1、raising standards worldwideNO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBSI Standards PublicationBS EN ISO 1974:2012Paper Determination oftearing resistance ElmendorfmethodBS EN ISO 1974:2012 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of
2、EN ISO 1974:2012.It supersedes BS EN 21974:1994 which is withdrawn.The UK participation in its preparation was entrusted to TechnicalCommittee PAI/11, Methods of test for paper, board and pulps.A list of organizations represented on this committee can beobtained on request to its secretary.This publ
3、ication does not purport to include all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2012. Published by BSI StandardsLimited 2012ISBN 978 0 580 70486 4ICS 85.060Compliance with a British Standard cannot confer immunity fro
4、mlegal obligations.This British Standard was published under the authority of theStandards Policy and Strategy Committee on 31 May 2012.Amendments issued since publicationDate Text affectedEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN ISO 1974 May 2012 ICS 85.060 Supersedes EN 21974:1994Engli
5、sh Version Paper - Determination of tearing resistance - Elmendorf method (ISO 1974:2012) Papier - Dtermination de la rsistance au dchirement - Mthode Elmendorf (ISO 1974:2012) Papier - Bestimmung des Durchreiwiderstandes - Elmendorf Methode (ISO 1974:2012) This European Standard was approved by CEN
6、 on 10 May 2012. CEN members 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
7、 be obtained on application 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 t
8、o the CEN-CENELEC Management 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, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Lux
9、embourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: Avenue Marnix 17, B-1000 Brussels 2012 CE
10、N All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN ISO 1974:2012: EBS EN ISO 1974:2012EN ISO 1974:2012 (E) 3 Foreword This document (EN ISO 1974:2012) has been prepared by Technical Committee ISO/TC 6 “Paper, board and pulps” in collabo
11、ration with Technical Committee CEN/TC 172 “Pulp, paper and board” the secretariat of which is held by DIN. 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 November 2012, and conflicting national
12、standards shall be withdrawn at the latest by November 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. This document supersedes
13、EN 21974:1994. According to the 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, France, Germany, Greece, Hungary, I
14、celand, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. Endorsement notice The text of ISO 1974:2012 has been approved by CEN as a EN ISO 1974:2012 without any modific
15、ation. BS EN ISO 1974:2012ISO 1974:2012(E) ISO 2012 All rights reserved iiiContents PageForeword iv1 Scope 12 Normative references . 13 Terms and definitions . 14 Principle . 15 Apparatus 26 Sampling 47 Conditioning . 48 Preparation of test pieces . 49 Adjustment and calibration of apparatus . 510 P
16、rocedure 511 Calculation and expression of results . 611.1 Tearing resistance . 611.2 Tear index 611.3 Coefficient of variation . 712 Test report . 7Annex A (normative) Adjustment and maintenance of Elmendorf-type tear testers 8Annex B (normative) Calibration of Elmendorf-type tear testers 10Annex C
17、 (informative) Precision .12Bibliography .14BS EN ISO 1974:2012ISO 1974:2012(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through IS
18、O 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 part in the work. ISO collaborates c
19、losely 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 to prepare International Standards. Dra
20、ft 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 possibility that some of the elements of this docum
21、ent may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights.ISO 1974 was prepared by Technical Committee ISO/TC 6, Paper, board and pulps, Subcommittee SC 2, Test methods and quality specifications for paper and board.This fourth edition c
22、ancels and replaces the third edition (ISO 1974:1990), which has been technically revised. The specification for the tester has been moved from Annex A to Clause 5 and is given in more general terms so that this International Standard is applicable to a wider range of designs. In addition, new preci
23、sion data have been inserted in Annex C.iv ISO 2012 All rights reservedBS EN ISO 1974:2012INTERNATIONAL STANDARD ISO 1974:2012(E)Paper Determination of tearing resistance Elmendorf method1 ScopeThis International Standard specifies a method for determining the (out-of-plane) tearing resistance of pa
24、per. It can also be used for boards having a low grammage if the tearing resistance is within the range of the instrument.This International Standard does not apply to corrugated fibreboard, but it may be applied to the components of such boards. It is not suitable for determining the cross-directio
25、n tearing resistance of highly directional paper (or board).2 Normative referencesThe 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 (in
26、cluding any amendments) applies.ISO 186, Paper and board Sampling to determine average qualityISO 187, Paper, board and pulps Standard atmosphere for conditioning and testing and procedure for monitoring the atmosphere and conditioning of samplesISO 536, Paper and board Determination of grammage3 Te
27、rms and definitionsFor the purposes of this document, the following terms and definitions apply.3.1tearing resistancemean force per sheet required to continue the tearing started by an initial cut in the test pieceNOTE 1 If the initial cut is in the machine direction, the result is given as the mach
28、ine-direction tearing resistance; similarly, if the initial cut is in the cross-direction, the result is given as the cross-direction tearing resistance.NOTE 2 The tearing resistance is expressed in millinewtons (mN).3.2tear indextearing resistance of the paper (or board) divided by its grammageNOTE
29、 The tear index is expressed in millinewton square metres per gram (mNm2/g).3.3test piecepack of four rectangular sheets of the same sizeNOTE The dimensions depend on the design of the apparatus clamp used (see Clause 8).4 PrincipleAn initial cut is made in a test piece (of four superimposed sheets)
