Lub crystalline melting point ntawm PTFE yog 327 ℃, tab sis cov resin yuav tsum siab tshaj 380 ℃ kom nyob rau hauv ib lub xeev molten.Tsis tas li ntawd, PTFE muaj qhov hnyav hnyav heev.Yog li ntawd, nws tsis tuaj yeem siv cov txheej txheem melting lossis kev ua tiav.Feem ntau, kev tsim khoom ntawm nws cov khoom tsuas yog ua tau zoo li hlau thiab ceramic ua.Cov hmoov yog thawj zaug compacted, thiab ces sintered thiab machined, los yog tsim los ntawm extrusion, Isobaric forming, txheej txheej, thiab calendering forming.
Lub crystalline melting point ntawm PTFE yog 327 ℃, tab sis cov resin yuav tsum siab tshaj 380 ℃ kom nyob rau hauv ib lub xeev molten.Tsis tas li ntawd, PTFE muaj qhov hnyav hnyav heev.Yog li ntawd, nws tsis tuaj yeem siv cov txheej txheem melting lossis kev ua tiav.Feem ntau, kev tsim khoom ntawm nws cov khoom tsuas yog ua tau zoo li hlau thiab ceramic ua.Cov hmoov yog thawj zaug compacted, thiab ces sintered thiab machined, los yog tsim los ntawm extrusion, Isobaric forming, txheej txheej, thiab calendering forming.
Compression Moulding
Compression molding yog feem ntauPTFE molding uaTxoj kev tam sim no siv rau PTFE.Cov txheej txheem molding yog ib txoj hauv kev uas qee cov khoom siv molding (hmoov, pellets, cov ntaub ntawv fibrous, thiab lwm yam) tau muab tso rau hauv cov pwm hlau thiab molded ntawm qhov kub thiab txias.Cov polymer ua los ntawm compression molding tsis txwv los ntawm nws qhov hnyav molecular, thiab yuav luag tag nrho cov yas tuaj yeem ua tiav los ntawm compression molding.Cov yam ntxwv tseem ceeb ntawm compression molding yog: tus nqi qis, cov khoom siv yooj yim, kev nqis peev tsawg, thiab tsis txwv los ntawm qhov hnyav molecular ntawm cov txheej txheem yas;qhov tsis zoo yog kev tsim khoom tsawg, kev siv zog ua haujlwm siab, thiab cov khoom tsis ruaj khov.Tus txheeb ze molecular hnyav ntawm PTFE yog siab dhau lawm thiab cov fluidity tsis tshua muaj neeg pluag.Thaum lwm txoj kev ua tsis tiav, lub teb chaws thoob ntiaj teb feem ntau siv compression molding los ua cov khoom PTFE.
Cov txheej txheem tshwj xeeb ntawm compression molding muab faib ua ① xovxwm-sinter-xovxwm txoj kev;② sinter-nias txoj kev;③ ceev cua kub xovxwm txoj kev;④ nias thiab sinter ib txhij.
Hydroforming
Txoj kev hydraulic tseem hu ua txoj kev sib npaug thiab sib npaug ntawm txoj kev sib npaug, uas yog ntxiv PTFE resin tusyees ntawm lub hnab roj hmab thiab cov pwm phab ntsa, thiab tom qab ntawd txhaj cov kua (feem ntau siv dej) rau hauv lub hnab roj hmab, thiab lub hnab roj hmab uas tsim tawm. siab expands mus rau pwm phab ntsa thiab compacts Resin ua ib txoj kev ntawm preforms.Txoj kev no tuaj yeem siv los tsim lub tes tsho loj, cov tso tsheb hlau luam hauv qab, cov plhaub hemispherical, cov kab ntauwd, cov slabs loj, thiab lwm yam, thiab tseem tuaj yeem siv los tsim cov tees, lub luj tshib, cov ntaub ntawv profiled, thiab lwm yam.Cov khoom uas muaj cov duab complex.Lub ntsiab kom zoo dua ntawm hydroforming yog cov qauv yooj yim ntawm cov khoom siv thiab pwm.Ib lub twj tso kua dej zoo tib yam hloov lub siab-tonnage xovxwm.Cov khoom yog uniformly compressed, muaj ib tug zoo sib xws ceev, muaj peev xwm tsim loj-scale Cheebtsam, muaj complex duab, thiab yooj yim hauv ob sab phlu qauv.
