Vulcanization system for rubber seals
The rubber vulcanization system is a vital part of the rubber industry, which transforms the rubber from a soft and viscous initial state to a rubber product with excellent characteristics such as elasticity and wear resistance by initiating the cross-linking reaction between the rubber molecular chains. The selection and design of the vulcanization system directly affects the performance, service life, and production efficiency of rubber products. This article will introduce the characteristics, applicable rubber grades, and application fields of each vulcanization system in detail, to help readers better understand the process and selection of rubber products.
Traditional sulfur vulcanization system
Features: The traditional sulfur vulcanization system is the oldest and most widely used rubber vulcanization method. It makes the rubber have strong elasticity and tensile strength by adding sulfur, which reacts chemically with rubber molecules at the right temperature and pressure to form cross-linked bonds. The amount of sulfur added is usually 1.5-3.0 parts per 100 parts rubber (PHR), and the vulcanization temperature is generally controlled at 140-160 °C.
Applicable rubber types: natural rubber (NR), styrene-butadiene rubber (SBR), butadiene rubber (BR), and nitrile rubber (NBR).
Applications: Because the traditional sulfur vulcanization system can greatly improve the physical properties of rubber, especially abrasion resistance, fatigue resistance, and elasticity, it is widely used in the manufacture of various tires, shoe soles, conveyor belts, shock-absorbing parts, and other products. In the case of tires, about 300 million tires are produced globally every year using traditional sulfur curing systems.
Advantages: The traditional vulcanization system has the advantages of simple operation and low cost, and is suitable for large-scale industrial production. At the same time, it can provide a long service life and good physical properties for the products. Therefore, although a variety of new vulcanization systems have emerged, the traditional sulfur vulcanization system still occupies an important position in the rubber industry.
Peroxide vulcanization system
Features: The peroxide vulcanization system is to achieve cross-linking of rubber by adding peroxide (such as cumene peroxide DCP) as a vulcanizing agent. This system does not require the involvement of sulfur and is usually cured at 160-180°C, making it suitable for special rubber materials that require high-temperature vulcanization. Peroxide vulcanization can significantly improve the heat, oil, and aging resistance of rubber.
Applicable rubber types: Ethylene propylene rubber (EPDM), silicone rubber (Si), fluorine rubber (FKM), neoprene rubber (CR), and polyolefin rubber.
Application field: The Peroxide vulcanization system is mainly used in rubber products with high requirements for high-temperature resistance and chemical corrosion resistance. For example, this vulcanization system is commonly used in cable jackets, seals, and oil- and heat-resistant parts in automotive engines. In particular, ethylene propylene diene monomer (EPDM), has excellent weather and heat resistance, and about 30% of the EPDM rubber consumed globally each year is produced by peroxide vulcanization.
Advantages: Compared with the traditional sulfur vulcanization system, peroxide vulcanized products have better-aging resistance and can maintain stable performance in long-term high temperature or strong corrosive environments. This makes peroxide vulcanization systems an important position in the aerospace, automotive, and high-end manufacturing industries.
