Water-based coating interpretation of aluminum alloy

Aluminum is a very characteristic metal. When it is oxidized by air, a dense layer of alumina is formed on the surface. This layer of film has excellent corrosion resistance
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. It's not like steel can be corroded all the time. Therefore, the aluminum alloy painting is only decorative effect. However, ordinary paint is difficult to attach to aluminum alloy, aluminum alloy surface must be treated in order to spray. Aluminum alloy surface adhesion is poor, alcohol-acid paint and other ordinary water-based paint is difficult to drink aluminum surface has good adhesion, even if reluctantly applied, soon fell off. So, aluminum alloy, aluminum plate and other substrates, how should be coated with water-based paint?
First: Surface Treatment
Pre-surface treatment of commonly used aluminum alloys with water-based paint: 1-1.5 hours of degreasing by immersing aluminum alloy parts in a degreasing solution made with surfactants and water preparation; Wash for 3-5 minutes; after cleaning, immerse in a passivar made with herbal acid, ice acetic acid and water for surface passivation for 1.5-2 hours; then immerse in another clearing tank to clean for 3-5 minutes; and remove and dry after cleaning.
Second: Aluminum alloy primer
after achieving good surface treatment on the aluminum alloy surface, (no oil, no dust, a certain roughness of the surface), aluminum alloy special epoxy zinc-rich primer can be sprayed. Epoxy zinc-rich primer has good adhesion to aluminum alloy surfaces, especially the two-part zinc epoxy yellow primer. The paint has the unique high adhesion, toughness, hardness and so on, and the supporting performance is good. The aluminum alloy surface is sprayed with epoxy-rich zinc primer: it can be sprayed according to the general construction method of the two-part primer. Namely: paint, ripe, adjust the viscosity of water-like paint, spray. For best results, spraying can be performed in two parts.
the first spray of the world - fog spray
1. Viscosity - 14-16 seconds (20 degrees)
2.Spitting - 1/2-2/3
3. Coating pressure - 4.0-5.0Pa
the distance of the spray tool - 25-30cm
5.standard spray - when fully open
6. Spraying - slightly faster
scattered and thin fogging the whole, with the lower coating film preliminary fusion. At the same time confirm whether there is a shrink hole part, if there is, the part slightly higher air pressure (6.5 bar), centralized spraying to fill the shrink hole.
second spray - primer spray
1. Viscosity - 14-16 seconds (20 degrees)
2. Spitting - 2/3-3/4
3. Coating pressure - 4.0Pa
4. The distance of the spray tool - 25-30cm
5.standard spray - when the spray is fully open
6. Spraying - slightly faster
the second spray is colored. Don't care too much about spray marks and metallic spots, light spray a layer can be, set the color. The spray tool moves a little faster, so repeat the spray once.
Three: aluminum alloy paint
aluminum alloy paint selection has a variety of options, room temperature self-drying paint varieties are: acrylic polyurethane paint, polyurethane paint, fluorocarbon paint and other most commonly used, in addition to epoxy paint, chlorinated rubber paint, perchloroethylene paint and other applicable to special environments of anti-corrosion paint.
spraying method
first spray - fixed color spray
1. viscosity - 14-16 seconds (20 degrees)
2. Spitting volume - 2/3-3/4
3. Coating pressure - 4.0Pa
4. Spray tool distance - 25-30cm
5. Standard spray - full open
6. Spraying time - slightly faster
the first spray for coloring. Don't care too much about spray marks and metallic spots, light spray a layer can be, set the color. The spray tool moves a little faster, so repeat the spray once.
can solve the problem, if the color is not enough, you can press the spray method once, and then spray again.
second spray - correct the spray
1. Viscosity - 11-13 seconds (20 degrees)
2. Spitting - 1/2-2/3
3. Coating pressure - 4.5-5.0 bar
4.. The distance of the spray tool - 25-30cm
5.standard spray - when the spray is fully open
6. Spraying - slightly faster
this spray is a paint stain and spray marks left after the fixed color spray, and make the mechanical texture better display.
and finishes are sprayed at intervals of about 16-24 hours. Between the two primers, and between the two finishes, the table dry can be sprayed, usually about 1-2 hours.