Role of fibre length variation in staple strength of Merino wool (Reprinted from 10th International Wool Textile Conference, 2000)

Sixteen fine wool Merino wethers were run as a single flock and at shearing , mid-side and dye-banded wools were collected. Fibre diameter (FD), standa rd deviation (SD) of FD, coefficient of variation (CV) of FD, staple streng th (SS), staple length (SL) and FD profiles along the staple were measured on the mid-side wool samples. Dye-bands for spring wool growth were cut fro m staples and snippet fibre length (FL) and FL variation determined. Small staples were drawn from the mid-side samples, and FD, minimum and maximum F D along the fibre, and staple FL were determined using the Fibre Profile Me ter. CV of staple FL for fibres longer than SL was significantly related to snip pet CV of FL (r=0.62, P=0.010). CV of snippet, and staple FL for fibres lon ger than SL, were both significantly related to SS. CV of FL for fibres lon ger than SL, square root of the sum of across and along FD SD2, and minimum FD along the fibre accounted for 84% of the variation in SS. Average stapl e FL was not related to calculated average FL from snippet samples. Staple FL and FL variation could be predicted from staple FD parameters. Wool stap le snippet samples underestimated the number of fibres shorter than SL.