After so many years in the rubber industry, looking at all the knowledge and practical experience, I personally believe that the most difficult and complex rubber formulation and processing technology is the design of the vulcanization system.

In the category of general-purpose rubber, the selection of rubber system is not difficult to operate in the formulation design, as long as there is a certain understanding of the characteristics of several general-purpose rubbers. The same is true for the design of reinforcement systems. With a certain understanding of the commonly used carbon black and silica varieties, one can know how to apply them in the formulation design.

Vulcanization of rubber is a more figurative term, which is essentially the cross-linking of rubber molecular chains. The cross-linking of rubber is achieved by using cross-linking agents to connect adjacent linear rubber molecular chains to form a net-like structure.

The scorch time of rubber is mainly considered in terms of processing safety. In the previous diagram of the rubber vulcanization process, the scorch time is the time corresponding to the time when the rheometer torque just starts to rise significantly.

1. Choose the appropriate accelerator. Dithiocarbamate has the shortest scorch time, followed by thiazole accelerator and sub-sulfonamide accelerator with long scorch time.
2, the use of coking inhibitors. Common coking inhibitors are mainly the following three categories: A) organic acids or aldehydes; B) anti-coking agent CTP or PVI; C) sulfonamides.
3、Reduce processing heat history. The same rubber formulation, the scorch time measured after various processing heat histories is significantly shorter than the scorch time measured without processing heat histories.