STOPPERS OF COMPOSITE CORK MATERIAL FOR SPARKLING WINES AND THE PROCESS FOR THEIR PRODUCTION

摘要

This invention concerns stoppers made from composite material for sparkling wines consisting of two types of cork agglomerate which are closely bonded and produced from two ranges of granulates of different granulometry, where the joining surface between the two agglomerates is irregular due to their interpenetration. The invention also concerns the production process of these stoppers by individual moulding (piece by piece), whereby the simultaneous feeding of the two types of granulate and the respective additives is done and the mould is closed by compression and then heated for a time for polymerisation. The granulates used are normally treated with a reactive agglomerant consisting of, for example, quasi-prepolymer based od TDI or quasi de-moulding, the unfinished stopper is stabilised, and later machined to the final dimensions.