Lokacin da tef ɗin PTFE ya buƙaci ya watsar da zafi - alal misali, haɗawa da wani ɓangaren wutar lantarki zuwa ɗakin zafi - manne Layer dole ne ya yi abubuwa biyu a lokaci ɗaya: canja wurin zafi kuma riƙe da ƙarfi. Ƙara abubuwan da za su iya ɗaukar zafi (alumina, boron nitride, da sauransu) yana inganta haɓakar zafin jiki amma kusan koyaushe yana rage mannewa.
Kalubalen shine haɓaka canjin zafi yayin rasa ɗan mannewa gwargwadon yuwuwar . Amsar ta ta'allaka ne a cikin sigogin filler guda uku: Girman barbashi, siffar barbashi, da adadin lodawa.
Aokai PTFE ya haɓaka haɓakar thermal Kaset na PTFE don kayan lantarki da aikace-aikacen masana'antu. Wannan labarin ya bayyana yadda girman barbashi, ilimin halittar jiki, da ɗora nauyi ke shafar cinikin-kashe, da kuma yadda za a tsara ma'auni mafi kyau.
Girman Barbashi - Kashe Ciniki Mai Kyau
Girman barbashi yana sarrafa yadda masu filaye suka samar da hanyar sadarwa mai ɗaukar zafi da kuma yadda mannen ya jika saman haɗin gwiwa.
1. Fine barbashi (nano zuwa submicron)
Thermal sakamako: High surface area take kaiwa zuwa mafi barbashi-barbashi lamba maki, amma kuma mafi interfacial thermal juriya (phonon watsawa). Tsananin agglomeration yana iyakance haɓaka haɓakawa.
Tasirin mannewa: Kyawawan barbashi suna sha mai yawa na guduro da tackifiers, suna taurare abin da ake amfani da su. Takawar farko tana faɗuwa sosai. Gudun ruwa yana raguwa, rage jiko a kan ƙananan-makamashi na PTFE → ƙananan ƙarfin kwasfa.
Hukunci: Ba kasafai ake amfani da shi kadai ba. Fitattun filaye masu kyau suna ba da fa'idar zafi ta gefe amma suna lalata mannewa.
2. M barbashi (micron zuwa dubun microns)
Tasirin zafi: Ƙananan wuraren tuntuɓar amma mafi tsayin hanyoyin tafiyar da zafi na mutum ɗaya. Lokacin da aka tattara su tare tare da jagorar kauri mai mannewa, suna ba da kyakkyawan aiki ta jirgin sama.
Tasirin mannewa: Ƙananan yanki yana tallata ƙarancin guduro, yana kiyaye taushin mannewa. Duk da haka, idan barbashi suna da kauri kamar ko mafi kauri fiye da manne Layer (yawanci 25-100 μm), suna roughen da tef surface, rage tasiri bonding yankin, da kuma haifar da danniya taro maki.
Hukunci: Ana amfani da shi azaman kwarangwal na farko, amma dole ne ya zama ƙasa da kauri mai mannewa.
3. Maganin - haɗuwa da bimodal
Haxa ɓangarorin da ba su da kyau da lafiya a takamaiman ma'auni. Kyawawan hatsi suna cika ɓata tsakanin ɓangarorin da ba su da ƙarfi, suna samun tattarawa mafi kusa. Tare da jimlar nau'in nau'in filler iri ɗaya, ƙimar bimodal yana haɓaka wuraren tuntuɓar barbashi (mafi kyawun aiki) ko kuma, a madadin, ya kai ga ƙaddamarwar manufa tare da ƙarancin jimillar filler , yana barin ƙarin ci gaba da resin lokaci don adana mannewa.
Shawarar Aokai PTFE : Don maɗauri mai kauri μm 50, yi amfani da ƙananan barbashi na 20-30 μm da aka haɗe da ƙananan barbashi na 1-5 μm. Wannan tsarin bimodal shine mabuɗin don daidaita kaddarorin.
Barbashi Ilimin Halitta - Siffar Yana da Muhimmanci
Filayen da ba na sikeli ba suna daidaitawa yayin rufewa da bushewa, suna tasiri ta hanyar jirgin sama (Z-direction) halayen thermal da mannewa.
1. Filaye masu siffa ko siffa (misali, alumina mai siffar zobe)
Tasirin thermal: isotropic. Barbashi suna tari cikin sauƙi tare da kauri shugabanci, mai kyau don zubar da zafi ta jirgin sama.
Tasirin mannewa: Filaye masu laushi ba sa hana guduro gudu. Yana kiyaye kwararar sanyi da jikawar saman. Daga cikin dukkan sifofi a daidai ɗorawa, sassa suna riƙe da mafi kyawun mannewa - musamman maɗaurin farko.
Amfanin ma'auni: Mafi dacewa gaba ɗaya. Yana haɓaka riba mai zafi na Z-axis tare da ƙarancin mannewa.
2. Filaye masu laushi (misali, boron nitride, graphene)
Tasirin thermal: Babban al'amari rabo yana ba da kyakkyawan aiki a cikin jirgin sama, amma flakes suna daidaita daidai da ma'aunin, suna ba da haɓaka ta hanyar jirgin kaɗan - matalauta ga kaset PTFE waɗanda ke buƙatar canja wurin zafi a tsaye.
