1、BRITISH STANDARD BS EN ISO 294-4:2003 Plastics Injection moulding of test specimens of thermoplastic materials Part 4: Determination of moulding shrinkage ICS 83.080.20 Incorporating Corrigenda Apriland June2003,and November2007National foreword This British Standard is the UK implementation of EN I
2、SO 294-4:2003. It is identical with ISO 294-4:2001, incorporating corrigendum November 2007. It supersedes BS EN ISO 294-4:1998 which is withdrawn. The start and finish of text introduced or altered by corrigendum is indicated in the text by tags. Text altered by ISO corrigendum November 2007 is ind
3、icated in the text by . The UK participation in its preparation was entrusted to Technical Committee PRI/21, Plastics test methods. A list of organizations represented on this committee can be obtained on request to its secretary. This publication does not purport to include all the necessary provis
4、ions of a contract. Users are responsible for its correct application. Compliance with a British Standard cannot confer immunity from legal obligations. BS EN ISO 294-4:2003 This British Standard was published under the authority of the Standards Policy and Strategy Committee on 28 February 2003 BSI
5、 2010 Amendments/corrigenda issued since publication Amd. No. Date Comments 14432 Corrigendum No. 1 3 April 2003 Corrected EN ISO foreword page 14459 Corrigendum No. 2 18 June 2003 National foreword corrected 28 February 2010 Implementation of ISO corrigendum November 2007 ISBN 978 0 580 61879 6EURO
6、PEANSTANDARD NORMEEUROPENNE EUROPISCHENORM ENISO2944 February2003 ICS83.080.20 SupersedesENISO2944:1998 Englishversion PlasticsInjectionmouldingoftestspecimensofthermoplastic materialsPart4:Determinationofmouldingshrinkage (ISO2944:2001) PlastiquesMoulageparinjectiondesprouvettesde matriauxthermopla
7、stiquesPartie4:Dterminationdu retraitaumoulage(ISO2944:2001) KunststoffeSpritzgieenvonProbekrpernaus ThermoplastenTeil4:Bestimmungder Verarbeitungsschwindung(ISO2944:2001) ThisEuropeanStandardwasapprovedbyCENon27December2002. CENmembersareboundtocomplywiththeCEN/CENELECInternalRegulationswhichstipul
8、atetheconditionsforgivingthisEuropean Standardthestatusofanationalstandardwithoutanyalteration.Uptodatelistsandbibliographicalreferencesconcerningsuchnational standardsmaybeobtainedonapplicationtotheManagementCentreortoanyCENmember. ThisEuropeanStandardexistsinthreeofficialversions(English,French,Ge
9、rman).Aversioninanyotherlanguagemadebytranslation undertheresponsibilityofaCENmemberintoitsownlanguageandnotifiedtotheManagementCentrehasthesamestatusastheofficial versions. CENmembersarethenationalstandardsbodiesofAustria,Belgium,CzechRepublic,Denmark,Finland,France,Germany,Greece, Hungary,Iceland,
10、Ireland,Italy,Luxembourg,Malta,Netherlands,Norway,Portugal,SlovakRepublic,Spain,Sweden,Switzerlandand UnitedKingdom. EUROPEAN COMMITTEE FOR STANDARDIZATION COMIT EUROPEN DE NORMALISATION EUROPISCHES KOMITEE FR NORMUNG ManagementCentre:ruedeStassart,36B1050Brussels 2003CEN Allrightsofexploitationinan
11、yformandbyanymeansreserved worldwideforCENnationalMembers. Ref.No.ENISO2944:2003ECORRECTED20030319 Foreword ThetextofISO2944:2001hasbeenpreparedbyTechnicalCommitteeISO/TC61“Plastics“of theInternationalOrganizationforStandardization(ISO)andhasbeentakenoverasENISO 2944:2003byTechnicalCommitteeCEN/TC24
