ISO 811

≠ EDICT ± OF GOVERNMENT In order to promote public education and public safety, equal justice for all, a better informed citizenry, the rule of law, world trade and world peace, this legal document is hereby made available on a noncommercial basis, as it is the right of all humans to know and speak the laws that govern them. EAS 251 (2001) (English): Textile fabrics — Determination of resistance to water penetration — Hydrostatic head test EAS 251:2001 ICS 59.080.30 © EAC 2001 First Edition 2001 EAST AFRICAN STANDARD Textile fabrics — Determination of resistance to water penetration — Hydrostatic head test EAST AFRICAN COMMUNITY EAS 251:2001 ii © EAC 2001 — All rights reserved Foreword Development of the East African Standards has been necessitated by the need for harmonizing requirements governing quality of products and services in East Africa. It is envisaged that through harmonized standardization, trade barriers which are encountered when goods and services are exchanged within the Community will be removed. In order to achieve this objective, the Partner States in the Community through their National Bureaux of Standards, have established an East African Standards Committee. The Committee is composed of representatives of the National Standards Bodies in Partner States, together with the representatives from the private sectors and consumer organizations. Draft East African Standards are circulated to stakeholders through the National Standards Bodies in the Partner States. The comments received are discussed and incorporated before finalization of standards, in accordance with the procedures of the Community. East African Standards are subject to review, to keep pace with technological advances. Users of the East African Standards are therefore expected to ensure that they always have the latest versions of the standards they are implementing. © East African Community 2001 — All rights reserved* East African Community P O Box 1096 Arusha Tanzania Tel: 255 27 2504253/8 Fax: 255-27-2504481/2504255 E-Mail: eac@eachq.org Web: www.each.int * © 2001 EAC — All rights of exploitation in any form and by any means reserved worldwide for EAC Partner States’ NSBs. International Standard 811 INTERNATIONAL ORGANIZATION FOR STANDARDIZATION.ME~YHAPO~HAR OPTAHM3AUMR fl0 CTAH~APTbl3A~WWORGANlSATlON INTERNATIONALE DE NORMALISATION Textile fabrics - Determination of resistance to water penetration - Hydrostatic pressure test Et0 ffes - D&termination de la Gsistance ;i /a p&&ration de l’eau - Essai sous pression h ydrostatique First edition - 1981-10-01 UDC 677.064 : 677.01733 Descriptors : textiles, tests, water resistance tests. Ref. No. lSO811-1981 (E) Price based on 3 pages Foreword IS0 (the International Organization for Standardization) is a worldwide federation of national standards institutes (IS0 member bodies). The work of developing Inter- national Standards is carried out through IS0 technical committees. Every member body interested in a subject for which a technical committee has been set up 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. Draft International Standards adopted by the technical committees are circulated to the member bodies for approval before their acceptance as International Standards by the IS0 Council. International Standard IS0 811 was developped by Technical Committee ISO/TC 38, Textiles, and was circulated to the member bodies in October 1979. It has been approved by the member bodies of the following countries : Australia Belgium Brazil Canada China Cyprus Czechoslovakia Denmark Egypt, Arab Rep. of Finland Germany, F. R. Ghana Hungary India Indonesia Italy Japan Korea, Rep. of Libyan Arab Jamahiriya Mexico Netherlands New Zealand Norway Poland Portugal Romania South Africa, Rep. of Spain Sweden Switzerland Thailand Turkey United Kingdom USA USSR The member body technical grounds of the following country expressed disapproval of the document on France This International Standard cancels and replaces IS0 Recommendation R 811-1968, of which it constitutes a technical revision. 0 International Organization for Standardization, 1981 Printed in Switzerland _-~ - INTERNATIONAL STANDARD IS0 811-1981 (E) Textile fabrics - Determination of resistance to water penetration - Hydrostatic pressure test 1 Scope and field of application This International Standard specifies a hydrostatic pressure method for determining the resistance of fabrics to penetration by water. The method is primarily intended for dense fabrics, e.g. ducks, tarpaulins and tentings. 2 Reference IS0 139, Textiles - Standard atmospheres for conditioning and testing. 3 Principle The hydrostatic head supported by a fabric is a measure of the opposition to the passage of water through the fabric. A specimen is subjected to a steadily increasing pressure of water on one face, under standard conditions, until penetration occurs in three places. The pressure at which the water penetrates the fabric at the third place is noted. The water pressure may be applied from below or from above the test specimen. The chosen alternative should be stated in the test report. The result is immediately relevant to the behaviour of fabric articles which are subjected to water pressure for short or moderate periods of time. 4 Apparatus 4.1 The apparatus used for the test should be designed to comply with the following conditions. 4.1.1 It should be possible to clamp the specimen of fabric in such a way that a) it is horizontal and is not bulging; b) an area of the fabric of 100 cm2 * is subjected to stead- ily increasing water pressure from below or from above the fabric; c) no leakage of water takes place at the clamps during the test period (see annex, clause A. 1); d) the specimen does not slip in the clamps; e) any tendency for penetration to occur at the clamped edge of the specimen is minimised (see annex, clause A.1). 