Ucwaningo Ngomphumela Wesivinini Sokuzungezisa Isikulufu Somshini Wokubumba Umjovo Emandleni Okwenza Plasticizing kanye Ne-Viscosity ebonakalayo

0 Isingeniso

Umshini wokubumba umjovo uyisisetshenziswa esiyinhloko sokubumba ipulasitiki, ikakhulukazi ngohlelo lomjovo.Isistimu, uhlelo lwe-clamping, uhlelo lokulawula ugesi, uhlelo lokuthambisa, i-hydrostatic transmission system,Isistimu yokushisisa nokupholisa, uhlelo lokuqapha ukuphepha, njll. Ukuthuthukisa ikhwalithi yomkhiqizoUbuningi, ukusebenza kahle kokukhiqiza, ukunciphisa ukusetshenziswa kwamandla, abantu benze ucwaningo olunzulu ngayo.Ucwaningo ngemishini yokubumba umjovo luningi, kuhlanganise nesistimu yokulawula ugesi.Inguquko ehlakaniphile.Ukuguqulwa kwe-Servo yesistimu yokudlulisa Ukonga amandla omshini wokushisisa nokupholisaReform.I-screw structure transformation of plasticizing ikhono. Isikulufu siwumgogodla womshini wokubumba umjovo Izingxenye zenhliziyo, amapharamitha awo anquma umthamo womjovo womshini womjovo, abacwaningi baye bafundaOkwengeziwe. Ukufana okungcono kwepulasitiki kwesikulufu kumelela ukunemba kokuphindaphinda komkhiqizo.Kuya phezulu ukunemba kokulinganisa, ipharamitha yokusebenza ye-plasticizing uniformity ibonakala i-viscosity.Lapho ukuguqulwa kwesakhiwo sesikulufa kusiza ukunciphisa ukubonakala kwe-viscosity yokuncibilika., isikulufu.

Umthamo unqunywa isakhiwo sesikulufu kanye nesivinini sesikulufu, ingcindezi, isivinini, izinga lokushisa, njll.Kuyipharamitha eyinhloko yokukala ukusebenza kwesikulufu. U-Wang XishUkuncibilika komjovo wokuthuthwa kwe-screwBody kwahlaziywa ngokwethiyori. U-Li Zhenget Imiphumela yokushisa nokucindezela emuva kumnenkeUmthelela wekhono lenduku yokwenza ipulasitiki. Umthamo we-Plasticizing umele ukusebenza kahle kokukhiqizwa komshini wokubumba umjovo,Kuyadingeka ukuthuthukisa ikhono plasticizing isikulufa izinzuzo zomnotho amabhizinisi.

Ikhono le-plasticizing lenduku libhekisela kwikhwalithi yezinto ezenziwe ngepulasitiki ngesikhathi seyunithi ngayinye yesikulufu somshini wokubumba umjovo.Ikhwalithi yokugcina impahla inqunywa igumbi lokulinganisa., kanye nokuphuma kwesigaba se-screw homogenizationKuxhunywe negumbi lokulinganisa, ivolumu ekuphumeni kwesigaba se-screw homogenizing ingalinganiswa.Ikhono lokwenza ipulasitiki lesikulufu lanqunywa izinga lokuphasa.Ekukhethweni kwezinto ezibonakalayo., i-viscosity ithintwa kakhulu izinga lokugunda kanye nezinga lokushisaIzinga lokuzwela okuphansi kwe-polypropylene ukuze kube lula ukutholwa nokubhekwa kwemiphumela yokuhlola. Leli phephaInkambu yokugeleza ye-PP encibilikayo engxenyeni ye-homogenizing yesikulufu ihlaziywa nge-Fluent software..

Ukusebenzisa indlela yocwaningo yokuhlanganisa ukuhlolwa kanye nokuhlaziywa kwethiyori, ukujikeleza kwesikulufa

Imithelela yokushona kwesikulufu okuhlukene kuzinga lokushisa, i-viscosity ebonakalayo, isivinini kanye nekhono lokwenza ipulasitikiIzinga lokuphasa kwe-volumetric ekuphumeni kwesigaba se-screw homogenizing liyahlaziywa ukuze kukhuliswe isivinini se-Screw sepharamitha yokukhiqiza umshini wokubumba umjovo.

