Yeej twg tuaj yeem tshwm sim rau kev ua haujlwm ntawm qhov tsim kho tso cua ntxaig single screw extruders nyob rau hauv kev tsim kho thermal break strip?

Screw Design: Geometry, L/D Ratio, and Diameter Impact on Extrusion Efficiency

Yog li cas Screw Geometry Xaiv Txheej Txheem, Sib Puag, thiab Homogeneity ntawm Vajtxuj

Daim ntawv thiab qhauv ntawm kev them muaj feem ntau tshwm sim rau lub zog uas siv los ua kom meej sov thiab hom khoom uas tsha tseg los ntawm kev them ib leeg. Qhov loj, qhov siab ntawm cov kab uas sau, thiab cov cuab yeej sib piv zoo li kev them muaj feem ntau tshwm sim rau lub zog uas siv los ua kom meej sov thiab hom khoom uas tsha tseg los ntawm kev them ib leeg. Thaum peb hais txog qhov siab hnyav nyob rau qhov chaw ua kom sov, lawv tsim tau lub zog rub uas pab txhim kho kev sov ntev. Qhov siab nyob rau qhov chaw them muaj feem ntau tshwm sim rau lub zog uas siv los ua kom meej sov thiab hom khoom uas tsha tseg los ntawm kev them ib leeg. Rau kev sib piv, qhov chaw sib piv zoo li daim ntawv thiab kab npav tuaj yeem pab txhim kho kev sib piv. Txhawm rau kev sib piv, qhov chaw sib piv zoo li daim ntawv thiab kab npav tuaj yeem pab txhim kho kev sib piv. Rawajtiam ntawm qhov xwm yeem tseem ceeb los ntawm Ponemon thaum 2023, no tuaj yeem txo qhov sib txawv ntawm qhov sov los ntawm 12% thaum tsim cov kab ntim sov. Cov kev them muaj feem ntau tshwm sim rau lub zog uas siv los ua kom meej sov thiab hom khoom uas tsha tseg los ntawm kev them ib leeg. Cov kev them muaj feem ntau tshwm sim rau lub zog uas siv los ua kom meej sov thiab hom khoom uas tsha tseg los ntawm kev them ib leeg. Cov kev them muaj feem ntau tshwm sim rau lub zog uas siv los ua kom meej sov thiab hom khoom uas tsha tseg los ntawm kev them ib leeg.

Qhov Txoj Hneev ntawm L/D Ratio nyob rau hauv Sijhawm Txoj Hneev, Thermo Uniformity, thiab Thaj Tsam Nyob Ib Li

Qhov ntev mus rau kabntse (L/D) ratio muaj qhov tseem ceeb loj rau hauv ntau qhov chaw tseem ceeb xws li sijhawm uas khoom nyob rau hauv system, kev nyob siab ntawm melt nyob rau hauv kev tsim kho, thiab kev siv zog tag nrho. Thaum saib cov system uas muaj L/D ratios dua 30:1 kom meej li cov uas muaj txog 20:1, peb pom tias sijhawm nyob tau nce txog li 40%. Qhov sijhawm ntau no pab tau rau kev thawv yooj ywg rau cov khoom nyuaj xws li PA66 uas xav tau kev plastication zoo kawg ua ntej khiav tshuam. Tab sis thaum nce dua 40:1, qhov no yuav coj mus rau kev siv ntau dua, feem ntau nce siv zog txog li 18% tsis muaj kev pab hlo li ntau rau kev nyob ib li ntawm khoom. Ntau tus kws tshawb fik nyob hauv cheeb tsheb hais tias qhov chaw zoo tshaj plaws yog nyob ntawm 28:1 thiab 32:1 rau kev siv thermal break. Nyob rau qhov ratio no, cov neeg tsim kho tuaj yeem tswj tau ob qhov risk ntawm kev phom sij khoom thiab kuj tseem pab tau rau kev txhim kho thaj tsam feem ntau nyob ntawm 120 thiab 150 kilograms per hour.

Daim ntawv Qhia rov qab thiab Nws Lub Tswvyim Ntawm Kev Siv Hluv thiab Kev Kawg Rau Hauv Chav

Cov khoom uas tsim tau tuaj yeem tseem ceeb ntau dua nyob rau hauv qhov sib npaug ntawm qhov loj ntawm hluv. Xaiv mus saib cov leej: ib daim hluv 120mm tuaj yeem tsim tau li 2.6 lub sijhawm zoo li li 90mm hluv tso rau hauv ib lub sijhawm. Hluv loj dua yog li muaj ntau dua thiab tsim tau ntau dua (xav txog 280 kg ib teev kom rau 170 kg thaum pib los ntawm 100mm mus rau 80mm). Tab sis muaj ib qho xwm txheej. Qhov loj dua ntawm hluv, qhov siab dua ntawm kev kawg rau hauv chav, feem ntau tshwm sim tag 30% mus rau 40%. Qhov no tuaj yeem tsis zoo rau qhov chaw sib piv. Yog li ntawd, kev xaiv qhov loj raug yuav tsum nyob rau hauv yam khoom uas peb muaj. Rau yam khoom sov dav dav zoo li PVC, ntau tus neeg pom tias 90 mus rau 110mm ua haujlwm zoo. Tab sis yam khoom loj loj no xav tau ib qho me me dua, tshaj tshi 60 mus rau 80mm, los ntawm kev sib piv rau hauv chav zoo dua.

