BS ISO 15106-5-2015 Plastics Film and sheeting Determination of water vapour transmission rate Pressure sensor method《塑料 薄膜和薄板 水蒸汽传递率的测定 压力传感器方法》.pdf

1、BSI Standards PublicationBS ISO 15106-5:2015Plastics Film and sheeting Determination of water vapourtransmission ratePart 5: Pressure sensor methodBS ISO 15106-5:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 15106-5:2015.The UK participation in its prepa

2、ration was entrusted to Technical Committee PRI/75, Plastics and rubber film and sheets.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

3、 its correct application. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 85829 1ICS 83.140.10Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy

4、and Strategy Committee on 30 April 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 15106-5:2015 ISO 2015Plastics Film and sheeting Determination of water vapour transmission rate Part 5: Pressure sensor methodPlastiques Film et feuille Dtermination du coefficien

5、t de transmission de vapeur deau Partie 5: Mthode en pression diffrentielleINTERNATIONAL STANDARDISO15106-5First edition2015-04-15Reference numberISO 15106-5:2015(E)BS ISO 15106-5:2015ISO 15106-5:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2015All rights reserved. Unless o

6、therwise 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 posting on the internet or an intranet, without prior written permission. Permission can be requested from either ISO at the addre

7、ss 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.orgWeb www.iso.orgPublished in SwitzerlandBS ISO 15106-5:2015ISO 15106-5:2015(E)Foreword iv1 Scope . 12 Terms and definitio

8、ns . 13 Principle 14 Test specimens 15 Conditioning 16 Apparatus . 26.1 General . 26.2 Transmission cell 26.3 Pressure sensor 26.4 Water vapour generator 26.5 Cell volume-control device . 26.6 Water . 26.7 Vacuum pump 27 Test conditions . 38 Procedure. 49 Background measurement . 410 Calculation 511

9、 Test result 512 Precision . 513 Test report . 5Bibliography 7 ISO 2015 All rights reserved iiiContents PageBS ISO 15106-5:2015ISO 15106-5:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of p

10、reparing 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,

11、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 those intended for its further maintenance are described in the ISO/I

12、EC 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 (see www.iso.org/directives).Attention is drawn to the possibility

13、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 document will be in the Introduction and/or on the ISO list of patent

14、 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 and expressions related to conformity assessment, as well as informat

15、ion about 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 61, Plastics, Subcommittee SC 11, Products.ISO 15106 consists of the following parts, under the gen

16、eral title Plastics Film and sheeting Determination of water vapour transmission rate: Part 1: Humidity detection sensor method Part 2: Infrared detection sensor method Part 3: Electrolytic detection sensor method Part 4: Gas-chromatographic detection sensor method Part 5: Pressure sensor method Par

17、t 6: Atmospheric pressure ionization mass spectrometer method Part 7: Calcium corrosion methodiv ISO 2015 All rights reservedBS ISO 15106-5:2015Plastics Film and sheeting Determination of water vapour transmission rate Part 5: Pressure sensor method1 ScopeThis part of ISO 15106 specifies a method fo

18、r determining the water vapour transmission rate of plastic film, plastic sheeting, and multi-layer structures including plastics, using a pressure sensor.NOTE The method provides rapid measurement over a wide range of water vapour transmission rates.2 Terms and definitionsFor the purposes of this d

19、ocument, the following terms and definitions apply.2.1water vapour transmission rateamount of water vapour transmitted through unit area of test specimen per unit time under specified conditionsNote 1 to entry: Water vapour transmission rate is expressed in grams per square metre per 24 h g/(m2 24 h

20、).3 PrincipleA test specimen is mounted in a transmission cell (see Figure 1) forming a sealed barrier between two chambers. The upstream chamber is usually the high-pressure side and the downstream chamber is usually the low-pressure side. The downstream chamber and the upstream chamber are evacuat

21、ed after introducing the test specimen into the transmission cell. After the evacuation, water vapour is introduced into the upstream chamber. The water vapour permeates from the upstream chamber to the downstream chamber. The amount of water vapour which permeates through the test specimen is deter

