Taw qhia ntawm PC yas txhaj tshuaj molding txheej txheem

PC muaj kev ua tau zoo heev, siab pob tshab, zoo cuam tshuam toughness, nkag tsis kam, thiab kub ntau yam. Lub yaj viscosity siab, cov resin yog ib qho yooj yim rau hydrolyze ntawm qhov kub thiab txias, thiab cov khoom yog yooj yim tawg. Nyob rau hauv kev saib ntawm cov yam ntxwv no, tshwj xeeb yuav tsum tau them rau cov kev kho mob sib txawv: nce lub fluidity ntawm lub yaj yog tsis tiav los ntawm kev ua kom lub siab txhaj tshuaj, tab sis los ntawm kev nce qhov kub thiab txias. Cov khiav thiab lub rooj vag ntawm cov pwm yuav tsum tau luv luv thiab tuab kom txo tau qhov siab ntawm cov kua dej, thiab tib lub sij hawm kom muaj kev txhaj tshuaj siab. Cov resin yuav tsum tau qhuav kom qhuav ua ntej molding kom nws cov dej noo tswj tau qis dua 0.02 feem pua ​​. Tsis tas li ntawd, kev ntsuas rwb thaiv tsev yuav tsum tau ua rau cov resin thaum lub sij hawm ua haujlwm los tiv thaiv cov re- nqus dej. Tsis tsuas yog yuav tsum tau tsim cov khoom tsim nyog, tab sis kuj muaj qhov tseeb ntawm cov txheej txheem molding, xws li nce pwm kub thiab tom qab- ua cov khoom, tuaj yeem txo lossis tshem tawm kev ntxhov siab sab hauv. Kho cov txheej txheem tsis raws sij hawm nyob ntawm qhov sib txawv ntawm cov khoom.

Cov yam ntxwv ntawm PC: PC muaj viscosity siab, kub yaj, thiab dej tsis zoo. Hauv qhov no, nws yuav tsum tau txhaj tshuaj ntawm qhov kub siab dua (270-320 ° C). Hais txog kev hais lus, cov khoom siv kub hloov pauv yog nqaim, thiab kev ua haujlwm tsis zoo li PMMA. Kev txhaj tshuaj siab tsis tshua muaj txiaj ntsig ntawm qhov fluidity, tab sis vim qhov loj viscosity, qhov kev txhaj tshuaj siab tseem loj heev. Ua ke, txhawm rau tiv thaiv kev ntxhov siab sab hauv, lub sijhawm tuav lub sijhawm yuav tsum luv li sai tau. Lub shrinkage tus nqi yog qhov loj thiab qhov loj yog qhov ruaj khov, tab sis qhov kev ntxhov siab sab hauv ntawm cov khoom yog loj thiab nws yooj yim rau tawg. Yog li ntawd, nws yog ib qho tsim nyog yuav tsum ua kom qhov kub thiab txias es tsis txhob siv lub siab los txhim kho qhov fluidity, thiab nce pwm kub, txhim kho pwm qauv, thiab tom qab kev kho mob kom txo tau qhov tawg. Thaum qhov kev txhaj tshuaj nrawm qis, qhov tsis xws li ripples yuav tshwm sim ntawm lub rooj vag. Qhov kub ntawm lub nozzle yuav tsum tau tswj nyias, qhov pwm kub yuav tsum siab, thiab qhov kev tiv thaiv ntawm cov khiav thiab lub rooj vag yuav tsum me me.
PC txhaj tshuaj molding kev ua tau zoo: PC yog cov yas crystalline nrog qhov pom tseeb melting point. Nws melts ntawm 220 degree thiab decomposes ntawm 350 degree; Qhov kev ua haujlwm dav dav yog 250-320 degree; nws nqus dej, thiab cov dej me me tuaj yeem ua rau nws decompose ntawm qhov kub thiab txias. Thaum lub sij hawm txhaj tshuaj molding, nws yuav tsum tau qhuav, thiab ziab kom qhuav yuav siv tau ntawm 120 degree rau 4 mus rau 5 teev; Lub yaj viscosity ntawm cov khoom siv PC yog qhov loj, thiab yuav tsum muaj siab ntau dua thaum txhaj tshuaj molding; Thaum lub sijhawm ua haujlwm PC, yog tias muaj kev tso cai, pwm kub tuaj yeem nce ntxiv nrog lub tshuab pwm kub kom txo cov khoom
If it is a product with inserts, the diameter of the inserts is less than 1-2mm, and preheating may not be considered. For larger inserts, preheating should be considered, otherwise, stress cracking will occur; PC shrinkage rate and processing conditions Regardless of the wall thickness of the product, its longitudinal and transverse shrinkage rates are relatively close, so it can be processed into products with high precision; its shrinkage rate is 5‰, and the overflow value is 0.05mm.


(1) Kev txhaj tshuaj kub
Cov duab, qhov loj me, pwm qauv, cov khoom ua tau zoo, cov kev xav tau, thiab lwm yam ntawm cov khoom yuav tsum tau txiav txim siab tom qab kev txiav txim siab.
ua. Feem ntau, qhov kub siv hauv molding yog nyob nruab nrab ntawm 270 thiab 320 degree. Thaum cov khoom kub siab dhau, xws li tshaj 340 degree, PC
Decomposition yuav tshwm sim, cov xim ntawm cov khoom yuav darker, thiab tsis xws luag xws li nyiaj threads, tsaus kab txaij, dub me ntsis, thiab npuas yuav tshwm nyob rau saum npoo.
Qhov kev ua tau zoo kuj poob qis heev.


