Teeb meem thiab kev daws teeb meem hauv yas extrusion
Tshooj 1 Cov Ntsiab Cai ntawm Yas Extrusion
Kev lag luam ua cov yas yog ib qho kev siv tshuab zoo heev -raws li kev lag luam. Nws suav nrog polymer chemistry, polymer physics, interface theory, yas machinery, yas ua pwm, qauv tsim qauv thiab cov txheej txheem tswj, thiab lwm yam. Extrusion txoj kev xav tsuas yog kawm txog kev txav thiab hloov cov cai ntawm cov yas hauv extruder. Cov yas hauv extruder yog nyob rau hauv ib qho kev quab yuam sab nraud, thiab kev sib raug zoo ntawm peb lub cev lub cev ntawm cov polymer siab nyob rau hauv qhov sib txawv ntawm qhov kub thiab txias, cov qauv ntsia hlau, cov khoom yas, thiab cov kev ua haujlwm. Yuav kom ua raws li cov txheej txheem tsim nyog. Yuav kom ua tiav lub hom phiaj ntawm kev txhim kho cov khoom tsim tawm thiab cov khoom siv yas zoo. Thaum cov ntaub ntawv yas polymer raug rhuab nyob rau hauv lub siab tas li, lawv yuav tshwm sim nyob rau hauv peb lub cev lub cev: iav xeev, siab elastic xeev, thiab viscous kua xeev nyob rau hauv txawv kub ntau yam. Feem ntau, molding kub ntawm yas yog siab tshaj qhov viscous ntws kub.
Tshooj 2 Polyolefin yeeb nkab Extrusion txheej txheem tswj
Cov kev tswj tsis tau ntawm cov txheej txheem extrusion molding muaj xws li molding kub, extruder ua hauj lwm siab, ntsia hlau ceev, extrusion ceev thiab traction ceev, pub ceev, txias thiab teeb, thiab lwm yam.
1. Raw khoom pretreatment
Polyolefins tsis yog- cov ntaub ntawv nqus dej thiab feem ntau muaj cov dej noo tsawg, uas yog txaus rau extrusion, tab sis thaum polyolefins muaj dej- absorbing pigments, xws li carbon dub, lawv rhiab heev rau cov av noo. Tsis tas li ntawd, thaum siv cov khoom siv rov ua dua tshiab thiab cov khoom ntim, cov ntsiab lus dej yuav nce ntxiv. Cov dej noo tsis yog tsuas yog ua rau roughness ntawm cov yeeb nkab sab hauv thiab sab nrauv, tab sis kuj tseem tuaj yeem ua rau cov npuas npuas tshwm hauv cov yaj. Raw cov ntaub ntawv feem ntau yuav tsum tau pretreated. Kev kho kom qhuav yog feem ntau siv, thiab cov khoom siv ntxiv nrog dehumidification muaj nuj nqi kuj tuaj yeem ntxiv. Xws li defoamers, thiab lwm yam. Qhov ziab ntawm PE feem ntau yog 60-90 degrees. Ntawm qhov ntsuas kub no, cov txiaj ntsig tuaj yeem nce ntxiv los ntawm 10% - 25%.
