7211/3 nternational Standard (ISO INTE RNATIONAL ORGANIZATION FOR STANDARDIZATION MEKAYHAPOAHAA OPrAHM3AUMA nO CTAHAAPTW3AUMW-ORGANISATION INTE RNATIONALE DE NORMALISATION Textiles - Woven fabrics Construction - Methods of analysis - Part 3: Determination of crimp of yarn in fabric Textiles -- Tissus -- Construction-- Methodes d'analyse -- Partie 3: Détermination de I'embuvage d'un fil dans un tissu First edition - 1984-03-15 ：07211/3-1984(E) UDC 677.064 : 677.014.886 Ref. No.1SO 7211/3-1984 (E) Descriptors:textiles,wovenfabrics,tests,determination,crimp,yarns,testspecimens,testequipment,testresults. Price based on 3 pages No reproduction or networking permited without license from IHS Not for Resale Foreword ISo (the International Organization for Standardization) is a worldwide federation of national standards bodies (iso member bodies). The work of developing International Standards is carried out through iso technical committees. Every member body interested in a subject forwhich a technical committee has been authorized has the right to be represented on that committee. Internationat 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 7211/3 was developed by Technical Committee ISO/TC 38, Textiles, and was circulated to the member bodies in November 1982. It has been approved by the member bodies of the following countries: Australia India Portugal Belgium Iran Romania Brazil Iraq South Africa, Rep. of Bulgaria Israel Spain Canada Italy Sweden China Jamaica Tanzania Czechoslovakia Japan Thailand Egypt, Arab Rep. of Korea, Rep. of Turkey Finland Mexico United Kingdom Germany, F.R. Netherlands USA Ghana New Zealand USSR Hungary Poland Venezuela Thememberbodyofthefollowingcountryexpresseddisapprovalofthedocumenton technical grounds : France International Organization for Standardization, 1984 Printed in Switzerland Copyright International Organization for Standardization No reproduction or networking permitted without license from IHS Not for Resale ISO 7211/3-1984 (E) INTERNATIONALSTANDARD Textiles - Woven fabrics - Construction - Methods of analysis - Part 3: Determination of crimp of yarn in fabric 0 Introduction 4 Principle The interlacing of threads in a fabric imposes a waviness or Threads are removed from a strip of fabric of known length, crimp on bothwarpand weft yarns.Hence,the distancebe- straightened by a tension which is varied according to the tween the ends of a warp thread, for instance, as it lies in a nature and linear density of the yarn and measured in the piece of fabric, is less than the length of the straightened straightened state. The difference between the straightened thread, and the difference between these two lengths is used in length of the thread and the distance between the ends while in themeasurementof crimp. the fabric is expressed as a percentage of the latter. In this technique it is necessary to apply a tension to straighten the crimped thread. Idealy, this tension would be one which 5 Apparatus removes all crimp without extending the thread, but this will rarelybepossible.Consequently,atableoftensionshasbeen 5.1 Thread straightening and measuring device, horizon- included (see the annex) as a guide with the aim of striking a tal or vertical and complying with the following requirements : balance between some inevitable extension and the incomplete removal of crimp; any residual crimp is then ignored. a) there shall be two yarn grips, each of which closes at its rear end first and when closed has parallel gripping- When a figured fabric is under examination, it will be necessary surfaces; to ensure that threads for testing are taken from a complete repeat of the pattern. b) it shall be possible to alter the distance between the