1、 g49g50g3g38g50g51g60g44g49g42g3g58g44g55g43g50g56g55g3g37g54g44g3g51g40g53g48g44g54g54g44g50g49g3g40g59g38g40g51g55g3g36g54g3g51g40g53g48g44g55g55g40g39g3g37g60g3g38g50g51g60g53g44g42g43g55g3g47g36g58environmental stress cracking (ESC) Part 3: Bent strip methodThe European Standard EN ISO 22088-3:2
2、006 has the status of a British StandardICS 83.080.01Plastics Determination of resistance to BRITISH STANDARDBS EN ISO 22088-3:2006BS EN ISO 22088-3:2006This British Standard was published under the authority of the Standards Policy and Strategy Committee on 29 September 2006 BSI 2006ISBN 0 580 4876
3、8 7Amendments issued since publicationAmd. No. Date CommentsThis publication does not purport to include all the necessary provisions of a contract. Users are responsible for its correct application.Compliance with a British Standard cannot confer immunity from legal obligations. National forewordTh
4、is British Standard was published by BSI. It is the UK implementation of EN ISO 22088-3:2006. It supersedes BS EN ISO 4599:1997 which is withdrawn.The UK participation in its preparation was entrusted to Technical Committee PRI/21, Testing of plastics.A list of organizations represented on PRI/21 ca
5、n be obtained on request to its secretary.EUROPEAN STANDARDNORME EUROPENNEEUROPISCHE NORMEN ISO 22088-3August 2006ICS 83.080.01 Supersedes EN ISO 4599:1996 English VersionPlastics - Determination of resistance to environmental stresscracking (ESC) - Part 3: Bent strip method (ISO 22088-3:2006)Plasti
6、ques - Dtermination de la fissuration sous contraintedans un environnement donn (ESC) - Partie 3: Mthodede lprouvette courbe (ISO 22088-3:2006)Kunststoffe - Bestimmung der Bestndigkeit gegenumgebungsbedingte Spannungsrissbildung (ESC) - Teil 3:Biegestreifenverfahren (ISO 22088-3:2006)This European S
7、tandard was approved by CEN on 21 July 2006.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 standard without any alteration. Up-to-date lists and bibliographical references concerning s
8、uch nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language a
9、nd notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Net
10、herlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMIT EUROPEN DE NORMALISATIONEUROPISCHES KOMITEE FR NORMUNGManagement Centre: rue de Stassart, 36 B-1050 Brussels 2006 CEN All rights of exploitation i
11、n any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 22088-3:2006: EForeword This document (EN ISO 22088-3:2006) has been prepared by Technical Committee ISO/TC 61 “Plastics“ in collaboration with Technical Committee CEN/TC 249 “Plastics“, the secretariat of which i
12、s held by IBN. 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 February 2007, and conflicting national standards shall be withdrawn at the latest by February 2007. This document supersedes EN ISO
13、4599:1996. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy,
14、 Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom. Endorsement notice The text of ISO 22088-3:2006 has been approved by CEN as EN ISO 22088-3:2006 without any modifications. EN ISO 22088-3:2006Refe
15、rence numberISO 22088-3:2006(E)INTERNATIONAL STANDARD ISO22088-3First edition2006-08-15Plastics Determination of resistance to environmental stress cracking (ESC) Part 3: Bent strip method Plastiques Dtermination de la fissuration sous contrainte dans un environnement donn (ESC) Partie 3: Mthode de
16、lprouvette courbe EN ISO 22088-3:2006ii iiiContents Page Foreword iv 1 Scope . 1 2 Normative references . 1 3 Terms and definitions. 2 4 Principle. 4 5 Apparatus 4 6 Test specimens . 5 6.1 Form and dimensions. 5 6.2 Preparation 5 6.3 Number 5 7 Conditioning and test conditions 5 7.1 Conditioning 5 7
17、.2 Test temperature. 5 7.3 Test medium 5 8 Procedure 5 8.1 Precautions . 5 8.2 Mounting the test specimens 5 8.3 Contact with the test environment 6 8.4 Storage in contact with the test environment6 8.5 Determination of the indicative property 7 9 Expression of results . 7 9.1 Calculation. 7 9.2 Gra
18、phical evaluation. 7 10 Precision 8 11 Test report . 9 Bibliography . 10 EN ISO 22088-3:2006iv Foreword 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 carri
19、ed 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 non-governmental, in liaison with ISO, also take part in the work. I
20、SO collaborates closely 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 Internati
21、onal Standards. Draft 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 el
22、ements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 22088-3 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 6, Ageing, chemical and environmental resistance. It cancels and replaces
23、 ISO 4599:1986, which has been technically revised. ISO 22088 consists of the following parts, under the general title 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: Ben
24、t strip method (replacement of ISO 4599:1986) Part 4: Ball or pin impression method (replacement of ISO 4600:1992) Part 5: Constant tensile deformation method (new test method) Part 6: Slow strain rate method (new test method) EN ISO 22088-3:20061Plastics Determination of resistance to environmental
25、 stress cracking (ESC) Part 3: Bent strip method 1 Scope This part of ISO 22088 specifies a method for the determination of the environmental stress cracking (ESC) resistance of thermoplastics when they are subjected to a fixed flexural strain in the presence of chemical agents. ESC is indicated by
26、the change of a suitably chosen indicative property of specimens that have been strained for a defined time in the environment. The method of test is suitable for determining the resistance of sheets and of flat test specimens, especially the sensitivity of localized surface regions of specimens, to
27、 ESC. The bent strip method is suitable for the determination of ESC caused by gases and liquids as well as solids containing migrating substances (e.g. polymeric adhesives and materials containing plasticizers) in contact with a specific polymer. Preferably, this method is used to determine the ESC
28、 resistance of rigid plastics that exhibit only moderate stress relaxation during the time of the test. This is essentially a ranking test and is not intended to provide data to be used for design or performance prediction. NOTE For a constant-strain test, refer to ISO 22088-5. For a constant-load t
29、est, refer to 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 referenced document (including any amendments) applies.
