How is glass made?

The main component of glass is silicate double salt, which is an amorphous solid with irregular structure.

Glass is divided into tempered glass, porous glass (that is, foam glass with a pore size of about 40nm, which is used for seawater desalination and virus filtration), conductive glass (used as electrode and aircraft windshield), glass-ceramics and opaque glass (used for lighting devices and decorative items, etc.). ) and insulating glass (used as window glass).

The molecular arrangement of glass is irregular, and its molecules have statistical uniformity in space. In an ideal state, the physical and chemical properties of homogeneous glass (such as refractive index, hardness, elastic modulus, thermal expansion coefficient, thermal conductivity, electrical conductivity, etc. ) It's the same in all directions.

The production process mainly includes:

① Pretreatment of raw materials. Bulk raw materials (quartz sand, soda ash, limestone, feldspar, etc. ) crushing, drying wet raw materials, removing iron-containing raw materials, and ensuring the quality of glass.

(2) Batch preparation.

(3) melting. The glass batch is heated at high temperature (1550~ 1600℃) in a tank kiln or crucible kiln to form uniform, bubble-free liquid glass that meets the molding requirements.

④ molding. Liquid glass is processed into products with required shapes, such as flat plates and various utensils.

⑤ Heat treatment. Through annealing, quenching and other processes, the internal stress, phase separation or crystallization of glass are eliminated or produced, and the structural state of glass is changed.