Glass bottles are made by pre-processing of raw materials, preparation of ingredients, melting, molding, heat treatment and other processes. Among them, heat treatment includes overannealing, quenching and other processes. the purpose of heat treatment is to eliminate or produce stress, phase separation or crystallization in the glass, and to change the structural state of the glass.
The glass mixture is heated at a high temperature of 1550 to 1600 degrees in a pool kiln or pool furnace to form a uniform, bubble-free liquid glass that meets the forming requirements. Put the liquid glass into the mold to make the required shape of glass products, such as flat plates, various utensils and other heat treatment.
Raw materials for glass bottles
The glass bottle is made of quartz sand as the main raw material, and other auxiliary materials are melted into liquid at high temperature, and then the essential oil bottle is injected into the mold, cooled, cut and tempered to form the glass bottle. Glazed bottles generally have rigid marks, which are also made of mold shapes. According to the production method, the forming of glass bottle can be divided into three types: manual blowing, mechanical blowing and extrusion molding.
Heat treatment technology of glass bottle
The glass bottle has undergone drastic temperature and shape changes in the molding process, which leaves thermal stress in the glass. This thermal stress will reduce the strength and thermal stability of glass products. If it is cooled directly, it is likely to break itself during the cooling process or later during storage, transportation and use.
In order to eliminate the phenomenon of cold explosion, glass products must be annealed after forming. Annealing is heat preservation or slow cooling in a certain temperature range for a period of time to eliminate or reduce the thermal stress in the glass to the allowable value.
In addition, some glass products can be stiffened in order to increase their strength. Including physical hardening (quenching) for thicker glasses, tabletop glass, car windshield, etc., and chemical hardening (ion exchange) for watch cover glass, aviation glass, etc. The principle of stiffening is to generate compressive stress on the surface layer of the glass to increase its strength.
