Qhov txawv ntawm PET thiab PETG yog dab tsi?

Tus tsiaj, ib qho polycondensate, feem ntau yog siv rau hauv cov yeeb yaj kiab ntim khoom noj thiab cov ntaub textile, ntawm lwm yam kev siv. Tam sim no nws tau siv ntau dua los ua cov khoom ntim khoom, tsis yog tsuas yog hauv cov fwj dej qab zib xwb, tab sis kuj tseem siv rau hauv amorphous PET (APET), crystalline PET (CPET) cov kaus poom thiab cov phaj. Hauv tsib xyoos dhau los, engineering-grade PET thiab copolyesters, ua cov khoom polymer tshiab, tau siv rau hauv engineering thiab cov ntaub ntawv ntim khoom tshwj xeeb, raws li.
Qhov ua tiav ntawm PET hauv kev ntim dej qab zib yog vim nws qhov tawv thiab pob tshab, muaj peev xwm taw qhia, muaj txiaj ntsig zoo rau kev lag luam, thiab kev txhim kho cov thev naus laus zis ua lub raj mis ceev ceev. Cov kaus poom dej haus PET yog lub teeb yuag, tsis tawg, siv tau dua, thiab muaj cua zoo. Lub raj mis dej haus PET 2-liter puv yog sib dua 24% dua li lub raj mis iav zoo sib xws; lub raj mis khoob hnyav 1/10 ntawm lub raj mis iav ntawm tib qhov loj me. Qhov no txuag cov neeg ua haujlwm, lub zog, thiab cov nqi hauv txhua qhov txuas los ntawm cov chaw tsim khoom mus rau cov neeg siv khoom.
Tshuaj lom neeg thiab cov khoom

PET rau cov fwj dej haus yog tsim los ntawm terephthalic acid (TPA) tau los ntawm kev oxidation ntawm p-xylene. Terephthalic acid yog purified lossis reacted nrog methanol los tsim dimethyl terephthalate (DMT), lossis ntxiv oxidized los tsim pure terephthalic acid (PTA). Lwm cov khoom siv raw rau PET yog ethane, uas hloov mus rau ethylene glycol (EG) los ntawm kev ua haujlwm. PET yog cov polymer condensation tsim los ntawm kev sib txuas ntxiv polymerization ntawm DMT (lossis PTA) thiab EG hauv lub xeev molten, thiab tom qab ntawd cov txheej txheem polymerization khov-xeev kom tau txais cov siv lead ua loj thiab qhov hnyav molecular kawg thiab viscosity intrinsic. Cov txheej txheem khov-xeev kuj ua rau cov ntsiab lus ethanol ntawm cov polymer qis txaus.

Cov tshuaj PET ua lag luam dav dav yaj ntawm li 480F (), tab sis qhov chaw yaj ntawm cov PET crystalline siab yog li 520F ().

PET crystallized uas tau teeb tsa rau ntawm lub cev muaj zog heev. Nws ruaj khov thiab pom tseeb, thiab tiv taus cov kua qaub tsis muaj zog, cov hauv paus thiab ntau cov kuab tshuaj.

Cov qib tshwj xeeb

Qib PET uas ncab tau tuaj yeem muab cov xim khov kho, xim ntsuab thiab daj daj me ntsis. Cov polymer xim hauv lub reactor tsis tas yuav tsum tau sib xyaw nrog cov teebmeem tsis zoo rau cov khoom siv lub cev, thiab txhim kho cov xim sib xws. Cov resins ntshiab ntawm ntau yam viscosities intrinsic muaj. PET copolymers crystallize qeeb qeeb, uas tso cai rau lawv tsim cov fwj dej qab zib zoo dua ntau yam kev ua haujlwm. Ib qho extrusion blow moldable polymer kuj muaj. Cov khoom siv no ua ke cov txiaj ntsig ntawm lub zog yaj zoo thiab qeeb crystallization, thiab tuaj yeem ua tiav yooj yim ntawm cov khoom siv extrusion blow molding tsim nyog. Ntau yam reinforced, flame retardant thiab lwm yam polymers tshwj xeeb yeej ib txwm raug qhia lossis hloov kho kom tau raws li cov ntawv thov tshiab.

PETGcopolyester yog lwm qhov piv txwv ntawm ntau tus copolyesters. Tsis zoo li PCTA, uas tau hloov kho nrog kua qaub, PETG yog diol-modified polymer ua los ntawm kev sib xyaw CHDM diol nrog TPA (terephthalic acid) thiab ethylene glycol. PETG copolymers tuaj yeem ua pwm lossis extruded thiab feem ntau tseem nyob amorphous, pob tshab thiab tsis muaj xim, txawm tias nyob rau hauv cov ntu loj.

Nws muaj qhov ruaj khov, tawv thiab zoo toughness, txawm tias nyob rau hauv qhov kub qis. Kev sib xyaw ua ke ntawm pob tshab, toughness thiab lub zog yaj ua rau nws muaj txiaj ntsig zoo rau kev txhaj tshuaj molding, tshuab molding thiab extrusion ntawm profiles, kav dej, zaj duab xis thiab daim ntawv. PETG muaj nyob rau hauv daim ntawv tsis hloov pauv lossis nrog ntau yam additives, suav nrog cov neeg sawv cev tso tawm, masterbatches, thiab impact modifiers rau kev txhaj tshuaj molding.

PETG yuav tsum tau qhuav ntawm 120-160F li 4-6 teev ua ntej molding lossis extrusion. Hauv ob qho txheej txheem, qhov kub yaj yog txij li 420F txog 510F. Lub sijhawm tuav ntawm cov khoom siv ua haujlwm ntawm qhov kub siab dua yuav tsum luv li sai tau kom tiv thaiv kev puas tsuaj ntau dhau. Kev txhaj tshuaj molding yuav tsum tau ua rau ntawm lub tshuab txhaj tshuaj molding, xav kom txhua qhov txhaj tshuaj yuav tsum yog 50% txog 80% ntawm nws lub peev xwm.

