1、BRITISH STANDARD BS EN 13258:2003 Materials and articles in contact with foodstuffs Test methods for crazing resistance of ceramic articles The European Standard EN 13258:2003 has the status of a British Standard ICS 67.250; 97.040.60 BS EN 13258:2003 This British Standard was published under the au
2、thority of the Standards Policy and Strategy Committee on 14 March 2003 BSI 14 March 2003 ISBN 0 580 41408 6 National foreword This British Standard is the official English language version of EN 13258:2003. It supersedes DD ENV 13258:1999 which is withdrawn. The UK participation in its preparation
3、was entrusted to Technical Committee CW/29, Tableware, 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
4、 document may be found in the BSI Catalogue under the section entitled “International Standards Correspondence Index”, or by using the “Search” facility of the BSI Electronic Catalogue or of British Standards Online. This publication does not purport to include all the necessary provisions of a cont
5、ract. Users are responsible for its 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 international/European committee any enquiries on the interpretation, or proposals f
6、or 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 page, pages 2 to 10, an inside back cover and a back cover. The BSI copyri
7、ght date displayed in this document indicates when the document was last issued. Amendments issued since publication Amd. No. Date CommentsEUROPEANSTANDARD NORMEEUROPENNE EUROPISCHENORM EN13258 March2003 ICS67.250;97.040.60 Englishversion MaterialsandarticlesincontactwithfoodstuffsTestmethods forcra
8、zingresistanceofceramicarticles Matriauxetarticlesencontactaveclesdenres alimentairesMthodesdessaidelarsistanceau tressaillagedesarticlesencramique WerkstoffeundGegenstndeinKontaktmitLebensmitteln PrfverfahrenfrdieHaarrissbestndigkeitkeramischer Gegenstnde ThisEuropeanStandardwasapprovedbyCENon21Nov
9、ember2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipulatetheconditionsforgivingthisEurope an Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcernings uchnational standardsmaybeobtainedonapplicationtotheManagementCent
10、reortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,German).Aversioninanyotherlanguagemadebytra nslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusasthe official versions. CENmembersarethenationalstandardsbodi
11、esofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Hungary,Iceland,Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,SlovakRepublic,Spain,Sweden,Switzerland and UnitedKingdom. EUROPEANCOMMITTEEFORSTANDARDIZATION COMITEUROPENDENORMALISATION EUROPISCHESKOMITEEFRNORMUNG M
12、anagementCentre:ruedeStassart,36B1050Brussels 2003CEN Allrightsofexploitationinanyformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.EN13258:2003EEN13258:2003(E) 2 Contents page Foreword3 1 Scope 4 2 Termsanddefinitions. .4 3 Principles4 4 Apparatus .4 5 Samples 5 6 Procedure .5 7 Expr
13、essionofresults . .6 8 Testreport . .7 AnnexA (informative) CalculationofaCrazingResistanceIndexfromdataobtainedbymethodA.8 AnnexB (informative) CalculationofaCrazingResistanceIndexfromdataobtainedbyMethodB .10EN13258:2003(E) 3 Foreword Thisdocument(EN13258:2003)hasbeenpreparedbyTechnicalCommitteeCE
14、N/TC194“Utensilsincontactwith food”,thesecretariatofwhichisheldbyBSI. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationofanidenticaltextor byendorsement,atthelatestbySeptember2003,andconflictingnationalstandardsshallbewithdrawnatthe latestbySeptember2003. Thisdocuments
15、upersedesENV13258:1998. AnnexesAandBareinformative. AccordingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsofthefollowing countriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,CzechRepublic,Denmark,Finland, France,Germany,Greece,Hungary,Iceland,Ireland,Italy,Luxembo
16、urg,Malta,Netherlands,Norway,Portugal, SlovakRepublic,Spain,Sweden,SwitzerlandandtheUnitedKingdom.EN13258:2003(E) 4 1Scope ThisEuropeanStandardspecifiestwotestmethods(methodsAandB)forthedeterminationofcrazingresistance ofglazedceramictablewarearticlesincontactwithfoodwithwaterabsorptionhigherthan0,5
17、%(determined accordingtomethodCofEN1217:1997).MethodAisatestforresistancetocrazingduetomoistureexpansion. MethodBisatestforresistancetocrazingduetothermalshockandissimilarinmostrespectsto EN1183:1997. 2 Termsanddefinitions ForthepurposesofthisEuropeanStandard,thefollowingtermsanddefinitionsapply. 2.