12、9“Plastics“,thesecretariatofwhichisheldby IBN. ThisEuropeanStandardshallbegiventhestatusofanationalstandard,eitherbypublicationof anidenticaltextorbyendorsement,atthelatestbyAugust2003,andconflictingnational standardsshallbewithdrawnatthelatestbyAugust2003. ThisdocumentsupersedesENISO2944:1998. Acco
13、rdingtotheCEN/CENELECInternalRegulations,thenationalstandardsorganizationsof thefollowingcountriesareboundtoimplementthisEuropeanStandard:Austria,Belgium,Czech Republic,Denmark,Finland,France,Germany,Greece,Hungary,Iceland,Ireland,Italy, Luxembourg,Malta,Netherlands,Norway,Portugal,Slovakia,Spain,Sw
14、eden,Switzerlandand theUnitedKingdom. Endorsementnotice ThetextofISO2944:2001hasbeenapprovedbyCENasENISO2944:2003withoutany modifications. NOTENormativereferencestoInternationalStandardsarelistedinAnnexZA(normative). BS EN ISO 2944:2003 EN ISO 2944:2003INTERNATIONAL STANDARD ISO 2944 Secondedition 2
15、0011215 Referencenumber ISO 2944:2001(E) Plastics Injectionmouldingoftest specimensofthermoplasticmaterials Part 4: Determinationofmouldingshrinkage Plastiques Moulageparinjectiondesprouvettesdematriaux thermoplastiques Partie 4:Dterminationduretraitaumoulage BS EN ISO 2944:2003 EN ISO 2944:2003ii B
16、S EN ISO 2944:2003 EN ISO 2944:2003ISO 4921002:4)E( ISO 1002 rllAithgsreservde iii Contents Page 1 Scope . 1 2 Normativereferences . 1 3 Termsanddefinitions 2 4 Apparatus . 3 5 Procedure. 3 6 Expressionofresults 6 7 Precision. 7 8 Testreport 7 Annex A Referencepointsforlengthandwidthmeasurement 8 Bi
17、bliography. 9 iii BS EN ISO 2944:2003 EN ISO 2944:2003ISO 49202:4)E(10 vi ISO 1002 Arllithgrseresvde Foreword ISO(theInternationalOrganizationforStandardization)isaworldwidefederationofnationalstandardsbodies(ISO member bodies). The work of preparing International Standards is normally carried out t
18、hrough ISO technical committees.Eachmemberbodyinterestedinasubjectforwhichatechnicalcommitteehasbeenestablishedhas therighttoberepresentedonthatcommittee.Internationalorganizations,governmentalandnongovernmental,in liaison with ISO, also take part in the work. ISO collaborates closely with the Inter
19、national Electrotechnical Commission(IEC)onallmattersofelectrotechnicalstandardization. InternationalStandardsaredraftedinaccordancewiththerulesgivenintheISO/IECDirectives,Part 3. DraftInternationalStandardsadoptedbythetechnicalcommitteesarecirculatedtothememberbodiesforvoting. PublicationasanIntern
20、ationalStandardrequiresapprovalbyatleast75 %ofthememberbodiescastingavote. AttentionisdrawntothepossibilitythatsomeoftheelementsofthispartofISO 294maybethesubjectofpatent rights.ISOshallnotbeheldresponsibleforidentifyinganyorallsuchpatentrights. InternationalStandardISO 2944waspreparedbyTechnicalCom
21、mitteeISO/TC 61,Plastics,SubcommitteeSC 9, Thermoplasticmaterials. Thissecondeditioncancelsandreplacesthefirstedition(ISO 2944:1997),whichhasbeentechnicallyrevised. ISO 294consistsofthefollowingparts,underthegeneraltitlePlastics Injectionmouldingoftestspecimensof thermoplasticmaterials: Part 1: Gene
22、ralprinciples,andmouldingofmultipurposeandbartestspecimens Part 2: Smalltensilebars Part 3: Smallplates Part 4: Determinationofmouldingshrinkage Part 5: Preparationofstandardspecimensforinvestigatinganisotropy AnnexAofthispartofISO 294isforinformationonly. iv BS EN ISO 2944:2003 EN ISO 2944:2003ISO
