Kev tshawb fawb txog qhov tshwm sim ntawm Screw Rotation Ceev ntawm Txhaj Molding Tshuab ntawm Plasticizing Muaj Peev Xwm thiab Pom Zoo Viscosity

0 Taw qhia

Txhaj tshuaj molding tshuab yog cov cuab yeej tseem ceeb rau yas molding, feem ntau yog los ntawm kev txhaj tshuaj.System, clamping system, hluav taws xob tswj qhov system, lubrication system, hydrostatic kis system,Cua sov thiab cua txias system, kev saib xyuas kev nyab xeeb, lwm yam. Txhawm rau txhim kho cov khoom zooQuantity, ntau lawm efficiency, txo lub zog noj, tib neeg tau ua qhov kev tshawb fawb tob rau nws.Qhov kev tshawb fawb ntawm kev txhaj tshuaj molding tshuab yog multifaceted, nrog rau cov hluav taws xob tswj system.Intelligent transformation.Servo transformation ntawm kis tau tus mob zog txuag ntawm cua sov thiab txias systemReform.Cov ntsia hlau qauv transformation ntawm plasticizing muaj peev xwm. Cov ntsia hlau yog lub hauv paus ntawm kev txhaj tshuaj molding tshuabHeart Cheebtsam, uas tsis muaj qhov ntsuas qhov ntim ntawm lub tshuab txhaj tshuaj, cov kws tshawb fawb tau kawm Ntau. Qhov zoo dua cov plasticizing uniformity ntawm cov ntsia hlau nruab nrab yog qhov rov ua dua qhov tseeb ntawm cov khoom.Qhov siab dua qhov ntsuas qhov tseeb, Qhov kev ua tau zoo ntawm plasticizing uniformity yog pom tseeb viscosity.Qhov kev hloov kho ntawm cov qauv ntsia hlau pab txo qhov pom tseeb viscosity ntawm cov yaj., cov ntsia hlau.

Lub peev xwm yog txiav txim los ntawm cov qauv ntsia hlau thiab cov ntsia hlau ceev, siab, ceev, kub, etc.Nws yog lub ntsiab parameter los ntsuas qhov ua tau zoo ntawm cov ntsia hlau. Wang Xish Melting ntawm kev txhaj tshuaj screwBody thauj tau soj ntsuam theoretically. Li Zhenget The effects of temperature and back pressure on snailInfluence of rod plasticizing ability. Plasticizing muaj peev xwm sawv cev rau kev ua haujlwm ntawm kev txhaj tshuaj molding tshuab ntau lawm,Nws yog ib qho tsim nyog los txhim kho lub peev xwm plasticizing ntawm cov ntsia hlau rau cov txiaj ntsig kev lag luam ntawm kev lag luam.

Lub peev xwm plasticizing ntawm tus pas nrig yog hais txog qhov zoo ntawm cov ntaub ntawv yas hauv ib lub sijhawm ntawm kev txhaj tshuaj molding tshuab ntsia hlau.Qhov zoo ntawm cov khoom cia yog txiav txim siab los ntawm lub metering chamber., thiab qhov tawm ntawm cov ntsia hlau homogenization seem txuas nrog rau chav ntsuas, qhov ntim ntawm qhov hluav taws xob ntawm cov ntsia hlau homogenizing seem tuaj yeem ntsuas tau.Lub peev xwm plasticizing ntawm cov ntsia hlau tau txiav txim siab los ntawm tus nqi dhau.Hauv kev xaiv cov ntaub ntawv, Lub viscosity yog heev cuam tshuam los ntawm shear npaum li cas thiab qhov kub thiab txiasThe degree ntawm tsawg rhiab heev ntawm polypropylene los pab kom paub thiab soj ntsuam ntawm kev sim.. Daim ntawv no Cov dej ntws ntawm PP yaj nyob rau hauv seem homogenizing ntawm cov ntsia hlau yog soj ntsuam los ntawm Fluent software.

Siv cov txheej txheem tshawb fawb ntawm kev sib xyaw ua ke thiab kev tshuaj xyuas theoretical, cov ntsia hlau tig

Cov teebmeem ntawm qhov sib txawv ntawm qhov tob ntawm qhov kub thiab txias, pom tseeb viscosity, Tshaj tawm thiab plasticizing muaj peev xwmThe volumetric pass tus nqi ntawm lub qhov hluav taws xob ntawm cov ntsia hlau homogenizing seem yog soj ntsuam kom optimize lub Screw ceev ntawm txhaj tshuaj molding tshuab ntau lawm txheej txheem tsis..