30、 ISO 178, Plastics Determination of flexural properties ISO 179-1, Plastics Determination of Charpy impact properties Part 1: Non-instrumented impact test ISO 527-2, Plastics Determination of tensile properties Part 2: Test conditions for moulding and extrusion plastics ISO 2818, Plastics Preparatio
31、n of test specimens by machining ISO 22088-1:2006, Plastics Determination of resistance to environmental stress cracking (ESC) Part 1: General guidance EN ISO 22088-3:20062 3 Terms and definitions For the purposes of this document, the following terms and definitions apply. 3.1 flexural strain xnomi
32、nal value of the strain in the tensile surface of a flat test specimen of thickness h, bent over the segment of a circle with radius r, calculated from the equation x2hrh =+NOTE See Figure 1. Key 1 clamps 2 test specimen: tensile surface in contact with test medium compressive surface in contact wit
33、h form 3 form h thickness of test specimen r radius of form xnominal strain in tensile surface Figure 1 Test specimen with defined strain in the tensile surface 3.2 strain value one of a series of strain levels applied to successive test specimens during exposure 3.3 strain series a number of strain
34、 values, including zero NOTE 1 Normally, the results of the mechanical test on test specimens with zero applied strain are equivalent whether determined in air or in a chemical test medium. If the property measured after exposure to the test medium at zero strain is different from that after exposur
35、e in air at zero strain, embrittlement or softening by the test medium should be suspected. In some cases, relief of stresses imparted during specimen preparation such as by injection-moulding or machining can contribute to differences in results for stress cracking in air and another test medium. N
36、OTE 2 It is recommended that the test specimen for zero strain be clamped on to a flat form to prevent warping due to the effect of the test medium. EN ISO 22088-3:200633.4 failure strain Flowest strain in the strain series at which failure is observed 3.5 indicative property property observed to de
37、termine failure using a criterion such as those given in Table 1 3.6 ESC index ratio of the value of failure strain determined in the test medium to that determined in the reference medium (usually air) for the same time of exposure Table 1 Suggested indicative properties and failure criteria (see N
38、ote 1) Indicative property International Standard Failure criterion Designation State of surface (assessed by visual examination) Cracks or crazes around the tensile surface edges A1 State of surface (assessed by visual examination) Cracks or crazes in the tensile surface A2 State of surface (assess
39、ed by visual examination) Any other observation, e.g. change in colour or appearance A3 Tensile stress at break or tensile stress at yield ISO 527-2 80 % of the value obtained on unstrained unexposed test specimens (see Note 2) B1 Flexural stress at maximum load ISO 178 80 % of the value obtained on
40、 unstrained unexposed test specimens (see Note 2) B2 Percentage tensile strain at break or tensile strain at yield ISO 527-2 50 % of the value obtained on unstrained unexposed test specimens (see Note 2) B3 Charpy impact strength, unnotched ISO 179-1 50 % of the value obtained on unstrained unexpose
41、d test specimens (see Note 3) B4 Tensile impact strength See Note 4 50 % of the value obtained on unstrained unexposed test specimens B5 Any other property agreed upon To be agreed B6 NOTE 1 The state of the test specimens, the indicative property and the failure criterion shall be selected with a v
42、iew to the practical service conditions. NOTE 2 If the material is thought to be anisotropic, two sets of specimens shall be used, one set cut at right angles to the other in two of the principal directions of orientation. This applies only to specimens having the appropriate dimensions. NOTE 3 Data
43、 comparisons will only be valid if the failure mode is the same in all cases. NOTE 4 This question is under study. EN ISO 22088-3:20064 4 Principle A test specimen suitable for the determination of the indicative property is clamped with one of its faces over a form of constant radius and brought in
44、to contact with the test environment. Due to the influence of the environment in the presence of strain, crazes may be generated which with time sometimes develop into visible cracks. By using a series of forms with decreasing radii, a series of test specimens that have increasing strains in the out
45、er surface can be tested. After an agreed duration of contact with the test environment, the test specimens are visually observed, unclamped and assessed by mechanical or other testing. The failure strain that corresponds to the failure criterion is obtained directly from the tabulated values or gra
46、phically. The maximum strain must be less than the strain at yield. NOTE 1 The failure criterion is also commonly expressed in terms of the ESC index. NOTE 2 The failure strains for different indicative properties may be different. 5 Apparatus 5.1 Forms, made from chemical-resistant material either
47、by machining or by bending metal sheet (for example, stainless-steel sheet). For test specimens 2 mm to 4 mm thick, radii of curvature of 30 mm to 500 mm are suitable. The form shall have roughly the same length as the test specimen. To increase the contact between the test specimen and the test med
48、ium, the forms may be perforated. NOTE The radius r of the segment of a circular arc of height h and chord length l is given by the equation 282lhrh=+ 5.2 Clamps, made from chemical-resistant material. The clamps shall be designed so that they hold the test specimen lightly. The contact between the
49、test specimen and the form need not extend to the clamps, but shall extend over that length of test specimen which will be most highly stressed in the subsequent mechanical test. In no case shall the contact region (measured in the direction of the length of the test specimen) be less than 10 times the specimen thickness. 5.3 Vessels, such as carefully cleaned glass containers with well fitting lids, suitable for holding the mounted test specimens and the test medium. Ot
