欢迎来到麦多课文档分享! | 帮助中心 海量文档,免费浏览,给你所需,享你所想!
麦多课文档分享
全部分类
  • 标准规范>
  • 教学课件>
  • 考试资料>
  • 办公文档>
  • 学术论文>
  • 行业资料>
  • 易语言源码>
  • ImageVerifierCode 换一换
    首页 麦多课文档分享 > 资源分类 > PDF文档下载
    分享到微信 分享到微博 分享到QQ空间

    BS ISO 974-2000 Plastics - Determination of the brittleness temperature by impact《塑料 用冲击法测定脆性温度》.pdf

    • 资源ID:588212       资源大小:260.59KB        全文页数:16页
    • 资源格式: PDF        下载积分:10000积分
    快捷下载 游客一键下载
    账号登录下载
    微信登录下载
    二维码
    微信扫一扫登录
    下载资源需要10000积分(如需开发票,请勿充值!)
    邮箱/手机:
    温馨提示:
    如需开发票,请勿充值!快捷下载时,用户名和密码都是您填写的邮箱或者手机号,方便查询和重复下载(系统自动生成)。
    如需开发票,请勿充值!如填写123,账号就是123,密码也是123。
    支付方式: 支付宝扫码支付    微信扫码支付   
    验证码:   换一换

    加入VIP,交流精品资源
     
    账号:
    密码:
    验证码:   换一换
      忘记密码?
        
    友情提示
    2、PDF文件下载后,可能会被浏览器默认打开,此种情况可以点击浏览器菜单,保存网页到桌面,就可以正常下载了。
    3、本站不支持迅雷下载,请使用电脑自带的IE浏览器,或者360浏览器、谷歌浏览器下载即可。
    4、本站资源下载后的文档和图纸-无水印,预览文档经过压缩,下载后原文更清晰。
    5、试题试卷类文档,如果标题没有明确说明有答案则都视为没有答案,请知晓。

    BS ISO 974-2000 Plastics - Determination of the brittleness temperature by impact《塑料 用冲击法测定脆性温度》.pdf

    1、| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | BRITISH STANDARD BS ISO 974:2000 ICS 83.08

    2、0.01 NO COPYING WITHOUT BSI PERMISSION EXCEPT AS PERMITTED BY COPYRIGHT LAW Plastics Determination of the brittleness temperature by impactThis British Standard, having been prepared under the direction of the Sector Committee for Materials and Chemicals, was published under the authority of the Sta

    3、ndards Committee and comes into effect on 15 May 2000 BSI 05-2000 ISBN 0 580 34260 3 BS ISO 974:2000 Amendments issued since publication Amd. No. Date Comments National foreword This British Standard reproduces verbatim ISO 974:2000 and implements it as the UK national standard. The UK participation

    4、 in its preparation was entrusted to Technical Committee PRI/21, Testing of plastics, which has the responsibility to: aid enquirers to understand the text; present to the responsible international/European committee any enquiries on the interpretation, or proposals for change, and keep the UK inter

    5、ests informed; monitor related international and European developments and promulgate them in the UK. 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 refer

    6、red 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 c

    7、ontract. Users of British Standards are responsible for their correct application. Compliance with a British Standard does not of itself confer immunity from legal obligations. Summary of pages This document comprises a front cover, an inside front cover, the ISO title page, pages ii to v, a blank p

    8、age, pages 1 to 7 and a back cover. The BSI copyright notice displayed in this document indicates when the document was last issued.Referencenumber ISO974:2000(E) INTERNATIONAL STANDARD ISO 974 Secondedition 2000-01-15 PlasticsDeterminationofthebrittleness temperaturebyimpact Plastiques Dtermination

    9、 de la temprature de fragilit au chocISO974:2000(E) ii ISO974:2000(E)iii Contents 1 Scope1 2 Normativereferences1 3 Termsanddefinitions.1 4 Principle2 5 Apparatus.2 6 Testspecimens3 7 Conditioning.5 8 Procedure.5 9 Expressionofresults6 9.1 Graphicalmethod6 9.2 Calculationmethod.6 10 Testreport7ISO97

    10、4:2000(E) iv Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO memberbodies).TheworkofpreparingInternationalStandardsisnormallycarriedoutthroughISOtechnical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenes

    11、tablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnon-governmental,in liaisonwithISO,alsotakepartinthework.ISOcollaboratescloselywiththeInternationalElectrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredra

    12、ftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtothememberbodiesforvoting. PublicationasanInternationalStandardrequiresapprovalbyatleast75%ofthememberbodiescastingavote. Attentionisdrawntothepossibilitythatsomeoft

    13、heelementsofthisInternationalStandardmaybethesubjectof patentrights.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights. InternationalStandardISO974waspreparedbyTechnicalCommitteeISO/TC61, Plastics, Subcommittee SC 2, Mechanical properties. Thissecondeditioncancelsandreplacesthefirste

