Frit is a multi-element solid mixture that does not have a fixed melting point during the heating process. Instead, it gradually begins to melt, melts, and melts within a certain quantitative range, forming a multi-component low-temperature mixture. Melt. Generally, the melting temperature is the temperature at which the material to be melted is made into a small cylinder of a certain standard and heated and softened until it forms a hemispherical shape with the bottom plane; the melting temperature range refers to the temperature range experienced in the process from initial melting to complete melting. Reasonable melting temperature and melting cycle play a very important role in the quality of frit. The melting temperature is too low, the melting cycle is prolonged, the melt viscosity is high, the exhaust is poor, and the inclusion is serious; the melting temperature is too high, the melting cycle is too long, not only increases the energy consumption of the equipment, reduces the production capacity, but also intensifies the melting process. The volatilization of flux raw materials in the block affects the quality of the frit. Generally, the melting temperature of ordinary frits should be controlled at , while the melting temperature of high-end frits should be controlled at . , For frits with high alkaline earth metal content, the melting and clarification time can be appropriately extended to make the melt fully exhausted and the frit crystal clear.

The melting process of the flux is carried out at high temperature. The reaction is very complicated and it is difficult to obtain the fullest understanding at present. It can be roughly divided into the following stages: silicate and molten metal. Formation, melting of residual quartz and formation of glass, clarification and homogenization of glass melt. At first, it was mainly a reaction between solid phases, and then a small amount of liquid phase began to appear when SiO2, etc. interacted with flux or other components to form a low-density melt. The reaction quickly turned to solid-liquid, and a lot of liquid phases were produced at the same time. As an intermediate product, the liquid phase continues to expand and becomes an opaque sinter composed of silicate and free SiO2.