BS-EN-205-1991.pdf
BRITISH STANDARD BS EN 205: 1991 Test methods for wood adhesives for non-structural applications Determination of tensile shear strength of lap joints This European Standard EN 205:1991 has the status of a British Standard Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 205:1991 This British Standard was published under the authority of the Standards Board and comes into effect on 29 November 1991 © BSI 09-1999 The following BSI references relate to the work on this standard: Committee reference ADC/6 Draft for comment 83/53890 DC ISBN 0 580 20050 7 Cooperating organizations The European Committee for Standardization, under whose supervision this European Standard was prepared, comprises the national standards organizations of the following Western European countries. AustriaOesterreichisches Normungsinstitut BelgiumInstitut belge de normalisation DenmarkDansk Standardiseringsraad FinlandSuomen Standardisoimisliito, r.y. FranceAssociation française de normalisation GermanyDeutsches Institut für Normung e.V. GreeceHellenic Organization for Standardization IcelandTechnological Institute of Iceland IrelandNational Standards Authority of Ireland ItalyEnte Nazionale Italiano di Unificazione LuxembourgInspection du Travail et des Mines NetherlandsNederlands Normalisatie-instituut NorwayNorges Standardiseringsforbund PortugalInstituto Portuguès da Qualidade SpainAsociación Española de Normalización y Certificación SwedenStandardiseringskommissionen i Sverige SwitzerlandAssociation suisse de normalisation United KingdomBritish Standards Institution Amendments issued since publication Amd. No.DateComments Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 205:1991 © BSI 09-1999i Contents Page Cooperating organizationsInside front cover National forewordii Foreword2 Text of EN 2053 National appendix NA (informative)Inside back cover National appendix NB (informative)Inside back cover Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI BS EN 205:1991 ii © BSI 09-1999 National foreword This British Standard has been prepared under the direction of the Adhesives Standards Policy Committee and is the English language version of EN 205:1991, published by the European Committee for Standardization (CEN). It supersedes clause 4 of BS 3544:1962 which is deleted by amendment, and DD 74:1981 which is withdrawn. EN 205 was produced as a result of international discussions in which the United kingdom took an active part. EN 205:1991 has been approved by CEN Member Bodies under the weighted voting procedures introduced in 1988 to coincide with the introduction of “New Approach” Directives from the Commission of the European Community. 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 comprises a front cover, an inside front cover, pages i and ii, the EN title page, pages 2 to 8, an inside back cover and a back cover. This standard has been updated (see copyright date) and may have had amendments incorporated. This will be indicated in the amendment table on the inside front cover. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EUROPEAN STANDARD NORME EUROPÉENNE EUROPÄISCHE NORM EN 205 May 1991 UDC 665.93:674:691.11:692.241.3:692.8.:684:620.179.4:620.172 Descriptors: Adhesive, wood, wood products, bonding, choice, dimensions, dimensional tolerances, test pieces, tests, tensile tests, shear tests, test atmospheres, determination, adhesive strength, results English version Test methods for wood adhesives for non-structural applications Determination of tensile shear strength of lap joints Méthodes dessai des colles pour bois à usages non structuraux Détermination du pouvoir adhésif des collages longitudinaux par lessai de cisaillement Präfverfahren für Holzklebstoffe für nichttragende Bauteile Bestimmung der Klebfestigkeit von Längsklebungen im Zugversuch This European Standard was approved by CEN on 20 May 1991. 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 standards 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 translation under the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the official versions. CEN members are the national standards bodies of Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. CEN European Committee for Standardization Comité Européen de Normalisation Europäisches Komitee für Normung Central Secretariat: rue de Stassart 36, B-1050 Brussels © CEN 1991 Copyright reserved to all CEN members Ref. No. EN 205:1991 E Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 205:1991 2 © BSI 09-1999 Foreword This European Standard has been prepared by the Technical Committee CEN/TC 103 “Adhesives for wood and derived timber products”. In accordance with the Common CEN/CENELEC Rules, the following countries are bound to implement this European Standard: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, Switzerland and United Kingdom. Contents Page Foreword2 Introduction3 1Scope3 2Normative references3 3Joint components3 4Test pieces6 5Conditioning and number of test pieces6 6Tensile shear test7 7Expression of results7 8Test report7 Annex A (informative) Single lap test pieces8 Figure 1 Partition and marking of the bonded assemblies (lap joints) in for example 5 × 4 individual test pieces (1a 1d to 5a 5d)5 Figure 2 Lap joint test piece with thin bond line6 Figure 3 Lap joint test piece with thick bond line (angle between growth ring surfaces and surfaces to be bonded = 30° to 90°)6 Figure 4 Lap joint test piece for in-house test (single lap test piece for tensile shear test)8 Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 205:1991 © BSI 09-19993 Introduction European Standards giving test methods and a common classification with respect to durability classes for wood adhesives will allow considerable improvement in consumer protection and provide greater legal security in any future product liability system with regard to properties guaranteed by the adhesive manufacturer. NOTESee also: ISO 6237:1987, Adhesives Wood-to-wood adhesive bonds Determination of shear strength by tensile loading. ISO 6238:1987, Adhesives Wood-to-wood adhesive bonds Determination of shear strength by compression loading. 