1、BRITISH STANDARD BS4948:1994 Method for Assessment of the visible soiling by body contact of upholstery fabricsBS4948:1994 This British Standard, havingbeen prepared under thedirection of the Materials andChemicals Sector Board (I/-), was published under the authorityof the Standards Boardand comes
2、into effect on 15 December1994 BSI 09-1999 First published October1973 Second edition December1994 The following BSI references relate to the work on this standard: Committee reference TCI/6 Draft for comment 93/303903 DC ISBN 0 580 23252 2 Committees responsible for this British Standard The prepar
3、ation of this British Standard was entrusted to Technical Committee TCI/6, Upholstery fabrics, upon which the following bodies were represented: Association of Consulting Scientists Association of Master Upholsterers British Furniture Manufacturers Federation British Interior Textiles Association Br
4、itish Retail Consortium British Shops and Stores Association (BSSA) British Textile Confederation Confederation of British Wool Textiles Limited Consumer Policy Committee of BSI Department of Trade and Industry (Consumer Safety Unit, CA Division) Furnishing Design Association Furniture Industry Rese
5、arch Association International Wool Secretariat Local Authority Organizations Mail Order Traders Association National Bed Federation Limited National Wool Textile Export Corporation Scottish Textile and Technical Centre Ltd. Standards Qualitas Furnishing Textile Finishers Association Textile Researc
6、h Council (FCRA) Amendments issued since publication Amd. No. Date CommentsBS4948:1994 BSI 09-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 References 1 3 Principle 1 4 Apparatus 1 5 Atmosphere for conditioning and testing 2 6 Test specimens 2 7 Preparation o
7、f test specimens and standard cotton fabric 2 8 Test procedure 2 9 Assessment of the test specimens 3 10 Test report 4 Annex A (informative) Additional information on apparatus 5 Figure 1 Side view of soiling machine (safety guards removed) 3 Figure A.1 Photoelectric reflectometer 5 List of referenc
8、es Inside back coverBS4948:1994 ii BSI 09-1999 Foreword This British Standard has been prepared by Technical Committee TCI/6, Upholstery fabrics, A background paper describing the development of the test method is published in Textile Institute and Industry,1971, Vol9, No. 12. This edition introduce
9、s technical changes but it does not reflect a full review or revision of the standard, which will be undertaken in due course. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Complian
10、ce with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, pagesi andii, pages1 to6, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had a
11、mendments incorporated. This will be indicated in the amendment table on the inside front cover.BS4948:1994 BSI 09-1999 1 1 Scope This British Standard specifies a method for the assessment of the visible soiling of upholstery fabrics which occurs in those areas which come into direct contact with t
12、he body during use, e.g.upholstered arms, the tops of the backs of some chairs and settees and the lower front edge of seats. Upholstery fabrics the use-surface of which is coated with a plastics material are excluded, as are airborne soiling and staining from other causes. 2 References 2.1 Normativ
13、e references This British Standard incorporates, by dated or undated reference, provisions from other publications. These normative references are made at the appropriate places in the text and the cited publications are listed on the inside back cover. For dated references, only the edition cited a
14、pplies; any subsequent amendments to or revisions of the cited publication apply to this British Standard only when incorporated in the reference by amendment or revision. For undated references, the latest edition of the cited publication applies, together with any amendments. 2.2 Informative refer
15、ences This British Standard refers to other publications that provide information or guidance. Editions of these publications current at the time of issue of this standard are listed on the inside back cover, but reference should be made to the latest editions. 3 Principle A conditioned specimen is
16、mounted in one end of a cylinder containing soiled wool felt cubes. In the opposite end of the cylinder is mounted a piece of standard cotton fabric as used for colour fastness testing. The cylinder is rotated so that the soiled cubes impinge on both fabrics. The test is continued until the measured
17、 reflectance of the standard cotton fabric has decreased by a given extent. The test specimen is then removed and the appearance change which results from the soiling is assessed. 4 Apparatus 4.1 A soiling machine 1) , comprising an even number of cylinders, preferably in multiples of four, mounted
