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.