Yuav ua li cas kho Cloudy los yog tsis yog - Pob tshab PET Preforms Tom Qab Txhaj Molding

Ua kom tiav Daim Ntawv Qhia Kev Lag Luam rau Siab -Kev Paub meej PET Lub raj mis ntau lawm

PET preforms pos huab los yog pos huab yog ib qho teeb meem tshwm sim hauv kev txhaj tshuaj molding, cuam tshuam ncaj qha rau qhov zoo li, pob tshab, thiab pom qhov zoo ntawm qhov kawg tshuab- cov fwj molded. Rau kev lag luam xws li tshuaj pleev ib ce, dej haus, thiab kev ntim khoom ntawm tus kheej, qhov tseeb siab tsis yog xaiv tau - nws yog qhov tseem ceeb.

Qhov teeb meem no tsis tshua muaj tshwm sim los ntawm ib qho. Hloov chaw, nws feem ntau tshwm sim los ntawm kev sib xyaw ua keraw khoom ya raws, ua tsis tau, txias efficiency, thiab cov khoom siv tej yam kev mob.

Phau ntawv qhia no muab ibhauv paus systematic-ua rau tsom xam + cov tswv yim daws teeb meemlos pab koj sai sai rov qab PET pob tshab.

1. Raw Material Issues: Moisture & Hydrolysis

Vim li cas thiaj tshwm sim

PET yog hygroscopic heev. Txawm tias luv luv raug rau huab cua tuaj yeem ua rau muaj kev nqus dej. Thaum melting, dej tawg PET molecular chains (hydrolysis), ua rau:

Txo cov viscosity hauv siab (IV)

Brittle preforms

Milky los yog foggy tsos ("dej haze")

Tej Teeb Meem

Qhuav kub tsawg dhau (<160°C)

Qhuav lub sij hawm luv luv (<4 hours)

Dryer dew point too high (>-40 degree)

Cov ntaub ntawv re- absorbs noo noo thaum lub sij hawm conveying

Kev daws teeb meem

Sivdehumidifying dryers (tsis kub cua tshuab ziab khaub ncaws)

Qhuav ntawmCi ntawm 160-165 degrees rau 4-6 teev

Xyuas kom cov dej noo<0.02% (≤50 ppm)

Khaws ciaDew point hauv qab -40 degree

Sivsealed conveying systemstiv thaiv kom tsis txhob kis kab mob

2. Txhaj Moulding Parameters: Crystallization & Stress

PET yog ib txwm amorphous tab sis tuaj yeem crystallize sai hauv qee qhov kub thiab txias. Thaum crystallization tshwm sim, pob tshab tsis tuaj yeem rov qab los.

Yam Tseem Ceeb & Kho

2.1 Tsawg Melt Kub (tsis tiav Plasticization)

Ua rau cov khoom tsis zoo → "rice-zoo li" haze
✅ Solution:

Khaws qhov kub thiab txias nyob ib puag ncig270-285 degree

2.2 Kub Melt ntau dhau (Degradation)

Ua rau yellowing, oxidation, thiab haze
✅ Solution:

Tsis txhob tshaj285-290 degree

2.3 Ntau Shear (Gate Whitening)

Kev txhaj tshuaj siab ceev → localized overheating

Tsim cov nplhaib dawb lossis pos huab ze lub rooj vag
✅ Solution:

Sivmulti-theem txhaj tshuaj (slow-ceev-slow)

Txo thawj - theem ceev yog tias lub qhov rooj vag taws tshwm

2.4 Tsis zoo Back Pressure & Ntsia Hlau Ceev

Tsawg → tsis zoo sib xyaw

Siab → overheating
✅ Solution:

Rov qab siab:8-15 bar

Screw ceev:nruab nrab (<20 m/min)

2.5 Kev Tuav Siab Ntau Tshaj (Stress Whitening)

Ua rau sab hauv kev ntxhov siab → haze tom qab demolding
✅ Solution:

Txo tuav lub zog thiab lub sijhawm

Siv lub siab yam tsawg kawg nkaus uas yuav tsum tau ua kom puv puv

3. Pwm & Txias System: Qhov Tseem Ceeb

Transparency nyob rau hauv PET nyob ntawm hnyav heevtxias ceevtiv thaiv crystallization.

