( jonga kwakhona i-polymer® PTFE kunye ne-polymer® FEP & PFA Specifications ) Iimpawu ze-PTFE zomatshini ziphantsi xa kuthelekiswa nezinye iiplastiki, kodwa iipropati zayo zihlala kwinqanaba eliluncedo kuluhlu olubanzi lobushushu lwe -100 ° F ukuya + 400 ° F (- - 73°C ukuya ku-204°C).
Iimpawu eziqhelekileyo ze-polymer® PTFE Fluoropolymer Resins
Ukumelana nobushushu
Amaqondo obushushu angaphezulu kwe-77°C awalungelanga amacandelo eelastomers ezininzi kunye neeplastiki, kanti i-PTFE imelana nobushushu obuphezulu njenge-260°C.Nangaphantsi kwe-77°C, ukuba iiasidi ezidlekayo kwisinyithi kunye nezinyibilikisi eziphilayo zidityanisiwe, iilitha kunye namalungu e-PTFE ahlala ekhethwa ngenxa yokuba ii-elastomers kunye nezinye iiplastiki zihlala zingenakumelana nokudumba kwe-solvent kunye nokuthamba.
Ukunganyanzeli kweMichiza
Ngokungangeni kweMichiza, sithetha ukuba i-PTFE fluorocarbon resins inokuqhubeka ukudibana nenye into kwaye akukho mpendulo yekhemikhali ebonwayo eyenzekayo.Ngokubanzi, i-PTFE fluorocarbon resins are chemically inert.Nangona kunjalo, le nkcazo, njengazo zonke izinto eziqhelekileyo, kufuneka ifaneleke ukuba ichaneke ngokugqibeleleyo.Isiqinisekiso asiyi kukhokelela ekudidekeni, nangona kunjalo, ukuba umntu ugcina engqondweni iinyaniso ezisisiseko malunga nokuziphatha kwe-PTFE resins.
Isishwankathelo senkcazo esiqhelekileyo sedatha yovavanyo eyahlukeneyo sinokulahlekisa, kuba sinokudibana ngokusisiseko kwiindidi ezahlukeneyo zokuziphatha "kweKhemikhali".Ukuba inkcazo kufuneka icace, kufuneka yahlule phakathi kweekhemikhali ezichanekileyo kunye nezenzo zomzimba ezifana nokufunxa.Inkcazo kufuneka ivumele umsebenzisi ukuba athathele ingqalelo ubudlelwane beempawu ezibonakalayo kunye neekhemikhali ezinokuchaphazela isicelo esithile.
Ngokomzekelo, i-PTFE resins ayiyi kuchaphazeleka ngokuntywiliselwa kwi-aqua regia.Nangona kunjalo, ukuba iqondo lobushushu kunye noxinzelelo lwesiphumo sale reagent liphezulu, ukufunxwa kwamalungu e-reagent kwi-resin kuya kwanda.Ukuguquguquka okulandelayo, okufana nokulahleka koxinzelelo ngequbuliso, kunokuba yingozi emzimbeni ngenxa yokwandiswa komphunga ofakwe kwi-resin.Ngokucacileyo ke, xa sithetha ngeepropathi zeekhemikhali ze-PTFE kufuneka sahlule phakathi kweekhemikhali ezichanekileyo, njengoko sibonakalisile ngokwemiqathango "yokuhambelana kweMichiza" kunye nezenzo zomzimba, ezifana "nokufunxa" kudityaniswe noxinzelelo lomatshini kunye nobushushu.
