1、BSI Standards PublicationBS EN 13523-7:2014Coil coated metals TestmethodsPart 7: Resistance to cracking on bending(T-bend test)BS EN 13523-7:2014 BRITISH STANDARDNational forewordThis British Standard is the UK implementation of EN 13523-7:2014.It supersedes BS EN 13523-7:2001 which is withdrawn.The
2、 UK participation in its preparation was entrusted to TechnicalCommittee STI/21, Surface preparation of steel.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include all the necessaryprovisions of a contract. Users
3、 are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 80213 3ICS 17.040.20; 25.220.60Compliance with a British Standard cannot confer immunity fromlegal obligations.This British Standard was published under the autho
4、rity of theStandards Policy and Strategy Committee on 30 June 2014.Amendments issued since publicationDate Text affectedBS EN 13523-7:2014EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 13523-7 June 2014 ICS 25.220.60 Supersedes EN 13523-7:2001English Version Coil coated metals - Test methods -
5、 Part 7: Resistance to cracking on bending (T-bend test) Tles prlaques - Mthodes dessai - Partie 7: Rsistance la fissuration par pliage (essai de pliage en T) Bandbeschichtete Metalle - Prfverfahren - Teil 7: Widerstandsfhigkeit gegen Rissbildung beim Biegen (T-Biegeprfung) This European Standard wa
6、s approved by CEN on 7 May 2014. CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nation
7、al standards may be obtained on application to the CEN-CENELEC Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language made by translation under the responsibility of a CEN member into its own languag
8、e and notified to the CEN-CENELEC Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, H
9、ungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG CEN-C
10、ENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels 2014 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 13523-7:2014 EBS EN 13523-7:2014EN 13523-7:2014 (E) 2 Contents Page Foreword 3 1 Scope 5 2 Normative references 5 3 Te
11、rms and definitions .5 4 Principle 5 5 Apparatus .6 6 Sampling 11 7 Test panels 11 8 Procedure 12 8.1 General . 12 8.2 Methods for practical (industrial) use 12 8.2.1 Folding method . 12 8.2.2 Mandrel method 13 8.3 Method for laboratory purposes . 14 9 Expression of results . 14 10 Precision 14 11 T
12、est report . 14 Bibliography . 16 BS EN 13523-7:2014EN 13523-7:2014 (E) 3 Foreword This document (EN 13523-7:2014) has been prepared by Technical Committee CEN/TC 139 “Paints and varnishes”, the secretariat of which is held by DIN. This European Standard shall be given the status of a national stand
13、ard, either by publication of an identical text or by endorsement, at the latest by December 2014, and conflicting national standards shall be withdrawn at the latest by December 2014. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent right
14、s. CEN and/or CENELEC shall not be held responsible for identifying any or all such patent rights. This document supersedes EN 13523-7:2001. The main technical changes are: a) details on the brands of the tape used were added; b) a remark on conditioning was added; c) in addition to use a 10 magnify
15、ing glass, the evaluation shall be carried out with normal corrected vision. EN 13523, Coil coated metals Test methods, consists of the following parts: Part 0: General introduction Part 1: Film thickness Part 2: Gloss Part 3: Colour difference Instrumental comparison Part 4: Pencil hardness Part 5:
16、 Resistance to rapid deformation (impact test) Part 6: Adhesion after indentation (cupping test) Part 7: Resistance to cracking on bending (T-bend test) Part 8: Resistance to salt spray (fog) Part 9: Resistance to water immersion Part 10: Resistance to fluorescent UV radiation and water condensation
17、 Part 11: Resistance to solvents (rubbing test) Part 12: Resistance to scratching Part 13: Resistance to accelerated ageing by the use of heat Part 14: Chalking (Helmen method) BS EN 13523-7:2014EN 13523-7:2014 (E) 4 Part 15: Metamerism Part 16: Resistance to abrasion Part 17: Adhesion of strippable
18、 films Part 18: Resistance to staining Part 19: Panel design and method of atmospheric exposure testing Part 20: Foam adhesion Part 21: Evaluation of outdoor exposed panels Part 22: Colour difference Visual comparison Part 23: Resistance to humid atmospheres containing sulfur dioxide Part 24: Resist
