How to set the vulcanization modification of silica gel products?

2020/12/8 18:22:34

The vulcanization reaction of silicone rubber is based on vulcanization temperature, which directly affects the vulcanization speed and quality of products. With the increase of vulcanization temperature, the crosslinking reaction speed of silicone rubber molecules is accelerated and the production efficiency is improved. The lower the temperature, the slower the reaction speed and the lower the production efficiency. The type and vulcanization system of silicone rubber determine the vulcanization temperature.

When the temperature is low, the vulcanization effect is better, but it will affect the product yield, because the lower the temperature, the slower the reaction speed and the lower the production efficiency. On the contrary, high temperature will improve production efficiency, while too high temperature will lead to coking, embrittlement, edge removal and other problems, which will affect the physical and mechanical properties of silicone rubber products. Therefore, the temperature and vulcanization time are fixed in the production process, and the enterprise pays attention to the product quality as well as the product yield. Therefore, before the new mold is put into production, it will try to determine the most reasonable vulcanization temperature to improve the production efficiency and quality.

Mixed rubber mixing can only be used after adding vulcanizing agent and rubber mixing film, and it is generally better to use it immediately. Silicone rubber compound added with vulcanizing agent will volatilize slowly during the storage period. Silicone rubber compound added with sulfur can only be stored for about 15 days in summer, 1 month in spring and autumn and 2-3 months in winter. However, the vulcanized silicone rubber will be stored for a long time due to the gradual volatilization of the vulcanizing agent in the vulcanization process, so it is best to cure it immediately.

Therefore, is it best to mix silica gel and put it into use immediately? Actually, this is not the case. Silica gel and rubber mixing are only freshly mixed rubber, and the surface of the material is still hot. If it is used immediately, white spots and scorched edges will appear. Before use, the silicone rubber compound should be cooled to normal temperature before use, which is the best vulcanization time of silicone rubber compound, the shortest vulcanization time and the lowest scrap rate of products. When conditions permit, the refined silica gel can be stored in an air-conditioned room, and it is better to use up the refined materials on the same day.

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