1、BRITISH STANDARD BS EN ISO 7854:1997 BS 3424-9: 1996 Incorporating Amendment No. 1 to BS 3424-9:1996 (renumbers BS as BSEN ISO 7854:1997) Rubber- or plastics-coated fabrics Determination of resistance to damage by flexing The European Standard EN ISO 7854:1997 has the status of a British Standard IC
2、S 59.080.40BSEN ISO 7854:1997 This British Standard, having been prepared under the directionof the Sector Board forMaterials and Chemicals, waspublished under the authorityof the Standards Boardand comes into effect on 15August 1996 BSI 09-1999 First published as BS 3424-9 February 1984 Second edit
3、ion May 1990 Third edition August 1996 The following BSI references relate to the work on this standard: Committee reference PRI/78 Draft for comment 92/38626 DC ISBN 0 580 26001 1 Committees responsible for this British Standard The preparation of this British Standard was entrusted to Technical Co
4、mmittee PRI/78, Coated fabrics, upon which the following bodies were represented: British Clothing Industry Association British Plastics Federation British Rubber Manufacturers Association Ltd. British Textile Technology Group Department of the Environment (Building Research Establishment) Furniture
5、 Industry Research Association Home Office Made-Up Textiles Association Ministry of Defence RAPRA Technology Ltd. SATRA Footwear Technology Centre Society of British Aerospace Companies Limited Society of Motor Manufacturers and Traders Limited Textile Institute Amendments issued since publication A
6、md. No. Date Comments 9617 August 1997 Indicated by a sideline in the marginBSEN ISO 7854:1997 BSI 09-1999 i Contents Page Committees responsible Inside front cover National foreword ii Foreword 2 Introduction 3 1 Scope 3 2 Normative references 4 3 Method A De Mattia method 4 4 Method B Schildknecht
7、 method 5 5 Method C Crumple/flex method 7 6 Analysis of flexing damage 9 Annex A (informative) Recommendations for conducting flex testing on wet test pieces 11 Annex ZA (normative) Normative references to international publications with their relevant European publications 11 National annex NA (in
8、formative) Details of SATRA method 12 Figure 1 Illustration of folding and configuration of test piece for De Mattia method 5 Figure 2 Mounting the test pieces 6 Figure 3 Illustrative diagram of crumple/flex apparatus 8 Figure 4 Configuration of test piece for crumple/flex method 8 Figure 5 Selectio
9、n of test pieces for hydrostatic-head testing from crumple/flex test pieces 9 Figure NA.1 Folded test specimens in clamps in open position 13 Figure NA.2 Vertical plane through centre line of test specimen 13 Figure NA.3 Crease pattern formed by flexing 13 List of references Inside back coverBSEN IS
10、O 7854:1997 ii BSI 09-1999 National foreword This British Standard has been prepared by Technical Committee PRI/78 and is the English language version of EN ISO7854:1997 Rubber- or plastics-coated fabrics Determination of resistance to damage by flexing, published by the European Committee for Stand
11、ardization (CEN). It is identical with ISO7854:1995 published by the International Organization for Standardization (ISO). It supersedes BSENISO7854:1997 which is withdrawn. Additional information. In the 1990 edition of this Part of BS3424 was included method11C which described a dynamic flex test
12、using the SATRA vamp tester. This method is not described in ISO7854 and is retained in a national annex to this edition. Subclauses 3.4, 4.4 and 5.4 of ISO7854 refer to atmosphere A, B or C of ISO2231:1989. In the UK the standard atmosphere is atmosphere A. WARNING. Mechanical guarding of apparatus
13、 should conform to current legislation and with BS5304. Means may need to be provided when testing some types of coating or substrate for exhaust ventilation at the apparatus to control injurious or offensive dust or vapour. Air flow quantities should be sufficient to conform to all relevant safety
14、legislation. 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 immunity from legal obligations. Cross-references Publication
15、 referred to Corresponding British Standard ISO 132:1983 BS 903 Physical testing of rubber Part A10:1984 Determination of flex cracking (DeMattia) (Identical) ISO 2231:1989 BS EN ISO 2231:1995 Rubber- or plastics-coated fabrics. Standard atmospheres for conditioning and testing (Identical) ISO 2286:
16、1986 BS EN 22286:1994 Methods for the determination of length and width of a roll, net mass and mean mass per unit area of a piece, cut, roll or sample and the determination of thickness for coated fabrics (Identical) Summary of pages This document comprises a front cover, an inside front cover, pag
