Kev cuam tshuam ntawm viscosity thiab mob ntawm cov yas ntawm viscosity
Kev sib txhuam ntawm macromolecules hauv molten plastics yog hu ua viscosity ntawm plastics. Lub coefficient ntawm viscosity yog hu ua viscosity. Yog li ntawd, viscosity yog qhov xav txog ntawm fluidity ntawm molten plastics. Qhov loj dua qhov viscosity, lub zog yaj lub viscosity, cov fluidity tsis zoo, cuam tshuam ntau nyuaj
Nyob rau hauv daim ntawv thov kev lag luam, kev sib piv cov npliag ntawm cov yas tsis yog kom pom nws cov nqi viscosity, tab sis kom pom nws cov dej ntws tawm qhov ntsuas (MFI): MFI yog cov melt lub cev yuag dhau los ntawm tus qauv tuag hauv chav tsev lub sijhawm (feem ntau 10 feeb) hauv qab qhov kev txiav txim ntawm nyob siab nyob rau ntawm ib tug kub melting. Hauv g / 10min, piv txwv, PP cov ntaub ntawv ntawmtxhaj tshuaj qib, cov qhab nia sib txawv, MFI qhov tseem ceeb tuaj yeem sib txawv ntawm 2.5 mus rau 30, viscosity ntawm plastics tsis yog tas li. Kev hloov pauv ntawm cov khoom yas, tus cawv ntawm cov kub sab nraud, lub siab thiab lwm yam xwm txheej tuaj yeem txhawb qhov hloov ntawm viscosity
1.1 feem cuam ntawm molecular qhov ceeb thawj
Qhov loj dua cov phaus nyhav, qhov nqaim molecular yuag faib, ntau dua qhov pom viscosity
1.2 cov nyhuv ntawm cov kua roj nplaum tsis tshua muaj zog
Qhov tsis tshua muaj molecular ntxiv tuaj yeem txo qhov kev quab yuam ntawm macromolecules, yog li ntawd viscosity yog txo. Qee qhov plastics ntxiv nrog kev daws teeb meem lossis yas ua kom txo qis viscosity thiab ua kom nws pwm yooj yim
1.3 kev cuam tshuam ntawm qhov kub viscosity
Qhov kub tau ua haujlwm zoo rau lub viscosity ntawm feem ntau yaj. Qhov kub ntawm qhov nruab nrab nce ntxiv, thiab qhov qis dua qhov pom viscosity, tab sis qhov txo qis ntawm viscosity ntawm ntau plastics melts nws txawv nyob rau hauv qhov ntau
Pe / pp plastics, cov nyhuv ntawm nce qhov kub ntawm kev txhim kho fluidity thiab txo yaj yaj viscosity yog tsawg heev, qhov kub tau dhau lawm thiab kev noj yuav nce, tab sis nws tsis tsim nyog poob
Qhov kub nce viscosity ntawm pmma / pc / pa plastics poob qis ntau yam. Qhov nce ntawm PS ABS kub kuj zoo rau txo viscosity thiab moulding
1.4 tus ntawm shear nrawm
Lub viscosity ntawm plastics tuaj yeem txo los ntawm kev ua kom tiav cov shear ceev ntawm plastics zoo, tab sis qee qhov chaw, xws li PC, muaj qhov zam, thiab viscosity yuav luag ywj siab ntawm ntsia hlau ceev
1.5 qhov cuam tshuam siab
Lub siab muaj tus cwj pwm cuam tshuam rau viscosity. Feem ntau, PP PE viscosity tsis cuam tshuam los ntawm lub siab, tab sis nws muaj lub zog tseem ceeb ntawm PS. hauv qhov tseeb ntau lawm, hauv tshuab nrog cov khoom siv zoo tag nrho, nws yog qhov tsim nyog yuav tsum tau them sai sai rau qhov cuam tshuam ntawm kev txhaj tshuaj siab, uas yog, txiab siab ceev, es tsis txhob dig muag nce lub siab
Kev cuam tshuam ntawm kev txhaj tshuaj tiv thaiv kev kub tswj ntawm Molding
Lub npe hu ua qhov kub thiab txias ua kom sov yog hais txog kev siv yas ua kom sov li cas los ntawm cov khoom siv ua kom yas cov kua dej rau hauv lub thoob, uas yog, yuav ua li cas teeb lub ci qhov cub ntawm lub thoob.
