Nkhaniyi ikukhudza ntchito PTFE mkulu-kutentha nsalu mu carbon CHIKWANGWANI lathyathyathya gulu mankhwala. Kumangirira: kuyikidwa pakati pa nkhungu ndi prepregs kuteteza epoxy utomoni adhesion, kuthandizira kugwetsa kosavuta; kumangidwa pakati pa mapanelo owonda angapo kuti apewe kumamatira. Kumangirira thumba la vacuum: filimu yotulutsidwanso pakati pa prepreg ndi nsalu yopumira, kulola kuti mpweya / utomoni udutse ndikupangitsa kuti zisavute zitachiritsidwa; mbali zojambulidwa zimasamutsira mawonekedwe abwino a pamwamba kuti apititse patsogolo kukhwimitsa, kuchotsa mchenga. Kupanga kosalekeza: malamba osamata osamata amanyamula zodziwikiratu kudzera m'malo otentha / kukanikiza; khushoni wosanjikiza amagawa kukakamiza mofananamo kuchepetsa kulowera komweko.

Nkhaniyi ikuyang'ana kuthekera kwa chithandizo chamoto pakusintha kwa PTFE ndikuyerekeza zotsatira ndi chithandizo cha corona ndi plasma. Kuthekera: lawi akhoza kusintha PTFE koma kawirikawiri ntchito m'mafakitale - chitetezo ngozi (PTFE decomposes kutulutsa poizoni HF ndi perfluoroisobutylene); ntchito zochepa (mphamvu zapamtunda zokha 30-35 mN/m, zimapanga malire ofooka). Njira zogwirira ntchito: lawi lamoto - mpweya wotentha kwambiri (> 1000 ° C), kuwotcha pang'ono, magulu ochepa a okosijeni; corona - kutulutsa kwamphamvu kwambiri kumatulutsa ozoni / okosijeni yogwira, okosijeni pang'ono, kachulukidwe kakang'ono ka mphamvu sikungathe kuswa zomangira za CF; plasma - tinthu tambiri tambiri / ma elekitironi / ma radicals aulere amadula mwachindunji zomangira za CF ndi magulu omezanitsa polar (hydroxyl, carboxyl, amino).

Nkhaniyi ikufotokoza momwe angagwirizanitsire liwiro la mzere wa makina okutira ndi kutalika kwa uvuni kuti zitsimikizire kuti zomatira za organosilicone zikufika pa digiri yochiritsa ya tepi yotentha kwambiri ya PTFE. Mfundo yofananira yapakati: nthawi yonse yokhala t_total = kutalika kwa uvuni L ÷ liwiro la mzere v kuyenera kukhala kosachepera nthawi yochizira. Pezani machiritso kudzera ku DSC kapena kuyezetsa zomatira zomwe zimakhazikitsa ubale wa 'kutentha - nthawi yocheperako'. Mtundu wofananira wochiritsa: gawani uvuni m'magawo, werengerani ti=Li/v ndi tcure(Ti), onetsetsani ∑(ti/tcure(Ti)) ≥1. Njira zowerengera: ikani madera otentha ndi kutalika kwa Li ndi kutentha kwa Ti; khazikitsani liwiro la mzere v, kuwerengera nthawi yokhala ndi gawo lililonse ndi chiŵerengero cha zopereka; bwerezani mpaka ≥1 (malire achitetezo 1.1-1.2 akulimbikitsidwa).

Nkhaniyi ikukhudzana ndi ntchito za PTFE muzotchingira zotenthetsera zama injini a missile. Njira zinayi: Endothermic decomposition — PTFE depolymerizes at ~400°C to tetrafluoroethylene (highly endothermic, ~3,000°C kuyaka gasi exposure), kuyamwa kutentha kwakukulu ndi kutulutsa mphamvu zotentha kuchokera pamwamba pa khoma. Transpiration kuzirala ndi mpweya filimu kutchinjiriza - kuwola mpweya (tetrafluoroethylene) amalowa kunja kudzera yaying'ono pores, kuchotsa pamwamba kutentha; filimu yothamanga ya gasi imalekanitsa mpweya woyaka kwambiri kuchokera pakhoma, kuchepetsa kutentha kwapafupi ndi khoma ndi> 50%; Kanema wa gasi amasintha liwiro / kutentha kwa malire, kuchepetsa kukokoloka kwa tinthu.

