What is the cause of Coated steel Gloss?

There are two cases of poor gloss of color-coated boards. One is that the coating does not achieve the desired gloss or uneven color after curing, or after the coating is cured for a few hours, some of them produce gloss decline after two or three weeks. Backlighting occurs.

The second is that the color of the coating after curing is darker than expected or swatches.

cause:

(1) The reason for the coating formulation. Too much pigment, filler and solvent in the paint, insufficient fineness or dust;

(2) The surface of the substrate is rough or has oil, moisture, wax, etc., and the coating is not fully cured;

(3) Insufficient stirring before the coating is put on the machine, and the solid content of the coating sinks to the bottom of the bucket, so that there is less pigment in the working bucket during construction;

(4) Too much diluent is added to the paint, which dilutes the effect of the glossy paint;

(5) The top coat is too thin, and the roller coating room is too high or too low during construction;

(6) The temperature of the curing furnace is set too high, the amount of hot air circulation in the furnace is insufficient, and the coating is overbaked, which makes the eye color aging and causes the gloss to decrease.

Method of exclusion:

(1) Detect whether the fineness of the coating on the machine meets the process requirements;

(2) The paint should be fully stirred and filtered before being put on the machine, and the diluent should not be added too much;

(3) Control the humidity in the roller coating room to prevent moisture from mixing into the coating;

(4) Check whether the thinner matches the paint, and ensure that the wet film thickness of the top coat cannot be too thin;

(5) The furnace temperature setting of each section of the curing furnace should be reasonable to avoid too high or too low.