Production Process of Coating Equipment:
As we all know, aluminum alloy surfaces have poor adhesion, and it is difficult to directly apply paint to achieve good adhesion. Even if the paint is applied, it will quickly peel off. So how can adhesion be increased? It is necessary to apply a primer on the aluminum alloy substrate to enhance paint adhesion, and then apply the topcoat.
I. Preparation and Conditions Before Spraying:
Weather Conditions: The paint must be applied in clear weather conditions. It is prohibited to work under conditions of rain, fog, snow, or significant dust. The spraying temperature should be around 25℃, and the humidity should be below 80% RH.
Substrate Treatment: The aluminum alloy substrate should be sanded and oxidized. The surface should be derusted, degreased, and kept clean and dry, free of contaminants. Dust should be removed and the surface leveled before painting. Ensure that the substrate is dry before spraying.
Spray Gun Standards: A spray gun with a nozzle diameter of 1.5-2.0mm should be used. The spray gun pressure should be adjusted to 3-4 kg/cm². Adjust the spray width to medium air pressure of 3-4 kg/cm², and try to wet the workpiece surface evenly with 2-3 coats. Adjust the paint flow appropriately; if the flow is too low, particles may appear on the paint film surface.
Air Compressor: Before starting, the air compressor and filter should be drained to avoid pinholes in the paint film.
II. Primer Spraying:
After achieving a good surface treatment effect on the aluminum alloy (free of oil and dust, with a certain roughness on the surface), an epoxy zinc-rich primer specifically for aluminum alloys can be applied. This primer has good adhesion to aluminum alloy surfaces, especially the two-component epoxy zinc yellow primer. This paint has excellent adhesion, flexibility, and hardness characteristic of epoxy paint and has good compatibility.
Mixing Ratio: Primer: Primer hardener: Thinner = 4:1: appropriate amount. Stir the paint for 5 minutes until uniform before mixing. Use a precise electronic scale to weigh according to the mixing ratio to ensure accuracy. After mixing the paint, stir with a clean aluminum or iron rod until completely uniform. Be careful not to mix in other types of paint, solvents, etc., and maintain a clean spraying environment. Use the mixed paint within 2 hours. If the ambient temperature exceeds 30℃, the usable time after mixing will be shortened.
To achieve the best effect, spray twice.