BS EN 321-2002 Wood-based panels - Determination of moisture resistance under cyclic test conditions《木基板材 循环试验条件下抗湿性的测定》.pdf

1、BRITISH STANDARD BS EN 321:2002 The European Standard EN 321:2001 has the status of a British Standard ICS 79.060 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAWBS EN 321:2002 This British Standard, having been prepared under the direction of the Sector Policy and Strategy Com

2、mittee for Building and Civil Engineering, was published under the authority of the Standards Policy and Strategy Committee on 28 January 2002 BSI 28 January 2002 ISBN 0 580 38913 8 National foreword This British Standard is the official English language version of EN 321:2001. It supersedes BS EN 3

3、21:1993 which is withdrawn.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 this committee can be obtained on request to its secretary. Cross-references The British Standard

4、s 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 d

5、oes 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 responsi

6、ble 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 UK. Summary of pages This document comprises a front cover, an inside front cover, the EN title

7、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 EN321 November2001 ICS79.060.01 Supersede

8、sEN321:1993 Englishversion WoodbasedpanelsDeterminationofmoistureresistance undercyclictestconditions PanneauxbasedeboisDterminationdelarsistance lhumiditselonessaiscycliques HolzwerkstoffeBestimmungderFeuchtebestndigkeit durchZyklustest ThisEuropeanStandardwasapprovedbyCENon30September2001. CENmemb

9、ersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember

10、. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodiesofAustria,Belgiu

11、m,CzechRepublic,Denmark,Finland,France,Germany,Greece, Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden,SwitzerlandandUnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 200

12、1CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN321:2001EEN321:2001(E) Contents page Foreword. 3 1 Scope. 4 2 N o r m a t i v e r e f e r e n c e s 4 3Principle. 4 4 Apparatus 4 5 T e s t p i e c e s . 5 6 P roc edure 5 7 E x p r e s s i o n o f r

13、e s u l t s 7 8 Testreport . 7 Bibliography 8 2EN321:2001(E) Foreword ThisEuropeanStandardhasbeenpreparedbyTechnicalCommitteeCEN/TC112“Woodbasedpanels“,the secretariatofwhichisheldbyDIN. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement

14、,atthelatestbyMay2002,andconflictingnationalstandardsshallbewithdrawnatthelatestby May2002. ThisEuropeanStandardsupersedesEN321:1993. Thisstandardisoneofaseriesspecifyingmethodsoftestfordeterminingthebehaviourofwoodbasedpanels undertheinfluenceofmoisture. ThisstandardisarevisedversionofEN321:1993and

15、AC:1994.ComparedtotheversionEN321:1993and AC:1994thefollowingmodificationshavebeenmade: a)Thescopehasbeenextendedfromfibreboardstowoodbasedpanels. b)Themethodhasbeendescribedinmoredetailinordertoavoidmisinterpretationandimprovereproducibility. AccordingtotheCEN/CENELECInternalRegulations,thenational

16、standardsorganizationsof thefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Iceland,Ireland,Italy,Luxembourg,Netherlands,Norway,Portugal,Spain,Sweden, SwitzerlandandtheUnitedKingdom. 3EN321:2001(E) 1Scope ThisEuropeanSta

17、ndardspecifiesatestmethodforthedeterminationofthemoistureresistanceofwoodbased panelsundercyclictestconditions. 2Normativereferences ThisEuropeanStandardincorporates,bydatedorundatedreference,provisionsfromotherpublications.These normativereferencesarecitedattheappropriateplacesinthetext,andthepubli

18、cationsarelistedhereafter.For datedreferences,subsequentamendmentstoorrevisionsofanyofthesepublicationsapplytothisEuropean Standardonlywhenincorporatedinitbyamendmentorrevision.Forundatedreferences,thelatesteditionofthe publicationreferredtoapplies(includingamendments). EN310, WoodbasedpanelsDetermi

19、nationofmodulusofelasticityinbendingandofbendingstrength. EN317, ParticleboardsandfibreboardsDeterminationofswellinginthicknessafterimmersioninwater. EN319, ParticleboardsandfibreboardsDeterminationoftensilestrengthperpendiculartotheplaneoftheboard. EN325, WoodbasedpanelsDeterminationofdimensionsoft

20、estpieces. EN3261, WoodbasedpanelsSampling,cuttingandinspectionPart1:Samplingandcuttingoftestpieces andexpressionoftestresults. 3Principle Testpiecesareexposedtothreecycles,eachcomprisingimmersioninwater,freezing,anddryingatelevated temperature.Aftercyclictreatment,thetestpiecesarethenreconditioneda