Kev Daws Txoj Cai: Saib xyuas Cov Txoj Cai Txoj Cai rau Kev Ua Haujlwm Txaus siab

Zos Kub Kub Thiab Tus Najnpawb Nws Kawm Rau Kev Siv Lub Viscosity Thiab Flow Stability

Kev txiav txim lub teb chaws uas muaj ceev tshaj plaws nyob hauv lub raj yog qhov tseem ceeb los txheej xyuas yam polymer tau dhau mus thaum tsim cov raj thermal break. Nyob hauv qhov chaw pib, kev tso caij uas tsawg dua li qhov hu ua qhov chaw kuaj ntsuab glass transition tshabs tau kom meej meej tsis tas tshuab ntau. Thaum yam khoom no tig mus hauv qhov chaw compression, peb siv kev sib txuas nrog kub tam sim ntawv feem ntau li 170 rau 190 degrees Celsius rau cov khoom siv PA66 no. Qhov no tuaj yeem kom viscosity zoo dua, yog li txhua yam raug sib mix nrog lawv li. Tom qab ntawd yog qhov chaw metering uas kev sib piv yog ib qho tseem ceeb nyob ib puag ncig ntawm kub uas tau tsim los ntawm shearing thiab kub tshiab uas peb tau ntxiv. Qhov sib piv no tuaj yeem kom kev dhau mus zoo ib txwm zoo, qhov tseem ceeb heev yog tias peb xav tau kom muaj cov ceev faj zoo ib txwm hauv +/- 1.5 percent. Ib tug neev tshou tshiab pub tseg tau qhia tias nyuaj siab dua ob thirds ntawm kev tsim tawm txoj haujlwm muaj teeb meem los ntawm kev sib txuas tsis zoo ntawm kub. Qhov no yog qhov tseem ceeb vim li cas tsoom tsoom nyiaj rau systems uas monitor cov chaw no nyob hauv real time tam sim no.

Daws kev lag luam, kev sib txig, thiab lub ntsiag tseem ceeb rau qhov chaw sov rau qhov thermal break strips

Thaum siv PA66 GF25 thermal break strips, kev txhuam xyuas rau qhov chaw tsim tshuab yuav pab ntau heev rau kev ntau dua nkev tshaj plaws thaum twb tseem nyob ib puag ncig ntawm cov nyob meem tshuab. Qhov chaw xa yuav tsum nyob ntawm 160 mus rau 170 degrees Celsius kom tso tsis pub muaj kev txhaum hauv kev sib txuas. Qhov chaw ntxuav yog nyuaj dua - nws yuav tsum tau 185 mus rau 200 degrees kom tuaj yeem tswj lub kaw lus 85% crystallinity tau zoo. Qhov chaw ntuav tom qab no yuav nyob ntawm 190 mus rau 205 degrees, uas pab tiv thaiv kev nyob ntawm 25 mus rau 35 MPa kom txhua yod tshwm tau zoo tib yod hauv die. Muaj tej ntaub ntawv industry zoo tshaj, tias muaj kev sib sau zoo tshaj rau qhov chaw ntxuav nyob hauv +/- 2 degrees thiab qhov R-value tib yod. Thiab ntawm no yog qee yam uas yuav tsum pom rau cov neeg tsim khoom xav kom kho kom tsawg: qhov precision no tuaj yeem kho kom tsawg dua li 18% kev siv hluav taws xob kom ntau dua li cov extruder systems dhau los, raws li cov kev suav zog polymer processing los ntawm early 2024.

Txhawb kev nyab xeeb ntawm vaj voog los ntawm kev tsim kho tshuab kum tes

Yog tshaj qhov ceev nruj tshaj plaws los ntawm 10 mus rau 15 degrees Celsius feem tsuas yog yuav cuam tshuam rau cov khoom siv los pab kom sov hnyav, vim nws tseem ceeb txog kev chawm dej num, uas tom qab ntawd yuav faus siab dua li 40% raws standards ASTM D256-23. Qhov chaw siv nyiaj no muaj qhov cooling system kis tau ib feeb ntawm ib sekond kom kho qhov tej yam uas ua rau sov hnyav. Qhov chaw siv cooling jacket tsim nyog rau qhov chaw uas muaj zog ntau tshaj plaws, yuav pab kom qhov teeb liab tsis txog dua li 5 degrees ntawm lub tswv yim, qhov tseem ceeb heev rau kom tuaj yeem tso kom tsis sov, tseem ceeb tshaj rau cov khoom tsis muaj halogen. Qhov kev test tau pom tias thaum tus neeg tsim khoom siv PID kom ceeb tsam kev sov, thiab hloov qhov speed ntawm screw, lawv pom tias kev cuam tshuam los ntawm kev sov hnyav tau hloov siab dua li 2/3, tab sis tsis nthuav tawm ntau npaum li 85 kilograms per hour.

