Xyuas kom qhuav
Nylon yog ntau hygroscopic, yog raug rau huab cua ntev, yuav nqus noo noo hauv cov huab cua. Ntawm qhov kub siab tshaj qhov poelting pot (li 254 ° C), dej lwg me me tawm qauv nrog nylon. Cov tshuaj tiv thaiv no, hu ua hydrolysis lossis cleavage, oxidizes rau nylon thiab discolor nws. Qhov hnyav molecular thiab cov tawv nqaij tawv ntawm cov cob yog muaj zog tsis muaj zog, thiab cov fluidity muaj ntau dua. Lub noo noo abrathbed los ntawm cov yas thiab cov roj tawg tawm ntawm cov chaw sib koom ua ke, speckle, cov pa roj me, tsis muaj peev xwm ua kom ruaj khov los yog tsim cov tshuab hluav taws xob tsawg dua. Thaum kawg, nylon cleaved los ntawm cov hydrolysis yog tag nrho irreducible thiab tsis tuaj yeem siv dua txawm hais tias nws yog rov ua dua.
Cov khoom siv nylon ua ntej txhaj tshuaj molding tshuab ziab khaub ncaws yuav tsum tau ua kom tiav ntawm cov khoom tiav los ntawm kev yuav tsum tau ua tiav rau 0.1% hauv qab no, kom ntev li cov khoom siv raw kom qhuav, txhaj tshuaj molding yog Ib qho yooj yim, cov ntu yuav tsis nqa cov teeb meem ntau ntawm qhov zoo.
Nylon tau zoo siv lub tshuab ziab khaub ncaws kom qhuav, yog cov khoom siv tawm hauv huab cua thiab cov khoom siv oxygen mentsle, cov khoom siv oxidation los kuj tseem muaj cov nyhuv rov qab, yog li ntawd uas kev tsim khoom ntawm nkig.
Thaum tsis muaj lub tshuab nqus tsev kom qhuav, tshuab ziab khaub ncaws kom qhuav tuaj yeem siv tau, txawm tias cov nyhuv tsis zoo. Muaj ntau cov lus sib txawv rau kev ua kom qhuav cua kom qhuav, tab sis ntawm no tsuas yog qee qhov. Thawj yog 60 ℃ ~ 70 ℃, cov ntaub ntawv txheej txheej tuab 20mm, ci 24h ~ 30h; Qhov thib ob tsis yog ntau tshaj 10h thaum qhuav qis dua 90 ℃; Qhov thib peb yog ntawm 93 ℃ lossis hauv qab no, ziab 2h ~ 3h, vim tias muaj kev hloov nylon ntau dua li 79 ℃; Plaub yog kom nce qhov kub kom ntau tshaj 100 ℃, lossis txawm tias yog kev txiav txim siab nylon raug rau kev ua haujlwm nylon raug rau cov khoom siv tsis zoo; Thib tsib yog txhaj tshuaj molding tshuab kub Hopper ziab, qhov kub ntawm cov cua kub tau tsa kom tsawg dua 100 ℃ lossis siab dua, kom cov dej noo hauv cov yas yaj. Tom qab ntawd cov huab cua kub tau coj mus deb ntawm kev cia siab.
Yog tias cov yas qhuav yog nthuav dav hauv huab cua, nws yuav ua kom cov dej sai sai hauv huab cua thiab poob cov nyhuv kom qhuav. Txawm nyob hauv lub tshuab npog, lub sijhawm cia yuav tsum tsis txhob ntev, feem ntau tsis ntau tshaj 1 teev nyob rau hnub los nag, hnub ci hnub yog txwv rau 3 teev.
Tswj Barrel Kub
Nylon melting ntsuas kub yog siab, tab sis thaum mus txog rau lub zog melting, nws qhov viscosity yog ntau dua li dav hlau thermoplastics xws li polystyrene, yog li tsim cov fluidity, yog li kev tsim cov fluidity tsis yog teeb meem. Ib qho ntxiv, vim muaj cov khoom sib txawv ntawm nylon, qhov ntsuas kub nce ntxiv, thiab cov khoom siv kub me me, yog li cov khoom kub yog qhov lav tau pwm.
