Film prepative and inspection of Physical and Mechanical Properties - "Determination of membrane drying time"

The surface drying time measurement method of the coating film, the cotton ball method and the finger touch method (GB1728-79) stipulated in the national standard of our country, are similar in principle to the method specified in 501517-73 (sprinkling glass beads method), and both are practical. It is worth studying the measurement method of the actual drying time, because whether the coating film is dry or not will directly affect the accuracy of the measurement of physical-mechanical properties (such as hardness). 1503678-1976 is equivalent to GB1728-79, which stipulates that the actual drying time is determined by the filter paper method and the cotton ball method. The difference from GB1728-79 is: