Kev tshawb fawb rau cov nyhuv ntawm Screw Rotation speed ntawm Injection Molding tshuab rau Yasizing muaj peev xwm thiab Khees Viscosity

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Txhaj tshuaj pwm yog lub ntsiab khoom siv rau yas pwm, mas los ntawm qhov txhaj tshuaj. lawv, clamping lawv, tswj lub hwj tshuaj, lub kaw lus, hydrostatic transmission lawv,cua txias thiab txias, kev ruaj ntseg ntawm lub cev, lwm yam. Ua kom cov khoom zooQuantity, ntau lawm efficiency, txo zog noj, Cov neeg tau ua in-depth kev tshawb fawb rau nws. Txoj kev soj ntsuam ntawm txhaj molding cav tov yog multifaceted, nrog rau lub hwj tshuaj fais fab tuag. ntse transformation. Servo transformation ntawm transmission lawv zog txuag cua sov thiab txias lawvReform.The screw qauv transformation ntawm plasticizing muaj peev xwm. Tus screw yog tus tub ntxhais ntawm tus txhaj molding machineHeart components, Nws parameters txiav txim seb tus txhaj ntim ntawm lub tshuab txhaj tshuaj, Soj ntsuam ntawm tau kawmMore. Qhov zoo rau yas uniformity ntawm tus screw nruab nrab yog cov repetition accuracy ntawm cov khoom. Qhov kev ntsuas yooj yim dua qhov kev ntsuas accuracy, Cov kev kawm parameter ntawm plasticizing uniformity yog khees viscosity. Qhov twg cov modification ntawm tus qauv screw pab txo cov khees viscosity ntawm lub melt, ntsia hlau.

Lub peev xwm yog txiav txim tau los ntawm cov qauv screw qauv thiab cov screw speed, siab, ceev, txias, li ntawd. Nws yog lub ntsiab parameter ntsuas cov kev kawm ntawm tus screw. Wang XishMelting ntawm txhaj screwBody thauj yog analyzed theoretically. Li Zhenget the teebmeem ntawm kub thiab rov qab siab rau snailInfluence ntawm rodizing muaj peev xwm. Plasticizing peev xwm nruab nrab yog cov efficiency ntawm txhaj tshuaj molding tshuab ntau lawm,Nws yog tsim nyog los txhim kho cov plasticizing muaj peev xwm screw rau cov kev pab cuam economic cov kev pab cuam ntawm enterprises.

Lub yas muaj peev xwm ntawm tus qws refers rau qhov zoo ntawm yas khoom ib lub sij hawm ntawm qhov txhaj tshuaj molding cav tov screw. Qhov zoo ntawm cov khoom cia yog txiav txim tau los ntawm lub metering chamber, Thiab tus tawm ntawm tus screw homogenization sectionConnected nrog lub chav ntsuas, Qhov ntim ntawm qhov hluav taws xob ntawm tus screw homogenizing seem yuav tau ntsuas. Lub yas muaj peev xwm ntawm tus screw yog txiav txim tau los ntawm tus nqi kis tau tus nqi. xaiv cov ntaub ntawv, Lub viscosity yog heev cuam tshuam dab tsi los ntawm tus nqi shear thiab qhov kub degree uas tsis muaj sensitivity ntawm polypropylene los facilitate detection thiab soj ntsuam ntawm xyaum ua tej yam tau. Daim ntawv nothe ntws teb ntawm PP melt hauv lub homogenizing seem ntawm tus screw yog analyzed los fluent software.

Siv txoj kev tshawb fawb ntawm combining xyaum ua tej yam thiab theoretical tsom xam, screw rotation

Teebmeem ntawm ntau screw depths rau qhov kub, khees viscosity, velocity thiab plasticizing muaj peev xwmthe volumetric kis tau tus nqi ntawm qhov hluav taws xob ntawm lub screw homogenizing seem yog analyzed optimize lubScrew speed ntawm txhaj molding tshuab ntau lawm parameters.

