BS EN 318-2002 Wood based panels - Determination of dimensional changes associated with changes in relative humidity《木质板材 与相对湿度变化有关的尺寸变化的测定》.pdf

1、BRITISH STANDARD BS EN 318:2002 Wood based panels Determination of dimensional changes associated with changes in relative humidity The European Standard EN 318:2002 has the status of a British Standard ICS 79.060.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 318:200

2、2 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

3、British Standard is the official English language version of EN 318:2002. It supersedes BS EN 318:1993 which is withdrawn.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 th

4、is 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”,

5、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

6、 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 informed; monitor related international and European developments and promulgate them in the U

7、K. 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 C

8、ommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN318 March2002 ICS79.060.01 SupersedesEN318:1993 Englishversion WoodbasedpanelsDeterminationofdimensionalchanges associatedwithchangesinrelativehumidity PanneauxbasedeboisDterminationdesvariations dimensionnellessouslinfluencedevariationsdelhumi

9、dit relative HolzwerkstoffeBestimmungvonManderungenin VerbindungmitnderungenderrelativenLuftfeuchte ThisEuropeanStandardwasapprovedbyCENon24February2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstand

10、ardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibil

11、ityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Sweden,Swit

12、zerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2002CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN318:2002EEN318:2002(E) 2 Contents

13、 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

14、 .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 . .8EN318:2002(E) 3 Foreword Thisdocu

15、ment(EN318:2002)hasbeenpreparedbyTechnicalCommitteeCEN/TC112“Woodbasedpanels“,the secretariatofwhichisheldbyDIN. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbySeptember2002,andconflictingnationalstandardsshallbewithdraw

16、natthelat estbySeptember2002. ThisdocumentsupersedesEN318:1993. ComparedtotheversionEN318:1993thefollowingmodificationshavebeenmade: a) Thescopehasbeenextendedfromfibreboardstowoodbasedpanels b) Theconditioningprocedurehasbeenmodified AccordingtotheCEN/CENELECInternalRegulations,thenationalstandards

17、organizationsofthefollowingcoun triesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,Spain,Swe den,SwitzerlandandtheUnitedKingdom.EN318:2002(E) 4 1Scope ThisEuropeanStandar

18、dspecifiesamethodforthedeterminationofdimensionalchangesinwoodbasedpanels, duetochangesintherelativehumidityoftheair. 2 Normativereferences ThisEuropeanStandardincorporatesbydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriateplacesinthetext,andth

19、epublicationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferencesthelatesteditionofthe publicationreferredtoapplies(includingamendments). EN322, WoodbasedpanelsDe

20、terminationofmoisturecontent. EN3261, WoodbasedpanelsSampling,cuttingandinspectionPart1:Samplingandcuttingoftestpieces andexpressionoftestresults. 3Principle Becausevariationsinrelativehumidityaffectthemoisturecontentofapanelandresultinchangestoitsdimen sions,testpiecesaremeasuredafterconditioningto

21、differentlevelsofrelativehumidity. Theequilibriummoisturecontentofpanelproductsisdependentonthehistoryofmoisturechange.Higherequilibrium moisturecontentsforanyonerelativehumidityareachievedindesorptioncomparedwithadsorption;thisgivesriseto ahysteresiseffect. Inordertoobtainthetruedimensionalchange,t

22、hisismeasuredbetween65%relativehumidityand85%relative humidityinadsorptionand65%relativehumidityand30%relativehumidityindesorption. 4Apparatus 4.1Balance BalanceasdescribedinEN322. 4.2 Measuringinstrumentsforlengthandthickness Instrumentsformeasuringlengthandthicknesswithanaccuracyof0,01mm.Anexample

23、ofalengthmeasuring equipmentisshowninFigure1. 4.3 Calibrationbar Corrosionresistantmetalbarofsufficientlengthandshapetocalibratethelengthmeasuringequipment.Thelength ofthecalibrationbarshallbeknowntowithin0,01mm. 4.4 Climatechamber Climatechamber(s)capableofmaintainingtherequiredtemperatureto1Candre

24、lativehumidityto3%.EN318:2002(E) 5 Figure1Exampleoflengthmeasuringequipment 4.5 Dryingcabinet Ventilateddryingoven,capableofbeingcontrolledat(1032)C. 4.6Hygrometer Hygrometerwithanaccuracyof1%relativehumiditytomeasureandrecordtherelativeairhumidityintheclimate chamber. 4.7Thermometer Thermometerwith

25、anaccuracyof0,5Ctomeasureandrecordtemperatureintheclimatechamber. 5 Testpieces Thenormaldimensionsoftestpiecesare(3002)mm (502)mm t(panelthickness)butlongertestpiecesmay beused.Fromeachpanel,twosetsoffourtestpiecesshallbecutineachpaneldirectiontogive16testpiecesper panelintotal.Thegeneralconditionsf

26、orsamplingofthetestpiecesshallbeinaccordancewithEN3261. 6Procedure 6.1 Testpiecepreparation 6.1.1General Thetestpiecesshallbepreparedwithsuitablemarkingstoensurethatthemeasurementwillbecarriedoutatthe samepositioneachtime. 6.1.2 Thicknessmeasuringpoints Themarksareplacedonthecentrelineofthetestpiece

