STATISTICAL STUDY OF SIZE AND SHAPE-DISTR IBUTIONS OF DUST PARTICLES IN TEXTILE PRODUCTION SITES WITH SPECIAL REGARD TO FIBROUS PARTICLES

At various stages during the manufacture of textiles, fine grain dust particles are emitted due to mechanical stresses to the natural or syn thetic organic textile fibres. It was the scope of the reported invest igation to study the morphology of the dust particles, i.e. size and s hape, at industrial processing stages. A focus was set on the emission of fibrous dust particles according to the WHO-definition, i.e. parti cles with a diameter smaller than 3 microns, lengths in excess of 5 mi cron and an aspect ratio greater 3. Sampling and characterization was executed in general in analogy to well-proven methods developed with i norganic particles in mind. Due to specific properties of organic part icles, some modifications to these methods had to be made. The results show that textile dusts must be characterized by broad size and shape distributions. It was of interest, that for weaving processes - regar dless of material - a mean aspect ratio of approximately 1.75 was foun d. Between 0.5 and 6% of the airborne particles at the various process es were found to be fibrous dust particles according to the WHO-defini tion. It should be noted that, unlike mineral or other inorganic fibre s, organic 'fibrous' particles are of rather complex shape. The actual concentration of fibrous WHO-particles was below 0.2 fibres/cm(3) for spinning processes in yarn manufacture and even smaller for weaving p rocesses. In general, higher concentrations were found during the proc essing of natural fibres, while the concentrations during processing o f synthetic fibres were in some instances as low as the background of approximately 0.01 fibre/cm(3).