Agave Fibres. I. Morphology, Histology, Length and fineness; Grading Problems

Abstract

The paper is in the nature of a progress report on the work done on agaves as fibre producing plants at Amani during the last few years. Agave fibres are of 3 fairly well-defined types: - Mechanical, most strongly developed round the periphery of the leaf; these fibres are of great importance commercially; owing to their shape they seldom divide during manufacture and on their fineness depends the fineness of the sample. Ribbon fibres occur always in association with the conducting tissues though they are present in various sizes in all parts of the leaf except the extreme periphery; they form the longest fibres in the leaf and are important in that they split longitudinally, unlike the mechanical fibres, and therefore their original size does not influence fineness. Xylem fibres are of no commercial importance, being broken up and lost during decortication. Short leaves, whether caused by early cutting or environment, do not produce a markedly finer fibre than long leaves. Fineness of fibre is varietal, in which respect A. amaniensis and A. cantala are much superior to A. sisalana. A. amaniensis possesses a larger amount of short fibres than A. sisalana, but this is offset by the greater length of its leaves. The proportion of mechanical to ribbon fibre in A. amaniensis is twice as great as in A. sisalana. This fact is of technical importance, giving the fibres a different intrinsic make-up and probably affecting spinning behaviour. Methods of mechanical grading to replace the present grading by eye are thoroughly discussed and the defects of the present system pointed out. Nevertheless, expensive grading schemes cannot be put into operation until the consumer gives some indication of the type of fibre required, and so far, this has not been forthcoming.