Pipeline sealing ring water (EPDM) plastic molding (injection molding)

Ethylene propylene rubber is synthesized from ethylene and propylene as the main raw materials, with outstanding aging resistance, electrical insulation performance, and ozone resistance. EPDM can be filled with a large amount of oil and carbon black, and the product price is low. EPDM has good chemical stability, and its wear resistance, elasticity, and oil resistance are close to those of SBR. Ethylene propylene rubber has a wide range of applications, including being used as tire sidewalls, rubber strips, inner tubes, and automotive components. It can also be used as wire and cable sheaths, as well as high-voltage and ultra-high voltage insulation materials. It can also manufacture light colored products such as shoes and sanitary products. What are the characteristics and functions of ethylene propylene rubber sealing rings
1. Low density and high filling ability
The density of ethylene propylene rubber is a lower type of rubber, with a density of 0.87. In addition, a large amount of oil can be filled and fillers can be added, which can reduce the cost of rubber products and make up for the high price of EPDM raw rubber. Moreover, for high Mooney value EPDM, the reduction in physical and mechanical energy after high filling is not significant.
2. Aging resistance
Ethylene propylene rubber has excellent weather resistance, ozone resistance, heat resistance, acid and alkali resistance, water vapor resistance, color stability, electrical performance, oil filling ability, and room temperature fluidity. Ethylene propylene rubber products can be used for a long time at 120 ℃, and can be used briefly or intermittently at 150-200 ℃. Adding suitable anti-aging agents can increase its usage temperature. EPDM rubber crosslinked with peroxide can be used under harsh conditions. Under the conditions of ozone concentration of 50 pphm and stretching of 30%, EPDM rubber can withstand over 150 hours without cracking.
3. Corrosion resistance
Due to the lack of polarity and low degree of unsaturation of ethylene propylene rubber, it has good resistance to various polar chemicals such as alcohol, acid, alkali, oxidant, refrigerant, detergent, animal and vegetable oil, ketone and grease; But it has poor stability in fatty and aromatic solvents (such as gasoline, benzene, etc.) and mineral oils. Under the long-term action of concentrated acid, the performance will also decrease. In ISO/TO 7620, data on the effects of nearly 400 corrosive gaseous and liquid chemicals on various rubber properties are collected, and levels 1-4 are specified to indicate their degree of action. The impact of corrosive chemicals on rubber properties is as follows:
Effect of grade volume swelling rate/% hardness reduction on performance
1 ＜ 10 ＜ 10 Slight or none
2 10-20<20 smaller
3 30-60 ＜ 30 Moderate
4>60>30 Severe
4. Water vapor resistance
Ethylene propylene rubber has excellent water vapor resistance and is estimated to be superior to its heat resistance. In superheated steam at 230 ℃, there was no change in appearance after nearly 100 hours. Under the same conditions, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, nitrile rubber, and natural rubber undergo significant deterioration in appearance in a relatively short period of time.
5. Resistance to hot water
Ethylene propylene rubber also has good resistance to hot water, but is closely related to all vulcanization systems. The mechanical properties of ethylene-propylene rubber vulcanized with morpholine disulfide and TMTD as the curing system showed little change after soaking in 125 ℃ superheated water for 15 months, with a volume expansion rate of only 0.3%.

6. Electrical performance
Ethylene propylene rubber has excellent electrical insulation performance and corona resistance, and its electrical performance is superior to or close to that of styrene butadiene rubber, chlorosulfonated polyethylene, polyethylene, and cross-linked polyethylene
7. Elasticity
Because there is no polar substituent in the molecular structure of ethylene propylene rubber, the molecular cohesion energy is low, and the molecular chain can maintain flexibility in a wide range, second only to natural rubber and cis-1,4-polybutadiene rubber, and can still maintain at low temperatures.
8. Adhesion
Due to the lack of active groups in the molecular structure of ethylene propylene rubber, the cohesion energy is low