Dry sharing! The coating knowledge is full of questions and answers.

Q
why is it best to use primers for bottom filling in the paint process?
A
because the primer, specifically for filling as the main purpose of the formulation design, has excellent filling and polishing, and low cost, and if the paint to do the bottom filling, filling efficiency, and high cost.
asked
why should the primer be thoroughly polished before coating the finish?
A
1, enhance its adhesion
2, the paint has a strong follow-up, such as primer uneven, then the paint coating, coating effect flatness difference


answer
should completely fill the wooden eye, that is, by polishing can get a flat paint film effect.
asked
what are the criteria for thorough polishing of the primer?
answer
1, 450 angle to see the lightless bright spots
2, hairy glass

why do you need to fully stir?
the
paint is a mixture of resins, pigments, solvents, etc

. It is not a solution. In the meantime, pigments, light paint in the prime powder, such as scattered in the paint liquid. Therefore, usually in the storage process will have a certain degree of sinking, the formation of the usual paint layering. So the paint needs to be stirred thoroughly before deployment. (Must be stirred paint is: varnish, transparent colored surface, paint-free, beautiful paint, wood-print treasure)

how do you think of the paint yellow resistance?
the
paint yellow change is the characteristics of paint, not disease. Therefore, the yellowing of the paint is relative and not absolute. PU paint, general yellow-resistant and yellow-resistant paint, usually light plate selection of yellow-resistant, dark plate selection of general yellow-resistant paint.
Q:
water content of wood affects the quality of the coating?
A:
Undrided wood contains a lot of moisture, at low temperature, high humidity, wood absorbs moisture in the air and expands, high temperature, low humidity, the water in the wood gradually evaporates and shrinks outwards, but the wood in all parties upward shrinkage and expansion rate is different. Longitudinal minimum, radial large, string maximum. When the surrounding air condition changes, the moisture content of the wood also changes, causing the wood to expand or contract. The water content of general wood should be controlled at 8112%. If the moisture content exceeds the controlled moisture content, the wood of the furniture appears moist, the coating is dry and slow when applied, which will reduce the adhesion of the paint film, and will make the hair style such as nitro paint white. It will cure dry paint, such as PU paint to produce bubbles, pinholes and other paint film defects. When the climate is dry, the water contained in the wood evaporates and shrinks, easy to produce cracks, so that the surface of the paint film damage, therefore, the wood to make furniture must be dried treatment, water content should be controlled within the prescribed range. In addition, wood white blanks must be effectively closed before making primers, such as the use of China Resources PS900 bottom to prevent water and other substances in the wood from spreading outwards, is conducive to prevent wood deformation, paint film foaming, pinholes and other phenomena. It also helps to dry after grinding to remove wood hair and other effects.
Q:
the spray nitro paint (NC) paint film will be whitened, how to prevent whitening?
A:
coating in the film after the paint film presents turbid or milky white phenomenon called paint film whitening, also known as whitening, whitening, al whitening and so on. The original trapping analysis of the whitening of the paint film when the nitro paint is sprayed is as follows:
1, the nitro paint itself has very good solvent release, the solvent evaporates into the atmosphere in NC paint, which is easier than in other paints;
2, NC paint formula contains more volatile faster solvents;
3, such as high temperature environment, solvent volatile faster;
4, solvent rapid evaporation, absorbing the newly sprayed NC paint film wet film internal energy, so that the wet film surface temperature instantly dropped 21-30C, providing "condensation" occurred in the "cold bed";
5, high temperature and high humidity environment, so that the wet film around the high content of water vapor quickly in the "cold bed".
6, micro-water beads and wet membrane of the bad mixing, resulting in turbidity or milky white phenomenon, known as "whitening."
above 1, 2, 3 are prerequisites for whitening, 4 is the intermediate process, 6 is the final result. After the whitening phenomenon occurs, some appropriate warm-up (e.g. with light can make the whitening disappear, restore as before.) Some are irreversible, always white, the reason is unknown.
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