1、BSI Standards PublicationBS EN ISO 17236:2016Leather Physical and mechanical tests Determination of extension setBS EN ISO 17236:2016 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN ISO 17236:2016. It supersedes BS EN ISO 17236:2002 which is withdrawn.The UK par
2、ticipation in its preparation was entrusted to Technical Committee TCI/69, Footwear, leather and coated fabrics.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions of a contract. U
3、sers are responsible for its correct application. The British Standards Institution 2016. Published by BSI Standards Limited 2016ISBN 978 0 580 90474 5 ICS 59.140.30 Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under the authori
4、ty of the Standards Policy and Strategy Committee on 31 March 2016.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORMEN ISO 17236 March 2016 ICS 59.140.30 Supersedes EN ISO 17236:2002English Version Leather - Physical and mechanical tests - Determi
5、nation of extension set (ISO 17236:2016) Cuir - Essais physiques et mcaniques - Dtermination de la dformabilit (ISO 17236:2016) Leder - Physikalische und mechanische Prfungen - Bestimmung der bleibenden Dehnung (ISO 17236:2016) This European Standard was approved by CEN on 23 January 2016. CEN membe
6、rs are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this 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 applicatio
7、n to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, 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 CEN-CENELEC Manageme
8、nt Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, L
9、ithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey andUnited Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17,
10、 B-1000 Brussels 2016 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 17236:2016 EBS EN ISO 17236:2016EN ISO 17236:2016 (E) 3 European foreword This document (EN ISO 17236:2016) has been prepared by Technical Committee IULTCS “
11、InternationalUnion of Leather Technologists and Chemists Societies” in collaboration with Technical CommitteeCEN/TC 289 “Leather” the secretariat of which is held by UNI. This European Standard shall be given the status of a national standard, either by publication of anidentical text or by endorsem
12、ent, at the latest by September 2016, and conflicting national standardsshall be withdrawn at the latest by September 2016. Attention is drawn to the possibility that some of the elements of this document may be the subject ofpatent rights. CEN and/or CENELEC shall not be held responsible for identi
13、fying any or all such patentrights. This document supersedes EN ISO 17236:2002. According to the CEN-CENELEC Internal Regulations, the national standards organizations of thefollowing countries are bound to implement this European Standard: Austria, Belgium, Bulgaria,Croatia, Cyprus, Czech Republic,
14、 Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta,Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland,Turkey and the United Kingdom. Endorsement
15、notice The text of ISO 17236:2016 has been approved by CEN as EN ISO 17236:2016 without any modification. BS EN ISO 17236:2016ISO 17236:2016(E)IULTCS/IUP 43:2016(E)Foreword iv1 Scope . 12 Normative references 13 Principle 14 Apparatus . 15 Sampling and sample preparation 26 Procedure. 27 Expression
16、of results 38 Test report . 3 ISO 2016 All rights reserved iiiContents PageBS EN ISO 17236:2016ISO 17236:2016(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards i
17、s normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take par
18、t in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particul
19、ar the different approval criteria needed for the different types of ISO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).Attention is drawn to the possibility that some of the elements of this
20、document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent declarations received (see www.is
21、o.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the WT
22、O principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationISO 17236 was prepared by the Physical Test Commission of the International Union of Leather Technologists and Chemists Societies (IUP Commission, IULTCS) in collaboration with the Europe
23、an Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, the secretariat of which is held by UNI, in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement). It is based on IUP 43 which was published in J. Soc. Leather Tech. Chem. 84, p. 3
24、99, (2000) and confirmed as an official method of the IULTCS in March 2001.IULTCS, originally formed in 1897, is a world-wide organization of professional leather societies to further the advancement of leather science and technology. IULTCS has three Commissions, which are responsible for establish
25、ing international methods for the sampling and testing of leather. ISO recognizes IULTCS as an international standardizing body for the preparation of test methods for leather.This second edition cancels and replaces the first edition (ISO 17236:2002), of which it constitutes a minor revision to ali
26、gn item d) of Clause 8 with ISO 2419:2012.IULTCS/IUP 43:2016(E)iv ISO 2016 All rights reservedBS EN ISO 17236:2016INTERNATIONAL STANDARDISO 17236:2016(E)IULTCS/IUP 43:2016(E)Leather Physical and mechanical tests Determination of extension set1 ScopeThis International Standard specifies a method for
