Fumed silica gel is more suitable for toys for the following reasons:
Safety and environmental protection
Fumed silica gel: made of silicon dioxide generated by the combustion of silicon tetrachloride and air, with a fineness of more than 1000 mesh, a high environmental protection index, and meets environmental protection requirements such as ROHS. It has passed the US FDA certification and the EU LFGB food standard test. This means that in toy manufacturing, even if fumed silica gel is in long-term contact with children's skin, it will not produce harmful substances, ensuring the safety of toys.
Precipitated silica gel: made of sodium silicate and sulfuric acid precipitated silica dioxide, with a fineness of 300-400 mesh. The price of raw materials is relatively low, but the environmental protection and safety are slightly inferior to fumed silica gel. Although precipitated silica gel also has certain environmental protection, fumed silica gel has more advantages under high safety standards.
Physical properties
Fumed silica gel: has excellent tear resistance, elongation and resilience. Its tensile strength can reach 7.8-10.0MPa, the tear strength is up to 49kN/m, and the elongation is in the range of 500-1000%. These characteristics enable toys made of gas phase silica gel to withstand large stretching and twisting without breaking, and are suitable for making toys that require high elasticity and tear resistance, such as silicone dolls, squeeze toys, etc.
Precipitated silica gel: Although it also has a certain tensile strength and elongation, its tear resistance and resilience are poorer than those of gas phase silica gel. Precipitated silica gel is more suitable for making some toys that do not require high stretching and tear resistance, such as remote control buttons, mobile phone buttons, etc.
Transparency and appearance
Gas phase silica gel: High transparency, adjustable from translucent to fully transparent. This allows gas phase silica gel to present more vivid and realistic colors when making toys, enhancing the ornamental and attractiveness of toys.
Precipitated silica gel: The appearance is opaque or translucent, and the transparency is low. This limits the application of precipitated silica gel in toy manufacturing to a certain extent, especially for toys that require high transparency.
Heat resistance and chemical corrosion resistance
Gas phase silica gel: It has a wide temperature resistance range, from -60℃ to 250℃, and also has anti-ozone aging performance. This allows toys made of gas phase silica gel to maintain stable performance in various temperature environments and are not easy to deform or age. In addition, fumed silica gel also has good chemical resistance and can resist corrosion from a variety of chemicals, ensuring the durability of toys.
Precipitated silica gel: Although it also has certain temperature resistance and chemical resistance, its performance is slightly inferior to that of fumed silica gel. In high temperature or harsh environment, toys made of precipitated silica gel may be more prone to deformation or aging.