1 Theoretical tsom xam nyob rau hauv daim ntawv no, homogenization ntawm LYH680 yas txhaj tshuaj molding tshuab yog simulated los ntawm Fluent.Section ntawm cov yeeb nkab kua, teem sib txawv ntsia hlau ceev, Kev soj ntsuam ntawm homogenization seem ntawm cov yeeb nkabThe volumetric transit rate ntawm qhov hluav taws xob ntawm propylene kua homogenization seem tau txais.Qhov pom tseeb viscosity ntawm PP yaj thiab lub peev xwm plasticizing ntawm cov ntsia hlau tau tshawb xyuas.. Theem ntawm kev txhaj tshuaj molding tshuabQhov cuam tshuam tsis yog: qhov ntev ntawm homogenized seem ntawm cov ntsia hlau yog 80 mm, thiab qhov kub ntawm lub chim nyob rau hauv seem homogenizing yog teemSet ntawm 220 C, lub yaj siab nyob rau hauv homogenizing seem yog 1.5 MPa, thiab qhov tob ntawm cov ntsia hlau zawj yog 2.2Mm, ntsia hlau ntsia hlau yog 17.66 °, ntsia hlau ntev-inch ratio yog 19.6, ntsia hlau taub 32 mm; Lub melt ntom ntom ntawm polypropylene (PP) yog 770 kg / m3 Lub melting point yog 170 °C, Lub thermal conductivity coefficient ntawm yaj yog 0.182W / (m · °C), thiab melt ratioHeat peev xwm ntawm 2900 J / (kg · C), yaj viscosity ntawm 421 Pa · s (453 K / 320)Pa·s (463 K) / 250 Pa·s (473 K)。 Nyob rau hauv lub tswv yim engineering, xav txog cov kua dej Qhov ceev hloov me ntsis vim qhov tseeb hais tias cov molten polymer yog sheared nyob rau hauv lub txhaj tshuaj molding tshuab thaum premolded.Shear tus nqi yog tsawg dua. 10-3 m / s, thaum lub sij hawm lub yaj yog nyob rau hauv lub non-Newtonian rheological cheeb tsam ntawm thawj nyob rau hauv lub cheeb tsam no, cov yaj polymer tuaj yeem suav tias yog Newtonian kua, yog li lub PP yaj yog suav tias yog ib qho incompressible laminar Newtons kua nyob rau hauv lub theoretical thiab kev sim tshuaj ntsuam xyuas.

• Tsim kom muaj kev tswj xyuas qhov system

Tus thawj rotating channel los ntawm qhov uas cov khoom kis tau mus rau hauv lub cuboid channel,Qhov chaw peb sab qauv tsim los ntawm lub hauv paus chiv keeb yog qhia nyob rau hauv daim duab 1 rau daim duab 3.

1.2 Kev Tsim Nyog Kev Ua Haujlwm Kev Sib Txuas Lus (Phi) + div (p f) = div (Yog gradphi) + S. (1) Qhov twg φ yog ib qho kev sib txawv ntawm lub cev; Generalized diffusion coefficient sib haum mus rau phi; S yog lub ntsiab lus dav dav.

Raws li txoj kev Guangyi, Qhov sib npaug ntawm kev txuag ntawm huab hwm coj thiab lub zog yog tsim los ntawm qhov nkag ntawm homogenization seem ntawm x-y dav hlau (z = 0).

dV ua

r

Z = – ntawm Pb + π F + d V.

(2) Hauv dt formula: rho yog melt density, kg / m 3; Vz yog qhov khiav ceev hauv z kev taw qhia, m / s, nkag mus rau lub kauv zawj hauv cheeb tsam homogenization; F yog qhov acceleration ntawm lub ntiajteb txawj nqus, m / s 2 qib; Pb rov qab siab, Pa; Yog lub melt viscosity,

Pa·s; T rau lub sijhawm, s; ▽ yog Hamiltonian，▽ = ∂ i+ ∂ j+ ∂ k。 ∂x ∂y ∂z

Kev sib npaug (2) yog lub caij sib npaug sib npaug (N-S equation) ntawm cov kua dej khov, Cov kua nyob rau hauv lub kauv zawj yog suav tias yog isothermal flow; Cov viscosity thiab qhov ntom ntom yog sib xws. Qhov dav ntawm kauv zawj yog qhov loj dua qhov tob ntawm kauv zawj, thiab cov nyhuv ntawm cov ntsia hlau sab phab ntsa tsis quav ntsej. Lub yaj ntws tag nrho raws cov ntsia hlau channel, tsis quav ntsej qhov ntws ntawm qhov nkag thiab qhov hluav taws xob, tab sis xav txog cov txiaj ntsig ntawm qhov rov qab siab rov qab. Qhov sib npaug N-S tau yooj yim los ntawm cov xwm txheej saum toj no:

