Chp 6 Flat Knit Product and Knitting Process

WelcometousethePPTaboutWEFTKNITTINGTECHCopyright©Dept.Knitting&ClothingDonghuaUniversity.AllRightsReservedDept.ofKnittingandClothingFlatKnittingmachineChapter6Dept.ofKnittingandClothingObjectsƒFlatknittingmachine–Structurecomponent–Typeofcam»normalcam»splitcardigancamƒComputercontrolledflatknitting–needlebed’slateralmovement–FeedshuttlechangeƒBasicknitstructure–Ripple/Rackedstitch–IntarsiaƒFullfashiontechniqueDept.ofKnittingandClothingContentFlatmachineComputerizedFlatMachineStitchofFlatMachine123Full-fashiononFlatMachine4Dept.ofKnittingandClothingFlatknittingmachine™Needlebed·Two/Flat/Parallel/Latchneedle™Classification·Mechanical(handknittingmachine)·Computercontrolledflatknittingmachine™Applications·Sweaterassemblies,gloves,etc.™Gauge:E3—E18Dept.ofKnittingandClothingƒThetypicalflatmachinehastwostationarybedsoftricksinwhichthelatchneedlesandotherelementsslideduringtheknittingactionandfromwhichtheirbuttsprojectandarecontrolledastheypassthroughthetracksformedbytheangularcamsofabi-directionalcansystemattachedtotheundersideofacarriagewhichwithitsselectedyarncarriers,traversesinareciprocatingmanneracrossthemachinewidth.ƒThereisaseparatecamsystemforeachneedlebed,thetwosystemsarelinkedtogetherbyaboworbridgewhichpassesacrossfromoneneedlebedtotheother.FlatknittingmachineDept.ofKnittingandClothingƒThenumberofgarmentsorpanelssimultaneouslyknittedacrossthemachineisdependentuponitsknittingwidth,yarncarrierarrangement,yarnpathandpackageaccommodation.ƒThesystemsforeachneedlebedaresymmetricallyarrangedsothatknittingandinsomecaseslooptransfermaybeachievedineitherdirectionofcarriagetraverse.ƒTheflatmachineisthemostversatileofweftknittingmachines,itsstitchpotentialincludesneedleselectionononeorbothbeds,rackedstitches,needle-outdesigns,striping,tubularknitting,changesofknittingwidthandlooptransfer.FlatknittingmachineDept.ofKnittingandClothingFlatmachineDept.ofKnittingandClothing™FlatKnittingMachineV.S.WeftCircularKnittingMachineƒAdvantages：·Theflatmachineisthemostversatileofweftknittingmachines·Canchangethetypeconveniently·Canknithalf-cutandfully-knittingproduct,andsavethematerialƒDisadvantages：·Theknittingsystemisfew·Theefficiencyislowbecausetheknittingsystemsisfewandmovementcome-and-goFlatknittingmachineDept.ofKnittingandClothingFlatmachineDept.ofKnittingandClothingFlatmachineDept.ofKnittingandClothingFlatmachineƒV-bedmachineshavetworibgated,diagonallyapproachingneedlebeds,setatbetween90and104degreestoeachotherandgivinganinvertedV-shapeappearance.ƒFlatmachinesdonotnormallyemployholding-downsinkersasthetake-downtensionandtheloopsontheneedlesintheotherbedhelptoholdtheoldloopsdownontheneedlesstems.Dept.ofKnittingandClothingFlatmachineƒLatchbrushesareattachedtothecam-platesofbothneedlebedstoensurethattheneedlelatchesarefullyopened.ƒThecam-carriageseitherslidesorrunsonball-bearingsorwheelsalongguiderails,oneofwhichisfixedoverthelowerendofeachneedlebed.Itispropelledeitherbyhandorfromamotor-drivencontinuousrollerchain.ƒTheyarncarriersarepickeduporleftbehindbythecarriageasrequired,bymeansofdrivingboltsorpistonswhichareattachedtoandarecontrolledfrom,eithermanuallyorautomatically,thecarriagebow.Dept.ofKnittingandClothingFlatmachine™WorkingprincipleƒIt’scompoundofneedlebed,needle,camcase,cam,yarnfeederdeviceandrackandtake-updevice.SliderackFeedertransferLatchopeningbrushesCarrierrodDept.ofKnittingandClothingFlatmachine™Needleandneedlebedƒlatchneedle:·shortbuttneedle·longbuttneedle·longbuttandlongtongueneedleƒneedlebed:·needlegroove·pressdevice·gridshapebarDept.ofKnittingandClothingFlatmachine™Needlegroove,gridshapebar(sinkerloopisheldon),pressdevice(avoidneedlegoingout)Dept.ofKnittingandClothingFlatmachineDept.ofKnittingandClothingFlatmachine™CamcaseandcamƒCamcase·Dropcam1,2,3and4·Guideconvertor5·liftingcam6,7·half-travel8·Pullhandle9·Handle10·Brushrack11Dept.ofKnittingandClothingFlatmachineƒCam·Flatcam:raisingcam/clearingcam(1,2),cardigancam(3),stitchcam(4,5),guidecam(6)·Fancycam：NeedleselectionFullsymmetryDept.ofKnittingandClothingFlatmachineƒPrincipleofneedleselection·3Phases:–Fullyoutofthecam-platesothattheyactoneveryneedlebutt(PositionA)–Partlywithdrawnintothecam-platesothattheymisstheloworshortbuttswhichpassundisturbedacrosstheirface(PositionB)–Fullwithdrawnintothecam-platesothatallbuttspassundisturbedacrosstheirface(PositionC)Dept.ofKnittingandClothingFlatmachinePositionA——Camcomesintoworking,andneedleswithlongandshirtbuttknitstitches.PositionB——Camexitstohalfoftheworkingposition,onlyneedleswithlongshirtcanbeknittingstitches.PositionC——Camexitsabsolutely,andneedleswithlongandshirtbuttknitfloating.Dept.ofKnittingandClothingFlatmachineƒ2-Stagefancyflatmachine·Cam：–Raisingcam(1),stitchcam(2)andguidecam(3)aresimilarwithplatcam.–Twotypesofraisingcam:cardigancam(4)andcrotchcam(5)–whencardigancamisfullwithdrawnintocam-plate,crotchcamwillholdtheneedletoavoidfallingDept.ofKnittingandClothingFlatmachineƒRaisingcamispartlywithdrawnintothecam-plateandcardigancamisfullyoutofcam-plate,sothattheymisstheshortbuttbutactonthelongbuttandknit.ƒRa