1 Theoretical tsom xam daim ntawv no, Lub homogenization ntawm LYH680 yas txhaj tshuaj molding tshuab yog simulated los ntawm Fluent.Section of pipe fluid, sib txawv screw speed, Tsom xam cov homogenization seem ntawm tus pipeThe volumetric transit tus nqi ntawm qhov hluav taws xob ntawm lub propylene fluid homogenization seem yog tau txais. Cov khees viscosity ntawm PP melt thiab cov plasticizing muaj peev xwm screw tau tshawb xyuas. Theem ntawm txhaj molding machineThe relevant parameters yog: Qhov ntev ntawm lub homogenized seem ntawm tus screw yog 80 mm, thiab qhov kub ntawm lub barrel hauv lub homogenizing seem yog setSet ntawm 220 C, Lub melt siab nyob rau hauv lub homogenizing seem yog 1.5 MPa, Thiab qhov tob ntawm tus screw groove yog 2.2Mm, screw angle yog 17.66 °, screw length-diameter piv yog 19.6, screw diameter32 mm; Lub melt density ntawm polypropylene (PP) yog 770 kg / m3The melting taw tes yog 170 °C, Tus cwjpwm coefficient ntawm tus melt yog 0.182W / (m · °C), Thiab cov melt ratioHeat peev xwm ntawm 2900 J / (kg · C), melt viscosity ntawm 421 paj · s (453 K / 320)paj·s (463 K)/250 Pa·s (473 K)。 Xyaum engineering, Xav txog cov fluidThe density hloov me ntsis vim tus Disease fact tias cov molten polymer yog sheared hauv lub tshuab txhaj tshuaj thaum premolded. Shear tus nqi yog tsawg tshaj li 10-3 m / s, Thaum lub sij hawm uas lub melt nyob hauv lub non-Newtonian rheological thaj av ntawd ntawm tus thawj hauv thaj av ntawd, Tus melt polymer yuav tau regarded li ib Newtonian kua, Li ntawd, cov PP melt yog txawm ua ib incompressible laminar Newtons kua hauv lub theoretical thiab xyaum kuaj tsom xam.

• Lub tsev lag luam ntawm lub cev ua hauj lwm

Tus thawj rotating channel los ntawm cov khoom kis tau stretched rau hauv ib channel cuboid channel,Qhov chaw peb-dimensional qauv ua los ntawm lub hauv paus pib yog muaj nyob rau hauv daim duab 1 Daim Duab 3.

1.2 Lub tsev lag luam ntawm Fluid Governing Equation (φ) + faib (π φ) = div (γ kawm tiav) + S. (1) Qhov twg φ yog ib lub cev generalized variable; Tus generalized diffusion coefficient corresponding rau phi; S yog ib qhov chaw generalized.

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

dV

ρ

Z = – del Pb + π F + δ V.

(2) Nyob rau hauv cov mis nyuj: rho tawm hauj lwm, kg / m3; Vz yog cov ntws velocity nyob rau hauv kev taw qhia, m / s, Nkag mus rau hauv lub spiral groove hauv thaj av ntawd homogenization; F yog lub acceleration ntawm gravity, m / s2; Pb yog rov qab siab, paj; Yog tus melt viscosity,

paj·s; T rau lub sij hawm, s; ▽为哈密顿算子，▽= ∂ i+ ∂ j + ∂ k。 ∂x ∂y ∂z

sib npaug (2) Yog lub momentum equilibrium equation (N-S equation) viscous kua, Cov kua hauv lub spiral groove yog txawm li isothermal ntws; Lub viscosity thiab density teb yog niaj hnub zoo li. Tus width ntawm tus kauv groove yog loj tshaj qhov tob ntawm spiral groove, Thiab cov nyhuv ntawm phab ntsa screw phab ntsa yog ignored. Tus melt flows siab raws tus screw channel, uas raug nqi ntau cov nyhuv ntawm lub inlet thiab outlet, Tiam sis xaiv cov nyhuv ntawm tus nraud rov qab siab. Tus N-S equation yog yooj yim los ntawm cov mob saum toj no:

