June 9, 2021

Coatings with strong polar solvents are applied

The reason of flat head self tapping screw Manufacturer this matter is:

(1) The supporting function of the coating is not good, and the primer and topcoat are not matched. Coatings with strong polar solvents are applied to the surface of coatings made from less polar solvents. For example, in the alkyd paint or grease paint upper coat nitrocellulose paint; rosin-containing resin film after the addition of lacquer; coating on the oil paint alkyd paint; alkyd or grease paint coated with oxidized rubber paint, Polyurethane coating and so on. The penetration and swelling of the paint by the strong solvent make the base coating film bite.

(2)The coating is not dry enough to coat the next coating. If the vinyl chloride lacquer or varnish is not dry, apply a second coat of paint.

(3) When applying a top coat or under coat, select a strong diluent to swell the primer.

For the reasons for the above growth, we may wish to organize the following procedures to prevent and control:

(1)Strict coating with paint instructions book. Common paints of the same type can be used as one another. Different types of paints are formulated to comply with the rules of hard and soft; such as primers using strong solvent coatings (epoxy, polyurethane, etc.), topcoats with weakly soluble coatings (chlorinated rubber, alkyd, phenolic, etc.). Adding lacquer to the rosin resin paint film is suitable for splitting. If it is to be painted, it must be selected by polishing control, brushing the filter layer, and then using a clean rag to remove surface leaching particles, polishing with sandpaper, and then painting. Large paint.

(2)The paint should be dried thoroughly. It should be performed according to the best painting interval and must reach the shortest coating interval. During construction in winter, it may be appropriate to delay the painting interval to ensure that the primer is solid. For special types of coatings, a “wet-on-wet-on-wet” coating process can be used. When the first layer is not applied, a layer is applied immediately, which can increase the adhesion of the coating.

(3) The thinner used for painting the coating shall not exceed 5% of the total coating amount. The variety shall also be fixed during the coating process. A weak polar diluent may not be used at the bottom layer, and a strong polar solvent such as acetone may be used for the top layer coating. , esters and high boiling point aromatic solvents.

(4) To defensively bite, the first coat should be thinner. After the paint is completely dry, it must be coated with a second coat. It cannot be over-coated at a time, so that the solvent cannot be evaporated and the drying time can be prolonged.

(5) Coatings that fail to “bite at the end” cannot be revived to cover and make up. Should be shoveled to bite the bottom of the coating. Supplementary coating and reform support. After the primer is dry, apply the top coat after the primer has dried.