    14、dition(ISO974:1980),whichhasbeentechnicallyrevised.ISO974:2000(E)v Introduction Plasticsareusedinmanyapplicationsrequiringlow-temperatureflexingwithorwithoutimpact.Polymerbrittleness isaffectedbyanyorientationproducedduringfabrication,bythermalhistoryandbytheapplicationofstresstothe material,especia

    15、llytherateofappliedstressasinimpact.Brittlenesstemperaturedatamaybeusedtopredictthe behaviourofplasticmaterialsatlowtemperatureonlyinapplicationsinwhichtheconditionsofdeformationare similar.Thebrittlenesstemperaturetestwasoriginallydevelopedtomeasurethetemperatureatwhichapolymer ceasestobeflexiblean

    16、dbecomes“glasslike”.INTERNATIONALSTANDARD ISO974:2000(E)1 PlasticsDeterminationofthebrittlenesstemperaturebyimpact 1 Scope ThisInternationalStandardspecifiesamethodforthedeterminationofthetemperatureatwhichplasticsthatare notrigidatnormalambienttemperatureexhibitbrittlefailureunderspecifiedimpactcon

    17、ditions.Asupplementary techniqueusingnotchedspecimensdevelopsbrittlenessvaluesatamuchhighertemperaturethanareobserved forunnotchedspecimensofthesameplasticmaterial.Themethodutilizesastatisticaltechniquetoquantifythe brittlenessfailuretemperature.Provisionsaremadeforthetestingofsufficientspecimenstop

    18、ermitthecalculation ofthebrittlenesstemperatureonastatisticalbasis.Statisticaltechniqueshavebeendevelopedtoquantifythe brittlenesstemperatureasisdefinedin3.1. Themethodestablishesthetemperatureatwhichthereisa50%chanceoffailureineitherunnotchedornotched specimens.Thismethodhasbeenfoundusefulforspecif

    19、icationpurposes,althoughitdoesnotnecessarily measurethelowesttemperatureatwhichthematerialmaybeused.Inthemeasurementofthebrittleness temperature,theprecisionofthemeasurementshouldpreferablybe 5Cattheworstwhenestablishingvalues usedinmaterialspecifications. 2 Normativereferences Thefollowingnormative

    20、documentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsof thisInternationalStandard.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyofthese publicationsdonotapply.However,partiestoagreementsbasedonthisInternationalStandardareencouragedto investigatethepossibilityof

    21、applyingthemostrecenteditionsofthenormativedocumentsindicatedbelow.For undatedreferences,thelatesteditionofthenormativedocumentreferredtoapplies.MembersofISOandIEC maintainregistersofcurrentlyvalidInternationalStandards. ISO175:1999, Plastics Methods of test for the determination of the effects of i

    22、mmersion in liquid chemicals. ISO291:1997, Plastics Standard atmospheres for conditioning and testing. 3 Termsanddefinitions ForthepurposesofthisInternationalStandard,thefollowingtermsanddefinitionsapply: 3.1 brittlenesstemperature thetemperatureatwhichthereisa50%probabilityoffailureinaspecimenwhent

    23、estedbythemethodspecified ItmaybedesignatedT 50 . 3.2 testspeed therelativevelocitybetweenthestrikingedgeofthetestapparatusandatestspecimenheldinthespecimen clampISO974:2000(E) 2 4Principle Testspecimens,supportedascantileverbeams,areimmersedinaheat-transfermediumwhosetemperatureis accuratelyknownan

    24、dpreciselycontrolled.Thespecimensareconditionedforaspecifiedperiodoftimeandthen impactedbyasingleswingofthestrikingedgeoftheapparatusataspecifiedconstantspeed.Asufficientnumber ofspecimensaretestedtopermitthecalculationofthebrittlenesstemperatureonastatisticalbasis.The temperatureatwhich50%ofthespec

    25、imensfailisdefinedasthebrittlenesstemperature. 5 Apparatus 5.1 Testmachine,consistingofaclampingdevicetoholdthetestspecimens,astrikingedgeandamechanical arrangementappropriatetoensurethatthesearemaintainedinproperrelationtoeachotherandthatthestriking edgemovesataconstantspeedrelativetothetestspecime

    26、ns. NOTE1 DetailsofthestrikingedgeandclampingdeviceareshowninFigures1and2,andaphotographoftheclampwith mountedspecimensisshowninFigure3. Theprincipaldimensionsoftheapparatusshallbeasfollows: a) radiusofstrikingedge:1,6mm 0,1mm; b) radiusoflowerjawofclampingdevice:4,0mm 0,1mm; c) distancebetweenpoint