1 Ukuhlaziywa kwethiyoriKuleli phepha, i-homogenization yomshini wokubumba umjovo wepulasitiki we-LYH680 ufaniswe yi-Fluent.Isigaba soketshezi lwamapayipi, setha isivinini se-screw esihlukile, analysis of homogenization section of the pipeThe volumetric transit rate at the outlet of the propylene fluid homogenization section is obtained.The apparent viscosity of PP melt and the plasticizing ability of screw were investigated. Phase of injection molding machineThe relevant parameters are: the length of the homogenized section of the screw is 80 mm, and the temperature of the barrel in the homogenizing section is setSet at 220 C, the melt pressure in the homogenizing section is 1.5 MPa, and the depth of the screw groove is 2.2Mm, screw screw angle is 17.66 °, screw length-diameter ratio is 19.6, screw diameter32 mm; The melt density of polypropylene (PP) was 770 kg / m3The melting point is 170 °C, the thermal conductivity coefficient of the melt is 0.182W / (m · °C), and the melt ratioHeat capacity of 2900 J / (kg · C), melt viscosity of 421 Pa · s (453 K / 320)Pa·s（463 K）/250 Pa·s (473 K)。 Kubunjiniyela obusebenzayo, cabangela uketsheziUkuminyana kuyashintsha kancane ngenxa yokuthi i-polymer encibilikisiwe igundwa emshinini wokubumba umjovo uma ibunjiwe ngaphambili. 10-3 m / s, ngaleso sikhathi ukuncibilika kutholakala endaweni engeyona eye-Newtonian rheological yokuqala Kulesi sifunda, i-polymer encibilikayo ingathathwa njengoketshezi lwe-Newtonian, ngakho-ke i-PP melt ithathwa njenge-laminar engenakucindezelwa i-Newtons fluid ekuhlaziyweni kokuhlolwa kwethiyori nokuhlola..

• Ukusungulwa kwesistimu yokuxhumanisa

Ishaneli yasekuqaleni ezungezayo lapho okudlula khona kunwetshwa kushaneli eyi-cuboid,Imodeli yesikhala enezinhlangothi ezintathu eyakhiwe kusukela emsuka iboniswa kuMdwebo 1 kuFigure 3.

1.2 Ukusungulwa kwe-Fluid Governing Equation (Phi) + i-div (p f) = div (γ gradphi) + S. (1) Where φ is a generalized physical variable; The generalized diffusion coefficient corresponding to phi; S is a generalized source term.

According to the Guangyi method, the equation of conservation of mass and momentum is established at the entrance of the homogenization section of x-y plane (z = 0).

dV

ρ

Z = – del Pb + π F + δ V.

(2) In the dt formula: rho is the melt density, kg / m3; Vz is the flow velocity in z direction, m / s, entering the spiral groove in the homogenization region; F ukusheshisa kwamandla adonsela phansi, m / s2; I-Pb iyingcindezi yangemuva, Pa; Ingabe i-viscosity encibilikayo,

Pa·s; T isikhathi, s; ▽ i-Hamiltonian，▽= ∂ i+ ∂ j+ ∂ k。 ∂x ∂y ∂z

Isibalo (2) i-equilibrium equation yomfutho (N-S isibalo) uketshezi lwe-viscous, uketshezi olusemseleni ovunguzayo luthathwa njengokugeleza kwe-isothermal; Izinkambu ze-viscosity kanye nokuminyana zifana. Ububanzi bomsele ovunguzayo bukhulu kakhulu kunokujula kwe-spiral groove, futhi umphumela wodonga oluseceleni lwesikulufa awunakwa. Ukuncibilika kugeleza ngokugcwele kushaneli yesikulufu, ukuziba umphumela wokugeleza we-inlet ne-outlet, kodwa uma kucatshangelwa umphumela we-reverse back pressure. Isibalo se-N-S senziwe lula yimibandela engenhla:

2

dp

dy=1·b。 (3) eya dx

Hlanganisa y kabili bese unikeza izimo zemingcele (y = 0, vz = 0; Y = h, Vz = π NDcos theta / 60). Umsebenzi wesimo sokusabalalisa isivinini sokugeleza lapho uncibilika khona utholwa, leyo

NDyπ cos theta hy-y2pb

I-Vz = 120h – 2kanye × Lsintheta. (4)

Lapho u-h ewukujula kwesikulufu segroove esigabeni se-homogenization, m; I-engeli ye-helix yesikulufu, (°); L ubude bengxenye ye-homogenized, m; N isivinini sesikulufu, r a d / m ngi n; D is the straight diameter of the screw rod, m.

