1、BRITISH STANDARD BS ISO 6989:1981 Textiles fibres Determination of length and length distribution of staple fibres (by measurement of single fibres) ICS 59.060.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS ISO 6989:1981 This British Standard, having been prepared under
2、the direction of the Materials and Chemicals Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 20 May 2002 BSI 20 May 2002 ISBN 0 580 39663 0 National foreword This British Standard reproduces verbatim ISO 6989:1981 and implemen
3、ts it as the UK national standard. It supersedes BS 6176:1981 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee TCI/24, Physical testing of textiles, which has the responsibility to: A list of organizations represented on this committee can be obtained
4、on request to its secretary. Cross-references The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facili
5、ty of the BSI Standards Electronic Catalogue. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligati
6、ons. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of p
7、ages This document comprises a front cover, an inside front cover, ISO title page, the ISO foreword page, pages 1 to 6, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. D
8、ate CommentsInternational Standard INTERNATIONAL ORGANIZATION FOR STANDARDIZATION*MEWYHAPOAHAFI OPrAHM3AWlR fl0 CTAHAPTM3ALWl.ORGANISATlON INTERNATIONALE DE NORMALISATION Textile fibres - Determination of length and length distribution of staple fibres (by measurement of Single fibres) Fibres textil
9、es - LMermination de Ia longueur et de Ia distribution de longueur des fibres discon tinues (par Ie mesurage de fibres individuelles) First edition - 1981-05-15 lJ DC 677.017222 Ref. No. ISO 69894981 (EI Descriptors : textiles, fibres, dimensional measurement, length, physical tests, dimensional sta
10、bility tests, classification, test results. ecirP desab no 6 segap Foreword ISO (the International Organization for Standardization) is a worldwide federation of national Standards institutes (ISO member bedies). The work of developing Inter- national Standards is carried out through ISO technical c
11、ommittees. 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 adopt
12、ed 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. l
13、t has been approved by the member bodies of the following countries : Australia Belgium Brazil Bulgaria Canada China Cyprus Czechoslovakia Denmark Egypt, Arab Rep. of Finland The member bodies of on technical grounds : the fol lowing countries expressed disapproval of the docu France Germany, F. R.
14、Ghana India Israel Italy Korea, Rep. of Netherlands New Zealand Norway Poland Hungary Japan USSR 0 lanoitanretnI noitazinagrO rof ,noitazidradnatS 1891 Portugal Romania South Africa, Rep. of Spain Sweden Switzerland Turkey United Kingdom USA detnirP ni dnalreztiwS INTERNATIONAL STANDARD ISO 69894981
15、 (E) Textile fibres - Determination of length and length distribution of staple fibres (by measurement of Single fibres) 0 Introduction This International Standard is intended to replace two existing International Standards, ISO 270, Textile fibres - Determina- tion of fibre length by measuring indi
16、vidual fibres, and ISO 1822, Wool - Determination of fibre length using a single- fibre length measuring machine. The determination of fibre length by measuring the length of individual fibres is advocated for the following reasons : a) the fibre length is better defined than by measurement of the f
17、ibre held in combs; b) this is a general method, and its range of application is . not limited by the length or diameter of the fibres tested; c) the risk of accidental or systematic errors is less than with other methods, particularly with collective measurements of the length of a group of fibres.
