This document specifies a method for the determination of the particle size distribution of coating powders by sieve analysis. Particle size distributions with a maximum of less than 100 µm is determined by laser diffraction, ISO 8130-13. This method is used especially for determining the oversize material or for the presence of contamination and can be used as a quality control procedure ("go"/"no go" test) by checking the amount retained on a single sieve.
The following particle sizes are typical for coating powders, however the particle size can deviate depending on the application:
— thin-film technology: 1 µm to 63 µm;
— electrostatic coating: 10 µm to 200 µm;
— fluidizing-bed method: 100 µm and above.
NOTE Sieves with a mesh size smaller than 32 µm are not practical and are likely to become blind during use.