Coating equipment production line: reasons for poor gloss

Coating equipment production line: reasons for poor gloss

The phenomenon where the gloss of the glossy coating does not reach the expected gloss after drying or the coating shows a decrease in gloss and a hazy haze shortly after coating is called poor gloss. The phenomenon of insufficient local luster and misty haze is called uneven luster.

Reason for occurrence:

1) Poor quality, mismatched or inappropriate proportion of curing agents and thinners, poor dispersion, and poor film-forming performance. If the resin dosage is insufficient or the miscibility is poor, the coating fineness is poor, the dispersion of pigments and fillers is poor, and the pigment volume concentration of the paint is high.

2) Severe flocculation occurs during the storage of pigments, and the coating contains moisture, impurities, etc.

3) The excessive amount of diluent added diluted the color of the original glossy paint.

4) Before use, the paint was not thoroughly mixed, resulting in less pigment and more paint in the upper half of the bucket, and there was a glossy finish after application; The lower half of the bucket contains more pigment and less paint, resulting in a dull finish after application.

5) The substrate treatment is not qualified, the substrate is too loose, and the absorption of the coating is large and uneven; The surface is rough, with impurities such as oil stains, moisture, wax, etc. remaining.

6) The substrate reacts with the coating, such as a new cement wall appearing alkaline and losing its luster due to saponification with oil-based coatings.

7) Thin topcoat or varnish, uneven coating surface, etc.

8) The impact of construction environment, construction in cold and humid climates, causes water vapor to condense on the surface of the paint film, resulting in a dull paint film; There is too much dust in the construction site or when encountering wind, rain, coal smoke, etc. during the drying process, the paint film is also prone to semi gloss or no gloss, especially for tung oil coating. If encountering wind and rain, this problem is particularly likely to occur.

9) Applying topcoat before the primer or putty layer is completely dry, and polishing before the topcoat is completely dry, can also cause loss of gloss.

10) The solvent or diluent is baked too early before it evaporates to a certain extent, and there is insufficient ventilation or high temperature during drying.