Txhawm rau nkag siab txog kev tsim pwm, nws yog ib qho tseem ceeb kom nkag siab txog cov khoom siv ntawm PET, vim tias pwm yog cov cuab yeej "tsim- ua" rau cov khoom siv no.
Crystallization thiab Temperature Sensitivity: PET yog ib nrab -crystalline polymer. Cov cua txias thaum lub sij hawm molding ncaj qha cuam tshuam rau lub pob tshab, qhov ruaj khov, thiab cov khoom siv kho tshuab ntawm cov khoom tiav. Kev ua kom txias sai yog qhov zoo rau kev tau txais cov khoom pob tshab amorphous; qeeb cua txias txhawb nqa crystallization, ua rau cov khoom siv dawb thiab ntau dua, tab sis tuaj yeem txhim kho rigidity thiab kub tsis kam. Ntau hom pwm cua txias tsim tsim kom muaj kev tswj xyuas qhov kub thiab txias.
Hygroscopicity: PET raw cov ntaub ntawv nqus dej noo los ntawm huab cua thaum khaws cia. PET uas muaj cov kab dej noo tau dhau los ua hydrolysis thaum lub sijhawm siab -kub txhaj tshuaj molding, ua rau cov saw hlau molecular tawg, ua rau cov khoom nkig thiab txo nws lub zog. Pwm tsim yuav tsum xav txog kev sib raug zoo nrog cov hoppers kom qhuav thiab txo cov khoom ntws stagnation nyob rau hauv lub khiav tsim los tiv thaiv lub zos overheating thiab degradation.
Shrinkage Rate: PET's molding shrinkage tus nqi yog qhov ruaj khov tab sis tsis yog xoom, thiab muaj qhov sib txawv ntawm qhov ntev (ntws kev taw qhia) thiab tus nqi hloov pauv (anisotropy). Kev xam kom raug thiab kev them nyiaj ntawm tus nqi shrinkage yog qhov yuav tsum tau ua ua ntej kom ntseeg tau tias cov khoom seem raug.
High viscosity thiab rheological zog: Molten PET muaj viscosity siab. Qhov no yuav tsum muaj kev sib txawv thiab kev sib tw khiav hauv cov pwm, tsis txhob muaj cov kaum ntse ntse kom txo tau cov dej ntws tawm, ua kom tiav puv, thiab txo qis kev ntxhov siab.
