1、BSI Standards PublicationBS ISO 7229:2015Rubber- or plastics-coatedfabrics Measurement of gaspermeabilityBS ISO 7229:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 7229:2015. Itsupersedes BS ISO 7229:1997 which is withdrawn.The UK participation in its pre
2、paration was entrusted to TechnicalCommittee TCI/69, Footwear, leather and coated fabrics.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 contract. Users are responsible for
3、 its correctapplication. The British Standards Institution 2015. Published by BSI StandardsLimited 2015ISBN 978 0 580 85475 0ICS 59.080.40Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and
4、 Strategy Committee on 31 August 2015.Amendments issued since publicationDate Text affectedBS ISO 7229:2015 ISO 2015Rubber- or plastics-coated fabrics Measurement of gas permeabilitySupports textiles revtus de caoutchouc ou de plastique Mesure de la permabilit aux gazINTERNATIONAL STANDARDISO7229Sec
5、ond edition2015-09-01Reference numberISO 7229:2015(E)BS ISO 7229:2015ISO 7229:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in a
6、ny 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 requester.ISO copyright officeCh. de Blan
7、donnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 7229:2015ISO 7229:2015(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Test pieces . 25.1 Shape and dimensions 25.2 Me
8、asurement of thickness 25.3 Number of test pieces . 25.4 Sealing and masking . 25.5 Conditioning 35.6 Test atmosphere 45.7 Gas transmission area . 46 Pressure sensor method . 46.1 Apparatus 46.2 Test gas 56.3 Procedure 66.4 Calculation and expression of results 76.4.1 Gas transmission rate 76.4.2 Ga
9、s permeability coefficient 87 Gas chromatography method 87.1 Apparatus 87.2 Test gas . 107.3 Carrier gas 107.4 Calibration curve 107.5 Procedure . 107.6 Calculation and expression of results. 117.6.1 Gas transmission rate .117.6.2 Gas permeability coefficient . 118 Test report 12Annex A (informative
10、) Gas chromatography method with equal pressure condition .13 ISO 2015 All rights reserved iiiContents PageBS ISO 7229:2015ISO 7229:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparin
11、g 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 liai
12、son 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 Dire
13、ctives, 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 so
14、me 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 declar
15、ations 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 abo
16、ut ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 45, Rubber and rubber products, Subcommittee SC 4, Products (other than hoses).This second edition cancels
17、 and replaces the first edition (ISO 7229:1997), which has been technically revised.iv ISO 2015 All rights reservedBS ISO 7229:2015ISO 7229:2015(E)IntroductionThe measurement of the permeability of rubber-or plastics-coated fabrics to gases is important in the evaluation of materials for products su
18、ch as leisure boats, balloons or hoses, and other gas containers in addition to the materials for seals and diaphragms. The permeability of the material is crucial when a product is exposed to differential pressure conditioned environment in its service field. ISO 2015 All rights reserved vBS ISO 72
19、29:2015BS ISO 7229:2015Rubber- or plastics-coated fabrics Measurement of gas permeabilityWARNING Persons using this document should be familiar with normal laboratory practice. This document does not purport to address all of the safety problems, if any, associated with its use. It is the responsibi
20、lity of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions.1 ScopeThis International Standard specifies two methods for measuring gas transmission through rubber- or plastics-coated fabrics, a property known as permeability.
21、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 references, the latest edition of the referenced document (including any amendm
22、ents) applies.ISO 2231, Rubber- or plastics-coated fabrics Standard atmospheres for conditioning and testingISO 2286-3, Rubber- or plastics-coated fabrics Determination of roll characteristics Part 3: Methods for determination of thickness3 Terms and definitionsFor the purposes of this document, the
23、 following terms and definitions apply.3.1gas transmission ratevolume of test gas passing through a test piece per unit area, per unit time with unit partial-pressure difference between the two sides of the test piece3.2gas permeability coefficientvolume of test gas passing through a test piece of u
24、nit thickness, per unit area, per unit time with unit partial-pressure difference between the two sides of the test piece3.3gas transmission curvein the pressure sensor method, curve plotted against time, of the pressure change on the low pressure side of the test cell until gas transmission reaches
25、 a steady state after starting the testNote 1 to entry: See Figure 3.4 PrincipleA test piece is placed between two parts of a hermetically sealed measurement cell. Each part of the cell is vacuumed, then one part is filled with test gas to a certain pressure level. The quantity of gas that permeates
26、 through the test piece to the lower pressure side is measured and determined by a pressure sensor or by a gas chromatograph. In the gas chromatography method, measurement condition using equal pressure between two parts of the cell divided by the test piece is given for information in Annex A.INTER
27、NATIONAL STANDARD ISO 7229:2015(E) ISO 2015 All rights reserved 1BS ISO 7229:2015ISO 7229:2015(E)5 Test pieces5.1 Shape and dimensionsThe test piece shall be of uniform shape and have a thickness of more than 0,10 mm and less than 4,00 mm. When using test pieces other than this, the thickness shall
28、be agreed between the interested parties. The test piece shall be large enough to cover the full area of the test cell.5.2 Measurement of thicknessMeasure the thickness of the test piece at five or more points including the centre part of the gas transmission area to the nearest 0,01 mm in accordanc
29、e with ISO 2286-3 and take the arithmetic mean.5.3 Number of test piecesThree or more test pieces shall be used.5.4 Sealing and maskingA substrate generally passes gas much more easily than coating materials, and even after the test piece is fixed in the cell, the test gas permeated through the coat
