Indawo yokunyibilika yekristale ye-PTFE yi-327℃, kodwa i-resin kufuneka ibe ngaphezulu kwe-380℃ ukuze ibekwimo enyibilikayo.Ukongeza, i-PTFE inoxhathiso olomeleleyo lwe-solvent.Ke ngoko, ayinakukwazi ukusebenzisa ukunyibilika kokunyibilika okanye ukusetyenzwa kwe-dissolution.Ngokuqhelekileyo, ukuveliswa kweemveliso zayo kunokwenziwa kuphela njengesinyithi kunye ne-ceramic processing.Umgubo uqala ukudityaniswa, kwaye emva koko u-sintered kunye nomatshini, okanye wenziwa nge-extrusion, i-Isobaric eyenza, i-coating forming, kunye ne-calendering forming.
Indawo yokunyibilika yekristale ye-PTFE yi-327℃, kodwa i-resin kufuneka ibe ngaphezulu kwe-380℃ ukuze ibekwimo enyibilikayo.Ukongeza, i-PTFE inoxhathiso olomeleleyo lwe-solvent.Ke ngoko, ayinakukwazi ukusebenzisa ukunyibilika kokunyibilika okanye ukusetyenzwa kwe-dissolution.Ngokuqhelekileyo, ukuveliswa kweemveliso zayo kunokwenziwa kuphela njengesinyithi kunye ne-ceramic processing.Umgubo uqala ukudityaniswa, kwaye emva koko u-sintered kunye nomatshini, okanye wenziwa nge-extrusion, i-Isobaric eyenza, i-coating forming, kunye ne-calendering forming.
Ukubunjwa koxinzelelo
Ukubumba ukunyanzeliswa kokona kuninziPTFE ukusetyenzwa kokubumbaindlela esetyenziswa ngoku kwi-PTFE.Inkqubo yokubumba yindlela apho izinto ezithile zokubumba (ii-powders, iipellets, izinto ze-fibrous, njl.) zifakwe kwi-mold yensimbi kwaye zibunjwe kwiqondo lokushisa elithile kunye noxinzelelo.I-polymer ecutshungulwayo ngokubunjwa koxinzelelo ayikhawulelwanga bubunzima bayo bemolekyuli, kwaye phantse zonke iiplastiki zinokucutshungulwa ngokubunjwa koxinzelelo.Iimpawu eziphambili zokubunjwa koxinzelelo zezi: ixabiso eliphantsi, izixhobo ezilula, utyalo-mali oluphantsi, kwaye alukhawulelwanga ngobunzima bemolekyuli yeplastiki esetyenzisiweyo;izinto ezingeloncedo kukungaphumeleli kwemveliso, ukuxinana kwabasebenzi, kunye nomgangatho wemveliso ongazinzanga.Ubunzima bemolekyuli be-PTFE buphezulu kakhulu kwaye ulwelo lubi kakhulu.Xa ezinye iindlela zokusetyenzwa zingekavuthwa, amazwe kwihlabathi jikelele asebenzisa ucinezelo lokubumba ukwenza iimveliso zePTFE.
Inkqubo ethile yokubumba ucinezelo yahlulwe yaba ① cinezela-sinter-cofa indlela;② indlela yokucofa sinter;③ indlela yokufudumeza ngokukhawuleza;④ cofa kwaye sinter ngaxeshanye.
I-Hydroforming
Indlela ye-hydraulic ikwabizwa ngokuba yi-equalization method kunye nendlela yoxinzelelo elinganayo, eyokongeza i-PTFE resin ngokulinganayo phakathi kwebhegi yerabha kunye nodonga lokungunda, kwaye emva koko utofe ulwelo (amanzi asetyenziswa ngokuqhelekileyo) kwibhegi yerabha, kunye nebhegi yerabha evelisa ulwelo. uxinzelelo luyanda eludongeni lokungunda kunye ne-compact Resin iba yindlela ye-preforms.Le ndlela ingasetyenziselwa ukwenza imikhono emikhulu, iitanki zokugcina ezisezantsi, amaqokobhe e-hemispherical, iikholamu zenqaba, ii-slabs ezinkulu, njl.Iimveliso ezinemilo enzima.Inzuzo ephambili ye-hydroforming yisakhiwo esilula sezixhobo kunye nokubunjwa.Impompo yamanzi eqhelekileyo ithatha indawo yomatshini wokushicilela onetoni ephezulu.Imveliso ixinaniswe ngokufanayo, inoxinaniso olungaguqukiyo, inokuvelisa amacandelo amakhulu, ineemilo ezintsonkothileyo, kunye nezakhiwo ezilula zelinen.
Ukutyhala
Ukutyhala kukwabizwa ngokubacoma i-extrusionukubumba.I-20-30 ye-mesh sieved sieved resin dispersing resin ixutywe kunye ne-organic additives (i-toluene, i-petroleum ether, i-solvent oil, njl., umlinganiselo we-resin weight 1/5) ukwenza i-paste.Icinezelwe kwangaphambili ibe yingqukuva etyebileyo engenanto engenanto, emva koko uyibeke kwisixhobo sokushicilela, kwaye usebenzise iplunger ukuyibumba phantsi kobushushu.Emva kokumisa, i-sintered kwiqondo lokushisa lama-360 ~ 380C, kwaye emva kokupholisa, ityhubhu yokutyhala eqinile, intonga kunye nezinye iimveliso zifunyenwe.Iimveliso zokutyhala zikhawulelwe kwiintonga ezinobubanzi obuyi-16mm okanye ngaphantsi kunye nemibhobho enobunzima obuyi-3mm okanye ngaphantsi.
