(1) Improper formulation design, imbalanced configuration of vulcanization system, excessive amount of vulcanizing agent and accelerator.

(2) For some types of rubber that require plasticization, the plasticization does not meet the requirements, the plasticity is too low, and the gum is too hard, resulting in a sharp temperature rise during the plasticization. The temperature of the roller of the rubber mill or other roller device (such as the remelter and the calender) is too high, and the cooling is not enough, which may also cause scorch on the spot.

(3) When the compound is unloaded, the film is too thick, the heat is not good, or it is stored in a hurry without cooling. In addition, factors such as poor ventilation and high temperature in the warehouse cause heat accumulation, which will also cause scorch.

(4) Poor management during rubber storage. After the remaining scorch time has elapsed, it is still stacked and unused, resulting in natural scorch. Difficult processing; affecting the physical properties of the product and the smoothness and smoothness of the outer surface; it may even lead to disconnection at the joints of the product.