Oil spray, also known as surface treatment and baking varnish.
Painting (Painting) is a kind of name in Taiwan, the surface coating processing of industrial products.
Oil injection processing includes plastic injection, silk screen printing, and pad printing. According to customer requirements, products such as high temperature resistance, friction resistance, UV resistance, alcohol resistance, and gasoline resistance can be produced.
Processing steps:
1. Annealing
Internal stress is easy to form when plastic is molded, and the stress concentration area is easy to crack after coating. Annealing treatment or whole surface treatment can be used to eliminate stress. The annealing treatment is to heat the ABS plastic molded parts to below the heat distortion temperature, that is, 60°C, and keep the temperature for 2 hours.
Since the use of this process requires a lot of equipment investment, the whole surface treatment technology can be used, that is, the solution that can eliminate the internal stress of the plastic part is configured to treat the surface of the plastic part for 15-20min at room temperature;
2. Degreasing
The surface of plastic parts is often stained with oil, hand sweat and release agent, which will make the coating adhesion worse, and the coating will crack, blisters and fall off.
Degreasing treatment should be carried out before painting. Plastic parts are usually cleaned with gasoline or alcohol, and then chemical degreasing. After chemical degreasing, the residual lye on the surface of the workpiece should be thoroughly cleaned, and finally cleaned with pure water, dried or dried;
3. Static electricity and dust removal
Plastic products are insulators, and the surface resistance is generally above 10 to the 12th power Ω. It is a good insulator, but it is easy to generate static electricity.
After being charged, it is easy to absorb fine dust in the air and adhere to the surface. It is very difficult to remove the dust adsorbed by static electricity by the general blowing method, and the effect of using high-pressure ionized air flow to remove static electricity and dust is better;
4. Spraying
The thickness of the plastic coating is 15-20μm, and it usually takes 2 to 3 sprays to complete. After one spray, let it dry for 15 minutes, and then perform a second spray.
The surface that needs to be bright must also be sprayed with clear paint. The coated parts have basically no effect on the flame retardant performance;
5. Drying
Generally, the paint is baked at 150-180℃ for about 20-30 minutes.
Plastic paints are baked at 60-80℃ for about 20-30 minutes. Some special paints can dry themselves in the greenhouse.