Kuchokera pamalingaliro azinthu zitatu zomwe zimadziwika kuti katundu wa PTFE - kulemera kwa maselo, crystallinity ndi voidage, kutayika kumakhudzidwa makamaka ndi kuthamanga kwa preforming, ndi kulemera kwa maselo ndi crystallinity zonse zimasintha ndi zosiyana siyana za sintering.Chifukwa chake,ndondomeko ya sinteringzinthu zimatenga gawo lalikulu muzinthu zomaliza za zinthu monga kachulukidwe, kuuma, permeability ndi makina.
Kuchokera pamalingaliro azinthu zitatu zomwe zimadziwika kuti katundu wa PTFE - kulemera kwa maselo, crystallinity ndi voidage, kutayika kumakhudzidwa makamaka ndi kuthamanga kwa preforming, ndi kulemera kwa maselo ndi crystallinity zonse zimasintha ndi zosiyana siyana za sintering.Chifukwa chake, mikhalidwe ya sintering imatenga gawo lalikulu pazomaliza zazinthu monga kachulukidwe, kuuma, permeability ndi makina.
Wang ping adapeza kutindondomeko ya PTFEanakhudzidwa ndi kukwera ndi kugwa liwiro, sintering kutentha ndi sintering nthawi.Kukula kwa mankhwalawo, kumachepetsa kuthamanga kwa kukwera ndi kuzizira, ndi nthawi yayitali ya sintering.Kutentha kwa sintering kwa utomoni woyimitsidwa ndikokwera kuposa utomoni wobalalika.Kutentha kwa sintering kwa zinthu zoyera ndizokwera kuposa zazinthu zodzazidwa.Nthawi zambiri, kuchuluka kwa kutentha kumathamanga kwambiri kuposa kuzizira.Mu ng'anjo yotentha yomweyi, zinthu zoyera ndi zodzaza sizingasakanizidwe;Zogulitsa zokhala ndi sintering zosiyanasiyana sizingasakanizidwe.Zogulitsa zamitundu yosiyanasiyana sizingasakanizidwe.Kutenga 3-wosanjikiza kuumbidwa mbale zozungulira ndi awiri a 1 m, makulidwe a 20 mm, awiri wosanjikiza monga koyera ptfe ndi wosanjikiza pakati monga wodzazidwa ptfe chitsanzo, psinjika mphamvu, kupinda mphamvu, kuuma ndi zina makina katundu wa zozungulira laminated mbale opangidwa ndi luso limeneli akhala bwino kwambiri.
Liu xianlan anaphunzira za kupanga ndondomeko makhalidwe, kupanga njira ndi nkhungu kapangidwe makhalidwe a PTFE, kusanthula zolakwika ndi zimene zimayambitsa PTFE mankhwala opangidwa ndi ozizira kukanikiza ndi sintering, ndi kuika patsogolo njira mankhwala.PTFE akhoza kuumbidwa ndi njira zosiyanasiyana preforming, monga akamaumba, extrusion, hayidiroliki akamaumba, kukankhira akamaumba ndi processing yachiwiri, ndiyeno sintered kwa chomaliza product.PTFE akamaumba zambiri zopangidwa inaimitsidwa utomoni.Pamene makulidwe a pepala ndi osachepera 1.5mm, kumwaza utomoni ntchito.Kachitidwe kake kaukadaulo: utomoni - sieve (kuyimitsidwa utomoni pambuyo kusinja, lotayirira, ndi 20 mauna mauna sieve) - press (PTFE ufa Kukweza nkhungu pansi pa kupsyinjika 20 mpaka 35 MPa, atolankhani compaction kupanga) - sintering (mu 370 ~ 380) "C kutentha sintering mu ng'anjo sintering) - zopangidwa zopangidwa (pansi pa free state mkati mwa nkhungu kapena mutatha kuzirala kuti amalize kupanga monga momwe akufunira ndi bolodi, ndodo, machubu, ma gaskets ndi zonyamula katundu, etc.) .Njira ya Hydraulic imatchedwanso kuti Njira