用细度来判定彩涂板涂料性能指标

细度是测定彩涂板涂料内颜料、体质颜料等颗粒的大小和分散的均匀程度，单位以微米匀，对外观和装饰性能均起到美化作用，且有良好的力学性能等。 (pm)表示。彩涂板卷材涂料的背面漆和面漆对细度的要求均很高，一般控制在15~25pm，而底漆的细度则可以粗一些，一般控制在20-40pm。通常来说，细度小，能使涂层平整均细度的测定主要采用量程为 50um 的刮板细度计(见图 4-2)，检验方法及标准等效采用几种规格。另配有一把刮刀。双刃均磨光。 用国标GB1724-89(79)彩涂板涂料细度测定法。刮板细度计的构造为一磨光的平板，由工具合金钢制成。板上有一沟槽，在槽边有刻度线，分为0-50pm、0-100pm、0-150m等

测量时需要注意以下几点:
(1)根据不同涂料类型选用不同量程范围的细度计，可先用范围大的细度计粗测。(2)在测板上端滴人涂料样品1~2g左右，不要过多或过少。
(3双手握住刮刀，使刮刀与磨光平板表面垂直接触，以适宜的度由沟槽的深部向浅部拉过(一般用 3s 时间)，使试样充满沟槽而平板上不留余料。

(4)在阳光下迅速读数(不应超过 5)，使视线与沟槽表面成 15*-30°角，以出现三个以上颗粒均匀显露处读数为准。

Fineness is to measure the size and dispersion uniformity of pigment and physical pigment particles in coatings. The unit is micron, which beautifies the appearance and decoration performance, and has good mechanical properties. (PM) denotes. The fineness of the back and top coats of coil coatings is very high, generally controlled at 15 ~ 25pm, while the fineness of the primer can be coarser, generally controlled at 20-40pm. Generally speaking, small fineness can make the coating smooth and uniform
The measurement of fineness mainly adopts the scraper fineness meter with a measuring range of 50um (see Fig. 4-2), and the inspection method and standard are adopted
Several specifications. The other is equipped with a scraper. Both blades are polished. The national standard GB 1724-89 (79) was used to determine the fineness of coatings. The structure of the scraper fineness meter is a polished flat plate made of tool alloy steel. There is a groove on the plate and a scale mark on the edge of the groove, which is divided into 0-50pm, 0-100pm, 0-150m, etc
The following points should be noted during measurement:
(1) The fineness meter with different measuring range can be selected according to different coating types, and the fineness meter with large measuring range can be used for rough measurement first. (2) Drop about 1 ~ 2G coating sample on the upper end of the test plate, not too much or too little.
(3) hold the scraper with both hands, make the scraper contact with the surface of the polished plate vertically, and pull it from the deep part of the groove to the shallow part at an appropriate degree (generally takes 3S), so that the sample is filled with the groove and no residual material is left on the plate.
(4) Read quickly in the sunlight (no more than 5), so that the line of sight is at an angle of 15 * - 30 ° with the groove surface, and the reading at the place where more than three particles are evenly exposed shall prevail