1.3 Calculation of theoretical plasticizing capacity

Substituting Eq. (4) into the flow definition equation, Q = WhVz = π DhVzsintheta, gives

22 32

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

Pitch. (5) 120 12 L where: W is the width of the fluid section, m; I-MPT iyi-Theory Plastic Yomshini Wokubumba Umjovo Wepulasitiki Wohlobo Lwe-Screw

Umthamo wamakhemikhali, kg / s; U-Q izinga lokuphasa kwevolumu lesigaba sokuncibilika kwe-homogenization, m3 / s. Nge-equation (5), kungabonakala ukuthi ikhono le-plasticizing ye-screw lithinteka yizinhlobonhlobo zemingcele yenqubo efana nobubanzi be-screw, i-screw groove angle, ncibilikisa ukucindezela nokujula kwe-screw groove. Isivinini se-screw siphezulu, kunamandla ikhono plasticizing; Lapho i-viscosity ebonakalayo yokuncibilika iyanda, amandla e-plasticizing of screw ayanda.

Imiphumela yokuhlola nokuhlaziywa kokulingisa

2.1 Ukuhlaziywa kokulingisa kanye nemiphumela

1) Imibandela yokuhlaziywa kokulingisa.

Ubuso bokungena ngaphakathi: kusukela kumsebenzi wesimo sokusabalalisa isivinini ku-z isiqondiso sokuncibilika (njenge (4)), isivinini endaweni yokungena yesigaba se-homogenizing siyashintsha ngevelu engu-y. Manje N = 120, 140, 160, 180 i-rad / min zishintshwa zibe Vz ngokulandelana, kanye nesivinini esilingisiwe sokuqala esigudle isiqondiso sokuvunguza emnyango wesigaba se-homogenization sinqunywa ngencazelo yomsebenzi we-Fluent ngolimi lwayo lokuhlela i-UDF., leyo, isivinini sokuqala ngaphansi kwezimo ezilingisayo nezikaliwe; Ngoba ingcindezi yokuncibilika endaweni yokungena iphansi kakhulu kunokucindezela kwekhanda lesikulufa, ingcindezi ekungeneni kwesigaba se-homogenization 0; Ngokusho kwenqubo nemingcele ye-PP impahla kanye nemishini, i

Izinga lokushisa lokuncibilika lisethwe ukuze 465 K. Izindonga eziseceleni kwesokunxele nakwesokudla: y-z indiza (x = 0), (x kuyalingana 3.2 × 10-2 m) njengezigaba ze-homogenization

Izinhlangothi ezimbili zodonga lwesikulufu zisethwe njengezindonga ezingasheleli, futhi izinga lokushisa lokuncibilika liyizinga lokushisa lesikulufa, esethelwe ku 473 K ngokusho kwezimpawu ze-PP kanye nesimo sangempela semishini.

Izindonga ezisemaceleni ezingenhla nezingezansi: indiza ye-x-z (y = 0), (y = 2.2 × 10-3 m) njengezinhlangothi ezingezansi nezingaphezulu ze-screw groove yesigaba se-homogenization, uhlangothi olungezansi lubhekwa njengodonga olungasheleli, izinga lokushisa elincibilikayo yizinga lokushisa lesikulufa, futhi izinga lokushisa lisethwe ukuze 473 K ngokuya nezici ze-PP kanye nesimo sangempela semishini; Uhlangothi olungaphezulu lwe-screw groove esigabeni se-homogenization indawo yokuthintana yokuncibilika kanye nomgqomo., izinga lokuncibilika lokugeleza liphezulu, futhi izinga lokushisa lokuncibilika lilingana nezinga lokushisa lombhobho, esethelwe ku 493 K ngokwemibandela yokukhiqiza yezinto ze-PP.

