Tsawon shekaru masu yawa masanan fluoropolymers sun taka muhimmiyar rawa a cikin sinadarai da masana'antu makamantan su don kare tsire-tsire da kayan aiki daga harin sinadarai ta hanyar watsa labarai masu yawa.Wannan shi ne saboda suna ba da mafi kyawun juriya na sinadarai da kwanciyar hankali fiye da sauran robobi ko kayan elastomeric. Shekaru da yawa masanan fluoropolymers sun taka muhimmiyar rawa a cikin sinadarai da masana'antu makamantan su don kare tsire-tsire da kayan aiki daga harin sinadarai ta hanyar faɗuwar kewayon m. kafofin watsa labarai.Wannan saboda suna ba da ingantaccen juriyar sinadarai da kwanciyar hankali fiye da sauran robobi ko kayan elastomeric.
Bayan ci gaban PTFE, ƙaddamar da ethylene-propylene mai narkewa mai narkewa (FEP) a cikin 1960 ya buɗe sabbin wuraren aikace-aikacen gaba ɗaya.PFA, wani perfluoro-alkoxy polymer wanda ya kasance a cikin nasarar amfani da shekaru 20 a matsayin kayan rufi, yanzu shine magajin thermoplastic ga PTFE, tare da daidaitattun thermal da juriya na sinadarai da kaddarorin da suka fi dacewa dangane da aiwatarwa, translucency, juriya da ƙarfin injin .
A cikin masana'antar sinadarai, duka fluoropolymers - PTFE da PFA - ana amfani da su galibi a cikin nau'ikan rufi.Don siffofi masu sauƙi, irin su bututu, lanƙwasa, T-yanki ko raguwar haɗin gwiwa, ana amfani da PTFE gabaɗaya;Ana amfani da shi ta hanyar extrusion na manna, rago extrusion ko tef-iska.A cikin waɗannan matakai ana yin pre-forma na PTFE;Wannan sai a juye a saka shi a cikin kayan aikin karfe.Amfani da PTFE don rufin sassa na ƙarfe na siffa mai rikitarwa, kamar bawuloli da famfo, ya fi wahala.Isostatic gyare-gyaren shine hanyar da aka fi so.A cikin wannan foda na PTFE an cika shi a cikin sararin da aka samar tsakanin karfen aikin karfe da jakar roba wadda aka yi ta musamman don dacewa da siffar wurin da za a yi layi.An riga an danne foda, sannan an danna sanyi a cikin siffar da ake so.A ƙarshe, an cire jakar robar kuma ana juyar da sashin layi a cikin tanda sama da 360?C (680?F).
PFA, wani abu mai ma'aunin zafi da sanyio tare da ma'anar narkewa mai kyau, ana iya sarrafa shi ta hanyar canja wuri ko gyare-gyaren allura.Ana narkar da granulate a cikin tukunyar narke ko a cikin mai cirewa sannan kuma a tilasta shi cikin kayan aiki mai zafi ta hanyar latsawa na hydraulic.
Wannan hanyar tana ba da damar samun madaidaicin kauri na bango, tare da jure wa?0,5 mm, ko da a m radis kuma a undercuts.A zahiri ba a buƙatar kammala aikin injiniya, sai dai don cire sprue da kuma santsin fuskokin mating na flanges.
Lokacin amfani da gyare-gyaren isostatic, duk da haka, ana buƙatar adadi mai yawa na kammala aikin injiniya - ya danganta da girman rikitarwa na siffar da za a cika - don cimma girman da ake so tare da daidaito.
Matsakaicin kauri na bango na iya bambanta da yawa, musamman ma idan aka kwatanta da sifofi masu rikitarwa kamar gidaje na bawul.
Shayewa da Ratsawa
Ba kamar karafa ba, robobi da elastomers suna ɗaukar nau'ikan kafofin watsa labaru daban-daban waɗanda suke haɗuwa da su.Wannan shi ne sau da yawa lamarin da kwayoyin halitta.Ana iya biye da sha ta hanyar shiga cikin bangon bango.Ko da yake ba a cika ganin wannan tare da fluoropolymers ba, ana iya magance shi ta hanyar karuwar kauri na bango ko kuma ta hanyar shigar da na'urori don ƙare sararin samaniya tsakanin rufin fluoropolymer da bangon karfe.An nuna a fili cewa game da shaye-shaye da sha, narke-aiki na fluoropolymers irin su PFA suna nuna mafi kyawun kaddarorin shinge fiye da PTFE.
Matsala Resistance
Ana buƙatar juriya na vacuum saboda, a rufaffiyar tsarin nau'in nau'in da ake amfani da su sosai wajen sarrafa sinadarai, raguwar zafin jiki yana haifar da vacuum a cikin tsarin, sai dai idan ya riga ya yi aiki ƙasa da yanayin yanayi.Lokacin amfani da PFA abu ne mai sauƙi don cimma isasshen juriya ga rufin.Yawancin lokaci rufin ya kasance?zuwa bangon karfe ta hanyar ?wutsiya-kurciya?tsagi ko tashoshi a cikin
daga baya.
