6989 (ISO International Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION MEKAYHAPOAHAH OPrAHV3ALWA HO CTAHAAPTW3ALWWORGANISATION INTERNATIONALE DE NORMALISATION Textile fibres - Determination of length and length distribution of staple fibres (by measurement of single fibres) Fibres textiles -- Détermination de la longueur et de la distribution de longueur des fibres discontinues (par le mesurage de fibres individuelles) First edition - 1981-05-15 UDC 677.017.222 Ref. No. 1SO 6989-1981 (E) SO 6989-1981 dimensional stability tests, classification, test results. Descriptors : textiles, fibres, dimensional measurement, length, physical tests, Price based on 6 pages Copyright International Organization for Standardization Not for Resale Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards institutes (Iso member bodies). The work of developing Inter- national Standards is carried out through iso technical committees. Every member body interested in a subject for which a technical committee has been set up has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the ISO Council. International Standard ISO 6989 was developed by Technical Committee ISO/TC 38, Textiles, and was circulated to the member bodies in November 1979. It has been approved by the member bodies of the following countries : France Australia Portugal Belgium Germany, F.R. Romania Brazil Ghana South Africa, Rep. of Bulgaria India Spain Canada Israel Sweden China Italy Switzerland Cyprus Korea, Rep. of Turkey Czechoslovakia Netherlands United Kingdom Denmark New Zealand USA Norway Egypt, Arab Rep. of Finland Poland The member bodies of the following countries expressed disapproval of the document on technical grounds : Hungary Japan USSR @ International Organization for Standardization, 1981 Printed in Switzerland Copyright International Organization for Standardization ISO 6989-1981 (E) INTERNATIONAL STANDARD Textile fibres -- Determination of length and length fibres) 2 References Introduction 0 This International Standard is intended to replace two existing Iso 139, Textiles - Standard atmospheres for conditioning and testing. International Standards, ISO 270, Textile fibres Determina tion of fibre length by measuring individual fibres, and ISo 1822, Wool -- Determination of fibre length using a single- ISO 1130, Textile fibres - Some methods of sampling for testing. fibre length measuring machine. The determination of fibre length by measuring the length of individual fibres is advocated for the following reasons : 3 Principle Measurement of the individual length of each fibre a) the fibre length is better defined than by measurement of the fibre held in combs; method A : on a straightened fibre on a graduated rule, b) this is a general method, and its range of application is under a light tension applied with the aid of forceps and not limited by the length or diameter of the fibres tested; grease. This method shall be used for reference in cases of dispute, unless strong inherent crimp renders it inap- c) the risk of accidental or systematic errors is less than plicable. withother methods, particularly with collective measurements of the length of a group of fibres. method B : by measuring by use of an opisometer the length of the image of the fibre enlarged by projection on a It should be noted that measurements by this method are made screen. on straightened fibres with the crimp removed, and may give different results from those obtained by other methods of method C : by use of a semi-mechanical device. measurement. In the case of fibres which have inherent crimp, straightening the fibres may also include errors due t