1、BRITISH STANDARD BS903-A9: 1988 Methods of testing vulcanized rubber Part A9: Determination of abrasion resistance UDC 678.4.063:678.01:620.178.162BS903-A9:1988 This British Standard, having been prepared under the directionof the Rubber StandardsCommittee, was published under the authority ofthe Bo
2、ard of BSI and comes intoeffect on 29 January1988 BSI07-1999 First published June1940 First revision October1950 First published as BS903-A9 March 1957 First revision The following BSI references relate to the work on this standard: Committee reference RUM/36 Draft for comment 85/37596 DC ISBN 0 580
3、 15919 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted by the Rubber Standards Committee (RUM/-) to Technical Committee RUM/36, upon which the following bodies were represented: British Railways Board British Rubber Manufacturers Association
4、ERA Technology Ltd. GAMBICA (BEAMA Ltd.) Institution of Mechanical Engineers Institution of Water Engineers and Scientists Malaysian Rubber Producers Research Association Ministry of Defence National College of Rubber Technology Rubber and Plastics Research Association of Great Britain SATRA Footwea
5、r Technology Centre Amendments issued since publication Amd. No. Date of issue CommentsBS903-A9:1988 BSI 07-1999 i Contents Page Committees responsible Inside front cover Foreword ii 0 Introduction 1 1 Scope 1 2 Definitions 1 3 Principle of methods 1 4 Standard rubbers 2 5 Conditioning 3 6 Temperatu
6、re of test 3 7 Method A 3 8 Method B 7 9 Method C 9 10 Method D 12 Appendix A Comparison of methods 15 Appendix B Standard rubbers for method A 15 Appendix C Details on a suitable abrasive cloth for method A 16 Figure 1 Schematic illustration of apparatus for method A 4 Figure 2 Hollow drill for pre
7、paration of test pieces 5 Figure 3 Abrasion machine for method B 8 Figure 4 Test piece for abrasion machine for method C 10 Figure 5 Abrasion machine for method C 10 Figure 6 Front elevation of abrasion machine for method D 13 Figure 7 Plan view of abrasion machine for method D 13 Table 1 Standard r
8、ubber compounds 2 Table 2 Running-in and test run revolutions 8 Table 3 Test run times and revolutions 11 Table 4 Comparison of methods 15 Publications referred to Inside back coverBS903-A9:1988 ii BSI 07-1999 Foreword This Part of BS903 has been prepared under the direction of the Rubber Standards
9、Committee and supersedes BS903-A9:1957 which is withdrawn. Four methods (A to D) are described in this Part of BS903, because no single method has been found which will adequately simulate the various conditions to which rubber products may be subjected in service. A comparison of these methods and
10、guidance on which method should be chosen for a particular application is given in Appendix A. Method A is technically equivalent to ISO4649:1985 “Rubber Determination of abrasion resistance using a rotating cylinder drum device”. Method B is a revised version of method C (using an Akron machine) of
11、 the1957edition; the main change in the revised method is the provision, as an option in the procedure, for the application of a dust during the test in order to prevent clogging of the abrasive wheel with rubber debris which would otherwise cause abnormally low losses of material due to abrasion. M
12、ethod C is a revised version of method A (using a Du Pont machine) of the1957edition; the main change in the revised method is that the duration of a test run is now specified either as a time (as in the1957edition) or, alternatively, as a number of revolutions of the abrasive disc. Method D is tech
13、nically similar to ISO5470:1980“Rubber or plastics coated fabrics Determination of abrasion resistance”, but it is applicable to flat rubber sheet instead of coated fabrics. Method B (using a Du Pont machine with constant torque modification) of the1957edition has not been included. Method D (using
14、a Dunlop machine) of the1957edition was deleted by an amendment issued in1974. The methods for determining abrasion resistance are classified into two groups: a) continuous abrasion, for which the whole of the test surface is in contact with the abrading surface throughout the test; and b) discontin
15、uous abrasion, for which any particular part of the test surface is only in intermittent contact with the abrading surface. In each of the methods, rubber is abraded by cutting its surface by asperities. Depending on the method chosen, various abrasives, with different degrees of roughness, are used
16、 The severity of the abrasive action between the rubber and the abrasive surface depends on the contact pressure, the slip velocity and the nature of the abrasive. The presence of particles in the abraded rubber in the interface between the test piece and the abrading surface can cause stickiness a
17、nd variable loss of rubber; each method therefore incorporates a means of removing these particles as they are formed. The discontinuous methods are better in this respect because both the abrading surface and the test piece can be cleaned during the test. The results obtained for various rubbers us
18、ing one particular method may not be comparable (either absolutely or relatively) to those obtained using another method. The expression of a result in the form of an abrasion resistance index, based on the abrasion loss of a standard rubber, is intended to help overcome the problem of the variabili