Ngaphakathi kokusetyenziswa okuqhelekileyo kwamaqondo obushushu, iireyini ze-PTFE zihlaselwa yimichiza embalwa kunokuba kudweliswe iikhemikhali ezihambelana nazo.Ezi reactants ziphakathi kwezona oxidizer ezinobundlobongela kunye neearhente zokunciphisa ezaziwayo.I-sodium ye-Elemental ekunxibelelaneni ngokusondeleyo kunye ne-fluorocarbons isusa i-fluorine kwi-molecule ye-polymer.Le mpendulo isetyenziswa ngokubanzi kwizisombululo ze-anhydrous ukuchola imiphezulu ye-PTFE ukuze iireyini zibe nokuncamathelisa okudityanisiweyo.Ezinye iintsimbi zealkali (i-potassium, i-lithium, njl.) zisabela ngendlela efanayo.
Kwezinye iimeko okanye kufutshane nomda wenkonzo ocetyisiweyo wobushushu obuyi-260°C kwi-TFE & PFA, kunye ne-204°C ye-FEP, iikhemikhali ezimbalwa ezikugxininiso oluphezulu ziye zaxelwa ukuba zisebenza ngokubhekiselele kwi-PTFE.Ukuhlaselwa okufana ne-sodium etch kuye kwaveliswa kwiqondo lokushisa eliphezulu nge-80% ye-NaOH okanye i-KOH, i-hydrides yensimbi efana ne-boranes (umzekelo, i-B2H6), i-aluminium chloride, i-ammonia (NH3), kunye ne-amines ethile (R-NH2) kunye nemines ( R = NH).Kwakhona, uhlaselo olucothayo lwe-oxidative luye lwabonwa yi-70% ye-nitric acid phantsi koxinzelelo kwi-250 ° C.Uvavanyo olukhethekileyo luyafuneka xa iimeko ezinjalo zokunciphisa okanye i-oxidizing zisondela.
Ukufunxa
Ngokuchaseneyo nesinyithi, iplastiki kunye ne-elastomers zifunxa inani elahluka-hlukeneyo lemathiriyeli ezidibana nayo, ngakumbi ulwelo lwendalo.I-Absorptivities kwi-PTFE iphantsi ngokungaqhelekanga, kwaye ukusabela kweekhemikhali phakathi kweplastiki kunye nezinye izinto kunqabile (ngaphandle kwezinto ezimbalwa eziphawulwe ngaphambili).Nangona kunjalo, xa ukufunxa kudityaniswa nezinye iziphumo, le propati inokuchaphazela ukusebenza kwezi resin kwindawo ethile yeekhemikhali.Ngokomzekelo, ukuba utshintsho olukhawulezayo kwiqondo lobushushu okanye uxinzelelo lwenzeka, iimeko zinokudalwa ezonakalisayo ngokwasemzimbeni.Uluhlu olubanzi lobushushu benkonzo ye-PTFE resins lubachanaba kolu hlobo lomonakalo wenyama rhoqo ukuba ezinye iiplastiki.
Ngendlela yenkcazo, makhe siqwalasele uvavanyo "lomjikelezo we-steam" oluchazwe kwimigangatho ye-ATSM * yombhobho odibeneyo.Iisampulu zombhobho ofakwe imigca ziphantsi kwe-0.8MPa (125 psi) umphunga, utshintshana namanzi abandayo anoxinzelelo oluphantsi, nto leyo ebangela ukuguquguquka okuqatha kobushushu kunye noxinzelelo ngokwenene.Oku kuphindwa kwimijikelo eyi-100.Umphunga udale uxinzelelo kunye nokuthambeka kobushushu kwilinen ebangela ukufunxeka komyinge omncinci womphunga othi ujike ube ngamanzi ngaphakathi kodonga lwelinen.Ekukhutshweni koxinzelelo, okanye ekufakweni kwakhona komphunga, amanzi avalelekileyo anokwanda abe ngumphunga abangele i pore yokuqala.Uxinzelelo oluphindaphindiweyo kunye nokuhamba ngebhayisikili ye-thermal kwandisa i-micro pores, ekugqibeleni kubangele i-blister ebonakalayo egcwele amanzi ngaphakathi kwe-liner.Imigangatho ye-ASTM iqaphela ukuba i-blisters ayichaphazeli kakubi ukusebenza kombhobho wepayipi - ubuninzi bokuthintela imichiza lusahamba.