Tare da PTFE granulate da aka yi sanyi, yana da wuya a cimma sautin sauti na rufi a cikin bangon karfe kamar yadda za a buƙaci manyan tashoshi don ba da damar foda na PTFE ya shiga cikin ramuka.Mafi yawanci, saboda haka, ana amfani da abubuwan haɗin gwiwa tsakanin rufin PTFE da gidajen ƙarfe.Duk da haka, saboda halayen anti-adhesive na fluoropolymers da iyakataccen juriya na thermal na abubuwan haɗin gwiwa, PTFE yana nuna ƙarancin juriya kawai.
Kulawa da inganci yana hana kararraki da ɓarna
Tare da rufin PTFE da PFA, ana auna ƙarfin dielectric don gano kuskure.Wannan hanyar ta dogara da tsinkaya tsatsauran ra'ayi da ɓarna waɗanda ke bi ta cikin kayan amma, saboda sanannen babban juriya na fluoropolymers, baya nuna wani kuskure wanda ya fara 1,5 mm ko fiye a ƙarƙashin saman (fig. 5). .
Don haka ana iya amfani da ƙarin gwaje-gwaje ta amfani da hanyoyin ultrasonic.Wannan gwajin yana auna nisa daga saman rufin zuwa gidan ƙarfe.Duk da haka, ba abin dogaro ba ne saboda baya samar da kauri na gaskiya lokacin da babu komai ko porosity ya kasance.Bugu da ƙari, wannan hanya ba ta da amfani don yin aiki a kan ƙananan sassa ko ƙananan sifofi masu rikitarwa tare da raguwa da radius mai ma'ana.
Wata hanya don bincika lahani na sama kamar tsagewa da ɓoyayyiya tana tare da abin da ake kira ?Met-L-Check?hanyar rini shiga ciki.Amma wannan hanya ta iyakance ga gano lahanin saman kawai.
Tsarin Sinadarai
PFA, wanda yake translucent, za a iya dogara da shi ana bincika shi ta gani.Ana iya ganin fashe da ɓoyayyen ƙasa tare da hanyoyin haske masu dacewa.Wuraren da ke da wuya a cikin rufin ba za a iya bincika ta amfani da fitilun haske mai sanyi da jagororin hasken fiber masu sassauƙa ba.
Kwatancen Kuɗi don Linings
Dangane da farashin albarkatun ƙasa, PFA yana kusan ninki uku fiye da PTFE.
Wannan rashin lahani na iya, duk da haka, ana iya ramawa ko ragewa sosai, a matsayin aiki na abubuwa kamar siffar da za a yi layi, girmansa, adadin kayan aikin da za a yi layi da hanyar sarrafawa.Wannan yana yiwuwa saboda PFA baya buƙatar shirye-shiryen aikin hannu ko gama aikin injin tare da asarar kayan daidai.
Ba a ba da shawarar yin amfani da PFA don rufe manyan sassa ba, saboda babban farashin kayan zai sa ɓangaren yayi tsada.Wani batu da ya kamata a tuna shi ne farashin kayan aiki, waɗanda ba a kashe su ba
lokacin da ƙananan lambobi ne kawai za a yi layi.Bugu da ƙari, akwai iyakoki masu amfani ga nauyin kayan allura waɗanda injunan gyare-gyare ke iya sarrafa su.
Ƙarshe
Fiye da shekaru 20 na gwaninta tare da linings don sassa daban-daban, misali bawul da gidaje famfo, sun nuna cewa PFA yana da fa'idodi masu yawa lokacin da babban zafin jiki da juriya na sinadarai sune manyan buƙatu.
Daidaitacce kuma har ma da kauri na bango wanda za'a iya samu tare da PFA shine babban fa'ida, musamman lokacin aiki tare da kafofin watsa labaru waɗanda ke da ƙaƙƙarfan hali don yaduwa.
Kwarewar aiki ta kuma nuna cewa PFA yana ba da mafi kyawun kaddarorin shinge fiye da PTFE.
Masana'antun Bromine sun ba da rahoton, alal misali, cewa zurfin shigar bromine a cikin PFA ya kusan kashi ɗaya bisa uku ƙasa da na PTFE, lokacin da yanayin aiki kamar lokaci, zafin jiki da matsa lamba iri ɗaya ne.
PTFE, a gefe guda, har yanzu ana amfani da shi sosai don abubuwan da ke tattare da bawul ɗin sinadarai da sauran kayan sarrafa sinadarai inda ake buƙatar juriyar gajiya.
Misalai na yau da kullun na irin waɗannan aikace-aikacen sune bellows, da diaphragms a cikin bawuloli da famfo.
Don zoben wurin zama, matosai, hatimi da makamantansu, PTFE abu ne mai dacewa da tattalin arziki.
Yanayin kwanan nan don sassa irin waɗannan shine amfani da PTFE da aka gyara, saboda girman girman girmansa da taurinsa sun fi na daidaitattun PTFE.
Tags: PTFE, PFA, PTFE vs PFA
Lokacin aikawa: Afrilu-01-2017