18、1 crazing formationofveryfinecracksintheglazecausedbyeithermoistureexpansionofthebodyorthermalstresswhich createssufficienttensionintheglazetocauseittocraze 2.2 moistureexpansion expansionofceramicbodieswithhighwaterabsorptionduetopenetrationofwatervapourthroughimperfectionsin theglaze 2.3 thermalsh
19、ock suddenchangeintemperature 3Principles 3.1 MethodA Thesamplesaresubjectedtosaturatedsteamatadefinedpressureforanumberofcyclesinanautoclavetotest resistancetocrazingduetomoistureexpansion.Thesteampressureisincreasedandreducedslowlyinorderto minimizethermalshock.Thesamplesareexaminedforcrazingafter
20、eachcycle.Astainisappliedtothesurfaceto aidinthedetectionofcrazingcracks. 3.2 MethodB Samplesareheatedinatestovenandthencooledrapidlyinacoldwaterbathundercontrolledconditionsinorder tosubjectthearticlestothermalshock. Thermalshocktestsarerepeatedusingincreasingtemperaturedifferences.Thesamplesareexa
21、minedforcrazing aftereachthermalshocktest.Thewaterinthecoldwaterbathisstainedtoaidinthedetectionofcrazingcracks. 4Apparatus NOTE Items4.1,4.2and4.3arerequiredformethodAanditems4.4,4.5,4.6,4.7and4.8arerequiredformethodB. 4.1 Autoclaveofsufficientvolumetocontainseveralsamples,builtforasteampressureofa
22、tleast500kPa. Thesteammaybeprovidedbyeitherexternalorinternalheatingoftheautoclaveorfromaseparatesteam generator.Theautoclaveshallbeequippedwith:apressuregauge;asafetyvalve;ameanstoreducepressure withintheautoclavetoatmosphericpressureforsafeopeningattheendofeachcycleandameansofcontrolling thesteamp
23、ressureat(34034)kPa. 4.2 Aqueoussolution containing(51)g/lofeosineand(51)g/lofdomesticwashingupliquid.EN13258:2003(E) 5 4.3 Softcottoncloth 4.4 Coldwaterbath ,comprisingabathortankcapableofcontainingatleastfivetimestheapparentvolumeof theoveralldimensionsofthesamplesbeingtestedatonetime(includingthe
24、basket),fittedwithawatercirculator, athermometerandathermostaticcontrolcapableofmaintaining,forthedurationofallthetests,thewater temperaturetowithin2Cofaspecifiedlowertemperature,t 2 ,withintherange10Cto20C. 4.5 Testoven,preferablyelectricallyheated,havingatemperatureoperatingrangeofuptoatleast300C,
25、 fittedwithanaircirculatingdevicetoensurethatthetemperaturevariationdoesnotexceed5Canda thermostaticcontrolcapableofmaintainingthetemperaturetowithin2Cupto180Candtowithin3C above180C. 4.6 Basket,fortestingtwoormoresamplessimultaneously,madeoutof,orcoatedwith,aninertmaterialwhich willnotdamagethesurf
26、aceofthesamplesduringthetestprocedure.Thebasketiscapableofholdingthesamples inapositionwhichensuresthatairescapesandliquidcanimmediatelyentertheinsideofholloware.Thesamples areheldseparatelytoallowfreepassageofwaterbetweenthem.Thebasketisfittedwithclampstopreventthe samplesfromfloatingwhenimmersed.
27、NOTE Forthemultipletestingofsamples,thebasketmaybecombinedwithanautomaticdeviceforinsertingitinthetest oven( 4.5)andtransferringittothecoldwaterbath( 4.4). 4.7 Tongs, withtipsprotectedbyaheatresistingmaterialsuchasglassormineralwool. 4.8 Gloves,gauntlettype,madefromaheatresistingmaterial. 5Samples T
28、hecompletetestshallbeperformedonnotlessthan7wholeunusedsamples. NOTE Duetoslightlydifferentmanufacturingmethodsitisadvisabletotestbothhollowareandflatware 6Procedure 6.1 MethodA 6.1.1 Removeanydirtorloosedebrisfromthesamples;examinetoverifythattheyarefreefromcrazing. 6.1.2 Placethesamplesonasuitable
29、supportintheautoclave( 4.1)atleast5cmabovethewaterlineatroom temperatureandinsuchawaythatthereisaclearspacebetweenthemandthenclosetheautoclave. 6.1.3 Raisethepressureintheautoclavegraduallyforaperiodofnotlessthan15minandnotmorethan1h untilitreaches340kPaandmaintainat(34034)kPafor2h. 6.1.4 Allowthepr
30、essureintheautoclavetofalltoatmospheric.Allowthesamplestocoolfor1handthenopen theautoclaveandremovethetestsamples. 6.1.5 Immersethesamplesinthestainingagent( 4.2)for(51)min,thenwipeoffthestainwiththecottoncloth (4.3). 6.1.6 Inspecteachsampleimmediatelyforcrazinganddeterminethenumberofsampleswhichhav
