poly(butylene terephthalate) (PBT) (see Acrylonitrile polymers). Both large and small appliances also account for large markets for polycarbonate. Consumption is about 54,000 t annually. Polycarbonate is attractive to use in light appliances, including houseware items and power tools, because of its heat resistance and good electrical properties, combined with superior impact resistance. 

STYRENE-MALEIC ANHYDRIDE. A thermoplastic copolymer made by the copolymerization of styrene and maleic anhydride. Two types of polymers are available—impact-modified SMA terpolymer alloys (Cadon ) and SMA copolymers, with and without rubber impact modifiers (Dylark ). These products are distinguished by higher heat resistance than the parent styrenic and ABS families. The MA functionality also provides improved adhesion to glass fiber reinforcement systems. Recent developments include lerpolymer alloy systems with high-speed impact performance and low-temperature ductile fail characteristics required by automotive instrument panel usage. 

Glass-reinforced SMA polymers are used as electrical connectors, consoles, top pads, and as supports for urethane-padded instrument panels. There are seveial additional automotive uses. SMA aie also found in coffee makers, steam curlers, power tools, audio cassette components, business machines, vacuum cleaners, solar heat collectors, electrical housing, and fan blades, among others. 

Major polymer applications electronics (computer and television housings, keyboard frames, interface boxes), automotive (instrument panels, interior and exterior trim, glove compartments, wheel covers, electric connectors, ftise boxes), air conditioner housings, hospital and office fiimiture, production of blends... 

This section discusses elastomeric materials such as thermoplastic elastomers (TPEs), TPVs, and other rubber systems such as thermoset elastomers/rubbers (TSRs) invoked in automotive applications apart from their use as impact modifiers in polymer blends. If one starts from nnder the hood, elastomers are used primarily in belts and hoses, bellows, and gaskets. At the separation between engine compartment and the interior, elastomers are used for sound management. Inside the car, they are used in floors, instrument panel skins, instrument panels for soft touch, gaskets for side mirrors, and so on. Outside the car, they can be fonnd in tires (base tire, treads, side walls) and, finally, they are used in wire and cables and coatings in almost aU parts of the car as needed. 

Reducing the section thickness to the level of foils and films allows many more polymers to become transparent. Although films technology is very highly developed nowadays, it has only a few points of contact with automotive design, e.g., in the use of oriented polyester film for membrane touch switches and instrument panel display. 

The growth in use of polyacetals for automotive applieations has been much more influenced by its replacement of metal rather than other polymers. There is a potential threat to polyacetals from polyamide. Some OEMs may be encouraged to switeh from POM to polyamide for interior applications such as instrument panels, grilles and switehes, because of the higher formaldehyde emissions from POM. 

The better heat resistance and conductivity have led to replacement of other polymers by PPO/PPE in bumper systems. Also, its better heat resistance and lower odour emissions give PPO/PPE an advantage over PC/ABS for instrument panels. PPO/PPE does however face tough competition from other polymers in key application areas, and manufacturers must convince automotive designers and component manufacturers that it is a better product in terms of quality and total systems cost for it to displace other established systems. 

Rotational plastisol and powder molding now compete in production of automotive interior surface layers for PUR foam structures (e.g., instrument panels, crash pads, and arm and head rests). Tooling and compound costs generally favor the use of plastisols, increased antifogging requirements the use of powders. Powder technology also opens this area to polymers other than PVC future developments should be of interest. 

A variety of polymers. Flexible and semi-rigid PVC applications such as automotive body side molding, instrument panels, glove boxes. 

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