2. tswj qhov kub thiab txias
Lub extrusion molding kub yog qhov tsim nyog los txhawb cov yas ntawm cov khoom molding thiab ntws ntawm cov yas yaj. Nws muaj kev cuam tshuam tseem ceeb heev rau cov khoom siv plasticization thiab qhov zoo thiab cov khoom tsim tawm. Lub qhov rais theoretical kub rau cov yas extrusion yog nruab nrab ntawm qhov kub thiab txias ntawm qhov degradation. Qhov kub ntau yog dav rau polyolefins. Feem ntau nws tuaj yeem ua tiav saum lub melting point thiab hauv qab 280 degrees. Yuav kom tswj tau qhov kub ntawm extrusion molding kom raug, nws yog ib qho tsim nyog yuav tsum nkag siab txog kev sib raug zoo ntawm qhov ntsuas kub ntawm cov khoom ua tiav thiab nws lub cev. Tsuas yog los ntawm kev tshawb pom nws cov yam ntxwv thiab cov kev cai tuaj yeem xaiv qhov kub zoo dua rau kev tsim cov pwm extrusion. Yog li ntawd, cov nram qab no yuav tsum tau txiav txim siab nyob rau hauv qhov kub thiab txias ntawm txhua seem: Ua ntej, cov khoom ntawm lub polymer nws tus kheej, xws li melting point, molecular yuag thiab tis, yaj Performance index, thiab lwm yam. Tom ntej no, xav txog cov kev ua tau zoo ntawm cov cuab yeej. Rau qee cov khoom siv, qhov ntsuas kub ntawm cov khoom noj muaj qhov cuam tshuam zoo rau lub sijhawm tam sim no ntawm tus tswv tsev. Ntxiv dua thiab, los ntawm kev soj ntsuam seb qhov chaw ntawm lub raj khoob extruded los ntawm lub raj tuag lub taub hau yog du. Seb puas muaj npuas thiab lwm yam tshwm sim los txiav txim.
Extrusion kub muaj xws li cua sov teeb kub thiab yaj kub. Cov cua kub kub yog hais txog qhov kub thiab txias uas muab los ntawm lub tshuab cua sov sab nraud. Lub melting kub yog hais txog qhov kub ntawm cov khoom nruab nrab ntawm sab pem hauv ntej ntawm cov ntsia hlau thiab kev sib txuas ntawm lub taub hau tshuab.
Lub thoob qhov kub thiab txias faib los ntawm thaj chaw pub rau qhov tuag yuav tiaj tus, nce, txo qis thiab sib xyaw. Nws tsuas yog nyob ntawm cov khoom taw tes thiab cov qauv ntawm extruder.
Txhawm rau teeb tsa qhov kub ntawm lub tshuab taub hau, txhawm rau kom tau txais cov txiaj ntsig zoo dua thiab cov khoom siv kho tshuab, thiab txo qhov kev nthuav dav ntawm lub qhov hluav taws xob yaj, qhov kub ntawm lub tshuab lub cev feem ntau tswj kom qis, thiab qhov kub ntawm lub tshuab taub hau yog siab. Lub siab kub ntawm lub tshuab taub hau tuaj yeem ua rau cov khoom nkag mus rau hauv pwm zoo, tab sis cov duab ruaj khov ntawm cov khoom extruded yog cov neeg pluag thiab cov nqi shrinkage nce. Yog tias qhov kub ntawm lub taub hau tshuab yog qis, cov yas ntawm cov khoom yuav tsis zoo, lub viscosity ntawm cov yaj yuav siab, thiab lub siab ntawm lub tshuab taub hau yuav nce. Although this will make the product too dense, the post-shrinkage rate is small, and the product shape stability is good, but the processing is more difficult, the mold release expansion is large, and the product surface is rough. Nws kuj tseem yuav ua rau muaj kev nce siab hauv qab ntawm lub extruder, kev thauj khoom loj ntawm cov khoom siv, thiab kev siv hluav taws xob ntau ntxiv. Qhov ntsuas kub ntawm qhov tuag, qhov kub ntawm qhov tuag thiab cov tub ntxhais pwm muaj kev cuam tshuam rau ntawm