Txoj Cai Ua Haujlwm ntawm LDPE Blown Film Machine
LDPE (Low-Density Polyethylene) tshuab tshuab tshuab ua cov yas pellets rau hauv cov yeeb yaj kiab los ntawm extrusion, tshuab, txias, thiab winding. Nws txoj hauv kev ua haujlwm tseem ceeb tuaj yeem muab faib ua cov kauj ruam hauv qab no:
1. Raw Material Pre-kev kho mob
LDPE pellets (los yog sib tov nrog masterbatches / additives) tau ziab (yog tias cov ntsiab lus noo noo siab) ntawm lub tshuab ziab khaub ncaws (60-80 degree). Qhov no tiv thaiv npuas los ntawm vaporized ya raws thaum extrusion, kom ntseeg tau tias zaj duab xis zoo.
2. Extrusion & Plasticizing (Core kauj ruam)
Khoom siv: Ib - ntsia hlau extruder (ntsia hlau, chim, tso cua sov).
Cov pellets nkag mus rau hauv extruder los ntawm lub hopper thiab txav mus rau qhov tuag ntawm cov ntsia hlau tig. Peb theem tshwm sim:
Pub Zone:Cov pellets yog conveyed thiab pib compacted.
Compression Zone:Screw channel qhov tob txo qis, compressing cov ntaub ntawv thiab tsim cov cua sov shear (pab los ntawm cov cua kub chim). LDPE softens thiab melts.
Metering Zone:Molten LDPE yog homogenized, tsim kom ruaj khov yaj uas ntws mus rau qhov tuag ntawm qhov siab thiab tso zis tas li.
3. Tuag Moulding
Khoom siv:Annular tuag (kauv los yog mandrel hom).
Molten LDPE nkag mus rau hauv qhov tuag thiab ntws los ntawm ib qho annular channel (tuag qhov sib txawv: 0.5-2 hli), extruding uniformly tsim ib tug tubular parison (unblown zaj duab xis precursor). Tuag tsim kom zoo ib yam txaus kom tsis txhob thickness sib txawv.
4. Tshuab & Haul-tawm
Qhov tseem ceeb Parameter: Blow-up Ratio (BUR: npuas txoj kab uas hla / tuag txoj kab uas hla, feem ntau 1.5–4:1); Draw Ratio (haul-tawm ceev/extrusion ceev, txiav txim siab ntev stretch).
Tshuab:Compressed cua inflates lub parison mus rau hauv ib tug npuas (ntev txoj kab uas hla), stretching LDPE molecules transversely (radially) los txhim kho transverse zog.
Haul- tawm:Nip rollers rub lub npuas nce. Tus qauv kos duab tswj cov kab ntev ntev, cuam tshuam rau lub zog ntev thiab tuab (siab dua piv=zaj duab xis thinner).
5. Txias & Shaping
Khoom siv:Cua nplhaib (sab nraud txias) + cua txias sab hauv (yeem).
Cov npuas kub (160-200 degree) yog txias sai heev los ntawm 360℃airflow los ntawm lub nplhaib cua mus rau hauv qab LDPE lub iav hloov kub (~ 80-100 degree), solidifying nws cov duab. Cov kiv cua sab hauv lossis dej txias tuaj yeem ua kom zoo dua.
6. Winding & Post-kev ua haujlwm
Cov npuas dej txias dhau los ntawm kev sib tsoo thav duab (flattening), thickness gauges, thiab raug mob rau hauv niam yob los ntawm winders. Niam rolls raug txiav rau hauv cov yeeb yaj kiab tiav rau kev luam ntawv, hnab - ua, thiab lwm yam.
Ntsiab Parameters & Impacts
Kev tswj qhov kub thiab txias: Zones (Feeding: 150–180°C; Compression: 170–200°C; Metering: 180–220°C) must avoid degradation (>250 degree) los yog tsis sib xws.
BUR & Draw Ratio:Txiav txim siab thickness, lub zog (biaxial stretching txhim kho mechanics), thiab pob tshab (stretching refines crystals).
Ua kom txias txias:Kev ua kom txias tsis txaus ua rau muaj qhov sib txawv / tuab; dhau - txias ua rau muaj kev ntxhov siab, txo qhov tawv.
Cov ntsiab lus
Lub tshuab LDPE tshuab tshuab tsis tu ncua hloov pellets rau hauv biaxially stretched films ntawm "extrusion → tuag molding → tshuab/haul-tawm → txias → winding." Nws leverages ntsia hlau extrusion, tshuab, thiab traction rau tailor film thickness, lub zog, thiab optics rau ntim, ua liaj ua teb, thiab kev lag luam.
