1、BRITISH STANDARD BS EN 12436:2002 The European Standard EN 12436:2001 has the status of a British Standard ICS 83.180; 91.100 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 12436:2002 This British Standard, having been prepared under the direction of the Sector Policy an
2、d Strategy Committee for Materials and Chemicals, was published under the authority of the Standards Policy and Strategy Committee on 28 January 2002 BSI 28 January 2002 ISBN 0 580 38910 3 National foreword This British Standard is the official English language version of EN 12436:2001. The UK parti
3、cipation in its preparation was entrusted to Technical Committee PRI/52, Adhesives, which has the responsibility to: A list of organizations represented on this committee can be obtained on request to its secretary. Cross-references The British Standards which implement international or European pub
4、lications 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. A British Standard does not purport to include all the necessary pr
5、ovisions 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. aid enquirers to understand the text; present to the responsible European committee any enquiries on the int
6、erpretation, or proposals for change, and keep the UK interests informed; monitor related international and European developments and promulgate them in the UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title page, pages 2 to 12, an inside back cover and a
7、 back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEAN STANDARD NORME EUROPENNE EUROPISCHE NORM EN 12436 November 2001 ICS 83.180 English version Adhesives for load-bearing timber
8、structures Casein adhesives Classification and performance requirements Colles pour structures portantes en bois Colles casine Classification et exigences de performance Klebstoffe fr tragende Holzbauteile Kaseinklebstoffe Klassifizierung und Leistungsanforderungen This European Standard was approve
9、d by CEN on 30 September 2001. 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 national
10、 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 made by translation under the responsibility of a CEN member into its own language and notified
11、 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, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and Uni
12、ted Kingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG Management Centre: rue de Stassart, 36 B-1050 Brussels 2001 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members. Ref. No. EN 12436:200
13、1 EEN 12436:2001 (E) 2 Contents Page 1 Scope .4 2 Normative references.4 3 Terms and definitions 4 4 Safety .4 5 Climatic conditions.4 6 Requirements5 6.1 General.5 6.2 Resistance to shear forces.5 7 Test report.6 Annex A (normative) Type and duration of exposure cycles .7 Annex B (normative) Test m
14、ethods for the determination of the resistance of casein adhesive films to mould growth.8EN 12436:2001 (E) 3 Foreword This European Standard has been prepared by Technical Committee CEN/TC 193, Adhesives, the Secretariat of which is held by AENOR. This European Standard shall be given the status of
15、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 standard gives performance requirements and test methods for casein adhesives, where they are permitted,
16、 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 before testing the loads and Annex B describing test methods for the determination of the resistance of
17、 the adhesive to mould growth. According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Czech Republic, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxem
18、bourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and the United Kingdom.EN 12436:2001 (E) 4 1 Scope This European Standard specifies performance requirements and the appropriate test methods for casein adhesives for the manufacture of load-bearing wooden structures for use under indo
19、or conditions in heated and ventilated buildings. This standard is not applicable to casein adhesives used for bonding woods with a density exceeding 750 kg/m 3 . 2 Normative references This European Standard incorporates, by dated or undated reference, provisions from other publications. These norm
20、ative 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 to this European Standard only when incorporated in it by amendment or revision. For undated ref
21、erences the latest edition of the publication referred to applies (including amendments). EN 301, Adhesives, phenolic and aminoplastic, for load-bearing timber structures Classification and performance requirements. EN 302-1, Adhesives for load-bearing timber structures Polycondensation adhesives of
22、 the phenolic and aminoplastic types Test methods Part 1: Determination of bond strength in longitudinal shear. EN 923, Adhesives Terms and definitions. 3 Terms and definitions For the purposes of this European Standard the terms and definitions given in EN 923 and the following apply. 3.1 casein pr
23、otein 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 with normal laboratory practice. This standard does not purport to address all the safety problems, if any,
24、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 conditions Casein adhesives are suitable for use at temperatures not exceeding 50 C and under climatic condi
25、tions of use, equivalent to 85 % relative humidity at 20 C, that result in a moisture content in softwoods and most hardwoods of 20 %, and somewhat lower in wood-based panels.EN 12436:2001 (E) 5 6 Requirements 6.1 General 6.1.1 The adhesive shall be supplied in the form of a dry powder, of which a m
