The appearance of the coating film can be divided into two categories: visual inspection method and optical measurement method. Visual inspection is to directly observe whether there are defects on the surface of the coating film, such as particles, bubbles, pinholes, pitting, spots, cracks, scratches, etc. According to GB4054-83, the coating appearance grades are divided into four categories (Table 3_8_1).
The optical measurement method is to use various optical instruments to measure the brightness, flatness, color and color uniformity of the coating film.
Table 3_8_1 coating appearance grade
grade | code name | feature |
level one | I | The surface of the coating film is plump, bright (except dull and semi-gloss coatings), smooth, consistent in color, beautiful, and finely modified in geometric shape. There are basically no mechanical impurities, no traces of trimming and other defects, and the art coating should also have clear texture, uniform distribution, and prominent features, with a strong artistic effect Product coating for advanced finishing requirements |
Secondary | II | The coating film is basically flat and smooth. The color is basically the same, the geometric shape is well modified, there are few mechanical impurities, there are no obvious repair marks and other defects, and there are no defects in protective performance. The artistic coating should also have clear texture, relatively uniform distribution, and artistic characteristics. Used for product coating with higher decorative requirements |
Level three | III | The coating film is complete and there is no significant difference in color. A small amount of fine mechanical impurities, trimming marks and other defects are allowed on the surface. There are no defects that affect the protective performance, and the artistic coating should also have artistic characteristics Used for coating of products with general decorative requirements |
Level 4 | IV | The coating film is complete. Defects that do not affect the protective performance are allowed Used for product coating without decorative requirements |