1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 14087:2011Leather Physical andmechanical tests Determination of bendingforce (ISO 14087:2011)BS EN ISO 14087:2011 BRITISH STANDARDNational forewordThis British Standard
2、 is the UK implementation of EN ISO 14087:2011.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 can beobtained on request to its secretary.This publication does not purport t
3、o include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012ISBN 978 0 580 68693 1ICS 59.140.30Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under th
4、e authority of theStandards Policy and Strategy Committee on 31 January 2012.Amendments issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14087 December 2011 ICS 59.140.30 English Version Leather - Physical and mechanical tests - Determinati
5、on of bending force (ISO 14087:2011) Cuir - Essais physiques et mcaniques - Dtermination de la force de flexion (ISO 14087:2011) Leder - Physikalische und mechanische Prfungen - Bestimmung der Biegekraft (ISO 14087:2011) This European Standard was approved by CEN on 30 November 2011. CEN members are
6、 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 application to t
7、he 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 Management Cen
8、tre 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Nor
9、way, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE 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
10、 and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 14087:2011: EBS EN ISO 14087:2011EN ISO 14087:2011 (E) 3 Foreword This document (EN ISO 14087:2011) has been prepared by Technical Committee CEN/TC 289 “Leather”, the secretariat of which is held by UNI, in collaboration
11、with IULTCS “International Union of Leather Technologists and Chemists Societies“. 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 June 2012, and conflicting national standards shall be withdrawn
12、at the latest by June 2012. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the nat
13、ional standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands
14、, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and the United Kingdom. BS EN ISO 14087:2011ISO 14087:2011(E) IULTCS/IUP 54:2011(E) ISO 2011 All rights reserved iiiForeword ISO (the International Organization for Standardization) is a worldwide federation of natio
15、nal standards bodies (ISO member bodies). The work of preparing International Standards 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. Internati
16、onal organizations, governmental and non-governmental, in liaison with ISO, also take 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 rul
17、es given in the ISO/IEC Directives, Part 2. The main task of technical committees is 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
18、least 75 % of the member bodies casting a vote. Attention is drawn to the possibility 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 14087 was prepared by the Physical Tests Commissi
19、on of the International Union of Leather Technologists and Chemists Societies (IUP Commission, IULTCS) in collaboration with the European Committee for Standardisation (CEN) Technical Committee CEN/TC 289, Leather, the secretariat of which is held by UNI, in accordance with the agreement on technica
20、l co-operation between ISO and CEN (Vienna Agreement). 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 establishing international me
21、thods for the sampling and testing of leather. ISO recognizes IULTCS as an international standardizing body for the preparation of test methods for leather. BS EN ISO 14087:2011BS EN ISO 14087:2011INTERNATIONAL STANDARD ISO 14087:2011(E)IULTCS/IUP 54:2011(E) ISO 2011 All rights reserved 1Leather Phy
22、sical and mechanical tests Determination of bending force 1 Scope This International Standard describes a test method for the determination of the bending force of leather. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated ref
23、erences, 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 location ISO 2419, Leather Physical and mechanical tests Sample preparati
24、on and conditioning ISO 2589, Leather Physical and mechanical tests Determination of thickness 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 bending force force exerted by the specimen on the measuring bar at a specified bending angle, bend
25、ing length and bending rate 3.2 bending angle angle at which the bending force is measured 3.3 bending length length around which the specimen is bent NOTE The bending length is the distance between the clamping device of the specimen and the bar onto which the force of the specimen is transferred.
26、3.4 bending rate rate of bending of the specimen NOTE The bending rate is expressed in degrees per sec (/s). 3.5 compression bending compression of the grain side or coating of the leather during bending BS EN ISO 14087:2011ISO 14087:2011(E) IULTCS/IUP 54:2011(E) 2 ISO 2011 All rights reserved3.6 ex
27、tension bending extension of the grain side or coating of the leather during bending 4 Principle The bending force is determined based on the bar method (two-point bending method). In this method, the specimen is clamped in a rotating fixture. During the rotation, the specimen exerts a force onto a
28、bar. The force acting at a specified bending angle is measured. 5 Apparatus 5.1 Device for determining the bending force according to the bar method (two-point bending method) comprising the following. 5.1.1 Clamping mechanism, in which the specimen shall be able to be clamped vertically. The clampi
29、ng jaws shall have a depth of (35 1) mm and a minimum width of at least 30 mm (see Figure 1). The clamping device shall enable parallel clamping with an even pressure distribution on the specimen. It shall move smoothly and allow tightening with a torque wrench. The clamping device shall allow for a
30、ffixing the specimen without it touching the bar in its initial position. Key 1a fixed clamping jaws 1b moving clamping jaws 2 aperture 6 mm 3 jaw width 30 mm 4 jaw depth (35 1) mm 5 pivot axis Figure 1 Clamping jaws 5.1.2 Means for rotating the clamping device about the pivot axis. The pivot axis i
