1、March 2012 Translation by DIN-Sprachendienst.English price group 7No part of this translation may be reproduced without prior permission ofDIN Deutsches Institut fr Normung e. V., Berlin. Beuth Verlag GmbH, 10772 Berlin, Germany,has the exclusive right of sale for German Standards (DIN-Normen).ICS 5
2、9.140.30!$zC8“1873221www.din.deDDIN EN ISO 14087Leather Physical and mechanical tests Determination of bending force (ISO 14087:2011)English translation of DIN EN ISO 14087:2012-03Leder Physikalische und mechanische Prfungen Bestimmung der Biegekraft (ISO 14087:2011)Englische bersetzung von DIN EN I
3、SO 14087:2012-03Cuir Essais physiques et mcaniques Dtermination de la force de flexion (ISO 14087:2011)Traduction anglaise de DIN EN ISO 14087:2012-03www.beuth.deDocument comprises pagesIn case of doubt, the German-language original shall be considered authoritative.1103.12 DIN EN ISO 14087:2012-03
4、2 A comma is used as the decimal marker. National foreword This standard has been prepared by Technical Committee CEN/TC 289 “Leather” (Secretariat: UNI, Italy) in collaboration with IULTCS, the International Union of Leather Technologists and Chemists Societies. The responsible German body involved
5、 in its preparation was the Normenausschuss Materialprfung (Materials Testing Standards Committee), Working Committee NA 062-05-51 AA Anforderungen und physika-lische Prfverfahren fr Leder und seine Ausgangsprodukte. The DIN Standards corresponding to the International Standards referred to in this
6、document are as follows: ISO 2418 DIN EN ISO 2418 ISO 2419 DIN EN ISO 2419 ISO 2589 DIN EN ISO 2589 National Annex NA (informative) Bibliography DIN EN ISO 2418, Leather Chemical, physical and mechanical and fastness tests Sampling location DIN EN ISO 2419, Leather Physical and mechanical tests Samp
7、le preparation and conditioning DIN EN ISO 2589, Leather Physical and mechanical tests Determination of thickness EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 14087 December 2011 ICS 59.140.30 English Version Leather - Physical and mechanical tests - Determination of bending force (ISO 1
8、4087:2011) 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 bound to comply with the
9、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 the CEN-CENELEC Management
10、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 Centre has the same status as
11、 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, Norway, Poland, Portugal, Rom
12、ania, 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 and by any means reserved
13、 worldwide for CEN national Members. Ref. No. EN ISO 14087:2011: EContents DIN EN ISO 14087:2012-03 EN ISO 14087:2011 (E) 2 Page Foreword 3 1 Scope 4 2 Normative references 4 3 Terms and definitions .4 4 Principle 5 5 Apparatus .5 6 Sampling and sample preparation .7 7 Test procedure .7 8 Test repor
14、t 8 Annex A (informative) Source of apparatus .9 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 with IULTCS International Union of Leather Technologists and Chemists Societies0148”. T
15、his 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 at the latest by June 2012. Attention is drawn to the possibility that some of the e
16、lements 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 national standards organizations of the following countries are bound to implement this
17、 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, Switzerland
18、and the United Kingdom. “DIN EN ISO 14087:2012-03 EN ISO 14087:2011 (E) 3 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 documen
19、t. 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, physical and mechanical and fastness tests Sampling location ISO 2419, Leather Physical and mechanical tests
20、Sample preparation 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 ben
21、ding angle, bending 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
22、is transferred. 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 DIN EN ISO 14087:2012-03 EN ISO 14087:2011 (E) 4 3.6 extension bending extension
23、 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 bar. The force acting at
24、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 clamping jaws shall have a dept
25、h 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 affixing the specimen with
26、out 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 is located exactly at the
27、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 deviation of the rotation
28、al speed allowed is 0,1 %. DIN EN ISO 14087:2012-03 EN ISO 14087:2011 (E) 5 5.1.3 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 connected to a load cell that allows measurement of forces up to 10
29、 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 shall not influence the measured value. The distance between the bar a
30、nd 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. This preliminary force shall be able to be adjusted with an accu
31、racy 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 angles shall not be identical to the maximum angle of rotation. Th
32、e 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 electronically archived. Key 1 load cell 2 vertical metering bar 3 bending leng
33、th 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. 5.2 Torque wrench, suitable for a range from 0,05 Nm to 0,2 Nm wi
34、th an accuracy of 0,01 Nm. 5.3 Press knife, as specified in ISO 2419 for the corresponding specimen size. DIN EN ISO 14087:2012-03 EN ISO 14087:2011 (E) 6 6 Sampling and sample preparation Sampling is conducted according to ISO 2418 if possible and conditioning according to ISO 2419. The dimensions
35、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 perpendicular to the backbone. Other sampling angles (e.g. diagonal) are also permissible and details shall be
36、 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 used in each direction. If both the compression and extension bending tests are to be conducted on the lea
37、ther 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 shall be carefully clamped into the test device such that the free-standing part of the specimen corresponds to
38、 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 parameter sets specified in the table below. The measurement starts at 0 when the specified preliminary for
39、ce 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, the leather specimen shall be inserted so that the bar will press on the grain/coated side. For the compres
40、sion 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 the standard set. Table 1 Parameter sets Parameter set A (standard) B C bending length (mm) 5 10 15 free c
41、lamping 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 1,5 dimensions of sample (width length) (mm) 30 50 30 55 30 60 preliminary force (mN) 3 3 3 Unless otherwise
42、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 values for each bending parameter shall be calculated. The mean values shall be given in the test report. 7
43、.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 after the measurement of flexural properties. DIN EN ISO 14087:2012-03 EN ISO 14087:2011 (E) 7 8 Test report Th
44、e 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) sampling angle; d) mean value of the thickness; e) parameter set used for measurement; f) indication of which side was measured (compression and/or ex
45、tension); g) average of bending force in mN with three significant digits; h) any deviations from this International Standard. DIN EN ISO 14087:2012-03 EN ISO 14087:2011 (E) 8 Annex A (informative) Source of apparatus An example of a suitable product available commercially is given below. This infor
46、mation is given for the convenience of users of this International Standard and does not constitute an endorsement by ISO of their product. A suitable apparatus is manufactured for example by FRANK-PTI GmbH, Auf der Aue 1, 69488 Birkenau, Germany, www.frank-. DIN EN ISO 14087:2012-03 EN ISO 14087:2011 (E) 9