(2) Txhaj tshuaj
Nws muaj qee yam cuam tshuam rau lub cev thiab cov khoom siv kho tshuab, kev ntxhov siab sab hauv, thiab molding shrinkage tus nqi ntawm cov khoom PC, thiab muaj kev cuam tshuam ntau dua rau cov tsos thiab pwm tso tawm ntawm cov khoom. Tsawg heev los yog siab heev txhaj tshuaj yuav ua rau tej yam tsis xws luag nyob rau hauv cov khoom. Feem ntau, kev txhaj tshuaj siab yog tswj ntawm 80 thiab 120MPa. Rau cov khoom siv nrog cov phab ntsa nyias, cov txheej txheem ntev, cov duab nyuaj, thiab cov rooj vag me me, txhawm rau kom kov yeej qhov kev tawm tsam ntawm cov yaj ntws, yog li txawm tias cov kab noj hniav puv, qhov kev txhaj tshuaj ntau dua (120 145MPa) kom tau txais kev ua tiav thiab du. khoom nto.


(3) Tuav siab thiab tuav lub sijhawm
Qhov loj ntawm kev tuav lub siab thiab qhov ntev ntawm lub sijhawm tuav muaj kev cuam tshuam zoo rau kev ntxhov siab sab hauv ntawm cov khoom PC. Nws yog ib qho yooj yim los tsim kom muaj kev ntxhov siab loj nyob ib ncig ntawm lub rooj vag. Hauv kev ua haujlwm tiag tiag, nws feem ntau daws tau los ntawm cov txheej txheem ntawm cov khoom siv kub thiab tsis tshua muaj siab. Kev xaiv ntawm lub sijhawm tuav yuav tsum nyob ntawm qhov tuab,
Nws nyob ntawm lub rooj vag loj thiab pwm kub. Feem ntau, cov khoom me me thiab nyias tsis xav tau lub sijhawm tuav lub sijhawm ntev; ntawm qhov tsis sib xws, cov khoom loj thiab tuab yuav tsum muaj lub sijhawm tuav lub sijhawm ntev. Qhov ntev ntawm lub sijhawm tuav tuaj yeem txiav txim siab los ntawm kev ntsuas lub sijhawm ntawm lub rooj sib khi.


(4) Txhaj ceev
Nws tsis muaj txiaj ntsig zoo rau kev ua haujlwm ntawm cov khoom siv PC. Tsuas yog nyias -walled, me rooj vag, tob- qhov, thiab ntev- cov khoom ua haujlwm, a
Feem ntau siv qhov nruab nrab ceev los yog qeeb qeeb, zoo dua ntau-theem txhaj tshuaj, feem ntau siv qeeb- nrawm- qeeb ntau- theem txhaj tshuaj.

(5) Pwm kub
Feem ntau, nws tuaj yeem tswj tau ntawm 80 txog 100 degree. Rau cov khoom uas muaj cov duab tsis yooj yim, cov khoom nyias nyias, thiab cov kev xav tau siab dua, nws tuaj yeem nce mus rau 100 txog 120 degree, tab sis nws tsis tuaj yeem tshaj qhov kub deformation ntawm pwm.

(6) Screw ceev thiab backpressure
Vim lub siab viscosity ntawm PC yaj, nws yog qhov zoo rau kev saib xyuas ntawm cov yas yas, tso pa tawm, thiab kev txhaj tshuaj molding tshuab, tiv thaiv cov ntsia hlau los ntawm overloaded, thiab qhov ceev ntawm cov ntsia hlau yuav tsum tsis txhob siab dhau. Nws raug nquahu kom tswj lub siab ntawm 10 feem pua ​​​​thiab 15 feem pua ​​​​ntawm kev txhaj tshuaj.

(7) Tso tus neeg sawv cev
Hauv kev txhaj tshuaj molding txheej txheem ntawm PC, kev siv cov pwm tso tawm cov neeg ua haujlwm yuav tsum tau tswj nruj me ntsis, thiab kev siv cov khoom siv rov ua dua yuav tsum tsis pub tshaj peb zaug, thiab cov nyiaj siv yuav tsum yog li 20 feem pua.

(8) Yuav tsum muaj cov tshuab yas rau kev tsim cov khoom PC
Nws yuav tsum tau hais tias qhov siab tshaj plaws txhaj tshuaj ntim ntawm cov khoom (xws li khiav, rooj vag, thiab lwm yam) yuav tsum tsis txhob ntau tshaj 70 feem pua ​​​​rau 80 feem pua ​​ntawm cov nominal txhaj ntim, thiab ib tug gradient compression ntsia hlau nrog ib tug - taub hau xov nrog sib npaug pitch thiab tsis yog -ntiv nplhaib rov qab yog siv. Qhov ntev - txoj kab uas hla ntawm cov ntsia hlau L / D yog 15-20, thiab qhov sib xyaw compression piv C / R yog 2-3.