1. Annealing: Internal stress is easily formed during plastic molding, and the stress concentration is easy to crack after coating. Annealing or full-face treatment can be used to eliminate stress. The annealing treatment is to heat the ABS plastic molded part below the heat distortion temperature, that is, 60 ° C, and keep it for 2 h. Since the use of such a process requires a large investment in equipment, a full-face treatment technique can be employed, that is, a solution capable of eliminating the internal stress of the plastic part can be subjected to treatment of the surface of the plastic part at room temperature for 15 to 20 minutes.
2. Degreasing: The surface of plastic parts is often stained with oil, hand sweat and mold release agent, which will make the adhesion of the paint worse, and the coating will crack, blister and fall off. Degreaser treatment should be carried out before painting. The plastic parts are usually cleaned with gasoline or alcohol, and then chemically degreased, chemically degreased, the residual lye on the surface of the workpiece should be thoroughly cleaned, and finally cleaned with pure water, dried or dried.
3. Electricity and dust elimination: plastic products are insulators, the surface resistance is generally around 1013Ω, easy to generate static electricity. After charging, it is easy to adsorb fine dust in the air and adhere to the surface. It is very difficult to remove dust due to electrostatic adsorption by a general blowing method, and the effect of removing and discharging dust by using a high-pressure ionized air stream is good.
4. Spraying: The thickness of the plastic coating is 15~20μm, usually 2~3 times to complete. After spraying, dry for 15 minutes and then spray for the second time. A clear surface must also be applied with a clear coating. The coated parts have little effect on the flame retardant properties.
5. Drying: After coating, it can be dried at room temperature or baked at 60 °C for 30 min.
When choosing a spraying equipment, you can only avoid these misunderstandings, and proceed from the actual situation, combined with your own needs, to choose the equipment that is most suitable for you and the most efficient.