Thermal uniformity-qhov sib xws ntawm qhov kub thiab txias thoob plaws txhua cheeb tsam thiab kab noj hniav- yog qhov dawb huv grail ntawm kub khiav molding. Thermocouples yog lub hauv paus sensors rau kev ntsuam xyuas thiab ua tau zoo ib yam. Kab lus no piav qhia yuav ua li cas siv cov ntaub ntawv thermocouple kom sib npaug ntawm qhov kub thiab txo qhov sib txawv.
Defining Uniformity. Thermal uniformity txhais tau hais tias txhua qhov taw tes hauv cov dej yaj uas yuav tsum nyob ntawm qhov kub thiab txias tiag tiag. Hauv ntau- kab noj hniav pwm, txhua qhov kab noj hniav yuav tsum tau yaj ntawm cov viscosity zoo ib yam. Hauv ib qho -kab kab noj hniav pwm, lub manifold yuav tsum tsis muaj qhov kub thiab txias uas ua rau cov dej ntws tsis txaus. Uniformity feem ntau yog ntsuas raws li tus qauv sib txawv ntawm qhov kub thiab txias ntawm ib cheeb tsam.
Lub luag haujlwm ntawm Thermocouple Placement. Txhawm rau ntsuas qhov sib xws, cov thermocouples yuav tsum muab tso rau ntawm qhov chaw sawv cev. Hauv ib qho manifold, tso cov sensors ze ntawm qhov nkag, ntawm ceg taw tes, thiab ze rau txhua qhov nkag nkag. Hauv nozzles, tso cov sensors ntawm tib qhov chaw txheeb ze (piv txwv li, 10 mm saum toj kawg nkaus). Kev tsis sib haum xeeb ua rau kev nyeem ntawv tsis sib xws, ua kom tsis sib xws zoo li phem dua li nws. Daim ntawv qhia txhua cheeb tsam lub thermocouple txoj hauj lwm kom meej.
Zone-rau-Zone Offset Calibration. Txawm tias muaj cov thermocouples zoo ib yam, qhov sib txawv me ntsis hauv qhov loj me, thermal roj, lossis sensor calibration tsim offsets. Thawj kauj ruam mus rau uniformity yog los them rau cov offsets. Thaum lub sijhawm khov kho- lub xeev ntau lawm (tsis muaj kev txhaj tshuaj), teeb tsa txhua thaj chaw rau tib qhov chaw thiab sau cov ntawv nyeem tiag tiag. Yog tias ib cheeb tsam nyeem 2℃siab dua, siv qhov -2℃offset hauv tus maub los. Rov ua dua kom txog thaum tag nrho cov cheeb tsam nyeem tib tus nqi. Qhov no yog hu ua "zone balancing."
Steady-State vs. Dynamic Uniformity. Uniformity yuav tsum tau khaws cia thaum txhaj tshuaj, tsis yog thaum so. Cov theem txhaj tshuaj txias cov lus qhia nozzle thaum cov khoom txias nkag mus. Cov thermocouples ceev ceev ntes cov sijhawm no. Yog tias qee thaj chaw rov qab sai dua li lwm tus, lawv yuav kub dua thaum lub voj voog tom ntej. Siv cov ntaub ntawv thermocouple los kho cov khoom siv hluav taws xob hluav taws xob, tsis yog cov teeb tsa xwb. Qee tus tswj hwm muab kev hloov pauv hloov pauv uas txhawb nqa lub zog rau thaj chaw uas txias dua.
Daim ntawv qhia Temperature Profiles. Rau cov manifolds loj, siv lub tes tuav thermocouple lossis thermal imaging lub koob yees duab los qhia qhov kub thiab txias thaum lub sijhawm sim. Sib piv nrog cov ua - hauv cov ntawv nyeem thermocouple. Yog hais tias lub manifold muaj lub hotspot tsis npog los ntawm ib tug sensor, xav txog ntxiv ib tug thermocouple. Niaj hnub nimno manifolds tuaj yeem muaj txog li 8 sensors ntawm lub phaj splitter.