30、ing material may leak out of the cell through the substrate. Cross section cut at the edge around the test piece shall be sealed or masked with wax or a solid type of adhesive which shall not cause any crack nor affect the gas permeability of the test piece during the test.When a test piece of singl
31、e-faced coated fabric is used, the surface of the fabric substrate outside the gas permeability measurement area shall be masked besides the edge as shown in Figure 1.2 ISO 2015 All rights reservedBS ISO 7229:2015ISO 7229:2015(E)Key1 10 mm 150 mm (see 6.1.1) 5 test piece2 gas transmission area A (se
32、e 5.7) 6 wax or adhesives3 sealing and masking zone 7 vessel4 plate to support for test piece 8 heaterFigure 1 Example of the sealing and masking equipment5.5 ConditioningThe minimum time between vulcanization and commencement of conditioning of test pieces shall be 16 h.Unless otherwise required in
33、 the material specification, the material shall be conditioned before testing for 16 h to 24 h using method of conditioning “1” specified in ISO 2231. When using a test piece that can ISO 2015 All rights reserved 3BS ISO 7229:2015ISO 7229:2015(E)be easily affected by moisture, dry it for more than 4
34、8 h at test temperature in a desiccator containing a suitable drying agent such as anhydrous calcium chloride.5.6 Test atmosphere5.6.1 Laboratory conditions shall be (23 2) C (Atmosphere “D”), in accordance with ISO 2231.5.6.2 When conducting test at a temperature different from the standard laborat
35、ory temperature, the temperature shall be agreed between the interested parties. The test temperature shall be recorded.5.7 Gas transmission areaThe gas transmission area A (m2) shall be calculated from the internal diameter of the test cell. If a sealing ring is used, calculate the gas transmission
36、 area from its internal diameter.6 Pressure sensor method6.1 ApparatusThe testing apparatus consists of the test cell, pressure sensors, test gas supply reservoir, vacuum pump and associated pipes and valves. An example of the testing apparatus is shown in Figure 2.6.1.1 Test cell, consisting of a l
37、ow pressure side and a high pressure side, such that when a test piece is mounted in it, the gas transmission area is clearly defined. The high pressure side has an inlet port to supply test gas, and a pressure sensor is connected to the low pressure side to detect the change of pressure caused by t
38、he transmitted gas. The mounting surfaces of the cell touching the sample shall be smooth and flat to prevent leakage of gas. The material of the test cell shall be inactive with regard to the test gas and shall not absorb the gas used. A seal such as an O-ring may be used to seal between the face o
39、f the test cell and the test piece, in which case, the transmission rate of the seal shall be considerably smaller than that of a test piece so that it does not affect the result of gas transmission test. The diameter of the gas transmission surface shall be within the range of 10 mm to 150 mm accor
40、ding to the range of gas transmission rates expected. The cell may be equipped with an electric or hot water heating jacket system capable of raising the temperature up to 80 C. The temperature accuracy shall be controlled within 2 C from 40 C to 80 C.6.1.2 Test piece support, installed in the low p
41、ressure side in order to prevent the deformation of the test piece due to the pressure difference. Any material such as filter paper or wire mesh that does not affect the result of gas transmission test may be used. When using filter paper, paper such as that used in chemical analysis is recommended
42、, of thickness 0,1 mm to 0,3 mm according to the depth of low pressure side of the cell.6.1.3 Pressure sensors, a) to measure the change in pressure on the low pressure side of the cell, capable of reading at least to 5 Pa vacuum gauge with no mercury, an electronic diaphragm-type sensor or other su
43、itable sensor shall be used; b) to measure the pressure of the test gas supply tank, capable of reading at least to 100 Pa.6.1.4 Test gas supply reservoir, with a pressure control system to supply test gas to the high pressure side at a constant pressure. The volume of the reservoir shall be suffici
44、ent to ensure that the pressure drop on the high pressure side due to the transmission of the test gas to the lower pressure side through a test piece is controlled within at least 1 % or less.6.1.5 Vacuum pump, capable of evacuating the test cell to 10 Pa or lower.4 ISO 2015 All rights reservedBS I
45、SO 7229:2015ISO 7229:2015(E)6.1.6 Temperature sensor, installed in the test cell for measuring test temperature, and capable of reading at least to 0,1 C.Key1 test gas tank 9 vacuum pump2 valve 1 10 test piece support3 test gas supply reservoir 11 low pressure side of test cell4 test cell 12 tempera
46、ture sensor5 high pressure side of test cell 13 valve 36 sealing ring 14 pressure sensor7 test piece 15 data processor8 valve 2Figure 2 Example of apparatus for gas permeability measurement (pressure sensor method)6.2 Test gasUse a single gas or a mixture of gases such as air, nitrogen, oxygen, hydr
47、ogen, liquefied petroleum gas (in gaseous form) and coal gas. The purity of the single gas or the purity of each component used in the gas mixture shall be 99,5 % of the volume fraction or higher. When using a gas of purity less than this, it shall be agreed between the interested parties. The test
48、gas shall not include any impurity that can affect the measurement. ISO 2015 All rights reserved 5BS ISO 7229:2015ISO 7229:2015(E)WARNING When using a toxic gas and/or inflammable gas, necessary measures shall be taken in its use and recovery.6.3 Procedure6.3.1 Install a suitable test piece support
49、(10 in Figure 2) on the low pressure side of the test cell.6.3.2 Lightly and uniformly apply vacuum grease to the surface of the test cell where the test piece touches and mount the test piece on this surface without any wrinkle or sag.6.3.3 Place a sealing ring (if used) on the test piece, followed by the upper part of cell. Clamp the two halves of the cell together with uniform pressure so that the test piece is completely sealed in place.6.3.4 When making measurements at a different temperature from a standard la
