Whythinwallcupmouldsoexpensive?

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  • Whythinwallcupmouldsoexpensive?

    Precio : Gratis

    Publicado por : FGNGHJ65

    Publicado en : 08-10-21

    Ubicación : A Coruña

    Visitas : 4



    Whythinwallcupmouldsoexpensive?


    Whythinwallcupmouldsoexpensive?


    Whythinwallcupmouldpriceissohigh?Generalspeaking,thinwallcupmouldareusingbettersteel,hotrunner,bettercooling,betterventingandbetterdemoldingeffectiveness.


    Thethinwallcupmouldrunsonhighspeedmachinewhichneedswithstandhighpressureduringcupmolding,sothemouldmovingplateandfixedplatethicknessarethickerthancommonmould.Thereneedmanyinterlocksinsidethethinwallmouldtoensureaccuracyandpillarsupporttoavoiddeformandeccentric.Theplasticairlinecupmouldneedusehighhardnesssteel,high-wearandhigh-erosionwithHRC55orabove.Thismeansthinwallmouldsteelcostishigher.


    Thehotrunnerdesignislargerthanthecommonplasticmoulds,andatthesametime,needlimitthemeltresidencetometopreventtheresindegradation.Whenthemouldismult-cavities,thegatingbalanceismuchhigherthanthatofcommonmolds.Whichmeansthinwallcupmouldhotrunnercostishigher.


    Thin-walledproductsdonotwithstandthelargeresidualstressesduetoheattransferirregularitiesliketraditionalwallthicknessparts.Inordertoensurethedimensionalstabilityoftheproduct,andtocontroltheshrinkageandwarpagewithinanacceptablerange,itisnecessarytostrengthenthecoolingofthemoldtoensurethecoolingbalance.Whichmeansneedbettercoolingdesigntoenhancethecoolingeffect,addinghighconductivitymetalinsertswherenecessarytoaccelerateheattransfer,likeBeCuberylliumcopper.Thecoolingcostishigherthancommonmoulds.


    Duetotheshortfillingtimeandhighinjectionspeed,itisveryimportanttofullyexhaustthemold,especiallytheexhaustintheflowfrontgatheringarea,topreventairtrap.Theairisusuallydischargedthroughmouldcores,rams,ribs,studs,andpartingsurfaces.


    Theairlinecupwallsandribsareverythin,theyareveryeasytodamage,andtheshrinkageinthethicknessdirectionissmall,theribsandothersmallstructuresarehardtoseparate,toavoidsticking,thereneedusemoreejectorpinswhenthinwallinjectionmolding.


    Inaword,thinwallmouldstructureismorecomplicatedthancommonmoulds.That’swhythethinwallcupmouldissoexpensive.


    Cutlerymouldexhaustproblem


    Intheprocessofproducingcutlerymould,sometimeswillhaveunfilledparts,airbubblesetc,thisiscausedbyairexhaust.


    1.Thesourceofairintheinjectioncutlerymold.


    (1)Theaircontainedinthegatingsystemandthemouldcavity.(2)Somerawmaterialscontainmoisturethatisnotremovedbydrying,andtheyarevaporizedintowatervaporatahightemperature.(3)Airgeneratedbydecompositionofsomeunstableplasticsduetoexcessivetemperatureduringinjectionmolding.(4)Airformedbyvolatilizationorchemicalreactionofcertainadditivesinplasticrawmaterials.


    Poorexhaustoftheknifeandforkmoldwillbringaseriesofhazardstothequalityoftheplasticparts.Themainperformanceisasfollows:


    (1)Intheinjectionmoldingprocess,themeltwillreplacetheairinthecavity.Iftheairisnotdischargedintime,themeltfillingwillbedifficult,resultingininsufficientinjectionvolumetofillthecavity.


    (2)Excludingtheunsatisfactoryairwillformahighpressureinthecavityandpenetrateintotheplasticinsideunderacertaindegreeofcompression,resultinginqualitydefectssuchaspores,voids,tissuesparseness,andsilverstreaks.


    (3)Duetothehighcompressionoftheair,thetemperatureinthecavityrisessharply,whichcausesdecompositionandburningofthesurroundingmelt,causinglocalcarbonizationandcharringoftheplasticpart.Itmainlyoccursatthejunctionofthetwomeltsatthegateflange.


    (4)Theairisnotwellremoved,sothatthemeltvelocityenteringeachcavityisdifferent,soflowmarksandfusionmarksareeasilyformed,andthemechanicalpropertiesoftheplasticpartsarelowered.


    (5)Duetotheobstructionofairinthecavity,thefillingspeedwillbereduced,themoldingcyclewillbeaffected,andthetaxationefficiencywillbereduced.


    Distributionofbubblesinplasticparts


    (1)Thebubblesgeneratedbytheaccumulationofairinthemouldcavityofthecutleryspoonareoftendistributedontheoppositepartofthegate.


    (2)Bubblesgeneratedbydecompositionorchemicalreactionintheplasticrawmaterialaredistributedalongthethicknessoftheplasticpart.


