Watt Density Revisited: Sib piv lub Cartridge rhaub rau cov khoom ua kom sov

Plastics processor muab tib lub tshuab cua sov rau hauv ob lub pwm sib txawv. Cov pwm muaj tib txoj kab uas hla, qhov hluav taws xob, tag nrho cov wattage, thiab cov chaw tswj. Lub tshuab cua sov siv tau ntau xyoo hauv thawj pwm (aluminium tooling rau qis-kub PP) thiab ua haujlwm zoo txhua lub sijhawm. Nyob rau hauv rooj plaub thib ob (siab-kub PEEK hauv stainless- cov cuab yeej hlau), lawv tawg tom qab ob peb lub hlis, nthuav tawm cov cim ntawm kev hnav xws li tsis muaj xim, bulging sheaths, lossis qhib circuits. Cov cua sov yog tib yam, tab sis cov txiaj ntsig sib txawv heev. Qhov tsuas yog qhov kev hloov pauv yog cov khoom siv tau zoo li qub thiab lub cuab yeej tuaj yeem nqus tau thiab kis tau zoo npaum li cas. Qhov no tshwm sim txhua hnub hauv kev lag luam thiab qhia txog qhov tseeb yooj yim: watt ceev yuav tsum sib phim tsis yog rau lub rhaub cov qauv tsim, tab sis kuj rau cov khoom muaj peev xwm hloov cov cua sov thiab tso dej.

Watt ceev, uas yog tag nrho cov wattage muab faib los ntawm qhov ua tau zoo rhuab saum npoo, qhia peb yuav ua li cas nyuaj lub sheath nto yuav tsum tau ua hauj lwm kom txav zog mus rau ib puag ncig nruab nrab:
\\\\text{Watt density (W/in²)}=\\frac{\\text{Total wattage}}{\\pi \\times \\text{diameter (in)} \\times \\text{heated length (in)}} \\]

(los yog W / cm² hauv metric tus nqi). Lub 500 W rhaub uas yog 6 ntiv tes ntev muaj li ib nrab ntawm watt ceev ntawm lub rhaub zoo tib yam uas yog 3 nti ntev. Lub tsev luv luv yuav tsum tau thawb ob zaug ntau zog los ntawm ib nrab ntawm ntau qhov chaw saum npoo av, uas ua rau lub plhaub kub ntau dua, txawm tias cov pwm teeb taw tes yog tib yam.

Cov ntaub ntawv sib txawv tuaj yeem tuav thiab tshem tawm cov cua sov kom deb ntawm lub hnab hauv ntau txoj kev. Copper (≈400 W/m·K) and aluminium (≈237 W/m·K) platens or blocks wick heat quickly, which means they can handle greater safe watt densities-usually 40–80 W/in² (62–124 W/cm²) in swaged designs-while maintaining the temperature of the wires inside below 900–1000 degree. Cov cuab yeej hlau (P20, H13) uas ua cua sov ntawm 25–35 W / m·K xav tau kev ceev faj ntau dua, feem ntau 20–40 W / in² (31–62 W / cm²). Txhawm rau kom qhov chaw qis qis qis dhau, cov pwm tsis muaj steel hlau (kwv yees li 15-20 W / m·K) yuav tsum tau qis dua. Cov yas, xws li PP, ABS, thiab siab -kev ua haujlwm zoo li PEEK, muaj cov khoom siv hluav taws xob tsawg (0.1–0.3 W/m·K), uas ua rau lawv nyuaj tshaj plaws los ua haujlwm nrog. Txhawm rau kom tsis txhob muaj kev kub ntxhov hauv cheeb tsam, kev puas tsuaj, lossis cov pa roj carbon deposition ntawm lub tshuab cua sov, watt ceev yuav tsum poob mus rau 5–15 W / in² (8–23 W / cm²) ncaj qha - tiv tauj lossis nyias- daim ntaub ntawv phab ntsa.

Cov ntawv thov uas siv cov kua immersion muaj cov qauv zoo sib xws tab sis tsuas yog rau cov kua hom. Cov roj thiab cov roj nyias (tsis tshua muaj viscosity, kub tshwj xeeb) txav mus los ntawm ntau thiab tuaj yeem yooj yim tswj cov nruab nrab mus rau siab watt ntom ntom (40-100 W / in² lossis ntau dua nrog kev ncig). Cov roj hnyav, cov roj hloov hluav taws xob, cov polymers molten, thiab cov syrups yog cov piv txwv ntawm cov kua dej khov uas tsis zoo ib yam thiab tsim cov txheej txheem ciam teb. Thaum cov kua dej qhov siab tshaj plaws ntawm cov yeeb yaj kiab kub (feem ntau ntawm 250 thiab 350 degree), nws yuav tawg, oxidise, lossis polymerise, uas ua rau coking. Coking yog ib qho nyuaj, carbonaceous deposits uas insulates lub sheath, ntxiab cua sov, thiab speeds li burnout. Rau cov roj teeb, cov kev txwv pom zoo mus rau 10-30 W / in², thaum rau cov xov xwm hnyav lossis degradable, lawv mus rau 5-15 W / in².