18、so that they can be rotated within a circumscribing diameter of700mm. The cylinders are located with their longest symmetrical axis in the plane of rotation and at right angles to a diameter of the circumscribing circle such that their central point is(240 25)mm from the axis of rotation, measured p
19、erpendicularly. Cylinder dimensions are(100 5)mm internal diameter and(300 10)mm in length. Removable lids are located at each end of the cylinder. The test specimen is secured against the lid by an annular collar of internal diameter not less than75mm. Means of rotating the cylinders at(24 2)rev/mi
20、n shall be provided together with the facility to change the direction of rotation at the end of a10min period of operation (see Figure 1). 4.2 Wool felt cubes 2) , with sides measuring(12.5 0.5)mm and of relative density0.30 to0.40. 4.3 Undyed, desized, bleached cotton cloth, as specified in sectio
21、n FO9 of BS1006:1990, cut into circles of diameter(96 1)mm (see Annex A). At least six will be required. 4.4 Grey scale, for assessing staining in accordance with BS EN20105-A03. 4.5 Photoelectric reflectometer and galvanometer (see Annex A). 4.6 A synthetic sebum, made up from the following: Analyt
22、ical grade quality chemical should be used where available. 4.7 1,1,1-trichloroethane 4.8 Colloidal graphite, having approximately10% graphite in a dispersion which is miscible with white spirit and chloroform. 4.9 White spirit, conforming to BS245. 1) An instrument conforming to these requirements
23、may be obtained from the Furniture Industry Research Association, Maxwell Road, Stevenage, Herts SG12EN 2) For details of source of supply write to Customer Services, Information, BSI,389 Chiswick High Road, London W44AL. 20g coconut oil 26g stearic acid 20g cotton seed oil 36g oleic acid 24g ground
24、 nut oil 40g cholesterol 30g trimyristin 20g myristic alcohol 80g tripalmitin 20g cetyl alcohol 6g tristearin 20g octadecyl alcohol 8g lauric acid 80g liquid paraffin 28g myristic acid (relative density0.83 to0.87) 82g palmitic acid 40g squalene 2)BS4948:1994 2 BSI 09-1999 5 Atmosphere for condition
25、ing and testing The conditioning and testing atmosphere shall conform to the standard atmosphere for testing textiles defined in BS EN20139, i.e.a relative humidity of(65 2)% and a temperature of(20 2) C. 6 Test specimens 6.1 Cut at least four circular test specimens of diameter(96 1)mm from the mat
26、erial under test ensuring that no specimen is taken within50mm of the selvedges. Select the specimens to be truly representative of the overall surface texture of the material under test. 6.2 Cut at least four rectangles of the fabric under test, each measuring50mm 55mm for use in the assessment. 7
27、Preparation of test specimens and standard cotton fabric Expose the test specimens and the circles of standard cotton fabric to the standard atmosphere for testing textiles for at least24h. 8 Test procedure 8.1 General The information given in clause8 relates to a four-cylinder machine, therefore la
28、rger quantities shall be used for larger machines. 8.2 Testing atmosphere Conduct the test in the standard atmosphere for testing textiles. 8.3 Preparation of the soiled cubes 8.3.1 Preparation of soiling mixture Dilute the synthetic sebum (see4.6) in1740ml of1,1,1-trichloroethane (solution1). Carry
29、 out this process and the subsequent soiling of the cubes (see8.3.2) in a fume cupboard equipped with forced draught air circulation vented to the atmosphere outside the building in which the test is being conducted. Dilute10ml of the colloidal graphite dispersion, accurately measured, with100ml of
30、white spirit (solution2). 8.3.2 Soiling of cubes NOTE 1This operation is facilitated if the wool felt cubes are placed in a steel mesh basket of diameter such that it can conveniently fit inside the container of the soiling mixture dispersion. To a mixture of250ml of solution1 and15ml of solution2 a
31、dd20 wool felt cubes and immerse them until they become saturated. NOTE 2This should take approximately3min. Remove the wool cubes, drain them and repeat the process with a further20wool felt cubes. Repeat this process with further batches of20 wool felt cubes until the remaining soiling mixture is
32、inadequate to cover them completely. Allow the soiled wool felt cubes to dry in an oven(60 2) C for not less than2h and not more than4h. Allow the soiled wool felt cubes to cool to room temperature and place them in one cylinder of the soiling machine. Allow the machine to run for at least16h. 8.4 S
33、tandardization of the soiled cubes 8.4.1 Determine the mean value for reflectance of each roll or piece of the unsoiled, standard cotton fabric. 8.4.2 Mount two circular pieces of the standard cotton fabric by means of the annular collars in the lids at opposite ends of the cylinders of the soiling
34、machine, into this same cylinder place40 of the soiled wool felt cubes, fasten the lids in place and run the machine for90min. 8.4.3 At the end of that period remove the pieces of standard cotton fabric and determine the loss of reflectance from the original state. 8.4.4 The loss of reflectance shal
