1、BS EN ISO 2420:2017Leather Physical andmechanical tests Determination of apparentdensity and mass per unit area(ISO 2420:2017)BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06BS EN ISO 2420:2017 BRITISH STANDARDNational forewordThis British Standard is the UK implemen
2、tation of EN ISO 2420:2017.It supersedes BS EN ISO 2420:2002 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee TCI/69, Footwear, leather and coated fabrics.A list of organizations represented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.
3、This publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application. The British Standards Institution 2017.Published by BSI Standards Limited 2017ISBN 978 0 580 86627 2 ICS 59.140.30 Compliance with a British Standard cannot con
4、fer immunity from legal obligations.This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2017.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 2420 Febru
5、ary 2017 ICS 59.140.30 Supersedes EN ISO 2420:2002English Version Leather - Physical and mechanical tests - Determination of apparent density and mass per unit area (ISO 2420:2017)Cuir - Essais physiques et mcaniques - Dtermination de la masse volumique apparente et de la masse surfacique (ISO 2420:
6、2017) Leder - Physikalische und mechanische Prfungen - Bestimmung der Rohdichte und der flchenbezogenen Masse (ISO 2420:2017) This European Standard was approved by CEN on 21 December 2016. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for g
7、iving 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 Centre or to any CEN member. This European Standard exists in three o
8、fficial 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 the official versions. CEN members are the national standards bodies
9、 of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Sloven
10、ia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2017 CEN All rights of exploitation in any form and by any means reserved w
11、orldwide for CEN national Members. Ref. No. EN ISO 2420:2017 EBS EN ISO 2420:2017EN ISO 2420:2017 (E) 3 European foreword This document (EN ISO 2420:2017) has been prepared by Technical Committee IULTCS “International Union of Leather Technologists and Chemists Societies“ in collaboration with Techn
12、ical Committee CEN/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 an identical text or by endorsement, at the latest by August 2017, and conflicting national standards shall be withdrawn at t
13、he latest by August 2017. 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. This document supersedes EN ISO 2420:2002. According to the
14、CEN-CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hun
15、gary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 2420:2017 has been approved by CEN as EN ISO 2420:2017 withou
16、t any modification. BS EN ISO 2420:2017ISO 2420:2017(E)IULTCS/IUP 5:2017(E)Foreword iv1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 15 Apparatus . 16 Sampling and sample preparation 27 Procedure. 27.1 Test conditions 27.2 Measurement of thickness 27.3 Measurement of dimen
17、sions . 27.4 Measurement of mass . 38 Expression of results 38.1 Apparent density . 38.2 Mass per unit area 49 Test report . 4 ISO 2017 All rights reserved iiiContents PageBS EN ISO 2420:2017ISO 2420:2017(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of
18、 national 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. Int
19、ernational 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.The procedures used to develop this document and those in
20、tended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular 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 w
21、ww .iso .org/ directives).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. Details of any patent rights identified during the development of the docum
22、ent will be in the Introduction and/or on the ISO list of patent declarations received (see www .iso .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 an
23、d expressions related to conformity assessment, as well as information about ISOs adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.ISO 2420 was prepared by the Physical Test Commission of the
24、 International Union of Leather Technologists and Chemists Societies (IUP Commission, IULTCS) in collaboration with the European 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 coopera
25、tion between ISO and CEN (Vienna Agreement).It is based on IUP 5 originally published in J. Soc. Leather Trades Chemists, 42, p. 388, (1958), and declared an official method of the IULTCS in 1959. An updated version was published in J. Soc. Leather Tech. Chem., 82, p. 227, (1998) and a further revis
26、ion was published in J. Soc. Leather Tech. Chem. 84. p. 313, (2000) and reconfirmed as an official method 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 Com
27、missions, 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 of test methods for leather.This third edition cancels and replaces the second edition (ISO 2420:2002), whi
28、ch has been technically revised with the following changes: the mass per unit area has been included; the option to use square test pieces has been included.IULTCS/IUP 5:2017(E)iv ISO 2017 All rights reservedBS EN ISO 2420:2017INTERNATIONAL STANDARDISO 2420:2017(E)IULTCS/IUP 5:2017(E)Leather Physica
29、l and mechanical tests Determination of apparent density and mass per unit area1 ScopeThis document specifies a method for determining the apparent density and the mass per unit area of leather. It is applicable to all leathers.2 Normative referencesThe following documents are referred to in the tex
30、t in such a way that some or all of their content constitutes requirements 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, physical and mechani
31、cal and fastness tests Sampling locationISO 2419, Leather Physical and mechanical tests Sample preparation and conditioningISO 2589, Leather Physical and mechanical tests Determination of thicknessEN 15987, Leather Terminology Key definitions for the leather trade3 Terms and definitionsFor the purpo
32、ses of this document, the terms and definitions given in EN 15987 apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: IEC Electropedia: available at h t t p :/ www .electropedia .org/ ISO Online browsing platform: available at h t t p :/ www .is
33、o .org/ obp4 PrincipleThe volume of a test piece is calculated from the area and thickness, treating the test piece as a right-angled circular cylinder or cuboid with a square base. The apparent density is obtained by dividing the mass by the volume. The mass per unit area is obtained by dividing th
34、e mass by the area.5 Apparatus5.1 Press knife, conforming to ISO 2419, the inner wall of which is a circle, approximately 70 mm in diameter, or square, approximately (100 100) mm.5.2 Thickness gauge, as specified in ISO 2589.5.3 Balance, reading to 0,001 g.5.4 Vernier callipers, reading to 0,01 mm.
