The Relation between the softness of Handle of Wool in the Greasy and Scoured States and Its Physical Characteristics

Abstract

Three sets of samples were submitted to panels of wool buyers for appraisal of handle, and partial regression analyses were carried out to determine the association of their grading for handle with their mean diameter, coefficient of variation ( C. of V.) of diame ter, number of crimps per inch, staple length, Young's modulus, yield, percentage of wax, percentage of suint, and percentage of dirt. In a preliminary experiment the mean gradings given by 12 appraisers to 36 samples, which varied in diameter from 18 to 27 μ, were analyzed. The important characteristics were found to be mean diameter, number of crimps per inch, and, in the greasy halves of the samples, the yield. The suint was the component of yield that affected handle. In the second experiment 66 samples varying in diameter from 16.6 to 31.6 μ were appraised by ten buyers, under more carefully controlled conditions. The gradings for handle in these appraisals appear to have been determined primarily by diameter and secondly by crimp, with staple length and C. of V. of diameter having a small influence. Neither yield nor Young's modulus were significantly associated with handle. In the third experiment 50 samples with a range of only 2.7 μ in diameter, but a range of 10 in number of crimps per inch, and of 28% in yield were appraised by five buyers who had not been concerned in the tests previously. Once again diameter and crimp, but not yield, had statistically significant associations with softness of handle. The results suggest that softness of handle should be used more frequently in con junction with the visual indication given by crimp for appraising fiber diameter.