30、, which is then torn out-of-plane through a given distance along one single tear line using a pendulum. The work done in tearing the test piece is measured as the loss in energy of the pendulum.The mean tearing force of a single sheet is calculated by dividing the work done by the distance torn and
31、the number of sheets in a test piece. ISO 2012 All rights reserved 1BS EN ISO 1974:2012ISO 1974:2012(E)aTearing force.Figure 1 Principle of the Elmendorf method5 Apparatus5.1 Elmendorf-type tear tester, of suitable capacity, consisting of the following parts.5.1.1 Stationary frame, mounted on a rigi
32、d base and provided with a levelling device. The frame shall be held stationary during the measurement by its mass or by attaching the tear tester to a stable stand.5.1.2 Pendulum, carried by the frame. The pendulum is formed, in principal, by a sector of a circle and is free to swing about a horizo
33、ntal axis on low-frictional bearings.To enable a wide range of tearing resistance to be measured, a set of interchangeable pendulums having different capacities (see Table 1), or one pendulum having interchangeable weights, may be used. The result shall fall within approximately 20 % to 80 % of the
34、maximum reading.Table 1 Recommended pendulum capacitiesCapacitymN2 0004 0008 00016 0002 ISO 2012 All rights reservedBS EN ISO 1974:2012ISO 1974:2012(E)Pendulums that have other capacities, e.g. 32 000 mN, may exist. High-capacity pendulums may be used for testing very strong papers such as asphalt p
35、aper.NOTE 1 High-capacity pendulums are, in many cases, used when more than one test piece, i.e. more than four sheets, are torn together. This is, however, not in compliance with this International Standard.The pendulums shall have an arrangement for attaching calibration weights.NOTE 2 The total w
36、ork done by the pendulum includes the work done in tearing the test piece and also the work done in lifting and bending the test piece and overcoming friction between the torn edges of the test piece. With some instruments, the total work done also includes overcoming frictional forces due to the te
37、st piece rubbing on the pendulum during the test. This is a major source of error on such apparatus, and apparatus on which this occurs is not considered suitable for testing in accordance with this International Standard. Instruments modified by a suitable cut-out to avoid this problem are availabl
38、e.5.1.3 Catch, which holds the pendulum when it is raised from its equilibrium position to the starting position and which can instantaneously be released.5.1.4 Two clamping jaws, one stationary jaw attached to the frame, and one movable jaw attached to the pendulum. The jaws shall be mounted in suc
39、h a way that the test piece does not touch the pendulum or the frame when bent due to the tearing force.With the pendulum in its raised position, the jaws shall be separated by a distance of (2,8 0,3) mm and so aligned that the test piece clamped in them lies in a vertical plane parallel to the axis
40、 of the pendulum. The clamping surface in each jaw shall be 25 mm 1 mm or 36 mm 1 mm wide and 15 mm 1 mm deep and the clamping surfaces shall be flat and parallel. The distance between the axis of the pendulum and the top edges of the jaws, which are in a horizontal line, shall be 102 73305,+mm. The
41、 line between the axis and the top edges of the jaws shall make an angle of (27,5 0,5) with the vertical.NOTE The asymmetric tolerance for the distance between the axis of the pendulum and the top edges of the jaws results from keeping a value consistent with the original Elmendorf, e.g. 102,7 mm, t
42、aking into account the different types of apparatus existing on the market while at the same time maintaining the value within the desired range.The jaws shall clamp the test piece with a force large enough to prevent the test piece from slipping during the test.5.1.5 Cutting knife (see Figure 2), i
43、f applicable, centred between the clamping jaws and mounted on the frame so that, when a test piece is clamped with the pendulum in the raised starting position, an initial cut can be made in the lower part of the test piece.The knife shall be adjusted so that the tearing length after cutting is (43
44、,0 0,5) mm when the lower edges of the test piece rest against the bottom of the jaws.5.1.6 Means for registering the maximum arc scale reading A in Equation (2) through which the pendulum swings when released, e.g. a pointer assembly, or a means for direct reading of the tearing resistance reading
45、F in Equation (1), e.g. transducer outputs.5.2 Device for preparing the test piece, e.g. a suitable die, guillotine or template and knife, if applicable, with the required dimensions (see Figure 2). ISO 2012 All rights reserved 3BS EN ISO 1974:2012ISO 1974:2012(E)Dimensions in millimetresKeyA test p
46、ieceB knifeC clampD distance between clampsFigure 2 Important dimensions of the test piece, the knife and the clamps6 SamplingIf the tests are made to evaluate a lot, select the sample in accordance with ISO 186. If the tests are made on another type of sample, make sure that the test specimens take
47、n are representative of the sample received.7 ConditioningCondition the sample as specified in ISO 187. Keep the sample in the prescribed atmosphere throughout the test.This test, like other mechanical tests, is very sensitive to changes in moisture content of the test piece. Handle the test pieces
48、carefully and never touch with a bare hand the region of the test piece to be tested. Keep the test pieces away from moisture, heat and other influences that may change their moisture content.8 Preparation of test piecesPrepare the test pieces in the same conditioning atmosphere used to condition th
49、e samples. If the tear index is to be calculated, determine the grammage of the sample in accordance with ISO 536.The sample shall be free from folds, creases or other visible defects in the area from which the test piece is cut and the test piece shall not include any part of the sample that is less than 15 mm from the edge of the sheet or reel. If watermarks are present, this shall be stated in the test report.4 ISO 2012 All rights reservedBS EN ISO 1974:2012ISO 1974:2012(E)Identify the two sides of the sample in
