Cov hom tshuab molding

Yuav ua li cas los txhim kho qhov zoo ntawm nylon txhaj tshuaj molded qhov chaw?

Nylon kuj yog ib hom yas crystalline thiab muaj ntau tshaj 130 hom nylon sib txawv. Nylon 6, nylon 66, nylon 610, nylon 11, nylon 1010 thiab copolymer nylon, super tough nylon, iav fiber reinforced nylon, mineral reinforced nylon, thiab lwm yam yog siv rau hauv cov txheej txheem txhaj tshuaj molding. Yuav ua li cas txhim kho qhov zoo ntawm nylon txhaj tshuaj molding qhov chaw?
Cia peb los saib qhov kev qhia txogtshuab moulding tshuab hom.

I. Xyuas kom meej tias cov nyhuv qhuav
Nylon nqus tau cov dej noo yooj yim thiab yuav nqus tau cov dej noo hauv huab cua yog tias raug rau huab cua ntev. Yog tias cov dej noo ntau dhau raug nqus ua ntej txhaj tshuaj molding, qhov tsos thiab cov khoom siv kho tshuab ntawm qhov khoom yuav raug puas tsuaj.
Thaum kub tshaj qhov melting point (kwv yees li 254°C), cov dej molecules react nrog nylon. Cov tshuaj reaction no, hu ua hydrolysis lossis cracking, ua rau oxidation thiab discoloration ntawm nylon, txo qhov molecular mass ntawm cov resin thiab nws cov toughness, thiab nce fluidity. Qhov no tsis yog tsuas yog ua rau muaj teeb meem ua tiav, tab sis nws kuj tseem tuaj yeem ua rau kev ua haujlwm ntawm qhov khoom puas tsuaj. Cov nozzles salivated thaum lub sijhawm txhaj tshuaj molding thiab cov khoom muaj cov npoo ya hnyav.
Cov dej noo uas cov yas thiab cov pa roj nqus los ntawm qhov tawg, ua ke nrog cov khoom clamped, lub teeb nyob rau hauv qhov tsim ntawm qhov chaw tsis polished, cov kab nyiaj, cov pob, micropores, npuas, hnyav yaj nthuav dav tsis tuaj yeem tsim lossis molding tom qab lub zog kho tshuab txo qis.
Thaum kawg, tom qab qhov hydrolytic cracking ntawm nylon no, nws cov kev ua tau zoo yog irreducible kiag li, txawm tias nws yuav rov qhuav dua, nws tsis tuaj yeem siv dua.
Hauv kev xaus lus, qhov ziab ntawm cov khoom nylon ua ntej txhaj tshuaj molding yuav tsum tau coj mus rau hauv kev ua tib zoo, mus txog qhov twg nws yuav tsum tau ziab yog txiav txim siab los ntawm qhov yuav tsum tau ua ntawm cov khoom tiav, feem ntau qis dua 0.25%, zoo dua tsis pub ntau tshaj 0.1%, tsuav yog cov khoom siv raw tau qhuav zoo, txhaj tshuaj molding yooj yim, thiab cov khoom yuav tsis coj ntau yam teeb meem hauv qhov zoo.
Nylon zoo tshaj plaws kom qhuav hauv qab lub tshuab nqus tsev, vim tias qhov kub thiab txias ntawm kev ziab hauv huab cua siab, cov khoom siv raw uas yuav tsum tau ziab tseem muaj qhov ua tau ntawm kev oxidation thiab discoloration vim kev sib cuag nrog cov pa oxygen hauv huab cua, kev oxidation ntau dhau kuj tseem yuav tsim cov teebmeem rov qab, ua rau cov khoom tawg.
Yog tsis muaj cov khoom siv nqus tsev kom qhuav, tsuas yog siv lub tshuab ziab khaub ncaws uas muaj cua xwb thiaj siv tau, txawm hais tias qhov cuam tshuam tsis zoo. Muaj ntau yam kev ziab khaub ncaws uas muaj cua sib txawv, ntawm no yog ob peb yam xwb.

Thawj yog 60 ℃ ~ 70 ℃, cov ntaub ntawv txheej tuab 20 hli, ci 24 teev ~ 30 teev.
Qhov thib ob yog tsis pub tshaj 10 teev thaum ci hauv qab 90 ℃.
Qhov thib peb yog ci ntawm lossis qis dua 93 ° C rau 2 teev ~ 3 teev, vim tias qhov kub ntawm huab cua tshaj 93 ° C rau ntau dua 3 teev, muaj qhov ua tau ntawm kev hloov xim hauv nylon, yog li qhov kub yuav tsum tau txo qis rau 79 ° C.