qhov kawg ntawm cov yeeb nkab. Nyob rau hauv ib qho chaw, qhov kub ntawm qhov tuag thiab cov tub ntxhais pwm ntau dua, qhov siab dua qhov ua tiav ntawm cov yeeb nkab. Feem ntau hais lus, qhov kub ntawm qhov hluav taws xob tuag yuav tsum tsis pub tshaj 220 degrees, qhov kub ntawm lub taub hau qhov hluav taws xob yuav tsum yog 200 degrees, thiab qhov kub sib txawv ntawm lub taub hau inlet thiab qhov hluav taws xob yaj yuav tsum tsis pub tshaj 20 degrees. Vim tias qhov kub thiab txias sib txawv ntawm cov yaj thiab cov hlau yuav ua rau muaj qhov tshwm sim ntawm daim tawv nqaij shark. Cov kub yaj ntau dhau ua rau tuag deposits. Tab sis nws yuav tsum tau txiav txim siab raws li qhov tseeb. Melt kub yog hais txog qhov ntsuas kub ntawm cov yaj ntsuas qhov kawg ntawm cov ntsia hlau thiab yog li qhov sib txawv ntawm qhov sib txawv. Nws tsuas yog nyob ntawm tus ntsia hlau ceev thiab lub thoob qhov kub thiab txias. Lub sab sauv txwv ntawm melt kub rau polyethylene yeeb nkab extrusion yog feem ntau teev raws li 230 degrees. Feem ntau, nws yog qhov zoo dua los tswj nws ntawm 200 degrees. Lub sab sauv txwv ntawm melt kub rau polypropylene yeeb nkab extrusion yog feem ntau 240 degrees. Melt kub yuav tsum tsis txhob siab dhau. Feem ntau, qhov degradation ntawm cov ntaub ntawv raug txiav txim siab, thiab tib lub sijhawm, qhov kub thiab txias yuav ua rau nws nyuaj rau kev tsim cov yeeb nkab.
3. Kev tswj siab
Lub siab tseem ceeb tshaj plaws hauv cov txheej txheem extrusion yog lub siab yaj, uas yog, lub taub hau siab. Feem ntau hais lus, nce lub siab yaj yuav txo qhov tso zis ntawm extruder thiab ua kom cov khoom compactness, uas yog conducive rau kev txhim kho cov khoom zoo. Tab sis kev ntxhov siab ntau dhau tuaj yeem ua rau muaj teeb meem kev nyab xeeb. Lub siab yaj yog muaj feem xyuam rau cov khoom ntawm raw cov ntaub ntawv, ntsia hlau qauv, ntsia hlau ceev, txheej txheem kub, mesh naj npawb ntawm cov ntxaij lim dej, perforated phaj thiab lwm yam. Melt siab feem ntau yog tswj ntawm 10-30MPa.
4. Kev teeb tsa lub tshuab nqus tsev
Lub tshuab nqus tsev feem ntau tswj ob qhov ntsuas ntawm lub tshuab nqus tsev kawm ntawv thiab qhov cua txias ceev. Feem ntau, nyob rau hauv qhov kev txaus siab ntawm qhov zoo ntawm cov yeeb nkab, cov qib ntawm lub tshuab nqus tsev yuav tsum tsawg li sai tau, kom lub zog sab hauv ntawm cov yeeb nkab yog me me, thiab deformation ntawm cov khoom thaum lub sij hawm cia yog me me.
5. txias
Cov dej txias qhov yuav tsum tau ua nyob rau hauv extrusion molding ntawm polyethylene kav yog feem ntau qis, feem ntau qis dua 20 degrees. Thaum tsim cov kav dej PPR, qhov ntsuas kub hauv thawj theem tuaj yeem siab dua me ntsis, thiab qhov kub thiab txias nyob rau theem tom ntej tuaj yeem qis dua, yog li tsim qhov kub thiab txias. Nws kuj tseem ceeb heev los kho cov dej txias ntws. Yog tias tus nqi ntws loj dhau lawm, qhov saum npoo ntawm cov yeeb nkab yuav ntxhib, uas ua rau cov pob thiab qhov pits. Yog tias tus nqi ntws tsawg dhau lawm, yuav muaj qhov ci ntsa iab ntawm qhov chaw ntawm cov yeeb nkab uas yooj yim tawg, xws li kev faib tsis sib luag, cov phab ntsa tuab ntawm cov yeeb nkab tsis sib xws, los yog ellipse.
