NOT A SUBSTITUTE

Wairarapa Times-Age, 8 July 1939, Page 11

NOT A SUBSTITUTE

STAPLE FIBRE AND WOOL FRANK GERMAN STATEMENT. DEFECTS NOT OVERCOME. The Imperial Economic Committee has recently issued a translation _ (republished in the- I.W.S. News, the journal of the International Wool Secretariat' of extracts from Klepzig’s Textil Zeitschrifl, of January 4. 1939. which provides a frank and unbiased comparison between wool and the qualities of flic most recent "W" or wool types of staple fibre. We are reminded first that the presence today in staple fibre of tensile strength equal to or superior to that of dry wool is of little significance in reproducing the characteristics of wool. High tensile strength is not a peculiar virtue of wool. It is the elasticity of the wool fibre and the influence of this both on processing and the characteristics of wool fabrics which are unique, and this is due not only to the chemical and physical structure of the fibre, but to the presence of crimp. Structural elongation of the fibre made possible by crimp precedes the elongation of the fibre itself. In the case of fibres lacking crimp, the fibre itself is affected by any elongation and in manufacture a certain proportion of such elongation is permanent and irreversible. It is maintained that up to the present no attempt to reproduce the true qualities of wool crimp, from a manufacturing standpoint, has succeeded.

UNIQUE FELTING PROPERTIES. Again the scale formation of the wool fibre confers its valuable felting properties. Staple fibre, apart from casein fibres (which have other serious technical faults) shows as little felting properties as other fibres of vegetable origin. But, as . this article points out. the felting properties of wool are not dependent on their surface structure alone.- There is. in addition, the "almost ideal elasticity of wool in a wet state.” It is further admitted that, while the strength of cellulose staple fibres is now satisfactory, an improvement in resistance to creasing and in bending resistance is still necessary. SWELLING OF STAPLE FIBRE. Another defect which still causes difficulty is the marked swelling of staple fibre in water. Attempts to counteract this have led to the inclusion of artificial resins in the fibre, but these do not lead to any increase in the wet strength of the fibre. The development of a completely waterrepellant fibre by this means would be of questionable value since such a fibre would not absorb perspiration and might be far from pleasant to wear. The problem of achieving dyes with the colour fastness of wool has been attempted by including nitrogenous substances in the spinning solution or by depositing nitrogen on the surface of the fibres. For these measures to be successful it is necessary to obtain nitrogen with the cellulose molecule itself. Even so, for fast shades, dyers are recommended to dye each material separately. The author of the article concludes with the reminder that seen in its true light, staple fibre is an addition to the list of textile fibres which gives its best results when spun and manufactured in its pure state. But the same standards of performance have been asked of it as of natural fibres when, as through the pressure of events, it has been required to supplement supplies of other textile materials in branches of consumption for which it is not suitable. LOOKING FORWARD. The International Wool Secretariat has never questioned the virtues of staple fibre as a now and useful fibre in its own right, but that in no way admits of claims for it as a substitute for’wool. That a similar view is'coming to be held in Germany and the evidence of this in the greater consumption of wool by Germany in 1938, gives ground for belief that, with a return of international confidence and the lowering of trade barriers, we may look forward to a revival in demand for wool, even in those countries in which most strenuous efforts have been made to effect substitution fob wool by staple fibre. Towards that goal every interest should direct its efforts.