23、4921002:4)E( ISO 1002 rllAithgsreservde v Introduction SeeISO 2941. Intheinjectionmouldingofthermoplastics,thedifferencebetweenthedimensionsofthemouldcavityandthoseof themouldedarticlesproducedfromitmayvarywiththedesignandoperationofthemould.Suchdifferencesmay depend on the size of the injectionmoul
24、ding machine, the shape and dimensions of mouldings including any restrictiveactionthismayhaveontheshrinkage,thedegreeanddirectionofflowormovementofthematerialinthe mould,thesizesofthenozzle,sprue,runnerandgate,thecycleonwhichthemachineisoperated,thetemperature of the melt and the mould, and the mag
25、nitude and duration of the hold pressure. Moulding and postmoulding shrinkagearecausedbycrystallization,volumerelaxationandorientationrelaxationofthematerialandbythermal contractionofboththethermoplasticmaterialandthemould.Postmouldingshrinkagemayalsobeinfluencedby humidityuptake. The measurement of
26、 moulding and postmoulding shrinkage is useful in making comparisons between thermoplasticsandincheckinguniformityofmanufacture. Themethodisnotintendedasasourceofdatafordesigncalculationsofcomponents.Informationonthetypical behaviour of a material can be obtained, however, by carrying out measuremen
27、ts at different melt and mould temperatures, injection velocities and hold pressures, as well as at different values of other injectionmoulding parameters.Theinformationthusobtainedisimportantinestablishingthesuitabilityofthemouldingmaterialforthe productionofmouldedarticleswithaccuratedimensions. v
28、 BS EN ISO 2944:2003 EN ISO 2944:20031 Plastics Injectionmouldingoftestspecimensofthermoplastic materials Part 4: Determinationofmouldingshrinkage 1 Scope ThispartofISO 294specifiesamethodofdeterminingthemouldingshrinkageandpostmouldingshrinkageof injectionmouldedtestspecimensofthermoplasticmaterial
29、inthedirectionsparalleltoandnormaltothedirectionof meltflow. ForthedeterminationofshrinkageofthermosetsseeISO 2577 2 . MouldingshrinkageasdefinedinthispartofISO 294excludestheeffectsofhumidityuptake.Thisisincludedin postmouldingshrinkageandthusintotalshrinkage.Forcaseswhenpostmouldingshrinkageiscaus
30、edbythe uptakeofhumidityonly,seeISO 175 1 . Moulding shrinkage as defined in this part of ISO 294 represents the socalled free shrinkage with unrestricted deformationofthecoolingplatesinthemouldduringtheholdperiod.Itmaybeconsideredthereforeasthemaximum valueofanyrestrictedshrinkage. 2 Normativerefer
31、ences Thefollowingnormativedocumentscontainprovisionswhich,throughreferenceinthistext,constituteprovisionsof thispartofISO 294.Fordatedreferences,subsequentamendmentsto,orrevisionsof,anyofthesepublicationsdo notapply.However,partiestoagreementsbasedonthispartofISO 294areencouragedtoinvestigatethepos
32、sibility ofapplyingthemostrecenteditionsofthenormativedocumentsindicatedbelow.Forundatedreferences,thelatest editionofthenormativedocumentreferredtoapplies.MembersofISOandIECmaintainregistersofcurrentlyvalid InternationalStandards. ISO 2941:1996, Plastics Injection moulding of test specimens of ther
33、moplastic materials Part 1: General principles,andmouldingofmultipurposeandbartestspecimens ISO 2943: 2002 ,Plastics Injectionmouldingoftestspecimensofthermoplasticmaterials Part 3: Small plates BS EN ISO 2944:2003 EN ISO 2944:2003 FootnotedeletedISO 49202:4)E(10 2 ISO 1002 Arllithgrseresvde 3 Terms