22、mined by the increase of the pressure in the downstream chamber.4 Test specimens4.1 The specimens shall be representative of the material, free from wrinkles, creases and pinholes, and have uniform thickness. Each specimen shall have a larger area than the transmission area of the cell.NOTE Uneven f

23、inal products are not suitable for the specimens to avoid water vapour leakage.4.2 Three specimens shall be tested unless otherwise specified or agreed between the interested parties.5 ConditioningThe specimens shall be conditioned at the same temperature and humidity as specified for the test for a

24、 length of time appropriate to the material under test, unless otherwise agreed between the interested parties.INTERNATIONAL STANDARD ISO 15106-5:2015(E) ISO 2015 All rights reserved 1BS ISO 15106-5:2015ISO 15106-5:2015(E)6 Apparatus6.1 GeneralFigure 1 shows an example of an apparatus for determinin

25、g the water vapour transmission rate using a pressure sensor.The apparatus consists of a water vapour transmission cell designed to allow the water vapour to permeate through a specimen, a pressure sensor to detect the pressure change due to the permeation of the water vapour through the specimen, a

26、 water vapour generator to supply the water vapour to the transmission cell, a cell volume-control device, and a vacuum pump.6.2 Transmission cellThe transmission cell shall consist of an upstream chamber and a downstream chamber designed so that the water vapour transmission area is constant for an

27、y specimen mounted in the transmission cell. The upstream chamber shall have an inlet for the water vapour and the downstream side shall be connected to a pressure sensor. The surfaces in contact with the specimen shall be smooth and flat so that leakage does not occur. The diameter of the water vap

28、our transmission area shall typically be 5 mm to 200 mm.The size of non-circular samples shall be agreed upon by the interested parties.6.3 Pressure sensorThe sensor shall be capable of determining the change in pressure on the downstream side. A minimum sensitivity of 0,2 Pa (0,001 5 mmHg) would be

29、 sufficient for most measurements. A vacuum gauge with no mercury, an electronic diaphragm-type sensor or another suitable type of sensor shall be used.6.4 Water vapour generatorThe water vapour generator is a device to create and store water vapour. The water vapour is fed into the upstream chamber

30、 of the cell from the generator. In order to determine the pressure in the reservoir, a pressure sensor with a minimum sensitivity of 20 Pa (0,15 mmHg) shall be fitted. The water vapour generator shall have sufficient capacity such that permeation of the water vapour through the specimen does not ca

31、use any drop in pressure on the upstream side.6.5 Cell volume-control deviceIn order to extend the transmission rate measurement range, the volume of the downstream chamber can be adjusted by a cell volume control device such as an additional reservoir or an adapter.6.6 WaterThe water used should pr

32、eferably have a purity greater than 99,99 %. The use of water of other purities shall be subject to agreement between the interested parties.6.7 Vacuum pumpA vacuum pump capable of producing an ultimate vacuum of 1 Pa (0,007 5 mmHg) or better shall be used.2 ISO 2015 All rights reservedBS ISO 15106-

33、5:2015ISO 15106-5:2015(E)13671023458911112Key1 transmission cell 8 upstream valve2 upstream volume 9 downstream valve3 downstream volume 10 water vapor generator4 test specimen 11 control valve5 support 12 volume control device with valve6 upstream pressure sensor 13 vacuum pump7 downstream pressure

34、 sensorFigure 1 Example of a water vapour transmission rate measurement apparatus using a pressure sensor7 Test conditionsThe test conditions should preferably be chosen from those given in Table 1.Table 1 Choice of test conditionsTest conditionsTemperatureCRelative humidity%123425 0,540 0,560 0,585

35、 0,590 390 390 385 3Test conditions other than these shall be agreed upon by the interested parties. ISO 2015 All rights reserved 3BS ISO 15106-5:2015ISO 15106-5:2015(E)8 Procedure8.1 Set a permeable support (see 5 in Figure 1) with the diameter and the height of the downstream chamber.8.2 Coat the

