I-Polytetrafluoroethylene, noma i-PTFE, iyinto evame kakhulu esetshenziswa kakhulu cishe kuyo yonke imboni enkulu. Le fluoropolymer enamafutha amaningi futhi esetshenziswa kaningi ithinta wonke umuntu kusukela embonini yezindiza kanye neyezimoto (njengesembozo sokuvikela izintambo) kuya ekunakekelweni kwezinsimbi zomculo (itholakala ku-valve oil brass kanye nezinsimbi zomoya wokhuni ezisetshenziswa ezingxenyeni zazo ezihambayo). Mhlawumbe ukusetshenziswa kwayo okudumile kakhulu kusetshenziswa njengendawo enganamatheli emabhodweni nasemapani. I-PTFE ingakhiwa ibe izingxenye ezibunjiwe; isetshenziswe njengezixhumanisi zamapayipi eziguquguqukayo, imizimba yamavalvu, izivikelo zikagesi, amabheringi, namagiya; futhi ikhishwe njengepayipi.
Ukumelana okukhulu kwamakhemikhali kanye nokungangeni kwamakhemikhali, kanye nezakhiwo ezilula kodwa eziqinile ze-PTFE, kwenza kube nenzuzo enkulu ekukhiqizweni nasekusetshenzisweni kwamadivayisi ezokwelapha. Ngenxa ye-coefficient yayo ephansi kakhulu yokungqubuzana (okuyindlela yezibalo yokuthi ubuso buyashelela ngokumangalisayo),Ipayipi le-PTFEingasetshenziswa ukudlulisa amakhemikhali aqinile noma amathuluzi ezokwelapha okuhlanzeka kwawo okudingeka kugcinwe futhi kudingeke ukuthi kudlule ngokuphephile emzimbeni ngesikhathi sokuhlinzwa. Ipayipi le-PTFE linamafutha amaningi, liqinile futhi lincane kangangokuthi lilungele i-catheter ID eqondisayo (ububanzi bangaphakathi) lapho amathuluzi anjenge-stents, amabhaluni, i-atherectomy, noma amadivayisi e-angioplasty kudingeka ashelele ngokukhululeka ngaphandle kokusongelwa yizihibe noma ukuvinjelwa. Ngenxa yokuthi akukho lutho olunamathela kulezi zinto, lungaphazamisa nekhono lamagciwane nezinye izinto ezithathelwanayo lokunamathela epayipini futhi kubangele izifo ezitholwe esibhedlela.
Zonke lezi zimfanelo ezimangalisayo ze-PTFE zisho ukuthi cishe njalo ihlanganiswa nenye into. Uma isetshenziswa njengesembozo, njenge-gasket yokuvala, noma njengepayipi elinamajakethi e-Pebax nama-ferrule epulasitiki axhumanisayo, kungenzeka ukuthi idinga ukunamathela kwenye into. Kungenzeka ukuthi ukuphawulile lokho esesikushilo kakade: akukho okunamathela ku-PTFE. Izakhiwo ezenza le nto ikhange kangaka ezinkampanini zamadivayisi ezokwelapha zivame ukudala izinselele zokukhiqiza ngesikhathi sokuthuthukiswa nokukhiqizwa komkhiqizo. Ukuthola izembozo, ama-elastomer, nezinye izingxenye zamadivayisi ukuze zinamathele ku-PTFE kuyinselele enkulu futhi kudinga ukulawulwa kwenqubo okuqinile.
Ngakho-ke, abakhiqizi bakwenza kanjani lokhu okusetshenziswe kabanzi, okungaboshelwanga, kube yinto eboshelwa kalula? Futhi bazi kanjani ukuthi kuphathwe kahle noma kulungiselelwe kahle nokuthi empeleni sekulungele ukubopha noma ukumbozwa?
Ukubaluleka Kokuqopha I-PTFE Ngamakhemikhali
Ukuze kuchazwe ukuthi kungani kudingeka ukuqoshwa kwamakhemikhali, kubalulekile ukuqonda ukuthi yini ebangela ukuntuleka kokubopha kwe-PTFE. I-PTFE yakhiwe ngama-chemical bond aqinile kakhulu, okwenza kube nzima ukuthi ihlangane nanoma yini enye, ngisho nangesikhashana.
Njengoba i-PTFE ingasebenzisi amakhemikhali, okusho ukuthi ubuso abuhambisani nanoma yimaphi ama-molecule amakhemikhali ahlangana nawo, kungaba lawo asemoyeni noma lawo aphezu kwezinye izinto, ubuso bawo budinga ukuguqulwa ngamakhemikhali ukuze bunamathele kumakhebula, izinsimbi, noma amapayipi asetshenziswa kuwo.
