47—THE EFFECT OF AGEING ON THE REMOVAL OF FATTY OILS FROM WOOL YARN

A laboratory study is described of the effect of ageing on the removal of fatty oils from wool yarn. When newly oiled yarn was scoured in package form, high and unevenly distributed oil residues were obtained, but scouring improved as the oil oxidized on the ageing of the yarn. The effect of ageing was of much less significance when the yarn was scoured in hank or fabric form because satisfactory scouring was obtained when the yarn was new. This improvement in package-scouring is associated with the droplet size of the emulsion formed during scouring. Unoxidized oil produces relatively large droplets, a large proportion of which are retained by the yarn during circulation of the liquor, which results in high and uneven residues. Oxidized oil produces many small droplets that are not retained by the yarn, so that low oil residues are thus obtained. In hank- and fabric-scouring, the liquor is not recirculated and hence the droplet size of the emulsion is of little importance.