1、Rubber, vulcanized Determination of stress in tension upon heatingBS ISO 12493:2017BSI Standards PublicationWB11885_BSI_StandardCovs_2013_AW.indd 1 15/05/2013 15:06 ISO 2017Rubber, vulcanized Determination of stress in tension upon heatingCaoutchouc vulcanis Dtermination de la contrainte en traction
2、 lors du chauffageINTERNATIONAL STANDARDISO12493Second edition2017-07Reference numberISO 12493:2017(E)National forewordThis British Standard is the UK implementation of ISO 12493:2017. It supersedes BS ISO 12493:2011, which is withdrawn.The UK participation in its preparation was entrusted to Techni
3、cal Committee PRI/22, Testing and analysis 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 of a contract. Users are responsible for its correct application. The Briti
4、sh Standards Institution 2017 Published by BSI Standards Limited 2017ISBN 978 0 580 97194 5ICS 83.060Compliance with a British Standard cannot confer immunity from legal obligations. This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 August 2
5、017.Amendments/corrigenda issued since publicationDate Text affectedBRITISH STANDARDBS ISO 12493:2017 ISO 2017Rubber, vulcanized Determination of stress in tension upon heatingCaoutchouc vulcanis Dtermination de la contrainte en traction lors du chauffageINTERNATIONAL STANDARDISO12493Second edition2
6、017-07Reference numberISO 12493:2017(E)BS ISO 12493:2017ISO 12493:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form or b
7、y any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior written permission. 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
8、401CH-1214 Vernier, Geneva, SwitzerlandTel. +41 22 749 01 11Fax +41 22 749 09 47copyrightiso.orgwww.iso.orgBS ISO 12493:2017ISO 12493:2017(E)ii ISO 2017 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2017, Published in SwitzerlandAll rights reserved. Unless otherwise specified, no part of this
9、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 permission. Permission can be requested from either ISO at the address below or ISOs member body in the
10、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.orgISO 12493:2017(E)Foreword ivIntroduction v1 Scope . 12 Normative references 13 Terms and definitions . 14 Principle 25 Appara
11、tus . 25.1 Thermal-stress testing machine 25.2 Temperature-controlled chamber 35.3 Thickness- and width-measuring devices . 36 Calibration 37 Test piece 47.1 Dimensions . 47.2 Number of test pieces . 47.3 Time lapse between moulding and testing . 47.4 Conditioning 48 Test conditions . 48.1 Temperatu
12、re 48.2 Pre-strain . 59 Procedure. 510 Expression of results 511 Precision . 712 Test report . 7Annex A (normative) Calibration schedule . 9Bibliography .11 ISO 2017 All rights reserved iiiContents PageBS ISO 12493:2017ISO 12493:2017(E)ForewordISO (the International Organization for Standardization)
13、 is a worldwide federation of 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 repre
14、sented on that committee. International 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 devel
15、op this document and those intended 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/
16、IEC Directives, Part 2 (see www .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
17、 the development of the document 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 vol
18、untary nature of standards, the meaning of ISO specific terms and 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 .h
19、tml.This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis.This second edition cancels and replaces the first edition (ISO 12493:2011), of which it constitutes a minor revision to update the normative references in Clause 2.iv
20、 ISO 2017 All rights reservedBS ISO 12493:2017ISO 12493:2017(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 ISO technical comm
21、ittees. 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 closely with the
22、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 described in the ISO/IEC Directives, Part 1. In particular the different approval criteria needed for the
23、 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 to the possibility that some of the elements of this document may be the subject of patent rights.
