Generally speaking: when the hardness of silica gel is lower than 10 degrees, the tear strength of silica gel is low, the elongation is large, and the silica gel products are easy to be deformed; When the hardness is higher than 40 degrees, the tear strength will become worse, and the silicone products will become brittle and easy to break or break. When the hardness of silica gel is 20-40, the tear strength and elongation are the best. In addition, the lower the viscosity (the better the fluidity) is, the more beneficial it is to the vacuum exhaust bubble, but at the same time, the tear strength will be worse, and the number of complex die will be reduced.

Liquid silicone belongs to food grade industrial products, commonly used in such as bottle, pacifier, tooth gum, the production of silicone products, so the minimum can do how many hardness, in silicone rubber hardness, generally less than 15 degrees of silica gel is called soft adhesive of low hardness, the silica gel is compared commonly demoulding easy and soft, and forming silica gel hardness can achieve zero at the bottom, condensation silicone minimum hardness at about 3 degrees.