1、BSI Standards PublicationBS ISO 1136:2015Wool Determination ofmean diameter of fibres Airpermeability methodBS ISO 1136:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 1136:2015. The UK participation in its preparation was entrusted to TechnicalCommittee T
2、CI/24, Physical testing of textiles.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Inst
3、itution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 83766 1 ICS 59.060.10 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 March 2015.Amendments
4、/corrigenda issued since publicationDate T e x t a f f e c t e d ISO 2015Wool Determination of mean diameter of fibres Air permeability methodLaine Dtermination du diamtre moyen des fibres MthodepermamtriqueINTERNATIONAL STANDARDISO 1136Second edition 2015-03-01Reference number ISO 1136:2015(E)BS IS
5、O 1136:2015ISO 1136:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or postin
6、g on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso
7、.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 1136:2015ISO 1136:2015(E)Contents PageForeword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Apparatus . 25.1 Forms of apparatus . 25.2 Detailed parts . 26 Conditioning and testing atmosphere 47 Preparat
8、ion of test specimens 47.1 Unopened sliver . 47.1.1 Cleaning . 47.1.2 Number of specimens 47.1.3 Selection of specimens 57.1.4 Specimen mass 57.1.5 Preparation . 57.2 Opened sliver 57.2.1 Cleaning . 57.2.2 Preparation . 57.2.3 Number of specimens 57.2.4 Selection of specimens 57.2.5 Specimen mass 58
9、 Procedure. 68.1 Unopened sliver . 68.2 Opened sliver 69 Expression of results 710 Test report . 7Annex A (informative) Calibration of apparatus 8Annex B (informative) Reproducibility of results 11Annex C (normative) Correction for relative humidity 12Annex D (informative) Special types of wool 13An
10、nex E (informative) Reference slivers for calibration 14Bibliography .15 ISO 2015 All rights reserved iiiBS ISO 1136:2015ISO 1136:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing
11、International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaiso
12、n with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Direct
13、ives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some
14、 of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarat
15、ions received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about
16、 ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT), see the following URL: Foreword Supplementary information .The committee responsible for this document is ISO/TC 38, Textiles, Subcommittee SC 23, Fibres and yarns.This second edition cancels and replaces the first editi
17、on (ISO 1136:1976), which has been technically revised.iv ISO 2015 All rights reservedBS ISO 1136:2015ISO 1136:2015(E)IntroductionWhen a current of air is passed through a uniformly-arranged mass of fibres packed in a chamber with perforated ends, the ratio of air flow to differential pressure is un
18、iquely determined by the total surface area of the fibres, and by various constants. This was predicted from the hydrodynamic equations of Kozeny and others.For fibres of circular or near-circular cross-section and constant density, such as non-medullated wool, the surface area of a given mass of fi
19、bres is proportional to the average fibre diameter. This principle can be utilized to construct apparatus giving an estimate of fibre diameter. Because of its speed and simplicity, the method is particularly suitable for quality control in mill testing laboratories.Since the method is indirect, the
20、apparatus is first calibrated from wools of known fibre diameter. For this purpose, eight reference slivers have been provided (see Annex E).It has been shown that the estimate of fibre diameter actually given by the permeability method is d (1+c2), where d is the average fibre diameter (length bias
21、ed) measured by the projection microscope, and c is the fractional coefficient of variation. Since c normally lies within comparatively small limits for unblended slivers, it is usual, however, to calibrate the apparatus directly in terms of d.The method requires that the fibres be reasonably clean
22、and dispersed in a uniform open state, such as card slivers or combed slivers. It is thus unsuitable for raw wool unless first scoured and carded. Some types of wool need special calibrations as described in Annex D.The preparation of test specimens for measurement is identical with that used for ca
23、libration specimens.This second edition to ISO 1136 is based on the test method IWTO-6-98, drawn up by the International Wool Textile Organization (IWTO). ISO 2015 All rights reserved vBS ISO 1136:2015BS ISO 1136:2015Wool Determination of mean diameter of fibres Air permeability method1 ScopeThis In
24、ternational Standard specifies a method for the determination of the mean diameter of wool fibres, using an apparatus which passes a current of air through a bundle of fibres.This International Standard is applicable to clean, unmedullated wool fibres dispersed in a uniform, open state. It provides
25、a method particularly suitable for combed slivers. The dichloromethane extractable matter content of the specimen must not exceed 1,0 %. It is applicable to oil-combed slivers after cleaning with an organic solvent.The method described in this International Standard is less accurate for lambswool an
26、d for wool which is appreciably medullated (see Annex D) and heavily dyed wool.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated
27、references, the latest edition of the referenced document (including any amendments) applies.ISO 139, Textiles Standard atmospheres for conditioning and testing3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1laboratory sampleconditioned sample o
28、f fibres, representative of the bulk, from which the test specimens are weighed outNote 1 to entry: In many cases, the laboratory sample will consist of one or more short lengths of sliver.3.2test specimenweighed amount of fibre which is packed into the constant volume chamber4 PrincipleA specified
29、mass of fibres to be tested is compressed to a constant volume in a cylindrical chamber with perforated ends to which a flowmeter and a manometer are connected.The fibres are packed in such a way that they lie predominantly at right angles to the long axis of the chamber. A regulated current of air