Qhov thib plaub yog tsa qhov kub kom ntau dua 100 ℃, lossis txawm tias 150 ℃, qhov ntawd yog vim qhov kev xav ntawm nylon raug rau huab cua ntev dhau lossis los ntawm cov khoom siv ziab khaub ncaws khiav tsis zoo.
Qhov thib tsib yog kev ziab cua kub hauv lub raj mis rau cov tshuab txhaj tshuaj pwm, qhov twg qhov kub ntawm cov cua kub uas hla mus rau hauv lub raj mis raug tsa kom tsis pub tsawg dua 100 ° C lossis siab dua kom cov dej noo hauv cov yas qhuav. Tom qab ntawd cov cua kub raug nqa mus rau saum lub raj mis.
Cov xwm txheej ziab twg siv tau nyob ntawm seb qhov ziab zoo li cas. Qhov kub qis dhau ua rau lub voj voog ziab ntev thiab ua haujlwm tsis zoo; qhov kub siab dhau yuav ua rau cov yas sib sau ua ke lossis sib txuas, ua rau cov yas yaj viscosity ntau dua thaum lub sijhawm ua.
Lub tshuab nqus tsev dehumidifier yog ib lub qauv airtight uas rho tawm cov pa dej ntawm cov yas thaum ua kom sov sab hauv, yog li tsis tas yuav nce qhov kub kom qhuav tshwj xeeb, thiab lub sijhawm ziab tuaj yeem luv dua.
Yog tias cov yas qhuav tso rau hauv huab cua, nws yuav nqus cov dej noo sai sai hauv huab cua thiab qhov ua kom qhuav yuav ploj mus. Txawm tias nyob hauv lub raj npog, lub sijhawm khaws cia yuav tsum tsis txhob ntev dhau, feem ntau tsis pub tshaj 1 teev rau hnub los nag thiab txwv rau 3 teev rau hnub ci.

Ⅱ, tswj qhov kub ntawm lub thoob
Txawm hais tias qhov kub yaj ntawm nylon siab, thaum lub sijhawm yaj mus txog, nws cov viscosity qis dua li ntawm cov thermoplastics dav dav xws li polystyrene, yog li cov kua dej tsis yog teeb meem thaum tsim.
Tsis tas li ntawd xwb, vim yog cov khoom rheological ntawm nylon, qhov nrawm shear nce thaum qhov pom tseeb viscosity tsis poob qis, ua ke nrog qhov kub yaj yog nqaim, ntawm 3 ℃ ~ 5 ℃, yog li qhov kub siab ntawm cov khoom siv yog qhov lav ntawm kev du thiab du ntawm cov pwm.
Txawm li cas los xij, qhov ruaj khov thermal ntawm nylon nyob rau hauv lub xeev molten yog pluag, kev ua cov khoom kub dhau thiab lub sijhawm kub ntev dhau yuav ua rau cov polymers puas tsuaj, yog li ntawd cov khoom tshwm sim npuas, lub zog poob qis.

Yog li ntawd, qhov kub ntawm txhua ntu ntawm lub thoob yuav tsum tau tswj hwm nruj me ntsis kom cov khoom siv tau cua sov kom tsim nyog thiab sib npaug li sai tau ntawm qhov kub siab kom tsis txhob yaj tsis zoo thiab kub dhau hauv zos. Hauv cov txheej txheem tsim khoom, qhov kub ntawm lub thoob yuav tsum tsis pub tshaj 300 ° C thiab lub sijhawm cua sov ntawm cov pellets hauv lub thoob yuav tsum tsis pub tshaj 30 feeb.

Ⅲ, txhim kho cov khoom siv
Ua ntej tshaj plaws, thaum lub thoob, txawm hais tias muaj ntau cov khoom siv rau pem hauv ntej thaum txhaj tshuaj, tab sis cov khoom siv yaj hauv qhov ntsia hlau rov qab thiab xau ntawm qhov kawg ntawm qhov xov thiab phab ntsa sab hauv ntawm lub thoob inclined kuj nce ntxiv vim muaj cov kua dej ntau, qhov tshwm sim tsis yog tsuas yog txo qhov siab txhaj tshuaj zoo thiab qhov ntau ntawm cov khoom siv, thiab qee zaum kuj tiv thaiv kev nce qib ntawm kev ntxiv cov khoom siv, yog li ntawd cov ntsia hlau tsis tuaj yeem rov qab, yog li qhov kawg ntawm lub thoob yuav tsum muaj lub nplhaib kuaj xyuas kom tiv thaiv kev rov qab. Txawm li cas los xij, tom qab txhim kho lub nplhaib kuaj xyuas, qhov kub ntawm cov khoom siv yuav tsum tau nce ntxiv los ntawm 10 ℃ ~ 20 ℃ raws li, kom qhov poob siab tuaj yeem them rov qab.

