Leveling properties of powder coatings

Talk about the main factors that affect the leveling of powder coatings:

First, the choice of pigment:

Before we match colors, we must not only match a variety of colors, but also take into account the amount of oil absorption and addition of various pigments, as well as their total proportion. The oil absorption of inorganic pigments is much smaller than that of organic pigments, so we can use inorganic pigments to adjust the color as far as possible to avoid organic pigments. The total proportion of various pigments should be adjusted according to the customer's covering requirements.

Second, melt viscosity:

For thermosetting powder coatings, in the process of melting flow, accompanied by crosslinking curing reaction, the higher the temperature, the faster the curing reaction, the faster the system viscosity rises, the shorter the flow time, and the leveling property is restricted. Therefore, when we choose a resin, try to choose a resin with lower viscosity and slower activity.

Third, leveling additives:

Adding appropriate leveling AIDS to the formula of powder coating can rapidly reduce the surface tension of the coating, promote the rapid flow of the coating before curing into film, and eliminate or reduce the surface defects such as orange peel, brush marks, ripples, and shrinkage holes.

Four, the selection of fillers:

As we all know, filling materials in powder coatings can not only reduce costs, but also improve the performance of powder coatings, especially wear resistance. But if our technicians choose the wrong filler, it can also give the powder leveling a fatal blow. In general, the oil absorption of barium sulfate is much smaller than that of calcium carbonate, kaolin, mica powder, quartz powder, silicon powder, etc. The smaller the particle size of barium sulfate, the higher the luster, the finer the particle size of other fillers, the larger the oil absorption, the worse the leveling.