Polymer interior trim

Polystyrene. Polystyrene [9003-53-6] is a thermoplastic prepared by the polymerization of styrene, primarily the suspension or bulk processes. Polystyrene is a linear polymer that is atactic, amorphous, inert to acids and alkahes, but attacked by aromatic solvents and chlorinated hydrocarbons such as dry cleaning fluids. It is clear but yellows and crazes on outdoor exposure when attacked by uv light. It is britde and does not accept plasticizers, though mbber can be compounded with it to raise the impact strength, ie, high impact polystyrene (HIPS). Its principal use in building products is as a foamed plastic (see Eoamed plastics). The foams are used for interior trim, door and window frames, cabinetry, and, in the low density expanded form, for insulation (see Styrene plastics). 

New polymer structures allow the control of processability and final characteristics. For example, Mitsui is launching nanostructured metallocene alpha-olefins that have a crystallite size of the order of nanometres instead of microns as for conventional metallocene polyolefins. This yields a better balance of transparency, heat resistance, flexibility and elasticity characteristics. Targeted applications are automotive interior trim, packaging film, construction materials, protective films for electronic and optical parts, sealing products and as polymer modifiers. 

Table 3.5 presents the various types of polymer materials used in a vehicle, their quantities, and their approximate mass. At 20 kg, interior trim represents the highest amount of polymer usage, followed closely by the dashboard and seats. 

Problems associated with the deposition of "fog on automotive windscreens have been with us for many years, but only relatively recently has this problem assumed real importance, as most of the major car companies in the USA, Europe, and Japan now ask for compliance to their own fogging tests for most interior trim components. The problem is not specifically related to cellular polymers, and indeed much of the interior trim can be seen not to be cellular. It could also be true that most of the windscreen fogging is derived from air external to the car interior, e.g.. exhaust fumes from traffic. 

Ease of processing is an important advantage in all branches of polymer technology, and one that has been important in developing applications for plasticized PVC Unlike the more conventional rubbers listed above, plasticized PVC is a thermoplastic elastomer, which can be extruded, calendered, or melt-coated on to fabrics and other substrates. Without the support of a fabric or other base, it suffers from a relatively low tensile strength and tear resistance. On the other hand, it is a good electrical insulator, and is inexpensive there is little difference in price between plasticized and unplasticized grades of PVC. Applications include cable insulation and interior trim for cars. 

Boldizar, A., Klason, C., Kubat, J., Naslund, R, and Saha, P. 1987. Inst. J. Polym. Mater., 11, 229. Henstock, M. E. 1988. Design for Recyclability. The Institute of Metals, London, England. Haylock, J. C., Addeo, A., and Hogan, A. J. 1990. Thermoplastic olefins for automotive soft interior trim. SAE International Congress and Exposition, Detroit, MI (Feb. 26—March 2, 1990). 

Non-FR grades of PC/ABS blends are primarily used in automotive components (e.g., interior-trim panels, knee bolsters, and nonstructural interior filler panels) where cost is an issue and thermal requirements do not necessitate use of a more expensive polymer such as PC, but ductility is important. 

The amount of plasticizer added to a polymer varies depending on the effect required. A small addition of plasticizer may be made to improve the workability of the polymer melt. This contrasts with large additions made with the specific intention of completely transforming the properties of the product. PVC without a plasticizer, ie, unplasticized PVC (PVC-U), is used in applications such as pipes, siding, and window profiles. With plasticizer added, articles such as automotive interior trim, jacketing, cable insulations, and PVC floorings are formed. 

In automobiles, besides the large plastics parts, there is a substantial quantity of polymers that cannot be easily separated, viz. the interior trim made of PP, ABS, PC/ABS, PPE/PA, POM, etc. Recycling these commingled resins is more challenging, owing to lower value and high diversity of compositions. However, in some cases recycling can be simple — it was found that contamination of PP by as much as 15% of POM do not have detrimental effects on tensile properties, and it increases the modulus. The blends of PC/ABS as well as those of PPE/PA have also been profitably recycled. 

Various polymers are used in over 1,000 different parts of all shapes and sizes, from instrument panels and interior trim to bumpers and radiator grilles, fuel tanks and engine parts. The material selection for a particular application will depend primarily on the ability to meet the required specification and also on polymer price and total systems cost. The total systems cost includes the cost of the polymer, processing cost and tooling and assembly cost, and is a prime consideration for cost-conscious car manufacturers. 

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... 

In this chapter we will discuss the basic families of materials used in today s automobiles. We will concentrate on polymers, although the chemist s role deals with all materials used in a vehicle. The use of polymers has steadily increased ever since their introduction into a vehicle s structure. Exterior as well as interior parts and trims made from polymers are increasingly replacing traditional steel or aluminum parts [1], The drive for mass and cost savings is enhanced by the material s ability to be customized and to decrease material cost. Coatings are applied to interior parts as well as to exterior parts to enhance appearance and provide corrosion resistance. Stabilization is required of many of the polymeric components (this topic is addressed in Chapter 4). 

Uses Outdoor-weatherable injection molding resin for interior and exterior automotive/truck/RV trim and parts, building and construction applies., window frames, streetlight housings, road signs, etc. modifier for polymers incl. PVC... 

Automotive applications range from window seals and gasketing to enhanced noise/vibration attenuation. The polymers are candidates for automotive seating, interior padded trim and insulation, hospital padding, and topper pads. SEES is extruded/blown into 1-mil films for disposable gloves for surgical/hospital/dental, food/pharmaceutical, and household markets. ... 

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