Study of Rubber Curing Process (Relation between Unsteady State Temperature Field and Cure State)

Abstract

Study of a curing process of rubber has been conducted. Two kinds of rubbers, vulcanized and compounded SBR rubbers, were tested. The rubber was packed in a cylindrical container of inner diameter 74.6 mm. The container was controlled at a uniform, constant temperature, ranging from 403 to 433 K, and radial distributions of the temperature and cure state during the process were measured. For the two cases, typical temperature fields for unsteady, one-dimensional heat conduction problems were observed. However, the uniform temperature field was formed faster for the compounded rubber than for the vulcanized one. At the terminal period of the curing process, a slight temperature decrease toward the container wall was also observed in the rubber, and this implies the existence of the heat flow toward the container wall. These phenomena may be due to the influences of the reaction heat. Previous chemical reaction model of the cure state was compared with the present data, and good agreements were obtained. This conclusive result brings better understandings for the practical production problems.