Silicones for Automotive Applications

Standard silicone elastomers are not really suitable as sealants in the hot areas of engine cooling circuits. At K 2013 Wacker has presented a new coolant-resistant silicone. In its cured state, Elastosil LR 3022/60 ensures excellent sealing properties, since it retains a low compression set, even under long-term load in direct contact with coolants. Measurements show that the compression set of the silicone is no greater than 50 percent even after a thousand hours in a coolant at a temperature of 125 degrees Celsius. This makes the novel silicone a suitable choice in the manufacture of molded seals for engine cooling circuits. It is designed for injection molding. Also for automotive and mechanical engineering applications Wacker has developed solid silicones with excellent damping properties. Elastosil R 752 silicones cure to form elastomers that are significantly less elastic than standard silicone rubber. They have a strong damping effect on shocks and undesired vibrations. At the same time, they possess all the typical properties of silicones, such as heat resistance, low-temperature flexibility and aging resistance. With these two new grades, which cure at Shore A hardnesses of 30 and 70, the product line covers a very practical range of hardnesses. All Elastosil R 752 grades are peroxide curing solid silicone rubbers and can be processed by conventional compression molding and by injection molding.