1、BRITISH STANDARD BS 5131-2.1: 1991 Methods of test for Footwear and footwear materials Part 2: Solings Section 2.1Ross flexing method for cut growth resistance of soling materials NOTEIt is recommended that this Section should be read in conjunction with BS5131-0, publishedseparately.BS5131-2.1:1991
2、 This British Standard, having been prepared under the directionof the Textiles and Clothing Standards Policy Committee, was published underthe authority of the BoardofBSI and comes into effect on 31January1991 BSI 09-1999 First published December1979 Second edition January1991 The following BSI ref
3、erences relate to the work on this standard: Committee reference TCM/39 Draft for comment89/36220 DC ISBN 0 580 18711 X Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Textiles and Clothing Standards Policy Committee (TCM/-) to Technical
4、 Committee TCM/39, upon which the following bodies were represented: British Footwear Manufacturers Federation British Leather Confederation British Rubber Manufacturers Association British Steel plc Consumer Standards Advisory Committee of BSI Cork Industry Federation Footwear Components Federation
5、 Footwear Distributors Federation Institute of Trading Standards Administration Iron and Steel Trades Confederation Lancashire Footwear Manufacturers Association Mail Order Traders Association of Great Britain Ministry of Defence National Union of Footwear, Leather and Allied Trades Office of Fair T
6、rading SATRA Footwear Technology Centre The following bodies were also represented in the drafting of the standard, through subcommittees and panels: British Adhesives and Sealants Association British Paper and Board Industry Federation British Plastics Federation Multiple Shoe Retailers Association
7、 RAPRA Technology Ltd. Amendments issued since publication Amd. No. Date CommentsBS5131-2.1:1991 BSI 09-1999 i Contents Page Committees responsible Inside front cover Foreword ii 1 Scope 1 2 Principle 1 3 Apparatus 1 4 Preparation of test specimens 2 5 Conditioning and testing temperature 3 6 Proced
8、ure 3 7 Expression of results 4 8 Test report 4 Figure 2.1/1 Flexing apparatus 5 Figure 2.1/2 Details of chisel 6 Publication(s) referred to Inside back coverBS5131-2.1:1991 ii BSI 09-1999 Foreword This Section of BS5131 has been prepared under the direction of the Textiles and Clothing Standards Po
9、licy Committee. It supersedes BS5131-2.1:1979, which is withdrawn. 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. Compliance with a British Standard does not of itself confer immunit
10、y 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 amendments incorporated. This will be indicated in the amendm
11、ent table on the inside front cover.BS5131-2.1:1991 BSI 09-1999 1 1 Scope This Section of BS5131 describes a method for determining the resistance of soling material to cut growth resulting from flexing. The test is primarily intended for testing the unpatterned soling material, i.e.using a specimen
12、 of defined length, width and thickness made from the soling material. In addition however, the method sets out conditions for testing whole soles (which may also be patterned) to assess the cut growth performance of the entire sole when flexed at a critical point of the pattern. The test gives a go
13、od indication of the performance of the soling material in normal use and a reasonable indication of the performance of whole soles in normal use. However, in the case of polyurethane soles (especially those which are patterned) the method does not always predict sole cracking. Furthermore, the meth
14、od is not suitable for testing specimens of material greater than15mm thickness. When carrying out this test, a decision is made as to which of two temperatures is appropriate, either room temperature or5 C. The appropriate temperature is that at which the material is least resistant to cut growth.