36、flat edges of the two halves of the transmission cell thinly and uniformly with vacuum grease for hermetical sealing, and mount the specimen over the downstream chamber so that no creasing or slackness occurs.8.3 Place a rubber sealing ring on the specimen, followed by the upper part of the cell. Cl

37、amp the two halves of the cell together with uniform pressure so that the specimen is completely sealed.8.4 Open the upstream valve and the downstream valve (see 8 and 9 in Figure 1) and start the vacuum pump to evacuate the air from the downstream chamber and the upstream chamber.NOTE The downstrea

38、m chamber is evacuated first to ensure that the specimen fits close to the support.8.5 When a sufficiently low-pressure has been achieved, close the downstream valve and the upstream valve. Switch off the vacuum pump.8.6 Repeat 8.4 to 8.5 if necessary.8.7 Introduce the water vapour into the upstream

39、 chamber by opening control valve (11), shutting off the water vapour supply when the water vapour pressure corresponding to the relative humidity of the test condition has been reached. The pressure in the upstream chamber shall be controlled by the control valve (11) associated with the water vapo

40、ur generator (10).An increase in pressure in the downstream chamber will confirm transmission of the water vapour.8.8 Plot a curve of the pressure in the downstream chamber versus time, continuing until steady-state has been reached as indicated by a straight line.8.9 Determine the slope of the stra

41、ight-line portion of the transmission curve (dp/dt, see Clause 10). An automatically recorded transmission curve can also be used.9 Background measurementFrom time to time a measurement of the background WVTR of the testing cell without sample can be made. For this purpose, a metal plate is put onto

42、 the downstream chamber instead of a test specimen.Thickness of the plate shall be 3 mm to 10 mm and the same material as the testing cell is preferable.4 ISO 2015 All rights reservedBS ISO 15106-5:2015ISO 15106-5:2015(E)10 CalculationCalculate the water vapour transmission rate of the test specimen

43、 using Formula (1):WVTRc=VAMRTdpdt(1)whereWVTR is the water vapour transmission rate of the test specimen, expressed in grams per square metre per 24 h g/(m2 24 h);Vcis the volume of the downstream chamber, expressed in cubic metres;A is the transmission area of the specimen, expressed in square met

44、res;M is the molecular weight of water (= 18,0) g/mol;R is the gas constant (= 8,31) J/(K mol);T is the test temperature, expressed in kelvins;dp/dt is the change in pressure per unit time in the downstream chamber, expressed in pascals per 24 h.11 Test resultExpress the test result as the arithmeti

45、c mean of the results obtained for each test specimen, rounding to two significant figures.If the measured value of the specimens is near the background value, both values shall be reported.12 PrecisionThe precision of this test method is not known because interlaboratory data are not available. Whe

46、n interlaboratory data are obtained, a precision statement will be added at the following revision.13 Test reportThe test report shall include the following information:a) a reference to this part of ISO 15106, i.e. ISO 15106-5;b) the test conditions;c) the name of the apparatus used;d) all details

47、necessary for identification of the sample tested;e) the method of preparation of the test specimens;f) the side of the specimen which faced the supply of water vapour, if necessary;g) the transmission area of the specimen;h) the mean thickness of the specimen;i) the number of specimens tested;j) de

48、tails of specimen conditioning; ISO 2015 All rights reserved 5BS ISO 15106-5:2015ISO 15106-5:2015(E)k) the test result;l) the date of the test.6 ISO 2015 All rights reservedBS ISO 15106-5:2015ISO 15106-5:2015(E)Bibliography1 ISO 4593:1993, Plastics Film and sheeting Determination of thickness by mec

49、hanical scanning ISO 2015 All rights reserved 7BS ISO 15106-5:2015ISO 15106-5:2015(E) ISO 2015 All rights reservedICS 83.140.10Price based on 7 pagesThis page deliberately left blankBSI is the national body responsible for preparing British Standards and other standards-related publications, information and services.BSI is incorporated by Royal Charter. British Standards and other standardization products are published by BSI Standards Limited.British Standards Institution