1、BSI Standards PublicationBS ISO 34-1:2015Rubber, vulcanized orthermoplastic Determinationof tear strengthPart 1: Trouser, angle and crescent testpiecesBS ISO 34-1:2015 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of ISO 34-1:2015. It supersedes BS ISO 34-1:2010 whi
2、ch is withdrawn.The UK participation in its preparation was entrusted to Technical Committee PRI/22, Physical testing of rubber.A list of organizations represented on this committee can be obtained on request to its secretary.This publication does not purport to include all the necessary provisions
3、of a contract. Users are responsible for its correct application. The British Standards Institution 2015.Published by BSI Standards Limited 2015ISBN 978 0 580 87263 1ICS 83.060Compliance with a British Standard cannot confer immunity from legal obligations.This British Standard was published under t
4、he authority of the Standards Policy and Strategy Committee on 30 June 2015.Amendments/corrigenda issued since publicationDate T e x t a f f e c t e dBS ISO 34-1:2015 ISO 2015Rubber, vulcanized or thermoplastic Determination of tear strength Part 1: Trouser, angle and crescent test piecesCaoutchouc
5、vulcanis ou thermoplastique Dtermination de la rsistance au dchirement Partie 1: prouvettes pantalon, angulaire et croissantINTERNATIONAL STANDARDISO34-1Fourth edition2015-06-01Reference numberISO 34-1:2015(E)BS ISO 34-1:2015ISO 34-1:2015(E)ii ISO 2015 All rights reservedCOPYRIGHT PROTECTED DOCUMENT
6、 ISO 2015, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written perm
7、ission. Permission can be requested from either ISO at the address below or ISOs member body in the country of the requester.ISO copyright officeCh. de Blandonnet 8 CP 401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 34-1:2015ISO 34-1:
8、2015(E)Foreword iv1 Scope . 12 Normative references 23 Terms and definitions . 24 Principle 25 Apparatus . 36 Calibration 57 Test piece 68 Number of test pieces 69 Temperature of test . 610 Procedure. 711 Expression of results 712 Test report . 7Annex A (informative) Precision results from an interl
9、aboratory test programme . 9Annex B (normative) Calibration schedule 13Bibliography .15 ISO 2015 All rights reserved iiiContents PageBS ISO 34-1:2015ISO 34-1:2015(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bod
10、ies). 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. International organizations, governmental and
11、 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 intended for its further maintenance are des
12、cribed 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 www.iso.org/directives). Attention is drawn
13、 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 document will be in the Introduction and/or on th
14、e 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 and expressions related to conformity assessment
15、, as well as information about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis.This fo
16、urth edition cancels and replaces the third edition (ISO 34-1:2010), which has been technically revised. Precision results from an interlaboratory have been updated as Annex A.ISO 34 consists of the following parts, under the general title Rubber, vulcanized or thermoplastic Determination of tear st
17、rength: Part 1: Trouser, angle and crescent test pieces Part 2: Small (Delft) test piecesiv ISO 2015 All rights reservedBS ISO 34-1:2015Rubber, vulcanized or thermoplastic Determination of tear strength Part 1: Trouser, angle and crescent test piecesWARNING 1 Persons using this part of ISO 34 should
18、 be familiar with normal laboratory practice. This part of ISO 34 does not purport to address all of the safety problems, if any, associated with its use. It is the responsibility of the user to establish appropriate safety and health practices and to ensure compliance with any national regulatory c
19、onditions.WARNING 2 Certain procedures specified in this part of ISO 34 might involve the use or generation of substances, or the generation of waste, that could constitute a local environmental hazard. Reference should be made to appropriate documentation on safe handling and disposal after use.1 S
20、copeThis part of ISO 34 specifies three test methods for the determination of the tear strength of vulcanized or thermoplastic rubber, namely the following: method A, using a trouser test piece; method B, using an angle test piece, with or without a nick of specified depth; method C, using a crescen
