Muaj ntau hom ntawv yas nrog ntau yam kev siv. Tam sim no, cov hom tseem ceeb yog polyvinyl chloride, polystyrene thiab polyester (PET). PET daim ntawv muaj kev ua tau zoo thiab ua tau raws li lub teb chaws kev noj qab haus huv Performance index cov cai rau cov khoom molded thiab thoob ntiaj teb kev tiv thaiv ib puag ncig. Lawv nyob rau lub rooj tiv thaiv ib puag ncig. Tam sim no, kev ntim khoom yuav tsum tau ua kom tau raws li kev tiv thaiv ib puag ncig thiab rov ua dua tshiab, yog li qhov kev thov rau cov ntawv PET tau nce siab dua. Kab lus no feem ntau tham txog cov txheej txheem tsim khoom thiab cov teeb meem tshwm sim ntawm PET nplooj ntawv.
PET daim ntawv ntau lawm technology:
(1) PET daim ntawv
Zoo li lwm yam yas, cov khoom ntawm PET daim ntawv yog ze ze rau qhov hnyav molecular. Molecular hnyav yog txiav txim los ntawm intrinsic viscosity. Qhov siab dua qhov viscosity ntawm lub cev, qhov zoo ntawm lub cev thiab cov khoom siv tshuaj, tab sis qhov tsis zoo fluidity thiab nyuaj rau kev tsim. Qhov qis dua qhov viscosity ntawm lub cev, qhov ua rau lub cev thiab tshuaj lom neeg tsis zoo thiab cuam tshuam lub zog. Yog li, qhov viscosity ntawm tus tsiaj ntawv yuav tsum yog 0.8dl / g-0.9dl / g.
(2) Cov txheej txheem ntau lawm ntws
Lub ntsiabCov khoom siv tsim khoom rau cov ntawv PETsuav nrog crystallization yees, ziab yees, extruders, tuag hau, peb-yob calenders thiab coilers. Cov txheej txheem ntau lawm yog: raw khoom crystallization-drying-extrusion plasticization-extrusion molding-calendering thiab shaping-winding khoom.
1. Crystallization. Cov PET cov hlais yog rhuab thiab crystallized nyob rau hauv lub crystallization ntauwd kom haum cov molecules, thiab ces nce lub iav hloov kub ntawm lub slices kom tsis txhob adhesion thiab clogging ntawm lub hopper thaum lub sij hawm qhuav txheej txheem. Crystallization feem ntau yog ib kauj ruam tseem ceeb. Crystallization yuav siv sij hawm 30-90 feeb thiab qhov kub ntawm qis dua 149 ° C.
2. Qhuav. Thaum qhov kub thiab txias, dej yuav hydrolyze thiab degrade PET, ua rau txo qis ntawm nws cov yam ntxwv adhesion, thiab nws lub cev muaj zog, tshwj xeeb tshaj yog cuam tshuam lub zog, yuav txo qis thaum molecular hnyav. Yog li ntawd, ua ntej melting thiab extruding, PET yuav tsum tau qhuav kom txo cov dej noo, uas yuav tsum tsawg tshaj li 0.005%. Dehumidification tshuab yog siv rau ziab. Vim yog hygroscopicity ntawm PET cov ntaub ntawv, thaum dej nkag mus tob rau hauv qhov chaw ntawm daim hlais, molecular bonds yuav tsim, thiab lwm qhov ntawm cov dej yuav nkag mus tob rau hauv cov hlais, ua kom qhuav nyuaj. Yog li ntawd, huab cua kub zoo tib yam siv tsis tau. Cov cua kub dej dew taw tes yuav tsum qis dua -40C, thiab cua kub nkag mus rau hauv lub tshuab ziab khaub ncaws los ntawm kev kaw lub voj voog kom qhuav tas mus li.
3. Nyem. Tom qab crystallization thiab ziab, PET yog hloov mus rau hauv ib lub polymer nrog ib qho pom tseeb melting point. Lub polymer molding kub yog siab thiab kev tswj qhov kub thiab txias yog nqaim. Polyester tshwj xeeb barrier ntsia hlau yog siv los cais cov unmelted hais los ntawm cov yaj, uas yuav pab txhawb nqa ib tug ntev shear txheej txheem thiab ua rau kom cov zis ntawm extruder. Adopts saj zawg zog di ncauj tuag nrog streamlined throttle pas nrig. Lub taub hau pwm yog tapered. Streamlined runners thiab kos-dawb tuag daim di ncauj qhia tias qhov ua tiav yuav tsum zoo. Lub tshuab cua kub pwm muaj cov dej ntws tawm thiab kev ua haujlwm huv.
4.Cooling thiab shaping. Tom qab cov yaj tawm ntawm lub taub hau, nws ncaj qha nkag mus rau peb-yob calender rau calendering thiab txias. Qhov kev ncua deb ntawm peb-roller calender thiab lub taub hau tshuab yog feem ntau khaws cia ntawm li 8cm, vim hais tias yog tias qhov kev ncua deb loj dhau lawm, lub rooj tsavxwm yuav yooj yim sag thiab wrinkle, ua rau tsis zoo. Tsis tas li ntawd, vim qhov kev ncua deb, cov cua sov dissipation thiab txias yog qeeb, thiab cov siv lead ua tig dawb, uas tsis yog qhov zoo rau dov. Peb-roller calendering unit muaj xws li sab sauv, nruab nrab thiab qis rollers. Cov ncej ntawm cov menyuam nruab nrab yog tsau. Thaum lub sij hawm txias thiab calendering txheej txheem, cov menyuam nto kub yog 40 ° c-50c. Cov ncej ntawm cov yob sab saud thiab qis tuaj yeem txav mus los.
Post lub sij hawm: Sep-28-2023
