What Factors Affect the Gloss of Automotive Paint?
1. Glossy imaging
When the eye focuses on the reflected image of the light source, the image quality is evaluated, that is, the ability of the surface to reflect the object. The light source will appear bright or dull (gloss). Gloss is the visual impression obtained when evaluating a surface. The more light directly reflected, the more obvious the gloss feel. The smooth and high-gloss surface clearly reflects the image. The incident light is reflected directly on the surface and is highly glossy. On a rough surface, light is diffused in all directions, the image quality is reduced. The reflected object no longer appears bright, but is blurred. The more average the scattered light, the lower the intensity of the reflected light in the main reflection direction and the more obscure the surface, which is medium to low gloss.
2. Factors affecting gloss of paint
Paint is a chemical mixture coating that can firmly cover the surface of objects for protection, decoration, signage and other special purposes.
(1) Particle size
The particle size and dispersibility of the pigment in the paint will affect the gloss of the paint film. The finer the pigment, the better the dispersion uniformity in the base material, which helps to form a smooth paint film.
(2) Pigment concentration
The pigment-base ratio in paint has an effect on the gloss of the paint film. As the pigment particles in the paint film weaken the specular reflection, the gloss decreases. The gloss gradually decreases with the increase of the pigment volume concentration (P.V.C). When the pigment-base ratio is constant, the greater the oil absorption of the pigment, the lower the gloss.
(3) Paint color
The pigments of different colors absorb and reflect light at different degrees. Because black paint completely absorbs light and white paint completely reflects light, black paint shows higher gloss than white paint.
(4) Solvent types and flatness
The type of solvent used in the paint directly affects the speed of volatilization. Too fast or too slow volatilization will affect the flatness of the paint film and reduce the gloss of the paint film. The gloss of the paint film surface depends not only on the flatness and roughness of the paint film surface, but also the incident angle of light. The larger the incident angle, the higher the intensity of reflected light.
The standard board is the main benchmark for measuring and calculating the gloss of the paint film, which will directly affect the accuracy of the sample gloss measurement, so it should be carefully stored to prevent surface damage.
What are the reasons that affect the gloss of the paint? In the medium gloss area, the visual gloss is approximately linear with the instrumental gloss; in the high gloss area, the visual gloss is often lower than the instrumental gloss due to the sharpness of the reflected image; in the low gloss area, due to the different amount of pigment (matting agent) added and the roughness of the paint film surface, the visual gloss will be higher than the actual measurement result of the instrument.
3. Improvement of gloss and detection
Gloss cannot be improved: This has something to do with the raw materials used in the production of the paint. For example, the ratio of pigments and other additives in matte paint and gloss paint is different when added. The matte paint cannot be adjusted to a gloss paint after leaving the factory and the gloss can be reduced. An appropriate amount of matting agent can be added to the paint. This is always a powdery thing. Dilute it with a thinner and then add it to the paint a little. Every time you add it, use a blender to fully stir the paint. Then compare it with the sample. Remember to never add more! Finally, use a gloss meter to check whether the required gloss is achieved.
For the gloss test, it is recommended to use the Linshang gloss meter. The Linshang gloss meter is small and exquisite with accurate measurement. The measurement data is diversified. Maximum, minimum and average values can be measured. Linshang gloss meter makes the gloss value measurement more convenient.