24、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 the ISO list of patent declarations received (see www .iso .org/ patents).Any trade name used in this
25、document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISOs adherence to the World Trad
26、e Organization (WTO) principles in the Technical Barriers to Trade (TBT) see the following URL: www .iso .org/ iso/ foreword .html.This document was prepared by Technical Committee ISO/TC 45, Rubber and rubber products, Subcommittee SC 2, Testing and analysis.This second edition cancels and replaces
27、 the first edition (ISO 12493:2011), of which it constitutes a minor revision to update the normative references in Clause 2.iv ISO 2017 All rights reserved ISO 12493:2017(E)IntroductionVulcanized rubber held under a constant stress will contract as the test temperature is raised, while a test piece
28、 held under a constant strain will develop an increased stress. These are features of the Gough-Joule effect in rubber and, unless they are taken into account at the design stage, any resulting changes in forces and dimensions can affect the performance of some products, such as rotary seals, used a
29、t high temperatures and high strains (see Reference 1).This document describes a test method for the determination of the change in tensile stress that results from an increase in test temperature. ISO 2017 All rights reserved vBS ISO 12493:2017BS ISO 12493:2017Rubber, vulcanized Determination of st
30、ress in tension upon heatingWARNING 1 Persons using this document should be familiar with normal laboratory practice. This document 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
31、 practices and to ensure compliance with any national regulatory conditions.WARNING 2 Certain procedures specified in this document 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 appropria
32、te documentation on safe handling and disposal after use.1 ScopeThis document specifies a method for measuring the stress in tension which is developed in vulcanized rubber when it is heated (thermal stress). The thermal stress is measured for various pre-strain and temperature conditions as a funct
33、ion of time.2 Normative referencesThe following documents are referred to in the text 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
34、 (including any amendments) applies.ISO 5893, Rubber and plastics test equipment Tensile, flexural and compression types (constant rate of traverse) SpecificationISO 18899:2013, Rubber Guide to the calibration of test equipmentISO 23529, Rubber General procedures for preparing and conditioning test
35、pieces for physical test methods3 Terms and definitionsFor the purposes of this document, the following terms and definitions apply.ISO and IEC maintain terminological databases for use in standardization at the following addresses: ISO Online browsing platform: available at h t t p :/ www .iso .org
36、/ obp IEC Electropedia: available at h t t p :/ www .electropedia .org/ 3.1thermal stressTforce per initial unit area which is developed in the test piece upon heatingNote 1 to entry: It is expressed in N/m2or Pa.3.2maximum thermal stressmax. Tpeak value of the thermal stress recorded during the tes
37、tINTERNATIONAL STANDARD ISO 12493:2017(E) ISO 2017 All rights reserved 1BS ISO 12493:2017ISO 12493:2017(E)3.3thermal stress after a specified timeT,tstress induced in the test piece upon heating for a specified time t3.4pre-strainelongation to which the test piece is subjected at the beginning of th
38、e testNote 1 to entry: It is expressed as:pre-strainfii=lllwhereliis the initial length;lfis the length after elongation.3.5pre-stressforce per initial unit area which results from the pre-strainNote 1 to entry: It is expressed in N/m2or Pa.4 PrincipleA test piece is held at a constant pre-strain in
39、 a tensile mode at standard laboratory temperature. When the pre-stress resulting from the given pre-strain has reached an apparent equilibrium value, the temperature of the test piece is increased. The thermal stress developed at the elevated temperature is measured for various pre-strain condition
40、s as a function of time.5 Apparatus5.1 Thermal-stress testing machineAn example of a test machine for measuring the thermal stress developed in rubbery materials when heated is shown in Figure 1. Two clamps hold the test piece in a temperature-controlled chamber, with the upper clamp connected to a
41、load cell and the bottom clamp connected to a crosshead. The crosshead is moved using a screw driven by a motor to impose a pre-strain on the test piece. The thermal stress developed when the temperature is raised is transmitted to the load cell and the output is recorded to give the variation in st
42、ress as a function of time.The test machine shall comply with ISO 5893 with force measurement to class 1 and the machine shall be capable of setting the pre-strain to within 0,1 at a speed of (20 2,5) mm/min.2 ISO 2017 All rights reservedBS ISO 12493:2017ISO 12493:2017(E)3.3thermal stress after a sp
43、ecified timeT,tstress induced in the test piece upon heating for a specified time t3.4pre-strainelongation to which the test piece is subjected at the beginning of the testNote 1 to entry: It is expressed as:pre-strainfii=lllwhereliis the initial length;lfis the length after elongation.3.5pre-stress
44、force per initial unit area which results from the pre-strainNote 1 to entry: It is expressed in N/m2or Pa.4 PrincipleA test piece is held at a constant pre-strain in a tensile mode at standard laboratory temperature. When the pre-stress resulting from the given pre-strain has reached an apparent eq
45、uilibrium value, the temperature of the test piece is increased. The thermal stress developed at the elevated temperature is measured for various pre-strain conditions as a function of time.5 Apparatus5.1 Thermal-stress testing machineAn example of a test machine for measuring the thermal stress dev
46、eloped in rubbery materials when heated is shown in Figure 1. Two clamps hold the test piece in a temperature-controlled chamber, with the upper clamp connected to a load cell and the bottom clamp connected to a crosshead. The crosshead is moved using a screw driven by a motor to impose a pre-strain
47、 on the test piece. The thermal stress developed when the temperature is raised is transmitted to the load cell and the output is recorded to give the variation in stress as a function of time.The test machine shall comply with ISO 5893 with force measurement to class 1 and the machine shall be capa
48、ble of setting the pre-strain to within 0,1 at a speed of (20 2,5) mm/min.2 ISO 2017 All rights reserved ISO 12493:2017(E)Key1 temperature-controlled chamber2 clamps3 load cell4 rod5 linear variable differential transformer6 screw7 crosshead8 motorFigure 1 Example of thermal-stress testing machine5.
49、2 Temperature-controlled chamberThe temperature-controlled chamber shall be capable of raising the temperature at a rate of at least 30 C/min and maintaining the test piece at the required temperature as specified in ISO 23529. A suitable volume for the chamber is 3 l to 5 l. A temperature-sensing device shall be located within the chamber near the test piece.5.3 Thickness- and width-measuring devicesInstruments for measuring the thickness and width of the test piece shall be in accordance with
