Cov ntsia hlau ntev - rau - txoj kab uas hla (L/D) ntawm lub tshuab cua tshuab tsis yog "qhov loj dua, qhov zoo dua." Nws yog ib qho tseem ceeb uas yuav tsum tau muaj kev sib npaug ntawm cov khoom siv plasticization zoo, kev ua tau zoo, cov khoom siv, thiab cov yam ntxwv ntawm cov khoom.
Yooj yim muab tso, L / D piv yog hais txog qhov sib piv ntawm qhov ua haujlwm ntev ntawm cov ntsia hlau (L) rau nws txoj kab (D). Nws cuam tshuam ncaj qha rau lub sijhawm nyob, cov nyhuv plasticizing, thiab sib xyaw ua ke ntawm cov yas hauv lub thoob.
Qhov zoo ntawm qhov loj L / D Ratio
Kev nce qhov L / D piv muab ntau yam txiaj ntsig:
1. Zoo dua plasticization:
Cov ntaub ntawv nyob twj ywm ntev dua nyob rau hauv cov ntsia hlau thiab dhau los ua kom muaj cua sov ntau dua- cov txheej txheem tshuab, ua rau kom tiav ntau dua melting thiab sib tov sib xyaw, yog li txhim kho lub cev thiab qhov zoo ntawm zaj duab xis.
2. Muaj peev xwm tso zis ntau dua:
Nrog kev lav zoo plasticization zoo, qhov loj dua L / D piv tso cai rau cov ntsia hlau ntau dua, ua rau cov khoom siv extrusion ib zaug.
3. Kev tswj kub zoo dua:
Lub ntsia hlau ntev ntev pab tsim kom muaj qhov tsim nyog axial kub gradient, ua tau raws li qhov yuav tsum tau ua ntawm qee cov polymers tshwj xeeb.
Disadvantages ntawm ib qho loj L/D ratio
Txawm li cas los xij, qhov muag tsis pom kev nrhiav qhov loj L / D piv ua rau muaj teeb meem ntau:
1. Cov cuab yeej cuab tam nce nqi thiab kev ua haujlwm nyuaj:
Screws thiab chim yog precision-machined sib sib zog nqus- qhov thiab slender ncej. Qhov loj dua L / D piv tau nce qhov nyuaj ntawm kev siv tshuab thiab kev sib dhos, kev xav tau precision, thiab cov nqi tsim khoom.
2. Kev siv hluav taws xob ntau dua:
Lub ntsia hlau ntev dua txhais tau tias muaj kev sib txhuam ntau dua thiab qhov xav tau torque, ua rau muaj zog tsav tsheb ntau dua thiab siv zog.
3. Kev pheej hmoo ntawm thermal degradation:
Rau cov cua sov- cov yas rhiab heev xws li PVC, lub sijhawm nyob ntev heev tuaj yeem ua rau cov khoom degradation vim overheating, txo cov yeeb yaj kiab zoo.
Yuav Ua Li Cas Xaiv Qhov Zoo L/D Ratio
Lub hauv paus ntsiab lus tseem ceeb yog txuam nrog cov kev xav tau tiag tiag, raws li peb yam tseem ceeb:
1. Cov yam ntxwv ntawm cov khoom ua tiav
• Thaum tshav kub kub-sensitive plastics (piv txwv li, PVC):
Siv qhov sib piv L / D me me (feem ntau 17: 1 - 20: 1) kom txo lub sijhawm nyob thiab tiv thaiv kev degradation.
• General plastics (piv txwv li, PE, PP):
Feem ntau siv L / D piv ntawm 20: 1 - 30: 1 kom ntseeg tau tias cov yas zoo.
• Engineering plastics lossis cov ntaub ntawv tshwj xeeb (xws li PC, nplaim taws-cov khoom siv PP, iav fiber ntau ntxiv):
Yuav tsum muaj kev sib xyaw kom txaus, tso pa tawm, lossis lub sijhawm tshuaj tiv thaiv, yog li qhov loj dua L / D piv (qee zaum txog 40: 1 lossis siab dua) yog xav tau.
2. Cov khoom yuav tsum tau ua
• Rau cov khoom siv tsawg-xav tau (piv txwv li, siv cov pelletizing), qhov sib piv L/D me tuaj yeem siv los txo nqi.
• Rau siab - cov yeeb yaj kiab zoo uas yuav tsum tau ua kom pom tseeb, lub zog siab, lossis cov haujlwm tshwj xeeb, yuav tsum muaj qhov loj dua L / D piv los xyuas kom meej qhov sib xws thiab ruaj khov.
3. Khoom siv
• Rau cov ntaub ntawv granular nrog zoo flowability, qis plasticization thov tso cai rau ib tug me me L/D piv.
• Rau cov ntaub ntawv hmoov uas muaj kev sib txuas, yuav tsum muaj qhov loj dua L / D piv los xyuas kom meej kev noj qab haus huv thiab tag nrho cov yas.
Xaus
Qhov zoo tshaj plaws L / D piv yog qhov tsawg kawg nkaus tus nqi uas ua tau raws li koj cov txheej txheem thiab cov khoom tsim tawm.
Nws ua kom cov khoom zoo thaum sib npaug kev lag luam thiab kev pabcuam lub neej ntawm cov khoom siv.
