Paint film crack is a representative damage phenomenon of paint film in use. Common cracks include strip cracks, fork cracks, network cracks, cracks, bending cracks and other irregular cracks. To describe the severity of cracks in words, the method is as follows:
(1) Describe the shape of the crack in words.
(2) According to the depth of cracks, it can be divided into mild cracks (invisible to the eyes , but visible under a four-fold magnifying glass), moderate cracks (visible to the eyes, but not too obvious), and deep cracks (visible to the eyes). Obviously visible) and serious cracks (cracks deep into the bottom layer, that is, primer or bottom plate) and so on.
(3) According to the evaluation of the distribution area of cracks, it is expressed as a percentage of Xiangban.
(4) Evaluate according to the density, that is, there are dense (expressed by D), dense (expressed by MD), medium (expressed by M), and sparse (expressed by F).