1、 ISO 2012 Structural adhesives Guidelines for the surface preparation of metals and plastics prior to adhesive bonding Adhsifs structuraux Lignes directrices pour la prparation de surface de mtaux et de plastiques avant le collage par adhsif INTERNATIONAL STANDARD ISO 17212 Second edition 2012-02-15
2、 Reference number ISO 17212:2012(E) ISO 17212:2012(E) ii ISO 2012 All rights reserved COPYRIGHT PROTECTED DOCUMENT ISO 2012 All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized in any form or by any means, electronic or mechanical, including phot
3、ocopying and microfilm, without permission in writing from either ISO at the address below or ISOs member body in the country of the requester. ISO copyright office Case postale 56 CH-1211 Geneva 20 Tel. + 41 22 749 01 11 Fax + 41 22 749 09 47 E-mail copyrightiso.org Web www.iso.org Published in Swi
4、tzerland ISO 17212:2012(E) ISO 2012 All rights reserved iii Contents Page Foreword iv Introduction v 1 Scope 1 1.1 General . 1 1.2 Surfaces . 1 1.3 Methods . 2 2 Normative references . 3 3 T erms and definitions . 3 4 Safety 3 5 Initial preparative techniques . 4 5.1 General . 4 5.2 Handling, cleani
5、ng and storing 4 6 Surface modification 5 6.1 Physical: Mechanical (scarification) 5 6.2 Physical: Non-mechanical 6 6.3 Chemical 6 6.4 Combined procedures . 9 7 Preparative procedures .10 7.1 General .10 7.2 Specific . 11 8 Evaluation of durability 26 ISO 17212:2012(E) Foreword ISO (the Internationa
6、l 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. Each member body interested in a subject for which a technical committee has been es
7、tablished 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 International Electrotechnical Commission (IEC) on all matters of electrotechnical standardi
8、zation. 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 Standards adopted by the technical committees are circulated to the member bodies for vot
9、ing. 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 subject of patent rights. ISO shall not be held responsible for identifying any or all suc
10、h patent rights. ISO 17212 was prepared by Technical Committee ISO/TC 61, Plastics, Subcommittee SC 11, Products. This second edition cancels and replaces the first edition (ISO 17212:2004), which has been technically revised. iv ISO 2012 All rights reserved ISO 17212:2012(E) Introduction Some mater
11、ials will bond far better than others and some will not bond at all without special treatment. The suitability of a surface for bonding depends upon the degree of surface preparation, the joints design, the function it has to perform (joining, sealing, etc.) and the environment it has to perform in.
12、 Prior to bonding, some degree of surface preparation is required for most adhesives but not all. Material surfaces that are particularly prone to weak or loose surface layers, stress cracking or solvent attack usually require special treatment. Following appropriate preparation, most common metals
13、and their alloys can be bonded satisfactorily. Were it not for contamination and residual mould release agents, thermoset plastics (e.g. polyepoxy and polyester composites) would bond well without any preparation. By contrast, most thermoplastics require careful preparation because of their low surf
14、ace energy. Some paints especially the cataphoretic, water-based primers used by the vehicle industries can provide an excellent surface for bonding. However, the stability of the interface below the paint should be checked. The surface of the paint itself, even if fresh, can require treatment in or
15、der to raise its free energy and thus facilitate wetting. Certain adhesives possess the ability to dissolve light oils and some polymeric materials. Consequently, for joints that are not “safety-critical” some surfaces do not require any preparation prior to bonding. In order to achieve the optimum
16、environmental durability from a bonded joint, the traditional preparative approach usually, though not necessarily, consisted of three sequential steps: the removal of contaminants; physically induced modification of the surface to be bonded; chemical treatment. However, legislative pressure is driv
17、ing development and the introduction of new methods. Consequently, the separate steps of the foregoing sequence are being combined and the more hazardous chemicals are being progressively eliminated. The majority of both thermoset and thermoplastics materials can be prepared by commonly applicable t
18、echniques though there will often be detailed differences. By contrast, metal and metal-alloy surfaces to be bonded generally require individual treatment. The optimization of the durability of a metal-based joint usually requires the introduction of progressively more complex and specific treatment
