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3、21:1993 which is withdrawn.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
