In the silicone industry, liquid silica gel (LSR) generally refers to high temperature curing of two components plus silicone rubber. Typically, liquid silica gel products are catalyzed by platinum and molded by pouring or injection. Compared with high temperature vulcanized solid silicone rubber, liquid silica gel does not need mixing, low energy consumption, short molding cycle, high production efficiency, the production site is small, can realize a fully automated process.

The curing mechanism of liquid silica gel determines that there will be no by-products in the curing process, the shrinkage rate of the finished product is small, it can be deep vulcanized, and its physical and electrical properties are better. In addition, because liquid silica gel has thixotropy, low viscosity at high shear rate and good fluidity, it is especially suitable for the preparation of fine products and can realize the manufacturing of products with various complex shapes.

Many performance advantages and processing convenience of liquid silica gel have greatly broadened its application field, making it become a silica gel material variety with rapid development, higher grade, higher technical content and higher added value in recent years.

At present, liquid silica gel is mainly used in maternal and infant products, medical supplies, electrical and electronic, automotive and consumer goods and other fields, and with the change of market demand and technological progress and continuous development.

The medical and health sector, including infant care, is the largest application market for LSR. According to the statistics of national Strategic Alliance for Green Development of Silicon Industry (SAGSI), the consumption of LSR in China's medical and health market in 2019 was about 25,000 tons. Due to their good biocompatibility, LSR is mainly used in feeding bottles, pacifiers, medical catheters, medical appliance jackets and cosmetic prostheses.

Infant care, medical care, and food exposure are all sensitive application areas where stringent purity standards are set by the relevant legislative bodies to ensure product safety, such as the German Federal Institute for Risk Assessment (BfR) "XV. Silicone ", French decree of 25 November 1992, Swiss Regulation 817.023.21 on Food contact Materials and Products and European standard EN14350-2 for drinking equipment for infants and toddlers and EN1400 for pacifiers, etc. The above regulations use the weight loss of silicone products after special heat treatment (usually at 200°C for 4 hours) as a measure of VOC content.

During heat treatment, the weight loss of the dried sample shall not exceed 0.5% of its mass. The cured products of ordinary liquid silica gel must undergo secondary vulcanization in order to meet the above regulations. However, secondary vulcanization not only leads to a large amount of energy consumption, there is a risk of cross-contamination, and will affect the automated production process.