Reinforcement of rubber
Reinforcing silica for rubber is widely used as a reinforcing agent in the rubber industry, accounting for 70% of the total usage. Especially when manufacturing white, colored and light-colored rubber products, it is more suitable due to the fact that the white color of silica is easy to color. For instance, the tensile strength of unreinforced silicone rubber does not exceed 0.4MPa. After being reinforced with fumed silica, the strength can be increased by 40 times.
Delustering agent
Silica has a huge surface area and a refractive index of 1.45 to 1.50. The paint film containing hydrated silica matting agent will undergo diffuse reflection when light enters, thus forming a matte and matte appearance with a glossy finish. The particles of fumed silica are looser, and the number of particles per unit mass is greater than that of precipitated silica. Therefore, under the same addition amount, fumed silica has a higher matting effect and better transparency.
Be used as abrasivus
In addition to its large surface area, hydrated silica also has a very strong adsorption capacity. Therefore, hydrated silica is one of the main types of toothpaste abrasives at present. Due to the superior transparency and abrasives of fumed silica, many crystal clear toothpaste ingredients contain fumed silica.
Used for gluing and strengthening of paper
Hydrated silica has excellent wear resistance and strength. As mentioned above, it is very "white". Therefore, when hydrated silica is used in paper, it can enhance the whiteness and opacity of the paper, making it more wear-resistant, oil-resistant and having a better luster. For instance, adding 1-2% fumed silica to newsprint can reduce its weight by 10%, enhance its strength and prevent ink penetration.
Anti-settlement effect
When used in adhesives and sealants, hydrated silica can play a role in controlling rheology, preventing sedimentation, preventing sagging and reinforcing. In addition, fumed silica, with its superior performance, is widely used as a rheology modifier, anti-settling agent and dispersant in the fields of paints, inks and coatings.