EPDM has excellent high temperature resistance and can be used to consume radiator hoses; Adding an appropriate amount of EPDM reclaimed rubber in EPDM radiator hose can reduce raw material cost and consumption cost; However, in the process of application, many EPDM radiator rubber tubes will produce material accumulation on the inner wall, forming the blockage of heat dissipation pipes; Among them, manufacturers who use EPDM reclaimed rubber to consume radiator hoses think that the reclaimed rubber itself contains impurities, but is this really the case?
1. Reasons for material accumulation of heat dissipation hose

Whether EPDM rubber hose contains EPDM reclaimed rubber or does not contain EPDM reclaimed rubber, material accumulation may occur on the surface of the inner wall. This is because when vulcanizing EPDM rubber compound with sulfur vulcanization system, zinc oxide, stearic acid or zinc salt accelerators are usually used together. Soluble zinc salt is the main factor to form material accumulation on the inner wall of the rubber hose; The accelerator with low solubility in the vulcanization system will also promote the accumulation of materials on the inner wall of the hose; Many EPDM heat dissipation hoses are filled with a large number of mineral fillers, which will also promote the formation of accumulated substances.

2. Methods to reduce material accumulation on the inner wall of heat dissipation hose

Whether EPDM heat dissipation hose can produce material accumulation is directly related to the extraction of rubber by coolant. The experiment shows that the extract content of ethylene propylene diene monomer rubber / reclaimed rubber vulcanizate cured with peroxide is only 10% of sulfur vulcanizate. At this time, the extract content in the coolant is greatly reduced, and the probability of material accumulation on the inner wall of the hose and obstructing the normal operation of the cooling system is naturally greatly reduced.

Therefore, when using EPDM or EPDM reclaimed rubber to consume radiator hoses, peroxide vulcanization can be selected. When sulfur vulcanization is necessary, it is best to use an effective vulcanization system with low sulfur consumption, which can not only reduce the accumulation of materials on the inner wall of the hose, but also improve the heat resistance, compression resistance and permanent deformation of the rubber; However, in the process of practical operation, peroxide is easy to be affected by oxygen when steam vulcanizing EPDM compound, resulting in poor hot tearing performance of the compound. Therefore, special attention is required during vulcanization molding.

Xiaobian can't say that the accumulation of substances on the inner wall of the radiator hose consumed with EPDM reclaimed rubber has nothing to do with the integrity of EPDM reclaimed rubber. After all, if the quality of the reclaimed rubber you use has its own problems, it's useless to say anything; However, when choosing high-quality EPDM reclaimed rubber to replace local EPDM consumption radiator hose, the accumulation of substances on the inner wall of the hose really has nothing to do with the reclaimed rubber; Therefore, when using reclaimed rubber to reduce costs, we must go to the right manufacturer to choose reclaimed rubber with relevant testing specifications.