Bonding of Rubber to Metals

Rubber has been used for many years as a medium for minimizing and absorbing mechanical vibrations. Until comparatively recently, however, its employment for this purpose has been limited by the practical difficulties encountered in uniting it successfully with other more rigid materials, such as metals. At this stage, technical development in the rubber industry fell short of engineering design and manufacturing requirements. Earlier methods for uniting rubber to metal consisted either of attaching the rubber by mechanical means or by using a layer of ebonite between the soft rubber and the metal. These methods, however, were open to criticism, either on mechanical or chemical grounds, and the bond strengths were obtained at the expense of some of the flexibility of the units. Later, derivatives were produced by the action of sulfuric acid on rubber which gave excellent bonding properties, although they were thermoplastic and tended to weaken at temperatures over 60° C. Recently, cements based on rubber hydrochlorides have been put on the market which are superior in all respects to previous types. These are the “Ty-plys”.