Lesi sihloko sihlanganisa ukusetshenziswa kwendwangu ye-Teflon high-temperature (indwangu ye-fiberglass eboshwe nge-PTFE) emkhakheni we-aerospace. Izindawo zesicelo esibalulekile: Ukukhiqizwa kwezinto ezihlanganisiwe - indwangu yokukhulula / ifilimu ekubunjweni kwe-autoclave, izendlalelo zokuhlukanisa, amabhande okuthutha asezingeni eliphezulu okukhiqizwa kwangaphambili; Injini kanye nokuvikelwa kokushisa okushisayo okuphezulu - izingubo zokuvala ezishisayo, i-firewall cladding, ukuxhumana okuguquguqukayo okunokushisa okuphezulu; Ukufakwa kukagesi nokuvikela izintambo zezintambo - ukusonga ikhebula emagumbini enjini kanye nezindawo zokumisa amagiya; Ingaphakathi lendiza kanye nokuvikela umlilo — amakhethini omlilo/izithiyo zentuthu ezihlangabezana nezindinganiso ze-FST, ukumbozwa kwengubo yokuvala okushisayo/okuzwakalayo; Izinhlelo zokusebenza ze-Space kanye ne-aerospace - ama-multi-layer insulation (MLI) ama-assemblies, ama-anti-cold-weld lubrication liner wezindlela zokuthunyelwa kwamaphaneli elanga namahinge e-antenna, indwangu yokulawula ukushisa.

Lesi sihloko sichaza ukuthi i-PTFE inamathela kanjani ku-fiberglass fabric substrate engutsheni ye-Teflon enezinga eliphezulu lokushisa. Ukuhlanganiswa kwamakhemikhali okuqondile akunakwenzeka ngenxa yamandla angaphezulu aphansi we-PTFE. Ukubophezela kufinyelelwa: Ukuxhumanisa ngomshini (ukubopha ngokomzimba) - I-emulsion ye-PTFE ingena ezikhaleni ze-fiber futhi ibambe izinyanda ze-fiber ngemva kokucwiliswa; I-Silane coupling agent pretreatment - yenza ibhuloho lamangqamuzana phakathi kwemicu yengilazi ye-inorganic kanye ne-organic primer; Isendlalelo se-Chemical primer transition layer — kusetshenziswa i-PAI, i-PPS, i-PES noma i-PEEK resins ene-PTFE micropowder, esetshenziswa ngemva kokuhlanganisa ukwelashwa ukuze kwakheke ungqimba oluqinile loguquko; I-hot-melt adhesive adhesive film lamination — Amafilimu e-FEP noma e-PFA (iphuzu elincibilikayo elingu-260-310°C) ahlanganisa amafilimu e-PTFE enziwe ngaphambilini endwangu; Isakhiwo segrediyenti ngemijikelezo yokufakwa okuningi kanye ne-sintering — nciphisa iphasi yokuqala nge-binder/coupling ingena ijule kumafayibha, ilandelwe ukufakwa okumsulwa kwe-PTFE, idala ukuhleleka kwegradient kusuka ku-fiberglass kuya ku-PTFE emsulwa.

Lesi sihloko sikhuluma ngendlela idizayini yesakhiwo esine-microporous ye-Teflon ephefumulayo (PTFE) yetheyiphu yokushisa ephezulu ebhalansisa ukungeneka komoya nge-insulation kanye nezakhiwo ezinganamathi. Ukungqubuzana okuyinhloko: ukungena komoya kudinga izimbotshana ezivulekile, kuyilapho ukwahlukanisa kudinga ukuminyana futhi okunganamathi kudinga izindawo ezibushelelezi. Amasu okuklama okulinganiselayo: lawula isilinganiso se-pore ububanzi (0.1-2μm, ngokufanelekile <0.5μm) ukuvimbela ukungena okuncibilika nokugcina i-voltage yokuphuka; lawula i-porosity ku-50-70% (≈60% ngokulungile) ukufeza i-Gurley 20-100s/100cc namandla e-dielectric ≥2kV yefilimu engu-0.13mm; sebenzisa ukwakheka kwezimbotshana zenethiwekhi ye-3D ene-tortuosity ephezulu (τ≈2.5-4) ukucindezela iziteshi zokuphuma eziqondile; ukwakha imbobo ye-asymmetric gradient pore enesendlalelo sesikhumba esiminyene (1-5μm) sokungeyona induku/i-insulation kanye nengaphakathi elinezimbotshana zokuphefumula; sebenzisa i-super-oleophobic/hydrophobic surface post-treatment ngaphandle kokuvaleka kwezimbotshana.

