EPDM rubber has excellent elasticity, mechanical properties and electrical properties, and is excellent in heat resistance, weather resistance, ozone resistance and chemical resistance. It is widely used in the automotive industry, electrical and electronic industry, tape, sponge products and tire industry. The production formula and production process of Yuan E-propylene rubber products are very different, but they cannot circumscribe the basic processing technology of EPDM rubber products. Xiaobian today and everyone summarize the process elements of the production of rubber products from EPDM rubber.
1. Key points of rubber mixing
EPDM rubber is a kind of ethylene-propylene rubber. Its process performance is similar to that of ethylene-propylene rubber. The processing technology is good. When mixing, you can choose general mixing method or reverse mixing method. It is worth noting that With the continuous advancement of reclaimed rubber production technology, many EPDM rubber products have begun to use EPDM reclaimed rubber. When EPDM/Recycled rubber is used together, the excellent EPDM reclaimed rubber itself has fluidity and plasticity. Better than the original glue, it is best to add the reclaimed rubber after plasticizing the EPDM rubber for a period of time.
2. Key points of vulcanization: The side chain of EPDM rubber contains unsaturated double bonds, and the vulcanization performance is better than that of ethylene propylene rubber (the binary ethylene propylene rubber can only choose peroxide vulcanization), which can choose sulfur and promote For the curing system of the agent, it is also possible to try the vulcanization and crosslinking of the peroxide and the resin; wherein the acidic compounding agent (such as the groove black) affects the peroxide vulcanization process, and it must be used with caution.
3. Reinforcement filling
EPDM rubber is an amorphous elastomer. When it is crystallized during stretching, reinforcing fillers such as carbon black, silica, silicate, calcium carbonate, etc. must be used to improve the comprehensive index of EPDM rubber products. EPDM rubber has a low density. In theory, rubber filler and rubber oil can be filled in a large amount to reduce the cost. However, a large amount of rubber filler or rubber oil will significantly reduce the mechanical properties of rubber products; therefore, more rubber products manufacturers are willing to Replacing part of EPDM with an appropriate amount of EPDM reclaimed rubber to reduce the production cost of EPDM rubber products.
4. Softening and plasticizing: In the production process of EPDM rubber products, low-polarity and less volatile substances are generally selected as plasticizers such as paraffinic oil or naphthenic oil; EPDM products with particularly high viscosity requirements also need to cooperate. A non-reactive phenolic resin such as an alkyl phenol resin is used as the crepe adhesive.
5. Rubber and use
In order to improve the comprehensive performance of rubber products, a single rubber can not meet the demand of rubber products. Among them, EPDM rubber can be used together to improve the comprehensive performance of butyl rubber in butyl rubber products. It can also be combined with natural rubber and styrene-butadiene rubber. The use of unsaturated rubber such as nitrile rubber and neoprene rubber can improve the ozone resistance and chemical resistance of EPDM rubber products; or it can be used together with polypropylene plastic to improve process performance and practicability.
At present, the main production mode of EPDM rubber is EPDM rubber + EPDM reclaimed rubber. The molecular structure of EPDM rubber and EPDM reclaimed rubber is different. When designing rubber products and setting process conditions Be careful.