1、BSI Standards Publication BS ISO 7229:2015 Rubber- or plastics-coated fabrics Measurement of gas permeabilityBS ISO 7229:2015 BRITISH STANDARD National foreword This British Standard is the UK implementation of ISO 7229:2015. It supersedes BS ISO 7229:1997 which is withdrawn. The UK participation in
2、 its preparation was entrusted to Technical Committee TCI/69, Footwear, leather and coated fabrics. 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 re
3、sponsible for its correct application. The British Standards Institution 2015. Published by BSI Standards Limited 2015 ISBN 978 0 580 85475 0 ICS 59.080.40 Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the
4、 Standards Policy and Strategy Committee on 31 August 2015. Amendments issued since publication Date Text affectedBS ISO 7229:2015 ISO 2015 Rubber- or plastics-coated fabrics Measurement of gas permeability Supports textiles revtus de caoutchouc ou de plastique Mesure de la permabilit aux gaz INTERN
5、ATIONAL STANDARD ISO 7229 Second edition 2015-09-01 Reference number ISO 7229:2015(E)BS ISO 7229:2015ISO 7229:2015(E)ii ISO 2015 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2015, Published in Switzerland All rights reserved. Unless otherwise specified, no part of this publication may be rep
6、roduced 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 request
7、er. ISO copyright office Ch. de Blandonnet 8 CP 401 CH-1214 Vernier, Geneva, Switzerland Tel. +41 22 749 01 11 Fax +41 22 749 09 47 copyrightiso.org www.iso.orgBS ISO 7229:2015ISO 7229:2015(E)Foreword iv Introduction v 1 Scope . 1 2 Normative references 1 3 T erms and definitions . 1 4 Principle 1 5
8、 Test pieces . 2 5.1 Shape and dimensions 2 5.2 Measurement of thickness 2 5.3 Number of test pieces . 2 5.4 Sealing and masking . 2 5.5 Conditioning 3 5.6 Test atmosphere 4 5.7 Gas transmission area . 4 6 Pressure sensor method . 4 6.1 Apparatus 4 6.2 Test gas 5 6.3 Procedure 6 6.4 Calculation and
9、expression of results 7 6.4.1 Gas transmission rate 7 6.4.2 Gas permeability coefficient 8 7 Gas chromatography method 8 7.1 Apparatus 8 7.2 Test gas .10 7.3 Carrier gas 10 7.4 Calibration curve 10 7.5 Procedure .10 7.6 Calculation and expression of results.11 7.6.1 Gas transmission rate .11 7.6.2 G
10、as permeability coefficient .11 8 Test report 12 Annex A (informative) Gas chromatography method with equal pressure condition .13 ISO 2015 All rights reserved iii Contents PageBS ISO 7229:2015ISO 7229:2015(E) Foreword ISO (the International Organization for Standardization) is a worldwide federatio
11、n 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 technical committee has been established has the right to be represented on that committee.
12、 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 electrotechnical standardization. The procedures used to develop this document and tho
13、se 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 was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (
14、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 patent rights. Details of any patent rights identified during the development of the do
15、cument 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 constitute an endorsement. For an explanation on the meaning of ISO specific terms
16、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 information The committee responsible for this document is ISO/TC 45, Rubber and rubber product
17、s, Subcommittee SC 4, Products (other than hoses). This second edition cancels 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) Introduction The measurement of the permeability of rubber-or plastics-coa
18、ted fabrics to gases is important in the evaluation of materials for products such 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 condi
19、tioned environment in its service field. ISO 2015 All rights reserved vBS ISO 7229:2015BS ISO 7229:2015Rubber- or plastics-coated fabrics Measurement of gas permeability WARNING Persons using this document should be familiar with normal laboratory practice. This document does not purport to address
20、all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory conditions. 1 Scope This International Standard specifies two methods for measuring gas transmi
21、ssion through rubber- or plastics-coated fabrics, a property known as permeability. 2 Normative references The 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 un
22、dated references, the latest edition of the referenced document (including any amendments) applies. ISO 2231, Rubber- or plastics-coated fabrics Standard atmospheres for conditioning and testing ISO 2286-3, Rubber- or plastics-coated fabrics Determination of roll characteristics Part 3: Methods for
23、determination of thickness 3 T erms a nd definiti ons For the purposes of this document, the following terms and definitions apply. 3.1 gas transmission rate volume of test gas passing through a test piece per unit area, per unit time with unit partial-pressure difference between the two sides of th
24、e test piece 3.2 g a s p e r m e a b i l i t y c o e f f i c i e n t volume of test gas passing through a test piece of unit thickness, per unit area, per unit time with unit partial-pressure difference between the two sides of the test piece 3.3 gas transmission curve in the pressure sensor method,