    (3)Thebubblesgeneratedbythevaporizationofresidualwaterintheplasticrawmaterialareirregularlydistributedontheentireplasticpart.


    Injectionmoldingisaprocessinwhichamoltenplasticisinjectedintoaclosedmoldhavingarelativelylowtemperaturethroughanozzleunderhighpressure.Boththermoplasticsandthermosetscanbeinjectionmolded.Itcanbeusedtomakevariousbox-typepackagingbucketsandpails,suchasvariouspailsboxesandsmallboxesmould.Forbox-typepackagingcontainers,Chinabucketmoldmanufacturerswillconsiderthefollowingaspectsinbucketmouldstructuraldesign.


    1.Thewallthicknessofthebucketmould


    Thedesignofthewallthicknessmainlyconsidersthreeaspects:oneisthickness;theotherisuniformity;thethirdisgentletransition.


    1Thickness:Thewallthicknessofthebucketismainlydeterminedbyitsuse,plastictype,structureandsoon.Forthermoplastics,generallynotlessthan0.6mm,oftenchoose2~4mm;forthermosettingplastics,becauseofitspoorfluidity,thethicknessislarger,thesmallpiecesare1.6~2.5ram,thelargepiecesare3.2~8mm,themaximumisnomorethan10mm.


    2Uniformity:Theuniformityofwallthicknesshasagreatinfluenceonthequalityofthebucket.Ifthethicknessdifferenceofabucketistoolarge,theshrinkagewillbeuneven,causingdefectssuchasdeformationandcrack.Therefore,thestructureshouldbedesignedwithanequalthicknessstructure.


    3Smoothtransition:Insomebuckets,somepartsmusthavedifferentthicknessesduetostructuralrequirements,suchasthebucketturningpoint.Atthistime,agentletransitionshouldbeadoptedtoavoidthesuddenchangeofthesection.


    2.Improvestiffnessofthebucket


    Theplasticisrelativelyflexible,thebucketismadeofpoorrigidity,andtheturnoverboxtypecontainersometimeshasalargeloadcapacity,sovariousmeasuresforimprovingtherigidityshouldbeadoptedinthestructure.


    1Addreinforcement:Reinforcementcanenhancethestrengthandrigidityofthecontainer.Thebasicrequirementsfortheribsare:thenumbershouldbemore,thewallthicknessshouldbethin,theheightshouldbeshort,andtheslopeshouldbesufficient.Thebottomoftheribshouldbeacirculararctransition.Thedirectionoftheribshouldbeconsistentwiththeflowdirectiontoimprovetheplastic.toughness;


    2Improvetheshape:thebox-shapedbucketismostlyrectangularthin-walledparts,whichareeasytobedeformed.Variousreinforcementmeasuresshouldbetakentoslightlyextendthefoursidewallsofthebuckettoimprovetherigidity;itisastripshapeonthesidewalltopreventdistortion.Enhancement;edgereinforcementattheedgeofthebuckettopreventdeformationofthemouth;bottomreinforcementatthebottomofthebucketdesignedinacorrugated,archedshape.


    3Reasonablesupport:Thebottomareaofthebox-shapedbucketislarge,butitisunreasonabletousethewholebottomsurfaceasthesupport.Becausethebottomisslightlycurved,itisnotflat.Therefore,thesurfacesupportshouldbechangedintoalinesupportorapointsupport,andtheconvexsidesupport(ie,theline)Support);raisedfootsupport(iepointsupport);theheightoftheprotrusionisgenerally0.3~0.5mm.


    4Corner:Thecorneristheintersectionoftwofacesorthreefaces.Regardlessoftheshapeofthebucket,theintersectionofthefacesmustberounded,whichcangreatlyimprovetherigidityofthebucketandimprovetheplasticfillingmodel.Sex,andcandispersestressandreducedeformation.


    3.Demouldingslope


    Inordertofacilitatethedemoldingofthemoldedpart,asuitabledraftanglemustbeconsideredwhendesigningthebucket.Thedraftistoosmall,thedemouldingisdifficult,andthesurfaceofthebucketisdamaged;ifitistoolarge,thedimensionalaccuracyisaffected.


    Thedraftanglevariesdependingontheshapeoftheplasticpart,thetypeofplastic,themoldstructure,thesurfaceroughness,themoldingmethod,andthelike.Generallyspeaking,thecommonlyusedslopeoftheplasticpartalongthedemoldingdirectionis1o~1.5o,andtheminimumisnotlessthan0.5o.

    Householdmoldsareaformoffungus.Therearemanydifferenttypes,andtheycanoccurbothindoorsandoutdoors.


    Moldsproducespores,whichspreadbyfloatingaroundintheair.Moldsporesarepresentinallindoorenvironments.Thereisnowaytopreventspores,andtheycanpersistinconditionswheremolditselfcannotgrow.


    Moldsporesthriveinenvironmentsthataremoistandwarm,sowhentheylandonadampspot,theybegintogrow.


    Moldscangrowonavarietyofdifferentsurfaces,includingfabric,paper,wood,glass,andplastic.Astheygrow,theymaydigestthematerialtheyaregrowingon.




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