EPDM reclaimed rubber has excellent high and low temperature resistance and anti-aging performance, which is an ideal raw material for replacing EPDM raw rubber in the production of heat-resistant rubber conveyor belt covering rubber, which can effectively reduce the cost of raw materials and production energy consumption on the premise of ensuring the performance of finished products. In actual production, EPDM reclaimed rubber can be used in combination with which rubber can be used to produce heat-resistant conveyor belt covering rubber? How much is appropriate? How to design the formula of rubber conveyor belt covering rubber mixed with EPDM reclaimed rubber to make the heat resistance of the finished product more beneficial?
1. EPDM rubber/EPDM reclaimed rubber and use the production of heat-resistant rubber conveyor belt to cover the rubber vulcanization formula
70 parts of EPDM rubber, 30 parts of EPDM reclaimed rubber, 4.5 parts of zinc oxide, 1 part of stearic acid, 40 parts of carbon black N330, 4.5 parts of paraffin oil, 1.8 parts of accelerator M, 1.4 parts of accelerator TMTD, 1.8 parts of sulfur; Total: 155 copies.
50 parts of EPDM rubber, 50 parts of EPDM reclaimed rubber, 4 parts of zinc oxide, 0.5 parts of antioxidant RD, 50 parts of carbon black N330, 4.5 parts of polyethylene glycol, 0.4 parts of sulfur, 4.5 parts of peroxide; Total: 163.9 shares.
2. EPDM rubber/butyl rubber/EPDM reclaimed rubber and use it to produce heat-resistant rubber conveyor belt covering rubber vulcanization formula
30 parts of EPDM rubber, 30 parts of butyl rubber, 40 parts of EPDM reclaimed rubber, 4.5 parts of zinc oxide, 1 part of stearic acid, 60 parts of carbon black N330, 18 parts of paraffin oil, 0.45 parts of accelerator M, 1 part of accelerator TMTD, 1.85 parts of sulfur; Total: 186.8 shares.
3. Heat-resistant rubber conveyor belt covering rubber mixed with EPDM reclaimed rubber vulcanization formula design
(1) Vulcanization system: heat-resistant rubber conveyor belt covering rubber requires the rubber material to have good heat resistance, and it is not easy to produce aging and cracking problems when used at higher temperatures, and generally uses peroxide vulcanization system or low sulfur vulcanization system, and sulfur and peroxide can be used together if necessary; Combining a small amount of sulfur in the peroxide vulcanized rubber compound is very beneficial to improving the retention rate of the elongation at break after the thermal and oxidative aging resistance of the rubber compound, and it is necessary to pay attention to the compression permanent deformation of the rubber compound in hot air.
(2) Softening system: the softener affects the heat resistance of EPDM rubber/reclaimed rubber compound, and the smaller the molecular weight of the softener, the larger the amount of mixture or the worse the compatibility with rubber, the worse the heat resistance of the rubber compound. When using EPDM rubber E4LYY59 and EPDM reclaimed rubber to produce heat-resistant rubber conveyor belt covering rubber, paraffin hydrocarbon oil with good high temperature aging resistance is mostly used, such as paraffin oil with high flash point; If necessary, liquid nitrile butadiene rubber, polybutylene, etc. can be added as plasticizers, and the heat resistance of the rubber material is better.
(3) Anti-aging system: use antioxidants RD, BLE, 246, etc., or use them in combination with anti-aging synergists MB, MTI, etc., and the most commonly used is antioxidants RD and MB. When EPDM rubber is vulcanized with peroxide, it is necessary to pay attention to the influence of antioxidants on the vulcanization of rubber compounds, which generally has a greater impact on phenylenediamines and less on polymerized quinolines.
(4) Reinforcing filling system: When the rubber heat-resistant conveyor belt covering rubber is mixed with EPDM reclaimed rubber, medium or medium and low reinforcing carbon black, such as N550 and N774, has better heat resistance of vulcanized rubber; Filling talcum powder and calcined kaolin are more beneficial to improve the heat resistance of ethylene propylene compound. When using silica as a reinforcing agent to improve the heat resistance of rubber compounds, it is necessary to pay attention to elastic changes. In addition, EPDM reclaimed rubber can also use metal oxides such as zinc oxide, magnesium oxide, antimony oxide and other metal oxides with good thermal stability when producing heat-resistant conveyor belt covering rubber.
When using EPDM reclaimed rubber to reduce the production cost of heat-resistant rubber conveyor belt covering rubber, rubber product manufacturers also need to appropriately adjust the production process, and the follow-up editor will continue to discuss relevant issues with you.
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