The stripes produced by ordinary glass are mainly due to uneven mixing of materials; Corrosion of refractory materials (mainly introduced by Al); Generated by agitation during the manufacturing of glass products.
So optical glass needs to start from these aspects, as well as the high requirements for the particle size and weighing of raw materials. Melting furnaces use ceramics or platinum as refractory materials. Generally, only casting method, rolling method, breaking cylinder method, and liquid method are used for molding, which reduces the agitation of glass during molding.
In addition, the structure of the melting furnace is different from that of a daily glass melting furnace. It is divided into a melting pool (feeding), a regulating pool (regulating the melting atmosphere), a refining pool (clarification), and a homogenization pool (stirring). The daily output of a large furnace is generally only 5 tons.