Txhaj Ntawm Lub Qhov Muag thiab Kev Tswj Hauv Ke: Sib Thooj Ntawm Kev Tso Tawm thiab Qhov Txiaj Ntsim ntawm Kev Tso Tawm

Qhov txhaj ntawm lub qhov muag muaj feem ntau rau qhov twg tso tawm, thiab yam li cas los xav, kev tso tawm ceev ceev tuaj ntxiv thaum siv hauv RPM tsawg dua. Tab sis thaum peb tag kawg txog li 70 RPM, yam no yuav qhuav mus meej. Yog tias neeg twg sau ntau dua txoj kev ntawm 50 mus rau 100 RPM, lawv yuav pom tias kev tso tawm tsuav ntxiv ib puab pliag li 65%. Tsis zoo dua, tus degrees celsius yuav cuam tshuaj ntau npaum li 40 degrees vim kev rub thiab kev siv tshuaj ntawm cov khoom siv hauv. Rau tus neeg uas ua haujlwm ntawm no txhua hnub, kev sib thooj ntawm cov leej num RPM nrog yam khoom siv uas tau siv yog qhov tseemceeb heev. Xav txog HDPE, uas yog ib qho ntawm cov khoom siv plastic tseem ceeb. Cov khoom no xav tau kev siv ntau dua li 15-20% kom tsis txhob muaj kev cuam tshuaj rau tus degrees celsius hauv kev tso tawm.

Kev Txwv ntawm Vaj Koj: Kev Nyob Zoo thiab Kev Tuag Hlau nyob rau hauv Kev Sib Thaum Extrusion

Kev txwv sib thooj uas txeej kev phom nruas thiab kev sib luag hauv qhov chaw tshuab

Kev txawv ntawm lub polymer nyob hauv qhov thickness thiab qhov stretchiness muaj feem ntau hauv kev tsim pressure nyob hauv kev them nyiaj thiab tiv thaiv kev flow nyob hauv txhua qhov. Txog li cas kuj los ntawm kev xam neeg ntawm Abeykoon thiab lwm tus ntxhais tsev hauv 2020, cov khoom siv uas nyom me me nyob hauv kev puav tswj tuaj yeem txo kev siv hluav taws xob los ntawm 18% hauv qhov kev sib piv rau cov Newtonian fluids tshaib. Thaum siv modified PVC uas muaj high melt elasticity, peb feem ntau pom qhov die swell nce los ntawm 30 mus rau 40%. Qhov no txhais tau tias cov neeg tso lub screw speed yuav tsum tswj xyuas nrog siab ntau kom tau cov khoom siv uas raug rau qhov dav. Cov teeb meem nyob hauv kev flow stability zoo li melt fracture feem ntau yuav tshwm sim thaum wall shear stress nce dua li 0.25 MPa. Kom txo cov teeb meem no thiab tiv thaiv kev tsim khoom yuav tsum tsim nyob, cov neeg tsim khoom yuav tsum saib ntau hauv kev tsim qhov compression zones hauv lawv cov khoom siv.

Cov kev txawv thermal uas tiv thaiv kev nyob, kev them, thiab kev nyob hauv melt

Yam txheej xwm sib txawv ntawm kev siv khoom pab tau txaus siab rau kev sib hloov kub ntawm cov khoom. Cov roj fiberglass muaj qhov kub sib txawv tsawg dua nyob rau 0.8 mus 1.2 W/mK kom ntau dua calcium carbonate uas muaj qhov kub sib txawv zoo li 2.6 W/mK. Qhov sib txawv no cuam tshuam rau kev sib hloov kub ntawm barrels los ntawm 22 mus 35% ib yam li. Txog Polyamide 66, nws qhov ceev kub tsawg thiab yog 1.7 kJ/kgK uas txhais tau tias nws dhau los ntev nyob rau qhov chaw kho mob. Tab sis qhov kev ua no tseem ua rau nws yooj yim tuag thaum kub loj dua 295 degrees Celsius, yog li tus neeg sau khoom yuav tsum nrhiav kev kho kub zoo ib ncig rau +/- 2 degrees. Ntau qhov teeb meem pom nyob rau kev tshuaj lom zis tseem muaj feem ntau tshwm qhov tsis zoo los ntawm kev sov kub tsis raug. Lub tshawb fwm pom tias dua li 2/3 ntawm tag nrho qhov tsis zoo tshwm sim los ntawm kev sov kub tsis ntxiv nrog lub sijhawm crystallization speed, uas tshwm sim rau kev npaj ntoo sov kub.