Yuav ua li cas xam txog tus cwj pwm ntawm polyamide vaj khoom rau kev siv hluv siab hauv thermal break?

Qhov Tseem Ceeb ntawm Qhov Tseem Ceeb ntawm Polyamide Vajvoob: Cov Lus Qhia Tseem Ceeb rau Kev Ua Haujlwm Hluv Siab Ntau

Tshuab Hluv Siab Txhua Lub Sijhawm (Tg) Yog Li Lus Qhia Tseem Ceeb rau Kev Phem

Txheej ntawm kev txhuam hluv hluv lossis Tg muab tso ceeb tshaj plaws thaum polyamides pib xwm txheej nyob rau hauv kev txhuam hluv. Thaum kub txog li saum li cas, uas feem ntau nyob rau hauv qhov chaw ntawm 80 mus 120 degrees Celsius rau cov khoom siv tshaiv tshiab, cov hmoob polymer yuav mob dua thiab cov khoom siv yuav dhau 60% ntawm nws qhov tsim nyob ib si theem raws li kev kho tshuam pub tseg hauv Journal of Polymer Science xyoo npog. Nyob rau hauv kev tshen tsev, khiav cov khoom siv uas Tg lawm nyob rau 30 mus 50 degrees siab dua li qhov feem ntau pom nyob rau hauv dej tshav kub yuav pab tau zoo dua rau kev tsim qhov chaw. Qhov tshawb nrhiav zoo tuaj yeem pom yog tias nws tso cai 80% ntawm qhov tsim taw tes ua ntej thaum tshawb nyob rau 80% ntawm Tg, qhov kawg tsawg tshaj 0.2% hauv qhov kub ntawm 50C mus rau Tg, thiab qhov dielectric yuav tsum zoo ib yam thiab tsis txo 10% los ntawm qhov ntaus taw ua ntej.

Kev tiv thaiv kev ntxoov ntxooj ntev nyob rau hauv kev txhuam hluv cyclical

Kev rov ua siab thiab sib txuas siab tshaj tawm tuaj yeem tshwm sim rau kev hloov form nyiaj ntawm cov khoom siv los ntawm polyamide rau kev tig siab. Thaum muab mus ntau dua 5,000 teev nyob rau hauv lub tsev kawm, cov ntaub ntawv version ntau dua tuaj yeem tshwm sim 0.12 mm ntawm kev hloov form uas tsis rov qab, tab sis tsis txhob cia li 89% ntawm lawv lub zog tsho kom nyob ib leeg raws li ISO 899-1. Cov khoom siv carbon fiber reinforced tau txo dej nkhaus siab tshaj tawm ntau dua 92% kom compared to standard materials. Cov ntaub ntawv tshiab dua kuj muaj kev pab ntau dua, tshwm sim kev hloov form tsawg dua 0.01% per hour thaum muaj kev puas tsuaj ntawm 80% ntawm lawv lub zog tshaj plaws raws li ASTM D2990. Qhov tseem ceeb tshaj plaws ntawm cov kev pab no yog qhov uas tau pab polyamides tso ob npaug mus rau aluminum's expansion properties, tsis txhob ntau dua 5% difference. Qhov kev sib npaug no pab tiv thaiv cov teeb meem interface uas yuav tshwm sim thaum cov layer hloov siab thiab sib tshav siab.

Kev Nyiaj Nyawm Kawg Nraum Polyamide thiab Aluminum: Sauv Xam Kev Txaus Siab Nyob Rau Saum Kev Txhaws Txoj Ceev

Cov Qauv Kev Nyiaj Nyawm Nyob Rau Hauv Cov Chav Sib Puas Xwm Polyamide-Aluminum

Kev nyiaj nyawm tshwm yeem los ntawm kev sib ntxig mekhanik thiab kev nyiaj nyawm kim hauv. Kev txheej txheem pob (Ra ≥ 3.2 µm) pab polyamide rov saum, thaum cov duab kim uas muaj amine zoo liag pab ntau dua rau kev sib nyiaj nyawm covalent nrog aluminum oxides. Cov kev txhim kho sib txuas uas sib chg plasma thiab cov cuab yeej pab nyiaj nyawm tuaj yeem nce qhov tsim nyiaj nyawm kawg nraum los ntawm 18% tshaj qhov tsis tau txhim kho, yog li nws pab ntau dua rau kev txaus siab dhau los.

