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1、A Reference number ISO 6179:1998(E) INTERNATIONAL STANDARD ISO 6179 Third edition 1998-04-01 Rubber, vulcanized or thermoplastic Rubber sheets and rubber-coated fabrics Determination of transmission rate of volatile liquids (gravimetric technique) Caoutchouc vulcanis ou thermoplastique Feuilles de c
2、aoutchouc et supports textiles revtus de caoutchouc Dtermination du taux de transmission des liquides volatils (technique gravimtrique) Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24
3、/2007 22:34:32 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6179:1998(E) ISO 1998 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including photocopying
4、and microfilm, without permission in writing from the publisher. International Organization for Standardization Case postale 56 CH-1211 Genve 20 Switzerland Internetcentraliso.ch X.400c=ch; a=400net; p=iso; o=isocs; s=central Printed in Switzerland ii Foreword ISO (the International Organization for
5、 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 technical committee has been established has the
6、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 electrotechnical standardization. Draft Int
7、ernational Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. International Standard ISO 6179 was prepared by Technical Committee ISO/TC 45, Rub
8、ber and rubber products, Subcommittee SC 2, Physical and degradation tests. This third edition cancels and replaces the second edition (ISO 6179:1989), which has been technically revised. Copyright International Organization for Standardization Provided by IHS under license with ISO Licensee=NASA Te
9、chnical Standards 1/9972545001 Not for Resale, 04/24/2007 22:34:32 MDTNo reproduction or networking permitted without license from IHS -,-,- INTERNATIONAL STANDARD ISOISO 6179:1998(E) 1 Rubber, vulcanized or thermoplastic Rubber sheets and rubber-coated fabrics Determination of transmission rate of
10、volatile liquids (gravimetric technique) WARNING Persons using this International Standard should be familiar with normal laboratory practice. This standard does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appr
11、opriate safety and health practices and to ensure compliance with any national regulatory conditions. 1 Scope This International Standard specifies two methods for determining, by measurement of the transmission rate, the permeability of rubber to volatile liquids diffusing into open air. lt is appl
12、icable only to materials in sheet form and to coated fabrics, having thicknesses of between 0,2 mm and 3,0 mm. It is restricted to transmission rates of more than 0,1 g/m2h. The methods are particularly useful for comparing the relative transmission rates of one liquid through different materials, o
13、r of several liquids through one material. Method A, with refilling, is used when testing mixtures of liquids which give different transmission rates. Method B, with no refilling, is used for a single-component liquid. 2 Normative references The following standards contain provisions which, through
14、reference in this text, constitute provisions of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying
15、 the most recent editions of the standards indicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 188:1998, Rubber, vulcanized or thermoplastic Accelerated ageing and heat resistance tests. ISO 471:1995, Rubber Temperatures, humidities and times fo
16、r conditioning and testing. ISO 2231:1989, Rubber- or plastics-coated fabrics Standard atmospheres for conditioning and testing. ISO 2286-3:1998, Rubber- or plastics-coated fabrics Determination of roll characteristics Part 3: Method for determination of thickness. ISO 3310-1:1990, Test sieves Techn
17、ical requirements and testing Part 1: Test sieves of metal wire cloth. ISO 4648:1991, Rubber, vulcanized or thermoplastic Determination of dimensions of test pieces and products for test purposes. Copyright International Organization for Standardization Provided by IHS under license with ISO License
18、e=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 22:34:32 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6179:1998(E) ISO 2 ISO 4661-1:1993, Rubber, vulcanized or thermoplastic Preparation of samples and test pieces Part 1: Physical tests. NOTE A meth
19、od for the determination of water vapour transmission rate is given in ISO 2528:1995, Sheet materials Determination of water vapour transmission rate Gravimetric (dish) method. 3 Definition For the purposes of this International Standard, the following definition applies. 3.1 transmission rate: The
