BS-ISO-7768-2006.pdf

BRITISH STANDARD BS ISO 7768:2006 Textiles Test method for assessing the smoothness appearance of fabrics after cleansing ICS 59.080.30 ? BS ISO 7768:2006 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 7 March 2006 © BSI 7 March 2006 ISBN 0 580 47936 6 National foreword This British Standard reproduces verbatim ISO 7768:2006 and implements it as the UK national standard. The UK participation in its preparation was entrusted to Technical Committee TCI/82, Textiles Care labelling, dry cleaning, laundering, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international publications referred to in this document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. 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 does not of itself confer immunity from legal obligations. aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to iv, pages 1 to 6, an inside back cover and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. DateComments Reference number ISO 7768:2006(E) INTERNATIONAL STANDARD ISO 7768 Second edition 2006-02-15 Textiles Test method for assessing the smoothness appearance of fabrics after cleansing Textiles Méthode d'essai pour l'évaluation de la régularité d'aspect des étoffes après nettoyage BS ISO 7768:2006 ii iii Contents Page Foreword iv 1Scope . 1 2Normative references. 1 3Principle. 1 4Apparatus 1 5Test specimens. 2 6Procedure 2 7Expression of results . 3 8Test report . 3 Annex A (informative) Precision and accuracy. 6 BS ISO 7768:2006 iv Foreword ISO (the International Organization for 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 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. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International 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. 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. ISO 7768 was prepared by Technical Committee ISO/TC 38, Textiles, Subcommittee SC 2, Cleansing, finishing and water resistance tests. This second edition cancels and replaces the first edition (ISO 7768:1985), which has been technically revised. BS ISO 7768:2006 1 Textiles Test method for assessing the smoothness appearance of fabrics after cleansing 1 Scope This International Standard specifies a method for assessing the retention of the original smooth appearance, after one or several cleansing treatments, of the fabrics tested. This method has been developed for use primarily with type B domestic washing machines, as defined in ISO 6330, in the cleansing process. However, it may be possible to use it with type A machines, as defined in the same International Standard. This test method could be used for judging smoothness appearance after other cleansing processes. NOTE It is recognized that prints and patterns will mask the mussiness present in fabrics. However, this does not detract from the smoothness appearance concept which seeks to provide the consumer with fabrics which require little or no ironing. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 105-A03, Textiles Tests for colour fastness Part A03: Grey scale for assessing staining ISO 139, Textiles Standard atmospheres for conditioning and testing ISO 3175 (all parts), Textiles Professional care, drycleaning and wetcleaning of fabrics and garments ISO 6330, Textiles Domestic washing and drying procedures for textile testing 3 Principle Fabric specimens are subjected to procedures simulating cleansing practices. One of the domestic washing and drying procedures specified in ISO 6330 or one of the professional procedures specified in the series of ISO 3175 is used, as agreed between the interested parties. 4 Apparatus 4.1 Washing and drying apparatus, as specified in ISO 6330, or professional care apparatus, as specified in ISO 3175. 4.2 Lighting The evaluation area shall be a darkened room, using the overhead lighting arrangement shown in Figure 1 and comprising the following items. Lamp dimensions should be chosen to extend beyond the overall surface of a test specimen and replicas, when used for the assessment. BS ISO 7768:2006 2 4.2.1Two CW (cool white) fluorescent lamps, without baffle or glass, a minimum of 2 m in length each, placed side by side. 4.2.2One white enamel reflector, without baffle or glass. 4.2.3One specimen holder. 4.2.4One thick plywood viewing board, painted grey to match No. 2 rating on the grey scale for assessing staining specified in ISO 105-A03. 4.3 Three-dimensional smoothness appearance replicas (see Figure 2) 1). 5 Test specimens Prepare three test specimens, each measuring 38 cm ? 38 cm, cut parallel to the length direction, pinked to prevent fraying and marked to indicate the length direction. 6 Procedure 6.1 Treat each specimen according to one of the cleansing procedures specified in ISO 6330 or ISO 3175, as agreed between the interested parties. 6.2 If required, repeat the selected treatment four times, to give a total of five cycles. 6.3 Condition the test specimens for a minimum of 4 h and maximum of 24 h, according to ISO 139, by hanging each specimen unfolded with the length direction vertical to avoid distortion. 6.4 Evaluation 6.4.1 Three observers shall rate each treated test specimen independently. 6.4.2 Mount the test specimen on the viewing board (4.2.4) as illustrated in Figure 1, with the length direction vertical. Place the three-dimensional plastic replicas (4.3) on each side of the test specimen to facilitate comparative rating. The overhead fluorescent light (4.2.1) shall be the only light source for the viewing board, and all other lights in the room shall be turned off. It has been the experience of many observers that the light reflected from the side walls near the viewing board can interfere with the rating results. It is recommended that the side walls be painted black or that blackout curtains be mounted on either side of the viewing board to eliminate the reflective interference. 