Sauv Xam Microstructural ntawm Kev Sib Separation Kawg Nraum Nyob Rau Ua Pib Ntau

Kev sov thiab cool (ΔT = 80°C) cuam tshuam rau ib qhov kev phom sij tshiab ob peb qhov: polymer softening nyob rau Tg, microcracking nyob rau hauv oxide layer, thiab thaum kawg yog hybrid adhesive-cohesive failure. Scanning electron microscopy pom tias kev sib tso tawm feem ntau nyob rau qhov chaw uas muaj ntau zog tshav teeb ntau tshaj 15 ppm/°C, tshaj tshav rau sab nraud ntawm qhov interface uas nyiaj nyawm yooj yooj.

Daim Puv Txog: Qhov Chaw Sib Tham Puas Tsuaj Hauv Lub Kevkas Rau Lub Hoob Kas Nyiaj Hauv Yule

Ib qhov kev saib xyuas uas tshwm sim hauv 2023 ntawm ib txug pej xeem muaj nyob twg sib tham txog cov thermal breaks tsim los ntawm polyamide thiab aluminum. Muaj li phau ib ncig ntawm cov kis tau npaj no tau nyob nrog qhov puas tsuaj tshaib hauv tsib xyoob pib. Nrhiav ntau dua, cov neeg tshawb fawb pom tias muaj ob peb yam teeb meem tshwm sim sib npaug. Ntau yam muaj adhesive coverage tsawg hauv qab 85% qauv tswj. Lwm yam kuj tau nyob nrog qhov expansion cycles loj hlob uas tshwm hauv 0.15 mm per meter, thaum li lwm yam kuj muaj qhov chaw tsis muaj sealing uas ua rau dej nkag mus. Thaum cov neeg tshawb fawb nrhiav cov duab tshwm sim tom qab puas tsuaj, lawv pom ib yam tseem ceeb: muaj hydroxyl groups nyob hauv qab ib ncig hauv qhov chaw puas tsuaj kom compared to cov chaw zoo. Qhov no txhais tau tias kub tuaj yeem tshwm sim rau chemical breakdown processes hauv siab xyoob.

Qhooj kev sib tshuam nyob rau hauv cov thermal break uas tsim los ntawm polyamide: Mus rau qhov crack mus rau kev sib tshuam nrog cheeb tsheej

Kev ntxig ntawm qhov ntxig tshwm sim los ntawm kev sib txawv ntawm kev ua haujlwm rau kev ua rau sov

Kev sib txawv ntawm kev rov qab los thiab aluminum tsim tau cov kev ua haujlwm sib txuas cyclical. Ntau yam kev xam xeeb los ntawm NIST hais tias thaum 2023 pom tias thaum rov ua haujlwm ntau dua (ΔT ≥ 80°C) feem ntau dua 5,000 zaug, feem ntau lom neeg feem ntau dua 40%. Cov microcracks pib nyob rau hauv cov chaw uas muaj kev ua haujlwm zoo li cov rooj fastener thiab ntxig ntau dua 0.3 mm/xyoo nyob rau hauv qhov chaw curtain wall, uas tsis tuaj yeem tshwm sim.

Ntawm kev sib tshuam nrog cheeb tsheej thiab kev sib tshuam nrog kev ruaj khov ntawm kev ruaj ntseg

Kev sib tshuam nrog dej tsis zoo rau polyamide los ntawm plasticization—uas yog qhov Tg hloov siab dua 15–25°C nyob rau 85% RH—thiab hydrolysis, uas yog qhov tshwm sim los ntawm kev sau amide. Nyob rau hauv qhov kev cai EN 14037 (70°C, 95% RH), kev ruaj ntseg hloov siab dua 30% tom qab 1,000 teev, thiab kev tsis txaus siab pib nyob rau hauv cov chaw oxidized aluminum-polyamide uas hloov siab dua los ntawm kev sib tshuam nrog sov thiab dej.