yofananira kapena kuumba kwa mphira munjira yake yogwirira ntchito ndi: ikani thumba la mphira mu kufa - lolumikizidwa ndi mpope wamadzi, kudzaza madzi kutukumula thumba la raba mu cylindrical - utomoni wolumikizana wogawana pakati pa thumba ndi kutseka nkhungu yakunja - pitilizani kukulitsa pang'onopang'ono kuthamanga kwa madzi, kudzaza madzi mpaka 12 ~ 13 mpa kukakamiza kusunga 30 min: pambuyo pa madzi - kuponderezedwa, kung'amba, sintering, kuzizira ndiko kugwiritsa ntchito maonekedwe owala ndi oyera.Kankhani amatchedwanso phala extrusion akamaumba, 20 ~ 30 mauna sieve dispersion utomoni ndi organic madzi (monga toluene, mafuta efa, zosungunulira mafuta) osakaniza 1: 5 phala osakaniza, preloading mu wandiweyani khoma yamphamvu billet, kukankhira mu kompresa yamphamvu. , Kutentha, ndi plunger kukankhira akamaumba, pambuyo kuyanika mu 360 ~ 380 ° C kutentha sintering, pambuyo mankhwala ozizira ndi amphamvu Kankhani chubu, ndodo, etc.Extrusion akamaumba akhoza kugawidwa mu mitundu iwiri: wononga extrusion ndi plunger extrusion.The pre-sintered utomoni pambuyo kuphwanya ndi kusefa amawonjezeredwa pa silinda yakuthupi.Kupyolera mu kuzungulira wononga kapena kukankhira kobwerezabwereza kwa plunger, zopangirazo zimatumizidwa ku extruder nthawi yomweyo ya compaction.
Wang ping adaphunzira kupanga zinthu za thovu la PTFE.Polytetrafluoroethylene yoyimitsidwa imagwiritsidwa ntchito ngati zopangira, ndipo ma condensed cyclic onunkhira ma hydrocarbons amasankhidwa ngati pore-forming agent.Pambuyo kusakaniza, preforming mankhwala ndi preformed ndi sintered.Pa gawo loyambirira la sintering, njira yowumitsa imatengedwa kuti ipangitse pore-forming agent kuthawa, ndiyeno resintering stage imalowetsedwa.Zida za thovu zokhala ndi ma dielectric osiyanasiyana zimatha kukonzedwa mosiyanasiyana kuti zikwaniritse zofunikira zosiyanasiyana.
Chen xu et al.adachita mayeso oponderezedwa ndi mayeso a sintering pa PTFE, adakambirana za ubale pakati pa kachulukidwe, mphamvu yopondereza ndi kukakamiza modulus, ndikusanthula mphamvu yakupondereza kwa zitsanzo pansi panjira zosiyanasiyana za sintering, ndikupeza kukakamiza koyenera kuumba ndi njira yopangira sintering.Zotsatirazo zinasonyeza kuti mphamvu ya PTFE inachepa ndi kuwonjezeka kwa kukakamiza, ndipo kuponderezana modulus kumawonjezeka ndi kuwonjezeka kwa kukakamiza.Kuthamanga kowumba kunali 27.5mpa, kutentha kwa sintering kunali 380 C, ndipo nthawi yotsekemera inali 4h.
Pofuna kuthana ndi kuipa koyera ptfe, monga osauka abrasion kukana ndi lalikulu matenthedwe kukulitsa koyefishienti, Raytheon anaphunzira mkuwa wodzazidwa particles mu ptfe, ndi kukodzedwa ntchito kuchuluka kwa ptfe.The ochiritsira ofunda kukanikiza akamaumba a ptfe imadziwika ndi mkombero wautali, kusagwira bwino ntchito, otsika dimensional molondola ndi yosalala, pamene ofunda kukanikiza akamaumba mu phunziro ili ndi njira zochepa ntchito, mkombero waifupi ndi kwambiri bwino makina katundu.
Nthawi yotumiza: Mar-14-2017