Second vulcanization, English name (postcure), is the product formed from the machine, and then put the produced product in the oven for a period of time (180 degrees to 200 degrees, generally two hours or three hours), known as the second vulcanization. Secondary vulcanization is also called post-vulcanization. Commonly used for vulcanization of silicone rubber, fluoro rubber and fluoro silicone rubber.


The role of secondary vulcanization: When silicone rubber is vulcanized by peroxide, after the decomposition of peroxide leads to the reaction of polymers, low molecular compounds (such as benzene and benzoic acid, etc.) are generated in rubber, which will affect the mechanical properties of rubber. Moreover, after the silicone rubber is heated in the first stage, its cross-linking density is not enough, and it must be further vulcanized to increase the density of silicone rubber. The tensile strength, resilience, hardness, swelling degree, density and thermal stability are greatly improved than that of single vulcanization. If the secondary vulcanization is not carried out, the performance of the silicone produced may be affected to a certain extent, and the products with better performance can not be obtained.