2

dp ua

dy=1·b。 (3) ua 2dx

Ua ke y ob zaug thiab muab ciam teb (y = 0, Vz = 0; Y = h, Vz = π NDcos theta / 60). Lub flow velocity faib lub xeev muaj nuj nqi nyob rau hauv cov kev taw qhia ntawm lub yaj yog tau, yog

NDyπ cos theta hy-y2pb

Vz = 120 h – 2thiab × Lsintheta. (4)

Qhov twg h yog qhov tob ntawm cov ntsia hlau zawj hauv seem homogenization, m; Lub kaum sab xis ntawm lub hau ntswj, (°); L yog qhov ntev ntawm homogenized ntu, m; N yog ntsia hlau ceev, r ib d / m i n; D yog txoj kab uas hla ntawm cov ntsia hlau ntsia hlau, m.

1.3 Kev suav ntawm theoretical plasticizing muaj peev xwm

Hloov Eq. (4) nyob rau hauv lub flow definition equation, Q = WhVz = π DhVzsynthesizer, muab

22 32

Mpt = Qπ = π D Nhрsin θ cos θ – p Dhsin

Suab. (5) 120 12 L qhov twg: W yog qhov dav ntawm cov kua dej, m; MPT yog lub theoretical yas ntawm Ntsia Hlau Hom Yas Txhaj Moulding Tshuab

Tshuaj muaj peev xwm, kg / s; Q yog qhov ntim kis tus nqi ntawm yaj homogenization seem, m 3 / s. Los ntawm kev sib npaug (5), Nws tuaj yeem pom tias lub peev xwm plasticizing ntawm cov ntsia hlau yog cuam tshuam los ntawm ntau yam txheej txheem tsis xws li ntsia hlau taub, ntsia hlau groove kaum, yaj siab thiab ntsia hlau groove tob. Qhov siab dua qhov ntsia hlau ceev, lub zog ntawm plasticizing muaj peev xwm; Thaum pom meej viscosity ntawm yaj nce, lub peev xwm plasticizing ntawm cov ntsia hlau nce.

Cov txiaj ntsig kev sim thiab simulation tsom xam

2.1 Simulation tsom xam thiab cov txiaj ntsig

1) Cov xwm txheej rau simulation tsom xam.

Lub inlet kawg ntsej muag: los ntawm qhov nrawm faib lub xeev ua haujlwm hauv z kev taw qhia ntawm yaj (xws li (4)), qhov ceev ntawm qhov inlet ntawm homogenizing seem hloov nrog tus nqi y. Tam sim no N = 120, 140, 160, 180 ua rad / min raug hloov mus rau Vz raws, thiab qhov pib simulated tshaj tawm raws li cov kev taw qhia kauv ntawm qhov nkag ntawm seem homogenization yog txiav txim siab los ntawm kev ua haujlwm txhais ntawm Fluent nrog nws tus kheej cov lus programming UDF, yog, qhov pib tshaj tawm nyob rau hauv simulated thiab ntsuas tej yam kev mob; Vim tias lub siab yaj ntawm lub inlet qis dua li lub taub hau ntsia hlau, lub siab ntawm lub inlet ntawm homogenization seem yog 0; Raws li cov txheej txheem ntawm PP cov khoom thiab cov khoom siv, cov

Lub melting kub yog teem rau 465 K. Sab laug thiab sab xis phab ntsa: y-z dav (x = 0), (x sib 3.2 × 10-2 m) raws li homogenization ntu

Ob sab ntawm cov ntsia hlau zawj phab ntsa yog teem raws li cov phab ntsa uas tsis yog-slip, thiab qhov kub ntawm qhov kub yog qhov ntsuas kub, uas yog teem rau 473 K raws li cov khoom siv PP thiab qhov tseeb ntawm cov khoom siv.

Upper thiab qis sidewalls: x-z dav (y = 0), (y = 2.2 × 10-3 m) raws li sab qis thiab sab sauv ntawm cov ntsia hlau zawj ntawm seem homogenization, sab qis yog suav tias yog phab ntsa uas tsis yog-slip, qhov ntsuas kub yog qhov ntsuas kub, thiab qhov kub thiab txias yog teem rau 473 K raws li cov khoom siv ntawm PP thiab qhov tseeb ntawm cov khoom siv; Sab saum toj ntawm cov ntsia hlau zawj nyob rau hauv seem homogenization yog qhov sib cuag ntawm cov yaj thiab lub thoob, melt flow rate yog qhov siab tshaj plaws, thiab lub melt kub yog sib npaug rau lub thoob lub rhaub kub, uas yog teem rau 493 K raws li kev tsim khoom ntawm cov khoom siv PP.