2

dp

dy=1·b。 (3) dy2eta dx

Integrate y ob zaug thiab muab ciam rau cov neeg mob (y = 0, Vz = 0; Y = h = h, Vz = π NDcos theta / 60). Cov velocity tis lub xeev muaj nuj nqi nyob rau hauv cov kev taw qhia ntawm lub melt yog tau txais, uas yog

NDyπ cos theta hy-y2pb

Vz = 120h – 2eta × Lsintheta. (4)

Qhov twg h yog qhov tob ntawm tus screw groove hauv lub homogenization seem, m; Lub helix angle ntawm tus screw, (°); L yog qhov ntev ntawm homogenized ya, m; N yog screw speed, r a d d / kuv n; D yog tus ncaj diameter ntawm tus screw qws, m.

1.3 Calculation of theoretical plasticizing peev xwm

Substituting Eq. (4) mus rau hauv lub ntsiab txhais equation, Q = WhVz = π DhVzsintheta, muab rau

22 32

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

suab. (5) 120 12 L qhov twg: W yog tus width ntawm cov kua dej, m; MPT yog theoretical yas ntawm Screw type Type Type Injection Molding tshuab

Muaj peev xwm ua tau, kg / s; Q yog qhov ntim kis tau tus nqi melt homogenization seem, m3 / s. sib npaug zos (5), Nws yuav pom tias cov plasticizing muaj peev xwm ntawm tus screw yog cuam tshuam dab tsi los ntawm ntau txoj kev parameters xws li screw diameter, screw groove angle, melt siab thiab screw groove qhov tob. Tus screw speed, muaj zog lub yas muaj peev xwm; Thaum cov khees viscosity ntawm melt tsub kom, Lub yas muaj peev xwm screw tsub kom.

Xyaum ua tej yam tau thiab simulation tsom xam

2.1 Simulation tsom xam thiab soj ntsuam

1) Tej yam kev mob rau simulation tsom xam.

Lub ntsej muag kawg: Ntawm lub velocity tis lub xeev muaj nuj nqi nyob rau hauv cov kev taw qhia ntawm lub melt (xws li (4)), Lub velocity ntawm tus inlet ntawm lub homogenizing seem hloov nrog tus nqi y. Tam sim no N = 120, 140, 160, 180 tsev dej qab / Min yog hloov mus rau hauv Vz feem, thiab tus thawj simulated velocity raws tus kauv kev taw qhia ntawm tus nkag ntawm lub homogenization seem yog txiav txim tau los ntawm lub ntsiab txhais ntawm Fluent nrog nws cov programming lus UDF, uas yog, Thawj velocity nyob rau hauv simulated thiab ntsuas cov neeg mob; Vim hais tias lub melt siab ntawm tus inlet yog tsawg dua lub taub hau screw lub taub hau siab, Lub siab ntawm lub homogenization seem yog 0; Raws li tus txheej txheem parameters ntawm PP khoom thiab khoom siv, qhov

Lub melt kub yog teem caij mus 465 K. Sab laug thiab sab xis phab ntsa: y-z dav hlau (x = x = 0), (sib npaug zos 3.2 × 10-2 m) raws li homogenization segments

Ob tog ntawm cov screw groove phab ntsa yog teem li cov phab ntsa uas tsis yog-slip phab ntsa, thiab qhov kub yog tus screw kub, uas yog teem caij mus 473 K raws li cov pp khoom cim xeeb ceem thiab cov mob ntawm cov khoom.

Sab sauv thiab sab sidewalls: x-z dav hlau (y = 0), (y = 2.2 × 10-3 m) Raws li sab thiab sab saum toj ntawm tus screw groove ntawm lub homogenization seem, Sab yog txawm ua ib phab ntsa uas tsis yog-slip phab ntsa, Qhov kub ntawm lub qhov kub yog tus screw kub, thiab qhov kub yog teem caij mus 473 K raws li cov khoom cim xeeb ceem ntawm PP thiab cov mob ntawm cov khoom; Sab saum toj ntawm tus screw groove hauv lub homogenization seem yog hu rau qhov chaw ntawm lub melt thiab cov barrel, Tus melt ntws tus nqi yog qhov ntau tshaj plaws, thiab qhov kub yog sib npaug zos rau lub barrel kub, uas yog teem caij mus 493 K raws li cov mob ntau lawm ntawm cov khoom PP khoom.

