Drying time and applicable standards of coatings

The whole conversion process of paint from liquid film to solid film is called drying. The national standard divides the drying degree into two stages: superficial drying and actual drying.

GB/T 1728-79(86) Measuring the drying time of the meter with the finger contact method: If you touch the surface of the film with your finger, if you feel that the finger is slightly sticky, but the paint does not stick to the finger, the surface of the film is considered to be dry.

GB/T 67.53.6-86 Use small glass balls to measure surface drying time: pour 0.5g of small glass balls with a diameter of 125~250um on the film of 50~150mm, and then gently brush off the small glass balls. The film surface was considered dry if the glass spheres did not damage the film surface.

The actual drying time was determined by filter paper method, cotton ball method and leaf method. Place filter paper or cotton balls on the membrane and pressure dry the Tester. If the film is free from fiber or tampon marks and light loss within the specified time, it is considered the actual drying time.