30—THE INFLUENCE OF ORIGIN ON THE STRESS–STRAIN RELATIONS OF WOOL FIBRES

Stress–Strain data for wool fibres of different origin are presented, the tests having been made under different moisture conditions. Small differences exist between wool fibres from primary and secondary follicles from the same animal, the secondary being easier to stretch both initially and finally under wet conditions. However, the relative yield slope is markedly higher for secondary than for primary fibres. Differences exist between and within breeds in the initial modulus, the stress at 15% extension, and the slopes of the curves in the yield and post-yield regions.     

10—THE USE OF FLUORESCENT STAINS FOR THE STUDY OF THE STRUCTURE OF ANIMAL FIBRES

An account is given of the use of fluorescence microscopy for the study of the structure of various animal fibres. Sections of wool, mohair, llama, cow-tail, and horse-tail fibres, which were either untreated or had had some chemical treatment, were stained with fluorescent stains; much more detail was shown by this technique than by other staining methods. Basic dyes (acridine orange, rhodamine B, rhodamine 3GO, and thioflavine T) stained the orthocortex and acid dyes (uranin and geranine G) the paracortex.     

The Mechanical Properties of Wool Fibres and the Influence of Fibre Structural and Dimensional Variation: The Stress–Strain Behaviour at Varying Humidities—Reply

It is shown that the quantity of water mixing into the air-flow is an insignificant proportion of the total amount of water used in the air-jet texturing process and that this has a negligible effect on the air-flow in the texturing nozzle. It is suggested that only a fraction of this water is needed to impart the desired effects of wetting. Experimental investigations show that water acts as a lubricant to reduce the filament–filament and filament–solid-surface friction and hence aids the longitudinal displacements of the filaments relative to each other. A realignment of the yarn path minimizes the friction between the filaments and solid surfaces.