15、Most materials are less resistant to cut growth at lower temperatures. As a consequence, where the soling material consists of either rubber, resin rubber, polyvinyl chloride (PVC), ethylene vinyl acetate (EVA) or nylon, a temperature of5 C has been chosen. However, where the soling material consist
16、s of thermoplastic rubber, room temperature has been chosen, because resistance to cut growth is less at room temperature than at5 C for this material. NOTEThe titles of the publications referred to in this standard are listed on the inside back page. 2 Principle A test specimen is repeatedly flexed
17、 through90 over a mandrel after a small cut has been made in the test specimen with a chisel. The rate of growth of this cut is a measure of the tendency of the material to crack. A patterned sole may also be flexed, without making the chisel cut, to establish whether a crack or cracks will be initi
18、ated. NOTEThe method is based on the Ross flexing test as described in the American Society for Testing and Materials Method D1052-55 but differs in some important details. 3 Apparatus 1) 3.1 Flexing apparatus, as shown in Figure 2.1/1 a) Principle of operation. Test specimen A is inserted against t
19、he end stop M of the flexing arm B and held by clamp C. The other end of the test specimen is not clamped but moves in and out between rollers D, E and F as the test specimen is flexed, at a rate of605cycles per minute, around mandrel H through90 2 to the position illustrated by the dotted lines. b)
20、 Relevant mechanical details 1) Length JK is505mm. 2) Length JG is11 1.5mm. 3) Mandrel H has a radius of5.0 0.3mm. 4) The tops of rollers E and F and mandrel H are in the same horizontal plane. 5) Roller D is vertically above roller E. 6) The dimensions and positions of rollers D, E and F are not cr
21、itical. A suitable diameter for rollers D and E is25mm and for roller F is10mm or15mm. A suitable distance in plan between the centres of rollers D and E and the centre of mandrel H is30mm, and between the centres of rollers D and E and the centre of roller F is25mm or30mm. 7) The vertical position
22、of roller D is adjustable so that the gap between this and roller E can accommodate: either i) test specimens of various thicknesses; or ii) several test specimens simultaneously. A locking mechanism is provided to ensure that the gap cannot change during a test. 8) Roller F is fitted with a pair of
23、 adjustable collars L whose purpose is to help to position the unclamped end of the test specimen during insertion, so that the test specimen is at right angles to mandrel H, and to maintain it in that position during flexing. The difference between the internal and external diameters of each collar
24、 is approximately10mm. For the standard test specimen, the distance between the collars is25.5mm to26.0mm. NOTEWhen testing complete soles, which usually vary in width, the collars cannot normally be used to position the unclamped end of the sole. 1) For information on the availability of suitable a
25、pparatus to perform this test apply to Enquiry Section, BSI, Linford Wood, Milton Keynes MK146LE, quoting the number of this standard and the clause number referring to the items concerned. Enclose a stamped addressed envelope for reply.BS5131-2.1:1991 2 BSI 09-1999 3.2 Suitable driving mechanism, t
26、o operate the flexing apparatus(3.1) at a rate of60 5cycles per minute. 3.3 Chisel, details of which are shown in Figure 2.1/2. A collar may be fitted to the chisel to ensure that it cannot be inserted more than the maximum distance of7.5mm into the test specimen. 3.4 Mandrel, approximately15mm in d
27、iameter, for flexing the specimen to permit measurement of the cut length. 3.5 Suitable measuring device, accurate to0.1mm, for measuring crack/cut length. 4 Preparation of test specimens NOTE 1Where a material is to be tested, the test specimens prepared from this material are referred to as normal
28、 test specimens. NOTE 2Where a fabricated item (that is, an item consisting of a material already fabricated into a particular shape) is to be tested (for example, a patterned sole), the test specimens consisting of or prepared from the fabricated item are referred to as special test specimens. 4.1
29、Test material of sufficient size 4.1.1 Normal test specimens Prepare the test material using the appropriate method given in BS5131-2.7 so that its thickness is uniform and is as follows according to the nature of the material: a) 3.0 0.2mm for natural and synthetic rubber, resin rubber and nylon; b
30、) 5.0 0.2mm for microcellular rubber, cellular EVA and cellular polyurethane; c) 7.0 0.2mm for thermoplastic rubber and PVC. Cut six normal test specimens252mm wide and1505mm long. Cut three of these so that the length of the normal test specimen is parallel to the length direction of the material a
31、nd cut the other three so that the length of the normal test specimen is at right angles to the length direction of the material. 4.1.2 Special test specimens If it appears that the surface pattern might prevent the special test specimen from moving freely between rollers D and E of the flexing appa
32、ratus(3.1) during flexing, remove a sufficiently thick layer of the pattern to stop this happening. Record the approximate thickness of the layer which has been removed. Ensure that the resulting surface is level. Measure and describe this surface and the thickness of the special test specimen as ac
