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1、BS 8479:2008 Textiles Method for determination of propensity of fabrics to snagging Rotating chamber method ICS 59.080.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW BRITISH STANDARD Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Unco
2、ntrolled Copy, (c) BSI Publishing and copyright information The BSI copyright notice displayed in this document indicates when the document was last issued. BSI 2008 ISBN 978 0 580 56168 9 The following BSI references relate to the work on this standard: Committee reference TCI/24 Draft for comment
3、07/30142621 DC Publication history First published November 2008 Amendments issued since publication Amd. no.DateText affected BS 8479:2008 Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BSI 2008i BS 8479:2008 Contents Foreword ii Int
4、roduction 1 1Scope 1 2Normative references 1 3Terms and definitions 1 4Principle 2 5Apparatus 2 6Preparation of test specimen tubes 5 7Pre-treatment of fabric 7 8Conditioning of fabric 7 9Preparation of test specimens 7 10Procedure 8 11Assessment 8 12Test report 10 Annexes Annex A (informative) Exam
5、ple of the location of test specimens on a length of fabric supplied for test 12 Annex B (informative) Recommendations for periodic cleaning, and for verification, of the test chamber 13 Bibliography 14 List of figures Figure 1 Test chamber 4 Figure 2 Covering of test specimen tubes with felt 6 Figu
6、re A.1 Example of the location of test specimens 12 List of tables Table 1 Grading system 9 Table 2 Classification system for surface defects 9 Summary of pages This document comprises a front cover, an inside front cover, pages i and ii, pages 1 to 14, an inside back cover and a back cover. License
7、d Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BS 8479:2008 ii BSI 2008 Foreword Publishing information This British Standard is published by BSI and came into effect on 3 2008. It was prepared by Technical Committee TCI/24, Physical testing
8、 of textiles. A list of organizations represented on this committee can be obtained on request to its secretary. Information about this document This standard gives a method of test which uses a rotating chamber containing snagging pins to measure the propensity of fabric test samples to snagging. A
9、nother procedure for this test which uses external snagging pins attached to a “mace” is under development. It is envisaged that this procedure will be added to the standard in a future revision. Use of this document It has been assumed in the preparation of this British Standard that the execution
10、of its provisions will be entrusted to appropriately qualified and experienced people, for whose use it has been produced. Presentational conventions The provisions of this standard are presented in roman (i.e. upright) type. Its methods are expressed as a set of instructions, a description, or in s
11、entences in which the principal auxiliary verb is “shall”. Commentary, explanation and general informative material is presented in smaller italic type, and does not constitute a normative element. Contractual and legal considerations This publication does not purport to include all the necessary pr
12、ovisions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. 0 November Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BSI 20081 BS 8479:2
13、008 Introduction Snagging is a phenomenon in which undesirable loops of varying sizes appear on the surface of a garment, usually as a result of the fabric catching on sharp points or objects. Fabrics made of filament yarns, both textured and untextured, are most prone to snagging. However, certain
14、fabrics made of spun staple yarns, and certain fabric structures e.g. satin and sateens, can also be prone to snagging. It is important to be able to measure the propensity of fabrics to snagging so that fabrics with the lowest propensity to snagging can be selected for making garments. 1 Scope This
15、 British Standard gives a method for determining the propensity of fabrics to snagging, and related surface defects. The standard is applicable to knitted and to woven fabrics. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated
16、 references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. BS 3870-1, Stitches and seams Part 1: Classification and terminology of stitch types BS EN ISO 139, Textiles Standard atmospheres for conditioning an
17、d testing BS EN ISO 12947-1, Textiles Determination of the abrasion resistance of fabrics by the Martindale method Part 1: Martindale abrasion testing apparatus 3 Terms and definitions For the purposes of this British Standard the following terms and definitions apply. 3.1snag undesirable loop on th