Nkhaniyi ikufotokoza zotsatira za kuyatsa kwa gamma-ray pamapangidwe a PTFE ndi katundu. Kusintha kwa mankhwala: kuwala kwa gamma kumathyola maunyolo akuluakulu a CC ndi maunyolo a CF mbali (G-mtengo 3.0-3.5), kuchititsa kugwedezeka kwakukulu ndi kulemera kwakukulu kwa maselo; mu okosijeni, ma radicals aulere amapanga ma peroxy radicals oyambitsa ma acyl fluoride ndi magulu omaliza a carboxylic acid (hydrolyzing to HF). Kusintha kwa mawonekedwe a condensed: crystallinity imakwera poyambilira (mlingo wochepa, unyolo waufupi umasinthanso) kenako umagwa (mlingo wapamwamba, zolakwika zimasokoneza makhiristo); Chidutswa cha makristalo a lamellar kukhala ma crystallites ang'onoang'ono omwe amasowa nthawi yayitali. Kuwonongeka kwa katundu: kutalika kwa nthawi yopuma kumatsika kuchoka pa 0.1 kGy mumlengalenga, kutaya> 90% pa ~ 1kGy - zinthu zimakhala zolimba komanso zolimba; malo osungunuka amatsika kuchoka pa 327 ° C kufika pansi pa 310 ° C; magulu a polar amakweza pang'ono kutayika kwa dielectric / kutayika; kusintha kwa pamwamba kuchokera ku zoyera kupita ku imvi / zakuda ndi kutayika kwa gloss.

Nkhaniyi ikufotokoza njira zowongolera crystallinity wa PTFE ❖ kuyanika pa Teflon mkulu-kutentha nsalu. Kuziziritsa kozizira kumakhala kolunjika komanso kothandiza: Kuziziritsa mwachangu (kuzimitsa) kudzera pa makatani a mpweya wozizira, zogudubuza zoziziritsa kuziziritsa kapena matanki amadzi - unyolo wa mamolekyu amaundana asanauzidwe, kupanga tinthu tating'ono tating'ono topanda ungwiro; zokutira ndi zofewa, zolimba ndi magwiridwe antchito osamata, kuchepa pang'ono kuuma / kukana kuvala. Kuziziritsa pang'onopang'ono (kuzizira) kudzera mu gawo losunga kutentha pa 10-50 ° C / h kapena kuziziritsa m'ng'anjo - maunyolo a molekyulu amakonzedwa mokwanira kukhala ma spherulites akulu athunthu; zokutira zimakhala ndi kuuma kwakukulu, kukana kovala bwino, miyeso yokhazikika, kuchepetsedwa kusinthasintha komanso kuchuluka kwa brittleness.

Nkhaniyi ikufotokoza za kugwiritsa ntchito nsalu za Teflon zotentha kwambiri m'ng'anjo zoyendera mpweya wotentha. Kuthekera: kumagwiritsidwa ntchito ngati khushoni yopanda ndodo pa malamba a mauna kapena thireyi kutentha kwa ng'anjo ≤260 ° C (kuyanika kwa kutentha pang'ono, kuchotsa zomangira, kuchiritsa matope) - kumathandizira kugwetsa ndi kutola bwino. Zoletsedwa kwambiri pa kutentha kwapakati/kutentha (300-950°C) — PTFE imawola kutulutsa poizoni wa HF ndi perfluoroisobutylene, zida zowononga ndikupangitsa chiphe chakupha. Mfundo yachitetezo: ngati kutentha kwa ng'anjo sikudziwika bwino kapena sikungatsimikizidwe pansi pa 260 ° C, musagwiritse ntchito. Zinthu zazikuluzikulu: ntchito yosalekeza -70 ° C mpaka 260 ° C, yochepa 300 ° C; monyanyira sanali ndodo ndi inertness mankhwala; kusungunula bwino kwamagetsi; kukangana kochepa (~ 0.04); fiberglass base imapereka mphamvu zolimba kwambiri.