34、anddefinitions ForthepurposesofthispartofISO 294,thetermsanddefinitionsgiveninISO 2941togetherwiththefollowing apply. 3.1 mouldingshrinkage differenceindimensionsbetweenadrytestspecimenandthemouldcavityinwhichitwasmoulded,boththemould andthetestspecimenbeingatroomtemperaturewhenmeasured NOTE 1 Itise
35、xpressedasapercentage( )ofthemouldcavitydimensionconcerned. NOTE 2 Themouldingshrinkage paralleltothemeltflowdirectionisdeterminedatthemidpointofthewidthofthetest specimen,andthemouldingshrinkage normaltotheflowdirectionatthemidpointofthelength. 3.2 postmouldingshrinkage differenceinthedimensionsofa
36、mouldedtestspecimenbeforeandafterapostmouldingtreatment,measuredat roomtemperature NOTE 1 Itisexpressedinpercent( ). NOTE 2 Thepostmouldingshrinkage paralleltothemeltflowdirectionandthepostmouldingshrinkage normaltothe flowdirectionaredefinedinanalogousfashionto and in3.1. 3.3 totalshrinkage differe
37、nceindimensionsbetweenatestspecimenafterapostmouldingtreatmentandthemouldcavityinwhichit wasmoulded,measuredatroomtemperature NOTE 1 Itisexpressedinpercent( ). NOTE 2 Thetotalshrinkage paralleltothemeltflowdirectionandthetotalshrinkage normaltotheflowdirectionare definedinanalogousfashionto and in3.
38、1. 3.4 cavitypressure pressureofthethermoplasticmaterialinthecavityatanytimeduringthemouldingprocess,measuredcentrallynear thegate NOTE Itisexpressedinmegapascals( ). 3.5 cavitypressureathold cavitypressure(3.4) aftertheendoftheinjectiontime (seeFigure 1) NOTE Itisexpressedinmegapascals( ). S M % S
39、Mp S Mn S P % S Pp S Pn S Mp S Mn S T % S Tp S Tn S Mp S Mn p C MPa p CH 1s t I MPa 2 BS EN ISO 2944:2003 EN ISO 2944:20034A p p a r a t u s 4.1 Type D2ISOmould ,giving platespecimens,asspecifiedinISO 2943: 2002 , subclause 4.1. Referencemarksmaybeengravedinthemouldcavitytofacilitatethemeasurementof
40、thedimensionsofthetest specimensproducedfromthemouldusingopticaltechniques.Suchreferencemarks,ifused,shallbelocatedata distanceof fromtheedgesofthemouldcavity. Itisrecommendedthatsuchmarksbeatmost indepthinordertoensurethattheydonotrestricttheshrinkage processinanyway(seeIntroduction).Pinsinsertedin
41、thecorrectplanehavealsobeenusedsuccessfully. InstallationofapressuresensorP ,recommendedforparts 1 and 3ofthisInternationalStandardseeISO 2941:1996, 4.1.1.4,itemk)andISO 2943: 2002 ,Figure 2,ismandatoryforshrinkagemeasurements. Themouldplatesusedshallberigidenoughtoavoidthemouldedplatesbeingthickert
42、hanthedepthofthecavity, forthewholerangeofholdpressuresthatresultinpositiveshrinkageinlengthorwidth. 4.2 Injectionmouldingmachine ,inaccordancewith4.2ofISO 2943: , butaddingthefollowing tolerancelimits tothelistofoperatingconditionsgivenin4.2.2ofISO 2941:1996: Cavitypressure, 4.3 Measuringequipment
43、,capableofmeasuringthelengthandwidthofeachtestspecimenandofthemould cavityto within ,themeasurements being made betweenthecentres of oppositesides orbetween the oppositeedgesorbetweenpairsofreferencemarks(seeannex A).Whenmeasuringthelengthofatestspecimen, takecaretoincludethe0,5mmhighstepatthegateendofthespecimen.Ifamechanicalinstrumentisused, ensurethatthejawsoftheinstrumentdonotproduceasignificantindentation. Itisrecommendedthatacalibrationplate