Qhov hluav taws xob kawg lub ntsej muag: x-y dav (z = 0.264 m) raws li qhov hluav taws xob ntawm homogenization seem, lub siab qhov hluav taws xob ciam teb yog saws, qhov twg lub siab yog opposite rau z kev taw qhia, thiab lub siab yog teem kom phim cov cuab yeej sim kom yooj yim txheeb xyuas thiab sib piv, thiab lub siab rov qab yog teem rau -1.2 MPa.

• Simulation tsom xam cov txiaj ntsig

Rau x = 0.01, daim duab nkhaus ntawm velocity, kub thiab viscosity ntawm qhov tawm ntawm homogenization seem raws li ib tug muaj nuj nqi ntawm qhov tob ntawm lub kauv zawj yog qhia nyob rau hauv cov duab 4 rau 6.

Peb tuaj yeem pom ntawm daim duab 4 uas nrog qhov nce ntawm cov ntsia hlau ceev, qhov ceev ntawm homogenization seem ntawm qhov tawm kuj nce, nrog rau qhov nce ntawm qhov tob ntawm cov ntsia hlau zawj, qhov ceev thawj zaug txo thiab ces nce, uas yog vim lub zog shear thiab viscosity nyob rau sab sauv thiab qis ntawm cov ntsia hlau zawj, nyob rau hauv txoj kab nrog cov kua dej polymer hauv lub phaj.

Hloov ntawm. Raws li peb tuaj yeem pom ntawm daim duab 4, nrog rau qhov nce ntawm cov ntsia hlau ceev, Qhov nrawm ntawm qhov hluav taws xob ntawm homogenizing seem kuj nce. Nrog rau qhov nce ntawm qhov groove qhov tob, qhov nrawm txo ua ntej thiab tom qab ntawd nce. Qhov no yog vim qhov loj shear quab yuam thiab viscosity nyob rau sab sauv thiab qis ntawm qhov zawj., uas yog raws li kev hloov pauv ntawm cov kua dej polymer ntawm daim hlau. Qhov kub thiab txias hloov nyob rau hauv radial kev taw qhia raws li qhia nyob rau hauv FIG. 5. Lub PP yaj yog nyob rau hauv kev sib cuag nrog cov ntsia hlau nyob rau hauv qab (y = 0), saum toj no kev sib cuag nrog cov ntsia hlau (y = 0.0022 m) Thaum tshav kub kub conduction tshwm sim, cua sov los ntawm hauv qab, lub Upper rau hauv melt, qhov kub ntawm ob sab sab hauv downward trend, tsim ib tug concave kub nkhaus. Nrog rau qhov nce ntawm cov ntsia hlau ceev, ceev nce, lub sij hawm cua sov hauv cov neeg khiav dej num txo, thiab qhov kub thiab txias txo nrog qhov nce ntawm tus naj npawb ntawm revolutions. Raws li qhia hauv FIG. 6, qhov pom tseeb viscosity ntawm cov yaj ua ntej nce thiab tom qab ntawd txo qis nrog qhov nce ntawm qhov siab ntawm kauv., Contrary to the kub nkhaus, qhov pom tseeb viscosity yog qhov qis tshaj plaws nyob rau sab saum toj ntawm qhov kub tshaj plaws yaj, thiab qhov pom tseeb viscosity yog qhov siab tshaj plaws ntawm qhov nruab nrab ntawm qhov qis tshaj qhov kub. Nrog rau qhov nce ntawm cov ntsia hlau ceev, qhov pom tseeb viscosity ntawm cov yaj yog siab dua thiab siab dua, thiab pom meej viscosity uniformity txo. Nws tuaj yeem pom tias qhov pom tseeb viscosity ntawm PP yaj yog inversely proportional rau kub, uas qhia qhov tseeb ntawm simulation.

Nws tuaj yeem pom ntawm daim duab 6 hais tias lub viscosity tsis tas nyob rau hauv lub simulation Fluent, yog li peb coj qhov nruab nrab viscosity ntawm qhov tawm ntawm homogenization seem ntawm x = 0.01 ntawm no, vim qhov viscosity hloov ntawm no los ntawm kev sib piv cov ntaub ntawv.

Lub viscosity uas yog ze tshaj rau kev xam qhov theoretical.

