1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 3376:2011Leather Physical andmechanical tests Determination of tensilestrength and percentageextension (ISO 3376:2011)BS EN ISO 3376:2011 BRITISH STANDARDNational forew
2、ordThis British Standard is the UK implementation of EN ISO 3376:2011.It supersedes BS EN ISO 3376:2002 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee TCI/69, Footwear, leather and coated fabrics.A list of organizations represented on this committee ca
3、n beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012ISBN 978 0 580 67827 1ICS 59.140.30Compliance with a British Standard cannot confer
4、 immunity fromlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 January 2012.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 3376 December 2011 ICS 59.140.30 Supe
5、rsedes EN ISO 3376:2002English Version Leather - Physical and mechanical tests - Determination of tensile strength and percentage extension (ISO 3376:2011) Cuir - Essais physiques et mcaniques - Dtermination de la rsistance la traction et du pourcentage dallongement (ISO 3376:2011) Leder - Physikali
6、sche und mechanische Prfungen - Bestimmung der Zugfestigkeit und der prozentualen Dehnung (ISO 3376:2011) This European Standard was approved by CEN on 14 December 2011. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European
7、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 CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (En
8、glish, 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 Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium
9、, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITT
10、EE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2011 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 3376:2011: EBS EN ISO 3376:2011EN IS
11、O 3376:2011 (E) 3 Foreword This document (EN ISO 3376:2011) has been prepared by Technical Committee CEN/TC 289 “Leather”, the secretariat of which is held by UNI, in collaboration with the International Union of Leather Technologists and Chemists Societies. This European Standard shall be given the
12、 status of a national standard, either by publication of an identical text or by endorsement, at the latest by June 2012, and conflicting national standards shall be withdrawn at the latest by June 2012. Attention is drawn to the possibility that some of the elements of this document may be the subj
13、ect of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN ISO 3376:2002. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement t
14、his European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerla
15、nd and the United Kingdom. BS EN ISO 3376:2011ISO 3376:2011(E) IULTCS/IUP 6:2011(E) ISO 2011 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standa
16、rds is 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 tak
17、e part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is
18、 to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibilit
19、y that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 3376 was prepared by the European Committee for Standardization (CEN) Technical Committee CEN/TC 289, Leather, in collaboration with
20、the Physical Test Commission of the International Union of Leather Technologists and Chemists Societies (IUP Commission, IULTCS), in accordance with the Agreement on technical cooperation between ISO and CEN (Vienna Agreement). IULTCS, originally formed in 1897, is a world-wide organization of profe
21、ssional leather societies to further the advancement of leather science and technology. IULTCS has three Commissions, which are responsible for establishing international methods for the sampling and testing of leather. ISO recognizes IULTCS as an international standardizing body for the preparation
22、 of test methods for leather. This third edition cancels and replaces the second edition (ISO 3376:2002), which has been technically revised in 4.4, 6.2.1, 7.1 and 8. BS EN ISO 3376:2011BS EN ISO 3376:2011INTERNATIONAL STANDARD ISO 3376:2011(E)IULTCS/IUP 6:2011(E) ISO 2011 All rights reserved 1Leath
23、er Physical and mechanical tests Determination of tensile strength and percentage extension 1 Scope This International Standard specifies a method for determining the tensile strength, elongation at a specified load and elongation at break of leather. It is applicable to all types of leather. 2 Norm
24、ative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 2418, Leather Chemical, phys
25、ical and mechanical and fastness tests Sampling location ISO 2419, Leather Physical and mechanical tests Sample preparation and conditioning ISO 2589, Leather Physical and mechanical tests Determination of thickness ISO 7500-1:2004, Metallic materials Verification of static uniaxial testing machines
26、 Part 1: Tension/compression testing machines Verification and calibration of the force-measuring system 3 Principle A test piece is extended at a specified rate until the forces reach a predetermined value or until the test piece breaks. 4 Apparatus 4.1 Tensile testing machine, with: a force range
27、appropriate to the specimen under test; a means of recording the force to an accuracy of at least 2 % as specified by Class 2 of ISO 7500-1; a uniform speed of separation of the jaws of 100 mm/min 20 mm/min; a means of recording the force, e.g. as an extension curve; jaws, minimum length 45 mm in th
28、e direction of the applied load, designed to apply constant clamping by mechanical 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 specimen does not slip in either jaw by an amount exceeding 1 % of the origi
29、nal jaw separation. BS EN ISO 3376:2011ISO 3376:2011(E) IULTCS/IUP 6:2011(E) 2 ISO 2011 All rights reserved4.2 A means of determining the extension of the test piece, either by monitoring the separation of the jaws or by sensors which monitor the separation of two fixed points on the test piece. 4.3
