The reason why silicone rubber products need to be vulcanized is because after vulcanization, they have higher application value, greatly improved mechanical properties, no change in adhesion, are not easy to break, have high tensile strength, and are resistant to high temperatures.

Not all require vulcanization, such as thermoplastic silicone rubber, but synthetic silicone rubber requires the use of vulcanizing agents for vulcanization.
The vulcanization of silicone rubber is divided into two stages: the first stage is to mix raw rubber, reinforcing agents, additives, vulcanizing agents, and structural control agents to obtain silicone rubber raw materials. Mix raw materials into semi-finished materials; The second stage is to put the materials and finished materials into the hardware mold for hot pressing, extrusion, extrusion, injection and other processes. The machine is subjected to force and the product is catalyzed and fixed, and the mold is formed at high temperature. The vulcanization process of silicone rubber can be divided into three methods: direct vulcanization, indirect vulcanization, and mixed gas vulcanization, depending on the vulcanization medium and vulcanization method.

1. Direct vulcanization: Put the product directly into hot water or steam medium for vulcanization.

2. Indirect vulcanization: Place the product in hot air for vulcanization, which is usually used for certain products with strict appearance requirements, such as rubber shoes.

3. Mixed air vulcanization, first using air vulcanization, and then using steam direct vulcanization. This method can overcome the drawbacks of steam vulcanization affecting the appearance of products, as well as the drawbacks of slow heat transfer, long vulcanization time, and easy aging caused by hot air.

Regarding silicone rubber, please refer to the details:
https://www.htvsilicone.com/product-high-temperature-resistance-silicone-rubber(250-)-.html