GEIT Electric Equipment Factory

Pre-treatment- Color coating line

The pretreatment is a process which to remove grease and iron powder on the steel sheets surface, and provide a clean surface for the subsequent process in color coating line, that is contribute to improve the adhesive force and durability between the materials and the paint. It includes two process: cleaning process and chemical treat process.

The cleaning process in color coating line is mainly including continuous alkali spraying. scrubbing and mulit-stage circulating water spraying ,rinsing as well as hot air heating. Through alkali spraying, it can wipe off 80%-90% greasy dirty and prevent the greasy to the entry looper to achieve degreasing purpose, after that,  The steel strip passes through 2-3 spray tanks which provide a path length of 8.5 m and then an immersion length of 5m equal to a total cleaning time of 4 seconds at 200 m/min. then use scrubbing method to brush the upper and lower surface of strip to degrease,  afterwords, the steel strip will be rinsed thoroughly by means of multi-stage water and fresh water spraying to wash off the alkali liquor on strip surface, and at last to dry by means of hot air heating.

The chemical treat process is typically a no-rinse chrome chemical type, is applied to each side of the strip by roller coating. It can strength the adhesive and corrosion resistant and protect the base sheets are not affected from water and other corrosive media. afterwords, the steel strip will enter the chemical drying oven for drying to prepared for next primer coating process.

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