Melt tshuab extrusion txheej txheem yog ib qho - cov txheej txheem, uas siv siab - cua ceev kom tshuab molten thermoplastic resin los ntawm extruder tuag rau lub conveyor los yog li - hu ua coiling screen. Cov txheej txheem no tau muaj txij li xyoo 1950, thiab nws qhov tseem ceeb tau dhau los ua qhov tseem ceeb txij li nws keeb kwm. Cov txheej txheem yooj yim yog qhia hauv daim duab 1, siv lub tshuab ziab khaub ncaws extruder tshwj xeeb uas tsim los tswj thiab tswj cov txheej txheem.
Cov khoom tseem ceeb ntawm cov txheej txheem yog resin pub system, extruder los ua ke, metering twj tso kua mis, yaj tshuab tuag los ua ke, collector thiab winder unit.
Resin muab system
Cov khoom siv raw ntawm cov txheej txheem yaj yog thermoplastic resin nyob rau hauv daim ntawv ntawm cov khoom, uas yog khaws cia rau hauv lub hnab resin thiab thauj mus rau lub extruder hopper los ntawm lub ntiajteb txawj nqus. Muaj ntau ntau yam polymers muaj rau yaj tshuab extrusion. Cov polymers muaj xws li:
Polypropylene PP
polycarbonate
Polybutylene terephthalate
Polyamide PA
Thermoplastic polyurethanes TPU
Elastic polypropylene EPP
Extruder sib dhos
Lub rooj sib txoos extruder tau txais particle pub los ntawm cov khoom noj khoom haus. Lub helical impeller zoo ib yam li Archimedean kauv hla cov khoom los ntawm cov cua sov lub tog raj kheej ntawm lub extruder los ua ke, qhov twg cov khoom hu rau phab ntsa cua sov thiab melted. Muaj peb qhov chaw nyob hauv helical impeller - thaj chaw pub, thaj chaw hloov pauv thiab thaj chaw ntsuas. Qhov chaw pub khoom noj yog ib feem ntawm lub impeller qhov twg cov khoom nkag mus rau hauv extruder thiab pib yaj. Qhov chaw hloov pauv yog tus cwj pwm los ntawm kev txo qhov tob thiab yog siv los ua homogenize thiab compress cov khoom noj polymer. Thaum cov polymer mus txog lub xeev molten, nws raug xa mus rau qhov ntsuas qhov ntsuas, uas ua rau kom lub siab los npaj cov khoom siv tawm los ntawm cov khoom tawg los ntawm kev sib dhos. Muaj ib pab pawg neeg lim dej ntawm qhov tso zis kawg ntawm lub impeller ntsia hlau metering cheeb tsam, uas yog siv los ua lim los cuam tshuam tej av los yog polymer thaiv mus txog lub metering twj.
Metering twj tso kua mis
The output temperature of the molten polymer is 250oC – 300oC and pressurized, and then transmitted to the metering pump. The metering pump is a positive displacement pump designed to deliver a constant volume of clean polymer mixture to the mold assembly, taking into account the process changes in temperature, pressure or viscosity of the molten polymer. There are two counter rotating gears meshing with each other in the pump. When the gears rotate, they draw molten polymer from the suction side or suction side of the pump and deliver it to the discharge side of the pump. The output of the metering pump is then sent to the die assembly.
Melt tshuab mould los ua ke
Muaj peb yam tseem ceeb hauv kev sib dhos tuag - pub faib, tuag taub hau thiab cua manifold. Ob hom kev pub khoom noj feem ntau yog siv; Cov no yog T- hom (tuaj yeem yog tapered lossis undamped) thiab hom hanger. Vim tias qhov sib txawv ntawm cov polymer ntws, cov hanger faib yog ntau dua.
Lub taub hau tuag yog qhov tseem ceeb hauv kev txiav txim siab qhov sib xws ntawm cov khoom siv yaj yaj uas ua los ntawm lub tshuab. Lub taub hau tuag yog lub siab ntev dav dav, hollow, conical hlau ib feem, uas muaj ntau qhov me me los ntawm qhov uas cov molten polymer yuav tsim yaj tshuab nonwovens.
