Use standard sieve (<20 mesh and> 80 mesh standard sieve) to identify the particle size of washing powder, and not less than 75% of the particles are uniform. In the absence of a standard sieve, we can also use our senses to identify the particle size of the washing powder. The finished washing powder of good quality has a white color, uniform and full particles, dry and firm, free-flowing, and the size is about the same as the northern millet. On the contrary, if the particles are too fine, they will easily become dust, and the fluidity will be poor. If the particles are too large, the solubility of the particles will be affected. The diameter of the hollow granular washing powder is about 0.5-0.8mm, and the apparent specific gravity is about 0.25-0.45. The particles are uniform and do not stick or agglomerate.