PETG tuaj yeem raug extruded thiab blow molded ntawm qhov kub yaj ntawm 400-450F los ua lub raj mis pob tshab rau cov tshuaj zawv plaub hau, cov tshuaj ntxuav tes, cov khoom siv tu cev, cov roj av, thiab cov khoom ntim khoom noj. Cov khoom siv no ua tau raws li FDA cov qauv rau kev sib cuag nrog zaub mov.

Kev rho tawm tuaj yeem tsim ntau yam profiles, nrog rau cov raj ntim khoom, zaj duab xis, thiab cov ntawv, suav nrog cov khoom siv kho mob. PETG thiab PCTA tuaj yeem raug sterilized nrog ethylene oxide thiab Y rays.

Thaum siv rau kev txhaj tshuaj molding, PETG feem ntau yog ua tiav ntawm qhov kub yaj ntawm 450-510F, nrog rau qhov kub pwm ntawm li 70-130F. Cov ntawv thov tam sim no suav nrog cov ntaub thaiv cov cuab yeej, cov ntaub thaiv tshuab, cov thawv kom zoo nkauj, cov taw qhia ntawm cov cuab yeej siv, cov khoom tso saib thiab cov khoom ua si.

PET feem ntau yog siv rau hauv cov dej qab zib thiab cov dej qab zib ntim. PET muaj ze li ntawm 100% ntawm kev lag luam thawv ntim 2-liter uas tsis siv tau dua, thiab 1.5-liter, 1-liter, 0.5-liter thiab cov fwj PET me dua kuj tau lees paub dav.

PET siv rau hauv cov khoom noj, cawv, thiab cov tshuaj ntxuav tes. Kev thov PET yuav txuas ntxiv mus rau kev loj hlob rau cov dej haus tsis muaj carbonated thiab cov khoom ntim khoom lag luam. Cov khoom noj ntim suav nrog mustard, cov khoom siv roj hmab, txiv laum huab xeeb, cov khoom qab zib, cov roj ua noj, cov dej qab zib thiab cov kua txiv hmab txiv ntoo concentrated. Cov xim tshiab, tshwj xeeb tshaj yog cov xim Weber, yog nrov hauv kev ntim cov tshuaj, cov vitamins thiab cov tshuaj ntxuav tes.

Ib qho ntawm cov ntawv thov tshiab thiab loj hlob sai tshaj plaws rau cov thawv PET yog cov khoom noj lossis dej haus ntim, uas yuav tsum tau ntim rau qhov kub siab. Ntau yam khoom noj, tshwj xeeb tshaj yog txiv hmab txiv ntoo lossis khoom noj lossis dej haus uas muaj txiv hmab txiv ntoo ntau, yuav tsum tau ntim rau ntawm 180F lossis siab dua. Qhov no muab kev ua kom tsis muaj menyuam (sterilization) ntawm cov khoom thiab lub thawv thaum lub sijhawm ntim. Cov thawv ib txwm muaj, xws li cov hnab rau dej qab zib thiab dej qab zib, feem ntau yuav ntsws thiab deform thaum raug qhov kub siab tshaj 160F, uas yog vim muaj kev txo qis kev ntxhov siab. Kev ntxhov siab concentration yog tsim thaum lub sijhawm ncab tshuab molding ntawm lub thawv. Technology tau tsim los txhim kho kev tiv thaiv cua sov thaum lub sijhawm ua, feem ntau hu ua "kev teeb tsa cua sov" technology. Nyob ntawm cov txheej txheem ua haujlwm tshwj xeeb, muaj ntau cov ntsiab lus ntawm cov txheej txheem ua haujlwm, uas yog proprietary heev, raws li cov thawv uas haum rau kev ntim ntawm 190-195F tuaj yeem tsim tau. Cov khoom uas xav tau ntim nrog cov yam ntxwv no suav nrog cov kua txiv hmab txiv ntoo ntshiab. Cov dej haus muaj kua txiv hmab txiv ntoo ntau, tshuaj yej, qee yam isotonic thiab dej haus kis las, condiments, kua txiv hmab txiv ntoo concentrated thiab qee yam dej ntxhia.

Lwm yam kev siv kawg ntawm PET yog siv dav hauv kev txheej extrusion thiab extrusion zaj duab xis thiab daim ntawv. PET yog siv los ua cov khoom siv txheej extrusion rau cov ntawv ntim khoom siv hauv qhov cub. Tsis tas li ntawd, crystalline PET (CPET) tuaj yeem siv los ua cov khoom siv yooj yim los ua cov tais qhov cub.

Feem ntau cov zaj duab xis PET yog biaxially oriented thiab siv ua X-ray thiab lwm yam zaj duab xis duab, nqaij thiab cheese ntim, magnetic tapes, hluav taws xob rwb thaiv tsev, luam ntawv phaj thiab lub raj mis ntim hnab. PET kuj tseem siv ua cov ntaub ntawv rau kev lag luam. Cov zaj duab xis thiab daim ntawv PET uas tsis yog crystalline, tsis muaj oriented tab tom pib siv rau kev tsim cov thawv, tais, cov khoom ua npuas ncauj thiab khob dej haus.

Kev xaus lus: PETG yog ib qho kev hloov kho dua tshiab ntawm PET, nrog rau kev pom tseeb dua, kev tawv dua, kev cuam tshuam zoo dua, thiab tau kawg tus nqi siab dua.