27、50mmfromtheendsandatthemidpoint,asshowninFig ure2.Inkmarksonthesurfaceofthetestpieceareconsideredtobeadequate.Othertypesofmarkingsmaybeused ifproventogivecorrectresults. 6.1.3 Lengthmeasuringpoints Asuitablereferencesystemcomprisesglassplateswithathicknessofatleast1mmgluedtotheendsofthetest piece.An

28、alternativereferencesystemismetalknobs,placedatadistanceof250mmapart,approximately25mm fromeachend.Theknobscanbemechanicallyfastenedorgluedontothesurfaceofthetestpiece.Theadhesive shallnotbewaterbasedorhygroscopic.Othertypesofreferencesystemsmaybeusedifproventogivecorrectre sults.EN318:2002(E) 6 Dim

29、ensionsinmillimetres Key 1I n k m a r k 2 Glassplate Figure2Exampleofasuitable300mmlongtestpiecewithglassplates 6.2Conditioning Thetwosetsoftestpieceswillbetreatedseparatelyandeachconditionedinthreesteps.Conditionthetestpiecesto constantmassineachofthestepsgiveninTable1.Measurelength,thicknessandmas

30、saccordingto6.3aftersteps 2and3. Table1Conditioningclimatesforthetwosetsoftestpieces Step(No.) SetNo.1 SetNo.2 1 20C,30%relativehumidity 20C,85%relativehumidity 2 20C,65%relativehumidity 20C,65%relativehumidity 3 20C,85%relativehumidity 20C,30%relativehumidity Constantmassisconsideredtobereachedwhen

31、theresultsoftwosuccessiveweighingoperations,carriedoutatan intervalof24h,donotdifferbymorethan0,1%ofthemassofthetestpiece. Theclimateshallbemeasuredandrecordedatanintervalofnotlessthanonceanhourduringtheconditioningofthe testpieces. 6.3Measurements Aftersteps2and3oftheconditioningperiodsthefollowing

32、parametersshallbemeasuredonthetestpieces: thedistancebetweenthelengthmarkings.Beforemeasuringthelength,theequipmentshallbecalibratedby usingthecalibrationbardescribedin4.3.Warpedorbenttestpiecesshallbestraightenedduringthemeas urement; thethicknessofthetestpieces.Themeasurementsshallbecarriedoutatth

33、reepoints,seeFigure2; themassofthetestpieces.EN318:2002(E) 7 Allthemeasurementshavetobeperformedintheconditioningatmosphereorwithin5minutesafterthetestpieces havebeentakenoutfromtheclimatechamber. 6.4Drying Afterthetest,thetestpiecesshallbedriedaccordingtoEN322andthenbeweighed. 7 Expressionofresults

34、 7.1 Moisturecontent Foreachtestpiececalculatethemoisturecontentforthethreeclimatesinsteps2and3inaccordancewithEN322 byusingtheresultsfrom6.3and6.4.Whennecessary,therecordedmassesshallbecorrectedtotakeaccountofthe massofthemarkingsused. NOTE Forcementbondedparticleboardsdeterminationofmoistureconten

35、taccordingtoEN322isnotrelevantandcould givemisleadingresults. 7.2 Changeinlength Foreachtestpiecetherelativechangeinlengthiscalculatedaccordingtoequations(1)and(2),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 (usingset2result

36、s) (2) where l 85 isthelengthbetweenmeasurementpointsat20C,85%relativehumidity,correctedwhennecessary fortheeffectofthemarkingsused,inmillimetres; l 65 isthelengthbetweenmeasurementpointsat20C,65%relativehumidity,correctedwhennecessary fortheeffectofthemarkingsused,inmillimetres; l 30 isthelengthbet

37、weenmeasurementpointsat20C,30%relativehumidity,correctedwhennecessary formarkingsused,inmillimetres; l 65,85 istherelativechangeoflengthforachangeoftherelativehumidityfrom65%to85%,inmillimetres permetre; l 65,30 istherelativechangeoflengthforachangeoftherelativehumidityfrom65%to30%,inmillimetres per

38、metre. 7.3 Changeinthickness Foreachtestpiececalculatethechangeinthicknessforeachofthethreepointsaccordingtoequations(3)and(4). Thefinalresultforthetestpieceisthemeanvalueforallthreemeasuredpointsroundedofftothenearest0,1%. 00 1 65 65 85 85 , 65 t t t t (usingset1results) (3) 00 1 65 65 30 30 , 65 t

39、 t t t (usingset2results) (4)EN318:2002(E) 8 where t 85 isthethicknessat20C,85%relativehumidity,correctedwhennecessaryfortheeffectofthe markingsused,inmillimetres; t 65 isthethicknessat20C,65%relativehumidity,correctedwhennecessaryfortheeffectofthe markingsused,inmillimetres; t 30 isthethicknessat20

40、C,30%relativehumidity,correctedwhennecessaryfortheeffectofthe markingsused,inmillimetres; t 65,85 istherelativechangeofthethicknessforachangeoftherelativehumidityfrom65%to85%,in percent; t 65,30 istherelativechangeofthethicknessforachangeoftherelativehumidityfrom65%to30%,in percent. 7.4 Panelresults

41、 Foreachpanelandpaneldirection,calculatethemeanvalueandtherangeformoisturecontentandchangesof lengthandthickness. 8 Testreport AccordingtoEN3261.blankBS EN 318:2002 BSI 389 Chiswick High Road London W4 4AL BSI British Standards Institution BSI is the independent national body responsible for prepari

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