19、s. Such process options are described for a number of metals and their alloys, and some plastics (see Clause 7). ISO 2012 All rights reserved v Structural adhesives Guidelines for the surface preparation of metals and plastics prior to adhesive bonding 1 Scope 1.1 General This International Standard
20、 provides and describes the usual procedures for the preparation of component surfaces prior to bonding for either laboratory evaluation or the process of construction. This International Standard is applicable to metal and plastic surfaces that are commonly encountered. 1.2 Surfaces These comprise
21、the following metal, metal-alloy and plastic families the last-mentioned including filled versions and suitable paints: Metals and metal alloys aluminium chromium copper magnesium nickel steel (mild) steel (stainless) tin titanium zinc Paints cataphoretic (water-based) poly-alkyd ester epoxide ureth
22、ane INTERNATIONAL STANDARD ISO 17212:2012(E) ISO 2012 All rights reserved 1 ISO 17212:2012(E) Plastics Thermoplastic acrylonitrile-butadiene-styrene copolymer poly-acetal acrylate amide butylene terephthalate carbonate ester ether ether ketone ethylene imide methyl methacrylate phenylene oxide propy
23、lene styrene sulfone tetrafluoroethylene vinyl chloride Thermoset cellulose-based esters poly-alkyd allyl phthalate amino epoxide ester phenolic urethane urea-based (see poly-amino above) 1.3 Methods The various techniques described for cleaning and modifying surfaces are drawn from the best of curr
24、ent practice. The methods can be used in a variety of combinations to create the most effective preparative process conducive with the environmental durability required of the bonded joint. 2 ISO 2012 All rights reserved ISO 17212:2012(E) 2 Normative references The following referenced documents are
25、 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. ISO 472, Plastics Vocabulary EN 923, Adhesives Terms and definitions EN 2243-5, Aerospa
26、ce series Non-metallic materials Structural adhesives Test methods Part 5: Ageing tests 3 T erms and definitio ns For the purposes of this document, the terms and definitions in ISO 472 a n d E N 9 2 3 , t o g e t h e r w i t h t h e following, apply. 3.1 plastic material which contains, as an essen
27、tial ingredient, a high polymer and which, at some stage in its processing into finished products, can be shaped by flow NOTE 1 For the specific requirements of this International Standard, “plastic” also includes paint. In this latter context, it needs be realized that only a few paint surfaces are
28、 capable of supporting anything other than purely nominal loads. The exceptions are typically those based upon aqueous, electrochemical paints such as those used in the automotive industries and the acrylic-, epoxy- and polyester-based paints used during the preparation of “pre-coated” metal sheet.
29、NOTE 2 In some countries, the use of the term “plastics” as the singular form as well as the plural form is permitted. 3.2 s c ar i fic at ion shallow roughening of both metallic and plastic (including paint) surfaces, using either abrasion or blasting, almost invariably improving the performance of
30、 the final bonded joint 4 Safety Users of this International Standard shall be familiar with normal laboratory practice and the principles of good industrial hygiene. Users shall be aware that this International Standard does not purport to address all safety problems, and it is their responsibility
31、 to establish practices which are compliant with relevant national health, safety and environmental legislation. Concentrated acids, alkalis and oxidizing agents (e.g. chromium trioxide, dichromates and chrome-based solutions) are all highly corrosive chemicals. Splashes can cause severe damage to b
32、oth skin and eyes and will damage normal clothing. Protective clothing (e.g. overalls, gloves and goggles or visors) shall always be worn when using these chemicals. Similarly, appropriate precautions shall be taken when using solvents. At a minimum, eye protection and gloves (or appropriate barrier
33、 cream) shall be worn. Wherever possible, use propan-2-ol as a solvent. Otherwise, a ketone (acetone or methyl ethyl ketone) or, though deprecated, a halogenated solvent, that meets the requirements of the Montreal Protocol and national legislative requirements, can be used. Alcohols and ketones are
34、 flammable particularly ketones. All such materials are narcotic when concentrated. Ventilate properly, take account of vapour density and draw fumes away from the operator. Do not allow any cleaning materials to contact the skin. Abuse can lead to dermatitis. ISO 2012 All rights reserved 3 ISO 1721
