Detailed explanation of Fengli Group's core process of metal curtain wall spraying
The core process of metal curtain wall spraying mainly includes the following steps, which ensure the quality, durability and aesthetics of metal curtain wall coating:
1. Metal structure substrate treatment
1). Rust removal and cleaning: There may be scale, rust layer, oil stain, welding scar, spatter, burr and other attachments on the surface of metal components. If these attachments are not completely removed, they will cause the paint layer to pack and peel off, which will directly affect the adhesion and corrosion resistance of the coating, and reduce the service life and decorative effect of the paint film. Therefore, before spraying primer, these attachments must be thoroughly removed to make the metal surface smooth and smooth, without obvious pits and damages, and expose the metal luster.
2). Degreasing and phosphating: Degreasing is to remove grease, dirt, etc. on the metal surface to clean the surface of the object. Phosphating is to soak the metal in a solution containing phosphoric acid after degreasing, so that the metal surface is formed. A layer of phosphating layer. This phosphating layer can improve the corrosion resistance of the metal surface and increase the adhesion of the metal surface, which is conducive to enhancing the adhesion effect of the coating.
2. Apply primer
In the anti-corrosion coating system of steel structures, the role of anti-rust primer is crucial. It must not only have good adhesion to steel, but also play an excellent anti-rust effect. Commonly used primers include epoxy zinc-rich primer, etc. This type of primer has excellent anti-corrosion and wear resistance. When applying primer, it is necessary to ensure that there are no oil, dust, water, acid, alkali, etc. on the substrate. When the primer is two components, it needs to be stirred evenly in strict accordance with regulations before use. The coating method can be airless spraying, two coats, coating interval of 24 hours, and the dry film thickness is not less than 75μm.
3. Apply topcoat (fluorocarbon paint)
The main principle of fluorocarbon paint spraying is to use polyvinylidene fluoride resin (PVDF) as the main raw material, and then use polyurethane paint, acrylic ester paint and metal particles to make special water-based coatings. When applying topcoat, you need to pay attention to the following points:
1). Color difference control: In order to ensure the consistent color of the coating, raw materials should be purchased in batches, and on-site re-examination should be strengthened. The construction process should be strictly controlled, and mixing and spraying of different colors of coatings is prohibited. The raw materials should be stirred evenly before construction, and a dedicated person should be responsible for timely stirring. The uniform material should be handed over to the sprayer.
2). Spraying skills: Two people are required to cooperate when spraying. The spray gun worker is responsible for spraying, and the assistant is responsible for blocking and feeding. The spray gun worker should pay attention to the distance between the gun and the working surface within a certain range (such as about 25cm) and keep it perpendicular to the working surface. Avoid oblique spraying and repeated spraying when running the gun, keep your eyes on the sprayed place, and adjust the speed of running the gun at any time according to the effect of the sprayed place. The size of the gun nozzle and the air pump pressure should be matched, and keep the spraying pressure and paint consistency moderate to ensure the full atomization of the paint.
3). Environmental conditions: The construction temperature during spraying is required to be 5 °C ~ 40 °C, and the relative humidity is ≤ 80%. Construction in rain, fog, frost, snow, or strong wind weather is not allowed.
4. Quality inspection and acceptance
After the spraying is completed, the quality inspection and acceptance of the coating needs to be carried out. The inspection includes the thickness, adhesion, hardness, corrosion resistance, weather resistance, etc. of the coating. At the same time, the appearance of the coating also needs to be inspected to ensure The coating is smooth and smooth, with consistent color, no missing coating, no bubbles, no cracks and other defects.
To sum up, the core process of metal curtain wall spraying includes the steps of metal structure base treatment, primer coating, topcoat coating (fluorocarbon paint), quality inspection and acceptance. These steps are interrelated and interdependent, and together constitute the complete process system of metal curtain wall spraying.