Ubuso bokuphela kokuphuma: indiza ye-x (z = 0.264 m) njengendawo yokuphuma kwesigaba se-homogenization, umngcele wokuphuma kwengcindezi uyamukelwa, lapho ukucindezela kuphambene nesiqondiso sika-z, futhi ingcindezi isethelwe ukufanisa okokusebenza kokuhlola ukuze kube lula ukuhlaziya nokuqhathanisa, futhi ingcindezi yangemuva isethwe -1.2 MPa.

• Imiphumela yokuhlaziya yokulingisa

Okwe x = 0.01, umdwebo wejika wesivinini, izinga lokushisa kanye ne-viscosity ekuphumeni kwesigaba se-homogenization njengomsebenzi wokujula kwe-spiral groove kuboniswa ku-Figures. 4 ku 6.

Singabona kuFigure 4 lokho ngokwanda kwesivinini sesikulufa, isivinini sesigaba se-homogenization ekuphumeni siyanda, ngokukhula kokujula kwe-screw groove, ijubane liqala linciphe bese liyakhuphuka, okubangelwa amandla okugunda kanye ne-viscosity ezindaweni ezingaphezulu neziphansi ze-screw groove, ngokuhambisana noketshezi lwe-polymer epuletini.

Izinguquko phakathi. Njengoba sibona kuMfanekiso 4, ngokwanda kwesivinini sesikulufa, Isivinini ekuphumeni kwesigaba se-homogenizing siyakhuphuka. Ngokukhula kokujula kwe-groove, isivinini siyehla kuqala bese siyakhuphuka. Lokhu kungenxa yamandla amakhulu okugunda kanye ne-viscosity ezindaweni ezingaphezulu neziphansi ze-groove., okuhambisana nokushintshwa kwe-polymer fluid phakathi kwamapuleti. Ukushintsha kwezinga lokushisa esiqondisweni se-radial njengoba kuboniswe ku-FIG. 5. I-PP melt ixhumene nesikulufu esingezansi (y = 0), ngenhla ukuxhumana nesikulufu (y = 0.0022m) ukuqhutshwa kokushisa kwenzeka, ukushisa kusuka phansi, phezulu ku-ncibilike, izinga lokushisa elivela ezinhlangothini zombili libheke phansi, ukwakha ijika lokushisa eligobile. Ngokukhuphuka kwejubane lesikulufa, ijubane liyakhula, isikhathi sokushisa kumgijimi siyancipha, futhi izinga lokushisa liyehla ngokwanda kwenani lama-revolutions. Njengoba kuboniswe ku-FIG. 6, i-viscosity ebonakalayo yokuncibilika iyanda kuqala bese iyancipha ngokukhula kokuphakama okuvunguzayo, Ngokuphambene nejika lokushisa, i-viscosity ebonakalayo iphansi kakhulu phezulu kwezinga lokushisa eliphakeme kakhulu lokuncibilika, futhi i-viscosity ebonakalayo iphakeme kakhulu phakathi kwezinga lokushisa eliphansi lokuncibilika. Ngokukhuphuka kwejubane lesikulufa, i-viscosity ebonakalayo yokuncibilika iphezulu futhi iphakeme, futhi ukufana okubonakalayo kwe-viscosity kuncipha. Kuyabonakala ukuthi i-viscosity ebonakalayo ye-PP melt ilingana ngokuphambene nezinga lokushisa., okubonisa ukunemba kokulingisa.

Kungabonakala ku-Figure 6 ukuthi i-viscosity ayigxilile ekufanisweni kwe-Fluent, ngakho-ke sithatha i-viscosity evamile ekuphumeni kwesigaba se-homogenization ku-x = 0.01 lapha, ngoba i-viscosity iyashintsha lapha ngokuqhathanisa idatha.

I-viscosity eseduze kakhulu nesibalo setiyetha.

