Fineness unit conversion
Usually the fineness of the powder is expressed by "mesh", which is defined as the number of meshes in the area of 1 square inch, that is, the number of meshes in the sieve, and the number of meshes that the powder can pass through is defined as mesh number. The larger the mesh number, the smaller the particle size. Talc powder is usually divided into 400 mesh, 800 mesh, 1000 mesh, and 1250 mesh superfine talc powder according to the grade. Table 2 can be used to convert powder particle size mesh to micron.
Table 2 Conversion of powder particle size mesh and micron
Maintenance of fineness gauge
For the maintenance of the Fineness Meter, in addition to cleaning it in time during work, it is also necessary to avoid bumping, especially on the working surface. It is recommended to place the scraper next to it and rest it on the fineness board. The groove is knocked out of the gap. Due to frequent use, the blade of the scraper is also easily worn. When the blade is perpendicular to the shallowest groove of the fineness plate, if there is light passing through, it indicates that the edge of the scraper has been severely damaged. At this time, the measured value will be greater than the actual value. If the measurement error is caused, a new scraper needs to be replaced to ensure accurate measurement results.
For more details, please refer to the full text of "Discussion on the Treatment of Abnormal Coating Fineness" (Wang Fei)