Push txoj kev
Pushing kuj hu uamuab tshuaj txhuam extrusionmolding.Lub 20-30 mesh sieved dispersing resin yog tov nrog cov organic additives (toluene, roj av ether, hnyav roj, thiab lwm yam., qhov feem ntawm resin hnyav yog 1/5) los ua ib tug muab tshuaj txhuam.Pre-compressed rau hauv ib tug tuab-walled puag ncig yooj yim dawb paug, ces muab tso rau hauv cov ntaub ntawv xovxwm, thiab siv lub plunger los ua nws nyob rau hauv cua sov.Tom qab ziab, nws yog sintered ntawm qhov kub ntawm 360 ~ 380C, thiab tom qab txias, ib tug tawv thawb lub raj, pas nrig, thiab lwm yam khoom tau txais.Cov khoom thawb yog txwv rau cov pas nrig nrog txoj kab uas hla ntawm 16mm lossis tsawg dua thiab cov kav dej nrog phab ntsa thickness ntawm 3mm lossis tsawg dua.
Muab kauv extrusion molding
Cov ntsia hlau extruder ntawm PTFE hmoov yog txawv los ntawm extruder siv rau lwm yam thermoplastics.Lub extrusion molding ntawm Zengtong thermoplastics yog ua ntej cov khoom siv los ntawm kev sib hloov ntawm cov ntsia hlau, thaum tseem ua lub luag haujlwm ntawm compression, shearing, thiab sib tov., Cov khoom siv kuj yog yaj los ntawm cov cua sov uas tsim los ntawm lub zog sheer thiab cov cua sov sab nraud ntawm cov khoom.Cov ntsia hlau ntawm PTFE ntsia hlau extruder tsuas yog ua lub luag haujlwm ntawm kev xa tawm thiab thawb, kom cov khoom dhau los ntawm lub taub hau ntawm ib leeg-ntsia hlau extruder nrog ob txoj xov, sib npaug ntawm qhov sib npaug thiab qhov tob sib npaug, thiab tom qab ntawd nkag mus rau qhov tuag rau sintering, Txias. thiab molding nrog lub siab muab los ntawm cov khoom siv backpressure kom ua tiav lub hom phiaj tas mus li.Thaum ua PTFE nrog ib tus ntsia hlau extruder, muaj teeb meem loj heev.Vim tias qhov sib txhuam coefficient ntawm PTFE hmoov yog tsawg heev, nws ua rau slippage thaum lub sij hawm pub mis, uas zoo heev txo lub peev xwm conveying ntawm cov ntsia hlau.Tsis tas li ntawd, vim muaj kev sib txhuam thiab kev tsim hluav taws xob, cov hmoov yuav lo rau ntawm cov ntsia hlau los yog lub thoob, ua rau kev noj zaub mov nyuaj thiab tsis ruaj khov.
