Acrylic txhaj tshuaj molding txheej txheem
Cov tshuaj npe ntawm acrylic yog polymethyl methacrylate (PMMA luv luv). Vim qhov tsis zoo ntawm PMMA qhov tawv tawv tsis siab, yooj yim rau rub cov plaub hau, tsis muaj kev cuam tshuam tsis zoo, tsis zoo molding fluidity thiab lwm yam tsis zoo, kev hloov kho ntawm PMMA tau tshwm sim ib zaug. Xws li copolymerization ntawm methyl methacrylate thiab styrene, butadiene, kev sib xyaw ntawm PMMA thiab PC, thiab lwm yam.
Lub fluidity ntawm PMMA yog phem dua li ntawm PS thiab ABS, thiab cov yaj viscosity yog rhiab heev rau qhov kub thiab txias. Thaum lub sij hawm molding txheej txheem, cov yaj viscosity feem ntau yog hloov los ntawm kev txhaj tshuaj kub. PMMA yog amorphous polymer nrog melting kub siab tshaj 160 degree thiab decomposition kub ntawm 270 degree.
1. Kev tuav cov yas
PMMA muaj qee qhov kev nqus dej, thiab nws cov dej nqus tau nce mus txog {{{0}}}3-0.4 feem pua , thaum cov av noo ntawm kev txhaj tshuaj molding yuav tsum qis dua 0.1 feem ntau, feem ntau yog 0.04 feem pua. Lub xub ntiag ntawm cov dej ua rau npuas, cov kab roj, thiab txo cov pob tshab hauv cov yaj. Yog li nws yuav tsum tau qhuav. Qhov kub kom qhuav yog 80-90 degree, thiab lub sij hawm ziab yog ntau tshaj 3 teev. Qee zaum, 100 feem pua cov ntaub ntawv rov siv dua tuaj yeem siv tau. Tus nqi tiag tiag nyob ntawm qhov yuav tsum tau ua, feem ntau ntau dua 30 feem pua. Cov khoom siv rov ua dua tshiab yuav tsum tsis txhob muaj kuab paug, txwv tsis pub nws yuav cuam tshuam rau cov pob tshab thiab cov khoom ntawm cov khoom tiav.
2. Kev xaiv ntawm kev txhaj tshuaj molding tshuab
PMMA tsis muaj cov cai tshwj xeeb rau kev txhaj tshuaj molding tshuab. Vim nws lub siab yaj viscosity, yuav tsum tau ib tug ntxaum ntsia hlau zawj thiab ib tug loj txoj kab uas hla nozzle qhov yuav tsum tau. Yog hais tias lub zog ntawm cov khoom yuav tsum tau siab, ib tug ntsia hlau nrog ib tug loj nam piv yuav tsum tau siv rau low-temperature plasticization. Tsis tas li ntawd, PMMA yuav tsum tau muab khaws cia rau hauv lub hopper qhuav.
3. Pwm thiab rooj vag tsim
Cov pwm kub tuaj yeem yog 60 degree -80 degree . Txoj kab uas hla ntawm lub sprue yuav tsum phim lub puab taper. Lub kaum sab xis zoo tshaj plaws yog 5 degree txog 7 degree. Yog tias koj xav txhaj cov khoom nrog 4 hli lossis ntau dua, lub kaum sab xis yuav tsum yog 7 degree, thiab txoj kab uas hla ntawm lub sprue yuav tsum yog 8 txog 7 degree. 10mm, tag nrho ntev ntawm lub rooj vag yuav tsum tsis txhob ntau tshaj 50mm. Rau cov khoom uas muaj phab ntsa thickness tsawg dua 4 hli, qhov ntws channel txoj kab uas hla yuav tsum yog 6-8 hli
Rau cov khoom uas muaj phab ntsa thickness ntau dua 4 hli, txoj kab uas hla ntawm tus khiav yuav tsum yog 8-12mm. Qhov tob ntawm kab pheeb ces kaum, kiv cua-zoo li tus thiab ntsug daim ntawv rooj vag yuav tsum yog 0.7 mus rau 0.9t (t yog lub thickness ntawm cov khoom phab ntsa), thiab txoj kab uas hla ntawm rab koob rooj vag yuav tsum yog 0.8 mus rau 2mm; tsawg viscosity yuav tsum xaiv qhov me me.
Cov qhov vents yog nyob rau hauv 0.05mm tob, 6mm dav, thiab demoulding nqes hav yog nruab nrab ntawm 30′-1 degree thiab kab noj hniav yog nruab nrab ntawm 35′-1 degree 30 degree .
4. Melt kub
Nws tuaj yeem ntsuas los ntawm txoj kev txhaj tshuaj cua: xws li 210 degree txog 270 degree, nyob ntawm cov ntaub ntawv muab los ntawm tus neeg muag khoom.
Tshem lub rooj zaum tom qab, ua kom lub nozzle ntawm kev txhaj tshuaj molding tshuab tawm hauv lub ntsiab channel bushing, thiab tom qab ntawd manually nqa cov yas txhaj tshuaj molding, uas yog hollow txhaj molding.
duab
5. Kev txhaj tshuaj kub
Kev txhaj tshuaj nrawm tuaj yeem siv tau, tab sis kom tsis txhob muaj kev ntxhov siab sab hauv, nws raug nquahu kom siv ntau theem kev txhaj tshuaj, xws li qeeb-ceev-slow, thiab lwm yam. Thaum txhaj cov tuab tuab, siv qeeb ceev.
6. Lub sijhawm nyob
Yog tias qhov kub thiab txias yog 260 degree, lub sijhawm nyob hauv yuav tsum tsis pub tshaj 10 feeb; Yog tias qhov kub thiab txias yog 270 degree, lub sijhawm nyob hauv yuav tsum tsis pub tshaj 8 feeb