19、ty of abrasion loss found between different machines operating under essentially the same conditions. The important parameters of each method are compared in Appendix A.BS903-A9:1988 BSI 07-1999 iii A British Standard does not purport to include all the necessary provisions of a contract. Users of B
20、ritish Standards are responsible for their correct application. Compliance 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 toiv, pages1 to16, an inside back cover and a back cover
21、 This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover.iv blankBS903-A9:1988 BSI 07-1999 1 0 Introduction Abrasion is the loss of material (the wear) resulting from frictional action upon
22、 a surface. The resistance of rubbers to abrasion is one of their most important technological properties. However, the analysis of the processes of abrasion and of its measurement under laboratory conditions and in service has proved to be a difficult problem. In performing laboratory tests it is g
23、enerally necessary to obtain a significant amount of abrasion in a short time in order to have measurable mass losses. This has led to tests based on the use of sharp abrasive surfaces of corundum, high loads, and high slip velocities, although these conditions are not characteristic of service. Wea
24、r in service, for example, can take place not only on surfaces with sharp asperities but also on mechanically smooth surfaces such as glass or polished metal. In the case of asperities, the predominant action is that of cutting or tearing of the surface, and loss of material occurs as asperities plo
25、ugh through the surface. It is found that the mass loss is directly related to the sliding distance and to the applied load; it is also very dependent upon the sharpness of the edges of the asperities and upon the hardness of the rubber. With smooth surfaces, abrasion is due to different processes a
26、nd is considered to arise from stress concentrations in the surface associated with the mechanism of friction of polymers. However, abrasion by friction forces between relatively smooth surfaces is not of sufficient interest to justify the preparation of a standard method at the present time. No clo
27、se relationship between the results of an abrasion test and service performance can be inferred. 1 Scope This Part of BS903 describes four methods (A to D) for determining the abrasion resistance of rubber by comparing the wear of the rubber under test with that of a standard rubber under the same c
28、onditions. Methods A and D are applicable to rubbers of any degree of hardness, whilst methods B and C are restricted to rubbers with a hardness in the range55 to95 IRHD. NOTEThe titles of the publications referred to in this standard are listed on the inside back cover. 2 Definitions For the purpos
29、es of this Part of BS903, the following definitions apply. 2.1 abrasion resistance the resistance to wear of a rubber when its surface is subjected to mechanical action the abrasion resistance can be expressed as an abrasion resistance index referred to a standard rubber, and this is applicable to a
30、ll methods. For method A only, an alternative way of expressing the abrasion resistance is as a relative volume loss referred to a calibrated abrasive cloth 2.2 abrasion resistance index the expression of abrasion resistance, being the ratio of the volume loss of a standard rubber to the volume loss
31、 of the rubber under test, determined under the same specified conditions, expressed as a percentage 2.3 relative volume loss the volume loss in cubic millimetres of the test rubber when subjected to abrasion by an abrasive cloth which causes the appropriate standard rubber to lose a mass of200mg un
32、der the conditions of test for method A.1 (see 3.2 and 7.4.1) 2.4 slip velocity the vectorial difference between travelling and circumferential velocities. It is calculated as %v = vsin . 3 Principle of methods 3.1 Method A The flat end of a cylindrical test piece is abraded against the surface of a
33、 rotating drum covered with an abrasive cloth, while the test piece is traversed from one end of the drum to the other to reduce contamination of the cloth. In method A.1 the test piece is held stationary (i.e.non-rotating) in the holder during traverse along the drum. In method A.2 the test piece i
34、s held stationary (i.e.non-rotating) or rotated in a plane tangential to the surface of the drum during its traverse. NOTEThe results of the two types of test may differ.BS903-A9:1988 2 BSI 07-1999 3.2 Method B A rotating test piece in the form of a disc is abraded against an abrasive wheel under a
35、specified load, the planes of the test piece and the wheel being inclined at an angle. A dust is applied, if required, during the test in order to prevent clogging of the abrasive wheel with rubber debris. 3.3 Method C A flat test piece is abraded against a rotating abrasive disc under a specified l
36、oad. 3.4 Method D A flat test piece is subjected to rotary slip between itself and a pair of abrasive wheels. The test is carried out using one of a range of wheel loadings and abrasive surfaces, so that it is possible to choose test conditions that are relevant to conditions experienced in service.