Cua sov Zoning thiab Thermocouple Pairing. Yuav kom ua tiav qhov sib xws, lub manifold yuav muaj ntau lub tshuab cua sov rau ib ceg. Txhua lub rhaub yuav tsum muaj nws tus kheej thermocouple kom tso cai rau kev tswj hwm ywj pheej. Tsis txhob siv ib lub thermocouple los tswj ob lub tshuab cua sov- uas xav tias cov cua sov coj zoo ib yam, uas tsis tshua muaj tseeb.
Kev cuam tshuam ntawm cov kab txias. Cov kab dej txias hauv pwm tuaj yeem tshem tawm cov cua sov tsis sib xws ntawm cov manifold. Thermocouples nyob ze cov cua txias yuav nyeem qis dua cov nyob deb ntawm lawv. Siv cov ntawv rwb thaiv tsev ntawm manifold thiab pwm kom txo cov nyhuv no. Yog tias tsis muaj kev rwb thaiv tsev, siv cov ntaub ntawv thermocouple los teeb tsa thaj tsam offsets uas them rau cov qauv txias.
Rwb thaiv tsev zoo. Tsis zoo rwb thaiv tsev nyob ib ncig ntawm lub manifold ua rau kub poob, ua rau uniformity nyuaj. Thermocouple nyeem los ntawm cov cheeb tsam sab nrauv yuav qis dua, xav tau lub zog cua sov siab dua. Qhov no ua rau muaj kev pheej hmoo ntawm overheating cov cheeb tsam sab hauv. Xyuas kom meej tias tag nrho cov manifold npog thiab cov pa tawm ntawm huab cua yog insulated zoo. Tshawb xyuas cov ntawv nyeem thermocouple tiv thaiv thermal simulations.
Kev txheeb xyuas lub sijhawm. Uniformity tuaj yeem ya raws lub sijhawm vim lub tshuab hluav taws xob laus lossis thermocouple drift. Ua ib qho kev txheeb xyuas qhov tsis sib xws hauv peb lub hlis twg. Teem tag nrho cov cheeb tsam mus rau ib qho chaw teeb tsa, khiav cov pwm yam tsis tau txhaj tshuaj rau 30 feeb, thiab sau tag nrho cov cheeb tsam kub. Qhov ntau (max – min) yuav tsum nyob rau hauv 2℃rau siab -pwm precision. Yog tias nws siab tshaj 5 degree, tshawb xyuas thiab rov kho dua lossis hloov cov sensors.
Case Study: 32-Cavity Cap Pwm. Cov pwm no muaj qhov kub thiab txias ntawm 8℃thoob plaws kab noj hniav. Qhov chaw ntawm cov kab noj hniav kub tau undersized; los ntawm cov kab noj hniav txias, flashed. Siv lub ntsuas ntsuas ntsuas ntsuas ntsuas ntsuas ntsuas, txhua cheeb tsam tau offset los nyeem tib yam ntawm qhov chaw teeb tsa. Tom qab ntsuas qhov ntsuas, qhov ntau tau poob mus rau 1.5 degree, thiab qhov sib txawv ntawm qhov hnyav txo los ntawm 70%.
Advanced Techniques. Qee lub tshuab siv ntau lub thermocouples rau ib cheeb tsam (piv txwv li, ib qho ntawm lub rhaub, ib qho ntawm lub taub) thiab suav qhov ntsuas kub. Los ntawm kev tswj xyuas qhov gradient tas li, lawv ua kom cov cua sov sib txawv. Lwm tus siv cov ntsuas kub yaj (flush-mounted thermocouples hauv cov kwj deg) los ntsuas cov yas, tsis yog hlau. Cov direct sensors no muab qhov kawg uniformity check.
Kev khaws cia. Khaws ib lub log ntawm cheeb tsam kub nyeem ntawv raws sijhawm. Cov kev xav tau nthuav dav ntxiv qhia txog cov teeb meem tshwm sim (piv txwv li, lub rhaub dej tsis ua haujlwm lossis lub thermocouple drifting). Los ntawm kev ntes cov no thaum ntxov, koj tuaj yeem rov ua kom zoo ib yam ua ntej tsim cov khoom seem.
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