Specialty Elastomers for Automotive Applications

Abstract

Abstract Various elastomers are used for automotive components because of their physical properties, chemical properties, durability, etc. There are belts to transmit energy, seals to support radial or reciprocating parts, gaskets and O-rings to seal in oils and fuels, hoses to deliver liquid and gases and diaphragms to control them. Figure 1 shows one example of elastomers for gasoline engines reported by Akema and Yoshida. Rubbers are soft polymeric materials having generally 100 MPa of Young's modulus (shown in Figure 2) for the normally applied temperature range. They are widely used for the buffer position between high modulus materials such as metals, plastics, glasses, etc., in energy transmission, liquid delivery, and energy isolation positions. The materials are selected for their resistance to fuels, oils, and heat; as well as their cold flexibility and sealing ability. However, different materials are sometimes selected for the same device depending upon such factors as applied temperature, class of fuels and oils, and the engineering design of the car. The many problems confronting the automotive industry these days are shown in Table A-I. They are roughly classified into two areas: environmental and safety. Elastomers for automotive applications have been changing to solve many kinds of problems. Table A-II shows the trends of rubber materials being used for automotive parts. High performance rubbers, which have heat resistance, long life, low permeability, good abrasion resistance, and so on, are all being adopted.