Kangangeminyaka eliqela i-fluoropolymers idlale indima ebalulekileyo kwimichiza kunye namashishini afanayo ukukhusela izityalo kunye nezixhobo ekuhlaselweni kweekhemikhali luluhlu olubanzi lweendaba ezinobundlobongela.Oku kungenxa yokuba zibonelela kakhulu ngokuxhathisa imichiza kunye nokuzinza kwe-thermal kunezinye iiplastiki okanye izinto ze-elastomeric. Kwiminyaka emininzi i-fluoropolymers idlale indima ebalulekileyo kwimichiza kunye namashishini afanayo ukukhusela izityalo kunye nezixhobo ekuhlaselweni kweekhemikhali ngoluhlu olubanzi lokundlongondlongo. amajelo eendaba.Oku kungenxa yokuba banikezela ngcono ngokuxhathisa imichiza kunye nozinzo lobushushu kunezinye iiplastiki okanye imathiriyeli ye-elastomeric.
Ukulandela uphuhliso lwe-PTFE, ukuqaliswa kwe-melt-processable fluorinated ethylene-propylene (FEP) ngo-1960 kwavula iindawo ezintsha ngokupheleleyo zesicelo.I-PFA, i-polymer ye-perfluoro-alkoxy esetyenziswe ngempumelelo iminyaka eyi-20 njengempahla ye-lining, ngoku ilandela i-thermoplastic ye-PTFE, kunye nokuchasana kwe-thermal kunye neekhemikhali ezilinganayo kunye neempawu eziphezulu ngokubhekiselele ekusebenzeni, ukuguquguquka, ukuchasana kwe-permeation kunye namandla omatshini. .
Kwishishini lemichiza, zombini i-fluoropolymers - i-PTFE kunye ne-PFA - isetyenziswa ikakhulu kwifom ye-linings.Kwiimilo ezilula, ezinjengemibhobho, ukugoba, ii-T-pieces okanye ii-joints zokunciphisa, i-PTFE isetyenziswa ngokubanzi;isetyenziswa ngendlela yokuncamathelisa i-extrusion, i-ram extrusion okanye i-tape wind-ing.Kwezi nkqubo kwenziwa i-pre-form ye-PTFE;Oku ke kuye kufakwe i-sintered kwaye ifakwe kwi-workpiece yentsimbi.Ukusebenzisa i-PTFE kumgca weendawo zetsimbi zemilo entsonkothileyo, efana neevalvu kunye neempompo, kunzima ngakumbi.Ukubumba i-Isostatic ke yindlela ekhethwayo.Kule PTFE powder izaliswe kwisithuba esidalwe phakathi kwentsimbi yokusebenza-intsimbi kunye nebhegi yerabha eyenziwe ngokukhethekileyo ukuba ingene kwimilo yendawo ekuza kufakwa kuyo.I-powder i-pre-compressed, emva koko icinezelwe ngokubanda kwimo efunwayo.Okokugqibela, ibhegi yerabha iyasuswa kwaye indawo enemigca itshiswe kwi-oveni engaphezulu kwe-360?C (680?F).
I-PFA, i-thermoplastic material ene-melting point echazwe kakuhle, inokucutshungulwa ngendlela yokudlulisa ukubunjwa okanye ukubunjwa kwenaliti.I-granulate iyancibilika kwi-melt pot okanye kwi-extruder kwaye inyanzeliswe kwisixhobo esishushu ngumshini wokunyathelisa we-hydraulic.
Le ndlela yenza ukuba ukutyeba kodonga oluchaneke kakhulu kuphunyezwe, ngokunyamezela?0,5 mm, nakwi-tight radii nakwi-undercuts.Ngokuqhelekileyo akukho kugqiba ngoomatshini okudingekayo, ngaphandle kokususa i-sprue kunye nokugudisa ubuso bokukhwelana kweeflange.
Xa usebenzisa ukubunjwa kwe-isostatic, nangona kunjalo, ubungakanani obukhulu bokugqiba oomatshini bufunekayo - kuxhomekeke kwinqanaba lobunzima bomzobo oza kuzaliswa - ukufezekisa imilinganiselo efunwayo ngokuchanekileyo.
