Alternatives to Asbestos in Cylinder Head Gaskets

Because of the health risk of fine asbestos fibres, gasket manufacturers are forced to look for alternatives to asbestos. Various possibilities of substituting asbestos in cylinder head gaskets are characterised by different problems of development. Elastomer-bonded soft materials, i.e. combinations of synthetic fibres and inorganic non-fibrous materials, can be used in cylinder head gaskets to replace soft-material layers containing asbestos. The contents of the soft-material layers is determined by factors of function and of manufacturing technology. Because of its numerous specific sealing properties, another alternative to replace gasket layers containing asbestos is expanded graphite which has been chemically and thermally treated. A non-asbestos cylinder head gasket, already in use today, is that of the metal-elastomer design which is known to be suitable for sturdy engines of high stress. By slightly modifying this design, this type of gasket can also be utilised for other engines.