In spite of the emphasis on the proportion of waste in the diagram, it is clear that the quantities to be expected here are relatively small. On average, about 6 - 8% primary waste, consisting of 50% good fibers and 50% contaminants, can be expected. About 90% of the good fiber elimination can be recovered as secondary raw material, and this still contains about 6% trash. Such secondary raw material can be mixed into the same blend up to a proportion of 2.5% without any effect on quality. Up to 5% can be blended with hardly noticeable changes in quality.
As far as possible, no more than 5% should be returned to the blend (for ring spinning).