News_News_Nanjing Juli Chemical Machinery Co., Ltd. - Extruder (Single Screw Extruder, Double Screw Extruder

About the structure process analysis of twin screw extruder

Next,theeditorofJuliwillgiveyouabriefintroductionaboutthestructureandprocessanalysisofthetwin-screwextruder:??1.Plasticizingarea??Theplasticizingzoneistoheattheinjectedresintoformamoltenstate.Theconditionssuchastheheatingtemperatureandtimeinthisregionarenotparticularlylimitedaslongasthefluoropolymerhavingaspecificunstableterminalgroupisinamoltenstate.Inthelatterhalfoftheplasticizationzone,itispreferabletoprovidedevolatilizationholestoremoveatleastapartofvolatilecomponentsundernormalpressureorreducedpressure.Then,thepartialpressureofvolatilecomponentsinthestabilizationregiondescribedlatercanbereduced,andthestabilizationtreatmentcanbeeffectivelypromoted.??2.Stabilizationtreatmentarea??ThestabilizationzoneistomeltandkneadandconvertspecificunstableendgroupsintoaCF2H.Thestabilizationtreatmentareaispreferablyformedbyusingakneadingdiscwithoutpropulsion.Here,melt-kneadingiscarriedoutinthepresenceofwaterandoxygen.Itcandirectlyintroducepurewater,ionexchangewater,etc.orwatervapor;itcanalsobeaccompaniedbythefluoropolymertobetreated.Theamountofwateraddedisthesameasthenumberofunstableterminalgroups,butitisactuallypreferabletosupplyanexcessamount,forexample,atleast10timestheamount.Thepressureinthestabilizationzoneisgenerallycontrolledat0.2～10MPa,andthesettemperatureiscontrolledat280～430℃.Thetimetomaintainpressurizationisusuallylessthan10minutes.??Accordingtotheprincipleoftheextrudertoremoveunstableendgroups,themelt-kneadinginthestabilizationzoneispreferablycarriedoutinthepresenceofoxygeninadditiontothepresenceofwater.Airisusuallyusedintermsofeconomy.Inthepresenceofoxygen,thecarbongeneratedbythemoltenkneadedproductisalsoburned,whichcaninhibitthecoloringofthefluoropolymer.Oxygenisaninertgastotheunstableterminalgroupscarboxylandfluorinatedacylgroups.Duringtheprocessofmeltingandkneading,itcanimprovethedevolatilizationefficiencyofvolatilecomponents.??Three,devolatilizationarea??Thedevolatilizationzoneremoveshigh-temperaturevolatilecomponentsgeneratedbythedecompositionofspecificunstableterminalgroups.Theabsolutepressurevariesaccordingtothemoltenstateofthemoltenkneadedproductandtheoperatingconditionsofthescrewofthekneader.Generally,thepressureisreducedtothepointwherethemoltenkneadedproductdoesnotintrudeintotheexhaustnozzle.Itcanbe0.01to0.1MPa,andthetemperatureiscontrolledat25O~Claughataround.??Inthepresenceofacertainamountofwaterandoxygen,FEPextrudingthroughatwin-screwextrudercaneffectivelyremovetheunstableterminalgroupsofFEP.SimplifiestheprocessingprocessofFEPunstableendgroupsandsavesproductioncosts.Whentheobtainedstabilizedpolymerismelt-formed,nobubblesorvoidsaregeneratedinthefinishedproduct,anditisnotcolored.?Formoreinformationabouttwinscrewextruders,pleasevisithttp://www.njjl.com/

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What are the technical parameters of a single screw extruder