Qhov kev txhaam xeeb hauv cheebtsheej: Qhov tshuab ntau yas li ntawm qhov tseem ceeb hauv chaw tsim

Txhawm tias cov khoom no muaj qhov zog tshuab ntau tshaj 120 MPa hauv chaw tsim, tab sis nyob rau ib hlis paub tias muaj ib hlis ntawm rau hlis thermal break yuav tsum raug mob thaum siv cov polyamides uas peev tawm tias "zog siab". Qhov teeb meem seem tias los ntawm cov neeg kho tshuab uas cog tswj ntau heev rau qhov zog ruaj khov, tab sis tso tseg qhov khib nyiab, qhov khib nyiab, thiab qhov khib nyiab, thiab lwm yam khib nyiab uas tshwm sim thaum siv hluas. Thaum saib hauv qhov kev siv hluas, cov khoom tsim los rau kev tiv thaiv kev tso tseg (creep resistance) feem ntau zoo dua li kev txwv ntau tshaj plaws. Cov khoom no muaj qhov tshuab ntau tshaj 1% nyob rau 70 degrees Celsius nyob rau hauv 10 MPa, uas yog qhov pab tias nws ua haujlwm zoo hauv 9 hlis ntawm 10 hlis hauv lub tebchaws Yuroop. Qhov no hu rau tus neeg tsim kom tsis txhob cog tswj ib yam metric.

Kawm Txog Qhov Loj ntawm Ntau Yeeb: Qhov Kev Hloob Siab thiab Qhov Tswj Hwm ntawm Shear ntawm Polyamide-Aluminum Sib Thooj

Qhov Tswj Hwm ntawm Shear Load Sib Poob rau hauv Qhov Chaw Ua Hlis Ua Termally

Lub tswv yim ntawm kev tsim kho nyob ntawm qhov tseem ceeb tias yuav tsum muaj kev sib poob shear load zoo li cas ntawm ob lub profile aluminum los ntawm polyamide core material. thaum cov neeg tsim kho tsim kho tau raws li qhov xav, lawv feem ntau tuaj yeem txog 85% lossis dav dua qhov tswj hwm ntawm kev sib poob load, vim muaj kev sib piv zoo ntawm polymer chains thiab qhov tseem ceeb ntawm crystallinity hauv material. cov kev sim pom tias thaum siv polyamides uas muaj viscosity tsawg dua, feem ntau muaj kev pab hloov pauv ntau dua los ntawm 18-22% nyob rau hauv teb nthuav kub txog li 70 degrees Celsius rau hauv curtain wall applications uas raug nthuav kub thiab cool dua dua. qhov no txhais tau tias cov khoom siv zoo dua thaum ntev tshaj taig rau hauv kev siv nyob rau hauv chaw nyob.

Qhov Thresholds ntawm Slip Initiation Nyob rau hauv KeV Ntshav thiab Mechanical Stress

Nyob rau hauv qhov chaw kho mob, polyamide-aluminum interfaces tiv tauj 4–6 kN/mm² shear stress ua ntej khiav. Tab sis, cov ntaub ntawv saum npoo looj pom tias muaj kev phom sij li 30–40% thaum tso rau hauv kev sib txuas kho plhaub (+80°C/–20°C) thiab kev nyiag siab uas muaj zog los ntawm dej choo. Qhov sib txawv no txhais tau tias yuav tsum muaj kev tsim kho tsha tshaj plig uas sim qhov sib txuas kho plhaub-nyiag siab nyob hauv keev ceeb.

Cov ntaub ntawv: ASTM E2129 Txhawj Xeeb thiab Nws Qhov Sim

Daim ntawv qhia ASTM E2129 muab cov kev txheeb xyuas zoo tshaj plaws rau peb, thaum kawg nws tsis pom ob peb yam uas tseem ceeb nyob hauv kev xwm yeem. Piv txwv li, cov khoom feem ntau tau txais sijhawm ntev uas hu ua long term creep uas lawv hloov form li 12 mus 15 percent hauv 1000-sijhawm kev sim. Tom qab no yog hygrothermal exposure uas tuaj yeem cuam tshuam kev nyiaj ruaj li suav nrog 25 percent. Thiab tsi pub saib xyuas thermal ratcheting, uas kev phom sij tuaj yeem nce 2 los 3 zaug tom qab 300 cycles lossis ntau dua. Thaum cov neeg kho tshuaj sib sau kev sim thermal loading cyclical nrog ASTM protocols, lawv tau txais cov ntsiab lus txaus siab tshaj rau kev txheeb tsis cuam tshuam. Cov kev suav zais hais tias kev txheeb no nce qhov txaus siab li 60 mus 75 percent rau kev kho tshuaj facade. Qhov no tsim txoj hlua tshwj tsis khiav yog tias xav txheeb kom meej meej txog systems ua ntej xaiv.