31、efailedthe test. 6.2 MethodB 6.2.1 Removeanydirtorloosedebrisfromthesamples;drythemifnecessaryandexaminetoverifythatthey arefreefromcrazing.EN13258:2003(E) 6 6.2.2 Fillthecoldwaterbath( 4.4)withwatercontainingastainingagent,toavolumeequaltonotlessthanfive timestheapparentoverallvolumeofthesamplestob
32、etested(includingthevolumeofthebasket)andtoadepth sufficientforcompleteimmersionofthesamplesplusnotlessthan50mm. NOTE Asuitablestainingagentiseosineintroducedataconcentrationof(51)g/1. Locatethewaterbathneartothetestoven( 4.5)andadjustandmaintainthewatertemperaturetowithin2Cof thespecifiedlowertempe
33、rature,t 2 . 6.2.3 Placethesamples,eitherseparatelyorcontainedinthebasket( 4.6)inthetestovenwhichhasbeen previouslyheatedtotheuppertemperature,t 1 .Maintainthesamplesatthistemperatureuntiltheyhavereached equilibrium. NOTE Thetimetakenforsamplestoreachequilibriumwithtemperaturet 1maybedeterminedbysim
34、pleexperimentation withanequivalentmassofsand.Thesandisplacedinabeakerwithathermometerinsertedintothecentreofthebodyof sandandheatedinthetestoven.Thetimetakentoreachtemperaturet 1isnotedandasafetymarginof5minisadded. 6.2.4 Removethesamplesfromthetestoveneither,oneatatime,holdingthemwiththetongs( 4.7
35、),orifthe samplesarelargeorcontainedinabasketwiththegloves( 4.8).Immersethesamplescompletelyinthecoldwater bathwithoutimpactforaspecifiedperiodbetween8sand2minensuringthathollowareisfilledwithwater. Completetheprocessoftransferringeachsample,orthebasketwithsamples,fromopeningofthetestovento immersio
36、nin(51)s.Ensurethatthedifferenceintemperaturebetweenthetestovenandthecoldwaterbathis notmorethan3Cfromtherequiredtemperatureatthetimeoftransference. 6.2.5 Removethesamplesfromthecoldwater.Inspecteachsampleimmediatelyforcrazinganddeterminethe numberofsamples,whichhavefailedthetest. 6.3 Determinationo
37、fcrazingresistance 6.3.1Method A RepeatthetestingprocedureaccordingtomethodAuntilallsampleshavefailed. NOTE Itisenvisagedthatallsampleswillfailbeforethecompletionofthefifthcycle.Wherethisdoesnothappenitis consideredthattheresultwillnotchangesignificantlywithextendedtesting.Therefore,terminatetheproc
38、edureafterthe seventhcycle. 6.3.2Method B Commencetestingwithatemperaturedifferencevaluet 1 t 2 of(1005)Candincreaset 1 by20Cincrements. RepeatthetestingproceduresaccordingtomethodBwithincreasingtemperaturedifferencevalues,t 1 t 2, untilall sampleshavefailed. NOTE Itisenvisagedthatallsampleswillfail
39、beforeatemperaturedifferencevalue,t 1t 2,of200Cisreached.Where thisdoesnothappenitisconsideredthattheresultwillnotchangesignificantlywithextendedtesting.Therefore,terminate the procedureafteratemperaturedifferencevalue,t 1 t 2,of200Cisreached. 7 Expressionofresults 7.1Crazing 7.1.1Method A Thecyclen
40、umberatwhicheachsamplefailsthecrazingtestisrecordedtogetherwiththecumulativetimeThours (cyclenumber 2foreachsample).Anysamples,whichsurvive7cycles,arealsoreported.EN13258:2003(E) 7 7.1.2Method B Sampleswhichcrazearerecordedashavingfailedthecrazingtestatatemperaturedifferenceoft 1 t 2. Any samples,wh
41、ichsurviveatthemaximumtemperaturedifferenceof200C,arealsoreported. 7.2Crazing resistance 7.2.1Method A Recordthenumberoffailuresaftereach2hcycleandthenumberthatsurvive7cycles. CalculateaCrazingResistanceIndexinaccordancewiththeexamplesgiveninannexA. 7.2.2Method B Recordthenumberoffailuresateachtempe
42、raturedifferenceandthenumberofsamplesthatsurviveatthe maximumtemperaturedifferenceof200C. CalculateaCrazingResistanceIndexinaccordancewiththeexamplesgiveninannexB. 8 Testreport Thetestreportshallincludethefollowingdetails: a) areferencetothisEuropeanStandard; b) anidentificationofthesamplestested; c) thenumberofsamplestakenforthetestandthesamplingmethod; d) forthecrazingtest: thetestmethodused,i.e.AorB; foreachsamplethecumulativetimeformethodAorthetemperaturedifferencet 1 t 2 indegreesCelsius formethodB; the number of samples which failedthetestateachcycleformethodAorateachtemperature increme