6. Screw ceev thiab extrusion ceev
Screw ceev yog qhov hnyav parameter los tswj tus nqi extrusion, tso zis thiab cov khoom zoo. Qhov ceev ntawm ib qho - ntsia hlau extruder nce thiab cov zis nce ntxiv. Raws li tus nqi shear nce, qhov pom tseeb viscosity ntawm cov yaj yuav txo qis. Nws yog haum rau homogenization ntawm cov ntaub ntawv. Nyob rau tib lub sijhawm, vim yog qhov zoo ntawm plasticization, lub zog ntawm cov molecules yog nce thiab cov neeg kho tshuab lub zog zoo dua. Txawm li cas los xij, cov ntsia hlau ceev yog siab dhau lawm, lub cev muaj zog thauj khoom loj dhau, lub siab yaj siab dhau lawm, tus nqi shear siab dhau lawm, kev tuag nthuav dav ntxiv, qhov saum npoo yog deteriorated, thiab lub ntim extrusion tsis ruaj khov.
7. traction ceev
Lub traction ceev ncaj qha cuam tshuam rau cov khoom phab ntsa thickness, dimensional kam rau ua, kev ua tau zoo thiab zoo li. Lub traction ceev piv yuav tsum ruaj khov, thiab traction ceev yuav tsum phim lub extrusion ceev ntawm cov yeeb nkab. Qhov piv ntawm traction ceev rau extrusion kab ceev qhia txog qib ntawm kev taw qhia uas yuav tshwm sim hauv cov khoom. Qhov kev sib piv no yog hu ua qhov sib piv stretch, thiab nws cov nqi yuav tsum sib npaug los yog ntau dua 1. Thaum lub traction ceev nce thiab qhov cua txias thiab teeb tsa qhov kub thiab txias tsis hloov, qhov traction ceev ceev. , cov khoom nyob twj ywm hauv lub tes tsho loj thiab lub tank dej txias rau lub sijhawm luv luv, thiab yuav muaj cua sov ntau ntxiv hauv cov khoom tom qab txias thiab shaping, uas yuav ua rau cov qauv kev taw qhia ntawm cov khoom tsim thaum lub sij hawm traction. , ua rau txo qis ntawm cov℃ntawm orientation ntawm cov khoom. Qhov ceev ntawm traction ceev, lub thinner phab ntsa thickness ntawm cov yeeb nkab, thiab qhov ntau dua qhov shrinkage tus nqi ntawm cov khoom txias nyob rau hauv lub longitudinal kev taw qhia. Qhov qeeb qeeb ntawm qhov rub tawm, qhov tuab ntawm phab ntsa tuab ntawm cov yeeb nkab, qhov yooj yim dua yog ua rau cov khoom sib txuam ntawm cov tuag thiab lub tes tsho loj. Disrupt ib txwm extrusion ntau lawm. Yog li ntawd, extrusion ceev thiab rub ceev yuav tsum tau tswj kom zoo nyob rau hauv extrusion molding.
8. Ntawm -kab tswj kom zoo thiab tshaj tawm- kev ua cov kav dej
Polyolefin yog crystalline polymer, thiab muaj qhov sib txawv ntawm qhov kev ua tau zoo ntawm cov yeeb nkab tsuas yog tawm ntawm txoj kab thiab qhov loj thiab kev ua tau zoo ntawm cov khoom siv yeeb nkab thaum xa khoom. Cov laj thawj tseem ceeb yog raws li hauv qab no: ua ntej, crystallization tshwm sim thaum lub sij hawm txias ntawm polyolefin yaj, thiab crystallinity thiab crystal daim ntawv muaj feem xyuam rau qhov kub thiab txias, thermal keeb kwm, thiab lub sij hawm cia. Qhov thib ob, qhov kub ntawm cov yeeb nkab tsuas yog tawm ntawm cov kab sib dhos yog feem ntau siab dua li qhov kub thiab txias. Thib peb, qhov kev ntxhov siab sab hauv ntawm cov yeeb nkab tsuas yog tawm ntawm cov kab sib dhos yog qhov loj heev. Txhawm rau kom ua tiav qhov kev ua tau zoo thiab qhov ruaj khov, cov kav dej polyethylene dav dav yuav tsum tau muab tso tawm -kab rau 24 teev, thiab cov kav dej polypropylene yuav tsum tau muab tso rau 48 teev ua ntej ua qhov kev xeem ua haujlwm raws li cov qauv sib xws.
