The so-called coke burning, is refers to the addition of vulcanizing agent mix in the process of processing or parking in the early vulcanization phenomenon, also known as from sulfur, its nature is vulcanization, rubber partial crosslinking.After burning, plastic material flow is obviously poor, or can not flow, no longer have processing capacity.
The viscosity (fluidity) of the minimum torque reactive glue during the coke burning period is high or low;The length of l interval during coke burning reflects the processing safety of glue materials.
1. Causes of coke burning
(1) promote the selection of inappropriate;
(2) processing temperature is too high;
(3) insufficient cooling;
(4) processing time is too long;
(5) the dispersing agent is not uniform.
2. Factors affecting the duration of coking
(1) promoters of varieties: sulfonamides promoters char time is long, thiuram class, dithiocarbamate promoters char time is very short;
(2) temperature: the higher the processing temperature or parking temperature, the more prone to coke phenomenon;
(3) processing time: the longer the time, the more easily burnt
(4) with the agent: ZSJ with the dispersing agent is not uniform, auxiliary local concentration will speed up the curing speed caused by local coke.
3. Measures to prevent coke burning
(1) the use of tardive promoters, such as sulfonamide promoters.
(2) the processing temperature, control of the masterbatch usually in the exhaust temperature of 165 ℃, the highest do not exceed 180 ℃;H rubber mixing line glue temperature generally does not exceed 105 ℃, the highest do not exceed 110 ℃.
(3) cooling fully before folding parking, storage temperature generally under 45 ℃, the highest do not exceed 50 ℃.
(4) in the case of dispersion to ensure that the agent, try to shorten the processing time.
(5) use anticoking agents such as CTP.