BS EN 00318-2002

BRITISH STANDARD BS EN 3182002 Wood based panels Determination of dimensional changes associated with changes in relative humidity The European Standard EN 3182002 has the status of a British Standard ICS 79.060.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 3182002 This British Standard, having been prepared under the direction of the Building and Civil Engineering Sector Policy and Strategy Committee, was published under the authority of the Standards Policy and Strategy Committee on 11 April 2002 BSI 11 April 2002 ISBN 0 580 39492 1 National foreword This British Standard is the official English language version of EN 3182002. It supersedes BS EN 3181993 which is withdrawn. The UK participation in its preparation was entrusted to Technical Committee B/541, Wood based panels, 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 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. 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. aid enquirers to understand the text; present to the responsible European committee any enquiries on the interpretation, or proposals for change, and keep the UK interests ined; 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 8, an inside back cover and a back cover. The BSI copyright date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN318 March2002 ICS79.060.01 SupersedesEN3181993 Englishversion WoodbasedpanelsDeterminationofdimensionalchanges associatedwithchangesinrelativehumidity PanneauxbasedeboisDterminationdesvariations dimensionnellessouslinfluencedevariationsdelhumidit relative HolzwerkstoffeBestimmungvonManderungenin VerbindungmitnderungenderrelativenLuftfeuchte ThisEuropeanStandardwasapprovedbyCENon24February2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversionsEnglish,French,German.Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentreruedeStassart,36B1050Brussels 2002CEN Allrightsofexploitationinanyandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN3182002EEN3182002E 2 Contents page Foreword3 1 Scope 4 2 Normativereferences 4 3 Principle4 4 Apparatus .4 4.1 Balance .4 4.2 Measuringinstrumentsforlengthandthickness .4 4.3 Calibrationbar. .4 4.4 Climatechamber . .4 4.5 Dryingcabinet 5 4.6 Hygrometer.5 4.7 Thermometer 5 5 Testpieces. .5 6 Procedure .5 6.1 Testpiecepreparation .5 6.1.1 General5 6.1.2 Thicknessmeasuringpoints 5 6.1.3 Lengthmeasuringpoints. .5 6.2 Conditioning.6 6.3 Measurements6 6.4 Drying7 7 Expressionofresults . .7 7.1 Moisturecontent 7 7.2 Changeinlength 7 7.3 Changeinthickness . .7 7.4 Panelresults. 8 8 Testreport . .8EN3182002E 3 Foreword ThisdocumentEN3182002hasbeenpreparedbyTechnicalCommitteeCEN/TC112“Woodbasedpanels“,the secretariatofwhichisheldbyDIN. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbySeptember2002,andconflictingnationalstandardsshallbewithdrawnatthelat estbySeptember2002. ThisdocumentsupersedesEN3181993. ComparedtotheversionEN3181993thefollowingmodificationshavebeenmade a Thescopehasbeenextendedfromfibreboardstowoodbasedpanels b Theconditioningprocedurehasbeenmodified AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowingcoun triesareboundtoimplementthisEuropeanStandardAustria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Swe den,SwitzerlandandtheUnitedKingdom.EN3182002E 4 1Scope ThisEuropeanStandardspecifiesaforthedeterminationofdimensionalchangesinwoodbasedpanels, duetochangesintherelativehumidityoftheair. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriateplacesinthetext,andthepublicationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoappliesincludingamendments. EN322, WoodbasedpanelsDeterminationofmoisturecontent. EN3261, WoodbasedpanelsSampling,cuttingandinspectionPart1Samplingandcuttingoftestpieces andexpressionoftestresults. 3Principle Becausevariationsinrelativehumidityaffectthemoisturecontentofapanelandresultinchangestoitsdimen sions,testpiecesaremeasuredafterconditioningtodifferentlevelsofrelativehumidity. Theequilibriummoisturecontentofpanelproductsisdependentonthehistoryofmoisturechange.Higherequilibrium moisturecontentsforanyonerelativehumidityareachievedindesorptioncomparedwithadsorption;thisgivesriseto ahysteresiseffect. Inordertoobtainthetruedimensionalchange,thisismeasuredbetween65relativehumidityand85relative humidityinadsorptionand65relativehumidityand30relativehumidityindesorption. 4Apparatus 4.1Balance BalanceasdescribedinEN322. 4.2 Measuringinstrumentsforlengthandthickness Instrumentseasuringlengthandthicknesswithanaccuracyof0,01mm.Anexampleofalengthmeasuring equipmentisshowninFigure1. 4.3 Calibrationbar Corrosionresistantmetalbarofsufficientlengthandshapetocalibratethelengthmeasuringequipment.Thelength ofthecalibrationbarshallbeknowntowithin0,01mm. 4.4 Climatechamber Climatechamberscapableofmaintainingtherequiredtemperatureto1Candrelativehumidityto3.EN3182002E 5 Figure1Exampleoflengthmeasuringequipment 4.5 Dryingcabinet Ventilateddryingoven,capableofbeingcontrolledat1032C. 4.6Hygrometer Hygrometerwithanaccuracyof1relativehumiditytomeasureandrecordtherelativeairhumidityintheclimate chamber. 