4.1.2 The water in contact with the test specimen should be distilled or fully deionized water maintained at either 20 + 2 OC or 27 + 2 OC. The chosen alternative shall be stated in the test report. (The use of water at the higher temperature will yield lower values of hydrostatic head; the magnitude of this effect may vary from fabric to fabric.) 4.1.3 The rate of increase of water pressure shall be 10 + 0,5 cm or 60 ,+ 3 cmH20/min**. Results obtained by the two different rates may not be the same. The chosen alter- native shall be stated in the test report. 4.1.4 A manometer connected to the testing head(s) should allow pressures to be read to an accuracy of 0,5 cmH20 (see annex, clause A.2). * Equipment which necessitates the use of smaller specimens, such as a circular area of 20 cm? or of square specimens is still in use in some coun- tries. Although these are not strictly in compliance with this International Standard, they may be used for the time being and any variation from a cir- cular specimen of area 100 cm* should be stated in the test report. This is an interim measure and it is intended that this provision be deleted when the standard is reviewed 5 years after publication. ** This relates to pressure in millibars. 1 cmH20 = 1 mbar and 1 cmH20 = 98,066 5 Pa (exactly) (1 mbar = 100 Pa). However, the actual measurement made is in conventional centimetres head of water per minute. IS0 811-1981 (E) 5 Conditioning Conditioning and testing shall be carried out according to IS0 139. If so agreed, conditioning and testing may be carried out in the ambient temperature. 6 Test specimens After receipt, handle the fabric as little as possible, avoid folding it sharply and do not treat it in any way (e.g. by ironing it) other than by conditioning. Take at least five test specimens from different places in the fabric so that they represent the material as fully as possible. The fabric may be tested without cutting specimens. Do not take into account very fine droplets which do not grow after being formed. Do not count subsequent drops which penetrate through the same place in the fabric. Note whether the penetration of water at the third place occurs at the edge of the clamp and reject as unsatisfactory any test in which such penetration occurs at a pressure less than the lowest pressure recorded for the other specimens from the same sample. Test further specimens until the requisite number of satisfactory results is obtained. 8 Calculation and expression of results Calculate the mean of the pressures recorded for the specimens tested according to clause 7. Report the individual results and the mean result in conventional centimetres of water. Areas with deep creases or fold marks shall not be tested. 9 Test report 7 Test procedure The test report shall include the following information : Provide freshly distilled annex, clause A.3). water for each specimen tested a) reference to this International Standard; Wipe all water from the clamping surfaces. Clamp the con- ditioned specimen in the test head so that the face of the fabric will be in contact with the water. The clamping shall be carried out in such a way that water will not be forced through the specimen prior to the start of the test. Subject the specimen immediately to increasing water pressure. Watch continuously for evidence of penetration by water. Record the pressure, as conventional centimetres of water, at which water first appears at the third place in the specimen. The accuracy for recording the pressure shall be the following : - until 1 mH20 : 0,5 cm - more than 1 mH20 and until 2 mH20 : 1 cm b) the atmosphere used (standard tropical or other atmosphere); temperate or standard c) the temperature of the water (20 or 27 OC or other temperature); d) whether the water pressure was applied from below or from above the test specimen; e) the rate of increase of water pressure, (10 or 60 cmH20/min); f) which side of the fabric was tested; g) any variation in size or shape of the test specimen; - more than 2 mH20 : 2 cm h) the individual results and their mean. 2 IS0 811-1981 (E) Annex Advice on conducting the test (Forms part of the standard) A.1 Clamping the specimen(s) With some forms of apparatus, it has been found that correct conditions of clamping can be attained if the clamps are faced with a suitable grade of rubber. A . 2 Manometer a) It is necessary to provide a manometer of suitable range. A manometer which provides for pressures up to 1 mH20 is suitable for fabrics similar in construction to gaberdines; for fabrics of closer construction it is advisable to use a manometer which provides for pressures up to 2 mH20. b) If more than one testing head is used in conjunction with the manometer, means shall be provided for separately disconnecting them. This is to prevent a high rate of leakage through test specimens already penetrated at three places. With most forms of apparatus, such a leakage can markedly reduce the rate of increase of pressure on the remaining specimens still under test. A.3 Provision of clean water surface If the instrument used is of the type in which the water to be used for testing is contained in the testing head(s) and rises to come into contact with the specimen, the surface of the water in the testing head(s) may be cleaned in one of the following ways, stated in order of preference : a) Empty the testing head(s) and refill with sufficient freshly distilled water. b) Allow the distilled water to overflow from the testing head(s) so that the surface of the water is cleared. Sweep the surface of the water with a glass slide freshly coated with paraffin wax. c) Allow the distilled water to overflow from the testing head(s) so that the surface of the water is cleared. A.4 Presence of vapours of volatile organic liquids The presence of vapours of volatile organic liquids, such as diethyl ether, in the laboratory when this test is being carried out can affect the results. EAS 251:2001 © EAC 2001 — All rights reserved