19、ance to blocking and pressure marking Part 25: Resistance to humidity Part 26: Resistance to condensation of water Part 27: Resistance to humid poultice (Cataplasm test) Part 29: Resistance to environmental soiling (Dirt pick-up and striping) According to the CEN-CENELEC Internal Regulations, the na
20、tional standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, L
21、ithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom. BS EN 13523-7:2014EN 13523-7:2014 (E) 5 1 Scope This part of EN 13523 specifies the procedure for determining the resistance to cracking of an o
22、rganic coating on a metallic substrate when bent through 135 to 180. The degree of adhesion may also be evaluated. Both folding and mandrel methods are considered. The folding method is more often used for practical purposes but where more precise determinations are required, the mandrel method is r
23、ecommended. The cylindrical bend method may also be used for a pass/fail decision by using an agreed mandrel. The choice of the appropriate test method is limited by the thickness and/or the hardness of the substrate. The feasibility of the test depends on the type and thickness of the substrate. Du
24、ring the procedure, the mandrel should not deform. 2 Normative references The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edit
25、ion of the referenced document (including any amendments) applies. EN 13523-0:2014, Coil coated metals Test methods Part 0: General introduction EN 23270, Paints and varnishes and their raw materials Temperatures and humidities for conditioning and testing (ISO 3270) EN 60454-2, Pressure-sensitive a
26、dhesive tapes for electrical purposes Part 2: Methods of test (IEC 60454-2) 3 Terms and definitions For the purposes of this document, the terms and definitions given in EN 13523-0:2014 and the following apply. 3.1 metal thickness total thickness of the substrate including any metallic coating and e
27、xcluding any organic coating 4 Principle The coated test specimen is bent parallel to the direction of rolling through 135 to 180 over a period of 1 s to 2 s around various radii with the coating on the outside of the bend. Close contact is maintained between the test specimen and either the wedge o
28、r mandrel to ensure a uniform bend. Any bending device allowing the required smooth and uniform bending may be used. The minimum bending radius to which the specimen can be bent without cracking of the organic coating determines the resistance to cracking on bending through 135 to 180. BS EN 13523-7
29、:2014EN 13523-7:2014 (E) 6 The minimum bending radius to which the specimen can be bent without loss of adhesion determines the resistance to loss of adhesion on bending through 135 to 180. 5 Apparatus 5.1 Bending device5.1.1 for the folding method Vice or suitable bend forming apparatus as shown in
30、 Figure 1. 5.1.2 for the mandrel method Bending device, appropriate to the metal thickness, hardness, and panel size: cylindrical mandrel: see Figure 2; conical mandrel: see Figure 3; conical wedge mandrel: see Figure 4; the conical wedge mandrel may be driven manually (see Figure 5) or pneumaticall
31、y (see Figure 6). 5.2 Magnifying glass 10. 5.3 Transparent pressure-sensitive adhesive tape, 25 mm wide, with an adhesion strength of (10 1) N per 25 mm width when tested in accordance with EN 60454-2. BS EN 13523-7:2014EN 13523-7:2014 (E) 7 Key A apparatus jaws B bending plateC clamping screws D te
32、st specimen 1 direction of movementFigure 1 Practical test (P) folding method BS EN 13523-7:2014EN 13523-7:2014 (E) 8 Figure 2 Laboratory test (L) cylindrical bend BS EN 13523-7:2014EN 13523-7:2014 (E) 9 Figure 3 Laboratory test (L) conical bend Dimensions in millimetres NOTE In this conical wedge m
33、andrel, the distance between each increase of 1 mm radius is 45 mm. This distance should always be equal to or larger than 30 mm so that eventual creep of cracks does not substantially influence the test results. Figure 4 Conical wedge mandrel BS EN 13523-7:2014EN 13523-7:2014 (E) 10 Figure 5 Practi
34、cal test (P) hand operated apparatus BS EN 13523-7:2014EN 13523-7:2014 (E) 11 NOTE Schematic diagram of mechanical test equipment. Key 1 wedge 2 test specimen 3 rubber 4 pneumatic cylinder approximately 6 barFigure 6 Practical test (P) pneumatically driven 6 Sampling See EN 13523-0. Use only flat st
35、rip of such a size that the required procedure can be executed and the results obtained are representative of the end use of the material. 7 Test panels See EN 13523-0. BS EN 13523-7:2014EN 13523-7:2014 (E) 12 Because of possible burrs, up to 5 mm on extreme edges shall be ignored during evaluation.
