Coating technology: Determination of coating luster

Core tips: 1 Concept and quantitative principle of specular gloss Luster is an optical property of an object When the surface smooth material is illuminated by visible light, it will produce directional specular reflection The result of specular reflection makes the surface of material have luster, which is called specular luster, and the size of its reflection ability is called specular gloss The glossiness is determined by measuring the ratio of the reflected luminous flux to the incident luminous flux on the surface of the sample, that is, the light reflectivity The calculation formula is as follows: G=K× F2/F1 =100 Paint agent, top 10 Chinese wall paint brands Recommended introduction: interior wall paint and exterior wall paint can achieve beautiful, clean and pleasant effects, but the effects in different environments are different, so the color of the paint will be different There are ten brands of Chinese paint, ten brands of global paint, ten brands of Chinese wall paint, and ten brands of Chinese paint, Famous trademark of Chinese paint and coating In private rooms, most of us choose according to our own personality, personal hobbies and living habits The younger generation will choose the interior wall paint with rich colors and bright colors, while the older ones will have some working experience The concept and quantitative principle of specular gloss is a kind of appearance optical property of an object When the surface smooth material is illuminated by visible light, it will produce directional specular reflection The result of specular reflection makes the surface of material have luster, which is called specular luster, and the size of its reflection ability is called specular gloss The glossiness is determined by measuring the ratio of the reflected luminous flux to the incident luminous flux on the surface of the sample, i.e the optical reflectivity The calculation formula is as follows: g = k × F 2 / F 1 = 100 × ρ / ρ s (1) Where: G -- glossiness value of the sample; F 1 -- luminous flux directionally incident on the sample surface; F 2 -- luminous flux directionally received from the sample surface; K -- undetermined constant, k = 100 / ρ s ρ s -- reflectance of the standard plate; ρ -- reflectance of the sample; 2 Specified principle of measuring angle and standard plate Glossiness is characterized by the directional reflection of the object surface, so it is closely related to the measuring angle The principle of measuring angle is based on a large number of experiments on the correlation between the visual glossiness classification and the instrument According to Fresnel's formula, the results of measuring the specular gloss at different angles are different At present, the international standard adopts the black glass plate with refractive index of 1.567 and good surface polishing as the Standard Version, and the specular gloss value under various measuring angle conditions is defined as 100 Fresnel formula and formula (1) can be used to determine the glossiness value of the known refractive index black glass standard plate The specified principle and standard plate of the above measurement angle conform to the international standard iso2813 "paints and varnishes - Measurement Method of specular gloss at 20 °, 60 ° and 85 ° for non-metallic paint films", and are consistent with the requirements of ASTM D525 "measurement method of specular gloss" 3 The special gloss tester shall be used to test the gloss The test surface shall have a flat surface of at least 75mm-150 mm The irradiating hole of the instrument light source shall fit the surface of the test piece as much as possible For the test piece with brush mark or similar pattern effect, the direction of brush mark shall be parallel to the plane formed by the incident beam and the reflected beam Home of coatings is specialized in coatings, diatom mud, paint coating, coating technology, fire retardant coating news and coating, diatom mud, paint coating, coating technology, fire retardant coating decoration knowledge and decoration renderings,