Functions of optical finishing include:
1. Improve the shape and flatness of the plate.
2. Reduce or eliminate the yield platform of the steel plate, so as to temporarily reduce or eliminate the phenomenon of slippage line when the coated steel plate is used for forming and processing.The yield platform is temporarily eliminated by large amount of photofinishing, which can be maintained for several days.
3. Keep the plating crystal flat to reduce the fluctuation of the plating surface.Here say "crystal flower", and do not say "zinc flower", because, because, the crystalline pattern of hot dip galvanization layer just calls zinc flower, if other kinds of hot dip coating crystallization pattern also call zinc flower, it is not appropriate, but the crystalline pattern of all kinds of hot dip coating can be called crystal flower.
4. Given the surface roughness.This requires that the surface of the smooth work roll be brushed in advance by means of sand blasting, electric spark beating or laser tapping.The working roller with different surface roughness will give different surface roughness to the plating plate.However, the surface roughness of the plating plate is not equal to the surface roughness of the working roller, because after the leveling processing, the elastic deformation of the plate surface disappears, and only the plastic deformation remains.The "copy coefficient" is generally 0.5~ 0.6, that is, the roughness formed on the surface of the plate is the smooth working roll, and the roughness of the roll surface is 50 ~60%.
Photofinishing elongation (also called flatness) in hot-dip galvanizing production line: maximum 2%.