Floating color and blooming are two common paint film diseases in the production of recolor paint. The floating color is due to the different densities, particle sizes and wetting degrees of the various pigments used in the production of recolor paints, and the downward sedimentation speeds are also different during the formation of the knee film but the unfixed film. Pigments with large particle size and high density (such as chrome yellow, titanium dioxide, iron red, etc.) have a fast sedimentation speed, while pigments with small particle size and low density (such as carbon black, iron blue, phthalocyanine blue, etc.) Relatively slow, so that when the paint film is cured, the appearance color is not the uniform complex color we need, but becomes an unsightly paint film with small particle size and low density pigments accounting for the prominent color. Flooding is due to the difference in surface tension of different pigments and the difference in affinity with the paint, resulting in uneven distribution of pigment concentration on the surface of the paint film, and irregular mottling due to a local concentration of a certain pigment.
The main factors that affect floating color and hair blooming are:
① The surface state of the pigment and the resulting affinity between the pigment and the paint are different, poor wettability or high water content are likely to cause floating color and blooming;
②The particle size and density of the pigment are different, the bigger the difference, the easier it is to float;
③The internal surface tension is different when the paint is formed into a film.
The secondary factors that affect floating color and hair blooming are:
① The volatilization speed of the solvent and the amount of the solvent site, the slow volatilization of the solvent and the large amount of solvent are easy to produce blooming;
② The drying speed and pigment-base ratio of the paint, the slow drying of the paint and the small pigment-base ratio are easy to cause floating color and flowering;
③The thickness of the paint film, the thicker the paint film, the easier it is to float and bloom.
The solution is: in addition to selecting suitable pigments, paint materials, and solvents for the above reasons, increasing the viscosity of the paint liquid, the ratio of pigment to base, and controlling the thickness of the paint film. The way to get twice the result with half the effort is to use anti-flooding agent.