Tshooj 3 Cov teeb meem thiab kev daws teeb meem hauv kev tsim cov kav dej polyolefin
Polyolefin melts yog viscoelastic. Ob qhov tshwm sim feem ntau tshwm sim hauv kev ua, uas yog tuag o thiab yaj tawg. Ntawm no, nws yuav tsis tau piav qhia meej. Cov kev txawv txav hauv cov yeeb nkab ntau lawm, lawv cov laj thawj thiab kev kho mob tau teev tseg hauv qab no.
Ua rau cov mob txawv txav Cov lus pom zoo
1. raw khoom ya raws
2. Qhov kub thiab txias tsis haum
3. Cov khoom molten extruded los ntawm extruder yog tsis sib npaug
4. Lub tes tsho sizing luv dhau
5. Die forming seem luv dhau
1. Raw khoom pretreatment
2. Kho qhov kub thiab txias
3. Ua kom lub zog rov qab, siv lub tshuab lim kom zoo, thiab tsim cov qauv ntsia hlau tsim nyog
4. Extended sizing lub tes tsho
5. Extended tuag forming seem. tus
chaw nto
1. Muaj noo noo nyob rau hauv cov khoom siv raw
2. Cov npuas hauv cov kav dej hauv lub dab dej
1. Cov khoom siv qhuav qhuav
2. Tshem tawm cov npuas npuas. Kho cov txheej txheem kub. tus
Sab nrauv yog ci thiab pob tshab thaiv (feem ntau hu ua qhov muag pom tseeb)
1. Lub taub hau kub siab dhau lawm
2. Cov dej txias me me dhau los yog tsis txaus, lossis tsis sib xws
1. Txo qhov kub ntawm lub tshuab taub hau
2. Qhib cov dej txias los yog ntxuav lub tes tsho loj
Cov cim tsis tu ncua ntawm qhov du sab nrauv ntawm cov yeeb nkab Cov yeeb nkab feem ntau ua raws li lub tes tsho sizing Ua kom cov dej txias ntws los ntxuav cov dej los yog txo qhov ceev.
Sib sib zog nqus corrugation rau sab nrauv ntawm cov yeeb nkab. Qhov tuag ntawm lub tes tsho sizing tsis yog nruab nrab. Muab nws nruab nrab thiab khaws lub thawv sizing thiab tuag ntawm tib axis.
Rough puab nto
1. raw khoom ntub
2. Tsawg core pwm kub
3. Qhov sib txawv ntawm qhov tuag thiab mandrel loj heev. tus
4. Die shaping seem luv dhau
1. Raw khoom kom qhuav, los yog pretreatment
2. Ua kom kub lossis ncua sij hawm tuav
3. Hloov lub mandrel
4. Hloov mus rau qhov tuag nrog rau qhov ntev shaping seem
corrugated yeeb nkab puab phab ntsa
1. Cov zis ntawm extruder hloov pauv, thiab kev pub mis tsis ruaj khov
2. Txoj kev swb
3. Cov kav dej txias tsis sib xws
1. Txo qhov kub thiab txias hauv qhov chaw noj zaub mov. tus
2. Kho traction cua siab. tus
3. Kho txoj kev dej
Muaj cov pits ntawm phab ntsa sab hauv ntawm cov yeeb nkab
1. Cov khoom siv raw khoom noo noo
2. Tsis zoo dispersibility ntawm fillers tsis plasticization, impurities
1. Raw khoom preheating thiab ziab
2. Refueling, kho qhov kub thiab txias, ntxuav cov ntaub ntawv raw
Muaj coke hais nyob rau sab hauv phab ntsa ntawm lub raj
1. Sab hauv phab ntsa ntawm lub taub hau extruder thiab tuag tsis huv
2. Qhov kub thiab txias hauv zos yog siab dhau
3. Tuag deposits loj heev
1. Clear pwm
2. Xyuas seb lub thermocouple puas zoo li qub. tus
3. Tshem cov pwm thiab txo qhov kub ntawm qhov tuag kom tsim nyog
Hloov nyob rau hauv sab nraud txoj kab uas hla los yog phab ntsa thickness txhua lub sij hawm
