FOOL WHY NATURAL FIBRE SURPASSES SYNTHETICS

Press, Volume LXXXVII, Issue 26441, 7 June 1951, Page 6

FOOL WHY NATURAL FIBRE SURPASSES SYNTHETICS

rn or. i. O.

(Reprinted bv arrangement with the "Sydney Morning Herald.")

Hardly a month passes these days without the announcement of some novel textile fibre, and ® ac, v new announcement tends to outdo the last by the extravagance of the claims made by it. Occasionally these claims are made on behalf of a product which has still to be tested commercially, and many an idea fails to survive this test. Sometimes, however a new synthetic fibre comes into full production, as rayon and nylon have done Why, then, is it that wool, instead of slipping from favour, is in keener demand than ever? The variety and interest of the many textures and colours which wool cloths exhibit, their exquisite draping qualities, and the reputation of wool as a <l uallt y fabric may explain the continuing demand for it for Civilian and especially fashion uses. . But how shall we explain the insistence with which military authorities throughout the world demand that their forces shall go into battle clothed largely in wool? Here, only sheer merit as a clothing fibre can explain wool’s success. IxMwe StrnDhir® First, wool fabrics are warm. This is not because wool fibre is a baa conductor of heat, but because wool fabrics are exceptionally loose and open, containing a minimum of fibre and a maximum of entrapped air. This looseness of structure derives from the way in which wool fibres are crimped or waved, so that two fibres cannot easily lie closely together in intimate contact, as can straight fibres. Moreover, since this crimp is grown into the fibre while it is being formed on the sheep’s back, it is permanent. Textile scientists have been able to show that if a fabric is to remain loose and bulky—and therefore warn -it must be made from fibres which are easily stretched, but difficult to twist. Only wool possesses this virtue. Most synthetic fibres have the exactly opposite properties of being difficult to stretch but easy to twist, so that fabrics made from them become compact and thin in use or wear. But wool fabrics keep us warm not only bv virtue of this thickness without weight. When we go out-of-doors in winter time we normally go from a dry to a damper atmosphere, and in these circumstances our wool clothes themselves become warm, liberating a large amount of heat which is additional to that given off by our own bodies. ‘‘Central Heating” A man’s suit and overcoat will, in this way, produce as much heat as his body itself evolves in three hours, so that, when clothed in wool, he carries with him a central-heating system which comes into operation just when he needs it most to protect him from a sudden fall in temperature. As fabrics come from the loom they are often thin and sacklike in appearance. It is only in the subsequent "finishing” operations that they are thickened and given the variety of interesting surface textures which fashion demands. Wool is unique in that during these finishing processes it can be made to “felt”—to get thicker and denser—with the spaces between the threads filled up with fibres to produce, for example, a windproof, warm overcoat-

mg. with the original patterns of th# woven threads concealed by a of surface fibre*. Nothing but fibres grown on animals and, first and foremost, wool can be made to felt, and therefore many of the characteristic wool texturescak' not be reproduced in other fibre#. The special felting pronerty of wool fibre appears to be due to such a com. plex structure of its surface that #> far as we can see at present, it j s very unlikely that it could be imitated in a man-made fibre. Their inability to felt is a reawm why many of the fibres put forward as-substitutes for wool—such as those made from milk or peanuts—are rarely used in pure form, but are instead mixed in relatively small proportton, with wool. Another reason for such an admix, ture is that some of the manufactured fibres become weak when they are wet and therefore need to be reinfortyg) with a large proportion of wool if they are to survive the wet process## during manufacture or laundering. ft Secret of Strength Notwithstanding fashion's whims, ws all nowadays expect many of th# clothes we buy to last us well, resist, ing wear and remaining presentaM# till the end of their days. Wool clothes are well known to do this—but why? It is perhaps not because wool flbrm are particularly strong. Although they are sometimes rightly said to be u strong as a steel wire of the same weight, this is nrobably not important Lots of other fibres nre even stronger but wear leas well. Of more importance is that wool is elastic and can adant itself to stress But clothes are only rarely destroyed by a sudden tug which tears them. More often the fibres in garment# ar# bent backwards and forwards day after day until eventually they break, and the short ends are then shed from the fabric, which becomes locally thinner. Many widely used textile fibres art then found to break after between 20 and 100 bends backwards and forwards. Wool is still unbroken afte 20.000 similar bends. Further, clothes must keep their shape, and wool clothes are pre-emta* ent from this point of view. In contrast with many other fibres wool is naturally water-repellant Wtiafc materials as cotton and rayon must first be treated with wax-like tub* stances before they can be us£d at outerwear to be exposed to rain whereas raindrops will run off garments ® made from wool without any snertj treatment provided it is clean sound. . A contrasting property of wool is M reluctance to burn—a safety factor Which is much greater than in thd case of some other materials. ” There are two properties of th# wool fibre which render it unsuitabte for Some clothing purposes: It is liable to felt or shrink when roughly washed, and it is eaten by clothes moths. Wool scientists, however, have not been -idle in these fields, and now have satisfactory processes which wilt overcome these disabilities without tagairing the other good qualities of th* Occasionally It can be claimed for * new fibre that it possesses one or two of the desirable qualities of wool But so far no fibre combines all <3 wools good qualities.