BS-3449-1990.pdf

BS 3449:1990 Incorporating Amendment Nos. 1 and 2 Method for resistance of fabrics to water absorption (static immersion test) UDC 677.017; 677.074; 541.121-032.2; 620.1 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI Publishing and copyright information The BSI copyright notice displayed in this document indicates when the document was last issued. © BSI 2006 ISBN 0 580 18162 6 The following BSI references relate to the work on this standard: Committee reference TCM/24 Draft for comment 89/36778 DC Publication history First published December 1961 Second edition, June 1990 Third edition, October 2006 Amendments issued since publication Amd. no.DateText affected 827415 November 1994Clause 4 updated reference; Clause 7.1 replacement formula; references updated from Clause 4. 1665231 October 2006Tolerances added and replacement subclauses in Clause 3.4, tolerances added to Clause 4, second sentence removed Clause 6.7, replacement Clause 6.8. BS 3449:1990 Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI © BSI 2006i BS 3449:1990 Contents Foreword ii 1Scope 1 2Principle 1 3Apparatus and reagent 1 4Atmosphere for conditioning and testing 2 5Test specimens 2 6Procedure 2 7Calculation and expression of results 3 8Test report 3 Appendix Appendix A. Sinkers 4 List of figures Figure 1 Sinker for holding specimen 4 Publications referred to Inside back cover Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 4, an inside back cover and a back cover. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3449:1990 ii© BSI 2006 Foreword Publishing information This British Standard has been prepared under the direction of the Textiles and Clothing Standards Policy Committee and forms a revision of BS 3499:1961, which is withdrawn. In this revision, the method has been brought up to date by making minor changes throughout the text. Contractual and legal considerations This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligation. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI © BSI 20061 BS 3449:1990 1 Scope This British Standard describes a static immersion test which may be applied to any textile fabric for which a knowledge of the water absorportion properties is required. NOTE The titles of the publications referred to in this standard are listed on the inside back cover. 2 Principle Specimens of conditioned fabric of known mass are immersed in water at a constant temperature for a specified length of time. The specimens are held down in a horizontal plane at a given depth below the surface by means of sinkers. The specimens are taken out of the water and surplus water is removed from them by centrifuging, the mass of the specimens is again determined and the absorption percentage is calculated. 3 Apparatus and reagent 3.1 Immersion vessel, of non-corrosive material, at least 130 mm deep, with a flat base, and the base area being large enough to accommodate at least four sinkers. The immersion vessel shall be clean. 3.2 Four sinkers (see Appendix A). 3.3 Balance, to determine mass accurately to 1 mg. 3.4 Centrifuge, comprising a disc with a horizontal mounting surface of diameter 175 ± 2 mm, capable of rotating at 700 ± 10 r/min. The time required to attain the speed of 700 r/min from rest and vice versa shall be between 1 s and 2 s. The disc/pin arrangement should be such that the wet specimens cannot stick to the surface of the disc. This may be achieved by having 50 ribs, each at least 1 mm in height provided in an equally spaced radial arrangement on the surface of the disc, or by ensuring pins are of adequate length. Four steel pins, not less than 6 mm in length and spaced approximately 50 mm away from the centre of the disc, shall be provided in an equally spaced arrangement around the disc to secure the specimens. The total mass of the disc and shaft propelled by the drive motor shall be 410 ± 10 g. The centrifuge shall be provided with a timer to automatically switch off following the prescribed rotation cycle. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3449:1990 2© BSI 2006 3.5 Stop-watch, having an accuracy of ± 1 s. 3.6 Thermometer, complying with BS 593. 3.7 Four light-weight air-tight containers, large enough to accommodate single specimens without creasing. 3.8 Water, complying with grade 3 of BS 3978, at a temperature of 20 ± 2 °C. 4 Atmosphere for conditioning and testing The conditioning and testing atmosphere shall be the standard temperature atmosphere for testing textiles as defined in BS EN 20139, i.e. a relative humidity of 65 ± 2% and a temperature of 20 ± 2 °C. 5 Test specimens 5.1Dimensions Cut each test specimen approximately 80 mm × 80 mm at approximately 45° to the warp or machine direction, avoiding creasing and distortion. 5.2Number Test four test specimens. 5.3Selection Take the test specimens from different places in the fabric, so that they represent the material as fully as possible. 5.4Preparation Remove loose yarns from the test specimen corners and handle the test specimens as little as possible. 6 Procedure 6.1 Condition the test specimens for at least 24 h in the standard temperate atmosphere for testing textiles (see Clause 4). 6.2 After conditioning, record the mass of each test specimen to the nearest milligram. 6.3 Insert one test specimen between the cross-pieces of each of the four sinkers (3.2) with the diagonals of the test specimens in line with the arms of the cross-pieces. 6.4 Add to the immersion vessel (3.1) water (3.8) at 20 ± 2 °C to a depth of at least 100 mm. NOTE Use fresh water (3.8) for each set of four test specimens. Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI © BSI 20063 BS 3449:1990 6.5 Hold the first sinker with the stem vertical so that the test specimen is just clear of the water surface, submerge it carefully to the bottom of the immersion vessel at the same time starting the stop-watch (3.5). Submerge the remaining three sinkers and test specimens at intervals of approximately 1 min. 6.6 If a test specimen becomes displaced appreciably during the process of submerging, restore it to its proper position with the tip of a glass rod; do not touch the water with the hands. NOTE When a test specimen and sinker are submerged, the test specimen, which may be lighter than water because of entrapped air, may press upwards against the underside of the upper arms of the cross-piece. 6.7 Take the first sinker and test specimen out of the water after they have been immersed for a period of 20 min ± 10 s. 6.8 Remove the test specimen from the sinker immediately and locate it on the pins of the centrifuge. Run the centrifuge for (15 ± 1) s to remove loosely attached water. 6.9 Repeat 6.7 to 6.8 with the remaining three sinkers and test specimens after each has been immersed for a period of 20 min ± 10 s. 6.10 Determine the mass of each of the loaded containers to the nearest milligram. 7 Calculation and expression of results 7.1 Calculate the absorption (in %) for each test specimen from the following formula: Absorption = × 100 where M1is the mass of the container (in g); M2is the mass of the container plus wet test specimen (in g); M3is the mass of the conditioned test specimen (in g). 7.2 Calculate the mean percentage water absorption for the four test specimens to the nearest 1%. 8 Test report The test report shall include the following: a)the number and date of this British Standard, i.e. BS 3499:1990; b)the percentage water absorption of each test specimen; c)the mean percentage water absorption to the nearest 1%; d)details of the sample tested. M2M1M3 M3 - - Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3449:1990 4© BSI 2006 Appendix Appendix A. Sinkers NOTE All dimensions are nominal. A sinker is illustrated in Figure 1. It consists of a cross-piece and stem made entirely from 3 mm diameter brass rod. The cross-piece is made by silver-soldering together with four lengths of brass rod which have first been bent into U-shapes and the stem is soldered to the cross-piece. The spacing in the cross-piece is 3 mm and each of the four arms is 65 mm long. The length of the stem is 125 mm. After construction, each sinker is chromium-plated. Figure 1Sinker for holding specimen Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS 3449:1990 Publications referred to BS 593, Specification for laboratory thermometers BS 3978, Specification for water for laboratory use BS EN 20139, Standard atmospheres for conditioning and testing Licensed Copy: sheffieldun sheffieldun, na, Wed Nov 29 07:23:24 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter. Revisions British Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions. It is the constant aim of BSI to improve the quality of our products and services. 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