Nkhaniyi ikufanizira kusiyana pakati pa kutentha kwa ma radiation a infrared ndi njira zochiritsira zotenthetsera pamlengalenga pamapangidwe ophatikizika amitundu yomatira ya silicone. Njira zosinthira kutentha: mpweya wotentha umadalira pa convection-conduction ndi kutentha pang'ono kutentha, kusiyana kochepa mkati / kunja kwa kutentha; IR ili ndi kuzama kochepa kolowera komwe kumayamwa mwamphamvu pamwamba (makumi mpaka mazana a ma micrometer) kumapanga kutsetsereka kotsetsereka kuchokera kumtunda kupita mkati. Zotsatira zakufanana kwa crosslink: mpweya wotentha umathandizira kuchiritsa kolumikizana mkati ndi kunja ndi kachulukidwe kofanana; IR imapangitsa kuti pamwamba pakhale 'filimu yapakhungu' yowundana yomwe imalepheretsa kutentha ndi kayendedwe ka mkati, zomwe zimapangitsa kuti kachulukidwe kawo kawongoleredwe kutsika kuchokera pamwamba kupita mkati.

Nkhaniyi ikukhudzana ndi liwiro la mzere wa mzere wopanga nsalu wa Teflon wotentha kwambiri. Kuthamanga kwapakati: mankhwala ochiritsira ochiritsira (0.08-0.30mm) pa 0.5-3 m / min, okhazikika pa 1-3 m / min; zinthu zokhuthala / zolowetsedwa wambiri (≥0.4mm) pa 0.3-1 m / min; mizere yogwira ntchito kwambiri yokhala ndi uvuni wautali imatha kufika 3-6 m / min koma zida zofunikila. Zolepheretsa ndondomeko: kuyanika ndi sintering kumafuna nthawi yokhalamo (PTFE imafuna 1-3 min pa 380-400 ° C; osakwanira amachititsa kusamata bwino / kusweka); Liwiro limatsimikiziridwa ndi nthawi yocheperako yowumitsa / sintering pansi pautali wokhazikika wa uvuni. Zopinga zakuthupi: zolimba kwambiri / mamasukidwe akayendedwe dispersions amalowa pang'onopang'ono; nsalu zokhuthala/zowuma zimatenga madzi ndi kusamutsa kutentha pang'onopang'ono; Nsalu zazikulu zomwe zimakonda kusiyanasiyana kwamitundu yapakati zomwe zimafuna kuchepetsa liwiro. Zida ndi malonda abwino: Mavuni aatali amitundu yambiri amalola kuthamanga kwambiri.

Nkhaniyi chimakwirira kusiyana PTFE emulsions opangidwa ndi kuyimitsidwa polymerization vs kupezeka polymerization. Kufotokozera: kuyimitsidwa polymerization sangathe mwachindunji kubala PTFE emulsion; weniweni PTFE emulsion amachokera kokha kupezeka polymerization. 'Suspension-Method emulsion' kwenikweni ndi kuyimitsidwa kwamadzi kwa ma micropowder oyimitsidwa a utomoni wapolymerized. Kubalalitsidwa polymerization (emulsion pulayimale): ozungulira particles (0.1-0.3μm, yopapatiza kugawa), okhazikika ndi perfluorinated surfactants, mkulu kwambiri maselo kulemera (> 94% crystallinity), fibrillation wamphamvu, amafuna 380 ° C sintering kupanga mosalekeza lolimba filimu.