Patent ID: 8961857
Filing Date: 2015-02-24
Classification: B29C,B29D,B29K,B29L,B32B,Y10T

Abstract:
1. A method of manufacturing an expandable bladder for tyre-vulcanising apparatuses, comprising the steps of: preparing at least one first elongated element comprising a first raw elastomer material and at least one second elongated element including a second raw elastomer material having a different composition from that of the first elastomer material; laying said first elongated element on a toroidal support in the form of coils wound around a geometric axis of said toroidal support so as to form a first layer of said first elastomer material; laying said second elongated element on said toroidal support in the form of coils wound around the geometric axis of said toroidal support so as to form a second layer of said second elastomer material at a radially external position to said first layer, said first and second layers having an undulated interface profile wherein said interface profile defines mechanical-engagement elements between the first and second elastomer materials; mutually coupling the first and second elongated elements in the longitudinal extension of same for preparing a continuous strip-like element that is wound around the geometric axis of said toroidal support during the layering step; vulcanising said bladder.