Rubber vulcanization means that the raw rubber containing sulfur is heated and pressurized, and the sulfur and raw rubber will undergo a chemical reaction. The rubber molecules are cross-linked and become a network structure. Rubber vulcanization temperature is the basic condition for rubber to undergo vulcanization reaction (crosslinking reaction), which directly affects rubber vulcanization speed and product quality.
With the increase of room temperature vulcanizate and the emergence of high temperature vulcanization, the vulcanization temperature tends to two extremes. From the perspective of improving the curing efficiency, it should be considered that the higher the curing temperature, the better, but in reality, the curing temperature cannot be increased infinitely. Rubber is a high-molecular polymer. High temperature will cause a cracking reaction of the rubber curing oven, which will cause the cross-linking bond to break, that is, the phenomenon of "vulcanization back to original" will occur, thereby reducing the physical and mechanical properties of the vulcanizate. For example, when vulcanizing natural rubber at high temperature, the oxygen dissolved in the rubber increases in activity as the temperature increases, causing strong oxidation, destroying the rubber structure, and reducing the physical and mechanical properties of the vulcanizate.
The change of vulcanization temperature will affect the vulcanization reaction speed of rubber. For every 10 ° C increase in vulcanization temperature, the vulcanization speed can shorten the vulcanization time by half. Properly increasing the vulcanization temperature can speed up the vulcanization speed and improve production efficiency.
Although the vulcanization temperature can improve production efficiency, the vulcanization temperature should not be too high, because when the temperature is too high, the oxidation reaction of the rubber will intensify, which will reduce the aging resistance of the rubber product. The fibrous substance added in some rubber products will be destroyed after being exposed to high temperature, which will greatly reduce the strength of the product. At the same time, because the thermal conductivity of rubber is very poor, it is difficult to make the product reach high temperature uniformly.