Ukulingana kodonga lobungqimba kunokwahluka ngakumbi, ngakumbi kwimeko yeemilo ezintsonkothileyo ezifana nezindlu zevalvu.
Ukufunxwa kunye nokuNgqobhoza
Ngokungafaniyo neentsimbi, iiplastiki kunye nee-elastomers zifunxa inani elahlukileyo lemithombo yeendaba ezidibana nazo.Oku kuhlala kunjalo kwiikhompawundi eziphilayo.Ukufunxa kunokulandelwa kukugqobhoza kudonga lodonga.Nangona oku kungafane kuqwalaselwe ngeefluoropolymers, kunokuchaswa kukutyeba kodonga okwandisiweyo okanye ngokufakela izixhobo zokukhupha isithuba esiphakathi kwelayini ye-fluoropolymer kunye nodonga lwentsimbi.Kubonakaliswe ngokucacileyo ukuba ngokubhekiselele kwi-permeation kunye ne-absorption, i-fluoropolymers eqhutywe ngokunyibilika njenge-PFA ibonisa iipropati ezingcono zokuthintelwa kune-PTFE.
Vacuum Ukumelana
Ukuchaswa kwe-vacuum kuyadingeka kuba, kwiinkqubo ezivaliweyo zohlobo olusetyenziswa kakhulu ekuqhutyweni kweekhemikhali, ukuhla kweqondo lokushisa kudala i-vacuum kwinkqubo, ngaphandle kokuba sele sele isebenza ngaphantsi koxinzelelo lwe-atmospheric.Xa usebenzisa i-PFA kulula ukufezekisa ukuchasana kwe-vacuum okwaneleyo kwi-lining.Ngokwesiqhelo ilinen ?i-ankile?ukuya eludongeni lwentsimbi ngokusebenzisa ?umsila wehobe?imijelo okanye imijelo kwi
mva.
Nge-PTFE granulate eye yabanda-yakhiwe, kunzima kakhulu ukufezekisa i-anchoring yesandi kwindonga yentsimbi njengoko iziteshi ezinkulu ziya kufuneka ukuze kuvunyelwe i-PTFE powder ukuba ingene kwiigrooves.Ngokuqhelekileyo, ngoko ke, ii-agent ezidibeneyo zisetyenziswa phakathi kwe-PTFE ye-lining kunye nezindlu zentsimbi.Nangona kunjalo, ngenxa yeempawu ezichasene ne-adhesive ye-fluoropolymers kunye nokunyanzeliswa kwe-thermal kwi-agency bonding, i-PTFE ibonisa kuphela ukuchasana kwe-vacuum encinci.
Ulawulo loMgangatho luthintela iiNgcali kunye neVoids
Nge-PTFE kunye ne-PFA linings, amandla e-dielectric alinganiswa ukuze kuchongwe iimpazamo.Le ndlela ikhomba ngokuthembekileyo iintanda kunye ne-voids ehamba yonke indlela kwizinto eziphathekayo kodwa, ngenxa ye-resistiveivity ephezulu eyaziwayo ye-fluoropolymers, ayibonisi naziphi na iimpazamo eziqala nge-1,5 mm okanye ngaphezulu ngaphantsi komhlaba (umzobo 5) .
Ngesi sizathu iimvavanyo ezongezelelweyo kusetyenziswa iindlela ze-ultrasonic nazo zinokusetyenziswa.Olu vavanyo lulinganisa umgama ukusuka kumphezulu we-lining ukuya kwindlu yentsimbi.Nangona kunjalo, ayithembeki ngenxa yokuba ayiboneleli ubukhulu becala lokwenyani xa i-void okanye i-porosity ikhona.Ukongeza, le ndlela ayinakwenzeka ukuba isetyenziswe kwiindawo ezincinci okanye iimilo ezincinci ezintsonkothileyo ezinee-undercuts kunye ne-tight radii.
