1. Introduction
Gloss is the optical property of the surface of an object, indicating the ability of the surface to reflect light. In the field of coating, coating gloss degree is coating surface to the light reflection ability, also known as the mirror luster. The gloss of the coating is not only related to the nature of the coating itself, but also affected by the incident light source and light Angle. Gloss divided into three categories, half light and light light, glossiness is suitable for the different needs of different coating, such as car paint, furniture paint, etc.

2. Relevant standards
GB/T 9754-88 and ISO 2813:1994 is the criterion for determination of gloss coating, rules for their use 20 °, 60 ° and 85 ° geometry Angle gloss measurement method.

The importance and method of measuring the gloss of paint film

3. Introduction of key test methods
3.1 GB/T 9754-88 do not contain metallic pigment paint film of 20 °, 60 ° and 85 ° specular gloss measurement

3.1.1 testing principle

Gloss meter using the principle of photoelectric determination of paint film on the surface of the mirror reflected light. Gloss meter is measured by the film within the scope of the Angle of the reflected light intensity, the intensity of light associated with the material and the light incident Angle of paint film. In determination of the light source, light through the lens into a parallel light, and then projected onto the surface to be tested at a certain Angle, Angle of the measured surface will reflect the same light, after lens converge into the cell, produce photocurrent, through the galvanometer can get luster of the readings.

The importance and method of measuring the gloss of paint film

3.1.2 Operation points

Sample preparation: Use a 100μm wet film preparator to spread the paint on the glass plate to ensure that the film is smooth.

Gloss determination: Three readings were taken at different locations of the test paint film parallel to the direction of coating, using a high gloss working standard plate to calibrate the instrument to ensure accuracy. If the error is less than 5 units, the mean value is recorded as the gloss value. Otherwise, three measurements were made and the mean and limit values of all six values were recorded.

The glass substrate: six times, in different area of the sample surface or direction measurement, record average and limit value. If the error is greater than 10 units or greater than 20% of the mean, the test plate is discarded or the mean and limit values are recorded.

3.1.3 Presentation of results

The gloss unit value at a certain Angle is used to indicate the gloss of the paint film.

The importance and method of measuring the gloss of paint film

4. Application and significance
The gloss measurement of paint film is an important method to evaluate the appearance and quality of paint. Gloss measurement results can help to understand the decorative properties, protection properties and surface smoothness of the coating, so as to ensure that the coating effect meets the design and quality requirements.

Conclusion 5.
Measuring the gloss of the film is the key method to evaluate the appearance characteristics of the film. The gloss measurement can objectively and accurately evaluate the gloss of the coating, so as to provide reliable data for the quality control of the coating project and ensure that the coating meets the requirements of the design and standard. Paint manufacturers and the coating industry can improve the quality and appearance of products with the help of gloss measurement methods.