Technical requirements for silicone sealing rings:
High temperature vulcanized silicone rubber is a type of high molecular weight (usually between 400000 and 800000) polyorganosiloxane (i.e. raw rubber) that uses organic peroxides as curing agents and additives such as reinforcing fillers. Pressure forming (molding, extrusion, rolling) or injection molding, and entering the rubber at a high temperature chain. This type of rubber is commonly referred to as silicone rubber.

The vulcanization of high-temperature vulcanized silicone rubber is generally divided into two stages. The first stage is the mixing of silicone rubber, reinforcing agent, additive, curing agent, and structural control agent, and then heating and vulcanizing under metal mold pressure. The pressure is about 50kg/cm2, the temperature is 120, 130 ° C, and the time is 10 minutes. The second stage is to remove the silicone rubber from the mold, place it in an oven, and bake at 200 ° C for several hours to 24 hours. Further vulcanization of rubber and decomposition and volatilization of organic peroxides.

Silicone rubber filler is a type of silicone rubber that can increase the strength of vulcanized rubber by ten times. The main purpose of adding various additives is to reduce the cost of rubber, improve the performance of vulcanized rubber, and make vulcanized rubber have various special properties such as flame retardancy and conductivity.

Crosslinking agents are various organic peroxides, such as benzoyl peroxide, 4-dichlorobenzoyl peroxide, dicarboxylic peroxide, 5-di-tert-butyl peroxide, etc. In order to avoid excessive mixing time and the formation of "structure", which makes the complex difficult to process and mature, structural control agents are added. Methyl hydroxy silicone oil or diphenyl dihydroxyalkanes can be used as structural control agents.

The side groups on the main chain of silicone rubber can be methyl, vinyl, phenyl, trifluoropropyl, etc. Methyl is the most commonly used, and other functional groups can also be introduced to improve processing and other properties. Therefore, based on the side groups and compound formulations of silicone rubber, different types of silicone rubber can be obtained for different purposes. There are generally the following types (containing methyl and vinyl groups), high and low temperatures (containing phenyl, methyl, and ethylene), low compression set (containing methyl and vinyl groups), low shrinkage (devolatilization), and solvent resistance (fluorosilicone rubber). The following are important types of silicone rubber.