1、BSI Standards PublicationBS ISO 5636-4:2013Paper and board Determination of airpermeance (medium range)Part 4: Sheffield methodBS ISO 5636-4:2013 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 5636-4:2013. Itsupersedes BS ISO 5636-4:2005 which is withdrawn.The
2、 UK participation in its preparation was entrusted to TechnicalCommittee PAI/11, Methods of test for paper, board and pulps.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a c
3、ontract. Users are responsible for its correctapplication. The British Standards Institution 2013. Published by BSI StandardsLimited 2013ISBN 978 0 580 66118 1ICS 85.060Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the autho
4、rity of theStandards Policy and Strategy Committee on 31 October 2013.Amendments issued since publicationDate Text affectedBS ISO 5636-4:2013 ISO 2013Paper and board Determination of air permeance (medium range) Part 4: Sheffield methodPapier et carton Dtermination de la permance lair (valeur moyenn
5、e) Partie 4: Mthode SheffieldINTERNATIONAL STANDARDISO5636-4Third edition2013-11-01Reference numberISO 5636-4:2013(E)BS ISO 5636-4:2013ISO 5636-4:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no part of this publication ma
6、y be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting 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
7、 requester.ISO copyright officeCase postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 5636-4:2013ISO 5636-4:2013(E) ISO 2013 All rights reserved iiiContents PageForeword iv1 Scope . 12 Normative references 13 T
8、erms and definitions . 14 Principle 15 Apparatus . 26 Sampling 37 Conditioning 38 Preparation of test pieces . 39 Calibration 49.1 Variable-area flow-measuring device 49.2 Electronic flow-measuring device 410 Procedure. 411 Expression of results 411.1 Calculation of air permeance 411.2 Reporting the
9、 results . 511.3 Standard deviation and coefficient of variation . 512 Test report . 5Annex A (normative) Calibration of flowmeters 6Annex B (informative) Conversion of Sheffield units (SU) to SI units 10Annex C (informative) Precision data .11Bibliography .13BS ISO 5636-4:2013ISO 5636-4:2013(E)Fore
10、wordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a techni
11、cal committee has been established 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. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of e
12、lectrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents should be noted. This document wa
13、s 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 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 pate
14、nt 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 declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not c
15、onstitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe
16、 committee responsible for this document is ISO/TC 6, Paper, board and pulps, Subcommittee SC 2, Test methods and quality specifications for paper and board.This third edition cancels and replaces the second edition (ISO 5636-4:2005), which has been technically revised. In this third edition mainly
17、editorial changes have been made and also precision data has been added as informative Annex C.ISO 5636 consists of the following parts, under the general title Paper and board Determination of air permeance (medium range): Part 3: Bendtsen method Part 4: Sheffield method Part 5: Gurley method Part
18、6: Oken methodNOTE 1 Part 1: General method will be withdrawn after the third editions of Parts 3, 4 and 5 have been published, as it was considered redundant.NOTE 2 Part 2: Schopper method was withdrawn in 2006 as it was considered obsolete.NOTE 3 Part 6: Oken method is being prepared.iv ISO 2013 A
19、ll rights reservedBS ISO 5636-4:2013INTERNATIONAL STANDARD ISO 5636-4:2013(E)Paper and board Determination of air permeance (medium range) Part 4: Sheffield method1 ScopeThis part of ISO 5636 specifies the Sheffield method for determining the air permeance of paper and board using the Sheffield appa
20、ratus.It is applicable to papers and boards which have air permeances between 0,02 m/(Pas) and 25 m/(Pas) when tested with the Sheffield apparatus.It is unsuitable for rough-surfaced materials, which cannot be securely clamped to avoid leakage.2 Normative referencesThe following documents, in whole
21、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 references, the latest edition of the referenced document (including any amendments) applies.ISO 186, Paper and board Sampling to deter
22、mine average qualityISO 187, Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samples3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1air permeancemean air flo
23、w rate through unit area under unit pressure difference in unit time, under specified conditionsNote 1 to entry: Air permeance is expressed in micrometres per pascal second 1 ml/(m2Pas) = 1 m/(Pas).Note 2 to entry: This property is called air permeance, and not air permeability, because it is report
24、ed as a sheet property and is not standardized with respect to thickness to give a material property per unit thickness.Note 3 to entry: The Sheffield unit is not defined, since it has been shown that the scale units (Sheffield units) on different types of Sheffield instruments can correspond to dif
25、ferent air flows, and there is no precise physical definition. This part of ISO 5636 requires that the flowmeters be calibrated to give a flow rate in millilitres per minute.4 PrincipleA test piece is clamped between two rubber orifice plates of known dimensions. The absolute air pressure on one sid
26、e of the test piece is equivalent to atmospheric pressure and the difference in pressure between the two sides of the piece is maintained at a small, substantially constant, value. The air flow rate through the test area is determined and the air permeance is calculated. ISO 2013 All rights reserved
27、 1BS ISO 5636-4:2013ISO 5636-4:2013(E)5 ApparatusThe Sheffield apparatus, see Figure 1 for an example of one type of instrument, shall consist of an air supply (see 5.1), an air-pressure regulating device (see 5.2), a pressure manometer (see 5.3), an air-flow-measuring device (see 5.4) and a test as
28、sembly (see 5.5) which houses a measuring head in which the test piece can be securely clamped.1234 57896Key1 air supply2 pressure regulator3 air-flow-measuring device4 flow impedance5 shut-off valve6 measurement air7 clamping air pressure8 orifice plates9 test pieceFigure 1 Principles of operation
