1、BS EN ISO22088-5:2009ICS 83.080.01NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBRITISH STANDARDPlastics Determinationof resistance toenvironmental stresscracking (ESC)Part 5: Constant tensile deformationmethod (ISO 22088-5:2006)This British Standardwas published under theaut
2、hority of the StandardsPolicy and StrategyCommittee on 31 July 2009 BSI 2009ISBN 978 0 580 57122 0Amendments/corrigenda issued since publicationDate CommentsBS EN ISO 22088-5:2009National forewordThis British Standard is the UK implementation of EN ISO22088-5:2009. It is identical to ISO 22088-5:200
3、6.The UK participation in its preparation was entrusted to TechnicalCommittee PRI/21, Testing of plastics.A list of organizations represented on this committee can be obtained onrequest to its secretary.This publication does not purport to include all the necessary provisionsof a contract. Users are
4、 responsible for its correct application.Compliance with a British Standard cannot confer immunityfrom legal obligations.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 22088-5June 2009ICS 83.080.01English VersionPlastics - Determination of resistance to environmental stresscracking (ESC) - Pa
5、rt 5: Constant tensile deformation method(ISO 22088-5:2006)Plastiques - Dtermination de la fissuration sous contraintedans un environnement donn (ESC) - Partie 5: Mthodede dformation en traction constante (ISO 22088-5:2006)Kunststoffe - Bestimmung der Bestndigkeit gegenumgebungsbedingte Spannungsris
6、sbildung (ESC) - Teil 5:Verfahren mit konstanter Zugverformung (ISO 22088-5:2006)This European Standard was approved by CEN on 23 May 2009.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a nationa
7、l standard 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 o
8、ther language 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,
9、 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.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES K
10、OMITEE FR NORMUNGManagement Centre: Avenue Marnix 17, B-1000 Brussels 2009 CEN All rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 22088-5:2009: EBS EN ISO 22088-5:2009EN ISO 22088-5:2009 (E) 3 Foreword The text of ISO 22088-5:2006 has b
11、een prepared by Technical Committee ISO/TC 61 “Plastics” of the International Organization for Standardization (ISO) and has been taken over as EN ISO 22088-5:2009 by Technical Committee CEN/TC 249 “Plastics” the secretariat of which is held by NBN. This European Standard shall be given the status o
12、f a national standard, either by publication of an identical text or by endorsement, at the latest by December 2009, and conflicting national standards shall be withdrawn at the latest by December 2009. Attention is drawn to the possibility that some of the elements of this document may be the subje
13、ct of patent rights. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bul
14、garia, 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 the United Kingdom. Endorsement notice The tex
15、t of ISO 22088-5:2006 has been approved by CEN as a EN ISO 22088-5:2009 without any modification. BS EN ISO 22088-5:2009ISO 22088-5:2006(E) ISO 2006 All rights reserved iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Principle. 3 5 Apparatus 4 6 Condi
16、tioning and test conditions 5 6.1 Conditioning 5 6.2 Test temperature. 5 6.3 Test medium 5 7 Test specimens . 5 7.1 Shape and dimensions. 5 7.2 Number 5 7.3 Preparation 6 8 Test stress . 6 9 Procedure 7 10 Expression of results . 7 11 Precision 7 12 Test report . 8 Bibliography . 9 BS EN ISO 22088-5
17、:2009ISO 22088-5:2006(E) iv ISO 2006 All rights reservedForeword 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 technical committees
18、. 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 Intern
19、ational 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 International Sta
20、ndards 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 document may be the subj
21、ect of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 22088-5 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 6, Ageing, chemical and environmental resistance. ISO 22088 consists of the following parts, under the general t
22、itle Plastics Determination of resistance to environmental stress cracking (ESC): Part 1: General guidance Part 2: Constant tensile load method (replacement of ISO 6252:1992) Part 3: Bent strip method (replacement of ISO 4599:1986) Part 4: Ball or pin impression method (replacement of ISO 4600:1992)
23、 Part 5: Constant tensile deformation method (new test method) Part 6: Slow strain rate method (new test method) BS EN ISO 22088-5:2009INTERNATIONAL STANDARD ISO 22088-5:2006(E) ISO 2006 All rights reserved 1Plastics Determination of resistance to environmental stress cracking (ESC) Part 5: Constant
24、 tensile deformation method 1 Scope This part of ISO 22088 specifies a method for the determination of the environmental stress cracking (ESC) behaviour of thermoplastics when they are subjected to a constant tensile deformation in the presence of a chemical medium. It is applicable to test specimen
25、s prepared by moulding and/or machining and can be used for the assessment of the ESC behaviour of plastic materials exposed to different environments, as well as for the determination of the ESC behaviour of different plastic materials exposed to a specific environment. This is essentially a rankin
26、g test and is not intended to provide data to be used for design or performance prediction. NOTE Alternative methods for the determination of environmental stress cracking by means of a constant-strain test are specified in ISO 22088-3 and ISO 22088-4. A method for the determination of environmental
27、 stress cracking by means of a constant tensile load is specified in ISO 22088-2. 2 Normative references The 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
28、referenced document (including any amendments) applies. ISO 293, Plastics Compression moulding of test specimens of thermoplastic materials ISO 294-1, Plastics Injection moulding of test specimens of thermoplastic materials Part 1: General principles, and moulding of multipurpose and bar test specim
29、ens ISO 294-5, Plastics Injection moulding of test specimens of thermoplastic materials Part 5: Preparation of standard specimens for investigating anisotropy ISO 527-2, Plastics Determination of tensile properties Part 2: Test conditions for moulding and extrusion plastics ISO 2818, Plastics Prepar
