The silicone strap of the watch material.

Silica gel is a large family, divided into inorganic silica gel and organic silica gel. Inorganic silica gel is a kind of high activity adsorption material, usually with sodium silicate and sulfuric acid reaction, and through aging, acid bubble and other series of post-processing process. Its main component is silicon dioxide, the structure is like a spongy body. The interconnected pores constitute a capillary adsorption system with huge surface area, which can adsorb and coagulate the water vapor of 40 percent of its own weight, so it is used in desiccator. Inorganic silica gel is not used for making strap, but is often used in watch care - as long as put silica gel particles and water watch in an airtight container, in a few hours later, so the water inside the watch will all but disappear. Our daily use is more organic silicone, which is divided into silicone rubber, silicone and silicone oil, which is a kind of special rubber in synthetic rubber. The material used in the watch band is a small branch of the organic silicone family, known as the room temperature vulcanized silicone rubber (RTV) in silicone rubber. Silicone rubber is made from silicon powder, methanol and hydrochloric acid, which can be obtained through a series of complex chemical processes. The silicone rubber is also known as "liquid silica gel" because it has a low molecular weight and is liquid at room temperature. In liquid silicone with crosslinking agent and platinum catalyst, it into a model, after a period of time after vulcanization reaction can curing (room temperature response, so called room temperature vulcanized silicone rubber, also can be a little heat to improve response speed). And form the final product. Adding different additives can make silica gel material with different specific gravity, hardness, strength, color and texture.