Nitrile Rubber Encyclopedia

Nitrile O-ring formula design

Create Date:2018-06-30 14:40:46Click volume:285
Nitrile O-ring formula design

The performance requirements of nitrile O-rings are not simple. A nitrile rubber can be used. It needs a reasonable formula design to adjust the overall performance of the nitrile O-ring to the best condition. This involves nitrile O. The vulcanization system, reinforcing filler system, softening system and anti-aging system design of the ring, because the types of vulcanizing agent, filler, softener and antioxidant all affect the oil resistance, heat resistance, and wear resistance of the nitrile O-ring. Etc., it is closely related to its sealing performance and service life.

At present, there are three kinds of vulcanization systems most commonly used in the rubber products industry, sulfur vulcanization system, peroxide vulcanization system and resin vulcanization system. Among them, vulcanized rubber vulcanized with peroxide has small compression set and good heat resistance and low temperature resistance. High scorch safety in the production process, just to meet the basic performance requirements of nitrile O-rings; However, due to peroxide curing system vulcanized rubber itself, the elongation at break is low, the curing rate is slow, the conditions allow the most Good use of DCP and sulfur together, with accelerator DM/CZ/TMTD/EZ as curing agent for the composite curing system, to further improve the overall performance of nitrile O-ring vulcanizate.

In the actual use process, the higher the general hardness of the seal ring is, the smaller the compression set, the better the sealing effect, the greater the pressure the O-ring needs to bear in the working process, the higher the hardness requirement for the rubber material; The hardness of the ring is generally divided in 60 ± 5, 70 ± 5, 80 ± 5, 90 ± 5 several levels, different pressure under different pressure nitrile O-ring hardness requirements, rubber products manufacturers can increase or reduce the amount of reinforcing agent The way to adjust the hardness of the O-ring, carbon black is the most commonly used reinforcing agent. Generally, the nitrile rubber compound reinforced with spray carbon black and thermal cracking carbon black has small compression set, low heat generation, and large contact pressure; high-hardness O-ring requires high wear-resistance carbon black and semi-reinforcing carbon Black, etc., can significantly increase the hardness of nitrile O-rings by increasing the amount of reinforcing carbon black or using appropriate oligomers of vinegar and magnesium methacrylate as hardeners.

Nitrile rubber is a typical polar rubber, so it is necessary to use a plasticizer in the softening system to reduce the interpolar molecular forces, thereby improving the process performance and physical properties of the nitrile rubber compound; the flow of the plasticizer to the rubber compound The properties of hardness, hardness, and tensile stress have certain influences. Dibutyl sebacate, dibutyl phthalate and dioctyl phthalate have little effect on the physical and mechanical properties of the rubber compound. It is the most commonly used ester plasticizer in the production of nitrile O-rings.

Anti-aging agent MB is a non-polluting type of anti-aging agent that has a significant inhibitory effect on air aging. Anti-aging agent RD has excellent protective effect against aging caused by hot oxygen. Anti-aging agent 4010 is caused by ozone, wind erosion and mechanical stress. High-efficiency anti-aging agent with remarkable fatigue protection effect, anti-aging agent 4010NA has good dispersibility and low toxicity. Anti-aging agent A belongs to general-purpose anti-aging agent, and can also be used in the production of reclaimed rubber products; the above-mentioned anti-aging agent is not easy to be extracted during work, it is Ding The anti-aging agent commonly used in nitrile O-rings can be selected in various applications to meet the protection needs of different occasions.

When a rubber product manufacturer adds an appropriate amount of nitrile reclaimed rubber to the nitrile O-ring seal formulation to reduce the production cost, it is necessary to adjust the seal ring product formulation in time, especially the vulcanizing agent, accelerator, and reinforcing agent in the formulation. The amount of anti-aging agent should not be used to save the quality of the rubber seal or reduce the production cost at the cost of quality. There are many recipe design tips for nitrile O-rings, and Xiaobian expects you to have better suggestions.