Outlet kawg fim: dav hlau x-y dav hlau (z = 0.264 m) raws li qhov hluav taws xob ntawm lub homogenization seem, lub siab outlet ciam teb yog tau txais, Qhov twg lub siab yog txheem rau cov kev taw qhia z, thiab lub siab yog teem caij mus phim cov khoom xyaum ua tej yam khoom yooj yim tsom xam thiab sib piv, thiab sab nraum qab yog teem caij mus -1.2 MPa.

• Simulation tsom xam tau

Rau x = 0.01, Lub nkhaus diagram ntawm velocity, Kub thiab viscosity ntawm tus tawm ntawm lub homogenization seem ua ib tug muaj nuj nqi ntawm lub qhov tob ntawm tus kauv groove yog muaj nyob rau hauv nuj nqis 4 mus rau 6.

Peb yuav pom los ntawm daim duab 4 Uas muaj qhov nce ntawm screw speed, Tus ceev ntawm lub homogenization seem ntawm qhov tawm kuj nce, Nrog qhov nce ntawm lub qhov tob ntawm tus screw groove, Tus ceev thawj nce thiab ces tsub kom, Nws yog them rau cov hwjchim shear thiab viscosity rau sab sauv thiab txo qhov chaw ntawm tus screw groove, Hauv kab nrog cov polymer kua hauv phaj.

Kev hloov ntawm cov kev hloov ntawm. Raws li peb yuav pom los ntawm daim duab 4, Nrog rau qhov nce ntawm screw speed, Lub velocity ntawm lub qhov hluav taws xob ntawm homogenizing seem kuj nce. Nrog rau qhov ua ntawm lub groove qhov tob, Cov velocity txo ua ntej thiab ces tsub kom. Qhov no yog them rau cov hwjchim loj shear quab yuam thiab viscosity rau sab sauv thiab txo qhov chaw ntawm lub groove, Nws yog ib yam nrog cov kev hloov polymer kua ntawm phaj. Kub hloov hauv cov kev taw qhia radial li qhia nyob rau hauv FIG. 5. Tus PP melt yog hu nrog tus screw ntawm lub qab (y = 0), saum toj no (y = 0.0022m) cua kub, sab nraud, sab sauv rau hauv lub melt, Qhov kub ntawm ob tog inward downward sib, ua ib concave kub nkhaus. Nrog qhov nce ntawm screw speed, qhov ceev tshaj 10, Lub sij hawm tshav kub kub hauv lub runner nce, thiab qhov kub ntawm qhov kub ntawm cov kiv puag ncig. Raws li muaj nyob rau hauv FIG. 6, Cov khees viscosity ntawm tus melt thawj tsub kom thiab ces txo qhov nce ntawm tus kauv qhov siab, Contrary to qhov kub nkhaus, Cov khees viscosity yog qhov tsawg tshaj plaws nyob saum lub siab melt kub, Thiab cov khees viscosity yog lub siab tshaj plaws nyob nruab nrab ntawm qhov kub tshaj plaws melt kub. Nrog qhov nce ntawm screw speed, Cov khees viscosity ntawm lub melt yog yooj yim dua thiab ntau dua, Thiab cov khees viscosity uniformity txo. Nws yuav pom tias cov khees viscosity ntawm PP melt yog inversely proportional rau kub, Uas qhia tau hais tias cov accuracy ntawm simulation.

Nws yuav pom los ntawm daim duab 6 Tias cov viscosity yuav tsis tsau nyob rau hauv cov fluent simulation, Li ntawd, peb coj qhov nruab nrab viscosity ntawm tus tawm ntawm lub homogenization seem ntawm x = 0.01 No, Vim hais tias cov viscosity hloov ntawm no los ntawm cov ntaub ntawv sib piv.

Lub viscosity uas yog ze ntawm lub theoretical calculation.

