1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58Test methodsThe European Standard EN ISO 252:2007 has the status of a British StandardICS 53.040.20
2、Conveyor belts Adhesion between constitutive elements BRITISH STANDARDBS EN ISO 252:2007BS EN ISO 252:2007This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2007 BSI 2007ISBN 978 0 580 53859 9Amendments issued since publicationAmd. No. D
3、ate Commentscontract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations.National forewordThis British Standard was published by BSI. It is the UK implementation of EN ISO 252:2007. It supersedes BS EN ISO 252-1:1999 whi
4、ch is withdrawn. The UK participation in its preparation was entrusted to Technical Committee PRI/67, Conveyor belts.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 EUROPE
5、AN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 252June 2007ICS 53.040.20 Supersedes EN ISO 252-1:1999 English VersionConveyor belts - Adhesion between constitutive elements - Testmethods (ISO 252:2007)Courroies transporteuses - Adhrence entre lmentsconstitutifs - Mthodes dessai (ISO 252:2007)Frderg
6、urte - Lagenhaftung zwischen den Bestandteilen -Prfverfahren (ISO 252:2007)This European Standard was approved by CEN on 23 May 2007.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national stan
7、dard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the CEN Management Centre or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other l
8、anguage made by translationunder the responsibility of a CEN member into its own language and notified to the CEN Management Centre has the same status as theofficial versions.CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Cyprus, Czech Republic, Denmark, Estonia, Finla
9、nd,France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal,Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE
10、 FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2007 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 252:2007: E2 Foreword This document (EN ISO 252:2007) has been prepared by Technical Committee ISO/TC 41 “Pull
11、eys and belts (including veebelts)“ in collaboration with Technical Committee CEN/TC 188 “Conveyor belts“, the secretariat of which is held by BSI. 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
12、December 2007, and conflicting national standards shall be withdrawn at the latest by December 2007. This document supersedes EN ISO 252-1:1999. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Sta
13、ndard: Austria, Belgium, Bulgaria, 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 and United Kingdom. En
14、dorsement notice The text of ISO 252:2007 has been approved by CEN as EN ISO 252:2007 without any modifications. EN ISO 252:2007Reference numberISO 252:2007(E)INTERNATIONAL STANDARD ISO252Third edition2007-06-15Conveyor belts Adhesion between constitutive elements Test methods Courroies transporteus
15、es Adhrence entre lments constitutifs Mthodes dessai EN ISO 252:2007ii iiiForeword ISO (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 te
16、chnical 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 close
17、ly 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. Draft
18、 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 docume
19、nt may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 252 was prepared by Technical Committee ISO/TC 41, Pulleys and belts (including veebelts), Subcommittee SC 3, Conveyor belts. This third edition of ISO 252 cancels and replace
20、s ISO 252-1:1999, of which it constitutes a technical revision. It also incorporates the Technical Corrigendum, ISO 252-1:1999/Cor. 1:2006. EN ISO 252:2007blank1Conveyor belts Adhesion between constitutive elements Test methods 1 Scope This International Standard specifies two test methods, A and B,
21、 for determining the adhesion strength between constitutive elements of a conveyor belt, i.e. between plies and between covers and carcass. Basic test conditions are in conformity with ISO 36. It is applicable to all types of construction of conveyor belting with the exception of belts containing st
22、eel cord reinforcement, and textile-reinforced belts with a full-thickness tensile strength of less than 160 N/mm. It is not suitable or valid for light conveyor belts as described in ISO 21183-11. NOTE Methods A and B are alternative options, but the mean adhesive force values calculated for the tw
23、o methods can be different. Also, as both methods might not be equally suitable for all belt constructions, it is advisable that the advice of the belt manufacturer be sought. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated
24、references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 36, Rubber, vulcanized or thermoplastic Determination of adhesion to textile fabrics ISO 6133, Rubber and plastics Analysis of multi-peak traces o
25、btained in determinations of tear strength and adhesion strength ISO 18573, Conveyor belts Test atmospheres and conditioning periods 3 Principle The mean force required to strip the covers from the carcass, and also each ply from the next, is determined using a constant rate of traverse machine. 4 A
26、pparatus Suitable power-driven tensile testing machine, conforming to ISO 36. 5 Test pieces 5.1 Time between manufacture and test The time between completion of production and the commencement of testing shall be not less than 24 h; this period shall include the conditioning periods given in 5.5. EN
27、 ISO 252:20072 5.2 Shape and dimensions Each test piece shall consist of a strip of belting of rectangular cross-section with clean-cut edges, (25 0,5) mm wide and 200 mm minimum in length, so as to permit a length of at least 100 mm to be stripped. If necessary and where possible, the thickness sha
28、ll be reduced to a value which will ensure that during the test the line of separation remains as near as possible to the plane through the axes of the components of the test piece held between the grips (see Figure 1). The minimum thickness shall be such that the weakest component can transmit the
29、necessary force for separation without breaking. Key 1 plane through axes of components of test piece held between grips 2 line of separation (correct alignment with plane through axes) 3 line of separation (incorrect alignment with plane through axes) 4 test piece with reduced thickness to improve
