Grinding is to grind off the rough and uneven glass of the liquor bottle product or the remaining part of the glass when it is formed, so that the product has a flat surface or the required shape and size. Generally, use coarse abrasives with high grinding efficiency to grind, then use fine abrasives step by step until the glass surface is finer, and then polish with polishing materials to make the glass surface smooth, transparent and shiny.
The hardness of the abrasive must be greater than that of the glass. Optical glass and daily products generally have a large machining allowance, and use corundum or natural emery as abrasives; flat glass has a small machining allowance, but a large area and a large amount of use, generally using cheap quartz sand. Commonly used glass bottle polishing materials are red powder (iron oxide), cerium oxide, chromium oxide, zirconium oxide, etc. Fire polishing is to use a burner with less radiant heat, so that the surface of the product is melted without deformation and smoothed by surface tension, so as to eliminate micro-cracks, folds and ripples on the surface of the product.
Chemical polishing is to use hydrofluoric acid to destroy the original silicon oxide cloth on the glass surface to generate a new layer of silicon oxide cloth, so that the glass has a high degree of finish and light transmittance. Chemical erosion can be used for polishing alone, or chemical erosion can be combined with mechanical grinding. The latter is also called chemical grinding, which is mostly used for flat glass.