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毕业设计（论文）外文文献翻译文献、资料中文题目：注塑模文献、资料英文题目：TheInjectionMolding文献、资料来源：文献、资料发表（出版）日期：院（部）：专业：班级：姓名：学号：指导教师：翻译日期：2017.02.14外文翻译TheInjectionMolding1、TheinjectionmoldingInjectionmoldingisprincipallyusedfortheproductionofthethermoplasticparts,althoughsomeprogresshasbeenmadeindevelopingamethodforinjectionmoldingsomethermosettingmaterials.Theproblemofinjectionamethodplasticintoamoldcavityfromareservoirofmeltedmaterialhasbeenextremelydifficulttosolveforthermosettingplasticwhichcureandhardenundersuchconditionswithinafewminutes.Theprincipleofinjectionmoldingisquitesimilartothatofdie-casting.Theprocessconsistsoffeedingaplasticcompoundinpoweredorgranularformfromahopperthroughmeteringandmeltingstagesandtheninjectingitintoamold.Afterabriefcoolingperiod,themoldisopenedandthesolidifiedpartejected.Injection-moldingmachineoperation.Theadvantageofinjectionmoldingare：（ⅰ）ahighmoldingspeedadapterformassproductionispossible；（ⅱ）thereisawidechoiceofthermoplasticmaterialsprovidingavarietyofusefulproperties；（ⅲ）itispossibletomoldthreads,undercuts,sideholes,andlargethinsection.2、Theinjection-moldingmachineSeveralmethodsareusedtoforceorinjectthemeltedplasticintothemold.Themostcommonlyusedsysteminthelargermachinesisthein-linereciprocatingscrew,asshowninFigure2-1.Thescrewactsasacombinationinjectionandplasticizingunit.Astheplasticisfedtotherotatingscrew,itpassesthroughthreezonesasshown：feed,compression,andmetering.Afterthefeedzone,thescrew-flightdepthisgraduallyreduced,forcetheplastictocompress.Theworkisconvertedtoheatbyconductionfromthebarrelsurface.Asthechamberinfrontofthescrewbecomesfilled,itforcesthescrewback,trippingalimitswitchthatactivatesahydrauliccylinderthatforcesthescrewforwardandinjectsthefluidplasticintotheclosedmold.Anantiflowbackvalvepresentsplasticunderpressurefromescapingbackintothescrewflight.Theclampingforcethatamachineiscapableofexertingispartofthesizedesignationandismeasuredintons.Arule-of-thumbcanbeusedtodeterminethetonnagerequiredforaparticularjob.Itisbasedontwotonsofclampforcepersquareinchofprojectedarea.Iftheflowpatternisdifficultandthepartsarethin,thismayhavetogotothreeorfourtons.Manyreciprocating-screwmachinesarecapableofhandingthermosettingplasticmaterials.Previouslythesematerialswerehandledbycompressionortransfermolding.Thermosettingmaterialscureorpolymerizeinthemoldandareejectedhotintherangeof375°C～410°C.Thermosettingpartsmustbeallowedtocoolinthemoldinorderorremovethemwithoutdistortion.Thusthermosettingcyclescanbefaster.Ofcoursethemoldmustbeheatedratherthanchilled,aswiththermoplastics.3、BasicUnderfeedMouldAsimplemouldofthistypeisshowninFigure3-1,andthedescriptionofthedesignandtheopeningsequencefollows.Themouldconsistsofthreebasicparts,namely：themovinghalf,thefloatingcavityplateandthefeedplaterespectively.ThemovinghalfconsistsofThemovingmouldplateassembly,supportblock,backingplate,ejectorassemblyandthepinejectionsystem.Thusthemovinghalfinthisdesignisidenticalwiththemovinghalfofbasicmoulds.Thefloatingcavityplate,whichmaybeoftheintegerorinsert-bolsterdesign,islocatedonsubstantialguidepillars（notshown）fittedinthefeedplate.Theseguidepillarsmustbeofsufficientlengthtosupportthefloatingcavityplateoveritsfullmovementandstillprojecttoperformthefunctionofalignmentbetweenthecavityandcorewhenthemouldisbeingclosed.Guidebushesarefittedintothemovingmouldplateandthefloatingcavityplaterespectively.Themaximummovementofthefloatingcavityplateiscontrolledbystoporsimilardevice.Themovingmouldplateissuitablyboredtoprovideaclearanceforthestopboltassembly.Thestopboltsmustbelongenoughtoprovidesufficientspacebetweenthefeedplateandthefloatingcavityplateforeasyremovalofthefeedsystem.Theminimumspaceprovideforshouldbe65mmjustsufficientforanoperatortoremovethefeedsystembyhandifnecessary.Thedesireoperatingsequenceisforthefirstdaylighttooccurbetweenthefloatingcavityplate.Thisensuresthesprueispulledfromthespruebushimmediatelythemouldisopened.Toachievethissequence,springsmaybeincorporatedbetweenthefeedplateandthefloatingcavityplate.Thespringsshouldbestrongenoughtogiveaninitialimpetustothefloatingcavityplatetoensureitmovesawaywiththemovinghalf.Itisnormalpracticetomountthespringsontheguidepillars（Figure3-2）andaccommodatetheminsuitablepocketinthecavityplate.Themajorpartofthefeedsystem（runnerandsprue）isaccommodatedinthefeedplatetofacilitateautomaticoperation,therunnershouldbeofatrapezoidalformsothatonceitispulledfromthefeedplateiscaneasilybeextracted.Notethatifaroundrunnerisused,halftherunnerisformedinthefloatingcavityplate,whereitwouldremain,andbepreventedfromfallingorbeingwipedclearwhenthemouldisopened.Nowthatwehaveconsideredthemouldassemblyinthesomedetail,welookatthecycleofoperationforthistypeofmould.Theimpressionsarefilledviathefeedsystem（Figure3-1（a））andafterasuitabledwellperiod,themachineplatenscommencetoopen.Aforceisimmediatelyexertedbythecompressionsprings,whichcausethefloatingcavityplatetomoveawaywiththemovinghalfaspreviouslydiscussed.Thesprueispulledfromthespruebushbythespruepuller.Afterthefloatingcavityplatehasmovedapredetermineddistance,itisarre