4、 Surface preparation options and the importance of surface pretreatment
From a dazzling mirror-like appearance to a totally non-reflective texture, specially prepared surface finishes add both functionality and attractiveness to many products. A matte finish is normally used on the interior of cameras, microscopes and other optical products. The front panels of many pieces of electronic equipment have a brushed or satin finish, while a number of consumer products have enhanced appeal due to their highly polished appearance. Medical and dental tools for surgery are another application where a smooth polished surface is required. More than one texture can often be utilized on a single component.
Here are some common surface preparation options：
POLISHING-Both manual and automated polishing techniques are often utilized before anodizing to smooth irregularities and increase surface reflectivity. Polishing provides a highly decorative and mechanically smooth surface. A highly polished and anodized finish adds eye appeal and value to any component.
A grained, brushed, or satin surface yields a high-tech satin look. (pictures as below)
Lapping and blasting-These techniques create a non-reflective finish, within a range of controlled textures.
Why is the uniform pretreatment so critical for color anodizing performance？Color anodizing uses electrolysis to create an oxide layer on the metal surface. It is similar to making a mirror with the glass sheet, the more flat, the better the glass is, the more real mirroring will be.
For example, a good surface pretreatment will be more apparent after color anodizing, which will result in a more uniform and beautiful color. Otherwise, any slight surface preparation defects will be magnified after color anodizing. This is totally different from common painting process as color anodizing will not cover defects of surface pretreatments.
Comparison：
Uneven surface pretreatment： Good surface pretreatment：
Uneven after anodizing ： Color uniform：
