Why do silicone products need secondary curing?

- Sep 25, 2019-

Anyone who has been in contact with the silicone industry knows the process of secondary vulcanization. Specifically, it refers to the silica gel product that has been prepared by mixing high-pressure pressure molding after adding some additives to the silica gel, and then putting the product into a special oven. 180 degrees - 200 degrees 2-3 hours of baking, this process is called secondary vulcanization, then why do this secondary vulcanization, what is the role?

The role of secondary vulcanization, when the silica gel is vulcanized with peroxide, the decomposition of the peroxide initiates the reaction of the polymer to form low molecular compounds such as benzene and benzoic acid. The presence of silica gel will affect the mechanical properties of the silica gel, and the silica gel is not sufficiently associated in the oil-forming stage. It is necessary to undergo secondary vulcanization to increase the density, tensile strength, elastic hardness and swelling degree of the silica gel. If the performance of the secondary vulcanized silica gel is not affected, a product with better performance cannot be obtained. Secondary vulcanization may vary depending on the product parameters, which is related to different products.