2.2 Isilinganiso kanye nokuhlaziywa kwamandla e-Plasticizing

Ngemuva kokushisa umshini wokubumba umjovo, i-polypropylene eluhlaza ifakwa kufaneli yepulasitiki. Amapharamitha wesivinini esijikelezayo sesikulufu asethwe kokuthi 120,140,160,180 rpm, izinga lokushisa kwesigaba homogenized isethwe at 220 °C, futhi ingcindezi yokuncibilika engxenyeni ye-homogenizing isethwe ku 1.2 MPa. Isikhathi sokugcina t ngesivinini ngasinye esizungezayo sirekhodwa ngesitophuwashi, bese kumiswa okuphakelayo okungenalutho.

Ngemuva komjovo, ngemva kokuba umjovo usupholile, ubukhulu bomjovo buqoqwa futhi bulinganiswe, futhi amandla wangempela okwenza ipulasitiki mps atholwe yi-mps = 1000m/t. Imiphumela yokuqhathanisa nekhono le-plasticizing ye-theoretical mpt ngaphansi kwezimo ezifanayo kukhonjiswe ku-Fig. 7.

Umfanekiso 7 ibonisa ukuthi umthamo we-plasticizing wetiyori kanye nesivinini sesikulufu sesikulufu silinganisa umsebenzi

Ngokukhuphuka kwejubane lesikulufa, ikhono le-plasticizing yesikulufu liyathuthukiswa, kanye nesikulufu sangempela

Ikhono le-Rod plasticizing liphansi kunekhono le-plasticizing elicatshangelwayo, ikhono langempela le-plasticizing lomshini wokubumba umjovo ngesivinini se 120 ~ 180 i-rad / ama-akhawunti amancane we 82% ~ 86% wekhono le-plasticizing theory, okubonisa ukuthi umshini wokubumba umjovo ikhono lokuhlanganisa isikulufu lingaphezu kwezinga eliphakathi. 2.3 Ukuhlaziywa kwephutha

Kunomehluko phakathi kwekhono langempela le-plasticizing kanye nekhono le-plasticizing yethiyori yesikulufu, akukho okudlula la maphuzu: 1) ingxenye yezinto yakha ifilimu encibilikisiwe ngesikhathi senqubo yokwenza ipulasitiki, okuholela ekuvuzeni kwempahla; 2) Ukuvuza komfutho we-spiral akuzange kucatshangelwe ekuhlaziyweni kwekhono le-plasticizing theory, okwenze ukuthi ezinye izinto zihlale onqenqemeni oluvunguzayo. 3) Ngaphezu kokushisa okudluliselwa yi-heater emgqonyeni, impahla ingaphezulu ekushiseni kwe-shear yesikulufu kanye nokungqubuzana phakathi kwezinto, okubangela ukubola okushisayo kwengxenye yezinto.

Ngokukhuphuka kwejubane lesikulufa, ikhono langempela le-plasticizing liyancipha, kukhona amaphuzu alandelayo: 1) Ngokukhuphuka kwejubane lesikulufa, ukushisa kwe-shear yesikulufu kuyanda, okubangela ukubola okushisayo kwengxenye yezinto; 2) Ukwanda kwezinga lokushisa kunciphisa i-viscosity yezinto, kwandisa ingcindezi ephambene, ivimbela ukuqhubeka kwento, futhi kubangela amandla e-plasticizing wangempela ukuthi ehle.

Isiphetho Ngokukhula kokujula kwe-screw groove, ukufana kwezinga lokushisa kanye ne-viscosity ebonakalayo yehla, futhi nekhono lokubeka ipulasitiki lenyuka, kodwa ukunemba kwekhwalithi yomkhiqizo kwehlile. Amandla okwenza ipulasitiki anda njengoba isivinini sesikulufa sikhula, kodwa ukufana kwezinga lokushisa kanye nokubonakala kwe-viscosity kwehla ngokunyuka kwesivinini sesikulufu. Ukwenyusa izinga lokushisa lesikulufu kusiza ukukhuthaza ukufana okubonakalayo kwe-viscosity futhi kuthuthukise ukunemba kwekhwalithi yomkhiqizo.; Ukuze kuqinisekiswe ikhwalithi yomkhiqizo futhi kuthuthukiswe ukusebenza kahle kokukhiqiza, ukujula, izinga lokushisa nesivinini sesikulufu kufanele sithuthukiswe.