Development Of High Performance Aramid Pulp Rubber Composite Seals

Rubber seals play an increasingly important role in the industry area. Researchers try touse different kinds of rubbers and different formulations to adjust the performance of rubberseals to suit different working conditions. Researches of special rubber formulations andprocesses and how to improve the applicability of the materials are still the focus ofdevelopment direction of the rubber seals products industry in the future.By mechanical mixing method, the solution method and physical isolation method foraramid pulp processing, through comparative study of several different aramid pulpdispersion methods. Result shows that mechanical mixing method is the worst. The effect ofthe solution method is very good, but it cost much and leads large pollution, furthermore, theprocess of the solution method is complicated. Therefore, we choose physical isolationmethod.Coupling agent can improve the degree of crosslinking of vulcanized rubber, and thecoupling agent that without sulfur can accelerate the speed of reaction of vulcanized rubber.The vulcanized rubber had obvious orientation with aramid pulp fiber. The tensile modulus ofparallel to the rolling direction of the specimen is significantly higher than that in the verticaldirection. With the addition of coupling agent, KH550has its best modification effect.However,the elongation and compression performance of Si69declined after modified.With the adding of adhesion aid, elongation and tensile strength of vulcanized rubber hasincreased. Elongation at break and tear strength increased as well.1756HS get the mostsignificant improvement in elongation. SR634has the most significant improvement in tearstrength, and the heat-proof aging of SR634is more stable.With the increase of dosage of aramid pulp, the hardness, modulus, tear strength, oilresistance of vulcanized rubber are significantly improved. Compressions set first increaseand then remain stable. Add4parts by mass of pulp vulcanized rubber,50%modulus can beincreased more than2times both in normal temperature and high temperature, but theelongation at break will follow the rapid decline. Added aramid pulp seal skeleton caneffectively increase the cylindrical sealing force retention and outer dimensions of retention.The Viton gaskets with aramid pulp added can stand up to major pressure. The performancesof high temperature resistance and high pressure resistance of products have greatly improved.Particularly suitable for high temperature and pressure sealing applications.