Process flow of spray coating equipment

Pre-treatment process: degreasing and decontamination of aluminum material → water washing → alkaline washing (degreasing) → water washing → pickling → water washing → chromization → water washing → pure water washing

Spray coating equipment process: spray primer → top coat → finish varnish → baking (180-250℃) → quality inspection

The multi-layer spraying process consists of three sprays (referred to as three sprays), spray primer, top paint and finishing paint, and second spray (primer, top paint).

1. The purpose of pre-treatment: before spraying on aluminum alloy profiles and plates, the surface of the workpiece must undergo degreasing, decontamination and chemical treatment to produce a chromium film, increase the bonding force of the coating and the metal surface and the oxidation resistance, which is beneficial to extend the paint The service life of the membrane.

2. Primer coating: as a primer coating for a closed substrate, its function is to improve the coating's anti-permeability ability and enhance the protection of the substrate.

Stabilize the metal surface layer, strengthen the adhesion between the top paint and the metal surface, and ensure the color uniformity of the top paint coating. The thickness of the paint layer is generally 5-10 microns.

3. Topcoat: The topcoat is the key layer of the spray coating. It provides the decorative color required by the aluminum material, so that the appearance of the aluminum material meets the design requirements, and protects the metal surface from the external environment, acid rain, and pollution. , To prevent ultraviolet rays from penetrating. It greatly enhances the anti-aging ability. The top coat is sprayed with a medium-thick layer of paint, and the thickness of the paint layer is generally 23-30 microns.

4. Finishing paint coating: Finishing paint coating is also called varnish coating. Its main purpose is to more effectively enhance the anti-corrosion ability of the paint layer, protect the top paint coating, increase the metallic luster of the top paint color, and make the appearance more vivid. The brilliance is dazzling, and the thickness of the coating is generally 5-10 microns.

The total thickness of the three spray coatings is generally 40-60 microns, and can be thickened for special needs.

5. Curing treatment: The three-spray coating generally requires secondary curing. The aluminum material is processed in the curing furnace. The curing temperature is generally between 180℃-250℃, and the curing time is 15-25 minutes. Different fluorocarbon coating manufacturers will follow their own specifications. Coating, provide the best temperature and time. Some chlorocarbon spraying plants (curium oil plants) also changed the two curing of three sprays to one curing based on their own experience.

6. Quality inspection: The quality inspection shall be in accordance with the AAMA-605.02.90 standard. Strict quality inspection can guarantee high-quality spray products.