1. Mechanical polishing
The main method of mechanical polishing is to use abrasives and grinding discs to mechanically grind the glass surface to grind away the microscopic protruding parts of the glass surface. Grinding and polishing discs are generally made of wool felt, and the most commonly used polishing material is oxide decoration. Regarding the glass grinding mechanism, it is generally believed that the grinding action starts, and then the fresh surface of the glass is with water to produce a silica gel film. The silica gel film is ground again, and after repeated repetitions, the glass surface is gradually polished to a smooth surface.
There are many factors that affect the grinding and skimming. The speed of the grinding wheel, the hardness of the abrasive, the size of the abrasive particles and the grinding pressure will all affect the grinding effect.
In the architectural glass processing industry, there is basically no large-scale mechanical polishing equipment. Various small polishing machines are mainly used to remove defects such as scratches and spots on the glass surface during processing.
2. Chemical polishing
Chemical polishing mainly uses the corrosive effect of hydrofluoric acid to polish the glass surface. Hydrofluoric acid destroys the silicon-oxygen structure of the glass surface. The glass surface is peeled off to obtain a new smooth surface.
The acid polishing of glass is a chemical reaction process between hydrofluoric acid and the glass surface. Generally, the composition of silicate glass includes Si02Nai0, K,0, CaO, etc. After reacting with HF, Si Fan, NaF, KF, CaF2 are formed, and various fluorosilicates are formed, except for calcium-containing fluorosilicates. Except for water, other fluorosilicates are insoluble in water. Therefore, sulfuric acid is often added to the polishing solution to dissolve various fluorosilicates and prevent the chemical reaction on the glass surface from being hindered.
The chemical composition of the glass, the ratio and temperature of the acid solution, and the reaction time of the acid solution with the glass are all factors that affect the polishing effect.
Due to limitations in use and impact on the environment, chemical polishing is basically not used on architectural glass, but the use of hydrofluoric acid etching to make process glass is still widely used.
3. Mechanical grinding of glass
Under the pressure of the grinding disc and the relative movement of the glass surface, the abrasive is used to grind away the unevenness of the glass, but the glass surface becomes rough. Coarse-grained abrasives have fast grinding speed and rough surface. Therefore, multi-level abrasives are commonly used. Polishing discs are used to add polishing liquid to the glass surface to obtain a smooth surface of the glass. This is polishing.
Flat frosted glass is opaque frosted glass, which is used for lighting but not transparent. Its frosted surface can be obtained by rough grinding. Glass grinding can also be performed with a non-free abrasive grinding wheel. The grinding wheel can be made of corundum, silicon carbide, diamond and other abrasives. , Just add water when grinding glass. The frosted joints and pistons of instrument glass are ground on a grinder or lathe with various grinding wheels.
Grinding disc material: The grinding disc material has high hardness, which can improve the grinding efficiency. The grinding efficiency of cast iron materials is 1, non-ferrous metals is 0.6, and plastics is only 0.2. However, the grinding disc with high hardness makes the depth of the dent on the grinding surface deeper, and the plastic disc with lower surface hardness can reduce the depth of the glass depression by 30% compared with the cast iron disc. Therefore, the polishing time can be greatly shortened if the plastic disc is used for the last-level abrasive.
Polishing disc material: Generally, the polishing disc is made of felt, but also woolen, maran grass root, etc. The polishing efficiency of coarse felt or semi-wool felt is high, and the polishing efficiency of fine felt or woolen cloth is low. The engraving, polishing lines, and patterns on the glass surface of the decorative utensils are also done by grinding, but it is done with small-sized iron wheels, copper wheels and abrasives and water, or grinding wheels with water. The surface of glass products is deep, usually rough grinding and fine grinding and then polishing.
This is some relevant knowledge about glass deep processing. I hope everyone can learn some common sense and avoid some misunderstandings.