Lesi sihloko sihlinzeka ngezixazululo ezihlelekile zokuvimbela izinsalela zokunamathela nokopha okunamathelayo uma usebenzisa i-PTFE itheyiphu yokushisa ephezulu ukuvikela iminwe yegolide ye-PCB ngesikhathi somhlangano we-SMT. Ukuhlaziywa kwembangela yezimpande: izinsalela zivela ekuhlulekeni okuhlangene noma ukudluliswa okuhlangene; ukopha kwenzeka ngenxa yokwehla kwe-viscosity kanye nokuchichima kokunamathela ngaphansi kokushisa okugelezayo. Isixazululo esiyinhloko ukukhetha itheyiphu efanele: i-silicone PSA enokuphakama kwesikhashana okungu-≥300°C, okuqhubekayo ≥260°C, ukujiya okuphelele okungu-0.08-0.13mm okunezendlalelo ezinamathelayo ezinamathelayo ezihlangene eziphezulu, nesitifiketi esivimbela ukopha/insalela. Ukulawula inqubo yezinyathelo eziyisithupha: ukuhlanzwa kwangaphambili kwe-lamination nge-IPA; I-lamination ye-zero-tension nge-air evacuation egcwele; iphrofayili yethempelesha elungiselelwe ukugeleza kabusha ngokufudumeza okuthambile (<2°C/s); ukuxebuka okubandayo ngaphansi kuka-50°C nge-engeli engu-180°; ukucubungula ngokushesha phakathi kwamahora angama-24 nokusetshenziswa kanye kuphela; ukuphatha ukwehluleka ngokusula kwe-IPA kanye nokuhlolwa kwesikhulisi esingu-40-50x. Kuma-PCB anezinhlangothi ezimbili, buyisela itheyiphu entsha ngaphambi kokucutshungulwa kohlangothi lwesibili.

Lesi sihloko sinikeza isiqondiso esihlelekile sokuvimbela imibimbi engutsheni ye-PTFE enezinga lokushisa eliphezulu ngesikhathi sokushisa. Imibimbi ibangelwa ngokuyisisekelo ukuncipha kokushisa okungalingani kanye nokucindezeleka okungaguquki. Izixazululo zihlanganisa ukugeleza komsebenzi okugcwele: ukulawulwa kwe-substrate yezinto ezingavuthiwe (ukukhishwa okuphelele kwe-dewaxing / ukushisa ukuze kuqedwe ukucindezeleka kwangaphakathi); ukukhulelwa nokomisa (izingubo ezincanyana eziningi, i-gradient yokushisa emnene, ama-drive rollers asebenzayo); isilawuli sesithando somlilo (i-1-3% i-overfeed yesibonelelo sokuncipha okushisayo, isilawuli se-micro-tension se-closed-loop, ukufana kwezinga lokushisa okuguquguqukayo phakathi kuka-±5°C, ijika lokupholisa le-gradient preheating-sintering-cooling, izithando zomoya ezintantayo njengesixazululo esilungile, amarola okusakaza agobile); ukupholisa nokusetha (ukupholisa kancane kancane, gcina ukusabalala kuze kube ngaphansi kuka-100°C, ukupholisa okugcwele ngaphambi kokusongwa); ukuqapha okuku-inthanethi ngokuhlola ukukhanya okuqinile nokuskena kwe-infrared.

Lesi sihloko sifaka izidingo zesilinganiso sokupholisa ngesikhathi se-PTFE i-high-temperature sintering cloth. Ngemva kokucwilisa ku-380-400 ° C, indwangu kufanele idlule ngokushesha endaweni ezwela icrystallization engu-310-315°C. Izinga lokupholisa elinconyiwe okungenani lingu-30-50°C/min (indwangu encane ingafinyelela ku-100-200°C/min ngokupholisa komoya). Ukupholisa okusheshayo (ukucisha) kukhiqiza ubucwebe obuphansi (45-50%), bukhipha izimbotshana ezithambile, eziqinile ezinezindawo ezibushelelezi, ukunamathela okuqinile, ukusebenza okuhle kakhulu okungamanti, nokumelana ne-delamination nokuqhekeka. Ukupholisa kancane (ukupholisa kwesithando somlilo) kubangela ukucwebezela okuphezulu (60-70%), okubangela ukunamathela okuqinile, okubolayo okujwayele ukushwabana, ukuxebuka kanye nama-microcracks.