Nyob rau hauv xyoo tas los no, ntxaib screws kuj tau siv nyob rau hauv kev ua cov ntaub ntawv ntawm no tshwj xeeb xwm.Nws txoj cai pub mis yog txawv ntawm ib leeg-ntsia hlau extruders.Nws muaj qhov zoo ntawm kev xa tawm thiab tuaj yeem kov yeej qhov swb ntawm UHMWPE hmoov hauv cov ntsia hlau.Zoo heev txhim kho cov ntsia hlau pub muaj peev xwm.Ntawm lawv, cov txee-rotating ntxaib-ntsia hlau extruder muaj kev sib xyaw zoo thiab homogenization cuam tshuam ntau dua li tib-rotating ntxaib-ntsia hlau extruder, tab sis vim nws qhov sib cais loj dua, cov nyhuv shearing ntawm qhov sib txawv ntawm cov ntsia hlau yog ntau dua, ua rau cov khoom siv dhau los. thiab extrude.Qhov hnyav molecular ntawm cov khoom tso tawm tuaj yeem raug txo los ntawm 40%.Yog tias lub tshav puam ua kom loj dua thiab cov ntsia hlau tsis koom nrog, cov khoom siv yuav lo rau cov hlau kub.Txawm li cas los xij, kev siv co-rotating ntxaib-ntsia hlau extruders tsis muaj teeb meem saum toj no.Cov nyhuv shearing ntawm cov khoom nyob rau hauv lub extruder yog me me, thiab lub tshav kub yuav tsum tau rau plasticization yog tag nrho cov los ntawm ib tug sab nraud cua sov qhov chaw, yog li nws muaj peev xwm raug tswj kom raug kom lub overheating degradation ntawm cov khoom thaum lub sij hawm extrusion txheej txheem yuav txo tau, thiab nyob rau tib lub sij hawm kom tswj tau qhov ntws ntawm cov ntaub ntawv nyob rau hauv lub tshuab taub hau yog ib txwm thiab ruaj khov, thiab tus tsim ntawm seem loj ntawm lub tshuab taub hau yuav tsum tau yoog rau lub ntim ntawm cov khoom conveyed los ntawm cov ntsia hlau.Kev sib hloov ceev ntawm cov ntsia hlau tsis tuaj yeem ceev ceev, feem ntau nyob ib ncig ntawm 10 revolutions ib feeb.Txhawm rau kom tsis txhob muaj cov khoom siv tam sim ntawd ua rau cov hlau nto, qhov kub ntawm extrusion yuav tsum tau tswj nruj me ntsis.
Plunger extrusion molding
Plunger extrusion molding ua cov yas yog ib txoj hauv kev qub hauv kev ua cov yas.Txij li thaum tshwm sim ntawm cov ntaub ntawv yas, tib neeg tau pib siv txoj kev no los ua cov khoom yas.Txhawm rau ua cov txheej txheem PTFE nrog lub plunger extruder, ntau cov resin yog nias rau hauv pwm, lub plunger yog reciprocated, thiab nws yog nias rau hauv preform.Nyob rau hauv txoj kev no, ntau preforms yog tsim nyob rau hauv tuag.Vim muaj kev sib txhuam ntawm PTFE resin thiab kev sib txhuam ntawm PTFE resin thiab phab ntsa tuag, kuj yog generated.Nyob rau tib lub sij hawm, lub ntim expansion ntawm lub preform thaum sintered nyob rau hauv lub tuag kuj generates kuj, thiaj li hais tias nws yog ib tug preform ntawm ib ntu.Sintering thiab txias nyob rau hauv siab tsim ib tug tas mus li.Qhov zoo ntawm txoj kev no yog: tsis muaj shear thaum lub sij hawm molding txheej txheem, tus txheeb ze molecular hnyav yog txo, qhov zoo ntawm cov khoom yog zoo, thiab nws tsis yog txwv los ntawm tus txheeb ze molecular hnyav, thiab nws muaj peev xwm ua cov loj diameters nrog ib tug zoo. Qhov siab tshaj plaws txoj kab uas hla ntawm 500 hli thiab phab ntsa thickness tsuas yog 3 hli.Yeeb.Txawm li cas los xij, vim qhov chaw sib cuag me me ntawm cov khoom siv raw thiab cov cua sov thaum lub sij hawm xa cov txheej txheem, cov cua kub efficiency yog tsawg, uas txwv qhov ceev ntawm nws extrusion.
Post lub sij hawm: Jun-14-2020