Second vulcanization is the product formed from the machine, and then the product produced by high temperature baking (180-200 degrees, generally for two hours or three hours) called 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. The parameters of primary vulcanization and secondary vulcanization may be different, which is related to the actual operation!


There are many kinds of silicone vulcanization, high temperature and room temperature. Take high temperature silicone, for example, before vulcanization is what we usually say raw rubber, mixing rubber is the many additives such as vulcanization agent, release agent and raw rubber together refining. You can see it from the outside. It breaks when you pull it with your hand. No elasticity. If the mixed rubber is vulcanized at a certain temperature, the product can be obtained, just like the silicone phone cover we usually see. As long as the manufacturer can provide food certification, it is generally non-toxic.