Opanga nsalu za Teflon zotentha kwambiri amawonetsa kuti kuwongolera kuzizira ndi njira yolunjika komanso yothandiza kwambiri yowongolera kristalo. PTFE itatha kusungunuka pamwamba pa 380 ° C, maunyolo a maselo amapangidwa m'magalasi a galasi pamene akudutsa mulingo wapamwamba kwambiri wa kutentha kwa 310 ~ 315 ° C panthawi yozizira. Kuzizira kumatsimikizira kuchuluka kwa chigawo cha kristalo ndi kapangidwe kakang'ono ka zokutira.
1. Kuzizira kofulumira (kuzimitsa) kwa crystallinity yochepa
Pamwamba pa nsaluyo amazizidwa mwachangu kudzera pa makatani a mpweya wozizira, ma roller ozizira kapena matanki amadzi otentha. Unyolo wa mamolekyulu amawumitsidwa asanakonzedwe mokhazikika, ndikupanga tinthu tating'ono tating'ono tating'ono topanda ungwiro. Chophimba chomwe chapezedwa chimakhala ndi mawonekedwe ofewa komanso kulimba mtima kwambiri ndikukhathamiritsa kopanda ndodo, pomwe kuuma kwake ndi kukana kuvala kumachepetsedwa pang'ono.
2. Kuzizira pang'onopang'ono (kuzizira) kwa crystallinity yapamwamba
Chigawo chosungira kutentha chimakonzedwa potulukira ng'anjo yotentha, kapena nsaluyo imakhazikika pansi ndi ng'anjoyo pamtunda wochepa kwambiri wa 10 ~ 50 ° C / h. Izi zimapangitsa kuyenda kokwanira kwa maunyolo a maselo kuti apange ma spherulites akulu ndi athunthu. Chophimbacho chimadzitamandira kuuma kwakukulu, kukana kuvala kwapadera komanso kukhazikika kwa mawonekedwe, komabe ndi kusinthasintha kochepa komanso kuwonjezeka kwa brittleness.
II. Njira Yothandizira ndi Kuwongolera Zinthu
Pamaziko a kuzirala mlingo malamulo, zotsatirazi wothandiza njira akhoza kupititsa patsogolo crystallinity wa PTFE zokutira.
1. Sintering kutentha ndi kugwira nthawi
Zinthuzo ziyenera kutenthedwa mpaka 380 ~ 400 ° C ndikusungidwa kwa nthawi yokwanira kuti zisungunuke makhiristo oyambirira ndikuchotsa mbiri yakale yotentha. Kusakwanira kwa sintering kudzasiya ma kristalo otsalira, zomwe zimapangitsa kuti crystallinity ikhale yokwera kwambiri komanso yogawidwa mosagwirizana.
2. Kuchepetsa pambuyo pa chithandizo
Kwa zokutira zokhala ndi crystallinity yotsika yomwe imapezeka ndi kuzizira kofulumira, kukula kwa kristalo wachiwiri ndi kuthetsa kupsinjika kwamkati kumatha kuzindikirika ndi chithandizo cha kutentha kosalekeza pa 300 ~ 320 ° C kwa maola angapo ndikutsatiridwa ndi kuzizira pang'onopang'ono, komwe kumawonjezera kuwala kwa kristalo.
3. Zopangira maselo kulemera
Kuchuluka kwa ma molekyulu a PTFE kumakhala ndi kukhuthala kwakukulu komanso kutsika kwa unyolo wa maselo, zomwe zimapangitsa kuti pang'onopang'ono crystallization. Pansi pazikhalidwe zomwezo zozizira, zimakhala zosavuta kukonzekera zokutira ndi crystallinity yochepa.
4. Zowonjezera zida zowonjezera
Mulingo waung'ono (0.1% ~ 1%) wa zodzaza organic kapena ma copolymers opangidwa ndi perfluorinated amatha kupereka kuchuluka kwa nuclei ya kristalo wambiri ndikuyenga kwambiri njere zamakristalo. Ngakhale sichingasinthe kwambiri mawonekedwe onse a crystallinity, imakulitsa bwino mawonekedwe a crystal microstructure.
III. Kuwongolera Kwakukulu kwa Multi-Layer Coating Production
Nsalu ya Teflon yotentha kwambiri imapangidwa ndi njira zambiri zoyamwitsa komanso zopangira sintering ndi zokutira zomwe zimasonkhanitsidwa pang'onopang'ono, zomwe zimafuna kuwongolera njira motere.
1. Interlayer crystallization kugwirizana
Kusiyanasiyana kwakukulu kwa kuzizira pakati pa zigawo kumayambitsa kusakanikirana kwa crystallinity ndi kupanga kupsinjika kwa mkati, zomwe zimapangitsa kuti kupaka kwazitali kukhale kovuta kwambiri. Ndibwino kutengera kuziziritsa pang'ono kwa zigawo zapakati, ndikukhazikitsa kuziziritsa kolunjika kofulumira kapena pang'onopang'ono kokha kwa wosanjikiza wakunja malinga ndi zofunikira zopanga.
2. ❖ kuyanika makulidwe zotsatira
Zopaka zokhuthala zimavutika ndi kuziziritsa kwa asynchronous pakati pa pamwamba ndi wosanjikiza wamkati. Mkati wosanjikiza umakonda kupanga crystallinity yapamwamba chifukwa cha kutentha kwapang'onopang'ono. Ndikofunikira kukulitsa nthawi ya sintering kuti mutsimikizire kutentha kofanana kwa zokutira zonse musanagwiritse ntchito njira zoziziritsa zolumikizana.
3. Kufanana kwamphamvu pakuzizira
Kukakamira komwe kumagwiritsidwa ntchito pansalu pagawo lozizirira kumakhudza momwe ma unyolo a cell amapangidwira, omwe amakwatirana ndi njira ya crystallization ndipo amatsimikizira kuti kristalo yomaliza imapangidwanso komanso kukhazikika kwamtundu. Kuwongolera kogwirizana ndi kolondola ndikofunikira.
IV. Kuzindikira Kwambiri kwa Crystallinity
Differential Scanning Calorimetry (DSC) iyenera kutengedwa kuti itsimikizire crystallinity pambuyo pa kusintha kwa ndondomeko. Chitsanzo cha 5 ~ 10mg chophimba chimatenthedwa pa mlingo wa 10 ° C / min kuti ayese enthalpy yosungunuka. The crystallinity imawerengedwa pogawa enthalpy yoyesedwa yosungunuka ndi theoretical melting enthalpy ya 100% crystalline PTFE (pafupifupi 82J / g). Kuphatikizidwa ndi kukana kupindika, kukana kuvala ndi kuyesa kwina kwa magwiridwe antchito, zenera labwino kwambiri limatha kutsimikizika.
General Operation Mfundo : Kuti mupeze crystallinity otsika, khazikitsani kuzimitsa mwamsanga pambuyo sintering zonse; kuti mukhale ndi kristalo wokwera, sungani kutentha kosalekeza kufupi ndi 310 ° C kutsatiridwa ndi kuzizira pang'onopang'ono pambuyo pozizira kwathunthu.
