Improvements in or relating to the preparation of gas-expanded rubber and like material

摘要

506,077. Sponge rubber. EXPANDED RUBBER CO., Ltd., and LAUTOUR, F. DE. Dec. 30, 1937, No. 36119. [Clas, 70] In the manufacture of gas expanded rubber the rubber is partially vulcanized usually to between two and fifteen per cent of the final cure, gassed at atmospheric temperature, and subsequently heated in a mould to complete the vulcanization and expansion of the gas. The pressure in the gassing chamber at the completion of the gassing operation is preferably released rapidly in order to cool the contents of the chamber so they may be readily removed ; the cooling effect may be prolonged by conducting the cooled gas through a jacket around the gassing chamber. A mixture of gas soluble in the rubber and gas insoluble in the rubber, for example a mixture of nitrogen and carbon dioxide, may be used for the gassing operation. Specifications 358,967 and 488,915 are referred to,