The formation of glass is the process of converting molten glass into a geometrically shaped article, a process known as primary forming or hot end forming of glass. The glass must be formed within a certain viscosity (temperature) range. In addition to mechanical movement, the glass fluid undergoes continuous heat exchange and heat transfer with the surrounding medium during forming. The glass liquid is first transformed from a viscous liquid state to a plastic state and then to a brittle solid state. Therefore, the glass forming process is an extremely complicated process.
The process of hot-formed glass being reworked into articles, referred to as glass reshaping (reprocessing) or cold end forming, can be divided into two categories: hot forming and cold forming. The latter includes physical forming (grinding and polishing, etc.) and chemical forming (high-silicon oxide microporous glass, etc.). The formation of glass generally refers to thermoforming.
Glass forming methods include: blowing method (hollow glass, etc.), pressing method (cigarette, water cup, etc.), calendering method (embossed glass, etc.), casting method (optical glass, etc.), drawing method (flat glass, glass) Tube, etc.), centrifugation (glass wool, etc.), sintering method (foam glass, process glass, etc.), spray method (glass beads, etc.), float method (flat glass, etc.), welding method (instrument glass, etc.).
The above forming method can be divided into two types according to the shape of the product, such as mold forming and moldless forming, and the mold forming is divided into a single side mold (blowing, centrifugal forming) and a double side mold (press forming).