Konke ukunamathela kuyinqubo yamakhemikhali lapho izendlalelo zama-molecule eziphezulu ezingu-1-5 zobuso zihlangana namakhemikhali akhona ezingqimbeni zama-molecule eziphezulu ezingu-1-5 zanoma yiluphi ubuso obusetshenziswayo. Ngakho-ke, ubuso be-PTFE budinga ukwenziwa busebenze ngamakhemikhali kunokuba bungasebenzi ngamakhemikhali ukuze buhlangane ngempumelelo. Ku-Materials Science, ubuso obusabela kakhulu futhi obufisa ukuhlangana namanye ama-molecule bubizwa ngokuthi “ubuso obunamandla aphezulu.” Ngakho-ke i-PTFE idinga ukususwa esimweni “samandla aphansi”, okuyisimo sayo sokuqala, iye “esinamandla aphezulu,” ikhwalithi ebophayo.
Kunezindlela ezimbalwa zokwenza lokhu, okuhlanganisa ukwelashwa nge-vacuum plasma, futhi kukhona abanye abathi bangafinyelela indawo ebophayo ku-PTFE ngokuyihlikihla, ukuyihlikihla, noma ukusebenzisa ama-primer aklanyelwe ama-PVC noma ama-polyolefin. Kodwa-ke, indlela evame kakhulu futhi efakazelwe ngokwesayensi inqubo ebizwa ngokuthi i-chemical etching.
Ukuqopha kuphula ezinye zezibopho ze-carbon-fluorine ze-PTFE (ezakha wonke ama-fluoropolymer), empeleni, kushintsha izici zamakhemikhali zendawo eqotshiwe, kuyisusa endaweni engasebenzi kahle iye kwenye esebenzayo futhi ekwazi ukusebenzisana ngamakhemikhali nezinye izinto. Indawo ephumayo ayinamafutha amaningi kodwa manje isiyindawo enganamatheliswa, ibunjwe, noma ihlanganiswe nezinye izinto, kanye nokuvumela ukuthi iphrintwe noma iqoshwe kuyo.
Ukuqopha kwenziwa ngokubeka i-PTFE esixazululweni se-sodium, njenge-Tetra Etch evame ukusetshenziswa. Ukusabela kwamakhemikhali okubangelwayo ebusweni kususa ama-molecule e-fluorine emgogodleni we-carbon-fluorine we-fluoropolymer okushiya ama-athomu e-carbon antula ama-electron. Ubuso obuqophayo obusha bunamandla aphezulu kakhulu, futhi uma buvezwa emoyeni, ama-molecule e-oxygen, umhwamuko wamanzi, kanye ne-hydrogen kuvunyelwe ukundiza kuthathe indawo yama-molecule e-fluorine, okuvumela ukubuyiselwa kwama-electron. Le nqubo yokubuyisela iphumela efilimini esabelayo yama-molecule ebusweni evumela ukunamathela.
Enye yezinto ezinhle ngokuqopha amakhemikhali ukuthi iyakwazi ukushintsha izingqimba ezimbalwa eziphezulu zama-molecule bese ishiya yonke ingxenye ye-PTFE iphelele nazo zonke izakhiwo zayo ezihlukile.
Indlela Yokuqinisekisa Ukuvumelana Kwenqubo Yokuqopha Amakhemikhali.
Izakhiwo eziyinhloko ze-PTFE zihlala zifana njengoba ukugqwala kwamakhemikhali kuthinta kuphela izingqimba ezimbalwa eziphezulu zama-molecule. Kodwa-ke, kungase kube nombala onsundu noma onsundu epayipini. Ukwehluka kombala akubonakali kuhlobene nokuthi ubuso bunamathele kangakanani, ngakho ungasebenzisi lokhu kushintsha kombala njengesibonakaliso sangempela sokuthi i-PTFE igqwale kahle kangakanani.
Indlela engcono kakhulu yokwazi ukuthi ukugoba kwakho kudale uhlobo lobuso obufunayo ukusebenzisa indlela esetshenziswa yibo bonke ochwepheshe bokugoba: ukulinganisa i-engeli yokuxhumana namanzi. Le ndlela yenziwa ngokufaka ithonsi lamanzi ahlanzwe kakhulu ku-PTFE bese ulinganisa ukuthi lelo thonsi liziphatha kanjani. Ithonsi elincane lizophakama ngoba likhangwa kakhulu yilo kune-PTFE, noma "lizomanzisa" futhi libe yi-flat ebusweni ngoba likhangwa kakhulu yi-PTFE. Ngokuvamile, lapho i-etch yamakhemikhali iphumelela kakhulu - i-engeli yokuxhumana izoba phansi (, i-flatter the drop). Lokhu kuvame ukubizwa ngokuthi ukuhlola "ukumanzisa" kobuso ngoba, empeleni, uma ubuso bugoqwe kahle futhi ithonsi lamanzi lisakazeka, ingxenye enkulu yobuso iba manzi.
