1. Introduction

The drying process of paint is an important link in the construction of paint, and the drying time of paint is directly related to the construction period, the quality of coating film and the control of project progress. This paper will introduce the drying time determination of paint film and putty film, as well as its definition, purpose and significance.

2. Definition, purpose and meaning

Drying refers to the process of transforming the paint from a liquid coating to a solid coating. The drying process of coatings can be divided into three stages: surface drying, actual drying and complete drying. Usually, only the surface drying time and actual drying time of the coating are measured. Surface drying time refers to the time of film formation of liquid coating surface under specified drying conditions. The actual drying time refers to the time when the entire liquid coating layer becomes a solid coating under the specified drying conditions. Accurately measuring the drying time of the coating helps the construction unit to control the construction period, and is also an important means to ensure the quality of the coating film.

Summary of drying time determination of paint film and putty film

3. Introduction of key points of inspection methods

3.1 GB/T 1728 paint film, putty film drying time determination

3.1.1 Materials and instruments

Drying time tester

Constant temperature and humidity equipment

Electric blast drying oven, etc

3.1.2 Operation Points

The surface drying time can be measured by blowing cotton ball method or finger-touching method. A method (blowing cotton ball method) is to gently blow the absorbent cotton ball on the surface of the paint film, if it can blow away and leave no cotton silk, that is, the surface is considered dry. Method B (finger touch method) is to touch the paint film surface with the finger, if it feels sticky but no paint sticks to the finger, it is considered that the surface is dry.

The actual drying time can be determined by pressing filter paper, pressing cotton ball, blade or thick layer drying method. A method (filter paper method) is to press the tester on the paint film, remove it after 30 seconds, if the filter paper can fall freely, it is considered to be actually dry. Method B (cotton ball method) is to press the tester on the paint film, remove it after 30 seconds, no cotton ball traces and loss of light phenomenon, it is considered to be actually dry. The C method (blade method) is to use a blade to scratch the paint film, observe the bottom and the film, if there is no adhesion phenomenon, it is considered that the actual dry. Ding method (thick layer drying method) is to remove the dried test block from the aluminum sheet box, there should be no mucus at the shear, the shear surface is closed and then pulled apart, and there is no wire drawing phenomenon, it is considered that the actual dry.

Summary of drying time determination of paint film and putty film

3.1.3 Result representation and result judgment

Record the maximum time it takes for the surface to dry, usually in hours or minutes. Check whether it passes according to the specified dry time.

Record the maximum time it takes to actually dry, usually in hours or minutes. According to the specified working time to determine whether to pass.

4. Application and significance

The drying time determination method of paint film and putty film is of great significance in paint construction and quality control:

Construction control: Knowing the drying time of the coating helps the construction unit to arrange a reasonable construction period and improve construction efficiency.

Coating quality: The drying time is directly related to the quality of the coating film, and controlling the appropriate drying time helps to avoid the problem of insufficient or excessive drying.

Product development: By measuring the drying time, coating manufacturers can optimize product formulation to ensure stable and consistent coating performance.

Summary of drying time determination of paint film and putty film

5. Conclusion

The drying time determination of paint film and putty film is an important link in paint construction and quality control. Through the appropriate operation method and equipment, the drying time information can be accurately obtained, so as to ensure the quality of coating construction, improve the construction efficiency, and ensure the coating film performance. This is of great significance for the production and application of coatings.