18、 lt should be noted that measurements by this method are made on straightened fibres with the crimp removed, and may give different results from those obtained by other methods of measurement. In the case of fibres which have inherent crimp, straightening the fibres may also include errors due to st
19、ret- ching. Nevertheless, other methods (for example, the comb Sorter) are quicker for some fibres (for example, cotton or other short fibres), and for this reason may be preferred, for routine tests, to the more exact method of measuring individual fibre lengths. ISO 2646, Wool - Measurement of the
20、 length of fibres pro- cessed on the worsted System, using a fibre diagram machine, may be used for the determination of the distribution of the length of fibres by measurement carried out on specimens of sliver processed on the worsted System. 1 Scope and field of application This International Sta
21、ndard specifies - three methods for determination of the length of staple fibres by measuring individual fibres; - different methods of expressing the length distribution from values obtained by measurement of individual fibres. lt applies to all discontinuous textile fibres, except those in which s
22、trong inherent crimp would render the procedure inap- plicable. lt does not apply to fibrous bundles of bast fibres. 2 References ISO 139, TextIes - Standard atmospheres for conditioning and tes ting. ISO 1130, TextJe fibres - Some methods of sampling for tes ting. 3 Principle Measurement of the ind
23、ividual length of each fibre - method A : on a straightened fibre on a graduated rule, under a light tension applied with the aid of forceps and grease. This method shall be used for reference in cases of dispute, unless strong inherent crimp renders it inap- plicable. - method B : by measuring by u
24、se of an opisometer the length of the image of the fibre enlarged by projection on a Screen. - method C : by use of a semi-mechanical device. Expression of the length distribution of fibres from the values of fibre length, classing the fibres into groups of length. 4 Apparatus and materials 4.1 Meth
25、od A (Reference method) 4.1 .l Polished glass plate, with a millimetre scale engraved or photographed on it. 4.1.2 Pointed forceps. 4.1.3 White Petroleum jelly or liquid Paraffin. 4.2 Method B 4.2.1 Projector and Screen, with means for mounting fibres on the projector slide. 4.2.2 Opisometer and cal
26、ibration slide, or other means for determining projector magnification. 4.2.3 White Petroleum jelly or liquid Paraffin. ISO 69894981 (E) 4.3 Method C sion at its two extremities. Measure the length of the fibre along the scale. Repeat the Operation for each fibre to be tested. 4.3.1 Apparatus for ca
27、rrying out semi-automatic measure- ment of the fibre length under controlled tension, classification of fibre length in groups or classes in intervals of determined length, and registering the number of fibres in each of these groups. 7.1.2 Method B. image of a fibre Measurement of the length of the
28、 Smear the slide (4.2.2) with a thin film of the white Petroleum jelly or liquid Paraffin (4.2.31, applied with a Paper tissue. Lay a convenient number of fibres on the oiled slide; bend the fibres if they are longer that the projection field. Place a clean cover- glass on top of the fibres and hold
29、 the assembly firmly together with a small piece of adhesive tape. A convenient apparatus for use in this method is described in the annex. 4.3.2 Pointed forceps. 4.3.3 Short graduated rule, having two marks, 5 mm apart. For fibres less than 90 mm in length, use a magnification of 10 x . For longer
30、fibres, a magnification of 5 x is sufficient. 5 Atmospheres for conditioning and testing Determine the magnification of the equipment by measuring the image length of the calibration slide with the opisometer (4.2.2). Measure the length of the images of the fibres in turn with the opisometer. Condit
31、ion the fibres and keep them in the Standard atmosphere for testing, as defined in ISO 139, i.e. an atmosphere having a relative humidity of (65 + 2) % and a temperature of 20 1,96s in absolute value : A (mm) = + - dq Cni is the total number of fibres in all classes; 1,96 cv - relative value : A % =
32、 + - fi CIZili is the sum of the products Yli X li for all classes. This latter value coincides with the percentage frequency by mass only if fibres of different lengths have the same mass per unit length. This is not always the case, especially for natura1 fibres. 8.2.4 Expression of the frequency
33、distribution If a length distribution graph is required, express it 8.2 Characteristic distri bution values - by a frequency histogram representing the percentage of the number of fibres in each length interval employed, expressed as a function of the length; 8.2.1 Lengths The following characterist
