Cov khoom siv PMMA feem ntau hu ua plexiglass, acrylic, thiab lwm yam. Lub npe tshuaj yog polymethyl methacrylate. PMMA yog cov khoom tsis muaj tshuaj lom thiab ib puag ncig tus phooj ywg. Qhov loj tshaj plaws feature yog siab transparency, nrog lub teeb transmittance ntawm 92%. Ib qho uas muaj lub teeb pom kev zoo tshaj plaws, UV xa tawm kuj tseem nce mus txog 75%, thiab cov khoom siv PMMA kuj muaj tshuaj lom neeg ruaj khov thiab huab cua tsis kam.
PMMA acrylic cov ntaub ntawv feem ntau yog siv los ua cov nplooj ntawv acrylic, acrylic yas pellets, acrylic lub teeb lub thawv, acrylic da dej, thiab lwm yam. Cov khoom siv ntawm lub tsheb yog cov tsheb loj, cov teeb liab teeb, cov twj paj nruag, thiab lwm yam., kev lag luam tshuaj (ntshav cia. ntim), cov ntawv thov kev lag luam (video discs, lub teeb diffusers) ), cov nyees khawm ntawm cov khoom siv hluav taws xob (tshwj xeeb yog pob tshab), cov khoom siv (cov khob haus, ntawv sau, thiab lwm yam).
Lub fluidity ntawm PMMA cov khoom yog phem dua li ntawm PS thiab ABS, thiab yaj viscosity yog rhiab heev rau cov kev hloov ntawm kub. Hauv cov txheej txheem molding, kev txhaj tshuaj kub yog siv los hloov cov viscosity yaj. PMMA yog amorphous polymer nrog melting kub siab tshaj 160 ℃ thiab decomposition kub ntawm 270 ℃. Cov txheej txheem molding ntawm PMMA cov ntaub ntawv suav nrog casting,txhaj tshuaj molding, machining, thermoforming, thiab lwm yam.
1. Kev kho cov yas
PMMA muaj qee qhov nqus dej, thiab nws qhov nqus dej yog 0.3-0.4%, thiab qhov ntsuas kub ntawm qhov txhaj tshuaj yuav tsum qis dua 0.1%, feem ntau yog 0.04%. Lub xub ntiag ntawm cov dej ua rau cov yaj tshwm ua npuas, roj streaks, thiab txo cov pob tshab. Yog li nws yuav tsum tau qhuav. Qhov kub kom qhuav yog 80-90 ℃, thiab lub sijhawm ntau tshaj 3 teev.
Qee zaum, 100% ntawm cov khoom siv rov ua dua tuaj yeem siv tau. Tus nqi tiag nyob ntawm qhov yuav tsum tau ua. Feem ntau, nws tuaj yeem tshaj 30%. Cov khoom siv rov ua dua tshiab yuav tsum tsis txhob muaj kev sib kis, txwv tsis pub nws yuav cuam tshuam rau qhov pom tseeb 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 cov viscosity siab, yuav tsum muaj lub qhov tob tob tob thiab lub qhov taub loj dua. 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-ken kub tuaj yeem yog 60 ℃ -80 ℃. Txoj kab uas hla ntawm lub sprue yuav tsum phim lub puab taper. Lub kaum sab xis zoo tshaj plaws yog 5 ° txog 7 °. Yog tias koj xav txhaj 4 hli lossis ntau dua cov khoom, lub kaum sab xis yuav tsum yog 7 °, thiab txoj kab uas hla ntawm sprue yuav tsum yog 8 °. Txog 10mm, tag nrho qhov ntev ntawm lub rooj vag yuav tsum tsis pub tshaj 50mm. Rau cov khoom uas muaj phab ntsa thickness tsawg tshaj li 4 hli, tus khiav txoj kab uas hla yuav tsum yog 6-8 hli, thiab rau cov khoom uas muaj phab ntsa thickness ntau tshaj 4 hli, cov khiav txoj kab uas hla yuav tsum yog 8-12 hli.
Qhov tob ntawm kab pheeb ces kaum, kiv cua-zoo li tus thiab ntsug-shaped rooj vag yuav tsum yog 0.7 mus rau 0.9t (t yog cov phab ntsa thickness ntawm cov khoom), thiab txoj kab uas hla ntawm rab koob rooj vag yuav tsum yog 0.8 mus rau 2 hli; rau cov viscosity tsawg, yuav tsum tau siv me me. Cov qhov vents feem ntau yog 0.05 txog 0.07mm tob thiab 6mm dav.Qhov demolding txoj kab nqes yog nruab nrab ntawm 30′-1 ° thiab 35′-1 ° 30 ° hauv kab noj hniav.
4. Melting kub
Nws tuaj yeem ntsuas los ntawm txoj kev txhaj tshuaj cua: xws li 210 ℃ to 270 ℃, nyob ntawm cov ntaub ntawv muab los ntawm tus neeg muag khoom.
5. Kev txhaj tshuaj kub
Kev txhaj tshuaj nrawm tuaj yeem siv tau, tab sis kom tsis txhob muaj kev ntxhov siab sab hauv, kev txhaj tshuaj ntau theem yuav tsum tau siv, 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 ℃, lub sijhawm nyob hauv yuav tsum tsis pub tshaj 10 feeb, thiab yog tias qhov kub thiab txias yog 270 ℃, lub sijhawm nyob hauv yuav tsum tsis pub tshaj 8 feeb.
Post lub sij hawm: May-25-2022