26、inimum of 50 % shall be casein. When prepared with water only, in 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
27、to protect against mould contamination when tested in accordance 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 ad
28、hesive is specifically claimed to be suitable for use with particular 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 spec
29、ified in Annex A shall be tested in accordance with EN 302-1 except 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 (0,1 mm) and gap joints (
30、1 mm 0,1 mm) on beechwood Treatment (see Annex A) Minimum failing load N Close contact joints Gap joints A.1 2 000 1 600 A.2 1 200 1 000 A.3 1 600 1 300 b) Joints made on other hardwood species If the adhesive is tested on other hardwood species (see 6.1.3) with a density not exceeding 750 kg/m 3 ,
31、the strength of joints shall be as given in Table 1.EN 12436:2001 (E) 6 7 Test report The following items shall be recorded in the test report: a) The adhesive: 1) type and origin of the adhesive; 2) batch number of the adhesive used; 3) number of components and method of preparation. b) Preparation
32、 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 method of making the bond (i.e. temperature, pressure and duration); 4) time elapsed between the bonding and
33、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 and whether single cultures or a mixed culture was used; 8) the rate of application of force. c) Test results
34、: 1) mean force at failure expressed in kilonewtons and rounded to the nearest 0,1 kN; 2) minimum value of the breaking force observed for any valid result; 3) standard deviation expressed in kilonewtons; 4) coefficient of variation expressed in %; 5) type of failure; 6) estimate of the proportion o
35、f 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 results.EN 12436:2001 (E) 7 Annex A (normative) Type and duration of exposure cycles Test specimens shall be s
36、ubjected to the appropriate treatments given in Table A.1. Table A.1 Type and duration of exposure cycles Designation Treatment A1 7 days in standard atmosphere 20/65 1) A2 7 days in standard atmosphere 20/65 1) 7 days in humid atmosphere 20/85 2) Test specimens removed from the conditioning chamber
37、, one by one, and tested immediately after removal. A3 7 days in standard atmosphere 20/65 1) 7 days in humid atmosphere 20/85 2) 7 days in standard atmosphere 20/65 1) Test specimens tested in the dry state 1)The standard atmosphere, 20/65, is defined as a temperature of (20 2) C and a relative hum
38、idity of (65 5) %. 2)The humid atmosphere 20/85 is defined as a temperature of (20 2) C and a relative humidity of (85 5) %.EN 12436:2001 (E) 8 Annex B (normative) Test methods for the determination of the resistance of casein adhesive films to mould growth B.1 Scope This annex specifies methods of
39、determining the effect of mould contamination on casein adhesive 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 equi
40、pped microbiological laboratories by appropriately trained personnel. 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
41、 in wood. B.3 Apparatus B.3.1 Antibiotic sensitivity disks 1) , 13 mm in diameter. B.3.2 Cylinder, 500 ml capacity, graduated in 5 ml subdivisions. B.3.3 Constant temperature chamber, capable of being maintained at (28 0,5) C or (25 0,5) C, or two chambers, if needed simultaneously. B.3.4 Desiccator
42、s, two, about 250 mm in inside diameter and 200 mm in height, 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
43、an L at approximately 70 mm. B.3.7 Jar, round, approximately 150 mm in height by 90 mm in inside diameter. B.3.8 Petri dishes, with lid, with approximate dimensions of 100 mm diameter and height 15 mm, either sterilizable glass or pre-sterilized. B.3.9 Pipettes, sterile, disposable, capable of deliv
44、ering 0,1 ml, 1 ml, or 3 ml; or a 3 ml pipette, borosilicate, graduated in 0,1 ml subdivisions.1)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 0SE. This information is given for the convenience of users
45、 of this European Standard and does not constitute an endorsement by CEN of the product named.EN 12436:2001 (E) 9 B.3.10 Platinum loop. B.3.11 Sterile or sterilizable screw cap bottles and caps, having a capacity of approximately 250 ml. 2) B.3.12 Borosilicate test tubes, approximately 150 mm in len
46、gth and 20 mm in diameter, with screw caps with cemented rubber liners, capable of withstanding repeated steam pressure sterilization at 121 C or 103 kPa for 20 min periods. B.3.13 Thermometer, covering the range from 2 C to +68 C with a measuring uncertainty of 1 C. B.3.14 Sterilizer (autoclave), h
47、aving a 103 kPa minimum exit steam pressure. B.4 Materials B.4.1 Potato-dextrose agar. 3) B.4.2 Tartaric acid, (sterile 10 % solution). B.4.3 Sterile water. B.4.4 Dioctyl sodium sulfosuccinate. 4) B.5 Precautions These test methods employ live cultures of mould. Use proper microbiological procedures
48、 in order to prevent contamination of the equipment and the 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 d
49、irect contact with them is sterile. In addition, clean and 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 by autoclaving, and sterilize or disinfect associated apparatus and materials before disposal or re-use. B.6 Test organisms B.6.1 Cultures of th