25、 curve plotted against time, of the pressure change on the low pressure side of the test cell until gas transmission reaches a steady state after starting the test Note 1 to entry: See Figure 3. 4 Principle A test piece is placed between two parts of a hermetically sealed measurement cell. Each part
26、 of the cell is vacuumed, then one part is filled with test gas to a certain pressure level. The quantity of gas that permeates 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 c
27、ondition using equal pressure between two parts of the cell divided by the test piece is given for information in Annex A. INTERNATIONAL ST ANDARD ISO 7229:2015(E) ISO 2015 All rights reserved 1BS ISO 7229:2015ISO 7229:2015(E) 5 Test pieces 5.1 Shape and dimensions The test piece shall be of uniform
28、 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 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 thickness Measure the thickne
29、ss 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 accordance with ISO 2286-3 and take the arithmetic mean. 5.3 Number of test pieces Three or more test pieces shall be used. 5.4 Sealing and masking A substrate generally passe
30、s gas much more easily than coating materials, and even after the test piece is fixed in the cell, the test gas permeated through the coating 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 typ
31、e 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 single-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 Fig
32、ure 1.2 ISO 2015 All rights reservedBS ISO 7229:2015ISO 7229:2015(E) Key 1 10 mm 150 mm (see 6.1.1) 5 test piece 2 gas transmission area A (see 5.7) 6 wax or adhesives 3 sealing and masking zone 7 vessel 4 plate to support for test piece 8 heater Figure 1 Example of the sealing and masking equipment
33、 5.5 Conditioning The minimum time between vulcanization and commencement of conditioning of test pieces shall be 16 h. Unless otherwise required in 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. W
34、hen 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 48 h at test temperature in a desiccator containing a suitable drying agent such as anhydrous calcium chloride. 5.6 Test atmosphere 5.6.1 Laboratory con
35、ditions 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 laboratory temperature, the temperature shall be agreed between the interested parties. The test temperature shall be recorded. 5.7 Gas transmission area T
36、he gas transmission area A (m 2 ) shall be calculated from the internal diameter of the test cell. If a sealing ring is used, calculate the gas transmission area from its internal diameter. 6 Pressure sensor method 6.1 Apparatus The testing apparatus consists of the test cell, pressure sensors, test
37、 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 low 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 h
38、igh 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 the transmitted gas. The mounting surfaces of the cell touching the sample shall be smooth and flat to prevent leakage of gas. The material o
39、f 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 of 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
40、 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 according to the range of gas transmission rates expected. The cell may be equipped with an electric or hot water heating jacket system capable o
41、f 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 pressure side in order to prevent the deformation of the test piece due to the pressure difference. Any material such as filter paper or wir
42、e 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, 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 i
43、n 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 suitable 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
44、 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 sufficient 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
45、 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 ISO 7229:2015ISO 7229:2015(E) 6.1.6 Temperature sensor, installed in the test cell for measuring test temperature, and capable of reading
46、 at least to 0,1 C. Key 1 test gas tank 9 vacuum pump 2 valve 1 10 test piece support 3 test gas supply reservoir 11 low pressure side of test cell 4 test cell 12 temperature sensor 5 high pressure side of test cell 13 valve 3 6 sealing ring 14 pressure sensor 7 test piece 15 data processor 8 valve
47、2 Figure 2 Example of apparatus for gas permeability measurement (pressure sensor method) 6.2 Test gas Use a single gas or a mixture of gases such as air, nitrogen, oxygen, hydrogen, liquefied petroleum gas (in gaseous form) and coal gas. The purity of the single gas or the purity of each component
48、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 gas shall not include any impurity that can affect the measurement. ISO 2015 All rights reserved 5BS ISO 7229:2015ISO 7229:
49、2015(E) W A R N I N G W h e n u s i n g a t o x i c g a s a n d / o r i n f l a m m a b l e g a s , n e c e s s a r y m e a s u r e s sh a l l b e t a k e n in its use and recovery. 6.3 Procedure 6.3.1 Install a suitable test piece support (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) o
