The Proof Of The Pudding Is In The Eating, But We Have Only The Recipe To Go By

Cotton cost has always been the single major contributor to the cost of gray yarns. Consequently, economic cotton selection for meeting yarn specifications continues to be one of the main concerns of a spinner. Left to himself, any spinner would very much like to spin every single lot of cotton to yarn before deciding upon whether to buy the lot or not. This is because every spinner experiences occasional surprises, some pleasant, but some not quite, in taking decisions solely on the basis of laboratory test data. However logistics, commercial practices, need for prompt decision and so on rule out this most reliable appraisal of cotton. We are, most often, constrained to decide upon the purchase of cotton on the basis of fibre-test reports. We have only the recipe to go by; we don’t get to taste the pudding.

In reading meaning out of test reports of cotton, we have often, mentally, to balance the shortfall in one characteristic with the premium in another characteristic. Let us consider, for example, the two cottons in Table A-i.

Table A-i Data on Two Cottons

Cotton ZZ is shorter and coarser, but stronger than cotton XX. Which of the two cottons would be appropriate to spin NE 40 (15 tex) hosiery yarn? Again which of the two would be appropriate for NE 30 (20 tex) warp yarn? We can answer these questions only if we can complete Table A-ii by writing in the tenacity values without actually spinning the two cottons to yarns.

Over the years research workers have, therefore, expended considerable effort on the derivation of equations for the estimation of yarn tenacity from cotton fibre characteristics.