Tab sis nylon nyob rau hauv lub xeev melting thaum lub thermal stability yog tsis zoo, ua rau cov khoom siv hluav taws xob ntev dhau yuav ua rau muaj zog, yog lub zog tshwm sim. Yog li ntawd, qhov ntsuas kub ntawm txhua ntu yuav tsum nruj me ntsis tswj, yog li cov pa taws kub ua tau, kom tsis txhob muaj peev xwm ua tau, kom tsis txhob muaj qee qhov tsis zoo thiab ua rau muaj kev phem. Raws li rau tag nrho cov pwm, qhov ntsuas kub, qhov ntsuas kub ntawm lub thoob yuav tsum tsis pub tshaj 300 ℃, thiab lub caij sov ntawm pellet nyob rau hauv lub thoob yuav tsum tsis pub tshaj 30min.
Txhim Kho Cov Khoom Siv Khoom Siv Khoom
Qhov thib ib yog qhov xwm txheej hauv lub thoob, txawm hais tias muaj cov khoom siv txuas ntxiv, tab sis cov khoom ntws ntawm cov ntsia hlau kawg ntawm lub hau ntswj thiab sab hauv phab ntsa ntawm cov thoob tsib tau nce ntxiv Vim hais tias ntawm cov kev ua kom loj, uas tsis tsuas yog txo qhov kev txhaj tshuaj kom zoo thiab muaj peev xwm pub rau kev noj qab haus huv, yog li ntawd lub hau ntswj tsis tuaj yeem plam rov qab. Yog li no, ib lub voj kos yuav tsum tau muab ntsia nyob rau pem hauv ntej ntawm lub thoob txwv kom tiv thaiv backflow. Tab sis tom qab txhim kho cov ntiv nplhaib, cov khoom kub yuav tsum tau nce ntxiv los ntawm 10 ℃ ~ 20 ℃ Yog li ntawd lub siab ploj tuaj yeem raug them nyiaj.
Qhov thib ob yog lub nozzle, kev txhaj tshuaj tau ua tiav, lub hau rov qab, tus ntsia hlau siab tuaj yeem tawm ntawm lub siab tawv tuaj yeem tawm ntawm lub siab tawv, uas yog, hu ua "salivation prenomenon". Yog tias cov khoom siv tau qaub ncaug rau cov kab noj hniav yuav ua rau cov khoom siv txias lossis yog qhov ua haujlwm ntawm cov teeb meem, kev lag luam tsis raug nqi. Nws yog txoj hauv kev zoo los tswj qhov ntsuas kub ntawm lub nozzle los ntawm kev hloov pauv cua sov, tab sis cov txheej txheem sib cais yog hloov lub nozzle nrog lub caij nplooj ntoo hlav. Yog lawm, cov khoom siv caij nplooj ntoo hlav siv los ntawm qhov nozzle yuav tsum tau tiv taus qhov kub thiab txias vim tias yuav rov ua haujlwm ntxiv rau kev siv kub.
Ua kom muaj kev tso pa tawm thiab tswj kev tuag kub
Vim tias lub siab yaj taw tes ntawm nylon, nws taw tes khov kuj tseem ceeb rau lub sijhawm txias rau lub sijhawm txias, tiv thaiv kev ua tiav ntawm cov pwm sau , yog li kev txhaj tshuaj tiv thaiv nrawm yuav tsum tau siv, tshwj xeeb tshaj yog rau cov khoom nyias nyias lossis cov dej ntws ntev. Tsis tas li ntawd, kev kub ceev pwm clicum sau kuj coj cov kab noj kab noj hniav ua kom muaj teeb meem, cov pwm nylon yuav tsum muaj kev ua kom muaj kev sib luag.
