China White Birch UV plywood Part 11 :Seven points for attention in the application of UV coatings
1. Unlike metal, UV coating primer and topcoat plastic parts must be cured at low temperature (generally 60-80 C). Commonly used topcoat materials are polyurethane (PU) and acrylic resin UV coatings. When the surface of UV coating needs metallic luster, a layer of silver primer should be sprayed under the transparent finish.
In order to increase the wear resistance of UV coatings, a layer of UV-cured UV coatings is usually sprayed on the outer surface. The brightness of UV coatings is required to be satisfied by different proportion of high-light UV and matte uv.
2. The spraying process of plastic parts can be divided into manual spraying and automatic spraying. Manual spraying: the thickness and quality of UV coating are not easy to control. Mainly used for initial batching test spraying and inner surface conductive UV coating spraying. Automatic spraying: multi-gun (6 guns and 8 guns, etc.) spraying. Adjust different spraying angles to achieve uniform surface thickness, but also spraying with a manipulator. Note: Before spraying, the code number, color and surface roughness of the substrate must be determined.
3. In order to make the color of the UV coating stable in gloss and wear resistance, the thickness of the UV coating must be controlled. UV coating thickness can be measured directly by UV coating thickness gauge. Silver primer (for metallic luster) is thinner, generally 3-5?M: UV coating thickness of topcoat is generally 8-10?M: UV coating thickness is generally 8-15?M.
4. The color and brightness can be detected by chromatometer and brightness meter. This method can be quantified by data, but its accuracy is poor. Usually the color plate is used to detect by comparison method.
5. After the color code and color plate are proposed by the color design department, the UV coating manufacturer (or cooperates with the spraying manufacturer) prepares the UV coating and sprays it on the automatic spraying line. The design department carries on the comprehensive examination to the test spray sample, after passing, carries on the signature, simultaneously determines the UV coating code. If it fails to meet the design requirements, this process can be determined after repeated repeated.
6. Wear-resistance and peeling-resistance tests are carried out on the “RCA Wear-resistance Tester”, and peeling-resistance strength tests are determined by the percentage of UV coating peeling off with a baiger knife and 3M tape.
7. There are many manufacturers of UV coatings at home and abroad at present. The UV coatings produced by them have their own characteristics and can be selected according to needs.