20、mass, in grams, of a volatile liquid which permeates through each square metre of a rubber test sheet of a given thickness per hour under the test conditions specified in this standard. 4 Apparatus 4.1 Container assembly, consisting of a container for the test liquid, a suitable clamping device for
21、the test piece which does not impose a shearing force on the test piece, and a suitable support for the container, so that the test piece and the test liquid are in contact at all times (with the apparatus inverted after filling), and such as to permit free circulation of air across the surface of t
22、he test piece. The container shall have a volume of 60 cm3 to 100 cm3 and an inlet valve for filling and refilling. NOTE For method B, an inlet valve is not necessary when introducing the test liquid before mounting the test piece in place. The mass of the container, the clamping ring, the test piec
23、e and 50 cm3 of the test liquid shall not exceed the capacity of the balance (4.2). The open end of the container and the hole in the clamping ring shall have a diameter such that approximately 10 cm2 of the surface of the test piece is exposed on each side. A suitable apparatus is shown in figure 1
24、. When testing materials without fabric and with a high transmission rate or when testing at high test temperatures, a circular piece of stainless-steel wire mesh of aperture size 1 mm (in accordance with ISO 3310-1) shall be mounted together with the test piece so as to support the latter on its ou
25、ter surface during the test. 4.2 Balance, with a capacity of at least 200 g and accurate to 1 mg. 4.3 Cabinet oven, complying with the requirements of ISO 188, for tests performed at elevated temperatures. 5 Test pieces 5.1 Preparation The standard test piece shall be circular and cut from a flat sh
26、eet in the way specified in ISO 4661-1. The surface shall be flat, smooth and free from defects. Each test piece shall be of a suitable size to fit the container assembly and to be securely clamped in position. The thickness of each test piece shall be 2 mm 0,2 mm. The difference in the mean thickne
27、ss of test pieces used for comparison tests shall not be more than 0,05 mm. Test pieces may also be cut from finished products made from sheets or coated fabrics. In this case, the thickness shall not be less than 0,2 mm and not more than 3,0 mm. Copyright International Organization for Standardizat
28、ion Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 22:34:32 MDTNo reproduction or networking permitted without license from IHS -,-,- ISOISO 6179:1998(E) 3 5.2 Thickness measurement Measure the thickness of the test pieces in accordan
29、ce with ISO 2286 or ISO 4648, as appropriate. 5.3 Number of test pieces Use at least three test pieces for each test. 6 Time-interval between vulcanization and testing The requirements of ISO 471 shall apply. 7 Conditioning Before the test, condition the test pieces in accordance with ISO 471, or IS
30、O 2231 in the case of coated fabrics, i.e. at 23 C 2 C and (50 5) % relative humidity or 27 C 2 C and (65 5) % relative humidity, depending on national practice. 8 Test conditions 8.1 Temperature The normal test temperature is 23 C 2 C or 27 C 2 C (see clause 7). If, for technical reasons, an elevat
31、ed temperature is required, choose it from the following list of temperatures: 40 C 1 C 55 C 1 C 70 C 1 C 85 C 1 C 100 C 1 C If an elevated test temperature is used, a pressure will be generated within the container, which may have some effect on the results of the determination. Irrespective of the
32、 test temperature, carry out all weighing operations at 23 C 2 C or 27 C 2 C. 8.2 Length of test The preferred test period is 24 h 2 h. Alternatively, for materials having high transmission rates, a shorter test period of 8 h or 16 h is recommended. For materials having low transmission rates, a tes
33、t period of 3 days or 7 days is recommended. NOTE In the case of mixtures of liquids, the test period can be limited by a component with a low concentration and large partial transmission rate. This can cause a rapid change in the composition of the liquid and therefore of the transmission rate. Eac
34、h test period commences immediately after the container has been weighed and placed so that the liquid is in contact with the inner surface of the test piece. lf the test is carried out at elevated temperature, the test period commences immediately after placing the apparatus in the oven, which shal