6.4.3 The observer shall stand directly in front of the specimen, 1,2 m away from the board. It has been found that normal variations in the height of the observer above and below the arbitrary 1,5 m eye level have no significant effect on the rating given. 6.4.4 Assign the number of the replica which most nearly matches the appearance of the test specimen, or assign ratings midway between those whole-number standards which have no half-number standards separating them, if the appearance of the specimens warrants it (see Table 1). 1) The replicas shown in Figure 2 are for illustrative purposes only. These replicas may be obtained from AATCC Technical Center, One Davis Drive, P O Box 12215, Research Triangle Park, North Carolina 27709-2215 (USA); Tel: 919-549-8141; Fax: +919-549-8933; http:/www.aatcc.org/. This information is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of the product named. Equivalent products may be used if they can be shown to lead to the same results. BS ISO 7768:2006 3 A SA-5 rating is equivalent to the SA-5 replica and represents the smoothest appearance and best retention of original appearance, while a SA-1 rating is equivalent to the SA-1 replica and represents the poorest appearance and poorest retention of original appearance. 6.4.5 Similarly, the observer shall independently rate each of the other two test specimens. The other two observers shall proceed in the same manner, assigning ratings independently. Table 1 Fabric smoothness ratings Rating Appearance SA-5 Equivalent to the SA-5 replica 4,5 Midway between Standard SA-4 and SA-5 SA-4 Equivalent to the SA-4 replica SA-3,5 Equivalent to the SA-3,5 replica SA-3 Equivalent to the SA-3 replica 2,5 Midway between Standard SA-2 and SA-3 SA-2 Equivalent to the SA-2 replica 1,5 Midway between Standard SA-1 and SA-2 SA-1 Equivalent to or worse than the SA-1 replica 7 Expression of results Average the nine observations made by the three observers on the set of three test specimens. Report the average to the nearest half rating. NOTE Data on precision and accuracy are given in Annex A. Because the test procedure described is subjective and ordinal ratings are given, statistics that use frequency distribution as a basis were applied to the data. 8 Test report The test report shall include the following information: a) reference to this International Standard (ISO 7768:2006); b) details of sample evaluated; c) details of the cleansing procedures used; d) the number of cleansing cycles used; e) the fabric smoothness rating as calculated according to Clause 7 and expressed according to Table 1; f) details of any deviation from the specified procedure. BS ISO 7768:2006 4 Dimensions in metres Key 1 replica 2 test specimen 3 board for viewing 4 example of fluorescent lamp placement Figure 1 Lighting equipment for viewing test specimens BS ISO 7768:2006 5 Figure 2 Three-dimensional smoothness appearance replicas BS ISO 7768:2006 6 Annex A (informative) Precision and accuracy Tests were conducted in the USA in 1980 with eight laboratories evaluating four fabrics. The analysis of variance technique was judged not to be applicable to these data because their distribution was not normal and because of the limited and discontinuous scale of replica ratings. The data were analysed by calculating expected laboratory test results from the distribution of individual specimen ratings. From the data, it was determined that single observers rated three specimens on the following frequency: Three specimens to same replica: 0,55 Two specimens to same replica and one different: 0,40 Three specimens different: 0,05 Only rarely did the separation in specimen ratings exceed the next replica step. This is indicative of the high degree of repeatability in observer ratings. From the observer rating distribution, a distribution of laboratory test results was calculated for each replica level with half-ratings included. Precision over the whole SA replica was improved. From the frequency distribution of laboratory test results, a calculation was made of the critical difference, D, between two laboratory test levels. With laboratories at the same level: Critical difference Confidence level D ? 0,17 P ? 0,95 D ? 0,25 P ? 0,99 When two or more laboratories wish to compare test results, it is recommended that laboratory levels be established between them prior to commencing test comparisons. Fabrics of known history and performance may be used for this purpose. Differences between laboratory test results (on the same fabric, under the same washing and drying conditions) equal to or greater than a quarter replica unit are statistically significant at P greater than 0,99. A difference of this magnitude or greater suggests a difference in laboratory levels and indicates a need for the laboratory level comparisons. A true value of smoothness appearance of fabrics after repeated home launderings can be defined only in terms of a test method. There is no independent method for determining the true value. As an estimate of this property, this test has no known bias. BS ISO 7768:2006 blank BS ISO 7768:2006 BSI 389 Chiswick High Road London W4 4AL 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. We would be grateful if anyone finding an inaccuracy or ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: +44 (0)20 8996 9000. Fax: +44 (0)20 8996 7400. 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