4.7Thermometer Thermometerwithanaccuracyof0,5Ctomeasureandrecordtemperatureintheclimatechamber. 5 Testpieces Thenormaldimensionsoftestpiecesare3002mm 502mm tpanelthicknessbutlongertestpiecesmay beused.Fromeachpanel,twosetsoffourtestpiecesshallbecutineachpaneldirectiontogive16testpiecesper panelintotal.ThegeneralconditionsforsamplingofthetestpiecesshallbeinaccordancewithEN3261. 6Procedure 6.1 Testpiecepreparation 6.1.1General Thetestpiecesshallbepreparedwithsuitablemarkingstoensurethatthemeasurementwillbecarriedoutatthe samepositioneachtime. 6.1.2 Thicknessmeasuringpoints Themarksareplacedonthecentrelineofthetestpiece50mmfromtheendsandatthemidpoint,asshowninFig ure2.Inkmarksonthesurfaceofthetestpieceareconsideredtobeadequate.Othertypesofmarkingsmaybeused ifproventogivecorrectresults. 6.1.3 Lengthmeasuringpoints Asuitablereferencesystemcomprisesglassplateswithathicknessofatleast1mmgluedtotheendsofthetest piece.Analternativereferencesystemismetalknobs,placedatadistanceof250mmapart,approximately25mm fromeachend.Theknobscanbemechanicallyfastenedorgluedontothesurfaceofthetestpiece.Theadhesive shallnotbewaterbasedorhygroscopic.Othertypesofreferencesystemsmaybeusedifproventogivecorrectre sults.EN3182002E 6 Dimensionsinmillimetres Key 1I n k m a r k 2 Glassplate Figure2Exampleofasuitable300mmlongtestpiecewithglassplates 6.2Conditioning Thetwosetsoftestpieceswillbetreatedseparatelyandeachconditionedinthreesteps.Conditionthetestpiecesto constantmassineachofthestepsgiveninTable1.Measurelength,thicknessandmassaccordingto6.3aftersteps 2and3. Table1Conditioningclimatesforthetwosetsoftestpieces StepNo. SetNo.1 SetNo.2 1 20C,30relativehumidity 20C,85relativehumidity 2 20C,65relativehumidity 20C,65relativehumidity 3 20C,85relativehumidity 20C,30relativehumidity Constantmassisconsideredtobereachedwhentheresultsoftwosuccessiveweighingoperations,carriedoutatan intervalof24h,donotdifferbymorethan0,1ofthemassofthetestpiece. Theclimateshallbemeasuredandrecordedatanintervalofnotlessthanonceanhourduringtheconditioningofthe testpieces. 6.3Measurements Aftersteps2and3oftheconditioningperiodsthefollowingparametersshallbemeasuredonthetestpieces thedistancebetweenthelengthmarkings.Beforemeasuringthelength,theequipmentshallbecalibratedby usingthecalibrationbardescribedin4.3.Warpedorbenttestpiecesshallbestraightenedduringthemeas urement; thethicknessofthetestpieces.Themeasurementsshallbecarriedoutatthreepoints,seeFigure2; themassofthetestpieces.EN3182002E 7 Allthemeasurementshavetobeperedintheconditioningatmosphereorwithin5minutesafterthetestpieces havebeentakenoutfromtheclimatechamber. 6.4Drying Afterthetest,thetestpiecesshallbedriedaccordingtoEN322andthenbeweighed. 7 Expressionofresults 7.1 Moisturecontent Foreachtestpiececalculatethemoisturecontentforthethreeclimatesinsteps2and3inaccordancewithEN322 byusingtheresultsfrom6.3and6.4.Whennecessary,therecordedmassesshallbecorrectedtotakeaccountofthe massofthemarkingsused. NOTE ForcementbondedparticleboardsdeterminationofmoisturecontentaccordingtoEN322isnotrelevantandcould givemisleadingresults. 7.2 Changeinlength Foreachtestpiecetherelativechangeinlengthiscalculatedaccordingtoequations1and2,androundedoffto thenearest0,1mm/m. 000 1 65 65 85 85 , 65 l l l l usingset1results 1 000 1 65 65 30 30 , 65 l l l l usingset2results 2 where l 85 isthelengthbetweenmeasurementpointsat20C,85relativehumidity,correctedwhennecessary fortheeffectofthemarkingsused,inmillimetres; l 65 isthelengthbetweenmeasurementpointsat20C,65relativehumidity,correctedwhennecessary fortheeffectofthemarkingsused,inmillimetres; l 30 isthelengthbetweenmeasurementpointsat20C,30relativehumidity,correctedwhennecessary arkingsused,inmillimetres; l 65,85 istherelativechangeoflengthforachangeoftherelativehumidityfrom65to85,inmillimetres permetre; l 65,30 istherelativechangeoflengthforachangeoftherelativehumidityfrom65to30,inmillimetres permetre. 7.3 Changeinthickness Foreachtestpiececalculatethechangeinthicknessforeachofthethreepointsaccordingtoequations3and4. Thefinalresultforthetestpieceisthemeanvalueforallthreemeasuredpointsroundedofftothenearest0,1. 00 1 65 65 85 85 , 65 t t t t usingset1results 3 00 1 65 65 30 30 , 65 t t t t usingset2results 4EN3182002E 8 where t 85 isthethicknessat20C,85relativehumidity,correctedwhennecessaryfortheeffectofthe markingsused,inmillimetres; t 65 isthethicknessat20C,65relativehumidity,correctedwhennecessaryfortheeffectofthe markingsused,inmillimetres; t 30 isthethicknessat20C,30relativehumidity,correctedwhennecessaryfortheeffectofthe markingsused,inmillimetres; t 65,85 istherelativechangeofthethicknessforachangeoftherelativehumidityfrom65to85,in percent; t 65,30 istherelativechangeofthethicknessforachangeoftherelativehumidityfrom65to30,in percent. 7.4 Panelresults Foreachpanelandpaneldirection,calculatethemeanvalueandtherangeoisturecontentandchangesof lengthandthickness. 8 Testreport AccordingtoEN3261.blankBS EN 3182002 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for preparing British Standards. 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