27、determining the extension set of leather. It is intended for use on upholstery leather but is applicable to all flexible leathers.2 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated refer
28、ences, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 2418, Leather Chemical, physical and mechanical and fastness tests Sampling locationISO 2419, Leather Physical and mechanical tests Sample preparation a
29、nd conditioningISO 2589, Leather Physical and mechanical tests Determination of thicknessISO 7500-1, Metallic materials Verification of static uniaxial testing machines Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system3 PrincipleA test piece is r
30、epeatedly extended at a specified rate until the forces reach a predetermined level and the permanent extension is calculated as a percentage of the original length.4 Apparatus4.1 Tensile testing machine, having a force range appropriate to the specimen under test and consisting of a means of record
31、ing the force (4.1.1) and jaws that operate at a uniform speed of separation of 50 mm 5 mm/min.4.1.1 Means of recording the force, to an accuracy as specified by Class 2 of ISO 7500-1.4.1.2 Jaws, minimum length 30 mm in the direction of the applied load, designed to apply constant clamping by mechan
32、ical or pneumatic means. The texture and design of the inside faces of the jaws shall be such that at the maximum load attained in the test, the test piece does not slip at either jaw.4.2 Thickness gauge, as specified in ISO 2589.4.3 Press knife, the inner wall of which is a rectangle 250 mm 5 mm 10
33、,0 mm 0,5 mm, conforming to the requirements of ISO 2419.4.4 Ruler, reading to 0,5 mm.4.5 Stopwatch, reading to 1 s. ISO 2016 All rights reserved 1BS EN ISO 17236:2016ISO 17236:2016(E)5 Sampling and sample preparation5.1 Sample in accordance with ISO 2418.5.2 Cut six test pieces by applying the pres
34、s knife (4.3) to the grain surface. Cut three test pieces with the longer edge parallel to the backbone and three with the longer edge perpendicular to the backbone.NOTE In the case of small skins, the number of test pieces is to be reduced because of the size of the test piece.If there is a require
35、ment for more than two hides or skins to be tested in one batch, then only one test piece in each direction need be taken from each hide or skin, provided that the overall total is not less than three test pieces in each direction.5.3 Condition the test pieces in accordance with ISO 2419.5.4 Measure
36、 the thickness in accordance with ISO 2589.6 Procedure6.1 Mark a line 35 mm 5 mm from each short edge of the test piece with the line parallel to the short edges.6.2 Using the ruler measure the distance, L0, between the two lines to the nearest 1 mm.6.3 Set the jaws of the tensile testing machine (4
37、.1) 200 mm apart. Clamp the test piece in the jaws such that the short edges of the test piece are parallel to the edges of the jaws, and about 25 mm of the test piece is clamped in each jaw. When the test piece is clamped its grain surface shall lie in one plane.6.4 Run the tensile test machine unt
38、il a load of 20,0 N 0,5 N is reached. Immediately this load is reached stop the crosshead and keep the crosshead stopped in that position for 10 s 1 s.NOTE Stopping the crosshead keeps the sample under load although relaxation of the test piece means that the load will fall slightly.6.5 Return the c
39、rosshead to its start position as rapidly as possible.6.6 Repeat 6.4 to 6.5 so that the test piece is subjected to a total of 5 extension cycles.NOTE The cycling of the tensile test machine is carried out manually using the stopwatch for timing or programming the load and timing into the tensile tes
40、t machine.6.7 Remove the test piece from the tensile test machine immediately after the final load cycle (6.4). Start the stopwatch and lay the test piece on a flat surface with the lines applied as described in 6.1 uppermost. 60 s 5 s after removing the test piece from the tensile tester, measure t
41、he distance, L1, between the lines to the nearest 1 mm.6.8 Repeat 6.1 to 6.7 for other test pieces.6.9 If there is slippage of the test piece at either jaw, reject the result and repeat the determination with a new test piece.IULTCS/IUP 43:2016(E)2 ISO 2016 All rights reservedBS EN ISO 17236:2016ISO
42、 17236:2016(E)7 Expression of resultsThe percentage extension set, Es, shall be calculated using Formula (1):ELLLS=()100100(1)whereL1is the final distance between the marks, in millimetres measured as described in 6.7;L0s the initial distance between the marks, in millimetres measured as described i
43、n 6.2.8 Test reportThe test report shall include the following:a) a reference to this International Standard, i.e. ISO 17236;b) the mean percentage extension set, Es, in each direction;c) the mean thickness of the test piece in each direction;d) the standard atmosphere used for conditioning and test
44、ing as given in ISO 2419;e) any deviations from the method specified in this International Standard;f) full details for identification of the sample and any deviation from ISO 2418 with respect to sampling.IULTCS/IUP 43:2016(E) ISO 2016 All rights reserved 3This page deliberately left blankThis page
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