34、ic distribution values are commonly calculated (other quantities may also be calculated for par- ticular purposes) : - by a cumulative frequency diagram indicating the percentage as a function of fibres greater than a given length, expressed as a function of the length. a) the modal length (the cent
35、ral length of the most numerous class); 9 Test report The test report shall include the following particulars. b) the mean length of the individual fibres : DZili L=- C?i 9.1 The number of fibres measured : - the mean length of individual fibres L; c) the length-biased mean length of fibres in a sli
36、ver, roving or yarn section : L Ihil =- Z?lili Express these lengths in millimetres. - the coefficient of Variation; - the frequency histogram or the cumulative frequency diagram, if a distribution graph is required; - the number of fibres, if not zero, in any classes ex- cluded from the calculation
37、 of mean length and coefficient of Variation. 3 ISO 69894981 (EI 9.2 If required : - the percentage by number of the fibres in each class; 9.3 Reference to this International Standard and the method used, including the type of apparatus if method C was employed, - the class intervals used; 9.4 All o
38、perations not specified in this International Stan- dard, and all incidents likely to have had an effect on the - the modal class length; results. - the length-biased mean length of the fibres; - the confidence limits (normally the 95 % confidence limits). ISO 6989-1981 (E) Annex “Wira” fibre length
39、 machinel) (Forms part of the Standard. 1 A.l Characteristics The principal features of this machine are the means for automatically measuring fibre length under controlled tension, means for automatically classifying the fibre lengths into 5 mm groups and means for registering the number of fibres
40、in each of these groups. Figures 1 and 2 illustrate the essential feafures.2) ,1- A.2 Calibration Switch on the machine, depress the operating key as far as it will go, and check that the fibre detector wire (11) falls into the space between the anvil (3) and the fibre support (121, and that its end
41、 just dips into the mercury, thus actuating the stop- motion and stopping the traverse screw (9). If the detector wire does not fall into its correct place, adjust its lateral Position by carefully bending it with a dissecting needle at a Point near its fixed end. Check also that the fibre detector
42、wire lies parallel to the pressure plate (2) when in the raised Position and about 0,5 mm below it. If it does not do so, adjust the vertical posi- tions by bending it with a dissecting needle near its fixed end. By means of the forceps, select a fibre and measure its length in the way specified in
43、7.1, noting whether the screw (9) is stopped immediately the fibre end Slips clear of the anvil. If it is not, adjust the level of the mercury until the screw is being stopped satisfactorily on release of a fibre. A.3 Measurement A.3.1 Position the fibres to be measured on a Velvet board at a height
44、 such that fibres may be gripped and drawn over the approach pad and through the fibre guide (10). 1) The information results may be used given on this machine is not intended to favour its use or to give preference to this apparatus. Other apparatus giving equivalent 2) Full details of the Operatio
45、n of S.L. Anderson and R .C. Palmer. the machine are given in J. Test. hst., 1953, 44,3, T95 : “A machine for measuring the length of Single fibres”, by A.3.2 Reset all the counters to zero by rotating the counter reset wheel in a clockwise direction and rotating the counters towards the front of th
46、e machine until they are all stopped. The counter reset wheel is then rotated as far as it will go in an anti- clockwise direction, thus freeing the counters. A.3.3 Measure and record the length of each fibre in the Sample in the following way : Grip the end of a fibre with the pointed forceps (6) a
47、nd with the operating key in the up Position pull the fibre over the approach pad and introduce it into the fibre guide (10). Depress the operating key with the left forefinger and move the forceps to the right, parallel with the traverse screw (9), until only a short length of the fibre remains to
48、be drawn through the guide. The forceps shall not tauch the traverse screw during this Operation. Push the Points of the forceps holding the fibre gently forward until they rest in the angle between the traverse screw and the forceps guide bar (8). They will then fall into the nearest approaching gr
49、oove of the traverse screw and be carried sideways at a constant Speed, drawing the fibre between pressure plate (2) and anvil (3) and ultimately stopping the traverse screw. The operating key is still held in the down posi- tion during this movement; the forceps shall be held at about 90 to the screw whilst being traversed, and shall not beinclined enough to make them tauch the counter keys in passing. Then move the forceps upwards, quickly raising the counting key, which lies immediately above, and thus recording the fibre length. Very short fibres, i.e. less than 5 mm l