35、l be not more than 30 min after weighing, and the container shall be allowed to cool to standard temperature (23 C 2 C or 27 C 2 C) at the end of each test period before it is weighed. This cooling period (which is not included in the test period) shall not exceed 1 h. Copyright International Organi
36、zation for Standardization Provided by IHS under license with ISO Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 22:34:32 MDTNo reproduction or networking permitted without license from IHS -,-,- ISO 6179:1998(E) ISO 4 9 Procedure 9.1 Preliminary operations Measure the thi
37、ckness of a test piece, with an accuracy of 0,01 mm, at four points along the circumference of the area exposed to the test liquid and at the centre as specified in ISO 2286 or ISO 4648, as appropriate. If any two measurements differ by more than 0,05 mm, discard the test piece. Report the mean valu
38、e. Put the test piece on the open end of the container, together with the stainless-steel wire mesh if necessary (see 4.1), and close the container with the clamping ring. Take care to avoid damaging or displacing the test piece. If it is not tightly sealed, glue or paste may be used. Using a pipett
39、e or funnel, introduce into the container through one of the filling valves about 50 cm3 of the test liquid. Weigh the container to the nearest 1 mg, place on a suitable support (see 4.1) with the filling valves uppermost and maintain at the test temperature with the test liquid in contact with the
40、inner surface of the test piece for 24 h 2 h. Reweigh at the end of this period (see 8.1). Excessive loss in mass indicates that leakage has occurred due to improper sealing. In such cases, discard the test piece. Carry out all weighing operations at a temperature of 23 C 2 C or 27 C 2 C. 9.2 Method
41、 A After the preliminary operations described in 9.1, empty the container through the filling valves and refill it with approximately 50 cm3 of test liquid. After conditioning for 1 h, weigh the container to the nearest 1 mg, making sure that it is clean and dry on the outside surfaces, to obtain th
42、e mass m1 Maintain the container with the test liquid in contact with the test piece at the test temperature for a period t of 24 h 2 h. Reweigh at the end of this period (see 8.2) to obtain the new mass m2. Calculate the change in mass per unit time, k, in milligrams per hour, for the test piece as
43、 follows: k = (m1 m2)/t Repeat the operations until the value of k for any one of three consecutive 24 h 2 h test periods does not differ by more than 10 % from the mean value km for the three test periods. NOTE Depending on the transmission rate, other test periods may be more suitable (see 8.2). R
44、epeat the procedure with the remaining test pieces, starting in each case at the beginning of 9.1. The mean values km obtained for the three test pieces shall be within 15 % of their median value KM. If this is not the case, repeat the determination and use the full set of data from both determinati
45、ons to calculate the result (see clause 10). 9.3 Method B Determine the rate of change in mass in accordance with 9.1 and 9.2 but without emptying and refilling the container between successive weighings. Copyright International Organization for Standardization Provided by IHS under license with ISO
46、 Licensee=NASA Technical Standards 1/9972545001 Not for Resale, 04/24/2007 22:34:32 MDTNo reproduction or networking permitted without license from IHS -,-,- ISOISO 6179:1998(E) 5 10 Expression of results 10.1 Method of calculation Use the median value KM of the three mean values km to calculate the
47、 transmission rate Q, in g/m2h, as follows: Q = 10 KM/A where KM is the median of the mean values obtained for the individual test pieces, in milligrams per hour; A is the exposed area of the test piece, in square centimetres. 10.2 Graphical method The initial increase in transmission and the subseq
48、uent equilibrium state can be clearly identified from a plot of either mass or rate of change in mass against exposure time. When plotting rate of change in mass, the appropriate point on the time axis is the mid-point of the time interval. 11 Test report The test report shall include the following information: a) a reference to this International Standard; b) all details necessary for identification of the material tested; c) the mean thickness of each test piece and the method of measurement used; d) all deta