Characteristics of EPDM sealing strip

1. Low density and high filling: EPDM is a kind of low density rubber with a density of 0.87. In addition, a large amount of oil can be filled and fillers can be added, which reduces the cost of rubber products and makes up for the high price of the original EPDM. In addition, for EPDM with high Mooney value, the physical and mechanical properties of high filled EPDM will not be significantly reduced.

2. Aging resistance: EPDM has excellent weather resistance, ozone resistance, heat resistance, acid and alkali resistance, water vapor resistance, color stability, electrical performance, oil filling and room temperature fluidity. EPDM products can be used for a long time at 120 ℃ and for a short time or intermittently at 150-200 ℃. Adding appropriate antioxidants can increase the service temperature. EPDM crosslinked with peroxide can be used under worse conditions. When the ozone concentration is 50 × The tensile strength is 30% and the fracture time is no more than 150 hours at 10 ~ 30 ℃.

3. Corrosion resistance: due to the lack of polarity and low unsaturation of ethylene propylene rubber, it has good corrosion resistance to various polar chemicals, such as alcohol, acid, alkali, oxidant, refrigerant, detergent, animal and vegetable oil, ketone, grease, etc; But in aliphatic and aromatic solvents (such as gasoline, benzene, etc.) and mineral oil. Under the long-term action of concentrated acid, the performance will also decline. In isotr7620, data on the effects of nearly 400 corrosive gases and liquid chemicals on various properties of rubber were collected. There are more than 80 kinds of chemicals with the action degree of primary ethylene propylene rubber, which are not listed here one by one.

4. Water vapor resistance: EPDM has excellent water vapor resistance and excellent heat resistance. In the superheated steam at 230 ℃, the appearance has not changed after nearly 100 hours. Under the same conditions, the appearance of fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, nitrile rubber and natural rubber deteriorated significantly in a short time.

5. Hot water resistance: EPDM also has good heat and water resistance, but it is closely related to the vulcanization system used. After soaking in 125 ℃ superheated water for 15 months, the mechanical properties of ethylene propylene rubber vulcanized with dimethylmorpholine dithiocarbamate and TMTD changed little, and the volume expansion rate was only 0. Electrical properties: EPDM has excellent electrical insulation and corona resistance, and its electrical properties are better than or close to styrene butadiene rubber, chlorosulfonated polyethylene, polyethylene and cross-linked polyethylene.

6. Elasticity: there is no polar substituent in the molecular structure of EPDM, the molecular cohesion energy is low, and the molecular chain can maintain flexibility in a wide range, which is second only to natural rubber and CIS polybutadiene rubber. It can still maintain flexibility at low temperature.