1、BRITISH STANDARD Adhesives for load-bearing timber structures - Casein adhesives - Classification and performance requirements The European Standard EN 12436:2001 has the status of a British Standard ICs 83.180; 91.100 BS EN 12436:2002 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIG
2、HT LAW BS EN 12436:2002 Amd.No. National foreword Date Comments This British Standard, having been prepared under the direction of the Sector Policy and Strategy Committee for Materials and Chemicals, was published under the authority of the Standards Policy and Strategy Committee on 28 January 2002
3、 This British Standard is the official English language version of EN 12436:2001. The UK participation in its preparation was entrusted to Technical Committee PRI/52, Adhesives, which has the responsibility to: - - aid enquirers to understand the text; present to the responsible European committee a
4、ny enquiries on the interpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. - A list of organizations represented on this committee can be obtained on request to its secretary. Cross-reference
5、s The British Standards which implement international or European publications referred to in this document may be found in the BSI Standards Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Find” facility of the BSI Standards Electronic Catalogue
6、. A British Standard does not purport to include all the necessary provisions of a contract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprise
7、s a front cover, an inside front cover, the EN title page, pages 2 to 12, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. O BSI 28 January 2002 ISBN O 580 38910 3 EUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM E
8、N 12436 November 2001 ICs 83.1 80 English version Ad hesives for load-bearing timber structures - Casein ad hesives - Classification and petformance requirements Colles pour structures portantes en bois - Colles casine - Classification et exigences de performance Klebstoffe fr tragende Holzbauteile
9、- Kaseinklebstoffe - Klassifizierung und Leistungsanforderungen This European Standard was approved by CEN on 30 September 2001 CEN members are bound to comply with the CENKENELEC Internal Regulations which stipulate the conditions for giving this European Standard the status of a national standard
10、without any alteration. Up-to-date lists and bibliographical references concerning such national standards may be obtained on application to the Management Centre or to any CEN member. This European Standard exists in three official versions (English, French, German). A version in any other language
11、 made by translation under the responsibility of a CEN member into its own language and notified to the Management Centre has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Icelan
12、d, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION EUROPISCHES KOMITEE FR NORMUNG COMIT EUROPEN DE NORMALISATION Management Centre: rue de Stassart, 36 B-1050 Brussels O 2001 CEN All rights of exploitati
13、on in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12436:2001 E EN 12436:2001 (E) Contents Page 1 Scope . 2 Normative references 3 Terms and definitions . .4 4 Safety . 4 5 Climatic conditions . 6 Requirements . 6.1 General 6.2 Resistance to shear forces 7 Test
14、report . Annex A (normative) Type and duration of exposure cycles . 7 Annex B (normative) Test methods for the determination of the resistance of casein 8 adhesive films to mould growth . 2 EN 12436:2001 (E) Foreword This European Standard has been prepared by Technical Committee CEN/TC 193, Adhesiv
15、es, the Secretariat of which is held by AENOR. 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 May 2002, and conflicting national standards shall be withdrawn at the latest by May 2002. This stand
16、ard gives performance requirements and test methods for casein adhesives, where they are permitted, for use under indoor conditions. It supplements EN 301 and should be used in conjunction with EN 302-1. The standard contains two normative annexes, Annex A giving details of exposure cycles used befo
17、re testing the loads and Annex B describing test methods for the determination of the resistance of the adhesive to mould growth. According to the CENKENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria,
18、Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom. 3 EN 12436:2001 (E) 1 Scope This European Standard specifies performance requirements and the appropriate test me
19、thods for casein adhesives for the manufacture of load-bearing wooden structures for use under indoor conditions in heated and ventilated buildings. This standard is not applicable to casein adhesives used for bonding woods with a density exceeding 750 kg/m3. 2 Normative references This European Sta