37、 4 Standard rubbers The standard rubber compound to be used in a test shall be one of those listed in Table 1. The mixing and vulcanization procedures for S1 and S2, shall be in accordance with Appendix B and for S3 and S4 shall be in accordance with either Appendix B or BS1674. NOTE 1S1 is identica
38、l to the standard rubber specified in B.1 of ISO4649:1985 and is used as the standard rubber for method A when relative volume loss measurements are required. S2 is identical to the standard rubber specified in B.2 of ISO4649:1985; it replaces standard rubber A (tyre-tread type) in BS903-A9:1957. S3
39、 is a high abrasion resistance compound based on synthetic rubber and may be preferred when highly resistant rubbers are being evaluated. S4 is a rubber of low abrasion resistance and may be preferred when less resistant rubbers are being evaluated; it replaces standard rubber B (sole and heel type)
40、 in BS903-A9:1957. NOTE 2The choice of standard rubber will depend on the application for which the test is being carried out. The four standard rubbers are intended to cover a wide range of abrasion resistance. NOTE 3The variability between different batches of a standard rubber can be minimized by
41、 careful control of mixing and vulcanization. Two batches of the same standard rubber should suffer abrasion losses which agree to within 10% when tested by the same method under the same conditions. To minimize variation, the quality of compounding ingredients should be in accordance with BS4398, w
42、henever this is appropriate. Table 1 Standard rubber compounds Standard rubber S1 S2 S3 S4 Ingredients and their designations Natural rubber (NR), SMR5 Styrene-butadiene rubber (SBR) 1 500 (seenote1) Stearic acid Zinc oxide Oil furnace black (HAF), N330 (seenote3) ISAF black, N220 (see note4) Whitin
43、g (see note5) Di-2-ethylhexylphthalate CBS (see note6) Dibenzthiazyl disulphide sulphur Antioxidant (see note7) Parts by mass 100 50 (see note2) 36 1.2 2.5 1.0 Parts by mass 100 2 5 50 0.5 2.5 1.0 Parts by mass 100 1 3 50 1.0 2.0 1.0 Parts by mass 100 2 5 60 60 3 0.6 2.5 1.0 Vulcanization conditions
44、 Cure time, min Cure temperature, C 30 150 40 140 60 150 40 140 NOTE 1In accordance with International Institute of Synthetic Rubber Producers (IISRP) No.1500. NOTE 299.5%ZnO of9m 2 /g surface area (see BS4398). The standard rubber quality is assessed by the tests described in Appendix B. NOTE 3Desi
45、gnated in accordance with ASTMD1765 “Standard classification system for carbon blacks used in rubber products”. For reference purposes, the current industry reference black should be used, but this may give slightly different results. NOTE 4Designated in accordance with ASTM D1765. NOTE 5Ground lime
46、stone,79%25 4m,99.8%754m. NOTE 6N-cyclohexylbenzothiazole-2-sulphenamide. NOTE 7N-isopropyl-N-phenyl-p-phenylenediamine (IPPD).BS903-A9:1988 BSI 07-1999 3 5 Conditioning For all test purposes, the minimum time between vulcanization and testing shall be16h. For non-product tests, the maximum time bet
47、ween vulcanization and testing shall be4weeks and, for evaluations intended to be comparable, the tests shall be carried out after the same time interval. For product tests, the time between vulcanization and testing shall not exceed3months. When the date of vulcanization is unknown, products shall
48、be tested within2months of receipt. Samples and test pieces shall be conditioned, after any necessary preparation, at a temperature of23 2 C for at least3h and then either measured and tested immediately, or kept at a temperature of 23 2 C until tested. If the preparation involves buffing, the inter
49、val between buffing and testing shall be at least16h but shall not exceed72h. If the test is to be carried out at a temperature other than23 2 C (see clause 6), the test pieces shall be conditioned for a period sufficient to reach substantial temperature equilibrium at the test temperature, immediately prior to testing. For elevated test temperatures this period shall be kept as short as possible in order to avoid ageing the rubber. 6 Temperature of test Unless otherwise specified in the material s