Tasirin mannewa: Flakes suna aiki kamar fina-finai na bangare, toshe kwararar filastik da kuma yanke takin farko sosai. Ƙaƙƙarfan gefuna suna haifar da damuwa, rage ƙarfin kwasfa.
Lalacewar ma'auni: Rashin dacewa don buƙatun zafi na jagorar Z, yana cutar da mannewa na asali. Ba a ba da shawarar azaman babban filler ba.
3. Fibrous ko rashin daidaituwa
Tasirin thermal: Babban al'amari na iya gina hanyoyin sadarwa a ƙananan lodawa.
Hukunci: Ba kasafai ake amfani da shi azaman babban filler ba; ƙaramin ƙari kawai azaman kayan haɗin gwiwa.
Loading Filler - Neman Tabo Mai Dadi
Yayin da ɗorawa na filler ke ƙaruwa, haɓakar zafin jiki yana tashi a hankali da farko, sannan yayi tsalle da ƙarfi a bakin kofa , sannan plateaus. Adhesion, duk da haka, yana raguwa ci gaba.
1. Karancin kaya (<30 vol)
Fillers tsibiran keɓe ne a cikin matrix na guduro mai ci gaba. Ƙarƙashin zafi da kyar ke inganta. Adhesion ya kasance kusa da PSA mai tsabta. Safe yanki don adana tack, amma thermal ribar sakaci.
2. Matsakaici-zuwa-high lodi (30-60 vol%) - taga mai mahimmanci
Barbashi sun fara taɓawa kuma suna samar da hanyoyin gudanarwa. Thermal conductivity yana tashi sosai. A halin yanzu, ci gaba da resin matrix ya zama rarrabuwa. Adhesive yana juyawa; Ƙarfin farko da bawo ya ragu sosai.
Wannan shine yankin ingantawa. Makasudin shine a yi aiki a ƙananan ƙarshen bakin kofa - babban isa don saduwa da ƙayyadaddun bayanai na thermal, ƙarancin isa don riƙe ci gaba da resin lokaci don mannewa mai karɓuwa.
3. Maɗaukakiyar lodi (> 60 vol)
Haɗaɗɗen barbashi yana rage jinkirin samun ribar zafi (Plateau). Resin ba zai iya cika dukkan gibba ba; vads form. Adhesive ya zama bushe, karye, kuma kusan mara tauri. Tef ɗin ya zama fim ɗin thermal mai rauni. Ma'auni na dukiya ya ɓace gaba ɗaya.
Bayanan kula na musamman don tef ɗin PTFE (silicone PSA): Silicone yana da ƙananan ƙarfin haɗin kai da rashin daidaituwar filler fiye da acrylic. Yana jure ƙananan madaidaicin lodin filler. Cike da yawa yana haifar da juzu'a.
Aokai PTFE empirical data : Don alumina mai siffar siffar siliki a cikin PSA na silicone, madaidaicin madaidaicin shine kusan 35-45 vol. Ana samun ma'auni mafi kyau a kusa da 40-45 vol% tare da rarraba bimodal. Sama da 55 vol%, mannewa ya zama mara karɓuwa ga yawancin aikace-aikace.
Takaitawa - Tsarin Ma'auni Mai Tsari Uku Cikin-Ɗaya
Don cimma kwanciyar hankali na thermal conduction–adhesion balance a PTFE high-zazzabi kaset:
Yi amfani da ɓangarorin ƙwanƙwasa (20-30 μm) azaman kwarangwal na farko - suna ba da haɓaka ta hanyar jirgin sama tare da ƙarancin mannewa.
Ƙara ƙananan barbashi (1-5 μm) don ƙirƙirar rarraba bimodal - ya cika ɓatacce, yana rage jimillar filler da ake buƙata, yana adana matrix resin.
Ajiye jimillar lodin filler a ƙaramin-tsakiyar kewayon ƙofa (kimanin 40-45 vol% don alumina mai siffar siliki a cikin PSA na silicone).
Iyakance filaye masu laushi ko fibrous zuwa <5 wt% idan an buƙata kwata-kwata - suna cutar da taki kuma suna ba da ɗan fa'ida ta jirgin sama.
Sakamakon: Tef ɗin PSA mai zafin jiki wanda a zahiri ya tsaya kuma yana dawwama.
Aokai PTFE yana kera kaset ɗin PTFE masu ɗaukar zafi ta amfani da wannan dabarar filler mai siffar bimodal. Za mu iya keɓanta maɗaukakin zafi da matakan mannewa zuwa aikace-aikacen ku.
Takeaway Karshe
Inganta thermal conductivity a cikin PTFE m kaset ko da yaushe yakar adhesion. Mafi kyawun sasantawa ya fito ne daga ɓangarorin sassa daban-daban + rarraba girman bimodal + lodin abubuwan da suka wuce . Guji flakes da zaruruwa sai dai idan aikace-aikacenku yana buƙatar takamaiman aiki na cikin jirgin kuma yana iya jure ƙarancin taki.
Don haɗin kai mai girma tare da zubar da zafi, tef ɗin PTFE mai ɗaukar zafi shine ingantaccen bayani. Tuntuɓi Aokai PTFE don abubuwan da suka dace da yanayin zafi da buƙatun kwasfa.