18、e surface of a woven or knitted fabric NOTE Snags can be of various sizes and are usually the result of the fabric catching on sharp points or objects. 3.2protrusion partially formed snag 3.3filamentation fibrous or hairy appearance on the surface of a fabric due to broken yarn filaments 3.4pulled t
19、hread thread in a fabric that is tighter than the threads adjacent to it Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BS 8479:2008 2 BSI 2008 3.5shiner thread that is more lustrous (and generally tighter) than the threads adjacent t
20、o it NOTE Shiners most commonly occur in fabrics made of continuous filament yarn. They often occur as a result of snagging, as this causes the yarn to be pulled. 3.6indentation concave distortion of the surface of a fabric 4 Principle Specimens of the fabric under test are mounted on felt-covered p
21、olyurethane tubes and tumbled randomly in a test chamber rotating at a constant speed, the inside of which is fitted with rows of pointed pins. The specimens are then examined for the presence of snags and other surface defects. 5 Apparatus 5.1 Test chamber, the inner surface of which has a regular
22、octagonal cross-section, closed at one end and with an openable flap at the other (see Note), as illustrated in Figure 1, with an internal diameter between opposite parallel faces of (224.5 0.3) mm and a depth of (228.0 0.1) mm. NOTE The opening should be sufficiently large to permit access to the i
23、nside of the chamber for cleaning. The inner surface shall be made of a non-absorbent material, such as stainless steel or polypropylene, that is known to be resistant to degradation by generally available cleaning materials. It shall not have any surface finish, such as paint or varnish, that might
24、 be abraded during the tests. The inner surface, including both ends, shall be smooth and free from defects. The chamber shall be fitted with, or to, a device which is able to rotate the chamber about its horizontal axis at a constant speed of (60 2) r/min. The chamber shall be fitted with four line
25、s of inward pointing pins made of metal with a minimum harness value of 58 Rockwell (C scale). Each pin shall have a nominal diameter of (1.0 0.1) mm. The top (1.5 0.1) mm of each pin shall be tapered to a sharp point. The point shall be free from hooks and burrs. Pins with rounded ends shall not be
26、 used. The lines of pins shall run parallel to the long axis of the chamber and shall be evenly spaced round the inner circumference of the chamber. The pins shall either be fitted to a series of bars which are recessed into the chamber wall, or be fixed directly into the chamber wall. The holes int
27、o which the pins are secured shall be blind so that the pins cannot be forced down into the bar or the chamber wall during the test, thus altering their height. Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BSI 20083 BS 8479:2008 The
28、 length of each pin protruding into the chamber, i.e. the length from the tip of the pin to the point at the centre of the pin which is level with the surface of the bar or chamber wall see Figure 1c) shall be (5.0 0.3) mm. The pins shall be inclined at an angle of 60 0.5 to the wall of the chamber
29、in the direction of rotation of the chamber. There shall be 20 pins in each line, spaced (10.0 0.5) mm apart. 5.2 Temperature and humidity controlled room, in which the atmosphere conforms to the standard atmosphere specified in BS EN ISO 139. 5.3 Four polyurethane tubes, (70 1) mm long, inside diam
30、eter (25 1) mm and wall thickness (3 0.5) mm see Figure 2a). 5.4 Four pieces of woven wool felt, conforming to BS EN ISO 12947-1, each piece (70 0.5) mm (110 0.5) mm. 5.5 Double sided adhesive tape, with adhesion properties sufficient to hold the felt onto the tubes. 5.6 Polyurethane or rubber based
31、 adhesive. 5.7 Locking rings, for placing inside the ends of the polyurethane tubes to secure the test specimens during the test procedure, comprising lengths of natural black rubber strip, or similar material, of Shore hardness 50, (88.5 0.5) mm long, (25.0 0.5) mm wide and (2.5 0.5) mm thick. 5.8
32、Lockstitch sewing machine, capable of producing lockstitch type 301 as detailed in BS 3870-1, and fitted with a needle and polyester thread suitable for sewing the fabric under test. NOTE A medium ballpoint needle (size Nm 90, designated in accordance with ISO 8239:1987) and 470 dtex polyester cores
33、pun thread (ticket number 75 or 80 as designated in accordance with BS 4134:1990) are recommended. A preliminary test should be carried out with a double layer of the fabric under test to determine whether this needle and thread can sew the fabric without causing damage or distortion. If damage or d