2.1. Qhov ntsuas kub ntawm lub thoob yuav tsum tau muab kho kom ntseeg tau tias cov yas ntim tau zoo, thiab cov pwm txhaj tshuaj tuaj yeem ua kom ncaj ncaj yam tsis muaj qhov cuam tshuam
Qhov no xav kom peb tsis tuaj yeem nco ntsoov txo qhov kub thau ntim yas vim qhov kub siab ntawm cov yas mus rau qhov kub thiab txias, thiab yuam cov pwm txhawm los ntawm txhaj tshuaj siab lossis txhaj tshuaj nrawm
2.2. Lub siab txias ntawm cov yas ua feem ntau cuam tshuam rau kev ua tiav, thiab tseem cuam tshuam rau qhov zoo thiab xim
2.3. Kev tswj ntawm qhov ntsuas kub yog cuam tshuam nrog pwm ntawm qhov ntawm. Rau qhov loj thiab yooj yim, yog tias qhov nyhav ntawm qhov yog ze rau qhov kev txhaj tshuaj, qhov kub siab ua kom sov, nyias ntsa thiab qhov tsis zoo yuav siv. Txwv tsis pub, rau cov phab ntsa tuab, qee qhov kev ua haujlwm ntxiv, xws li cov uas muaj qhov chaw tso, tuaj yeem siv nrog qhov kub ntawm qhov cub qis, txhawm rau txheeb xyuas seb qhov kub ntawm cov kua yas yog qhov tsim nyog, nws tuaj yeem soj ntsuam los ntawm taw tes ua nyob rau hauv kev nrawm qis. Cov khoom siv tsim nyog ntsuas kub yuav tsum ua kom cov khoom siv txau kom zoo thiab muaj zog, tsis muaj npuas, caws thiab ci thiab txuas ntxiv
2.4. Cov khoom kub feem ntau nce los ntawm ntu pub khoom mus rau ntu kev paug tawm. Txawm li cas los xij, txhawm rau tiv thaiv kev ua kom tiav kev zom cov yas thiab hloov xim ntawm qhov, nws tseem tuaj yeem qis dua qis dua qhov nruab nrab. Cov khoom ntsuas kub tsis zoo thaum lub sijhawm qee zaum ua rau ntsia hlau tsis dhau - lub hau ntswj tsis tig lossis poob, uas kuj tuaj yeem tshwm sim los ntawm kev txhaj tshuaj ntau dhau lossis qhov tsis ua haujlwm ntawm lub ntsia hlau kos lub nplhaib (meson) uas ua rau cov yaj nyias yaj ntawm lub hauv ntej lub thoob tawm rov qab los rau hauv thaj chaw pub noj
Thaum cov ntaub ntawv thim rov qab no tau muab nchuav mus rau qhov sib txawv me me ntawm cov xov kawg lub ntsej muag thiab sab hauv phab ntsa ntawm lub thoob thiab txias ntawm qhov kub qis dua, zaj duab xis txias yog kaw nruj nreem nruab nrab ntawm ob phab ntsa kom cov ntsia hlau tsis tuaj yeem tig los yog thim rov qab, uas yuav cuam tshuam nrog kev pub mis
Lub sijhawm no, tsis txhob yuam kom tso tawm lossis txhaj tshuaj. Nws raug nquahu tias cov dej txias ntawm qhov chaw nres nkoj noj yuav tsum kaw ib ntus, thiab qhov kub ntawm qhov chaw pub mis yuav tsum tau nce kom txog 30-50 ℃ siab dua qhov cuam tshuam ntawm cov yas. Lub caij no, qhov kub ntawm cov seem tsis tso tawm yuav tsum ua kom tsawg rau qhov kub thiab txias. Tom qab 10-20 feeb, ua tib zoo tig lub hau ntswj, thiab rov pib siv lub tshuab thaum nws tuaj yeem tig, thiab tom qab ntawd maj mam pub
Kev tswj siab tswj kav thaum txhaj voj voog
3.1. Lub siab thov kev thov yuav tsum tau siab tshaj qhov uas muaj qhov txhij txhua. Thaum lub sij hawm txheej txheem txhaj tshuaj, lub siab ntawm pwm tswj tau nce siab kawg, thiab thaum kawg mus txog qhov siab tshaj tus nqi, uas feem ntau hu ua kev txhaj tshuaj siab. Qhov pom tseeb, kev txhaj tshuaj siab yog siab dua li ntawm qhov kev tiv thaiv txhua qhov