Muaj kev sib raug zoo tsis zoo ntawm kev ua haujlwm kub thiab qhov siab tshaj plaws watt ceev. Txhawm rau ua kom lub cua sov lub neej zoo ib yam, lub hom phiaj siab dua xav tau qis dua watt ntom. Lub tshuab tso cua sov hauv lub txhuas phaj uas khiav ntawm 400℃F (204 degree) tuaj yeem ua haujlwm ruaj ntseg 60 W / in² rau lub sijhawm ntev. Tib lub rhaub yuav tsum tau derated mus rau ib ncig ntawm 30 W / in² lossis tsawg dua ntawm 800℃F (427 degree) vim tias qhov kub sib txawv ntawm cov hlau thiab cov sheath tau me dua thiab cov hlau sab hauv kub tau los ze zog rau oxidation txwv sai dua. Chaw tsim tshuaj paus derating curves, uas feem ntau pom tau tias yog qhov siab tshaj W / in² piv rau qhov kub ntawm cov ntaub los yog pwm, tsis yog cov lus qhia. Lawv tau tsim los ntawm physics thiab los ntawm ntau qhov kev sim lub neej.

Rau siab -voltage 700V ib leeg- lub taub hau cartridge rhaub, uas yog siv rau hauv cov cuab yeej loj vim tias lawv siv tsawg dua tam sim no thiab yooj yim rau xaim, cov ntsiab lus ntawm watt- qhov ceev tseem zoo ib yam, tab sis qhov cuam tshuam ntawm kev ua yuam kev yog qhov phem dua. Thaum pib degradation, lub zog hluav taws xob ntau dua qhia tau tias muaj zog ntau dua los ua kom arcing, taug qab, lossis rwb thaiv tsev tawg mus. Tsawg- rwb thaiv tsev- qhov ua haujlwm tsis zoo uas tuaj yeem ua rau muaj kev cuam tshuam tsis zoo ntawm 380V tuaj yeem ua rau lub plhaub tawg lossis hluav taws kub ntawm 700V. Txoj cai dav dav yog tias yog tias koj tsis paub meej, nthuav tawm cov wattage tshaj qhov ntev rhuab ntev lossis ib txoj kab uas hla loj dua. Tsawg watt ntom ntom yuav luag feem ntau txhais tau hais tias lub neej ntev dua, qis dua ntawm qhov kub thiab txias, thiab kev zam txim rau kev teeb tsa ntau dua.

Qee cov kev cai tseem ceeb rau kev sib piv watt ntom ntom rau cov khoom siv cua sov yog: - Siv cov substrates nrog cov khoom siv hluav taws xob siab, xws li txhuas lossis tooj liab, kom tau txais qhov ntom ntom dua . - Rau cov hlau tsis muaj steel, polymers, lossis cov kua dej tuab, ua rau muaj zog heev. - Tshawb xyuas cov ntaub ntawv tsim tawm cov kua dej rau qhov kub siab tshaj plaws ntawm cov yeeb yaj kiab tuaj yeem ua kom nruj dua {3} siv cov khoom siv kom sov (0.02–0.05 mm clearance) kom tau txais kev sib cuag tau ntau tshaj plaws . - Siv thermal imaging thaum lub sij hawm commissioning kom paub tseeb tias cov sheath kub yog tib yam.

Watt ceev tsis yog ib qho parameter; nws txuas lub tshuab tso cua sov rau cov khoom siv lub peev xwm los nqa cov zis ntawd. Los ntawm ua tib zoo sib piv cov cartridge rhaub lub watt ntom ntom rau cov thermal conductivity, lub peev xwm ntawm cov cua sov, thiab cov duab ntawm qhov nruab nrab, uas tuaj yeem yog cov cuab yeej siv hlau, cov khoom siv yas, los yog cov dej da dej, cov txheej txheem tuaj yeem zam kev ua tsis tiav thaum ntxov, ua kom cov txheej txheem kub tsis tu ncua, thiab tau txais txiaj ntsig zoo tshaj plaws ntawm ob lub rhaub thiab cov khoom. Lub tshuab cua sov uas kav ntev yog ib qho uas tau tsim thiab muab tso ua ke ua haujlwm nrog nws ib puag ncig, tsis tawm tsam lawv.