Malo osungunuka a crystalline a PTFE ndi 327 ℃, koma utomoni uyenera kukhala pamwamba pa 380 ℃ kuti ukhale wosungunuka.Komanso, PTFE ali kwambiri zosungunulira kukana.Choncho, sangathe kugwiritsa ntchito kusungunula kapena kusungunuka.Nthawi zambiri, kupanga zinthu zake zitha kuchitika ngati chitsulo ndi ceramic processing.Ufawu umayamba kupangidwa, kenako kusungunulidwa ndi makina, kapena kupangidwa ndi extrusion, Isobaric kupanga, kupaka kupanga, ndi kupanga calendering.
Malo osungunuka a crystalline a PTFE ndi 327 ℃, koma utomoni uyenera kukhala pamwamba pa 380 ℃ kuti ukhale wosungunuka.Komanso, PTFE ali kwambiri zosungunulira kukana.Choncho, sangathe kugwiritsa ntchito kusungunula kapena kusungunuka.Nthawi zambiri, kupanga zinthu zake zitha kuchitika ngati chitsulo ndi ceramic processing.Ufawu umayamba kupangidwa, kenako kusungunulidwa ndi makina, kapena kupangidwa ndi extrusion, Isobaric kupanga, kupaka kupanga, ndi kupanga calendering.
Compression Molding
Kupaka compress ndiye kwambiriPTFE akamaumba processingnjira yomwe ikugwiritsidwa ntchito pa PTFE.Njira yopangira ndi njira yomwe zipangizo zina zopangira (ufa, pellets, zipangizo za fibrous, etc.) zimayikidwa mu nkhungu yachitsulo ndikuwumbidwa pa kutentha kwina ndi kupanikizika.Ma polima opangidwa ndi kuponderezedwa amawumbidwa samangokhala ndi kulemera kwake kwa maselo, ndipo pafupifupi mapulasitiki onse amatha kukonzedwa ndikumangirira.Makhalidwe akuluakulu a psinjika akamaumba ndi: mtengo wotsika, zida zosavuta, ndalama zochepa, komanso zosawerengeka ndi kulemera kwa maselo a pulasitiki yokonzedwa;kuipa ndi otsika kupanga dzuwa, mkulu ntchito mwamphamvu, ndi kusakhazikika mankhwala khalidwe.Kulemera kwa ma molekyulu a PTFE ndikokwera kwambiri ndipo fluidity ndi yoyipa kwambiri.Pamene njira zina processing ali mwana, mayiko padziko lonse lapansi makamaka ntchito psinjika akamaumba pokonza PTFE mankhwala.
Njira yeniyeni yopangira ma compression imagawidwa kukhala ① press-sinter-press njira;② njira ya sinter-press;③ mofulumira Kutentha-atolankhani njira;④ akanikizire ndi sinter nthawi imodzi.
Hydroforming
Njira yama hydraulic imatchedwanso njira yofananira ndi njira yofananira, yomwe ndikuwonjezera PTFE utomoni wogawana pakati pa thumba la mphira ndi khoma la nkhungu, ndiyeno kubaya madzi (madzi omwe amagwiritsidwa ntchito nthawi zambiri) mu thumba la mphira, ndi thumba la mphira lomwe limapanga. Kupanikizika kumakulirakulira mpaka khoma la nkhungu ndi kuphatikizika utomoni umakhala njira ya preforms.Njirayi ingagwiritsidwe ntchito popanga manja akuluakulu, akasinja osungira pansi, zipolopolo za hemispherical, mizati ya nsanja, ma slabs akuluakulu, ndi zina zotero, ndipo angagwiritsidwe ntchito popanga tiyi, zigongono, zipangizo zamakono, ndi zina zomwe zimakhala ndi PTFE.Zogulitsa zokhala ndi mawonekedwe ovuta.Ubwino waukulu wa hydroforming ndi mawonekedwe osavuta a zida ndi nkhungu.Pampu yamadzi wamba imalowa m'malo mwa makina osindikizira amphamvu kwambiri.Zogulitsazo zimapanikizidwa mofanana, zimakhala ndi kachulukidwe kogwirizana, zimatha kupanga zigawo zikuluzikulu, zimakhala ndi mawonekedwe ovuta, komanso zomangira zosavuta.
Kukankhira kupanga
Kukankha kumatchedwansophala extrusionkuumba.Utoto wa 20-30 mesh sieved dispersing resin umasakanizidwa ndi zowonjezera organic (toluene, petroleum ether, solvent oil, etc., gawo la utomoni wolemera ndi 1/5) kuti apange phala.Wothiridwapo kale kukhala chozungulira chozungulira chokhuthala chopanda kanthu, kenako ndikuchiyika muzosindikiza, ndikugwiritsa ntchito plunger kupanga potentha.Ikaumitsa, imatenthedwa pa kutentha kwa 360 ~ 380C, ndipo itatha kuzirala, chubu chokankha cholimba, ndodo, ndi zinthu zina zimapezedwa.Zokankhira zimangokhala ndodo zokhala ndi mainchesi 16mm kapena kuchepera komanso mapaipi okhala ndi makulidwe a khoma 3mm kapena kuchepera.
