Measurement of hairiness of jute yarns by discrete and integral methods

Hairiness of wrap-spun and conventionally-spun (both slip draft and apron draft) jute yarns has been determined by 'integral' and 'discrete' methods. The integral method, based on Uster yarn hairiness index, measures the 'total hairiness' of the yam while the discrete method, based on counting the number of protruding fibres of different hair lengths, measures the 'long hairiness' of the yarns. It is found that both 'total' and 'long' hairiness of wrap-spun jute yarns ale appreciably lower than those of conventionally-spun jute yarns. When the data of wrap-spun and conventionally-spun jute yarns are pooled, the correlation coefficient between integral and discrete methods is positive and significant, but no relationship can be established when the results of only wrap-spun yam are considered. This is due to the difference in the structures of wrap-spun and conventionally-spun jute yarns. In the case of wrap-spun jute yam which was wrapped by either monofilament or multifilaments, the structure of the staple fibre assembly is close, compact, parallel and smooth while in the case of conventionally-spun jute yarn, the staple fibre assembly is open, bulky, helical and fuzzy.