Kev siv cov ntawv polypropylene (PP) rau cov khoom siv hauv tsev tau dhau los ua qauv kev xaiv hauv kev lag luam, uas tau tsav los ntawm cov khoom siv tshwj xeeb ntawm lub cev thiab tshuaj lom neeg. Raws li semi-crystalline polymer, polypropylene cov yam ntxwv tseem ceeb ntawm kev ua tau zoo yog txiav txim siab los ntawm nws cov qauv saw molecular. Kev tsim khoom muaj ntau dua li kev hloov pauv yooj yim ntawm cov khoom siv raw rau hauv daim ntawv; Nws yog cov txheej txheem uas tso siab rau kev tswj hwm ntawm cov thermodynamic thiab rheological tej yam kev mob kom ua tiav qhov kev txiav txim thiab stabilization ntawm polymer molecular chains.
Cov txheej txheem pib nrog cov khoom siv raw nkag mus rau hauv lub cev, feem ntau yog homopolymer lossis copolymer granules. Ntau dua li tam sim ntawd melting tam sim ntawd, cov granules no tau raug kev kho mob nruj heev -xws li ziab thiab homogenization- kom tshem tawm cov kab ya raws thiab txo cov batch - mus rau - batch kev ua tau zoo variations. Qhov pretreatment theem no yog qhov tseem ceeb rau kev ruaj ntseg ntawm kev ua haujlwm tom ntej; lub xub ntiag ntawm noo noo tuaj yeem ua rau hydrolysis ntawm qhov kub thiab txias, ua rau molecular saw scission thiab ncaj qha cuam tshuam lub zog txhua yam ntawm daim ntawv kawg.
Thaum nkag mus rau theem extrusion, cov txheej txheem yog nyob rau hauv cov kev cai ntawm cov yaj ntws tus cwj pwm. Lub extruder plasticizes cov khoom siv thiab tsim cov cua sov los ntawm kev sib hloov ntawm cov ntsia hlau, yuav tsum muaj kev sib koom tes tswj xyuas qhov kub thiab txias, ntsia hlau ceev, thiab cov nqi shear. Cov shear ntau dhau tuaj yeem ua rau polymer degradation, thaum qhov kub tsis txaus tiv thaiv kom tsis muaj melting thiab sib tov. Additives xws li antioxidants, lub teeb stabilizers, los yog nplaim retardants yuav raug qhia nyob rau theem no; lawv compatibility nrog polypropylene matrix thiab cov uniformity ntawm lawv dispersion ncaj qha cuam tshuam rau daim ntawv ntev -lub sij hawm durability thiab kev nyab xeeb ua raws.
Sheet shaping cia siab rau qhov txias txias thiab thauj - tawm tshuab. Qhov siab - kub yaj extruded los ntawm qhov tuag thawj zaug dhau los ntawm peb - yob calender pawg, qhov twg yob qhov kub, qhov sib piv ceev, thiab qhov sib txawv qhov chaw ua haujlwm tseem ceeb rau kev tswj cov ntawv tuab, gloss, thiab nto flatness. Thaum cov cua txias ceev boosts ntau lawm efficiency, nws yuav ua rau imperfect crystallization thiab tsim cov kev ntxhov siab nyob rau hauv, tsim kom muaj kev pheej hmoo ntawm deformation thaum lub sij hawm tom ntej thermoforming los yog kawg - siv. Cov nqi cua txias yuav tsum tau sib phim rau cov polymer cov crystallization kinetics kom muaj kev sib npaug ntawm qhov seem stability thiab microstructural kev ncaj ncees.
Thaum tsim, daim ntawv mus rau winding los yog txiav - mus rau - ntev theem. Nyob rau theem no, nws yog ib qho tseem ceeb uas yuav tsum tswj kom tsim nyog nro thiab winding speeds los tiv thaiv daim ntawv ntawm wrinkling los yog undergoing tensile deformation. Rau cov nplooj ntawv tom qab siv nyob rau hauv lub thermoforming ntawm cov khoom vaj tse, cov ntug kev sib dhos ntawm cov kauj thiab cov uniformity ntawm sab hauv kev ntxhov siab cuam tshuam ncaj qha pub noj precision thiab cov txiaj ntsig ntawm cov khoom stamped ntawm cov kab ntau lawm.
Kev tsom xam ntawm tag nrho cov kab ntau lawm nyob rau hauv kev tswj tus cwj pwm ntawm polypropylene thaum lub sij hawm hloov theem. Nws tus nqi yog nyob rau hauv kev hloov pauv cov ntaub ntawv polymer rau hauv cov khoom nruab nrab nrog cov khoom zoo ib yam thiab txhim khu kev qha ua tiav los ntawm kev sib koom ua ke ntawm qhov ntsuas qhov ntsuas. Thaum kawg, kev tsim thiab kev tswj hwm ntawm cov kab ntau lawm sawv cev rau kev siv tswv yim thiab kev siv engineering ntawm cov ntaub ntawv tshawb fawb hauv kev lag luam txuas ntxiv.