20、ndard incorporates, by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text, and the publications are listed hereafter. For dated references, subsequent amendments to or revisions of any of these publications apply
21、 to this European Standard only when incorporated in it by amendment or revision. For undated references the latest edition of the publication referred to applies (including amendments). EN 30 1 , Adhesives, phenolic and aminoplasfic, for load-bearing fimber sfrucfures - Classificafion and performan
22、ce requiremenfs. EN 302-1, Adhesives for load-bearing fimber sfrucfures - Polycondensafion adhesives of fhe phenolic and aminoplasfic types - Tesf mefhods - Par 1: Deferminafion of bond sfrengfh in longifudinal shear. EN 923, Adhesives - Terms and definifions. 3 Terms and definitions For the purpose
23、s of this European Standard the terms and definitions given in EN 923 and the following apply. 3.1 casein protein precipitated from skimmed milk which, when compounded with other reactants, is used as an adhesive for wood NOTE Adapted from EN 923. 4 Safety Persons using this standard shall familiar
24、with normal laboratory practice. This standard does not purport to address all the safety problems, if any, associated with its use. It is the responsibility of the user to establish safety and health practices and to ensure compliance with any European or national regulatory conditions. 5 Climatic
25、conditions Casein adhesives are suitable for use at temperatures not exceeding 50 OC and under climatic conditions of use, equivalent to 85 % relative humidity at 20 OC, that result in a moisture content in softwoods and most hardwoods of 20 %, and somewhat lower in wood-based panels. 4 EN 12436:200
26、1 (E) Treatment (see Annex A) A. 1 A.2 A.3 6 Requirements Minimum failing load N Close contact joints Gap joints 2 O00 1600 1200 1 O00 1600 1300 6.1 General 6.1.1 The adhesive shall be supplied in the form of a dry powder, of which a minimum of 50 % shall be casein. When prepared with water only, in
27、 accordance with the manufacturers instructions, it shall yield a homogenous liquid, free from grit, and of a consistency suitable for spreading. 6.1.2 The adhesive powder shall contain a preservative in an amount that has been proved to protect against mould contamination when tested in accordance
28、with Annex B. 6.1.3 All adhesives shall be tested by the shear test (see 6.2) using bonded test specimens made from beech. Preparation and testing of the bonded test specimens shall be carried out in accordance with EN 302-1. If the adhesive is specifically claimed to be suitable for use with partic
29、ular hardwood species, it shall also be tested on bonded test specimens made from that or those species. 6.2 Resistance to shear forces The shear failing load of close contact and gap joints after the three conditioning treatments specified in Annex A shall be tested in accordance with EN 302-1 exce
30、pt that the test report shall be as given in clause 7 of this standard. a) Joints made with beechwood The strength of joints shall be as given in Table 1 Table 1 -Minimum failing loads for close contact joints (0,l mm) and gap joints (1 mm f 0,l mm) on beechwood b) Joints made on other hardwood spec
31、ies If the adhesive is tested on other hardwood species (see 6.1.3) with a density not exceeding 750 kg/m3, the strength of joints shall be as given in Table 1. 5 EN 12436:2001 (E) 7 Test report The following items shall be recorded in the test report: a) The adhesive: 1) type and origin of the adhe
32、sive; 2) batch number of the adhesive used; 3) number of components and method of preparation. b) Preparation of the samples and testing procedure: 1) wood density expressed in kilograms per cubic metre at 12 % moisture content; 2) special treatment of the surface of the panels to be bonded; 3) the
33、method of making the bond (.e. temperature, pressure and duration); 4) time elapsed between the bonding and the preparation of test specimens; 5) number of test specimens; 6) conditioning cycles applied designation (treatment code from Annex A); 7) precise identification of the microorganisms used a
34、nd whether single cultures or a mixed culture was used; 8) the rate of application of force. c) Test results: 1) mean force at failure expressed in kilonewtons and rounded to the nearest 0,l kN; 2) minimum value of the breaking force observed for any valid result; 3) standard deviation expressed in
