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 ndi mfundo: 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 zokhazikitsa 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 mdera lililonse ndi chiŵerengero cha zopereka; bwerezani mpaka chiwerengero ≥1 (malire achitetezo 1.1-1.2 akulimbikitsidwa).

Nkhaniyi ikufotokoza njira zowongolera crystallinity wa PTFE ❖ kuyanika pa Teflon mkulu-kutentha nsalu. Kuwongolera kwa kuziziritsa 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 lotetezera 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: kungagwiritsidwe ntchito ngati khushoni yopanda ndodo pamalamba 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 mpweya wotentha 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 komanso kuyenda kwamkati, zomwe zimapangitsa kuti kachulukidwe kawongoleredwe kamene kamachepa kuchokera pamwamba kupita mkati.

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 resin. Kubalalika 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 amphamvu filimu.

Nkhaniyi ikufotokoza momwe angagwirizanitsire kutentha ndi theka la moyo wa peroxide crosslinking agents (BPO ndi DCP) ndi zenera lakuchiritsa la tepi ya Teflon. Deta yapakati: BPO - 1-min theka la moyo pa ~ 131 ° C, 1-hr pa ~ 92 ° C, 10-hr pa ~ 72 ° C; DCP - 1-min pa ~ 171°C, 1-hr pa ~135°C, 10-hr pa ~115°C. Zolinga zofananira: zomatira zimafunikira 97-99% kuwoloka = 5-7 theka la miyoyo; kuchiritsa nthawi = 5-7 × theka la moyo pa kutentha kwa chandamale. Kubwerera kuwerengera kutentha kuchokera ku nthawi yopanga mzere wokhalamo kapena kuwerengera nthawi yochokera ku kutentha kovomerezeka.

Nkhaniyi ikukhudza mmene mzere liwiro osiyanasiyana PTFE mkulu-kutentha nsalu impregnation kupanga mzere. Liwiro lofananira: 2-15 m / min, ntchito yokhazikika 3-8 m / min, nsalu zoonda / mizere yothamanga kwambiri mpaka 10-15 m / min. Zoletsa kulowetsedwa kwa impregnation: nsalu iyenera kukhala yodzaza ndi PTFE emulsion mu fiber mtolo wamkati - kuthamanga kwambiri kumayambitsa kusakwanira kwa impregnation, utomoni njala ndi ulusi wouma; emulsion viscosity, zolimba ndende, nsalu yokhotakhota kachulukidwe zonse zimachepetsa kuchuluka kwa malowedwe, zomwe zimafuna kuthamanga pang'onopang'ono kwa nsalu zokhuthala / zowuma. Kudutsa kwa zokutira: ma pass angapo (2-6+) ofunikira pakuyala kopanda chilema; woyamba kupita pang'onopang'ono kwa anangula, wotsatira amadutsa akhoza kuchulukitsidwa pang'ono.

Nkhaniyi ikufanizira kusiyana pakati pa kutentha kwa infrared radiation ndi kutentha kwa mpweya wotentha pamapangidwe ophatikizika ofanana a silicone zomatira wosanjikiza. Njira zosinthira kutentha: mpweya wotentha ndi convection-conduction, wodekha komanso wopita patsogolo, umapanga kutentha pang'ono; IR ndi mayamwidwe a radiation ndi mayamwidwe apamwamba kwambiri (mamicrometer mpaka mamilimita) kumapanga kutsetsereka kotsetsereka kuchokera kumtunda kupita mkati. Zotsatira pa kugawa kachulukidwe ka crosslink: mpweya wotentha umalola kuti magawo amkati ndi akunja alowe m'malo otentha kwambiri nthawi imodzi, kutulutsa kachulukidwe kofanana ndi makulidwe; IR imayambitsa kusanjikiza kwapamwamba kuti kuchiritse khungu lowundana nthawi yomweyo lomwe limalepheretsa kutentha, zomwe zimapangitsa kuti kachulukidwe kakang'ono ka crosslink kuchepe kuchokera pamwamba mkati.

Nkhaniyi ikufotokoza za silika komanso mawonekedwe ogwiritsira ntchito nsalu zapamwamba za silika. Mafotokozedwe a silika: chizindikiro chachikulu ndi SiO₂ ≥96% (muyezo 96-98%, masukulu apamwamba> 99% kudzera pa leaching acid ndi sintering, kuyandikira quartz fiber). Kupanga: Nsalu ya magalasi a E-magalasi imalowa m'madzi otentha a asidi kuti asungunuke zinthu zomwe sizili silika (boron oxide, sodium oxide), ndikupanga mafupa amphamvu kwambiri a silika, kenako amasungunula kuti apangike. Ubwino waukulu: ntchito yopitilira 900 ° C mumlengalenga wotulutsa okosijeni, kwakanthawi kochepa kuposa 1200 ° C, kufewetsa pafupi ndi 1700 ° C; kukhazikika kwamankhwala motsutsana ndi ma acid / alkali ambiri kupatula HF ndi asidi wotentha wa phosphoric; otsika dielectric mosasintha ndi khola kutchinjiriza pa kutentha kwambiri.

Nkhaniyi ikufotokoza mawonekedwe a microstructural a nsalu ya Teflon yotentha kwambiri. Chigoba cha gawo lapansi: kapangidwe ka ulusi wagalasi woluka momveka bwino/zoluka zolukanalukana zolimba kwambiri (zotupa zazing'ono zazing'ono mkati mwa mitolo ya ulusi ndi pa warp-weft node) zopatsa mpata kutengera kwa PTFE. Kuyika kapangidwe kazinthu: kuyika kwathunthu kwa encapsulation kupanga 'konkriti yolimba' komwe ulusi wagalasi ukulimbitsa gawo, PTFE ndi masanjidwe opitilira; pamwamba nodular microstructure wa tinatake tozungulira (tinthu ting'onoting'ono) cholumikizidwa ndi fibrils zabwino anapanga pa sintering; mosalekeza wandiweyani wosanjikiza khungu (angapo mpaka makumi a ma microns wokhuthala) wa PTFE koyera ngati chotchinga chachikulu cha kusanjika kwa mankhwala, katundu wopanda ndodo, ndi kutchinjiriza magetsi.