17、es i and ii, theEN ISOtitle page, pages 2 to 14, 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 amendment table on the inside front cover.EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE N
18、ORM EN ISO 7854 March 1997 ICS 83.140 Descriptors: See ISO document English version Rubber- or plastics-coated fabrics Determination of resistance to damage by flexing (ISO 7854:1995) Supports textiles revtus de caoutchouc ou de plastique Dtermination de la rsistance la flexion (ISO7854:1995) Mit Ka
19、utschuk oder Kunststoff beschichtete Textilien Bestimmung der Bestndigkeit gegen Beschdigung durch Biegen (ISO7854:1995) This European Standard was approved by CEN on 1996-12-06. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this
20、European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Central Secretariat or to any CEN member. This European Standard exists in three official versions (Eng
21、lish, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark,
22、Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comit Europen de Normalisation Europisches Komitee fr Normung Central Secretariat: rue de Stassart 36, B-105
23、0 Brussels 1997 Copyright reserved to CEN members Ref. No. EN ISO 7854:1997 EEN ISO 7854:1997 BSI 09-1999 2 Foreword The text of the International Standard from Technical Committee ISO/TC45, Rubber and rubber products, of the International Organization for Standardization (ISO) has been taken over a
24、s an European Standard by Technical Committee CEN/TC248, Textiles and textile products, the secretariat of which is held by BSI. This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by September 1997, and
25、 conflicting national standards shall be withdrawn at the latest by September 1997. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, G
26、reece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. Endorsement notice The text of the International Standard ISO7854:1995 has been approved by CEN as a European Standard without any modification. NOTENormative references to I
27、nternational Standards are listed inAnnex ZA (normative).EN ISO 7854:1997 BSI 09-1999 3 Introduction Investigation of dynamic-flex fatigue properties of coated fabrics has for a number of years suffered from poor repeatability (due in part to the unknown but inevitable variability of the material te
28、sted) and worse reproducibility. Nevertheless, dynamic-flex performance of coated fabrics has been long and widely used as a measure of the product quality. The methods traditionally used suffered from the common deficiency of testing only a small test piece. The De Mattia test is unsuitable for mat
29、erials that exhibit “set”, such as thermoplastics, and the Schildknecht method has disadvantages when testing the heavier industrial fabrics and also tends to require very high geometric ratios and consequently time-consuming tests to verify results. In addition, the mounting of Schildknecht test pi
30、eces can seriously affect test results and repeatability. Both the De Mattia and Schildknecht methods are also uni-directional, which in some cases is advantageous, but in many cases is not appropriate, e.g. where bi-directional stresses are exerted during use. This revised edition of ISO7854 attemp
31、ts to standardize the mounting difficulties associated with the Schildknecht apparatus (method B) and introduces a bi-directional flex fatigue test that provides a large test piece, enabling post-flexing investigations, such as hydrostatic-head tests, to be conducted. The apparatus is described in I
32、SO8096-3:1988, Rubber- or plastics-coated fabrics for water-resistant clothing Specification Part3: Natural rubber- and synthetic rubber-coated fabrics. The apparatus outlined there in illustrative form (see the note to F.1 in AnnexF of ISO8096-3:1988) has been developed in more detail and is now wi
33、dely available commercially from a number of sources. Flex testing can provide a useful indication of the durability of coated fabrics. However, for most applications, flexing conditions induced by these test methods are dissimilar to the conditions met in practice. In particular, the micro-climate
34、induced around the test piece and the thermal stresses induced in the molecular structure of the coating during flexing are unlikely to be representative of practical situations. It is important therefore that these effects be kept to a minimum and their effect be given due consideration when test r