    27、ofimpactofstrikingedgeandclampingdevice:3,6mm 0,1mm; d) clearancebetweenoutsideofstrikingedgeandclampingdevice:2,0mm 0,1mm; Thetestspeedshallbe200cm/s 20cm/satimpactandduringatleastthenext0,5cmoftravel. NOTE2 Commercialapparatusisavailablemeetingtherequirementsofthissubclause,inwhichthestrikingedgei

    28、sdriven byamotor,byasolenoid,bygravityorbyaspring. 5.2 Temperature-measuringsystem:Anysuitabledevicemaybeused.Itshallbecalibratedovertherequired rangeandaccuratetowithin 0,5C.Thetemperature-measuringdeviceshallbeplacedasneartothespecimen aspossible. 5.3 Liquidorgaseousheat-transfermedium,preferablyl

    29、iquid,whichremainsfluidatthetesttemperatureand whichdoesnotappreciablyaffectthematerialbeingtested.Themediumshallbemaintainedatthetest temperaturetowithin 0,5C. NOTE Giventhatthetimeofcontactbetweentheliquidandtheplasticspecimensisshortandthetemperaturelow,the useofamethanol/solid-CO 2 mixturehasbee

    30、nfoundsuitableformostplastics.Thismixturecanbeusedsuccessfullydownto 76C.Belowthistemperature,otherheat-transfermediaareneeded,forexamplesiliconeoils,dichlorodifluoromethane/liquid nitrogen,oranairbath. Shouldanydoubtexistregardingtheinertnessoftheplasticstothemixtureused,measureselectedphysical pro

    31、pertiesbeforeandafter15minexposureatthehighesttemperatureused(seeISO175).Thevaluesobtained shouldnotdiffersignificantly. 5.4 Tank,insulated. 5.5 Stirrer,toprovidethoroughcirculationoftheheat-transfermedium.ISO974:2000(E)3 Dimensionsinmillimetres Key 1 Strikingedge 2 Clampingdevice 3 Testspecimen Fig

    32、ure1Dimensionaldetailsofstrikingedgeandclampingdevice (positioningofunnotchedtestspecimen) 6 Testspecimens 6.1 Formanypolymers,theresultsofthistestdependtoalargedegreeontheconditionsusedforsample preparationandonthemethodofspecimenpreparation.Unlessotherwisespecified,therelevantISOmaterial specifica

    33、tionshallbeusedforthepreparationofthetestsamplefromwhichthespecimensarecut.Cleaneredge cutsandthereductionoreliminationofaccidentalnotcheswillresultinlowerobservedbrittlenesstemperatures. Itisessentialthatthespecimensbepreparedinareproducibleway.Arazorbladeorothersharptoolshallbeused tocutthespecime

    34、ns,preferablyinasinglesmoothstroke.Die-cutspecimensarenotrecommended.Althoughitis possibletopreparesatisfactoryspecimensbyhand,itisstronglyrecommendedthatanautomaticmethodbeused. Whatevermethodisused,itisessentialthatthecutterbeinspectedfrequentlyandmaintained.Sharpcuttersmust beusedinthepreparation

    35、ofspecimensforthistestifreliableresultsaretobeobtained. Theconditionofthediemaybejudgedbyinvestigatingtherupturepointonanyseriesofbrokenspecimens.When brokenspecimensareremovedfromtheclampsofthetestmachine,itisconvenienttomakeapileofthese specimensandnoteifthereisanytendencytobreakatornearthesamepoi

    36、ntoneachspecimen.Rupturepoints consistentlyatthesameplacemaybeanindicationthatthedieisdull,nickedorbentatthatparticularposition. NOTE Fortheuseofanautomaticcutterforspecimenpreparation,seeBestelink,P.N.,andTurner,S.: Low-temperature brittleness testing of polyethylene, ASTM Bulletin No. 231, 68 (195

    37、8). 6.2 Testspecimens20,00mm 0,25mmlongby2,50mm 0,05mmwideand2,0mm 0,1mmthick(see Figure4)shallbecutfromatestsheet.Specimenscanbeconvenientlycuttothespecifieddimensionsfromastrip ofmaterial20,00mm 0,25mminwidthandoftherequiredthickness.Thisispreferablyaccomplishedusingan automaticmachine(seenoteto6.