35、kilonewtons; 4) coefficient of variation expressed in %; 5) type of failure; 6) estimate of the proportion of the tested surface covered by wood fibre (to the nearest 10 %) expressed as the mean value for all valid test results; 7) date of the test; 8) any other factors that may have affected the re
36、sults. 6 EN 12436:2001 (E) Annex A ( no rm a t ive) Type and duration of exposure cycles Test specimens shall be subjected to the appropriate treatments given in Table A.1. Table A.l -Type and duration of exposure cycles humidity of (65 f 5) %. of (85 f 5) %. The humid atmosphere 20/85 is defined as
37、 a temperature of (20 f 2) OC and a relative humidity 7 EN 12436:2001 (E) Annex B ( no rm a t ive) Test methods for the determination of the resistance of casein adhesive films to mould growth B.l Scope This annex specifies methods of determining the effect of mould contamination on casein adhesive
38、films, by exposure to cultures of selected species of mould grown on agar plates. WARNING The following procedures use microorganisms that can constitute a health hazard. It is essential that these tests be carried out in properly equipped microbiological laboratories by appropriately trained person
39、nel. B.2 Principle The tests for resistance of adhesive films to mould attack provide an indication of whether the adhesive will carry into the glue line sufficient anti-mould properties to prevent attack by moulds that occur naturally in wood. B.3 Apparatus B.3.1 Anfibiofic sensifivify disks), 13 m
40、m in diameter. B.3.2 Cylinder, 500 ml capacify, graduated in 5 ml subdivisions. B.3.3 Consfanf femperafure chamber, capable of being maintained at (28 f 0,5) OC or (25 f 0,5) OC, or two chambers, if needed simultaneously. B.3.4 Desiccafors, two, about 250 mm in inside diameter and 200 mm in height,
41、with perforated porcelain plates to support the culture plates. B.3.5 Glass rods, approximately 300 mm in length, having a diameter of approximately 6 mm. B.3.6 Glass rod, L-shaped, having the same dimensions as those in B.3.5, bent into an L at approximately 70 mm. B.3.7 Jar, round, approximately 1
42、50 mm in height by 90 mm in inside diameter. B.3.8 Pefri dishes, with lid, with approximate dimensions of 100 mm diameter and height 15 mm, either sterilizable glass or pre-sterilized. B.3.9 Pipeftes, sterile, disposable, capable of delivering 0,l ml, 1 ml, or 3 ml; or a 3 ml pipette, borosilicate,
43、graduated in 0,l ml subdivisions. ) An example of a suitable type is code no. 1571-33-8 supplied by Difco Laboratories Ltd. P.O. Box 14 B, Central Avenue, East Molesey, Surrey KT8 OSE. This information is given for the convenience of users of this European Standard and does not constitute an endorse
44、ment by CEN of the product named. 8 EN 12436:2001 (E) B.3.1 O Plafinum loop. B.3.11 Sferile or sferilizable screw cap boffles and caps, having a capacity of approximately 250 ml.) B.3.12 Borosilicafe fesf fubes, approximately 150 mm in length and 20 mm in diameter, with screw caps with cemented rubb
45、er liners, capable of withstanding repeated steam pressure sterilization at 121 OC or 103 kPa for 20 min periods. B.3.13 Thermomefer, covering the range from -2 OC to +68 OC with a measuring uncertainty of I1 OC. B.3.14 Sferilizer (aufoclave), having a 103 kPa minimum exit steam pressure. B.4 Materi
46、als B.4.1 Pofafo-dexfrose agarP3) B.4.2 Tarfaric acid, (sterile 10 % solution). B.4.3 Sferile wafer. B.4.4 Diocfyl sodium sulfouccinafe.) B.5 Precautions These test methods employ live cultures of mould. Use proper microbiological procedures in order to prevent contamination of the equipment and the
47、 work area. Also, ensure that biologically aseptic conditions prevail throughout the preparation of the inoculae and the conduct of the tests. To avoid contamination of the adhesive sample and control, ensure that all apparatus coming into direct contact with them is sterile. In addition, clean and
48、sterilize all spills and all equipment coming into contact with the cultures and the inoculated adhesive test specimens. Media not necessarily designed for pathogens may support their growth so that great care is needed for the handling and disposal of all cultures and media. Sterilize all cultures
49、by autoclaving, and sterilize or disinfect associated apparatus and materials before disposal or re-use. B.6 Test organisms B.6.1 Cultures of the following species are used? a) Aspergillus nigerv. Tiegh (ATCC No. 6277 or IMI No. 045 - 551). b) Aspergillus flavus (ATCC No. 9643 or IMI No. O91 - 856). c) Penicillium lufeum (ATCC No. 9644). ) The type known as “universal bottles” (sterilizable glass), Kilnerjars or sterile plastics universal bottles are suitable. This information is given for the convenience of users of this European Standard and does not constitute an endor
