I-crystallization melting point ye-PTFE yi-327℃, kodwa i-resin ayikwazi ukuba kwindawo yokunyibilika ide ibe ngaphezu kwe-380℃, kwaye i-viscosity yokunyibilika iphezulu njenge-1 010 Pa * S.Ukongeza, i-PTFE inoxhathiso oluqinileyo lwe-solvent.Ngoko ke, ayinakunyibilika indlela yokucubungula, ayikwazi ukunyibilika kwindlela yokucubungula, ngokuqhelekileyo ukuveliswa kweemveliso zayo kunokufana nesinyithi kunye nokulungiswa kwe-ceramic - isampuli, ukunyanzeliswa komgubo wokuqala, emva koko ukucoca kunye nokucubungula ngoomatshini, okanye ngokubumba i-extrusion, i-isotactic icinezela. ukubumba, ukugquma ukubumba kunye nokubumba i-calendering kunye nezinye iindlela zokucubungula.
I-crystallization melting point ye-PTFE yi-327℃, kodwa i-resin ayikwazi ukuba kwindawo yokunyibilika ide ibe ngaphezu kwe-380℃, kwaye i-viscosity yokunyibilika iphezulu njenge-1 010 Pa * S.Ukongeza, i-PTFE inoxhathiso oluqinileyo lwe-solvent.Ngoko ke, ayinakunyibilika indlela yokucubungula, ayikwazi ukunyibilika kwindlela yokucubungula, ngokuqhelekileyo ukuveliswa kweemveliso zayo kunokufana nesinyithi kunye nokulungiswa kwe-ceramic - isampuli, ukunyanzeliswa komgubo wokuqala, emva koko ukucoca kunye nokucubungula ngoomatshini, okanye ngokubumba i-extrusion, i-isotactic icinezela. ukubumba, ukugquma ukubumba kunye nokubumba i-calendering kunye nezinye iindlela zokucubungula.
1. Ukubumba
Ukubumba ngoku yeyona ndlela isetyenziswa kakhulu yokubumba ye-PTFE.Itekhnoloji yokubumbayinto ethile yokubumba (umgubo, i-granule, i-fibrous material, njl. njl.) kwi-mold yensimbi, kwi--fixed lokushisa, uxinzelelo--indlela yokwenza.Iipolymer ezibunjiweyo azikhawulelwanga bubunzima bazo bemolekyuli, kwaye phantse zonke iiplastiki zinokubunjwa.Iimpawu eziphambili zokubumba zezi;Iindleko eziphantsi, izixhobo ezilula, utyalo-mali oluphantsi, olungakhawulelwanga bubunzima bemolekyuli yeeplastiki ezicwangcisiweyo;Izinto ezingeloncedo kukusebenza kwemveliso ephantsi, ukuqina kwabasebenzi abaphezulu kunye nomgangatho wemveliso ongazinzanga.I-PTFE inobunzima obuphezulu bemolekyuli kwaye ayinamanzi kakhulu.Xa ezinye iindlela zokusetyenzwa zingavuthwanga, iimveliso ze-PTFE zilungiswa ngokubumba kulo lonke ihlabathi.
Ekubumbeni kunokwahlulwa ngokweendlela ezintlanu ngokomahluko wenkqubo ethile: (1) ukucinezela – ukucofa indlela yokucofa (ekwabizwa ngokuba yindlela yokucofa ngokukhululekileyo); (2) ukucofa – ukucofa indlela;(3) ukufudumeza ngokukhawuleza ucinezelo. indlela;(5) ukucofa ngaxeshanye kunye nendlela yokucofa.