21、t test piece with a nick.The value of tear strength obtained depends on the shape of the test piece, speed of stretching, and temperature of test. It can also be susceptible to grain effects in rubber.Method A: Using a trouser test pieceMethod A, using the trouser test piece, is preferred because it
22、 is not sensitive to the length of the cut, unlike the other two test pieces in which the nick has to be very closely controlled. In addition, the results obtained are more easily related to the fundamental tear properties of the material and are less sensitive to modulus effects (provided that the
23、leg extension is negligible) and the rate of propagation of the tear is directly related to the rate of grip separation. With some rubbers, the propagation of tear is not smooth (knotty tear), and analysis of results can be difficult.3Method B, procedure (a): Using an angle test piece without nickTh
24、is test is a combination of tear initiation and propagation. Stress is built up at the point of the angle until it is sufficient to initiate a tear and then further stresses propagate this tear. However, it is only possible to measure the overall force required to rupture the test piece, and, theref
25、ore, the force cannot be resolved in two components producing initiation and propagation.4Method B, procedure (b): Using an angle test piece with nickThis test measures the force required to propagate a nick already produced in the test piece. The rate of propagation is not directly related to the j
26、aw speed.5Method C: Using a crescent test pieceINTERNATIONAL STANDARD ISO 34-1:2015(E) ISO 2015 All rights reserved 1BS ISO 34-1:2015ISO 34-1:2015(E)This test also measures the force required to propagate a nick already produced in the test piece, and the rate of propagation is not related to the ja
27、w speed.NOTE A separate method for the determination of the tear strength of small test pieces of rubber (Delft test pieces) is specified in ISO 34-2.12 Normative referencesThe following documents, in whole or in part, are normatively referenced in this document and are indispensable for its applica
28、tion. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.ISO 5893, Rubber and plastics test equipment Tensile, flexural and compression types (constant rate of traverse) SpecificationISO 6133,
29、 Rubber and plastics Analysis of multi-peak traces obtained in determinations of tear strength and adhesion strengthISO 18899:2013, Rubber Guide to the calibration of test equipmentISO 23529, Rubber General procedures for preparing and conditioning test pieces for physical test methods3 Terms and de
30、finitionsFor the purposes of this document, the following terms and definitions apply.3.1trouser tear strengthmedian force required to propagate a cut in a specified trouser-shaped test piece by tearing, divided by the thickness of the test piece, the force acting in a direction substantially in the
31、 plane of the cutNote 1 to entry: The median force is calculated in accordance with ISO 6133.3.2unnicked angle tear strengthmaximum force required to rupture a specified angle-shaped test piece, divided by the thickness of the test piece, the force acting in a direction substantially along the lengt
32、h of the test piece3.3nicked angle tear strengthcrescent tear strengthmaximum force required to cause a nick cut in a specified angle- or crescent-shaped test piece to extend by tearing of the rubber, divided by the thickness of the test piece, the force acting in a direction substantially normal to
33、 the plane of the nick4 PrincipleThe test consists in measuring the force required to tear a specified test piece, in continuation of the cut or nick already produced in the test piece or, in the case of method B, procedure (a), completely across the width of the test piece.The tearing force is appl
34、ied by means of a tensile testing machine, operated without interruption at a constant rate of traverse until the test piece breaks. Dependent upon the method employed, the maximum or median force achieved is used to calculate the tear strength.No correlation between data obtained by the alternative
35、 test pieces is implied.2 ISO 2015 All rights reservedBS ISO 34-1:2015ISO 34-1:2015(E)5 Apparatus5.1 Dies5.1.1 The die used for cutting trouser test pieces shall have the dimensions shown in Figure 1.5.1.2 The die used for cutting angle test pieces shall have the dimensions shown in Figure 2.5.1.3 T