29、of one type of apparatus5.1 Air supply, free from water, oil and other contaminants, at a pressure of 420 kPa to 950 kPa. A small compressor using laboratory air is preferred to external compressed air.5.2 Air-pressure regulating device, to reduce the pressure to the nominal pressure at the measurin
30、g head of 10,3 kPa (variable-area flow-measuring devices, see 5.4.1) or 9,85 kPa (electronic flow-measuring devices, see 5.4.2).5.3 Pressure manometer, with a suitable range to enable the air pressure at the measuring head to be set to the specified pressure within 2 % of the nominal value.5.4 Air-f
31、low-measuring device, of either a variable-area (5.4.1) or an electronic type (5.4.2), for measuring the air flow rate to the measuring head. The air flow rate shall be measurable to an accuracy of 5 % of the measured value.5.4.1 Variable-area flow-measuring device, consisting of three variable-area
32、 flowmeters each having a tapered glass column containing a metering float suspended by the air flow in the column. The three columns shall be chosen with dimensions such that they enable measurements to be made on a continuous scale of flow rate from 10 ml/min to 3 000 ml/min, with some overlap of
33、scales between columns. Each 2 ISO 2013 All rights reservedBS ISO 5636-4:2013ISO 5636-4:2013(E)column shall be provided with a means of adjusting the flow rate (float-position knob) and a means of span calibration (calibration knob). This type of instrument shall operate at a supply pressure of 10,3
34、 kPa.At air flow rates greater than 1 200 ml/min, the pressure drop in the Sheffield system is substantial. To ensure reproducibility of results, it is necessary that the tubing used to connect the flowmeter to the measuring head be carefully controlled with a length of (1,50 0,01) m and an internal
35、 diameter of (6,25 0,25) mm. For the same reason, openings in valves and other fittings on the instrument shall not be changed from those provided by the instrument manufacturer.5.4.2 Electronic flow-measuring device, for measuring the air flow to the measuring head. The inlet pressure to the measur
36、ement device shall be controlled at 9,85 kPa.NOTE The 9,85 kPa pressure is the typical pressure measured downstream of variable-area flow tubes that have been calibrated using the air bleeds (zero and span-adjustment) to the atmosphere.5.5 Test piece clamping device (test assembly), incorporating a
37、detachable measuring head with a set of rubber orifice plates to provide a test area of 283,5 mm2(19 mm diameter), constructed so that a test piece can be clamped between the orifice plates.NOTE Additional sets of orifice plates may be available for the following four optional test areas: 71 mm2(9,5
38、 mm diameter); 1 135 mm2(38 mm diameter); 2 550 mm2(57 mm diameter); 4 540 mm2(76 mm diameter);but the use of these test areas is not in accordance with this part of ISO 5636. Doubling the test area does not necessarily double the air flow, since the specific design of the instrument means that the
39、pressure difference is affected by the test area.5.6 Flat non-porous plate, of approximate dimensions 100 mm x 100 mm, which can be clamped between the rubber orifice plates to check the zero reading.5.7 Calibration plate device, to enable the test assembly to be connected to an external calibration
40、 system (see Clause 9 and Annex A).6 SamplingIf the mean quality of a lot is to be determined, sampling shall be in accordance with ISO 186. If the tests are made on another type of sample, make sure that the test pieces taken are representative of the sample received.7 ConditioningCondition the sam
41、ple in accordance with ISO 187.8 Preparation of test piecesPrepare the test pieces in the same atmospheric conditions as were used to condition the sample.Cut not less than 10 test pieces, each at least 15 mm larger in both dimensions than the diameter of the circular orifice of the rubber plate to
42、be used, and identify their two sides, for example side 1 and side 2. The test area shall be free from folds, wrinkles, holes, watermarks or defects not inherent in the sample. Do not handle the part of the test piece which will become the test area. ISO 2013 All rights reserved 3BS ISO 5636-4:2013I
43、SO 5636-4:2013(E)If the air permeances measured on the two sides differ significantly and if this difference is required to be shown in the test report, 10 tests are required for each side.9 Calibration9.1 Variable-area flow-measuring deviceCalibrate the instrument against an external flow-measuring
44、 device as described in A.1, and prepare a calibration graph or chart as described in A.2.Calibrate the instrument sufficiently frequently to ensure that the reading does not deviate at any time by more than 5 % from the true value.9.2 Electronic flow-measuring deviceCarry out the internal adjustmen
45、t of the flowmeter according to the manufacturers instructions. Check the calibration of the instrument against an external flow-measuring device as described in A.1.10 ProcedureCarry out the test in the same atmospheric conditions as used for the conditioning and preparation of test pieces.Tests sh
46、all be performed according to instructions of the manufacturer.Test a minimum of 10 test pieces, five with side 1 up and five with side 1 down.Check that the air pressure to the measuring head is correct (see 5.4.1 or 5.4.2). Check that the air flow reading obtained with the non-porous plate (see 5.
47、6) clamped in the measurement gap is zero.Apply the internal adjustment procedure described in the instructions of the manufacturer frequently if the instrument is being used for long periods (at least twice in an 8 h day), and whenever the air supply to the instrument is interrupted.NOTE For daily
48、use, it is preferable to leave the air supply on in order to minimize drift in the regulator.Place a test piece in the measuring gap and measure the air flow rate in accordance with the instructions of the manufacturer. Record the result. Repeat for the remaining test pieces.All papers are hygrosens
49、itive to some degree, and readings should be taken at the initial stabilization point to avoid any possible effect of incoming air adding moisture to, or extracting moisture from, the test piece.11 Expression of results11.1 Calculation of air permeanceIf the instrument provides readings in “Sheffield units”, convert each reading to an air flow rate in millilitres per minute, using the calibration graph prepared as described in A.2.4 ISO 2013 All rights reservedBS ISO 5636-4:2013ISO 5636-4:2013(E)Calculate t
