Three minutes! Seconds to paint knowledge of the little man ( II. )

After so many years of exposure to paint, do you really
the
TA?
3 minutes, Jotun takes you seconds to change
paint knowledge
Xiaoda people
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rowing
heavy point
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Q 1: Surface treatment is important for paint construction?
Before the construction of paint, the substrate needs to be surface-treated for two main purposes: first, to remove the surface of the relatively loose rust, garbage, etc., and secondly, to produce a relatively uneven micro-shape on the substrate surface, so that the paint can better penetrate the substrate surface, thereby increasing adhesion.
the surface treatment is critical to the final coating quality. Poor surface treatment, very easy to lead to paint film shedding, cracking, foaming and other paint diseases,
the
. Survey data show that 60-80% of coating defects are caused by improper surface treatment. As the coating industry goes as the saying goes: three points of paint, seven points of construction!
main methods of surface treatment include sand blasting and polishing.
Blast is powered by compressed air to form a high-speed injection beam that sprays the material (copper ore, quartz sand, gold sand, steel sand) at high speed to the surface of the work piece, resulting in a certain degree of cleanliness and different roughness on the surface of the work piece. The blast treatment consists of Sa1, Sa2, Sa21/2, and Sa3.
grinding refers to the use of hand (shovels, sandpaper, wire brushes) and power tools (grinding gun) to clean up contaminants on the substrate surface, including St2 and St3 treatment grades.
Q 2: Did the weather have a big impact on paint construction?
paint construction, the humidity and temperature of the surrounding environment have a very large impact. If the relative humidity of the environment is too high (greater than 85%, foggy, rainy days and other high humidity environment), the substrate surface will have a layer of water vapor, so that the treated surface flash rust, resulting in poor binding force of the paint film, easy to fall off;
So to carry out coating work, there should be two necessary conditions:
the relative humidity of the environment does not exceed 85%
the substrate temperature is 3oC
Q 3 higher than the dew point: what should I do when the paint bucket is opened?
paint is a mixture of resins, pigments, additives and solvents, after a long period of transport and storage, some solid components will sink to a certain extent, forming a layering. This does not mean that there is a quality problem with the paint, nor does it affect later use.
for single-part paint, stir thoroughly before deployment to make it even. It is best to stir with a power mixer.
For two-pack paint, stir the A part (base material) evenly, then pour the B part (curing agent) into the A part with the continuous stirring of the A part, and then continue stirring until even. Not the whole barrel deployment, should pay attention to the A, B parts of the ratio, the specific ratio of the product labels and instructions.
Q 4: What are the construction methods of paint?
brush coating is a traditional construction method, it can save paint, and simple construction, simple tools, flexibility, a wide range of applications. Brush coating has good permeability, wetting, forcing the coating into the surface of the steel plate. However, the construction speed of brush coating is slow, and a brush coating film is low, it is necessary to brush multiple times in order to reach the specified paint film thickness. Therefore, the brush coating is suitable for corner pre-painting and small area maintenance.
roller coating is the use of rollers to extract paint rolling on the surface of the workpiece coating method. Roller coating on a wide, flat surface has advantages, than brushing efficiency is much higher, and simple operation, semi-skilled workers can also obtain more satisfactory results. However, the surface permeability and wetting of roller coating are relatively poor, and are not recommended for the construction of first-degree paint. Therefore, roller coating is suitable for the construction of intermediate paint and finish paint for larger area flat steel.
coating is the best method for fast surface construction over large areas and for most coatings to achieve the most uniform construction in almost all situations. Spraying is also divided into air spray and high-pressure airless spray.
air spray equipment:
air spray, the coating is atomized by compressed air and transported with air flow to the component surface. The resulting paint film film thickness is uniform, smooth and flat, can achieve the best decorative effect. Therefore, suitable for surface effects require high equipment or components, such as mechanical equipment. It is also suitable for the construction of aluminum paint.
high-pressure airless spray equipment:
high-pressure airless spraying, the paint does not use compressed air atomization, but compressed paint is released from the nozzle of the gun, this sharp reduction in pressure causes the paint to expand sharply into fine particles, sprayed to the surface of the component to form a paint film. The production rate of high-pressure airless spray is fast, and most coatings can achieve thicker paint film after one spray, which can greatly improve the construction efficiency. Therefore, suitable for large-area component spraying, and suitable for all kinds of primers, intermediate paint, paint and other paint spraying.
Ends
(Source: Jotun Industrial Protective Coatings Retail Business)