Isithombengenhlaikhombisa umbono weconsi lamanzi ukusuka phezulu kuya phansi (ngaphakathi kwendandatho encane ephuzi neluhlaza okwesibhakabhaka) kushubhu le-PTFE ngaphambi kokuba liqoshwe. Njengoba ubona, unqenqema lweconsi lwenza i-engeli engama-degree angu-95 ngobuso bethubhu.
Isithombe esingenhla sibonisa ithonsi elifanayo lamanzi elifakwe epayipini le-PTFE ngemva kokuqoshwa. Ungabona ukuthi ithonsi lisabalale kakhulu ebusweni bepayipi ngoba indandatho ephuzi neluhlaza okwesibhakabhaka inkulu. Lokhu kusho ukuthi unqenqema lokudonsa ludala i-engeli yokuxhumana ephansi nobuso bepayipi. Futhi uma silinganisa leyo engeli ngedivayisi ye-Surface Analyst, lapho zombili lezi zithombe zithathwe khona, sibona ukuthi, yebo, i-engeli ingu-38 degrees. Uma lokho kuhlangabezana nezidingo zethu ezinqunyiwe zenombolo okudingeka siyishaye ukuqinisekisa ukuthi leli payipi liyabopha, khona-ke sisanda kuqinisekisa ukuthi ubuso buqoshwe ngokwanele.
Ukuze usebenzise kahle kakhulu isivivinyo se-angle yokuxhumana kwamanzi, kubalulekile ukusebenza noSosayensi Wendawo ukuze uqonde ukuthi yiliphi ibanga le-angle elifanele ongalifinyelela ngemva kokusika kwakho. Lokhu kukuvumela ukuthi wakhe inqubo yokubopha ebikezelwayo ngokusekelwe kuncazelo elinganiswayo. Ngoba uma wazi ukuthi udinga ukudala ubuso obune-angle ethile yokuxhumana, khona-ke uyazi ukuthi uma wenza kanjalo, ukunamathela kwakho kuzoba yimpumelelo.
Ngaphezu kwalokho, ukuqinisekisa inqubo yokuqopha ephumelelayo, kubalulekile ukuthatha isilinganiso se-engeli yokuxhumana namanzi ngaphambi kokuba ukuqopha kwenzeke. Ukuthola ukuhlolwa kokuhlanzeka okuyisisekelo kukuvumela ukuthi wazi kahle ukuthi yiziphi izilinganiso ze-etch okudingeka zibe yizo ukuze ufinyelele izidingo zakho ze-engeli yokuxhumana.
Ukugcina I-Etch Yakho
Ukugcinwa kahle kwe-PTFE eqoshiwe kubalulekile enkambisweni yokunamathela ephumelelayo. Ukugcinwa kanye nempahla kuyi-Critical Control Point (CCP). Lawa ma-CCP akhona noma kuphi kuyo yonke inqubo lapho ubuso bento bunethuba lokushintsha, okuhle noma okubi, futhi mhlawumbe ngokungahlosile. I-CCP yokugcina ibalulekile kwi-PTFE eqoshiwe ngoba ubuso obusanda kuhlanzwa ngamakhemikhali buyasabela kakhulu kangangokuthi noma yini ethintana nayo ingashintsha futhi yonakalise umsebenzi wakho.
Umkhuba omuhle kakhulu wokugcina i-PTFE ngemuva kokukhishwa kwe-etch ukusebenzisa iphakheji yokuqala efike ngayo uma ingaphinde ivalwe. Uma lokho kungatholakali, khona-ke izikhwama ezivimba i-UV ziyindlela enhle ehlukile. Gcina i-PTFE kude nomoya nomswakama ngangokunokwenzeka, futhi ngaphambi kokuzama ukuyibopha, qiniseka ukuthi ulinganisa i-contact angle ukuqinisekisa ukuthi igcine ikhono layo lokubopha.
I-PTFE iyinto engavamile enezinhlelo zokusebenza eziningi, kodwa ukuze izuze kakhulu kuyo, kumele iqoshwe ngamakhemikhali bese ihlanganiswa ezimweni eziningi. Ukuqinisekisa ukuthi lokhu kwenziwa ngokwanele, kudingeka kusetshenziswe isivivinyo esizwela izinguquko zamakhemikhali ebusweni. Bambisana nochwepheshe wezinto zokwakha oqonda inqubo yakho yokukhiqiza ukuze athuthukise i-etch yakho futhi afake ukuqiniseka emsebenzini wakho.
Isikhathi sokuthunyelwe: Julayi-17-2023