30、is then passed through the compressed fibres and the average fibre diameter read off from a scale on the manometer or the flowmeter.INTERNATIONAL STANDARD ISO 1136:2015(E) ISO 2015 All rights reserved 1BS ISO 1136:2015ISO 1136:2015(E)5 Apparatus5.1 Forms of apparatusTwo alternative forms of apparatu
31、s are described: “constant flow” and “constant pressure”. Both forms of apparatus have the same arrangement of parts, as illustrated in Figure 1.The constant flow apparatus utilizes a specimen mass of 1,5 g; the flowmeter is adjusted to a fixed value and the fibre diameter is read off from the manom
32、eter scale. This scale is not linear since the successive intervals, corresponding to 1 m, decrease with the diameter.The constant pressure apparatus utilizes a specimen mass of 2,5 g; the manometer is adjusted to a fixed pressure and the fibre diameter is read off from the flowmeter. The constant p
33、ressure apparatus gives a nearly linear scale in micrometres. Since less accuracy in weighing the specimen is required, this method has some advantages for mill use.5.2 Detailed partsThe apparatus consists of the following parts arranged as shown in Figure 1.ABCEDPQRTo pumpFibresKeyA constant volume
34、 chamberB air valveC manometerD reservoirE flowmeterP, Q, R reference marksFigure 1 General arrangement of apparatus5.2.1 Air valve (B), giving sufficiently fine control of the air supply, such that the lever of the flowmeter or manometer can be quickly adjusted to the working value.5.2.2 Suction pu
35、mp, of a type providing a smooth output of at least 30 l/min at 200 mmH2O with minimal fluctuation of the float of the flowmeter. A filter to trap any loose fibres may be inserted between the pump and the air valve (B).NOTE 1 mmH2O=9 806 65 Pa=9 806 65 N/m22 ISO 2015 All rights reservedBS ISO 1136:2
36、015ISO 1136:2015(E)5.2.3 Constant volume chamber (A), of brass, hardened steel, or any other suitable metal, comprising the three following parts: the base into which the fibres are packed, the plunger which compresses the fibres, and the screw cap which clamps the plunger to the base.The finish sha
37、ll be smooth so that the plunger slides easily into the base without trapping fibres. Suggested dimensions of the constituent elements of the chamber are given in Figure 2.Figure 2 Suggested dimensions of constant volume chamber (A)Important dimensions are 22,325,225,2542,5 and 38,1 mm.5.2.4 Manomet
38、er (C), made of glass tubing of internal diameter at least 5 mm to reduce surface tension effects.In both cases, a small amount of dye may be added to the manometer fluid, and where this consists of distilled water, a small trace of chromic acid should be added to give a clear meniscus. A millimetre
39、 scale is fixed behind the open limb as described in A.3.1.5.2.5 Reservoir (D) of the fluid manometer (5.2.4), having the characteristics specified in the following table, and mounted at a sufficient height to give a clear working distance PQ of 350 mm in the open limb of the manometer.Table 1 Manom
40、eter and flowmeter characteristicsCharacteristic Constant flow Constant pressureMinimum diameter of reser-voir150 mm 60 mmType of manometer fluidn-Propyl alcoholDistilled waterWorking range of flowmeter10 l/min to 20 l/min5 l/min to 25 l/min ISO 2015 All rights reserved 3BS ISO 1136:2015ISO 1136:201
41、5(E)5.2.6 Flowmeter (E), having the characteristics indicated in Table 1.5.2.7 Rubber tube, connecting the manometer reservoir (D) to the chamber (A), consisting of pressure tubing of small internal diameter to avoid constriction at the bends.5.2.8 Rubber or plastic tube from the chamber (A) to the
42、flowmeter (E), of internal diameter not less than 6 mm. The tube shall be as short as possible and shall not be twisted or kinked between calibration of the apparatus and its subsequent use.5.2.9 Balance, capable of weighing the specimen to an accuracy of 2 mg for the constant flow method and of 4 m
43、g for the constant pressure method.6 Conditioning and testing atmosphere6.1 The test specimens shall be dried sufficiently and brought to equilibrium and tested in one of the standard atmospheres for testing specified in ISO 139.NOTE The laboratory sample can be dried in an oven with forced draft ci
44、rculation or a rapid dryer at between 50 C to 107 C. The time required needs to be determined for the specific laboratory situation.Each laboratory is to carry out investigations on the rate of equilibration, for its particular conditioning system, of wool samples prepared in its specific equipment
45、so that the appropriate conditioning time can be established.6.2 The tested specimen shall be weighed in the standard atmospheres at the level of accuracy specified in the method.6.3 If tests are not carried out in the standard atmosphere for testing, the laboratory sample shall be conditioned to eq
46、uilibrium near the apparatus and the relative humidity of the atmosphere at the time of test noted. The final results shall be corrected by the factors given in Annex C.NOTE A source of error might occur if the moisture of the specimen changes during test. This could happen if the laboratory sample
47、is allowed insufficient time to attain moisture equilibrium with the testing atmosphere. The minimum time required to ensure conditioning to equilibrium of a length of sliver in an opened-out state in a well-ventilated room is about 60 min.7 Preparation of test specimens7.1 Unopened sliver7.1.1 Clea
48、ningIn general, the laboratory sample shall have a mass of about 8 g and shall first be degreased by rinsing well in two baths each of about 200 ml of petroleum ether before conditioning.7.1.2 Number of specimensUnless otherwise specified, test a minimum of two specimens for fibre diameter below 30
49、m and a minimum of three specimens for fibre diameter above 30 m.4 ISO 2015 All rights reservedBS ISO 1136:2015ISO 1136:2015(E)7.1.3 Selection of specimensThe specimens shall be taken from different places in the laboratory sample. In the case of balls of sliver, the laboratory sample shall be made up of pieces of sliver from both inside and outside the ball.7.1.4 Specimen massFor the constant flow method, the specimen mass shall be 1,5 g 0,002 g. For the constant pressure method, the specimen mass shall be 2,5 g
