Three factors to consider when choosing accelerator
1. Vulcanization flatness
Accelerator should make the rubber during the most suitable vulcanization period has a wide vulcanization flat curve, in other words, the performance of vulcanized rubber during this time should not show significant changes, which is particularly important for thick and solid rubber products. Rubber is a bad conductor of heat, vulcanized rubber material surface and internal heat is not consistent, broad vulcanization flatness is to avoid sulfur and make the product parts of the guarantee of even vulcanization.
2. The dispersion
The promoter with poor dispersion performance in the rubber material not only needs a long mixing time, increases the power consumption of the equipment, but also often leads to uneven vulcanization of products due to uneven mixing. Generally, the low melting point accelerator in the glue is easy to melt diffusion, so good dispersion. For high melting point accelerator, it is best to use small particle size powder products. For some promoters that are difficult to disperse, they can be used as master rubber.
3. Spray frost
The spray frost of the mixing compound will cause poor adhesion in the later process and reduce the appearance quality of the final product, so it should be avoid. Accelerator spray is related to the compatibility of the accelerator with the rubber. Non-polar epdm is easy to spray, but polar NBR and neoprene are difficult to spray. In the promoters, especially the promoters TMTD and ZDMC will miscible with the rubber, which will cause the spray. The compatibility of ZDEC with ZDBC and rubber is better than TMTD and ZDMC, and the spray is less.