Rieter

Definition

Index

Dust consists of small and microscopic particles of various substances, which are present as suspended particles in gases and sink only slowly, so that they can be transported in air over substantial distances. In accordance with a classification system established by the International Committee for Cotton Testing Methods ( ITMF), the following types are to be distinguished:

PARTICLE SIZE    

(μm)

Trash
above 500
Dust
50-500
Microdust
15-50
Breathable dust
below 15

A paper published by the International Textile Bulletin  [4] indicates that microdust consists of 50-80% fiber fragments, leaf and husk fragments, 10-25% sand and earth, and 10-25% water-soluble materials. The high proportion of fiber fragments indicates that a large part of the microdust arises in the course of processing. Mandl  [5] states that about 40% of the microdust is free between the fibers and flocks, 20-30% is loosely bound, and the remaining 20-30% is firmly bound to the fibers.