36、 The coating surface shall be free of oil and other foreign matter that might influence the flexibility of the coating or interfere with the observation for cracking or loss of adhesion. 8 Procedure 8.1 General Measure the resistance of the organic coating to cracking at ambient temperature. For mor
37、e accurate measurements, as required for instance in the case of dispute, the temperature shall be (23 2) C and the relative humidity (50 5) %, in accordance with EN 23270. Conditioning is carried out in accordance with EN 13523-0:2014, Clause 6. The coating under test shall always be at the outside
38、 of the bend. The bending shall be carried out over a period of 1 s to 2 s. The bends shall be examined using normal corrected vision and the magnifying glass (5.2) immediately after bending. If necessary, a second inspection may be agreed after a specified ageing (see, for example, EN 13523-13) of
39、either the flat material before bending or the bend itself. The adhesion may also be evaluated as follows: Remove two complete laps from a reel of the adhesive tape (5.3) and discard. Remove an additional length at a steady rate and cut a piece, approximately 75 mm long. Place the centre of the tape
40、 along the length of the bend and smooth the tape into place over for a distance of at least 20 mm either side with a finger. To ensure good contact with the coating, rub the tape firmly with a fingertip. The colour of the coating seen through the tape is a useful indication of overall contact. With
41、in 5 min of applying the tape, remove the tape by holding the free end and pulling it off steadily in 0,5 s to 1 s at an angle that is as close as possible to 60 to the panel. In cases of dispute, one of the following test methods shall be agreed between the interested parties. 8.2 Methods for pract
42、ical (industrial) use 8.2.1 Folding method The apparatus (5.1.1) shall be firmly secured near the edge of a bench, so that the handle can be operated freely. The test specimen shall be firmly clamped between the jaws of the device or vice, with the painted surface to be evaluated facing downwards, o
43、r, in the case of the vice, facing the operator. The handle operating the bending plate shall be lifted smoothly over a period of 1 s to 2 s. This operation shall be repeated with the test specimen being examined immediately after each bend, with normal corrected vision and the magnifying glass (5.2
44、). In the instance of a vice being used where no bending plate is available, even pressure shall be applied with both thumbs, to ensure a smooth and uniform bending operation (see Figure 7). This method can result in peaking of the bend. Therefore, for more precise results one of the other methods s
45、hould be used. BS EN 13523-7:2014EN 13523-7:2014 (E) 13 Key A vice jaws B test specimen C thumb 1 direction of movement 2 T bends ECCA 3 correct 4 incorrect 5 rolling direction of coil Figure 7 T-bend test 8.2.2 Mandrel method The test specimen shall be placed on an appropriate thick and flexible ru
46、bber mat, the painted surface facing towards the rubber. Either by hand or pneumatically, either the cylindrical mandrels in decreasing radius-order BS EN 13523-7:2014EN 13523-7:2014 (E) 14 or the conical wedge mandrel (see Figures 4, 5 and 6) shall be pressed deep enough into the rubber to ensure t
47、he proper deformation of the test specimen, with the bending parallel to the direction of rolling. For cylindrical bends mandrels having radii from 0,5 mm to 5 mm, with steps of 0,5 mm, shall be used. For a 0T-bend a mandrel of radius 0,5 mm shall be used, and the resulting bend totally bent flat. 8
48、.3 Method for laboratory purposes The coated panel shall be inserted in the apparatus in such a way that a smooth cylindrical or conical bending through 135 to 180 can be achieved. Any device that allows such a smooth and uniform bending within a period of 1 s to 2 s may be used. A few examples are
49、given in Figures 1, 2 and 3. For cylindrical bends mandrels having radii from 0,5 mm to 5 mm, with steps of 0,5 mm, shall be used. For a 0T-bend a mandrel of radius 0,5 mm shall be used, and the resulting bend totally bent flat. The cylindrical bend method may also be used for a pass/fail decision by using an agreed mandrel. The feasibility of the test depends on the type and thickness of the substrate. During the procedure the mandrel should not de
