Лако-красочные материалы — производство

The size of the particles depends also, like the particle shape, on the manufacturing conditions and varies from a few pm up to 100 pm, depending on the optical effect required and the application conditions.

The fineness of the pigment is characterized by the maximum particle size (men­tioned in the catalogues as sieve residue according to standardized DIN or ASTM testing methods) and the average particle size D50 measured preferably by laser beam diffraction methods. These methods are not yet standardized and the read­ings depend very much on the equipment and the testing conditions. Furthermore the particle size distribution can be characterized by the “span”, i. e. the width of the distribution curve.

5.3.2.4