33、curately as possible, taking into account the nature and depth of the surface pattern (if any) as given in Appendix A.4 of BS5833:1988. Where the fabricated item will suffer flexure in two or more directions when in normal use, cut six special test specimens252mm wide and1505mm long. Cut three of th
34、ese so that the length of the special test specimen is parallel to the length direction of the material and cut the other three so that the length of the special test specimen is at fight angles to the length direction of the material. Where the fabricated item will suffer flexure in one direction o
35、nly when in normal use (as is normally the case for soles) cut three special test specimens252mm wide and150 5mm long. Cut these so that they will be flexed in the same direction as the fabricated item. 4.2 Test material of insufficient size 4.2.1 Necessity for extension pieces If there is insuffici
36、ent material available to produce normal test specimens150mm long, but pieces of material25 2mm wide and100mm long or more can be cut, cut these and extend their length to150mm by attaching suitable extension pieces to one or both ends as described in4.2.2 to produce normal test specimens. Similarly
37、, if the fabricated items are of insufficient size to produce special test specimens150mm long, but pieces of material25 2mm wide and100mm or more long can be cut, cut these and extend their length to150mm by attaching suitable extension pieces to one or both ends as described in4.2.2 to produce spe
38、cial test specimens. 4.2.2 Attachment of extension piece(s) Choose material for the extension pieces that is of the same type and thickness as the soling material to be tested and of approximately the same hardness. Cut the extension pieces252mm wide. Hold the ends of the specimen and extension piec
39、e in contact and fix them together using an office stapler, inserting six or more staples evenly across the joint. Turn the test specimen over and insert six or more staples from the other side. If the staples are proud, place the joint on a hard level surface and gently hammer the staples to make s
40、ure that they are fully clenched and not standing proud. Attach another extension piece to the other end of the test specimen if the combined length has not been increased to150mm.BS5131-2.1:1991 BSI 09-1999 3 4.3 Location and insertion of chisel cut 4.3.1 Normal test specimen Use the chisel(3.3) to
41、 cut right through the normal test specimen or to a depth of7.5 0.5mm, whichever is the smaller. Make the cut in the wearing (outer) surface so that it lies symmetrically across the centreline of the test specimen and is at such a position that the cut can be clamped at position G to within0.5mm as
42、shown in Figure 2.1/1 (i.e.with the average dimensions given in3.1 for the flexing apparatus, make the cut61mm from the end of the test specimen). In the case of normal test specimens with extension pieces, ensure that the cut is not in either of the extension pieces or in the stapled region. NOTETh
43、e vertical aspect of the chisel cut and its correct location is made easier by the use of a jig. 4.3.2 Special test specimens If a chisel cut is to be made, make it in the area of the sole pattern where the maximum degree of strain occurs when the special test specimen is flexed and also at such a p
44、osition that the cut can be clamped at position G shown in Figure 2.1/1. In the case of special test specimens with extension pieces, ensure that the cut is not in either of the extension pieces or in the stapled region. NOTEA chisel cut is made to obtain information about cut growth resistance and
45、spontaneous cracking. If information is required about cut growth resistance of an item, a chisel cut is essential. If information is required about the spontaneous cracking properties of an item, a chisel cut is superfluous. 5 Conditioning and testing temperature 5.1 Conditioning No conditioning of
46、 the test specimens is necessary. 5.2 Testing temperature The standard testing temperature is5 C for all materials except thermoplastic rubber for which the standard test temperature is20 C. 6 Procedure 6.1 Measure and record the initial length of the cut in each test specimen to an accuracy of0.1mm
47、 with the test specimen bent through45 around the15mm diameter mandrel(3.4). NOTEThe cutting edge of the chisel is2mm long but the length of cut produced in the material tends to differ a little from this. 6.2 When the test apparatus is to be used in a refrigerated cabinet adopt the following proced
48、ure to ensure that all test specimens receive the same treatment: a) lay out all the test specimens in the cabinet and note the time; b) load the test specimen into the flexing apparatus in the manner described in6.3; c) commence flexing10min after placing the test specimens in the cabinet. 6.3 Turn
49、 the driving mechanism of the flexing apparatus(3.1) manually until the flexing arm B is horizontal. Raise the top roller D and slacken the clamping plate C. Insert the test specimen(s), wearing (outer) surface uppermost, between collars L on roller F, between rollers D and E, and then between clamp C and flexing arm B. Position the test specimen at right angles to mandrel H and so that the cut is in position G (vertically above the edge of the mandrel) shown in Figure 2.1/1. If the test specimen incorporates extension pieces (see4.2), e