36、he die used for cutting crescent test pieces shall have the dimensions shown in Figure 3.5.1.4 The cutting edges of the dies shall be kept sharp and free from ragged edges. Care shall be taken that the cutting edges are perpendicular to the other surfaces of the die and have a minimum of concavity.5
37、.2 Nick cutterA sharp razor blade or a sharp knife free from ragged edges shall be used for producing a cut or a nick in the test piece.The apparatus for introducing the nick required for the nicked angle or crescent test piece shall be as follows.Means shall be provided for clamping the test piece
38、firmly, especially in the region where the nick is to be introduced. The cutting tool, consisting of a razor blade or similar blade, shall be clamped in a plane perpendicular to the major axis of the test piece, and positioned so as to introduce the nick in the appropriate place. The blade clamping
39、device shall permit no lateral movement and shall be fitted in guides to enable the blade to be moved across the test piece with its edge remaining perpendicular to the plane of the test piece. Alternatively, the blade shall be fixed and the test piece arranged to move in an analogous manner. Means
40、shall be provided for fine adjustment of the depth of the nick. The adjustment of the position of the blade holder or clamped test piece shall be determined for each blade by cutting one or two preliminary nicks and measuring these with the aid of a microscope. The blade shall be wetted with water o
41、r soap solution prior to nicking.NOTE A suitable apparatus for nicking tear test pieces has been described in detail in the literature.6To check that the depth of the nick is within the specified limits (see 7.4), any suitable means may be used, e.g. an optical projection apparatus. A convenient arr
42、angement is a microscope giving at least 10 magnification fitted with a travelling stage suitably illuminated. The eyepiece is fitted with a graticule or crosswire by which to record the travel of the stage and test piece through a distance equal to the depth of the nick. The travel of the stage is
43、calibrated with a stage micrometer.Alternatively, a travelling microscope may be used.The apparatus shall have an accuracy of measurement of 0,05 mm.5.3 Testing machineThe machine shall conform to the requirements of ISO 5893, to an accuracy corresponding to class 1.It shall be capable of registerin
44、g the applied forces within 1 % during the test while maintaining the specified constant rate of separation of the jaws of 100 mm/min 10 mm/min for the trouser test piece and 500 mm/min 50 mm/min for the angle and crescent test pieces. A low-inertia machine having autographic force-recording facilit
45、ies is essential when using the trouser test piece.5.4 GripsThe machine shall be provided with a type of grip which tightens automatically as the tension increases and exerts a uniform pressure across the widened end of the test piece. Each grip shall incorporate a means for positioning so that the
46、test pieces are inserted symmetrically and in axial alignment with the direction of the pull. The depth of insertion shall be such that the test piece is adequately gripped, ISO 2015 All rights reserved 3BS ISO 34-1:2015ISO 34-1:2015(E)within the parallel-sides portion, when testing angle and cresce
47、nt test pieces. Trouser test pieces shall be inserted in the grips in accordance with Figure 4.Dimensions in millimetresKey1 location of cutFigure 1 Trouser test piece dieDimensions in millimetresKey1 location of nick for method B, procedure (b)Figure 2 Angle test piece die4 ISO 2015 All rights rese
48、rvedBS ISO 34-1:2015ISO 34-1:2015(E)Dimensions in millimetresKey1 location of nickFigure 3 Crescent test piece dieFigure 4 Positioning of trouser test piece in testing machine6 CalibrationThe test apparatus shall be calibrated in accordance with the schedule given in Annex B. ISO 2015 All rights res
49、erved 5BS ISO 34-1:2015ISO 34-1:2015(E)7 Test piece7.1 Test pieces shall be cut from rubber sheet of uniform thickness. Preferably, the sheet shall have a thickness of 2,0 mm 0,2 mm; however, it is recognized that, when sheets are prepared from finished products, this thickness cannot always be achieved.Sheets may be moulded or prepared from products by cutting or buffing.The requirements of ISO 23529 shall apply to the time interval between forming or preparation of the sheet and cutting of test