Kukho imilinganiselo eyonakalisayo enciphisa ubunzulu bokudumba.Ukugquma kwe-thermal yombhobho ofakwe intambo okanye isitya kunciphisa i-gradient yobushushu kwi-liner, ngaloo ndlela kuthintela ukunyuswa kunye nokwandiswa okulandelayo kolwelo olufunxayo.Ikwacuthe isantya kunye nobukhulu botshintsho lobushushu, ngaloo ndlela inciphisa amadyungudyungu.Ngaloo ndlela, ngokunciphisa i-resin, i-insulation inokubonelela ngomlinganiselo wokukhusela kwiimeko ezininzi.Ukhuseleko olongezelelweyo lunokunikezelwa ngokusebenzisa iinkqubo zokusebenza okanye izixhobo ezinciphisa izinga lokunciphisa uxinzelelo lwenkqubo okanye ukunyuka kweqondo lokushisa.
Ukugqobhoza
I-Permeation yinto ehambelana ngokusondeleyo nokufunxa, kodwa ikwangumsebenzi wezinye iziphumo zomzimba, ezinje ngokusasazwa kunye nobushushu.Kwiminyaka engaphezu kwama-20 yamava nge-PTFE elayishiwe umbhobho, inani lokusilela okubangelwa kukugqobhoza komphunga otshabalalisayo olandelwa kukuhlwa kwelungu lenkxaso libe limbalwa ngokuphawulekayo.Ubukhulu be-liner ye-1.27 ukuya kwi-6.35mm eyimfuneko kumandla omzimba kumaqondo aphezulu okushisa anciphisa ukugqithiswa ukuya kwinqanaba lokuba ngokuqhelekileyo kuqwalaselwa kancinci.Ngenxa yokuba izinto ezininzi eziguquguqukayo zichaphazela i-permeation, kuyalahlekisa ukusebenzisa idatha yokungena kwilabhoratri efunyenwe ngeefilimu ezicekethekileyo zepolymer njengesiseko sokhetho oluthile lwe-fluoroplastic polymer linings.Ngaphandle kwezinto ezimbalwa, iyantlukwano ekungeneni phakathi kwe-fluoroplastics ayinayo impembelelo encinci ekusebenzeni kwemibhobho eyenziweyo kunye nezixhobo.Ukusebenza kulawulwa ikakhulu ngokuyila, ukuyila kunye nokulawula umgangatho.Ke ngoko, eyona nkxalabo iphambili idla ngokufunxa, kuba le yeyona propati ibonakalisa ukusetyenzwa kweentlaka ze-fluorocarbon kwindawo enikwe imichiza.
Kwiilayini ezingenamida, kubalulekile ukuba isithuba esiphakathi komgca welayini kunye nelungu lenkxaso singene emoyeni, kungekuphela nje ukuvumela ukubaleka komyinge womphunga osisigxina kodwa kuthintelwe ukwanda komoya ovalelekileyo ekuwisweni kwentambo.Kwakhona, ezi zintlu zisetyenziselwa ukuhlolwa kokulawulwa komgangatho wombhobho odibeneyo kwaye njengesixhobo sokukhusela ukubonisa ukuvuza kwimeko yokulimala kwelinen.Ukuwa kwe-Liner kudla ngokubalelwa kukuntywila xa enyanisweni oyena nobangela uphambili kukwenzeka kwevacuum kumjelo wenkqubo.Abavelisi bombhobho odibeneyo bapapasha ukuchasana ne-vacuum kwiqondo lokushisa elilinganisiweyo lobungakanani babo obuhlukeneyo kunye nobukhulu be-liner, kodwa ngamanye amaxesha kuyimfuneko ukukhusela i-vacuum ngokugqithiseleyo ngeempawu zoyilo kunye neenkqubo zokusebenza.
Ixesha lokuposa: Feb-14-2019