Among all soft colloids, silica gel is one of the materials with the best properties. It is comprehensive and high-quality in all aspects, so many industries choose to use it as the main body or spare parts. Food grade and ordinary grade are also divided into gas phase grade and precipitation grade. The difference between the two is that the compounds of the materials are different, and the main body is basically the same.

For example, precipitated silica gel is mainly precipitated silica, which uses fuel gas to mix water glass made of quartz sand and soda ash at high temperature into a dilute solution with high concentration, and then adds certain compounds, which are washed, filtered and crushed to obtain precipitated silica. A precipitated silicone rubber raw material obtained by adding silicone oil, silica and other substances.

The gas-phase silica gel is a gas-phase silica gel material obtained by adding silicone oil, white carbon black, siloxane and other substances into the silica gel obtained from the combustion of silicon tetrachloride. It is also called food-grade silica gel, and its density is high, and the detail degree of silicon molecules can reach more than 1000 meshes. Therefore, the tensile resilience and tear resistance of products are better than those of ordinary silica gel materials, but the price is also more expensive.

However, it is difficult for you and me to tell with naked eyes whether a silicone product belongs to an ordinary silicone material or a food-grade silicone material, so the only way to do so is to use skills. For example, when the tensile rebound occurs, the white mist of ordinary silicone will appear on the surface of the stretching point, which is obvious, while the white mist will not appear when the gas phase adhesive is stretched.

Secondly, when ordinary silica gel is burned, white smoke will appear, but after the product is burned, the powder particles belong to one by one, which is easy to break, and this phenomenon will also occur when the gas-phase gel is burned. However, the burning powder of food-grade silica gel is thinner and not easy to break, and the burning time is longer than that of ordinary precipitated gel.

Therefore, you can tell whether they are food-grade or ordinary-grade materials by basically pulling them by hand, but of course, it's not ordinary glue that can't meet the requirements of safety and environmental protection. At present, food-grade silicone materials are mainly used in places that touch the skin in life, such as silicone kitchen utensils, silicone daily necessities,silicone tableware, silicone pacifiers, etc., while ordinary glue is usually used in electronic equipment, silicone seals, silicone gaskets, etc., so there are some differences.