Silicone construction silicone sealant is mainly composed of base glue, filler, cross-linking agent, catalyst and other additives. The base rubber is the basic material of the sealing silicone rubber, which determines the performance of the sealant. The base rubber is 107 room temperature vulcanized silicone rubber. The chemical structure is hydroxyl-terminated polydimethylsiloxane. The filler is some inorganic powders, such as white carbon black, calcium carbonate, and heavy calcium. The role of the filler is to provide strength, hardness, and rheology. Performance, etc. The cross-linking agent and catalyst are the curing system of the sealant. The sealant changes from the liquid state to the elastomer through the reaction of the base rubber with the cross-linking agent and the catalyst and the moisture in the air.

 

 

The production process of silicone rubber sealant is the process of mixing the various components that make up the sealant uniformly. The usual production method is to use a kneader to mix the base material and the filler, if necessary, to grind with a grinder, and then use a planetary machine to mix the crosslinking agent, catalyst and other additives in a vacuum state.

 

 

 

Compared with other types of sealants, silicone building sealants have good elasticity, high temperature resistance and low temperature flexibility, and have good weather resistance, ozone resistance, and UV resistance. The cost is relatively high, it is usually a bit more expensive than other types of sealants, and the strength, especially the tear resistance, is poor. Some data have introduced that the water resistance is worse than polyurethane sealants, and the oil resistance is not as good as polysulfide sealants.

 

 

Construction sealants can be classified according to different methods. The usual classification method is to classify by chemical composition. According to the chemical composition of the base rubber used for the sealant, the sealant can be divided into polysulfide, polyurethane, silicone, neoprene, butyl rubber, acrylic rubber and the like. At present, the larger amounts in the market are silicone, polyurethane, and polysulfide.

 

The construction sealant is classified into single-component and two-component packaging according to the packaging method. Single-component packaging is a mixture of all the raw materials that make up the sealant. It is sealed and packaged in a plastic bottle or flexible packaging aluminum film. Just type the product out of the packaging. Two-component packaging is composed of two components, A and B. In general, component A is the base rubber and component B is the curing agent. Fillers and other auxiliaries are added to component A and component B as required. When using, special machinery and equipment (two-component gluer) are used to mix components A and B uniformly according to the prescribed ratio. A, B The component is cured by chemical reaction, and neither the component A nor the component B can be used.

 

 

 

Sealant can be divided into chemical reaction type, solvent volatilization type, heat capacity cold setting type and other classifications according to curing characteristics. Silicone sealants are chemically reactive.