35、esults are being considered. Consequently, it is important to ensure that the air temperature around the test pieces is kept constant during the test. This can be achieved either by maintaining adequate non-forced, open ventilation around the test pieces or by controlling the air temperature within
36、any closed container in which the test apparatus may be mounted. Three methods are described. Method A (De Mattia) may be found suitable for flex testing coated fabrics which cannot be constrained into the configuration required by method B or where the amount of material available for testing is to
37、o small to permit the other methods to be employed. Method B (Schildknecht) will be found useful for flex testing coated fabrics of relatively lightweight construction or whose practical usage would be in the light to medium range in terms of severity of flexing. Method C (crumple/flex test) has bee
38、n found useful in testing coated fabrics which will be subject to severe usage in terms of their flexing capability under arduous conditions. The method requires a large test piece but this provides certain advantages for selecting test pieces for related testing after flexing, e.g. hydrostatic-head
39、 testing. Some coated fabrics are more susceptible to delamination when flexed in the wet state and attention is drawn to the information given inAnnex A. Because of the differences in the nature of the flexing in the three methods, no true correlation of results between the different methods is pos
40、sible. 1 Scope This International Standard describes three methods of assessing the resistance of coated fabrics to damage by repeated flexing.EN ISO 7854:1997 4 BSI 09-1999 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions
41、 of this International Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the standards in
42、dicated below. Members of IEC and ISO maintain registers of currently valid International Standards. ISO 132:1983, Rubber, vulcanized Determination of flex cracking (De Mattia). ISO 1420:1987, Rubber- or plastics-coated fabrics Determination of resistance to penetration by water. ISO 2231:1989, Rubb
43、er- or plastics-coated fabrics Standard atmospheres for conditioning and testing. ISO 2286:1986, Rubber- or plastics-coated fabrics Determination of roll characteristics. 3 Method A De Mattia method 3.1 Principle A rectangular strip of coated fabric is folded twice so that its long edges meet formin
44、g a strip measuring125mm 12,5mm. This folded strip is mounted between a pair of flat grips, one of which reciprocates, causing the folded test piece to be bent outwards five times per second. This high-speed folding of the test piece is continued for either a pre-set number of cycles or until damage
45、 to the test piece is apparent. 3.2 Apparatus 3.2.1 Flex-testing machine, as specified in ISO132, with pairs of flat grips. One of the grips of each pair is capable of a reciprocating motion in a vertical plane with a stroke length of mm and a frequency of5,0Hz 0,2Hz. Each pair of grips is positione
46、d so that they are70mm1mm apart when in the open position and13mm 0,5mm apart when in the closed position. 3.3 Preparation of test pieces Select six test pieces each37,5mm 1mm wide 125mm long from the usable width of the roll as defined in ISO2286. Three test pieces shall be selected with their long
47、er dimension in the longitudinal direction of the roll of coated fabric and three test pieces with the longer dimension in the transverse direction of the roll of coated fabric. Test pieces shall be selected from positions evenly spaced across the full width and length of the sample. NOTE 1In the ca
48、se of woven-fabric substrates, as far as possible no two test pieces should contain the same threads of the fabric in the direction to be tested. NOTE 2Together with suitable increases in the width of grips, the test piece size may be increased so as to permit subsequent hydrostatic-head tests to be
49、 conducted. 3.4 Conditioning and testing atmosphere Condition the test pieces in atmosphere A, B or C of ISO2231:1989, and conduct the test in that atmosphere. 3.5 Procedure Fold each test piece twice as illustrated inFigure 1, with the coating to be tested outermost, along lines12,5mm from each of the longer edges and to a width of12,5mm. Mount each folded test piece between a pair of grips whilst they are in the open position so that the test piece is slightly taut and so that the coating on the centre section of th