34、istortion occurs, different needles and threads should be tried until a suitable combination is found. 5.9 Specimen template, comprising a flat piece of rigid material, e.g. acrylic sheet, (140 0.5) mm (140 0.5) mm, approximately 2 mm thick. 5.10 Viewing cabinet, with a matt black surface, fitted wi
35、th a light source comprising a white fluorescent tube or bulb arranged so as to give uniform illumination over the width of the test specimen and masked in such a way that the observer does not look directly into the light when viewing the test specimen. The light source shall be positioned such tha
36、t the light strikes the test specimen at an angle of between 5 and 15 to the plane of the test specimen. NOTE The colour temperature of the light source is not critical. 5.11 Assessment mask, comprising a flat piece of rigid material, e.g. PVC sheet, with a matt black surface, (140 0.5) mm (120 0.5)
37、 mm with an oblong aperture (110 0.5) mm (70 0.5) mm. 5.12 Steel rule or gauge, for measuring the length of snags on the test specimens. Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BS 8479:2008 4 BSI 2008 5.13 Stiff brush, for clea
38、ning fibrous debris off the pins. 5.14 Vacuum cleaning device, for removing dust and debris from the inside of the chamber. Figure 1Test chamber Dimensions in millimetres Key 1 Test chamber 2 Pin bars 3 Pins 4 Device for rotating the test chamber a) Sectional view of test chamber 10.0 0.5 3 2 4 2 1
39、2 228.0 0.1 224.5 0.3 Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BSI 20085 BS 8479:2008 6 Preparation of test specimen tubes Cut a piece of the double sided adhesive tape (5.5) long enough to wrap around one of the polyurethane tu
40、bes (5.3) to give a single layer over the whole surface, excluding the rounded edges at the ends of the tube. Cover the tube with the tape as shown in Figure 2b). Wrap a piece of felt (5.4) around the tube over the adhesive tape, with the shorter sides of the felt parallel to the long axis of the tu
41、be. Press the felt firmly onto the tube so that it sticks securely to the adhesive tape. Apply a layer of adhesive (5.6) to each of the shorter sides of the felt, butt them together and hold them firmly in place until they are stuck see Figure 2c). Figure 1Test chamber (continued) Key 1 Pin bar 2 Pi
42、ns b) Isometric view of a pin bar Linear dimensions in millimetres Key 1 Surface of pin bar 2 Pin 3 Pointed end of pin 4 Flat end of pin fitted into blind hole in pin bar c) Detailed view of a pin 2 1 1 2 3 4 5.0 0.3 1.50.1 60 5 1.00.1 Licensed Copy: London South Bank University, South Bank Universi
43、ty, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BS 8479:2008 6 BSI 2008 Repeat this procedure with the remaining three tubes. If reusing tubes that have been used previously, check the condition of the felt and the tubes before each test. If the felt has lifted away from the tube, if the join has p
44、arted, or if the felt is soiled or damaged, remove the felt and re-cover the tube with a new piece of felt. If the exposed ends of any of the tubes have cracked, discard them and use new tubes. Condition the felt covered tubes in the standard atmosphere (see 5.2) for a minimum of 16 h, and keep them
45、 in the standard atmosphere until needed for the test. Figure 2Covering of test specimen tubes with felt Dimensions in millimetres a) Test specimen tube Key 1 Double sided adhesive tape b) Test specimen tube covered with double sided adhesive tape Key 1 Felt 2 Short ends of felt butted together and
46、glued c) Test specimen tube covered with felt 25 1 3 0.5 70 1 1 1 2 Licensed Copy: London South Bank University, South Bank University, 31/01/2009 03:09, Uncontrolled Copy, (c) BSI BSI 20087 BS 8479:2008 7 Pre-treatment of fabric Unless otherwise agreed between the interested parties, the fabric sha
47、ll be tested as received. If washing or cleaning of the fabric prior to testing is agreed, this shall be carried out as agreed between the interested parties, and the details shall be recorded in the test report. 8 Conditioning of fabric Condition the roll of fabric, swatch or sample length supplied
48、 for testing, in the standard atmosphere (see 5.2) for a minimum of 4 h prior to preparation of the test specimens. 9 Preparation of test specimens 9.1 Using the specimen template (5.9) cut four test specimens (140 0.5) mm (140 0.5) mm from the roll, swatch or length of fabric submitted for testing,
49、 ensuring that where there are different length or width yarns in the fabric these are all represented in each test specimen. 9.2 If the fabric has a pattern, all areas of the pattern shall be included in the test specimens. If it is not possible to include all areas in the four test specimens specified in 9.1 then one or more additional sets of four test specimens shall be prepared in accordance with 9.1. NOTE An example of positioning of t