35、ISO 2017 All rights reserved 1BS EN ISO 2420:2017ISO 2420:2017(E)6 Sampling and sample preparationSample in accordance with ISO 2418. From the sample, cut three test pieces by applying the press knife (5.1) to the grain surface and condition them in accordance with ISO 2419.If there is a requirement
36、 for more than two hides or skins to be tested in one batch, then only one test piece needs to be taken from each hide or skin, provided that the overall total is not less than three test pieces.7 Procedure7.1 Test conditionsCarry out all operations in a standard atmosphere as specified in ISO 2419.
37、7.2 Measurement of thicknessMeasure the thickness of each test piece in accordance with ISO 2589. Measure the thickness, in millimetres, at three points forming the corners of an equilateral triangle, with each situated approximately 20 mm from the centre of the test piece. Measure the thickness at
38、the centre of the test piece. Take the arithmetic mean of the four results as the thickness of the test piece, t.NOTE The centre of the test piece and the other points for measurement are estimated by eye.7.3 Measurement of dimensionsFor circular test pieces, measure the diameter using Vernier calli
39、pers (5.4) to the nearest 0,05 mm in two directions at right angles to each other on the grain surface and two directions at right angles on the flesh surface. Take the arithmetic mean of the four results as the mean diameter of the test piece, d. Reject any test piece where the diameters on either
40、the grain surface or the flesh surface differ by more than 0,5 mm.For square test pieces, measure the distances AC and BD, where A, B, C and D are the midpoints of each side to within 0,5 mm, using Vernier callipers (5.4) to the nearest 0,05 mm as shown in Figure 1. Measure the distances on both the
41、 grain surface and on the flesh surface. Take the arithmetic mean of the results for the two results of AC, a, and BD, b, respectively. Reject any test piece where the distance measured on the grain surface differs more than 0,5 mm from the distance measured on the flesh surface.Figure 1 Measurement
42、 of distances on square test piecesIULTCS/IUP 5:2017(E)2 ISO 2017 All rights reservedBS EN ISO 2420:2017ISO 2420:2017(E)7.4 Measurement of massMeasure the mass of the test piece, m, in grams to the nearest 0,001 g.8 Expression of results8.1 Apparent densityFor cylindrical test pieces, the apparent d
43、ensity, Da, in kilograms per cubic metre shall be calculated using Formula (1):Dmtda=1 273 1062,(1)wheret is the mean thickness of the test piece in millimetres (as obtained in 7.2);d is the mean diameter of the test piece in millimetres (as obtained in 7.3);m is the mass of the test piece in grams
44、(as obtained in 7.4).NOTE 1 Formula (1) assumes that the sample is a circular cylinder whose volume, V, in cubic millimetres is given by:Vdt=pi24which is simplified to dt21 273,The factor 1,273 continues through to the final calculation.For cuboid test pieces with a square base, the apparent density
45、, Da, in kilograms per cubic metre shall be calculated using Formula (2):Dmtaba=106(2)wheret is the mean thickness of the test piece in millimetres (as obtained in 7.2);a is the mean distance AC of the test piece in millimetres (as obtained in 7.3);b is the mean distance BD of the test piece in mill
46、imetres (as obtained in 7.3);m is the mass of the test piece in grams (as obtained in 7.4).NOTE 2 The apparent density of leather is often expressed in g/cm3. If it is necessary to express it in these units, then 1 g/cm3= 1 000 kg/m3.IULTCS/IUP 5:2017(E) ISO 2017 All rights reserved 3BS EN ISO 2420:
47、2017ISO 2420:2017(E)8.2 Mass per unit areaFor cylindrical test pieces, the mass per unit area, ma, in grams per square metre shall be calculated using Formula (3):mmda=1 273 1062,(3)whered is the mean diameter of the test piece in millimetres (as obtained in 7.3);m is the mass of the test piece in g
48、rams (as obtained in 7.4).For cuboid test pieces with a square base, the mass per unit area, ma, in grams per square metre shall be calculated using Formula (4):mmaba=106(4)wherea is the mean distance AC of the test piece in millimetres (as obtained in 7.3);b is the mean distance BD of the test piec
49、e in millimetres (as obtained in 7.3);m is the mass of the test piece in grams (as obtained in 7.4).9 Test reportThe test report shall include at least the following:a) a reference to this document, i.e. ISO 2420:2017;b) the mean apparent density, Da, in kilograms per cubic metre expressed to three significant figures;c) the mean mass per unit area, ma, in grams per square metre expressed to three significant figures;d) the standard atmosphere used for conditioning and testing as given in ISO 2419;e) any deviatio
