What is the importance of pretreatment of chromium plating?
Pre-treatment: All processes before plating are called
pre-treatment, whose purpose is to trim the surface of the
workpiece, remove the grease, rust, oxide film, etc., on the
surface of the workpiece.
Provide the required plating surface for subsequent deposition of
the coating.
Pre-treatment mainly affects the appearance and binding force.
According to statistics, 60% of defective electroplating products
are caused by poor pre-treatment.
Therefore, pretreatment plays an important role in electroplating
process. In countries with developed electroplating technology,
great importance is attached to the pre-treatment process.
The pretreatment process accounts for half or more of the whole
electroplating process, so the coating with good surface condition
can be obtained and the defect rate can be greatly reduced.
Sand blasting: remove rust, welding slag, carbon deposit, old paint
layer, and other dry oil stains on the surface of parts;
Remove sand and oxide skin from the surface of castings, forgings
or heat-treated parts;
Remove burrs and directional wear marks on the surface of parts;
Reduce the roughness of parts to improve the adhesion of paints and
other coatings; The part is diffuse reflection extinction state
Polishing: To remove burrs, rust, scratches, welds, bumps, sand
holes, oxide skin and other macro defects of parts to improve the
flatness and plating quality of parts.
Polishing: The purpose of polishing is to further reduce the
roughness of the surface of the parts and obtain a bright
appearance. There are mechanical polishing, chemical polishing,
electrochemical polishing and so on.
Degreasing: remove grease from workpiece surface. There are organic
solvent oil removal, chemical oil removal, electrochemical oil
removal, wipe oil removal, roller oil removal and other means.
Pickling: remove surface rust and oxide film.