Sealing material manufacturers tell you that the current development trend is to gradually develop the injection pressure method, but due to their different adaptation scope, the coexistence and development of the three is still a reality. According to its characteristics, the main forming method of O-ring is plate molding.
In the process of molding vulcanization, the curing temperature, time and pressure must be controlled strictly and correctly, and the change of temperature and other parameters during the curing process must be paid attention to at any time, and corresponding treatment should be carried out, otherwise the product will be short of sulfur or over sulfur. If the automatic control system is used, the whole curing process will be automatically recorded and controlled to ensure that the product reaches the positive curing degree.
Vulcanization temperature is one of the basic conditions for rubber O-shape vulcanization reaction, which directly affects the vulcanization speed and product quality. High curing temperature, fast curing speed and high production efficiency; low curing temperature and slow curing speed. The most suitable curing temperature of natural rubber is 143 ℃ -- 150 ℃, and that of synthetic rubber is 150 ℃ ~ 180 ℃. The curing time is usually determined according to the determined curing temperature, and the curing time is determined by test.
The purpose of pressurizing rubber products during vulcanization is to make the compound flow easily and fill the mold cavity, prevent bubbles during vulcanization and improve the compactness of products. The vulcanization pressure depends on the rubber hardness and mold size. When the rubber hardness is high and the mold size is large, the pressure can be higher, otherwise, the pressure should be appropriately reduced.