O-rings are seals with a circular cross-section. They feature a simple structure and a wide range of specifications, and there is currently strong market demand for them. Today, we will briefly introduce key knowledge about their processing technology, hoping to help you gain a deeper understanding of O-rings.
The sealing performance of O-rings is a concern not only for users but also for manufacturers. Their quality primarily depends on dimensional precision and the quality of the rubber used. During processing, the rubber must possess specific properties: sufficient mechanical strength, tear resistance, heat resistance, oil resistance, and corrosion resistance. Moreover, when in use, it should exhibit low compression set under specific working conditions.
Based on the application requirements of different processes, selecting the appropriate rubber material is essential during O-ring processing. Most application scenarios require heat resistance and oil resistance, so nitrile rubber (NBR) is the most commonly used material.
Some application processes involve relatively high temperatures. For instance, in high-temperature environments ranging from 150°C to 190°C, acrylic rubber (ACM) is suitable. If higher temperature resistance is required, materials such as fluororubber (FKM) or silicone rubber (VMQ) can be used.
During production, when the required working pressure is relatively high, the pressure resistance of O-rings can be enhanced by increasing the rubber's hardness. The simplest method is to increase the carbon black filling amount; however, excessive filling should be avoided. Otherwise, it will make the mixing process difficult and even damage the basic physical properties of the vulcanized rubber, leading to rubber scorching.
During processing, if the same type of rubber (e.g., nitrile rubber) is used, a peroxide vulcanization system or a high-efficiency sulfur vulcanization system can be adopted to improve the O-ring's heat resistance and oil resistance while reducing its compression set. Both of these vulcanization systems generate more carbon-carbon cross-linked structures and monosulfide cross-linked structures, thereby enhancing the O-ring's performance and service life.
Understanding O-ring processing technology not only helps manufacturers improve production quality and efficiency but also enables users to make informed purchasing decisions.