Surface chemical plastic bucket has two coating

Surface chemical plastic bucket has two coating

 

   Chemical treatment of surface plastic bucket two coatings and coating coating coating treatment process. Crystallinity of the plastic is larger, less polar or non-polar, surface chemical plastic bucket can be low, it will affect the adhesion of the coating to the coating. Since plastic is non-conductive insulator, it is not by an electroplating process specification chemical plastic barrels surface coating directly coated, so before chemical plastic bucket surface treatment, pre-treatment should be necessary, in order to increase the bonding coating coated force and to provide good adhesion for coating conductive primer coating treatment.

1. Pretreatment coating coated plastic chemical barrels

Pre-treatment including plastic surface degreasing treatment, namely the removal of oil and release agent plastic surface, as well as plastic surface activation treatment, aims to improve the adhesion of the coating covered.

(1) chemical plastic barrels of oil. And degreasing metal surface similar to plastic alkaline degreasing solution cleaning or degreasing available organic solvents containing surfactants. An organic solvent for cleaning paraffin oil, beeswax, fats and other organic soils from the plastic surface, of the organic solvent should not dissolve the plastic products, non-swelling, non-cracking, low boiling point itself, volatile, and non-toxic non-combustible.

Aqueous alkaline solution suitable for alkaline degreasing plastic products. Because this solution contains caustic soda, alkaline salts and a variety of surface active substances. The most commonly used surface-active substances for the OP series, namely alkyl phenol ethoxylates, it does not form a foam, not remaining on the surface of the plastic products.

(2) chemical activation of the surface of the plastic bucket. Activation is to increase the surface energy of plastic products, is a plastic surface to generate a number of polar groups or roughened to make coating easier wetting and adsorbed on the surface of the workpiece. There are many ways to activate the surface of plastic products, such as chemical oxidation, flame oxidation, solvent vapor etching method and corona discharge oxidation method. One of the most widely used chemical polycrystalline oxidation treatment method, this method is commonly used chromate treatment solution, the typical formula of potassium dichromate 4.5%, 8.0% water, concentrated sulfuric acid (96%) 87. 5%.

But also on the surface of the plastic chemical barrels were chemical coating covering direct some plastic barrels, plastic products such as polystyrene and ABS plastic products, has no chemical oxidation process. In order to obtain high quality coating coated, but also chemical oxidation treatment, such as ABS plastic, after degreasing, may be relatively dilute solution of chromic acid etching treatment, typical chromic acid treatment formulation was 420g / L, sulfuric acid (specific gravity 1.83) 200ml / L. A typical treatment process is 65 ℃ 70 ℃ / 5min10min, wash water, and dried.

Advantages treated with chromic acid etching solution is that no matter how complex the shape of plastic products, can be uniform treatment, but some danger on the operation, but also the presence of the pollution problem.