 2020-07--30

Next,theeditorofJuliwillgiveyouabriefintroductionaboutthetechnicalparametersofthesinglescrewextruder??1.Screwdiameter:referstothediameteroftheoutercircleofthescrew,representedbyD,andtheunitismillimeter(mm).2.Screwlength-to-diameterratio:referstotheratioofthelengthLoftheworkingpartofthescrew(thelengthofthethreadedpart,thatis,thelengthfromthecenterlineofthefeedingporttotheendofthescrew)andthescrewdiameterD,expressedbyL/D.3.Rangeofscrewrotationspeed:referstothemaximumrotationspeedofthescrewtotheminimumrotationspeedofthescrew;nrepresentsthescrewrotationspeed,andtheunitisrevolutionsperminute(r/min).HuahongAnswer4.Powerofthedrivingmotorofthemainscrew:ExpressedbyP,theunitiskilowatt(kW).5.Heatingpowerofextruderbarrel:ExpressedbyE,theunitiskilowatt(kV).6.Theproductioncapacityoftheextruder:expressedbyQ,theunitiskilogramperhour(kg/h).7.Theheightofthecenteroftheextruder:referstothedistancefromthecenterlineofthescrewtotheground,expressedbyH,andtheunitismillimeter(mm).8.Externaldimensionsoftheextruder:referstothetotallength×totalwidth×totalheight,expressedbyL×W×H,andtheunitismillimetersormeters(mmorm)9.Extruderquality:expressedbyW,theunitiskilogramorton(kgort)

Two more effective cleaning agents for starting the double screw extruder

 2020-07--30

Next,Iwillgiveyouabriefintroductiontotwomoreeffectivecleaningagentsforstartingthedoublescrewextruder:????1.Mixture:50%HDPE+50%diatomaceousearth????2.Mixture:HDPE+water+decontaminationpowder.TheHDPEisfedintothescrewattheusualspeedatthemeltingtemperature.Stirthedecontaminationpowderwithwaterinabuckettoformaslurry,andslowlyaddtheslurryfromthemainfeedport.Theseslurriesimpact,rub,andcleanthescrewduetofoaming.????Formoreinformationabouttwinscrewextruders,pleasevisithttp://www.njjl.com/

Introduction to plastic modified granulator

 2020-07--17

1.Thebasicstructureoftheplasticmodifiedgranulator:1.Twin-screwmainengine2.Waterstretchhead3.Conveyorbelt4.Pelletizer5.Silo??2.Basicintroductionofplasticmodifiedgranulatoroftwinscrewgranulator:???Thetwin-screwgranulatorhasagoodplasticizingeffectonthematerialthroughtheshearingcombinationofmanyscrewblocks,andcanbesuitableforvariousmaterialsbychangingthecombinationofscrewelements.

About the deceleration principle of double screw extruder

 2020-07--17

Inmostextruders,thescrewspeedischangedbyadjustingthemotorspeed.Thedrivemotorusuallyrotatesatafullspeedofabout1750rpm,whichistoofastforanextruderscrew.Ifitisrotatedatsuchafastspeed,toomuchfrictionalheatwillbegenerated,andtheresidencetimeoftheplasticwillbetooshorttoprepareauniformandwell-stirredmelt.Thetypicalreductionratioshouldbebetween10:1and20:1.Bothgearsandpulleyblockscanbeusedinthefirststage,butgearsarebestusedinthesecondstageandthescrewispositionedatthecenterofthelastbiggear.Forsomeslow-runningmachines(suchasthetwin-screwusedforUPVC),theremaybethreedecelerationstages,andthemaximumspeedmaybeaslowas30rpmorless(aratioof60:1).Ontheotherhand,someverylongtwinscrewsusedformixingcanrunat600rpmorfaster,soaverylowdecelerationrateandmoredeepcoolingarerequired.

About the temperature principle of twin screw extruder

 2020-07--17

Next,Iwillgiveyouabriefintroductiontothetemperatureprincipleofthetwinscrewextruder:?Extrudableplasticsarethermoplastics,whichmeltwhenheatedandsolidifyagainwhencooled.Therefore,heatisneededduringtheextrusionprocesstoensurethattheplasticcanreachthemeltingtemperature.Sowheredoestheheatofmeltingplasticcomefrom?Firstofall,theweighbridgefeedpreheatingandbarrel/moldheatermayworkandareveryimportantatstartup.Inaddition,themotorinputsenergy,thatis,thefrictionalheatgeneratedinthebarrelwhenthemotorovercomestheresistanceoftheviscousmelttorotatethescrew.Themostimportantheatsourceforallplastics,exceptofcourseforsmallsystems,low-speedscrews,highmelttemperatureplasticsandextrusioncoatingapplications.?Inoperation,itisimportanttorealizethatthebarrelheaterisnotactuallythemainheatsource,anditseffectonextrusionmaybesmallerthanweexpected.Thetemperatureoftherearcylinderismoreimportantbecauseitaffectsthetoothingor