Lesi sihloko siqhathanisa izinga lokushisa legumbi nokuvuthwa kwezinga lokushisa eliphezulu kwe-adhesive ezwela ukucindezela kwe-silicone ye-PTFE tape. Ukuvuthwa kwezinga lokushisa eliphezulu (120-180°C) kudala amanethiwekhi aminyene axhumene anamandla okuhlangana aqinile, okuvimbela insalela enamathelayo ngemva kokuxebuka. Yakha amabhondi okunamathisela amakhemikhali anezingxenye ezingaphansi ze-PTFE ngokusebenzisa i-primer co-curing, eqeda ubungozi be-delamination. Ukuvuthwa kwezinga lokushisa eliphezulu futhi kususa ukuguquguquka kwamangqamuzana aphansi ngaphambi kokubeletha, kuvimbela ukubhamuza nokungcoliswa kukawoyela we-silicone ngesikhathi sokushisisa kokuqala.

Lo mhlahlandlela uhlanganisa ukukhethwa kwetheyiphu ye-PTFE yokushisa okuphezulu yokubumba umjovo wokubumba kanye nezinhlelo zokusebenza zokulwa nezinti. Ukukhetha okusekelwe emazingeni okushisa: ≤260 ° C kumapulasitiki ajwayelekile (i-tape evamile ye-silicone ye-PSA, 0.13-0.18mm); I-260-300 ° C yepulasitiki yobunjiniyela bezinga eliphezulu lokushisa njenge-PC, i-PA66, i-POM (i-adhesive ye-silicone yezinga eliphezulu, i-0.18-0.25mm); 300-400°C ye-PEEK, LCP, PPS eduze nabagijimi abashisayo (itheyiphu yokunamathisela iyehluleka; sebenzisa indwangu ye-PTFE enganamatheli noma ifilimu ye-PFA). Ukukhetha okusekelwe ezintweni ezibonakalayo: izinto ezicashile zidinga ukukhishwa okuphezulu okuhlanzekile kwe-PTFE; izinto ezigcwele ingilazi/amaminerali zidinga itheyiphu engagugi engu-0.25mm+; izithasiselo ezonakalisayo zidinga ingcina ekwazi ukumelana namakhemikhali kanye ne-substrate eminyene; izinhlelo zokusebenza ezizwela i-static zidinga itheyiphu ye-PTFE ephikisana ne-static.

Indwangu yokushisa ephezulu ye-PTFE yenziwa ngokunamathisela i-PTFE phezu kwendwangu ye-fiberglass enamandla amakhulu, enikeza amandla aqinile, ukumelana nokushisa, izakhiwo ezingabambeki, ukumelana namakhemikhali, nokungqubuzana okuphansi. Izicelo ezimqoka zihlanganisa: ukuthunyelwa kwezimboni (ukupakishwa kokunciphisa ukushisa, ukubhaka ukudla, okomisa izindwangu, ukomisa amaphepha/ifilimu); indwangu yokubumba ehlanganisiwe kanye nama-cushion liners ashisayo; amakhethini okuvikela amakhethini kanye namajakhethi okushisa ashisayo; motor kagesi kanye transformer insulation; ukwakha ama-sliding bearings nezisekelo zamapayipi; ukuhlunga kwamakhemikhali kanye nokuvala ama-valve ezindaweni ezigqwalile. Amandla aqine kakhulu aqinisekisa ukuqina ngaphansi kwengcindezi, ukudabuka, ukuguquguquka okuphindaphindiwe, kanye nengcindezi yemishini yezinga eliphezulu lokushisa kuzo zonke lezi zinhlelo zokusebenza ezisindayo ezihlukahlukene.

Ngesikhathi sokucwiliswa, izinhlayiya ze-PTFE endwangu ye-fiberglass zincibilika ngaphezu kuka-327°C, zicekela phansi i-lamellae egoqiwe yoqobo kanye nemingcele yezinhlayiyana ukuze zakhe ukuncibilika kwe-amorphous. Lapho ipholisa, i-PTFE iphinda icwebe ibe ngama-spherulites akhiwe ama-lamellae amise okwe-radially, anobukristalu obusukela ku-50–70%. Izinga lokupholisa linquma ukuphelela kwekristalu: ukupholisa kancane kukhiqiza icrystallinity ephakeme, ama-spherulite amakhulu, ubulukhuni obukhulu; ukucisha ngokushesha kunikeza ama-spherulite amahle kanye nokuguquguquka okuthuthukisiwe.