ABSTRACT

In cotton spinning, one of the most critical problems, from the point of view of production economics, is trash content in the raw material. Cotton contamination influences production costs directly and indirectly. Moreover, trash content affects the quality of the produced cotton yarns, especially its evenness and the IPI per 1000 m.

There are many different measurement methods for the assessment of cotton contamination. They are still improving. Simultaneously, there are investigations on the development of new, fast and, at the same time, precise and objective methods allowing for the assessment the percentage of trash in cotton raw material as well as in semi – products originating from different spinning stages being carried out. It is required to use the obtained results from the existing methods for making conclusions on the spinning procedure, the number of waste and initial evaluation of predicted material costs of production.

In the Institute of Textile Architecture, research on cotton raw material processing effectiveness at a determined trash content is being carried out. We propose a parameter which can be used to predict the real yield from the given blend, as well as for the assessment and comparison of cotton blends at different proportions of the components. We also proposed a method for the assessment of a unit increase of raw material utilization due to the introduction of a component to the blend of high trash content, especially during processing of blends with cotton waste.

The proposed method can be used for negotiation of prices during cotton purchasing, taking into consideration two factors: predicted costs of raw material for producing 1 kg of yarn and if it is possible to achieve the price of produced yarn. The advantage is that it can be used for even small trade samples occurring in the cotton trade.