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Common drawbacks of general paint coating


Orange peel: When the coating film is dried and hardened, a partial or all orange-skinned surface is formed on the surface of the coating film.

  There are many reasons for producing orange peel. In summer, the temperature of the construction environment is high, and the solvent evaporates quickly. As a result, the coating of the coating machine has been dried during the leveling process. It is recommended to add an appropriate amount of slow-drying water when mixing the paint. Reduce the drying speed.

  However, it should be noted that slow dry water cannot be added excessively, otherwise the gloss of the paint will increase, the drying will be slower, affecting the later stacking and packaging of the workpiece, and affecting the shipping time.

  In addition, the high viscosity of the paint spray coating will also cause this phenomenon. Adjusting the proper spray viscosity and oil output is also a very important factor.

  Pinhole: The bubble is enclosed in the wet coating liquid during the coating process, because the bubble is difficult to volatilize and escape, the wettability of the wet coating film and the object to be coated is poor, and some or all of the surface of the coating film appears tiny holes, the spraying ratio Dip coating and shower coating are more prone to pinholes, and oily system coatings with excellent wettability have less chance of pinholes.

  During defoaming, the bubbles migrate from the bottom layer of the wet coating film to the surface. Due to the high temperature of the construction environment, the coating film is too thick, the bubbles are not completely detached, and the coating film is already dried, so that the passage of the bubbles cannot be leveled, and the bubbles cannot be completely Pull out to create a pinhole.

  At this time, it is necessary to adjust the drying speed of the paint, the proportion of the curing agent can be appropriately reduced, and a small amount of slow-drying water is added, but it is necessary to pay attention to the fact that the proportion of the curing agent is not too low, so as to prevent the paint film from being completely dried, and the paint film becomes soft. The scratch resistance is deteriorated.

  Whitening/whitening: The humidity of the air is too high, and the solvent in the coating film volatilizes and absorbs heat, so that the air temperature on the surface of the coating film is lowered to reach the dew point, and the condensation of water vapor penetrates into the coating film, causing the water vapor to be incompatible with the coating film to become milky white (partial or All).