Spiral extrusion ukubumba
I-screw extruder ye-PTFE powder yahlukile kwi-extruder esetyenziselwa ezinye i-thermoplastics.Ukubunjwa kwe-extrusion ye-Zengtong thermoplastics kukuqhubela phambili izinto ngokujikeleza kwe-screw, ngelixa lidlala indima yoxinzelelo, ukucheba kunye nokuxuba., Izinto eziphathekayo ziphinda zincibilike ngokushisa okwenziwa ngamandla amakhulu kunye nokufudumala kwangaphandle kwezinto.I-screw ye-PTFE screw extruder idlala kuphela indima yokuhambisa kunye nokutyhala, ukwenzela ukuba izinto zidlule kwintloko ye-screw extruder enemisonto ephindwe kabini, i-pitch elinganayo kunye nobunzulu obulinganayo, kwaye ingena kwi-die for sintering, Ukupholisa. kunye nokubumba ngoxinzelelo olunikezwa sisixhobo sokubuyela umva ukufezekisa injongo eqhubekayo.Xa kusetyenzwa i-PTFE nge-screw extruder enye, ubunzima obukhulu buhlala budibana.Ngenxa yokuba i-coefficient ye-friction ye-PTFE powder iphantsi kakhulu, ibangela i-slippage ngexesha lenkqubo yokutya, eyanciphisa kakhulu umthamo wokuhambisa isikrufu.Ukongeza, ngenxa yengxabano kunye nokuveliswa kobushushu, umgubo unokunamathela kwi-screw okanye umgqomo, okwenza ukutya kube nzima kwaye kungazinzi.
Kwiminyaka yakutshanje, izikrufu ezingamawele ziye zasetyenziswa ekusetyenzweni kwezinto zolu hlobo lukhethekileyo.Umgaqo wayo wokutyisa wahlukile kulowo we-single-screw extruders.Inefuthe elihle lokuhambisa kwaye inokoyisa i-slippage ye-UHMWPE powder kwi-screw.Ukuphucula kakhulu umthamo wokutyisa izikrufu.Phakathi kwazo, i-counter-roting twin-screw extruder ineempembelelo ezingcono zokuxuba kunye ne-homogenization kune-extruder ye-twin-screw ejikelezayo efanayo, kodwa ngenxa yamandla ayo amakhulu okwahlukana, umphumo wokucheba kwi-screw gap mkhulu, ubangela ukuba izinto zifudumale. kunye nokukhupha.Ubunzima bemolekyuli yezinto eziphumayo zingancitshiswa malunga ne-40%.Ukuba intendelezo yenziwe ibe nkulu kwaye izikhonkwane azibandakanyekanga, izinto eziphathekayo ziya kubambelela kwintsimbi eshushu.Nangona kunjalo, ukusetyenziswa kwe-twin-screw extruders ezijikelezayo azinayo iingxaki ezingentla.Umphumo wokucheba wezinto eziphathekayo kwi-extruder uncinci, kwaye ubushushu obufunekayo kwi-plasticization buvela kumthombo wangaphandle wokufudumeza, ngoko unokulawulwa ngokuchanekileyo ukwenzela ukuba ukuchithwa kokushisa kwezinto ngexesha lenkqubo ye-extrusion kungancitshiswa, kwaye ngexesha elifanayo ukugcina Ukuhamba kwezinto kwintloko yomatshini kuqhelekileyo kwaye kuzinzile, kunye noyilo lobungakanani becandelo lentloko yomatshini kufuneka lutshintshwe kumthamo wezinto ezihanjiswa yi-screw.Isantya sokujikelezisa isikrufu asinako ukukhawulezisa naso, ngokufuthi sijikeleze i-10 revolutions ngomzuzu.Ukuze ugweme izinto eziphathekayo ngokukhawuleza zinamathele kwindawo yesinyithi, ukushisa kwe-extrusion kufuneka kulawulwe ngokungqongqo.
Ukubumba i-Plunger extrusion
IPlunger extrusion yokubumba iiplastiki zokusetyenzwa yindlela yakudala ekusetyenzweni kweplastiki.Ukususela ekuveleni kwezinto zeplastiki, abantu baye baqala ukusebenzisa le ndlela yokucubungula iiplastiki.Ukusetyenzwa kwe-PTFE nge-plunger extruder, i-resin yobungakanani icinezelwe kwi-mold, i-plunger iyabuyiselwa, kwaye icinezelwe ibe yi-preform.Ngale ndlela, ii-preforms ezininzi zenziwe kwi-die.Ngenxa yokungqubana phakathi kwe-PTFE resin kunye nengxabano phakathi kwe-PTFE resin kunye nodonga lokufa, ukuchasana kuveliswa.Kwangaxeshanye, ukwandiswa umthamo preform xa sintered kwi die nako kuvelisa ukuchasana, ukuze kube preform yecandelo elinye.I-Sintering kunye nokupholisa phantsi koxinzelelo lwenza yonke into eqhubekayo.Iingenelo zale ndlela zezi: akukho ukucheba ngexesha lenkqubo yokubumba, ubunzima bemolekyuli buncitshisiwe, umgangatho wemveliso ulungile, kwaye awukhawulelwanga bubunzima bemolekyuli, kwaye inokuqhuba iidayamitha ezinkulu nge ubukhulu bobukhulu be-500mm kunye nobukhulu bodonga yi-3mm kuphela.Umbhobho.Nangona kunjalo, ngenxa yendawo encinci yokudibanisa phakathi kwezinto eziluhlaza kunye nenxalenye yokufudumeza ngexesha lokuthumela, ukusebenza kakuhle kokufudumeza kuphantsi, okukhawulela isantya sokukhupha kwayo.
Ixesha lokuposa: Jun-14-2020