Enye indlela yokujonga iziphene zomphezulu ezifana neentanda kunye ne-voids yile ibizwa ngokuba yi-?Met-L-Check?indlela yokudayi yokungena.Kodwa le ndlela iphelela ekuboneni iziphene ezingaphezulu kuphela.
Ulwakhiwo lweMichiza
I-PFA, eguquguqukayo, inokujongwa ngokuthembekileyo.Ukuqhekeka kunye ne-voids phantsi komhlaba kungenziwa kubonakale ngemithombo yokukhanya efanelekileyo.Iindawo ekungelula ukufikeleleka kuzo kwilining zinokujongwa kusetyenziswa izibane zokukhanya ezibandayo kunye nezikhokelo zokukhanya zefiber eziguquguqukayo.
Iindleko zokuthelekisa iiLinings
Ngokwamaxabiso ezinto ezikrwada, iPFA ixabisa ngokuphindwe kathathu njenge-PTFE.
Nangona kunjalo, oku kungalunganga kunokuthi kubuyekezwe okanye kuncitshiswe kakhulu, njengomsebenzi wezinto ezifana nokumila okuza kufakwa umgca, ubungakanani bayo, inani lee-workpieces eziza kufakwa kunye nendlela yokucubungula yamkelwe.Oku kunokwenzeka ngenxa yokuba iPFA ayifuni ukulungiswa kwenkqubo yezandla okanye ukugqitywa komatshini kunye nelahleko yezinto eziphathekayo.
Ukusetyenziswa kwePFA yokwalathisa iinxalenye ezinkulu kakhulu akukhuthazwa, kuba iindleko eziphezulu zemathiriyeli ziyakwenza ukuba inxalenye ibize kakhulu.Enye ingongoma ekufuneka ikhunjulwe ziindleko zezixhobo, ezingahlawulwanga
xa kuphela amanani amancinci eenxalenye aza kufolwa.Ngaphezu koko, kukho imida esebenzayo kubunzima bezinto ezitofelweyo ezikwazi ukuphatha oomatshini bokubumba.
Izigqibo
Ngaphezulu kweminyaka engama-20 yamava kunye ne-linings yeendawo ezahlukeneyo, umzekelo, i-valve kunye nezindlu zempompo, zibonise ukuba i-PFA ineenzuzo ezininzi xa ukuxhathisa okuphezulu kwe-thermal kunye neekhemikhali zezona mfuno ziphambili.
Ubungqingqwa obuchanekileyo kunye nodonga olunokuthi luphunyezwe ngePFA luluncedo olukhulu, ngakumbi xa usebenza namajelo eendaba anotyekelo oluqinileyo lokusasaza.
Amava asebenzayo nawo abonise ukuba iPFA inika iipropathi ezingcono zesithintelo kune-PTFE.
Abavelisi be-Bromine babika, umzekelo, ukuba ubunzulu bokungena kwe-bromine kwi-PFA malunga nesinye kwisithathu esingaphantsi kwe-PTFE, xa iimeko zokusebenza ezifana nexesha, ubushushu kunye noxinzelelo zifana.
I-PTFE, kwelinye icala, isasetyenziswa ngokubanzi kumalungu eevalvu zekhemikhali kunye nezinye izixhobo zokusetyenzwa kweekhemikhali apho kufuneka ukuxhathisa ukudinwa.
Imizekelo eqhelekileyo yezo zicelo ziyimibhobho, kunye ne-diaphragms kwiivalvu kunye neepompo.
Kwiindandatho zokuhlala, iiplagi, izitywina kunye neendawo ezifanayo, i-PTFE yinto efanelekileyo kunye neyoqoqosho.
Indlela yakutsha nje yeengxenye ezinje kukusebenzisa i-PTFE elungisiweyo, njengoko uzinzo lwe-dimensional nokuqina kwayo kungaphezulu kwezo ze-PTFE ezisemgangathweni.
iithegi:PTFE,PFA,PTFE vs PFA
Ixesha lokuposa: Apr-01-2017