Mirror is an object with smooth surface, which originally employed a polished bronze for reflecting light by ancients. There are two kinds of mirror: flat mirror and curved mirror. Flat mirror is often used to adjust appearance. Curved mirror including concave mirror and convex mirror are mainly used for dressing furniture, building decoration, optical instrument parts, solar cooker, automotive light, searchlight mirrors, reflecting telescopes, vehicle rear mirror etc.
In scientific filed, mirrors are also often used as telescopes, lasers, industrial instruments, regular reflective surface polishing metal devices and glass or metal products, coated with metal reflectors along with plastic or wooden borders.
There are generally two ways to produce mirrors’ reflecting surface: chemical silvering and vacuum evaporating. Chemical silvering is mostly used and could be manufactured via dissolving silver nitrate in water and diluting with ammonia and sodium hydroxide to form silver hydroxide, then to convert sugar or formaldehyde, seignette salt solution into reducing solution. Glass needs to be trimmed, trimmed (polished if necessary) and washed. After that, we will use stannous chloride to mix, clean and then immerse the surface with silver plating solution and reducing solution. At last, we need to wash the mirror again and coat it with cooper or protection paint.
The vacuum evaporating method is to wash the glass and put it in the 0.1~10pa vacuum evaporation device. The spiral tungsten wire is electrified and the high temperature of the wire causes the aluminum alloy in the spiral to vaporize into a gaseous state and deposit on the surface of the glass to form a mirror. Electron gun can also be used to take place of tungsten wire heating. Vacuum evaporating process enables to smooth metal surface into a mirror.
Please kindly refer below detailed manufacturing procedures.
A. Washing glass
Cutting the glass as per specifications, you need to rinse both sides with water first, then apply the iron red powder with water to coat the side. After drying, please wipe the iron red powder and wash it clean. Then scrub the surface of the glass with a trace of stannous chloride solution. After that, you can clean the remaining stannous chloride with water. Finally flush the glass with clean water (preferably distilled water).
B. Coating sliver
First, we need to place the washed glass on a horizontal frame or strip, then to mix silver in a portion of the silver solution and a portion in the reducing solution. The amount is about two minutes per square metre. When it gradually reacts with the glass to become silver mirror, we will rinse the excessive liquid with water and pour 10/1000 gelatin for drying. After drying , we will coat it with a layer of iron red primer or other anti-rust paints to become a mirror.
C. Liquid formulation
Silver solution: distilled water (cold boiled water is fine) 2500 milliliters, silver nitrate 25 grams, ammonia 18.5 milliliters (after chemical clarifcation's reaction).
Reduction solution: distilled water (cold boiled is fine) 2500 milliliters, potassium sodium tartrate 25 grams, then add silver nitrate 0.5 percent into the solution after clarification. The liquid medicine will be reserved for filtration.
Gelatin solution: water 1000 milliliters, gelatin 10 grams, steamed without water.
Iron red primer needs to be added proper amount of banana aqueous solution.