21、ndtheirswellinginthicknessand residualstrengthdetermined. 4Apparatus 4.1Waterbath Awaterbathwhichshallmaintainwateratatemperatureof(201)C. 4.2Freezingcabinet Afreezingcabinetwhichshallbecapableofmaintainingatemperatureofbetween12Cand25C.Itshallalso becapableofregainingthistemperaturewithin1hafterins

22、ertingthetestpieces. 4.3Dryingcabinet Alaboratorydryingcabinetwithforced,evenlydistributedairventilation,whichshallmaintainatemperatureof (702)Candhave(255)airexchangesperhour.Itshallbecapableofreachingatemperatureof(702)C within2hafterinsertingthetestpieces. 4EN321:2001(E) 5Testpieces 5.1Sampling S

23、amplingandcuttingofthetestpiecesshallbecarriedoutaccordingtoEN3261andtherelevantmaterial specificationstandard. 5.2 Dimensionsoftestpieces DimensionsshallbeinaccordancewithEN310,EN317andEN319asappropriate. 5.3Conditioning Thetestpiecesshallbeconditionedtoconstantmassinanatmospherewitharelativehumidi

24、tyof(655)%and atemperatureof(202)C.Constantmassisconsideredtobereachedwhentheresultsoftwosuccessive weighingoperations,carriedoutatanintervalof24h,donotdifferbymorethan0,1%ofthemassofeachtest piece. 6Procedure 6.1 Treatmentofthetestpieces Thefollowingsequenceofoperationsshallbecarriedout: 6.1.1Initi

25、alconditioningandmeasurement 1)Conditionthetestpiecesinaccordancewith5.3. 2)DeterminethedimensionsofthetestpiecesinaccordancewithEN325. 6.1.2Cyclictreatment 6.1.2.1Firstcycle 3)ImmersethetestpiecesinthewaterbathwhichshallcontainfreshwaterofpH=(71)andbeatatempera tureof(201)C. Thetestpiecesshallbepla

26、cedstandingononeedge(onelongedgeinthecaseofthebendingtestpieces)and shallbeseparatedfromeachother,andfromthebottomandsidesofthewaterbathbyatleast15mm.The upperedgesoftestpiecesshallbecoveredby(255)mmofwaterthroughouttheimmersionperiod. Theimmersionperiodshallbe(701)h. 4)Removethetestpiecesfromthewat

27、erbath.Allowthesurfacewatertodrainoffforafewminutesandthen placethetestpiecesinthefreezingcabinetwhichshallbeatatemperaturebetween12Cand25C. Thetestpiecesshallbeplacedstandingonthesameedgeaswhenimmersed,andshallbeseparatedfrom eachotherbyatleast15mm. Thefreezingperiodshallbe(241)h. 5)Removethetestpi

28、ecesfromthefreezingcabinetandimmediatelyplacetheminthedryingcabinetwhichshall beatatemperatureof(702)C. Thetestpiecesshallbeplacedstandingonthesameedgesaswhenimmersedandfrozen,andshallbe separatedfromeachotherbyatleast15mm.Thetotalvolumeofthetestpiecesshallnotexceed10%ofthe internalvolumeofthedrying

29、cabinet. 5EN321:2001(E) Thedryingperiodshallbe(701)h. 6)Removethetestpiecesfromthedryingcabinetandplacetheminaroomatatemperatureof(205)C. Thetestpieceshallbeplacedstandingonthesameedgeaswhenimmersed,frozenanddried,andshallbe separatedfromeachotherbyatleast15mm. Thecoolingperiodshallbe(40,5)h. 6.1.2.

30、2Secondcycle 7)Attheendofthecoolingperiodimmersethetestpiecesagaininthewaterbathwhichshallcontainfresh waterofpH=(71)andbeatatemperatureof(201)C. Beforestandingtheminthewaterbath,thetestpiecesshallbeinvertedtostandonitsoppositeedge.Thetest piecesshallbeseparatedfromeachotherandfromthebottomandsideso

31、fthebathbyatleast15mm.The upperedgesoftestpiecesshallbecoveredby(255)mmofwaterthroughouttheimmersionperiod. Theimmersionperiodshallbe(701)h. 8)Removethetestpiecesfromthewaterbath.Allowthesurfacewatertodrainoffforafewminutesandthen placethetestpiecesinthefreezingcabinetwhichshallbeatatemperaturebetwe