31、s located exactly at the front edge of the fixed clamp (deviation of 0,1 mm) (see Figure 1). Rotation shall be possible within the range of 1 to 91 with a maximum deviation of 0,1. The rotational speed shall be able to be adjusted up to 10 /s with an accuracy of 0,1 /s. At maximum load, the maximum
32、deviation of the rotational speed allowed is 0,1 %. BS EN ISO 14087:2011ISO 14087:2011(E) IULTCS/IUP 54:2011(E) ISO 2011 All rights reserved 35.1.3 Means of measuring the bending force. The rotation of the specimen causes it to be pressed against a vertical metering bar. (See Figure 2.) The bar is c
33、onnected to a load cell that allows measurement of forces up to 10 N (optionally, 1 N for very flexible materials) with a minimum resolution of 0,1 % and a maximum deviation of 0,1 %. The bar design shall exhibit a sharp edge (R 0,05 0,01 mm) and a width of at least 30 mm. The weight of the bar shal
34、l not influence the measured value. The distance between the bar and the pivot point shall be adjustable in a range from 0,1 mm to 50 mm with an accuracy of 0,1 mm. At the start of the measurement, the specimen is moved towards the bar until contact is made and a defined preliminary force is reached
35、. This preliminary force shall be able to be adjusted with an accuracy of 1 mN. When the preliminary force is reached, the measurement shall start (angle 0 and force preliminary force setting). The evaluation unit shall ensure measurement of the force at one or more previously defined angles. These
36、angles shall not be identical to the maximum angle of rotation. The measuring apparatus shall ensure that all significant parameters (force, length, speed) can be checked, calibrated and restored. It is recommended that the measured data (raw data and parameter settings) are able to be electronicall
37、y archived. Key 1 load cell 2 vertical metering bar 3 bending length adjustable 4 free sample length 5 sample length 6 sample aRotating direction. Figure 2 Clamping jaws with specimen, load cell and bar with sharp edge NOTE An example of a commercial source for a suitable device is given in Annex A.
38、 5.2 Torque wrench, suitable for a range from 0,05 Nm to 0,2 Nm with an accuracy of 0,01 Nm. 5.3 Press knife, as specified in ISO 2419 for the corresponding specimen size. BS EN ISO 14087:2011ISO 14087:2011(E) IULTCS/IUP 54:2011(E) 4 ISO 2011 All rights reserved6 Sampling and sample preparation Samp
39、ling is conducted according to ISO 2418 if possible and conditioning according to ISO 2419. The dimensions of the specimens shall be taken from the relevant parameter sets (see 7.1). Other dimensions are permissible but shall be indicated in the test report. The sample is taken parallel with and per
40、pendicular to the backbone. Other sampling angles (e.g. diagonal) are also permissible and details shall be given in the test report. If the orientation of the backbone is not known, each specimen shall be taken in two directions running perpendicular to each other. At least three specimens shall be
41、 used in each direction. If both the compression and extension bending tests are to be conducted on the leather sample, an additional three specimens shall be used for each sampling direction. 7 Test procedure 7.1 Each specimen shall be tested only once and shall then be discarded. The specimen shal
42、l be carefully clamped into the test device such that the free-standing part of the specimen corresponds to the clamping length specified in Table 1. A torque wrench (5.2) with a setting of 0,08 Nm shall be used to tighten the clamping jaws. Then, the test shall be started with one of the specified
43、parameter sets specified in the table below. The measurement starts at 0 when the specified preliminary force is reached. The measured forces shall be recorded at the required bending angle. Both extension and compression bending of the grain/coated side is possible. For the extension bending test,
44、the leather specimen shall be inserted so that the bar will press on the grain/coated side. For the compression bending test, the leather specimen shall be inserted so that the bar will press on the flesh/back side. Three different sets of parameters can be used. If no set is specified, use set A as
45、 the standard set. Table 1 Parameter sets Parameter set A (standard) B C bending length (mm) 5 10 15 free clamping length (mm) 15 20 25 measurement in bending angle of () 60 60 60 bending up to an angle of () 63 63 63 bending rate (/s) 1,5 1,5 1,5 bending rate up to preliminary force (/s) 1,5 1,5 1,
46、5 dimensions of sample (width length) (mm) 30 50 30 55 30 60 preliminary force (mN) 3 3 3 Unless otherwise specified, calculate the mean value for all sampling directions (using all individual values). For measurements testing both bending parameters of the leather (compression and extension), mean
47、values for each bending parameter shall be calculated. The mean values shall be given in the test report. 7.2 Measure the thickness of the leather in accordance to ISO 2589. The same specimens used for the measurement of flexural properties can be used. In this case, thickness shall be measured afte
48、r the measurement of flexural properties. BS EN ISO 14087:2011ISO 14087:2011(E) IULTCS/IUP 54:2011(E) ISO 2011 All rights reserved 58 Test report The test report shall include the following: a) reference to this International Standard (i.e. ISO 14087); b) a description of the test specimen(s); c) sa
49、mpling angle; d) mean value of the thickness; e) parameter set used for measurement; f) indication of which side was measured (compression and/or extension); g) average of bending force in mN with three significant digits; h) any deviations from this International Standard. BS EN ISO 14087:2011ISO 14087:2011(E) IULTCS/IUP 54:2011(E) 6 ISO 2011 All rights reservedAnnex A (informative) Source of apparatus An example of a suitable product available commercially is given below. This informati
