93—STUDIES ON THE FELTING PROPERTIES OF SOUTH AFRICAN MERINO WOOLS

Abstract

A laboratory technique, closely simulating industrial practice, has been developed for the examination of the relative feltability of scoured Merino wools. The extent of feltability is evaluated in terms of breaking load and porosity to air of the resultant felt. Whilst it is confirmed that fine wools will give a less porous and stronger felt than coarse wools, it is also shown that the loss of porosity from the loose wool state to the felted state is greater for coarse wools. South African wools with a low degree of crimp in relation to fibre diameter, particularly exemplified by under-crimped copper-deficient wools, have a much greater feltability than wools with a high crimp/diameter ratio, and it has been found that the effect of an alteration in crimp number is of greater importance in determining feltability than is the effect of a corresponding alteration in fibre diameter. Weathered wools felt more than sound wools and the effect of weathering can be greater than the effect of fibre diameter. In view of contentions of the trade that Cape wools felt more than comparable Australian types, Australian wools have been examined in a parallel study. It is shown that fibre diameter and weathering play the same rô1es in the felting of Australian wools as in South African wools. The effect of crimp variations in the Australian wools is, however, much less pronounced, and this finding may be one of the explanations for the above contention.