Table of Contents
Classification of powders according to I.P
1) Course powder:
Powders of which all particles pass through a sieve with a nominal mesh aperture of 1.70 mm (No. 10 sieve) and not more than 40.0 percent through a sieve with a nominal mesh aperture of 355 μm (No. 44 sieve) is called coarse powder.
2) Moderately Coarse powder:
A powder in which all particles pass through a sieve with a normal mesh aperture of 710 µm (No. 22 sieve) and not more than 40% through a sieve with a normal mesh aperture of 250 um (60 sieve) is called “moderately coarse powder.”
3) Moderately Fine Powder:
If all the particles of a powder pass through a sieve with a nominal aperture of 355 µm (No. 44 sieve) and not more than 40.0 % through a sieve with a nominal mesh aperture of 180 µm (No. &. sieve), it falls in this group.
4) Fine powder:
In case all the particles pass through a sieve with a nominal mesh aperture of 180 μm (No. 85 sieve), it is called fine powder.
5) Very fine powder:
If all the particles of the powder pass through a sieve with a nominal mesh aperture of 125 μm (No. 120 sieve), it is said to be a very fine powder.