2. Indlela yeHydroform
Indlela yoxinzelelo lweHydraulic, eyaziwa ngokuba yindlela yokulinganisa, indlela yoxinzelelo lwe-isobaric okanye indlela yokubumba irabha, kukongeza i-PTFE resin ngokulinganayo phakathi kwengxowa kunye nodonga lokungunda, kwaye emva koko kwingxowa kulwelo (amanzi asetyenziswa ngokuqhelekileyo), uxinzelelo ibhegi yerabha kudonga lokubumba ukwandiswa, ukuhlanganisa i-resin kwaye ibe yimveliso esele yenziwe ngaphambili - indlela.Le ndlela ingasetyenziselwa ukuvelisa i-sleeve yevolumu enkulu, itanki yokugcina ephantsi, i-shell hemispheric, ikholomu yenqaba, i-slab enkulu, njl.Iinzuzo eziphambili zokubumba i-hydraulic yisakhiwo esilula sezixhobo kunye nokubumba - ipompo yamanzi eqhelekileyo ithatha indawo yokushicilela i-tonnage ephezulu, kwaye iimveliso zixinzelelwe ngokulinganayo kunye ne-densely - kubangele ukuveliswa kwamacandelo amakhulu, iimilo ezinzima kunye nesakhiwo esilula se-lining. .
3. Tyhala ukubumba
Uxinzelelo lokutyhala lukwakwaziwa njengokubunjwa kwe-paste extrusion, i-20-30 mesh sieve ye-disperse resin kunye ne-organic additives (i-toluene, i-petroleum ether, i-oyile yokunyibilikisa, umlinganiselo we-resin ubunzima be-1/5) ixutywe kwintlama, iprepress kudonga olungqindilili olungenanto. , emva koko ubeke kumgqomo womatshini wokutyhala, phantsi kokufudumeza kunye ne-plunker push molding.Emva kokumisa kunye nokutshisa kwiqondo lokushisa kwe-360 ~ 380 ° C, ukutyhala okunamandla kunye nokuqina kunye ityhubhu yoxinzelelo kunye neemveliso zebar zifumaneka emva kokupholisa.Iimveliso zokutyhala kunye nokucinezela zikhawulelwe kwintonga enobubanzi be-16mm okanye ngaphantsi kunye nombhobho onodonga oluyi-3mm okanye ngaphantsi.
4. Ukubumba i-Spiral extrusion
I-screw extruder ye-PTFE powder yahlukile kwi-extruder esetyenziswa zezinye iiplastiki ze-thermoplastic.Ukubunjwa kwe-extrusion yeeplastiki eziqhelekileyo ze-thermoplastic kukutyhala izinto phambili ngoncedo lwe-screw rotation, kwaye okwangoku ukucinezela, ukucheba kunye nokuxuba izinto.Izinto eziphathekayo nazo ziyancibilika ngokutshisa okuveliswa ngamandla e-shear kunye nokufudumala kwangaphandle kwe-cylinder yezinto.Nangona kunjalo, i-screw ye-PTFE extruder idlala kuphela indima yokuhambisa kunye nokutyhala, ukuze izinto zidlule kwintloko ye-screw extruder enentloko ephindwe kabini kunye ne-pitch efanayo kunye nobunzulu, kwaye emva koko ingene emlonyeni i-sintering kunye nokupholisa, kunye neefom ezinoxinzelelo olunikezelwa sisixhobo esichasene noxinzelelo lokufikelela kwinjongo eqhubekayo.Kuhlala kunzima ukuqhubekekisa i-PTFE nge-scruder enye yesikrufu.I-coefficient ephantsi ye-friction ye-PTFE powder ibangela i-skidding ngexesha lenkqubo yokutya, eyanciphisa kakhulu amandla okuhambisa i-screw.Kwaye ngenxa yobushushu bokungqubana, kunokwenza ukuba umgubo uncamathele kwisikrufu okanye umgqomo, okwenza ukondla kube nzima ngakumbi kwaye kungazinzi.