30、 Thickness gauge, as specified in ISO 2589. 4.4 Press knives, as specified in ISO 2419, capable of cutting a test piece as shown in Figure 1 to the dimensions given in Table 1. Figure 1 Shape of test piece Table 1 Dimensions of test pieces Dimensions in millimetres Designation l l1l2b b1R Standard 1
31、10 50 30 10 20 5 Large 190 100 45 20 40 10 4.5 Vernier callipers, reading to 0,1 mm. 5 Sampling and sample preparation 5.1 Sample in accordance with ISO 2418. 5.2 From the sample, cut six test pieces in accordance with ISO 2419 by applying a press knife (4.4) to the grain surface, three test pieces
32、with the longer sides parallel to the backbone and three test pieces with the longer sides perpendicular to the backbone. If previous testing has shown that there is slippage of the test piece in the jaws, use the large press knife (4.4). If there is a requirement for more than two hides or skins to
33、 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. BS EN ISO 3376:2011ISO 3376:2011(E) IULTCS/IUP 6:
34、2011(E) ISO 2011 All rights reserved 36 Procedure 6.1 Determination of dimensions 6.1.1 Using vernier callipers (4.5), measure the width of each test piece to the nearest 0,1 mm at three positions on the grain side and three on the flesh side. In each group of three measurements, make one at the mid
35、-point E (as shown in Figure 1) and the other two at positions approximately midway between the mid-point E and the lines AB and CD. Take the arithmetic mean of the six measurements as the width of the test piece, w. For soft (“flexible”) leather, the width shall be taken as the width of the press k
36、nife. 6.1.2 Measure the thickness of each test piece in accordance with ISO 2589. Make the measurements at three positions, namely the mid-point E and at positions approximately midway between the mid-point E and the lines AB and CD. Take the arithmetic mean of the three measurements as the thicknes
37、s of the test piece, t. 6.2 Determination of tensile strength 6.2.1 Set the jaws of the tensile testing apparatus (4.1) 50 mm 1 mm apart if using the standard test piece or 100 mm apart if using the large test piece. Clamp the test piece in the jaws so that the edges of the jaws lie along the lines
38、AB and CD. When the test piece is clamped, ensure its grain surface lies in one plane. The length axis shall be parallel to the traction direction. 6.2.2 Run the machine until the test piece breaks and record the highest force exerted as the breaking force, F. 6.3 Determination of the percentage elo
39、ngation caused by a specified load 6.3.1 Clamp the test piece between the jaws of the apparatus, as described in 6.2.1. Measure the distance between the jaws at least to the nearest 0,5 mm and record this distance, L0, as the initial length of the test piece for the purpose of the test. 6.3.2 Start
40、the test. Unless the apparatus automatically draws a force/extension curve with the necessary accuracy (see 4.2), follow the distance between the pair of jaws or the sensors as the force increases. 6.3.3 Note the distance, in millimetres, between the pair of jaws or sensors at the instant when the f
41、orce first reaches the specified value. This distance represents the length of the test piece at this force, L1. Do not stop the apparatus if results from the procedures described in 6.2 or 6.4 are also required. 6.4 Determination of the percentage elongation at break 6.4.1 Carry out the steps given
42、 in 6.3.1. 6.4.2 Run the tensile test machine until the test piece breaks. 6.4.3 Record the distance between the jaws or sensors at the instant when rupture of the test piece occurs. This distance represents the length of the test piece at break, L2. 6.5 Slippage If there is slippage of the test pie
43、ce in either jaw when tested according to 6.2, 6.3 or 6.4, and the slippage is greater than 1 % of the initial jaw separation, reject the result and repeat the determination with a new test piece cut using the large press knife (4.4). BS EN ISO 3376:2011ISO 3376:2011(E) IULTCS/IUP 6:2011(E) 4 ISO 20
44、11 All rights reserved7 Expression of results 7.1 Tensile strength The tensile strength, Tn, in MPa (or newtons per square millimetre, if required) shall be calculated using the equation: nFTwtwhere F is the highest force recorded, in newtons; w is the mean width of the test piece, in millimetres; t
45、 is the mean thickness of the test piece, in millimetres. NOTE The relationship between MPa and N/mm2is the following: 1 N/mm2 1 MPa. 7.2 Percentage elongation caused by a specified load The percentage elongation caused by a specified load, E1, shall be calculated using the equation: 1010100LLEL whe
46、re L1is the separation of the jaws or sensors at the specified load; L0is the initial separation of the jaws or sensors. 7.3 Percentage elongation at break The percentage elongation at break, Eb, shall be calculated using the equation: 20b0100LLEL where L2is the separation of the jaws or sensors at
47、break; L0is the initial separation of the jaws or sensors. BS EN ISO 3376:2011ISO 3376:2011(E) IULTCS/IUP 6:2011(E) ISO 2011 All rights reserved 58 Test report The test report shall include the following: a) a reference to this International Standard, i.e. ISO 3376:2011; b) the mean tensile strength
48、, in MPa (or newtons per square millimetre), to the nearest 0,1 MPa, for the test pieces with the longer edge cut parallel to the backbone; c) the mean tensile strength, in MPa (or newtons per square millimetre), to the nearest 0,1 MPa, for the test pieces with the longer edge cut perpendicular to t
49、he backbone; d) the mean percentage elongation at break to the nearest 1 %, for the test pieces with the longer edge cut parallel to the backbone; e) the mean percentage elongation at break to the nearest 1 %, for the test pieces with the longer edge cut perpendicular to the backbone; f) the mean percentage elongation at a specified load to the nearest 1 %, for the test pieces with the longer edge cut parallel to the backbone; if required; g) the mean percentage elongation at a specified load to the n