3.2. Siab tswj tau cov nyhuv: tom qab lub pwm kab noj hniav tau puv nrog yas kom txog thaum lub rooj vag ua kom txias tag, cov yas nyob hauv cov pwm kab noj hniav tseem tseem xav tau kev txhawb zog siab, uas yog, siab ceev. Nws lub luag haujlwm tseem ceeb yog:
A: Tus nqi ntawm cov khoom nyob ze ntawm lub rooj vag txoj hauj lwm yuav tsum tau ntxiv, thiab cov yas hauv cov pwm kab noj hniav uas tsis tau tawv ua ntej lub rooj vag hws raug kaw yuav tsum nres los ntawm ntws rov qab mus rau lub rooj vag cov khoom siv tau nyob hauv qab qhov seem
B: Tiv thaiv qhov cuam tshuam ntawm seem thiab txo qhov nqus npuas
C: Txo cov tshwm sim ntawm cov nplaum tuag tawg los yog khoov deformation vim qhov kev txhaj tshuaj ntau dhau ntawm cov ntu. Yog li ntawd, kev tswj cov siab tswj qhov siab yog feem ntau 50% - 60% ntawm qhov txhaj tshuaj siab. Yog tias lub zog tuav nias lub sijhawm lossis lub sijhawm ntev dhau, nws muaj peev xwm nyem cov khoom txias rau ntawm lub rooj vag thiab tus neeg khiav mus rau hauv qhov chaw, kom cov khoom siv txias txias ntxiv rau ze rau ntawm lub rooj vag, thiab lub voj voog tsis muaj txiaj ntsig
3.3. Kev xaiv ntawm kev txhaj tshuaj siab
A. Raws li cov duab ntawm seem. Kev xaiv Thickness. B. rau cov khoom siv yas sib txawv
Raws li cov xwm txheej ntawm kev tsim khoom thiab cov txheej txheem zoo ntawm ntu, nws raug pom zoo kom ua raws li cov txheej txheem cov txheej txheem ntawm qhov kub thiab txias siab
3.4. Hloov kho rov qab siab
Rov qab siab yog lub zog uas cov yas yas txheej txheem Dais. Kev nce qib tseem hu ua plasticizing siab
A. Cov sib xyaw xim ntawm cov xim cuam tshuam los ntawm qhov nraub qaum, qhov siab tig rov qab, qhov sib xyaw ua kom muaj zog
B. Lub nraub qaum siab pab tshem tawm txhua qhov roj cua hauv cov yas thiab txo cov tshwm sim ntawm cov nyiaj lis thiab npuas
C. Lub siab rov qab zoo tuaj yeem zam qhov tshwm sim ntawm cov khoom hauv zos nyob qis qis hauv cov thoob, yog li ntawd lub siab rov qab yog feem ntau nce thaum ntxuav lub thoob
Tswj kev txhaj tshuaj ceev
Cov cawv ntawm kev nrawm: qhov zoo ntawm cov pwm khiav ceev yog qhov nrawm nrawm, ruaj khov ntawm qhov chaw, hloov me me, tsis tshua muaj kev ntxhov siab ntawm feem, zoo sib xws ntawm sab hauv thiab sab nraud anisotropic kev ntxhov siab. Qhov tsis zoo yog tias qhov chaw ntawm cov kev kub ntxhov tsis yooj yim rau cov cim thiab cov kab dej. Kev kub ceev sau pwm tuaj yeem txais kev txhaj tshuaj qis dua los txhim kho lub ntsej muag thiab qhov muag ntawm cov khoom, tshem tawm qhov tshwm sim ntawm seam kab thiab lamination, thiab txo qhov ntsws poob siab, xim xim yog ntau yam
Qhov tsis zoo yog tias nws yog qhov yooj yim los tsim" dav hlau dawb", uas yog, ntws tsis muaj zog lossis hloov tam sim no. Qhov kub nce siab dhau lawm, xim muaj xim daj, lub tso pa taws yog qhov tsis zoo thiab qee zaum demoulding yog qhov nyuaj. Cov yas uas muaj viscosity siab tuaj yeem tsim ua lub ntsej muag sib txig, thiab cov nplaim ntawm qhov chaw yuav ua rau cov pos huab, thiab tib lub sij hawm, txoj kev nyiam ntawm viav vias khoov thiab tuab qhov tawg raws qhov sib txuam suture tshwm sim los ntawm kev ntxhov siab sab hauv