Kwiminyaka yakutshanje, i-twin-screw iye yasetyenziswa ekuqhubeni izinto zolu hlobo lukhethekileyo.Umgaqo wayo wokutya uhlukile kulowo we-screw extruder enye, kwaye inomsebenzi wokuthutha ofanelekileyo, onokuyoyisa ingxaki ye-sliding ye-UHMWPE powder kwi-screw kwaye iphucule kakhulu umthamo wokutya we-screw.I-counter-rotating twin-screw extruder inokuxuba okungcono kunye nesiphumo se-homogenization kune-extruder ye-twin-screw extruder efanayo, kodwa ngenxa yamandla ayo amakhulu okwahlukana, isenzo sokucheba kwisithuba se-screw sikhulu, esibangela ukuba izinto zifudumale ngokugqithisileyo. , kunye ne-molecular weight of extruder inokuhla malunga ne-40%.Ukuba i-gap inkulu kwaye i-screw ayibandakanyekanga, izinto eziphathekayo ziya kubambelela kwintsimbi eshushu.Nangona kunjalo, ukusetyenziswa kokujikeleza okufanayo kwe-twin screw extruder, akukho ngxaki enjalo.Izinto ezikwi-extruder ngesenzo sokucheba esincinci, ukwenza iplastikhi yobungakanani obufunekayo bobushushu, konke ukusuka kumthombo wobushushu, kwaye ngaloo ndlela kunokuba nolawulo oluchanekileyo, olunokwenza izinto kwinkqubo yokukhutshwa ukunciphisa ukuthotywa kobushushu, ngaxeshanye umyalelo wokugcina ukuhamba kwezinto eziqhelekileyo kunye nokuzinza empumlweni, ubukhulu becandelo lempumlo yoyilo kufuneka buhambelane nomthamo we-screw yokuhambisa izinto.Isantya seScrew asikhawulezanga, ngokuqhelekileyo malunga ne-10 revolutions ngomzuzu.Ukuze ugweme izinto eziphathekayo ngokukhawuleza zinamathele kumphezulu wesinyithi, ukushisa kwe-extrusion kufuneka kulawulwe ngokungqongqo.
5. Ukubumba i-Plunger extrusion
Plunger extrusion processing iplastiki, processing iplastiki yindlela yamandulo ngokwentelekiso, ukususela ukuvela le nto, abantu baqalisa ukusebenzisa le ndlela ukucubungula iplastiki.I-PTFE ilungiswa nge-plunger extruder ngokucinezela i-resin yobungakanani kwi-inlet yokungunda, ukwenza i-plunger ibuyele kwaye icinezele ukuba ibe yimveliso esele yenziwe ngaphambili.Ngoko emva naphambili, kwisikhuseli somlomo ukwenza i-multi - stage pre - iimveliso zokubumba.Ngenxa yokruthakruthwano phakathi kwe-PTFE resin kunye nokukhuhlana phakathi kwe-PTFE resin kunye nodonga lokungunda, kunye nokwandiswa kwevolumu yemveliso esele yenziwe ngexesha lokucwina ekubunjeni, imveliso elungiselelwe ngaphambili i-sintered kwaye ipholile ibe yinto eqhubekayo phantsi koxinzelelo.Iingenelo zale ndlela zilandelayo: akukho ukucheba okwenzekayo kwinkqubo yokubumba, ubunzima bemolekyuli buyancipha buncinci, umgangatho wemveliso ulungile, kwaye awukhawulelwanga ubunzima be-molecular weight.Nangona kunjalo, ngenxa yendawo encinci yokudibanisa phakathi kwezinto eziluhlaza kunye neengxenye zokufudumeza kwinkqubo yokukhupha, ukusebenza kakuhle kokufudumeza kuphantsi, okukhawulela isantya sokukhupha.
6. Ezinye iindlela zokulungisa;
I-PTFE inokusetyenzwa kwakhona ngokubumba inaliti, ukubumba i-calendering, ukubunjwa kokugquma okanye ukubumba okwesibini.
Ixesha lokuposa: Jul-31-2018