Yog tias qhov txias txias tsis txaus lossis tsis sib xws, sab hauv crystallization tshwm sim - ua rau kom dawb.

Qhov Tseem Ceeb

Lub sijhawm txias txias luv dhau

Pwm kub siab dhau lawm

Tsis zoo cua txias channel tsim

Phab ntsa tuab preform

Lub qhov rooj txias tsis txaus

Kev daws teeb meem

Sivdej txias (5-15 degree)nrog siab txaus

Xyuas kom turbulent flow kom zoo dua tshav kub hloov

Ntxiv lub sijhawm txias (demolding temp<50–60°C)

Optimize pwm txias tsim (cov tub ntxhais txias yog qhov tseem ceeb)

Txo cov phab ntsa thickness yog qhov ua tau

4. Cov khoom siv & Cov teeb meem sib kis

Tej teeb meem uas tshwm sim

Hnav Ring

Ua rau cov dej ntws tsis ruaj khov thiab overheating
✅ Kho: Tshawb xyuas thiab hloov tsis tu ncua

Kub khiav kub kub tsis sib xws

Ua rau thaj tsam haze
✅ Kho:

Khaws cia240-260℃(zej zog nyob)

Xyuas cov thermocouples thiab cov cua sov

Cov khoom paug

Kev sib xyaw PET nrog PVC, PA, lossis lwm yam yas → haze
✅ Kho:

Ua tib zoo ntxuav lub thoob thaum hloov cov khoom

Pwm Condensation ("Sweating")

tshwm sim thaum pwm kub < ambient dew point

Ua rau dej cim thiab ua kom dawb
✅ Kho:

Nce pwm temp (15-20℃yog tias xav tau)

Dehumidify rhiav huab cua

Siv cov tshuab cua tshuab

5. Kev daws teeb meem ua haujlwm tau zoo

Thaum haze tshwm, ua raws cov kauj ruam no -los ntawm - cov txheej txheem kauj ruam:

Kauj Ruam 1: Tshawb xyuas cov khoom

Moisture<0.02%?

Kev ziab ntau dua lossis sib npaug li 4 teev ntawm 160 degree?

Kauj Ruam 2: Tshawb xyuas Melt Quality

Purge thiab saib melt:

Ntshiab, du → OK

npuas / ntxhib / opaque → teeb meem

Kauj Ruam 3: Txheeb xyuas qhov txias

Is preform too hot after ejection (>70 degree)?
→ Cua txias tsis txaus

Kauj Ruam 4: Txheeb xyuas Haze Pattern

Rooj vag cheeb tsam whitening → txhaj tshuaj/shear teeb meem

Tag nrho -lub cev haze → cua txias lossis cov khoom teeb meem

Kauj Ruam 5: Kho cov txheej txheem

Ua kom kub kub (+5-10 degree)

Txo kev txhaj tshuaj nrawm (tshwj xeeb tshaj yog thawj theem)

Txo tuav siab

Kauj Ruam 6: Tshawb xyuas ib puag ncig

Cov av noo siab?

Pwm condensation tam sim no?

6. Qhov tseem ceeb Takeaway

Lub hauv paus ua rau huab PET preforms ib txwm muaj feem xyuam raumolecular qauv cuam tshuam:

Hydrolysis→ rhuav tshem cov saw hlau molecular

Tsis tiav melting→ unmelted crystals

Ua kom txias txias→ crystallization

Kev Pom Zoo Kawg

Hauv kev tsim khoom tiag tiag, feem ntau cov teeb meem haze yog tshwm sim los ntawm aua ke ntawm ob yam tseem ceeb:

✔ Kev ziab tsis txaus
✔ Ua kom txias tsis txaus

Es tsis txhob kho qhov muag tsis pom, ua ke:

Txheej txheem optimization (kub, ceev, siab)

Kev tswj cov khoom siv (kom qhuav & tuav)

Thermal tswj (txias efficiency)

Ib txoj hauv kev yooj yim yuav txheeb xyuas qhov laj thawj sai sai thiab rov qab lossiab pob tshab, siab - zoo PET preforms.

Nrhiav rau customizable, siab - ntim zoo?

Hu rau peb hnub no rau kev txhawb nqa OEM / ODM.

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