32、en12Cand25C. Thetestpiecesshallbeplacedstandingonthesameedgesaswhenimmersed(7),andshallbeseparatedfrom eachotherbyatleast15mm. Thefreezingperiodshallbe(241)h. 9)Removethetestpiecesfromthefreezingcabinetandimmediatelyplacetheminthedryingcabinetwhichshall beatatemperatureof(702)C. Thetestpiecesshallbe

33、placedstandingonthesameedgeaswhenimmersed(7)andfrozen(8),andshallbe separatedfromeachotherbyatleast15mm.Thetotalvolumeofthetestpiecesshallnotexceed10%ofthe internalvolumeofthedryingcabinet. Thedryingperiodshallbe(701)h. 10)Removethetestpiecesfromthedryingcabinetandplacetheminaroomwithatemperatureof(

34、205)C. Thetestpieceshallbeplacedonthesameedgeaswhenimmersed(7),frozen(8)anddried(9),andshallbe separatedfromeachotherbyatleast15mm. Thecoolingperiodshallbefor(40,5)h. 6.1.2.3Thirdcycle 11)Attheendofthecoolingperiodimmersethetestpiecesagaininthewaterbathwhichshallcontainfresh waterofpH=(71)andbeatate

35、mperatureof(201)C. Beforestandingtheminthewaterbath,thetestpiecesshallbeinvertedtostandonitsoppositeedge(i.e.each testpieceshallbestandingonthesameedgeasduringtheinitialimmersionperioddescribedin3).Thetest piecesshallbeseparatedfromeachotherandfromthebottomandsidesofthebathbyatleast15mm.The upperedg

36、esoftestpiecesshallbecoveredby(255)mmofwaterthroughouttheimmersionperiod. Theimmersionperiodshallbe(701)h. 12)Removethetestpiecesfromthewaterbath.Allowthesurfacewatertodrainoffforafewminutesandthen placethetestpiecesinthefreezingcabinetwhichshallbeatatemperaturebetween12Cand25C. 6EN321:2001(E) Thete

37、stpiecesshallbeplacedstandingonthesameedgeaswhenimmersed(11),andshallbeseparatedfrom eachotherbyatleast15mm. Thefreezingperiodshallbe(241)h. 13)Removethetestpiecesfromthefreezingcabinetandimmediatelyplacetheminthedryingcabinetwhich shallbeatatemperatureof(702)C. Thetestpiecesshallbeplacedstandingont

38、hesameedgeaswhenimmersed(11)andfrozen(12),andshall beseparatedfromeachotherbyatleast15mm.Thetotalvolumeofthetestpiecesshallnotexceed10%of theinternalvolumeofthedryingcabinet. Thedryingperiodshallbe(701)h. NOTEStages3to13abovetakeapproximately500htocomplete. 6.1.3Reconditioning 14)Removethetestpiecef

39、romthedryingcabinetandconditionthemtoconstantmass. 15)DeterminethedimensionsofthetestpiecesinaccordancewithEN325. 6.2Determinationofswellinginthickness DeterminetheswellinginthicknessofthetestpiecesaftercyclictestaccordingtoEN317. 6.3Determinationoftensilestrengthperpendiculartotheplaneoftheboard De

40、terminethetensilestrengthperpendiculartotheplaneoftheboardaccordingtoEN319usingthedimensions determinedin6.1.1. NOTEBeforebondingthetestpiecestotheloadingblocks,theirfacesmaybelightlysandedtoremoveanyroughnesscaused bythecyclictest. 6.4Determinationofbendingstrength Whenrequired,determinethebendings

41、trengthaccordingtoEN310usingthedimensionsofthetestpiecesafter eitherinitial(6.1.1)orfinal(6.1.3)conditioningdependingontherequirementsoftherelevantspecification. 7Expressionofresults 7.1 Swellinginthickness AccordingtoEN317. 7.2Tensilestrength AccordingtoEN319. 7.3Bendingstrength AccordingtoEN310.Th

42、emethodofcalculationusedshallbestatedinthereport. 8 Testreport AccordingtoEN3261. 7EN321:2001(E) Bibliography EN300, OrientedStrandBoards(OSB)Definitions,classificationandspecifications. EN3125, ParticleboardsSpecificationsPart5:Requirementsforloadbearingboardsforuseinhumid conditions. EN3127, ParticleboardsSpecificationsPart7:Requirementsforheavydutyloadbearingboardsforusein humidconditions. EN6225, FibreboardsSpecificationsPart5:Requirementsfordryprocessboards(MDF). EN6342, CementbondedparticleboardsSpecificationsPart2:Requiremen