EPDM reclaimed rubber has the basic performance characteristics of EPDM rubber, excellent aging resistance such as heat resistance, ozone resistance, weather resistance, etc., and is widely used in the production of various heat-resistant rubber products, such as heat-resistant rubber hoses, heat-resistant rubber plates, heat-resistant conveyor belts, etc., which effectively reduce the cost of raw materials on the premise of ensuring the heat-resistant performance of finished products. When using EPDM reclaimed rubber as the main raw material to produce heat-resistant rubber products, a reasonable selection of compounding agents can further improve the comprehensive performance of heat-resistant rubber products and prolong the service life.
1. EPDM reclaimed rubber heat-resistant rubber vulcanization system compounding agent selection skills
The vulcanization system of heat-resistant rubber needs to ensure that a sufficient number of stable cross-linking networks can be formed, the larger the bond energy, the better the heat resistance of vulcanized rubber, the slower the oxygen absorption speed, and the better the thermal and oxidative aging resistance of EPDM reclaimed rubber vulcanized rubber. When using EPDM reclaimed rubber to produce heat-resistant rubber products, it is recommended to use a peroxide vulcanization system, or an effective vulcanization system or sulfur donor with a low sulfur dosage.
When EPDM reclaimed rubber heat-resistant rubber material is vulcanized with peroxide, the crosslinking speed and degree of crosslinking can be improved with a cross-linking agent, and then the hardness, tensile stress, tensile strength and other indexes of the rubber compound can be improved. Appropriately reduce the amount of peroxide to avoid excessive cross-linking affecting the tearing performance of the compound. A small amount of sulfur can also be used in the EPDM reclaimed rubber peroxide vulcanization system to improve the retention rate of tearing elongation after thermal and oxidative aging of the rubber.
2. EPDM reclaimed rubber heat-resistant rubber softening system compounding agent selection skills
In actual production, the smaller the molecular weight of the softener, the larger the amount of mixing, or the worse the compatibility with rubber, the worse the heat resistance of the rubber compound, and the increase of the hardness and elongation of the vulcanized rubber after heat aging are obvious. When using EPDM reclaimed rubber as the main raw material to produce heat-resistant rubber products, the high temperature aging resistance of paraffin hydrocarbon oil is better than that of naphthenic oil and aromatic hydrocarbon oil, and it is recommended to use high flash point paraffin oil; If necessary, liquid ethylene propylene rubber, polybutylene, etc. can also be used as plasticizers, and vulcanized rubber has better heat resistance.
3. EPDM reclaimed rubber heat-resistant rubber anti-aging system compounding agent selection skills
The rational use of antioxidants in the production of EPDM reclaimed rubber products can effectively inhibit the process of thermal and oxidative aging, and the commonly used heat-resistant antioxidants include free radical scavengers such as antioxidant RD/BLE/264, which are used in combination with a small amount of antioxidant MB, such as antioxidant RD and antioxidant MB, and EPDM reclaimed rubber vulcanized rubber has better heat resistance. It should be noted that in EPDM reclaimed rubber with peroxide vulcanization, free radical scavengers may affect vulcanization, especially phenylenediamine vulcanizing agents.
4. EPDM reclaimed rubber heat-resistant rubber reinforcing filling system compounding agent selection skills
When EPDM reclaimed rubber produces heat-resistant rubber products, medium or low reinforcing carbon black, such as N550/N774, is mostly selected, and the heat resistance of vulcanized rubber is better. The use of heat-resistant inorganic fillers such as talcum powder and calcined kaolin E4LYY730 replace part of the carbon black can further improve the heat resistance of the rubber compound. Metal oxides such as zinc oxide, magnesium oxide, and antimony oxide can not only improve the heat resistance of the rubber compound, but also improve the thermal conductivity of the rubber compound, and can also be used as a filler to produce heat-resistant EPDM reclaimed rubber products.
When using EPDM reclaimed rubber to produce heat-resistant rubber products, rubber product manufacturers also need to reasonably choose EPDM reclaimed rubber and EPDM original rubber, reasonably control the glue content of the formula, and ensure the heat resistance of the rubber.
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