Secondary vulcanization, the English name is (postcure), is the product formed from the machine, and then the produced product is baked in the oven for a period of time (180 degrees to 200 degrees, usually two or three hours). ), called the second vulcanization.

Secondary vulcanization is also called post vulcanization. Commonly used for silicone rubber, fluororubber and fluorosilicone rubber vulcanization.

The role of secondary vulcanization: When the silicone rubber is vulcanized with peroxide, after the decomposition of the peroxide causes the polymer reaction, low molecular compounds (such as benzene and benzoic acid) are formed in the rubber, which will affect the mechanical properties of the rubber. Moreover, after the silicone rubber is heated and formed in the first stage, its cross-linking density is not enough, and the density of the silicone rubber can be increased by further vulcanization reaction. The tensile strength, resilience, hardness, swelling degree, density, and thermal stability are all better than one The vulcanization has been greatly improved. If the secondary vulcanization is not carried out, the performance of the produced silica gel may be affected to a certain extent, and a product with better performance cannot be obtained. The parameters of the primary vulcanization and the secondary vulcanization may be different, which is different from the actual Operation related!

There are many kinds of silica gel vulcanization, high temperature and room temperature. Take high-temperature silica gel as an example. Before vulcanization, it is what we usually call raw rubber. Mixed rubber is made by refining many additives such as vulcanizing agent, mold release agent, etc. together with raw rubber. It can be seen from the appearance. It breaks as soon as it is pulled by hand, and there is no elasticity. If the mixed rubber is vulcanized and formed at a certain temperature at a certain temperature, a product can be obtained, just like the silicone mobile phone cases we usually see.