Three factors to consider when choosing an accelerator:

1. Vulcanization flatness

The accelerator should make the rubber have a wide vulcanization flat curve during the most suitable vulcanization period, that is, the properties of the vulcanized rubber should not change significantly during this period, which is especially important for thick rubber products. Rubber is a poor conductor of heat, the surface of the vulcanized rubber material is inconsistent with the internal heat, and the broad vulcanization flatness is the guarantee to avoid sulfur and make the vulcanization of the product parts uniform.

2. Dispersion

Accelerators with poor dispersion properties not only require a long mixing time in the rubber compound, which increases the power consumption of the equipment, but also often lead to uneven vulcanization of the product due to uneven mixing. Generally, the low melting point accelerator in the glue is easy to melt and diffuse, so the dispersibility is good. For high melting point accelerators, small particle size powder products are preferred. For some hard-to-disperse accelerators, it can be used as a masterbatch.

3. Frosting

The frosting of the mixture will cause poor adhesion in the subsequent process and reduce the appearance quality of the final product, which should be avoided as much as possible. Accelerator spraying is related to the compatibility of the accelerator with the rubber. Non-polar EPDM is easy to spray, while polar nitrile and neoprene are difficult to spray. Among the accelerators, especially the accelerators TMTD and ZDMC are miscible with rubber, causing spraying. The compatibility of ZDEC with ZDBC and rubber is better than that of TMTD and ZDMC, and the spraying amount is less.