35、l be(25 2) units (based on the0% to100% scale), If the loss in reflectance is less than that specified return the pieces of standard cotton fabric to the cylinder and run the machine for a further15min. If the loss in reflectance is more than that specified discard the cubes and start with a new bat
36、ch. 8.4.5 Continue to determine the reflectance and if the loss has not reached the level specified in8.4.4 repeat the procedure described in8.4.4 until the required level of reflectance is obtained. NOTE 1This level of soiling should be achieved within a period of between1.5h and3h. If the rate of
37、soiling is too slow or too fast reject the soiled cubes and prepare a second batch using a slightly different proportion of the graphite dispersion (solution2) in the soiling medium. If the rate of soiling is too slow slightly increase the volume of the graphite dispersion used and vice versa. NOTE
38、2Normally an alteration of 0.5ml of the diluted graphited dispersion in the soiling mixture constitutes a sufficient correction. NOTE 3When the soiling rate of the batch of40wool felt cubes is satisfactory, a larger number of wool felt cubes may be prepared simultaneously. The volume of soiling mixt
39、ure prepared as described in8.3.1 is suitable for the treatment of a total of160wool felt cubes, and this number can be tumbled together for at least16h in each cylinder of the soiling machine. 8.5 Procedure for test specimens 8.5.1 Ensure that the inner surfaces of each cylinder are clean before th
40、e test is conducted.BS4948:1994 BSI 09-1999 3 8.5.2 For each cylinder of the soiling machine mount a test specimen in one lid and a fresh piece of the standard cotton fabric in the other lid. Place40 of the standardized soiled wool felt cubes in each cylinder, attach the lids and run the machine for
41、 not less than1.5h and not more than3h until the reflectance of the standard cotton fabric has decreased by(25 2) units. Remove the test specimens and vacuum clean them prior to assessment. NOTE 1The vacuum cleaning does not remove the soiling mixture, but it does remove most of the white fibres ori
42、ginating from the wool felt cubes that may be picked up by some types of fabric (notably cut pile fabric and loop raised warp knitted fabrics). NOTE 2The wool felt cubes can usually be used for three soiling tests before their soiling potential falls below the acceptable level. When this occurs, the
43、 soiling power can be increased to an acceptable level by retumbling them overnight as described in8.3.2. Not more than160 wool felt cubes should be placed in each cylinder for the retumbling operation, which can be repeated several times until the wool felt cubes show signs of wear. 9 Assessment of
44、 the test specimens From the centre of each soiled test specimen cut a rectangle measuring50mm 55mm, with its sides in the same directions as the specimens prepared as described in6.2. Mount each rectangle on a card adjacent to a piece of the same dimensions of the unsoiled fabric under test. Assess
45、 the contrast between the soiled and unsoiled pieces of material using the grey scale for staining (see BS EN20105-A03.) Figure 1 Side view of soiling machine (safety guards removed)BS4948:1994 4 BSI 09-1999 10 Test report The report shall state: a) that the test procedure was conducted in accordanc
46、e with this British Standard; b) the number of specimens tested; c) the numerical rating for staining of each test specimen.BS4948:1994 BSI 09-1999 5 Annex A (informative) Additional information on apparatus The photoelectric reflectometer should conform to the following description (see Figure A.1)
47、. The reflectometer consists of an annular selenium barrier layer photoelectric cell, which is positioned with the sensitive surface parallel to and facing the test surface, and a light source which illuminates the test surface through a hole in the centre of the photoelectric cell. The photoelectri
48、c cell is44mm diameter (sensitive area38mm diameter) and the central hole is10mm diameter; the absorption characteristics of the cell are such that it exhibits maximum sensitivity to light at a wavelength of approximately560nm. The cell is held in an electrically insulated plastic housing, so that t
49、he sensitive surface is parallel to and6mm above the plane base of the housing, which in turn rests on the surface under test. The light source, a6volt,6watt automobile type lamp, operated from a constant voltage supply, is enclosed in a ventilated metal lamp-house and positioned symmetrically above the hole in the photoelectric cell, the distance between the lamp filament and the sensitive surface of the cell being approximately25mm. The light beam reaching the test surface is first filtered by a heat-resisting glass filter10mm thick and at least10mm
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