2.2 Ntsuas thiab Tsom xam txog Plasticizing peev xwm

Tom qab noj cov tshuaj txhaj tag lawm, Cov polypropylene nyoos yog muab tso rau hauv cov funnel rau yas. Tus rotating speed parameters ntawm tus screw yog teem rau 120,140,160,180 r/min, Qhov kub ntawm lub homogenized seem yog teem rau 220 °C, Thiab lub melt siab nyob rau hauv lub homogenizing seem yog teem rau 1.2 MPa. Lub sij hawm cia txhua rotating speed yog kaw nrog ib stopwatch, thiab ces tas noj yog teem caij.

Tom qab txhaj tshuaj tag, tom qab txhaj tshuaj tag, Cov huab hwm coj ntawm tus txhaj tshuaj yog sau thiab ntsuas, thiab cov yas yas uas muaj peev xwm mps yog tau los ntawm mps = 1000m/t. Qhov sib piv tau nrog lub theoretical yas muaj peev xwm mpt nyob rau hauv cov mob tib yam yog muaj nyob rau hauv Fig. 7.

Daim Duab 7 Qhia tau hais tias tus theoretical plasticizing peev xwm thiab screw speed ntawm tus screw kwv yees li ntawm ib tug muaj nuj nqi

Nrog qhov nce ntawm screw speed, Lub plasticizing muaj peev xwm screw yog enhanced, thiab cov screw screw

Qws yas muaj peev xwm tsawg dua lub theoretical yas muaj peev xwm, Lub yas yas muaj peev xwm ntawm lub tshuab txhaj tshuaj ntawm tus ceev 120 ~ 180 tsev dej qab / min accounts rau 82% ~ 86% theoretical yas muaj peev xwm, Qhia tias tus txhaj tshuaj molding tshuab screw yas muaj peev xwm saum nruab nrab. 2.3 Yuam kev tsom xam

Muaj ntau qhov txawv ntawm lub yas yas muaj peev xwm thiab theoretical yas muaj peev xwm ntawm tus screw, Tsis muaj dab tsi ntau tshaj cov ntsiab lus no: 1) Ib feem ntawm cov ntaub ntawv ib molten zaj duab xis thaum lub plasticizing txheej txheem, ua rau lub leakage ntawm cov khoom; 2) Lub leakage ntawm spiral siab yog tsis xam nyob rau hauv lub theoretical yas muaj peev xwm tsom xam, Uas los ib co ntaub ntawv nyob rau ntawm ntug. 3) Ntxiv rau lub tshav kub kub kis los ntawm lub tshav kub kub, Cov khoom no yog ntau tshaj ntawm lub tshav kub kub ntawm lub screw thiab cov friction ntawm cov ntaub ntawv, ua rau lub thermal decomposition ntawm ib feem ntawm cov khoom.

Nrog qhov nce ntawm screw speed, Lub peev xwm yas muaj peev xwm qeeb qeeb, Muaj cov ntsiab lus nram qab no: 1) Nrog qhov nce ntawm screw speed, Lub tshav kub kub ntawm tus screw yog ua, ua rau lub thermal decomposition ntawm ib feem ntawm cov khoom; 2) Qhov nce rau qhov kub txo qhov viscosity ntawm cov khoom, ua kom lub siab rov qab, hinders txoj kev kawm ntawm cov khoom, thiab ua rau lub zog yas zog qeeb qeeb.

Xaus nrog qhov nce ntawm screw groove qhov tob, Cov khaub ncaws ntawm kub thiab khees viscosity txo, thiab cov yas muaj peev xwm ua tau, Tab sis cov precision ntawm cov khoom zoo zog. Lub yas muaj peev xwm ntau zog nrog cov screw speed ua, Tab sis cov khaub ncaws ntawm kub thiab khees viscosity txo nrog qhov nce ntawm screw speed. Ua qhov kub ntawm cov screw pab txhawb cov khees viscosity uniformity thiab txhim kho qhov zoo tshaj plaws ntawm cov khoom; Thiaj li yuav xyuas kom meej tias cov khoom zoo thiab txhim kho efficiency ntau lawm efficiency, qhov tob, Kub thiab screw speed yuav tsum tau optimized.