In the construction of imitation stone paint project, how to measure its drying time?

Recently, many friends have asked: in the construction of imitation stone paint, how to measure the drying time? Here, I will share with you today

Usually, we call the time from the fluid layer to the solid coating film formed by the imitation stone paint as the drying time, that is, the time required for the coating to change from viscous to solid coating film.

■ Dry time

The surface drying time of imitation stone paint refers to the time required for a wet coating of a certain thickness to change from a liquid to a solid on the surface under the specified drying conditions, but the coating

■ hard work time

Drying time means that the imitation stone paint has been completely dried to form a coating film, that is, under the specified drying conditions, the time required from the application of a certain thickness of liquid coating film to the formation of a solid coating film

The drying time is expressed in hours (h) or minutes (min).

1 Determination method of surface dry time

①Blowing cotton ball method Gently put a absorbent cotton ball on the surface of the coating, with the mouth 10~15cm away from the cotton ball, blow the cotton ball lightly in the horizontal direction, if it can be blown away, there is no cotton silk on the film surface, it can be considered that Surface is dry

② The finger touch method is to touch the surface of the imitation stone paint with your fingers.
If you feel a little sticky but no paint sticks to the fingers, the surface is considered to be dry
.
The surface drying time of building interior and exterior wall coatings is mostly measured by the finger touch method
.

2 Determination method of hard work time

There are many methods for determining the actual drying time of coatings, such as filter press method, cotton ball method, blade method, thick layer drying method, etc.
The determination of the actual drying time of architectural coatings often adopts filter press method and cotton ball method
.

①Press filter paper method Put a piece of qualitative filter paper on the coating film, the smooth surface is in contact with the coating film, and then gently place the dryer on the filter paper, while starting the stopwatch, after 30s, remove the drying tester, and turn the sample plate (coating film downwards) , the filter paper can fall freely, or tap a few times with the index finger of the hand holding the plate on the back, the filter paper can fall freely and the filter paper fibers do not stick to the coating, that is, the coating is considered to be actually dry
.
For paints whose coatings are allowed to be viscous in the product standard, if the filter paper still cannot fall freely after the sample is turned over and tapped with the index finger, place the sample on the glass plate, and hold the corner of the pre-folded filter paper with tweezers.
Gently pull the filter paper in the horizontal direction.
When the sample plate does not move, the filter paper has been pulled down.
Even if there are filter paper fibers on the coating, it is considered that the coating is actually dry, but it should be indicated that the coating is slightly sticky
.

② Put a absorbent cotton ball on the surface of the imitation stone paint coating, and then gently place the drying tester on the cotton ball.
At the same time, start the stopwatch.
After 30s, remove the drying tester and the cotton ball and leave it for 5min Observe whether the coating has traces of cotton balls and loss of light.
If there are 1 to 2 cotton threads left on the coating, which can be gently brushed off with cotton balls, it is considered that the coating is actually dry
.