1. Variation ntawm extrusion ceev
2. Kev hloov pauv hauv kev sib tw nrawm lossis swb
3. Kev pub mis tsis ruaj khov (tsis sib npaug rov qab particle loj).
4. Melt Instability
5. Kev txias txias tsis sib xws
1. Tshawb xyuas lub tsheb laij teb
2. Ua kom lub siab zoo
3. Raw khoom kuaj los yog granulation
4. Ua kom cov khoom kub, txo kab nrawm, nce qhov sib txawv
5. Ntxuav cov dej
Cov yeeb nkab phab ntsa thickness tsis sib npaug
1. Tus tuag tsis nyob nruab nrab
2. Qhov kub tsis sib xws
3. Tsheb laij teb, sizing lub tes tsho, tuag tsis sib haum
4. Qhov kev ncua deb ntawm lub tes tsho sizing thiab tuag yog deb dhau
1. Kho tuag concentricity
2. kho qhov kub thiab txias
3. nyob rau tib axis
4. txo qhov kev ncua deb
Tsis zoo welding seam
1. Qhov seem tuag yog luv dhau
2. Tsawg melting kub
3. Dispersion ntawm cov yas hauv qhov tuag
4. Lub tshuab taub hau tsis tsim nyog
1. Siv qhov seem tuag ntev dua
2. Ua kom cov khoom kub
3. Ntxuav lub taub hau tuag
4. Hloov lossis Retrofit
Cov yeeb nkab ua ntej puas tsuaj piercing
1. Lub plhaw
2. npuas
3. Cov impurities
4. Tsis zoo dispersion ntawm pigments los yog fillers
1. Cov khoom siv qhuav qhuav
2. Dehumidification lossis qis dua
3. Ntxuav cov khoom xyaw los yog siv lub tshuab lim
4. Kho qhov kub thiab txias lossis hloov cov khoom siv raw
Brittle tsis ua hauj lwm ntxov ntxov ntawm cov yeeb nkab
1. Cov khoom siv kub tsawg
2. Qhov kub thiab txias heev, cov khoom siv raw decomposes
1. Ua kom cov khoom kub
2. Ntxuav cov pwm thiab txo qhov kub
cev tawg
1. Tsawg lub taub hau kub, ceev extrusion ceev
2. Cov dej txias yog loj heev
1. cua sov, qeeb
2. Txo cov dej txias ntws
Lub roundness ntawm cov yeeb nkab tsis zoo, thiab nws yog khoov
1. Qhov chaw nruab nrab ntawm qhov tuag thiab cov tub ntxhais tuag tsis raug
2. Qhov kub tsis sib xws nyob ib ncig ntawm lub tshuab taub hau
3. Cov dej txias yog ze rau qhov tuag
4. Lub zog ntawm cov dej txias yog loj heev
5. Cov tshuaj tsuag dej txias me dhau
6. Cov dej theem siab dhau lawm
7. Lub tsheb laij teb siab dhau lawm
1. Kho concentricity
2. kho qhov kub thiab txias
3. Kho qhov dej txias qhov chaw
4. Kho lub nozzle lub kaum sab xis
5. Ntxuav cov dej
6. Cov dej ntws tawm
7. Kho cua siab