Spiral extrusion akamaumba
The wononga extruder wa PTFE ufa ndi wosiyana ndi extruder ntchito thermoplastics ena.Kumangirira kwa Zengtong thermoplastics ndikupititsa patsogolo zinthuzo pozungulira wononga, ndikuseweranso ngati kuponderezana, kumeta ubweya, ndi kusakaniza., Zinthuzo zimasungunukanso ndi kutentha komwe kumapangidwa ndi mphamvu yowonongeka komanso kutentha kwakunja kwa zinthuzo.Zowononga za PTFE wononga extruder zimangogwira ntchito yotumiza ndikukankhira, kotero kuti zinthuzo zimadutsa pamutu wa chotupa chimodzi chokhala ndi mikwingwirima iwiri, phula lofanana ndi kuya kofanana, kenako ndikulowa kufa kwa sintering, Kuzizira. ndi kuumba ndi kukakamizidwa koperekedwa ndi chipangizo cha backpressure kuti akwaniritse cholinga chopitilira.Pamene processing PTFE ndi limodzi wononga extruder, mavuto aakulu nthawi zambiri amakumana.Chifukwa chokondera cha PTFE ufa ndi chochepa kwambiri, chimayambitsa kutsetsereka panthawi yodyetsa, zomwe zimachepetsa kwambiri mphamvu yotumizira wononga.Kuphatikiza apo, chifukwa cha kukangana ndi kutulutsa kutentha, ufa ukhoza kumamatira ku screw kapena mbiya, zomwe zimapangitsa kudyetsa kukhala kovuta komanso kosakhazikika.
M'zaka zaposachedwa, zomangira zamapasa zakhala zikugwiritsidwanso ntchito pokonza zinthu zamtunduwu wapadera.Mfundo yake yodyetsera ndi yosiyana ndi ya single-screw extruders.Zili ndi zotsatira zabwino zotumizira ndipo zimatha kuthana ndi kutsetsereka kwa ufa wa UHMWPE mu screw.Kupititsa patsogolo mphamvu ya screw feeding.Pakati pawo, kauntala-azungulira amapasa screw extruder ali bwino kusanganikirana ndi zotsatira homogenization kuposa wozungulira amapasa-screw extruder, koma chifukwa cha mphamvu yake yaikulu kulekana, kumeta ubweya zotsatira pa wononga kusiyana ndi wamkulu, kuchititsa zinthu kutenthedwa. ndi extrude.Kulemera kwa mamolekyulu azinthu zotulutsa kumatha kuchepetsedwa ndi 40%.Ngati bwalo lapangidwa kukhala lalikulu ndipo zomangira sizikuphatikizidwa, zinthuzo zimamatira kuzitsulo zotentha kwambiri.Komabe, kugwiritsa ntchito ma co-rotating twin-screw extruders alibe mavuto omwe ali pamwambapa.Kumeta ubweya wa zinthu mu extruder ndi yaing'ono, ndi kutentha chofunika kwa plasticization zonse kuchokera kunja Kutentha gwero, kotero izo zikhoza kuyendetsedwa molondola kuti kutenthedwa kuwonongeka kwa zinthu pa ndondomeko extrusion akhoza kuchepetsedwa, ndi panthawi imodzimodziyo kusunga Kuyenda kwa zipangizo mumutu wa makina kumakhala kozolowereka komanso kosasunthika, ndipo mapangidwe a kukula kwa gawo la mutu wa makina ayenera kusinthidwa ndi kuchuluka kwa zinthu zomwe zimaperekedwa ndi screw.Kuthamanga kwa wononga sikungakhale kofulumira, nthawi zambiri kuzungulira 10 pamphindi.Pofuna kupewa zinthu mwadzidzidzi kumamatira pamwamba zitsulo, kutentha kwa extrusion kuyenera kuyendetsedwa mosamalitsa.
Plunger extrusion akamaumba
Plunger extrusion akamaumba processing mapulasitiki ndi njira yakale mu processing pulasitiki.Kuyambira pomwe zida zapulasitiki zidayamba, anthu ayamba kugwiritsa ntchito njira iyi pokonza mapulasitiki.Pokonza PTFE ndi plunger extruder, utomoni wochuluka umakanizidwa mu nkhungu, plunger imabwezeretsedwanso, ndipo imakanikizidwa kukhala preform.Mwanjira iyi, ma preforms angapo amapangidwa mukufa.Chifukwa cha kukangana pakati pa PTFE utomoni ndi kukangana pakati pa PTFE utomoni ndi kufa khoma, kukana kwaiye.Pa nthawi yomweyi, kukula kwa voliyumu ya preform pamene sintered mu kufa kumapangitsanso kukana, kotero kuti ndi preform ya gawo limodzi.Sintering ndi kuziziritsa pansi pa mavuto kupanga mosalekeza lonse.Ubwino wa njirayi ndi: palibe kukameta ubweya panthawi yowumba, kulemera kwa maselo kumachepetsedwa, ubwino wa mankhwalawo ndi wabwino, ndipo suli wocheperapo ndi kulemera kwake kwa maselo, ndipo amatha kukonza ma diameter akuluakulu ndi m'mimba mwake pazipita 500mm ndi khoma makulidwe 3mm okha.Chitoliro.Komabe, chifukwa cha malo ang'onoang'ono olumikizana pakati pa zopangira ndi gawo lotenthetsera panthawi yotumiza, kutentha kwachangu kumakhala kochepa, komwe kumachepetsa kuthamanga kwa extrusion yake.
Nthawi yotumiza: Jun-14-2020