Process for multi-stage dead-end-water tire curing

Abstract

A simple economical multistage vulcanization process is disclosed for producing premium anomaly-free tires wherein the inner liner or curing bladder is supplied with dead end water and steam sequentially in several stages at high pressures which assure thorough diffusion of entrapped air. The internal steam pressure is 250 to 300 psig in stage I to effect rapid heat transfer, the internal water pressure in stage II is from 300 to 450 psig, and the internal steam pressure is 250 psig or higher in the first part of stage III. The overall cycle time for curing radial passenger car tires in 'Bag-O-Matic' presses is reduced one minute or more by using internal steam pressures from 250 to 300 psig in stage I and III and reducing the steam pressure near the end of stage III to boil off the residual water.