30、ation of test specimens by machining ISO 22088-1:2006, Plastics Determination of resistance to environmental stress cracking (ESC) Part 1: General guidance BS EN ISO 22088-5:2009ISO 22088-5:2006(E) 2 ISO 2006 All rights reserved3 Terms and definitions For the purposes of this document, the following
31、 terms and definitions apply. 3.1 stress relaxation time-dependent decrease in stress 3.2 initial stress stress occurring when a specimen is first subjected to a constant strain 3.3 stress ratio ratio of the initial stress to the stress after a certain amount of time 3.4 stress relaxation curve curv
32、e obtained by plotting the stress ratio as ordinate and the logarithm of time as abscissa 3.5 critical stress maximum stress that can be applied without altering the stress relaxation curve NOTE The shape of a stress relaxation curve depends upon the strain applied (see Figure 1). Below a certain st
33、rain, further reduction of the strain does not change the curve. The stress at this particular strain is defined as the critical stress. Key t time 0initial stress stress at time t /0stress ratio NOTE 1 The numbers 1 to 5 indicate the order in which the tests were performed. NOTE 2 The strains appli
34、ed to the specimens were as follows: curve 2 curve 1 curve 3 curve 4 curve 5. NOTE 3 The stress applied in curve 4 corresponds to the critical stress. Figure 1 Determination of critical stress BS EN ISO 22088-5:2009ISO 22088-5:2006(E) ISO 2006 All rights reserved 34 Principle A specimen held at a co
35、nstant deformation is exposed to a chosen chemical environment at a selected test temperature. The deformation is produced by an initial tensile force that is lower than that at the yield point (or that at the breaking point if the material does not exhibit a yield point) and is held in place by a d
36、evice such as a worm-gear. The environmental stress cracking behaviour of the test specimen is evaluated by comparing the critical stress in a selected chemical environment with the critical stress for the same material in air. Comparing the shape of the stress relaxation curve obtained after an ini
37、tial stress is applied in a selected chemical environment with that of the stress relaxation curve obtained when the same initial stress is applied in air is also an essential part of the evaluation. The critical stress may be used as an index for ESC. For example, if the critical stress obtained in
38、 a particular chemical environment is less than that in air, the material is regarded as being affected by the chemical environment. In addition, it is possible to determine quantitatively the degree of ESC as the difference between the critical stress in air and that in the chemical environment. Th
39、e shape of the stress relaxation curve may also be used as a qualitative index of ESC. In Figure 2, curve A is the reference curve in air. Curve B deviates downwards from curve A due to a slight swelling effect caused by the chemical used for this test. Plastics in this state may be safely used when
40、 exposed to this chemical if the maximum allowed stress is relatively low. Curve C shows how the molecular structure of a polymer can be weakened by continuous ESC. Curve D indicates how the stress can be reduced very significantly by ESC. Plastics which give curves like C and D are not suitable for
41、 use in the chemical environment concerned. Key t time 0initial stress stress at time t /0stress ratio Figure 2 Classification of stress relaxation curves BS EN ISO 22088-5:2009ISO 22088-5:2006(E) 4 ISO 2006 All rights reserved5 Apparatus 5.1 Test device, allowing test specimens to be held at a cons
42、tant tensile deformation while exposed to a chemical medium (Figure 3 is a schematic diagram of a suitable apparatus). A strain gauge with an accuracy of 1% can be used to measure the tensile load. The parts of the device which come into contact with the chemical medium shall be made of, or coated w
43、ith, an inert material, such as stainless steel, polytetrafluoroethylene or another suitable material. Care shall be taken that the specimens are subjected only to forces parallel to their longitudinal axis, and not to bending or twisting forces. Key 1 worm-gear 5 clamp 2 screw 6 glass container 3 l
44、oad cell 7 test specimen 4 cover 8 chemical medium Figure 3 One type of apparatus for stress relaxation testing BS EN ISO 22088-5:2009ISO 22088-5:2006(E) ISO 2006 All rights reserved 55.2 Temperature-controlled bath or oven, allowing the containers to be maintained at (23 2) C or at a higher test te
45、mperature up to 100 C to within 2 C (see Clause 6). 5.3 Containers, allowing the test assembly to be immersed completely in a test medium, with a cover that can be sealed for chemicals which are volatile at the immersion temperature. Materials used for containers shall not interact with the immersio
46、n liquid. 5.4 Equipment for the preparation of test specimens by moulding (see ISO 293, ISO 294-1 and ISO 294-5), machining (see ISO 2818) or die cutting. 6 Conditioning and test conditions 6.1 Conditioning Unless otherwise specified in the relevant material standard or agreed upon between the inter
47、ested parties, the test specimen shall be conditioned before testing for at least 24 h at (23 2) C and (50 10) % relative humidity. 6.2 Test temperature The preferred test temperatures are (23 2) C and (55 2) C. If required, other temperatures may be used, preferably selected from the following: (40
48、 2) C, (70 2) C, (85 2) C, (100 2) C, or as agreed upon by the interested parties. 6.3 Test medium See ISO 22088-1:2006, 7.3 7 Test specimens 7.1 Shape and dimensions The shape and dimensions of the test specimen shall be as given in Figure 4. This test specimen is the half-size type 1BA test specim
49、en specified in ISO 527-2. The preferred thickness is (2 0,2) mm, but when the test specimens are prepared from finished products the thickness may be that of the product. Alternatively, a type 1BA specimen 3 mm to 4 mm thick may be used. 7.2 Number The number of test specimens required for one set of test conditions is 10, i.e. 5 specimens in test medium and in air, respectively. NOTE If the material is thought to be anisotropic, two sets of specimens shall be use
