The high temperature vulcanized silicone rubber sealing strip of Kunshan corrugated box manufacturer is a sealing strip made of a new type of material. The eva material processing mainly uses methyl vinyl raw rubber as the base material, adding reinforcing fillers, infiltration agents (structure control agents), others Additives, cross-linking agent color masterbatch are formulated into compound rubber, which is extruded through a rubber extruder vulcanized into a high temperature drying tunnel.

Raw rubber: eva foam with a polymerization degree of 5000-8000, a vinyl content of 0.03%-0.3%; filler: fumed silica, precipitation silica, diatomaceous earth, quartz powder, etc.; structure control agent: hydroxyl Silicone oil, silazane, diphenyl silicon diol, etc.; the bond energy of the Si—O bond of the main chain of methyl vinyl siloxane is 444KJ/mol, which is higher than the C—C bond energy of the main chain of ordinary organic polymers (356 KJ /mol), C—O bond energy (339KJ/mol), which makes high temperature vulcanized silicone rubber sealing strips have better aging resistance, high resilience, high low temperature resistance than other traditional sealing strips.

1. Reaction mechanism of high temperature vulcanized silicone rubber sealing strip

The cross-linking reaction of high-temperature vulcanized silicone rubber sealing strips can be divided into peroxide-initiated reaction hydrosilylation reaction according to the type of cross-linking agent. The peroxide-initiated reaction is the decomposition of organic peroxides to generate free radicals. Free radicals attack the methyl vinyl groups on the side groups of the siloxane to cause a chain reaction cause crosslinking. The hydrosilylation reaction is a cross-linking reaction between the vinyl groups on the side groups of the siloxane the cross-linking agent of the silicon hydride under the catalysis of the platinum complex.

2. Excellent features of high temperature vulcanized silicone rubber sealing strip 

2.1 Excellent weather resistance aging resistance. The bond energy of eva foam material is higher than the ultraviolet radiation energy (370KJ/mol), so the silicone rubber will keep the main chain breaking under long-term exposure to sunlight ozone, its performance will be significantly reduced. Make the silicone rubber sealing strip have a longer service life. 

2.2 Excellent high low temperature resistance. Silicone rubber can be used for a long time in the temperature environment of -60～200℃. The wide operating temperature range enables silicone rubber sealing strips to maintain good performance in cold areas at high latitudes hot areas at low latitudes. 

2.3 Good resilience. The Si—O bond in silicone rubber has low rotational energy siloxane has a spiral chain structure. Therefore, silicone rubber has good resilience, so that the silicone rubber sealing strip will return to its original shape after being deformed by an external force to ensure its sealing. performance. 

2.4 Safety environmental protection. Silicone rubber is physiologically inert, non-toxic tasteless, does release volatile gases during use. It is widely used in the food pharmaceutical industries. In the US FDA certification, so far, silicone rubber is the most harmless material to the human body among all the new environmentally friendly materials. 

2.5 Kunshan corrugated box manufacturer selective permeability. According to research, the oxygen permeability of silicone rubber is 25 times that of natural rubber 428.6 times that of butyl rubber; the permeability of silicone rubber to harmful gases such as sulfur dioxide is lower than other rubbers. This performance can keep fresh air in the room, which is most suitable for people's life. 

2.6 The surface is smooth the colors are diverse. The surface of the silicone rubber is hydrophobic clean, various colors can be adjusted, which has a good decorative effect. 

3. Application of high temperature vulcanized silicone rubber sealing strip

In recent years, as a new type of rubber material, silicone rubber has shown unparalleled superior performance in many fields, playing the role of dustproof, waterproof, fixing, sound insulation, heat insulation, shock absorption, sealing decoration, etc., is widely used It is used in the fields of construction, automobile, aerospace, medical health, communication power, transportation, household appliances, etc.

4. Prospects for high temperature vulcanized silicone rubber seals

Silicone rubber sealing strips have yet been widely promoted due to price market awareness. Compared with other rubber sealing strips, the excellent performance indicators of silicone rubber sealing strips are more suitable for the low-carbon building energy-saving doors windows that the country vigorously advocates, are more in line with the green environmental protection needs of modern life. Other raw materials for plastic rubber seals are derived petroleum cracking products, while silicone rubber is derived silicon ore, which is more sustainable. With the advancement of science technology the reduction of use cost, it is a general trend that silicone rubber sealing strips replace other rubber sealing strips.