    38、1).ISO974:2000(E) 4 Dimensionsinmillimetres Key a Twoholes, 3,7mm, countersunk 6,4mm 90 b Removesharpcornersonserrations c Twoinsertedbushes d Twoholes,48A e Twoholes, 3,7mm Figure2Detailsofoneformofclampmeetingtherequirementsof5.1ISO974:2000(E)5 Figure3Assembledclampwithtestspecimens Dimensionsinmi

    39、llimetres Figure4Specimensize 7 Conditioning Thetestspecimensshallbeconditionedasspecifiedinthestandardforthematerialtested.Intheabsenceofthis information,selectthemostappropriateconditionsfromISO291,unlessotherwiseagreeduponbytheinterested parties,e.g.fortestingathighorlowtemperatures. 8 Procedure

    40、8.1 Inestablishingthebrittlenesstemperatureofamaterial,itisrecommendedthatthetestbestartedata temperatureatwhich50%failureisexpected.Testaminimumoftenspecimensatthistemperature.Ifallofthe specimensfail,increasethetemperatureofthebathby10Candrepeatthetestusingnewspecimens.Ifnoneof thespecimensfail,de

    41、creasethebathtemperatureby10Candrepeatthetestusingnewspecimens.Ifthe approximatebrittlenesstemperatureisnotknown,choosethestartingtemperaturearbitrarily. 8.2 Priortobeginningatest,prepareabathandbringtheapparatustothedesiredstartingtemperature.Ifthe bathiscooledusingdryice,placeasuitableamountofpowd

    42、ereddryiceintheinsulatedtankandslowlyaddthe heat-transfermediumuntilthetankisfilledtoalevel30mmto50mmfromthetop.Iftheapparatusisequipped withaliquid-nitrogenorCO 2 coolingsystemandautomatictemperaturecontrol,followtheinstructionsprovidedby themanufactureroftheinstrumentforpreparingandoperatingthebat

    43、h. 8.3 Mountthetestspecimensfirmlyintheclampingdeviceandsecurethelatterinthetestmachine(see Figure3). NOTE Excessiveclampingforcesmaypre-stresssomematerials,causingprematurefailureduringthetest.Atorque wrenchmaybeusedsothattheforcenecessarytoholdthespecimensintheclampscanbemonitoredandtheminimumforc

    44、e applieduniformlytoeachspecimen.Itisrecommendedthatatorqueof2,8Nmbeusedtosecurethespecimensintheclamps.ISO974:2000(E) 6 8.4 Lowertheclampingdeviceintotheheat-transfermedium.Ifdryiceisbeingusedasacoolant,maintaina constanttemperaturebythejudiciousadditionofsmallquantitiesofdryice.Iftheapparatusisequ

    45、ippedwitha liquid-nitrogenorCO 2 coolingsystemandautomatictemperaturecontrol,followthemanufacturersinstructionsfor settingandmaintainingthetemperature. 8.5 Afterwaitingfor3min 0,5minwhenusingaliquidmedium,or20min 0,5minwhenusingagaseous medium,recordthetemperatureanddeliverasingleimpactonthespecimen

    46、s. 8.6 Removetheclampingdevicefromthetestapparatusandremovetheindividualspecimensfromthe clampingdevice.Examineeachspecimentodeterminewhetherornotithasfailed.Failureisdefinedasthe divisionofaspecimenintotwoormorecompletelyseparatedpiecesorasanycrackinthespecimenwhichis visibletotheunaidedeye.Whereas

    47、pecimenhasnotcompletelyseparated,itshallbebenttoanangleof90 in thesamedirectionasthebendcausedbytheimpactandthenbeexaminedforcracksatthebend.Recordthe numberoffailuresandthetemperatureatwhichthespecimensweretested. NOTE Thetemperatureofaspecimenwhenitisbentwillbesubstantiallyabovethetemperatureatwhi

    48、chthespecimen wasimpacted. Increaseordecreasethetemperatureofthebathinuniformincrementsof2Cor5Candrepeattheprocedure untilthelowesttemperatureatwhichnoneofthespecimensfailandthehighesttemperatureatwhichallofthe specimensfailisdetermined.Usenewtestspecimensforeachtest. 8.7 Carryouttestsatfourormorete

    49、mperaturesintherangeincluding10%to90%failure(0%and100% failurearenotusefulindeterminingT 50 bythegraphicalmethodgivenin9.1). 9 Expressionofresults ThetemperatureT 50 maybedeterminedbyeitherofthefollowingmethods: 9.1 Graphicalmethod Plotthepercentagefailureatanytemperatureagainstthetesttemperatureonarithmeticprobabilitypaperand drawthebeststraightlinethroughtheresults.Readthebrittlenesstemperaturefromthegraphwherethisline intersectsthatfor50%probability. 9.2 Calculationmethod CalculateT 50 usingfollowingequation: TTT S 50 100 1 2 F H


    注意事项

    本文(BS ISO 974-2000 Plastics - Determination of the brittleness temperature by impact《塑料 用冲击法测定脆性温度》.pdf)为本站会员(visitstep340)主动上传,麦多课文档分享仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。 若此文所含内容侵犯了您的版权或隐私,请立即通知麦多课文档分享(点击联系客服),我们立即给予删除!




    关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服 - 联系我们

    copyright@ 2008-2019 麦多课文库(www.mydoc123.com)网站版权所有
    备案/许可证编号:苏ICP备17064731号-1 

    收起
    展开