Due to the high degree of productivity and automation as well as the continuously increasing quality demands, cotton dust and trash content has become a crucial criterion in modern rotor spinning, particularly in fine count operations.

It is common knowledge that the practice of manual and visual classing not only insufficiently describes cotton characteristics bit sometimes will result in erroneous judgments concerning fiber quality and utility value of a specific cotton.

A quality operation based on technically and economically sound management decisions is only possible if raw material properties and their impact on and interactions with downstream production Processes are precisely defined. Among the objective, instrument-based testing methods for length, strength, elongation, fineness, maturity, stickiness and color, the quantitative and qualitative analysis of cotton impurities serves as one of the most important indicators of product quality and processibility.

The paper illustrates the sources of trash and dust and describes the influences of the nature of specific trash components on yarn quality and spinnability. The common methods of measuring trash and dust are introduced along with the relationships between measurement data and actual processing behavior of cotton fibers. On the basis of the ITV Dust and Trash Tester, empirical threshold values for residual sliver dust and trash content were developed and are discussed.