35、2:2012(E) Some of the methods given below employ dangerous techniques, materials and proprietary chemicals. It is essential, therefore, that the suppliers instructions be followed, health and safety data studied, and appropriate safety procedures established. Waste and spent materials shall be dispo
36、sed of in accordance with national legislative requirements through the services of an authorized disposal organization whose advice shall always be sought. WARNING When making up solutions: NEVER POUR WATER INTO ACID. ALWAYS ADD ACID IN A SLOW, STEADY STREAM TO A STIRRED SOLUTION. An exothermic rea
37、ction can heat the resulting mixture. If this occurs, contamination hazards will be i n t e n s i fi e d . T A K E G R E A T C A R E . 5 Initial preparative techniques 5.1 General When safety-critical structures are being bonded, optimum treatment is always necessary. This requires the use of approp
38、riate techniques to both clean and modify the surface, which itself can be either an inorganic or an organic coating or even a combination of both. By contrast, when joints are only to be lightly or nominally loaded, the use of adhesives capable of dissolving light oils can allow minimal, or even no
39、, surface preparation. The manufacturers advice shall always be sought. 5.2 Handling, cleaning and storing 5.2.1 Handling Component areas which are to be bonded shall be handled as little as possible prior to preparation. After preparation, such areas should not be handled directly at all. However,
40、if this is unavoidable then clean, lint-free cotton or nylon gloves shall be worn. 5.2.2 Cleaning Remove oil- and grease-based residues using aqueous materials if possible. Non-ionic detergents give good results. Proprietary alkaline cleaners are particularly good for metals because not only can the
41、y remove hydrocarbons but the more aggressive, stronger, versions can also remove metallic soaps and salts. However, the latter shall not be used on aluminium, and care shall be taken to ensure that this metal is not exposed to cleaners based on sodium hydroxide or other alkaline materials. Some pro
42、prietary mixtures are used hot while others utilize either anodic or a cathodic currents. Whichever cleaning agent is used, components shall always be rinsed thoroughly and dried in a stream of warm, clean, dry, oil-free air for about 10 min at 60 C. If solvents need to be used to remove identificat
43、ion marks, or paint, then propan-2-ol shall be used wherever possible. Alternatively, use acetone, methyl ethyl ketone or another permitted solvent (see Clause 4). Solvents can severely damage some thermoplastic materials by either dissolving them or initiating stress cracking. Polycarbonate, poly(m
44、ethyl methacrylate) and acrylonitrile-butadiene-styrene-based plastics are particularly susceptible in this latter regard. Ultrasonic cleaning can prove acceptable for the preparation of smaller components. The use of a vapour bath is generally deprecated, but is recommended for the preparation of t
45、itanium and its alloys. However, chlorinated solvents shall not be used in this instance. It shall not be forgotten that some industrial processes can, and do, have a damaging effect on surfaces, both during and after their preparation. The use of equipment often releases deleterious dust, fumes and
46、 vapours into the air. Oil vapour, mould release agent sprays and the atmosphere of a plating shop are particularly 4 ISO 2012 All rights reserved ISO 17212:2012(E) detrimental. Consequently, surface preparation (and bonding) shall be carried out in separate areas where such contamination can be avo
47、ided. 5.2.3 Storage A distinction needs to be made between laboratory storage and the delays incurred during industrial production. The former implies performance qualification of either surface or adhesive. Where qualification is required, storage shall be maintained in an ambient atmosphere of (23
48、 2) C with a relative humidity of (50 5) %. The components shall be used within 8 h, except for those materials, such as mild steel, which are still liable to prejudicial oxidation. Such surfaces shall be bonded as soon as possible after preparation and, prior to bonding, shall always be maintained
49、in a dry atmosphere. Wherever practical, parts shall not be touched and shall be kept in a closed container or under a suitable non-contaminating cover, such as unbleached Kraft paper. Industrial production requires that minimum performance standards be maintained. To this end, procedures shall be established such that the integrity of a prepared surface is not unacceptably prejudiced prior to assembly. Particular regard shall be paid to the possibility of damage occurring through oxidation, c