The air manifold provides high{{0}}speed heated air to the extruded fibers, which are output from the head. The air compressor provides compressed air flow, which first drives the gas or electric furnace through the heat exchanger to raise the air temperature to 230 degree C – 360 degree C at a speed of 0.5 – 0.8 sonic speed (560 – 900 ft / s).
tus sau
Tom qab ntawd, cov molten polymer extruded los ntawm qhov tuag lub taub hau yog tsav los ntawm lub siab {{{0}}} cua kub ceev los ntawm huab cua manifold thiab tsim micro fibers thaum lub polymer txuas ntxiv nyob rau hauv cov huab cua ntws (saib daim duab. . 2). Txoj kab uas hla ntawm cov microfibers no txawv ntawm 0.1 microns txog 15 microns. (piv txwv li, cellulose fibers yog hais txog 50 microns nyob rau hauv txoj kab uas hla thiab tib neeg cov plaub hau yog 120 microns nyob rau hauv txoj kab uas hla.) Raws li cov fibers txuas mus, lawv tau tshuab ua ke nyob rau hauv ib tug semi molten lub xeev thiab ntawm lub collector screen. Cov cua kub ntws kuj ua rau cov cua nqus cua los ntawm cov huab cua nyob ib puag ncig thiab pab kom txias thiab ua kom cov khoom sib sau ua ke ntawm cov khoom siv, uas yog cov hlau tensioned txuas nrog lub conveyor. Tom qab cov fibers tau kho lawm, lawv randomly nteg nyob rau hauv lub collector, qhov txhab thiab kev sib raug zoo nrog ib leeg los ua ib tug net. Los ntawm kev hloov cov khoom ceev thiab kev sib cais ntawm lub taub hau tuag thiab cov khoom siv, qhov kev hloov ntawm mesh ceev tuaj yeem pom tau kom hloov mus rau ntau daim ntawv thov. Lub tshuab nqus tsev twj tso kua mis feem ntau yog siv los nqus tsev hauv lub vaj huam sib luag. Qhov no yuav pab tshem tawm cov cua kub ntws thiab txhim kho cov txheej txheem netting ntawm lub collector.
Cua
Cov ntaub ntawv txias los ntawm lub collector yog mob nyob ib ncig ntawm daim duab los qhia core hauv chav winder. Rau ntau hom yaj tshuab nonwovens, muaj txaus adhesion ntawm fibers, yog li cov khoom tsim nyog rau kev siv yam tsis muaj adhesion ntxiv. Hauv qee qhov kev siv, kev ua haujlwm ntxiv ntawm cov khoom yuav tsum tau hloov pauv cov khoom siv. Thaum xav tau kev sib txuas ntxiv, thermal bonding yog ib qho kev siv tshuab, uas tuaj yeem ua rau kom muaj zog ntawm cov khoom, tab sis yuav ua rau muaj zog ntxiv thiab poob ntawm cov ntaub.
Tom qab ib qho kev sib txuas uas yuav tsum tau ua, cov txheej txheem tsim cov yaj tshuab extrusion ntawm tsis yog - ntaub npuag yog ua tiav. Nyob ntawm qhov kawg ntawm kev siv cov khoom, cov txheej txheem ntau lawm tom qab siv tau raws li qhov xav tau, xws li kev sib ntxiv ntawm cov tshuaj tua hluav taws. Cov ntaub uas tsis yog - woven yuav raug muag rau lub converter, uas siv cov ntaub tsis yog - woven li raw khoom los tsim cov khoom lim, kas fes lim, insulating cov ntaub ntawv los yog kev kho mob thiab phais qhov ncauj qhov ntswg tham hauv qab no.
Cov txheej txheem sib txawv
Los ntawm kev hloov qee qhov kev ua haujlwm thiab cov txheej txheem nkag, cov yam ntxwv ntawm cov cua tshuab tsis muaj ntaub qhwv tuaj yeem cuam tshuam thiab tswj tau qee yam. Cov xwm txheej no suav nrog:
Hom polymer siv thiab nws cov khoom siv, xws li qhov hnyav molecular
Kev khiav hauj lwm tej yam kev mob ntawm extruder, xws li kub
Lub geometry ntawm lub taub hau tuag, xws li orifice loj thiab tus naj npawb ntawm orifices
Cov cua kub txaus (kub, ceev)
Qhov deb nruab nrab ntawm lub taub hau tuag thiab lub vijtsam collector
Tus sau ceev