1 Scope This European Standard describes tests for adhesives for wood and derived timber products for the assessment of their resistance to various physical effects. It does not apply to adhesives for structural use nor to the manufacture of particle boards, fibreboards, and plywood. It does not replace specific tests or tests on finished products. The method described in this standard is suitable for the following and other applications: assessing the usability and quality of adhesives for wood and derived timber products; classifying these adhesives into the durability classes D1 to D4 of EN 204; assessing effects on the bond strength resulting from the bonding conditions chosen, the various conditioning sequences and the treatment of the test pieces before and after bonding; assessing the bond strength of bonds with thin or thick bond line. 2 Normative references This European Standard 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 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. EN 204, Evaluation of non-structural adhesives for joining of wood and derived timber products. ISO 554, Standard atmospheres for conditioning and/or testing Specifications. 3 Joint components 3.1 Selection of wood Prepare two unsteamed, planed, straight-grained beech boards1) (fagus sylvatica L) 130 mm wide (see Figure 1) one 5 mm thick, the other (5 + a) mm where “a” is the thickness of the bond line. For a thin bond line (a . 0,1 mm) use 2 boards of 5 mm thickness. The minimum density of the wood fagus sylvatica L. shall be (700 ± 100) kg/m3 when measured on wood having a moisture content of 12 %. The wood shall be conditioned in accordance with ISO 554: (23 ± 2) °C/(50 ± 5) relative humidity or (20 ± 2) °C/(65 ± 5) relative humidity. The length of the panels shall be a multiple of . 300 mm, for example . 600 mm, and the angle between the growth ring surfaces and the surfaces to be bonded shall be between 30° and 90°. Limit deviations in thickness: ± 0,1 mm. If the behaviour of an adhesive applied in a thick bond line is to be compared with its behaviour when applied in a thin bond line care shall be taken that the beech boards for both types of bond are cut from the same piece in the direction of the grain and one directly after the other. To achieve this, cut the boards in the following order: a 5 mm strip for testing the thin bond line, followed by a 5 mm strip for testing the thick bond line, followed by a 5 mm strip for testing the thin bond line, followed by a (5 + a) mm strip for testing the thick bond line. 1) When using other species of wood, special agreements are required. For a list of suitable species of wood, see Annex B of ISO 6238. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 205:1991 4 © BSI 09-1999 3.2 Bonding of the joint components The bonding conditions specified by the adhesive manufacturer shall be used. Prepare boards for use with a thin bond line, and, if the adhesive manufacturer specifies it, also for use with thick bond lines of 0,5 mm or 1,0 mm as required. 3.2.1 Thin bond lines Bond two 5 mm thick beech boards as shown in Figure 2, with the grains running in the same direction. Distribute the pressure uniformly over the bonding surface so that 10 mm thick bonded assemblies are formed. Comply with the processing requirements specified by the adhesive manufacturer, including whether the adhesive is applied to one or both sides, the specific quantity to be applied the open and closed assembly time and the pressing conditions. The pressure applied shall be in accordance with the adhesive manufacturers instructions and/or information contained in quality standards. Immediately before bonding, prepare the wooden surfaces to be bonded by either planing (the preferred method) or with abrasive paper of grain size 150 complying with the FEPA standard2). Do not touch or soil the prepared surface. Indicate on the test report if the surface has been treated in a different way. 2) Fédération européenne des fabricants de produits abrasifs; the FEPA-Standard 43:1984 is available from: British Abrasive Federation, Fair Green House, Sawbridgeworth, Herts OM21 9AJ Fachverband Elektrokorund- und Siliziumkarbid-Hersteller e.V. (FES), Karlstraße 21, 0-6000 Frankfurt 1. Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 205:1991 © BSI 09-19995 Figure 1 Partition and marking of the bonded assemblies (lap joints) in for example 5 × 4 individual test pieces (1a 1d to 5a 5d) Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 205:1991 6 © BSI 09-1999 3.2.2 Thick bond lines Such tests are carried out in order to test the behaviour of adhesives in thick bond lines, which might be caused by poor fit or by surface irregularities arising from processing techniques. As can be seen from Figure 1 and Figure 3, the (5 + a) mm thick board is provided with grooves of depth a = 0,5 mm or a = 1 mm and width about approximately 14 mm. Apply the adhesive to the grooved board and work it well into the grooves so that they are completely filled allowing for squeezeout. Bond (5 + a) mm thick grooved boards to 5 mm thick ungrooved boards to obtain (10 + a) mm thick bonded assemblies for the preparation of the test pieces. 4 Test pieces Take five pieces with a width of b = 20 mm from the bonded assemblies according to the location of the cuts as indicated in Figure 1 after removing the long edges and identify for example by serial numbers from 1 to 5. After identification (see Figure 1) divide into test pieces with a length of l1 = 150 mm. Make saw cuts in the test assemblies symmetrically about the centre of the lap as shown in Figure 3. This defines a test surface l2 = 10 mm length. Take care that the cuts completely cut through the bonding surface of the samples. As thin adhesive joints are only a few hundredths of a millimetre thick, take care that the cuts only penetrate as little as possible into the other part of the joint. 5 Conditioning and number of test pieces After bonding the test pieces, condition them. The nature and duration of this conditioning depend on the requirements to be met by the adhesive. The sequences of conditioning are given in Table 2 of EN 204. µ=angle between growth ring surfaces and surface to be bonded = 30° up to 90° b=width of test piece (width of test surface)= ( 20 ± 0,1) mm l1=total length of test piece= (150 ± 1) mm l2=length of overlap (length of test surface) = (10 ± 0,1) mm s =thickness of jointing parts= (5 ± 0,1) mm Figure 2 Lap joint test piece with thin bond line Figure 3 Lap joint test piece with thick bond line (angle between growth ring surfaces and surfaces to be bonded = 30° to 90°) Licensed Copy: sheffieldun sheffieldun, na, Fri Nov 03 09:23:36 GMT+00:00 2006, Uncontrolled Copy, (c) BSI EN 205:1991 © BSI 09-19997 At least 20 test pieces are required for any conditioning or conditioning sequence for each strength test. Test the test pieces immediately after the ending of the last conditioning to avoid further changes in the moisture content. 6 Tensile shear test At least 1 week shall p