Nylon muaj ntau dua txoj kev tuag kub ntau dua li dav dav thermoplastics. Feem ntau hais lus, siab dua pwm kub yog qhov ntsuas rau ntws. Nws yog ib qho tseem ceeb heev rau cov ntu nyuaj. Qhov teeb meem yog tias tus nqi txias me ntsis tom qab sau cov kab noj hniav muaj qhov cuam tshuam tseem ceeb rau cov qauv thiab cov khoom ntawm cov ntaub nylon. Mas cov lus dag nyob rau hauv nws cov crystallization, thaum nws nyob rau hauv lub siab kub nyob rau hauv ib kab noj hniav, qhov loj me ntawm lub crystallization tus nqi yog qhov siab thiab tus nqi hloov cua kub. Thaum qhov seem nyias nrog elongation siab, zoo transparency thiab nruj yuav tsum muaj, cov pwm kub yuav tsum txo qis cov crystallization. Thaum lub phab ntsa tuab nrog lub siab tawv, hnav tsis zoo thiab muaj kev siv me me, cov pwm kub yuav tsum ua kom muaj ntau dua ntxiv rau kev ua kom muaj crystallization. Nylon puab puab qhov kub yuav tsum muaj ntau dua, yog vim nws cov khoom lag luam tuab heev, pwm kub yog qhov kub tsawg dhau yuav ua rau muaj kev sib txawv sab hauv. Tsuas yog thaum cov pwm kub tau zoo tswj tau qhov loj me ntawm cov feem yuav ruaj khov.
Qhov ntsuas kub tswj tau ntau ntawm nylon pwm yog 20 ℃ ~ 90 ℃. Nws yog qhov zoo tshaj plaws kom muaj ob qho tib si txias (xws li kais dej) thiab cua sov (xws li ntsaws-hauv hluav taws xob cua kub pas nrig) ntaus ntawv.
Annealing thiab humidification
Txog kev siv ntsuas kub siab dua 80 ℃ lossis nruj ua ntej cov kev xav tau ntawm seem, tom qab molding yuav tsum muaj annealed hauv roj lossis paraffin. Qhov kev kub siab rau qhov kub yuav tsum yog 10 ℃ ~ 20 ℃ siab dua qhov kev pabcuam kub, thiab lub sijhawm yuav tsum muaj txog 10min ~ 60min raws li cov tuab. Tom qab annealing, nws yuav tsum tau txias maj mam. Tom qab annealing thiab kev kho cua sov, loj nylon crystal tuaj yeem tau txais, thiab cov rigidity tau txhim kho. Crystallized qhov chaw, qhov hloov ntom ntom yog me me, tsis yog deformation thiab tawg. Qhov chaw tsau los ntawm txoj kev txias txias muaj tsawg crystalloinity, me me siv lead ua, siab toductness thiab pob tshab.
Ntxiv rau tus neeg sawv cev nucileating ntawm nylon, txhaj tshuaj molding tuaj yeem tsim cov crystallity crystallinity, tuaj yeem ua kom lub voj voog loj, lub pob tshab thiab cov pob zeb ntawm cov ntu tau txhim kho.
Kev hloov pauv ntawm cov av noo noo tuaj yeem hloov qhov loj ntawm cov nylon pieces. Nylon nws tus kheej shrinkage tus nqi yog siab dua, nyob rau hauv thiaj li yuav tsum muaj qhov zoo tshaj plaws rau hauv paus rau, tuaj yeem siv dej lossis aqueous daws teeb meem ntub dej. Cov txheej txheem yog kom soak qhov chaw hauv dej npau npau lossis cov tshuaj potassium acetate thiab dej so) yog 1.25: 100, boiling potabium acetate ntawm cov chaw siab tshaj plaws ntawm cov chaw, 1.5mm 2h , 3 hli 8h, 6mm 16h. Kev kho cov tshuaj thoob noo tuaj yeem txhim kho cov qauv siv roj av ntawm cov yas, thiab txhim kho kev faib tawm sab hauv kev ntxhov siab, thiab cov nyhuv zoo dua li kev kho anealing.
Lub Sijhawm Post: 03-11-22