2.2 Kev Ntsuas thiab Kev Ntsuam Xyuas Plasticizing muaj peev xwm

Tom qab preheating lub tshuab txhaj tshuaj molding, polypropylene raw khoom yog muab tso rau hauv lub funnel rau plasticity. Lub rotating ceev parameters ntawm cov ntsia hlau yog teem rau 120,140,160,180 rpm ua, qhov kub ntawm qhov homogenized seem yog teem rau 220 °C, thiab cov yaj siab nyob rau hauv seem homogenizing yog teem rau 1.2 MPa. Lub sij hawm cia t ntawm txhua qhov kev sib hloov ceev yog kaw nrog lub sijhawm nres, thiab tom qab ntawd lub khoob pub yog teem.

Tom qab txhaj tshuaj, tom qab txhaj tshuaj yog txias, qhov loj m ntawm kev txhaj tshuaj yog sau thiab ntsuas, thiab qhov tseeb plasticizing muaj peev xwm mps tau los ntawm mps = 1000m / t. Cov txiaj ntsig sib piv nrog cov theoretical plasticizing muaj peev xwm mpt nyob rau hauv tib yam xwm txheej tau qhia hauv Daim duab. 7.

Daim duab 7 qhia tau hais tias qhov theoretical plasticizing muaj peev xwm thiab cov ntsia hlau ceev ntawm cov ntsia hlau kwv yees ib txoj haujlwm

Nrog rau qhov nce ntawm cov ntsia hlau ceev, lub peev xwm plasticizing ntawm cov ntsia hlau yog txhim kho, thiab qhov tseeb ntsia hlau ntsia hlau

Qws plasticizing muaj peev xwm qis dua qhov theoretical plasticizing muaj peev xwm, qhov tseeb plasticizing muaj peev xwm ntawm kev txhaj tshuaj molding tshuab ntawm qhov ceev ntawm 120 ~ 180 ua rad / min account rau 82% ~ 86% ntawm theoretical plasticizing muaj peev xwm, qhia tias lub tshuab txhaj tshuaj molding tshuab ntsia hlau plasticizing muaj peev xwm siab tshaj qhov nruab nrab. 2.3 Kev soj ntsuam yuam kev

Muaj qhov sib txawv ntawm qhov tseeb plasticizing muaj peev xwm thiab theoretical plasticizing muaj peev xwm ntawm cov ntsia hlau, tsis muaj dab tsi ntau tshaj li cov ntsiab lus no: 1) ib feem ntawm cov ntaub ntawv tsim ib zaj duab xis molten thaum lub sij hawm plasticizing txheej txheem, ua rau cov khoom xau; 2) Lub to ntawm kauv siab tsis tau txiav txim siab nyob rau hauv theoretical plasticizing muaj peev xwm tsom xam, uas ua rau qee cov ntaub ntawv nyob rau ntawm ntug kauv. 3) Ntxiv nrog rau cov cua sov kis los ntawm lub thoob lub rhaub, cov khoom yog ntau dua los ntawm shear tshav kub ntawm cov ntsia hlau thiab kev sib txhuam ntawm cov ntaub ntawv, ua rau thermal decomposition ntawm ib feem ntawm cov khoom.

Nrog rau qhov nce ntawm cov ntsia hlau ceev, qhov tseeb plasticizing muaj peev xwm yog qeeb, muaj cov ntsiab lus hauv qab no: 1) Nrog rau qhov nce ntawm cov ntsia hlau ceev, shear tshav kub ntawm cov ntsia hlau yog nce, ua rau thermal decomposition ntawm ib feem ntawm cov khoom; 2) Qhov nce hauv qhov kub thiab txias txo qhov viscosity ntawm cov khoom, nce qhov rov qab siab, cuam ​​tshuam qhov kev nce qib ntawm cov khoom, thiab ua rau lub zog tiag tiag plasticizing qeeb.

Xaus Nrog qhov nce ntawm cov ntsia hlau zawj qhov tob, lub uniformity ntawm qhov kub thiab txias viscosity poob, thiab lub peev xwm plasticizing tau nce, tab sis qhov tseeb ntawm cov khoom zoo tau txo qis. Lub peev xwm plasticizing tau nce nrog cov ntsia hlau nrawm nce, tab sis qhov sib xws ntawm qhov kub thiab txias thiab pom tseeb viscosity poob nrog qhov nce ntawm cov ntsia hlau ceev. Ua kom qhov kub thiab txias ntawm cov ntsia hlau pab txhawb qhov pom tseeb viscosity uniformity thiab txhim kho qhov zoo ntawm cov khoom.; Txhawm rau kom ntseeg tau cov khoom zoo thiab txhim kho kev tsim khoom, qhov tob, kub thiab ntsia hlau ceev yuav tsum optimized.