30、alignment Figure 1 Position of line of separation of plies 5.3 Number For both methods, A and B, two test pieces in the longitudinal direction shall be used. The test may also be conducted with two transverse test pieces, if agreed between the manufacturer and purchaser. EN ISO 252:200735.4 Selectio
31、n of test pieces from sample The test pieces shall be taken not less than 100 mm from the edges of the available belt sample and from places as widely spaced as possible. 5.5 Conditioning Condition the test pieces in accordance with ISO 18573, using either atmosphere D or atmosphere E, and then carr
32、y out the tests immediately after completion of the conditioning period. 6 Procedure 6.1 Method A (see Figure 2) At one end of the longitudinal test piece, separate the top cover from the first ply for a distance appropriate to the test grips to be used. Fix the separated ends in the grips of the te
33、nsile testing machine and make an autographic record of the force required to strip a further 100 mm with a rate of traverse of the driven jaw of (100 10) mm/min. The test piece shall be unsupported. Repeat this procedure using the same test piece for each consecutive ply up to the middle of the tes
34、t piece. Carry out a similar series of tests on a second longitudinal test piece but commencing with the bottom cover. If the test is to be carried out on transverse test pieces, conduct the test in the same manner. Any separation occurring outside the plane of contact between the two components, fo
35、r example, inside one of the components (such as a cover) subjected to the test, is considered as a rupture of the material which constitutes the component. Such a separation should be noted, but should not be considered as representative of the adhesion strength. EN ISO 252:20074 Key 1 top cover 2
36、bottom cover Figure 2 Sequence of separation of components for method A (5-ply belt shown as example) EN ISO 252:200756.2 Method B (see Figure 3) At one end of the longitudinal test piece, separate the top cover from the first ply for a suitable distance appropriate to the test grips to be used. Fix
37、 the separated ends in the grips of the tensile testing machine and make an autographic record of the force required to strip a further 100 mm with a rate of traverse of the driven jaw of (100 10) mm/min. The test piece shall be unsupported. Key 1 top cover 2 bottom cover Figure 3 Sequence of separa
38、tion of components for method B (5-ply belt shown as example) EN ISO 252:20076 Repeat this procedure using the same test piece, stripping consecutively two unseparated plies from the remainder of the test piece. Carry out a similar series of tests on a second longitudinal test piece but commencing b
39、y separating the unseparated top cover and first ply from the second ply. If the test is to be carried out on transverse test pieces, conduct the test in the same manner. Any separation occurring outside the plane of contact between the two components, for example, inside one of the components (such
40、 as a cover) subjected to the test, is considered as a rupture of the material which constitutes the component. Such a separation should be noted, but should not be considered as representative of the adhesion strength. 7 Expression of results 7.1 Examination of traces for longitudinal test pieces E
41、xamination and analysis of the multi-peak adhesion strength test traces shall be in accordance with ISO 6133. The median peak force is defined as the mean adhesion force. The lowest graphically recorded peak is defined as the minimum adhesion force. Calculate the mean adhesion as the quotient of the
42、 mean adhesion force, in Newtons, divided by the nominal width, in millimetres, of the test piece to the nearest 0,1 N/mm. Calculate the minimum adhesion as the quotient of the minimum adhesion force, in Newtons, divided by the nominal width, in millimetres, of the test piece to the nearest 0,1 N/mm
43、. 7.2 Examination of traces for transverse test pieces Make calculations in accordance with 7.1 for the two test pieces cut transversely, if applicable. 8 Test report The test report shall contain the following information: a) reference to this International Standard (i.e. ISO 252); b) identificatio
44、n of the conveyor belt tested; c) time interval between belt manufacture and test piece preparation; d) temperature and times for conditioning and testing; e) test method used (A or B); f) mean adhesion, as calculated in accordance with 7.1, for the top cover to ply or carcass measurement, the botto
45、m cover to ply or carcass measurement and for each ply to ply measurement; g) minimum adhesion, as calculated in accordance with 7.1, for the top cover to ply or carcass measurement, the bottom cover to ply or carcass measurement and for each ply to ply measurement; h) any case where one of the comp
46、onents fails before the adhesion strength between the two components is reached, and the force at which the failure occurred (see final paragraph of 6.1 and 6.2); i) date of the test. EN ISO 252:20077Bibliography 1 ISO 21183-1, Light conveyor belts Part 1: Principal characteristics and applications
47、EN ISO 252:2007BS EN ISO BSI389 Chiswick High RoadLondonW4 4AL252:2007BSI British Standards InstitutionBSI is the independent national body responsible for preparing British Standards. It presents the UK view on standards in Europe and at the international level. It is incorporated by Royal Charter.
48、RevisionsBritish Standards are updated by amendment or revision. Users of British Standards should make sure that they possess the latest amendments or editions.It is the constant aim of BSI to improve the quality of our products and services. We would be grateful if anyone finding an inaccuracy or
49、ambiguity while using this British Standard would inform the Secretary of the technical committee responsible, the identity of which can be found on the inside front cover. Tel: +44 (0)20 8996 9000. Fax: +44 (0)20 8996 7400.BSI offers members an individual updating service called PLUS which ensures that subscribers automatically receive the latest editions of standards.Buying standardsOrders for all BSI, international and foreign standards publications should be addressed to Customer Servic