Tom ntej no yog qhov xwm txheej ntawm lub nozzle, tom qab kev txhaj tshuaj tiav lawm thiab lub hau ntswj rov qab los, cov khoom siv molten hauv lub cub tawg pem hauv ntej yuav ntws tawm ntawm lub nozzle los ntawm nws tus kheej hauv qab qhov siab seem, uas hu ua "salivation phenomenon".
Yog tias cov khoom siv qaub ncaug nkag mus rau hauv qhov kab noj hniav, nws yuav ua rau qhov chaw uas cov khoom txias ua rau muaj qhov chaw lossis nyuaj rau sau, yog tias lub nozzle tawm tsam pwm ua ntej tshem tawm, thiab ua rau muaj teeb meem ua haujlwm ntau ntxiv, kev lag luam kuj tsis tsim nyog.
Ib lub nplhaib cua sov uas hloov tau nyias nyias ntawm lub nozzle yog ib txoj hauv kev zoo los tswj qhov kub ntawm lub nozzle, tab sis qhov kev daws teeb meem tseem ceeb yog hloov lub nozzle nrog lub caij nplooj ntoos hlav orifice nozzle uas muaj cov qauv tiv thaiv dej ntws.
Tau kawg, cov khoom siv caij nplooj ntoos hlav siv rau hauv cov nozzles no yuav tsum tiv taus qhov kub siab, txwv tsis pub nws yuav raug annealed ntau zaus hauv qab qhov kub siab vim yog qhov siab thiab poob ntawm elasticity.
Qhov thib plaub, kom ntseeg tau tias cov pwm tso pa tawm thiab tswj cov pwm kub
Vim tias nylon muaj qhov melting point siab, nws qhov freezing point kuj siab, thiab cov khoom molten yuav nkag mus rau hauv pwm txias txhua lub sijhawm vim tias qhov kub poob qis dua qhov melting point thiab solidification, tiv thaiv kev ua tiav ntawm kev sau, yog li yuav tsum siv kev txhaj tshuaj ceev ceev, tshwj xeeb tshaj yog rau cov khoom nyias nyias lossis cov khoom uas nyob deb ntawm cov khoom.
Tsis tas li ntawd xwb, kev sau pwm ceev ceev ua rau muaj teeb meem ntawm qhov cua nkag, cov pwm nylon yuav tsum muaj cov ntsuas cua nkag ntau dua.
Nylon xav tau qhov kub ntawm pwm siab dua li cov thermoplastics feem ntau. Feem ntau, qhov kub ntawm pwm siab yog qhov zoo rau kev ntws. Qhov no tseem ceeb heev rau cov khoom sib xyaw.

Qhov teeb meem yog tias qhov nrawm ntawm kev txias ntawm cov yaj tom qab sau lub qhov muaj qhov cuam tshuam rau cov qauv thiab cov khoom ntawm cov nylon. Crystallisation pib thaum nws nkag mus rau hauv lub qhov hauv lub xeev amorphous ntawm qhov kub siab, qhov nrawm ntawm crystallisation raug txwv los ntawm qhov kub pwm thiab qhov nrawm ntawm kev hloov pauv cua sov.
Thaum xav tau kom tau qhov ntev siab, pob tshab thiab tawv ntawm cov khoom nyias, qhov kub ntawm pwm yuav tsum qis, kom qhov degree ntawm crystallization txo qis; thaum xav tau kom tau qhov nyuaj siab, tiv taus hnav zoo, kev siv phab ntsa tuab deformation me me, qhov kub ntawm pwm yuav tsum siab, kom qhov degree ntawm crystallization nce ntxiv.
Nylon xav tau qhov kub pwm siab vim tias nws muaj qhov nrawm nrawm loj, thaum nws hloov ntawm lub xeev molten mus rau lub xeev khov, qhov ntim ntawm kev ntswj yog loj heev, tshwj xeeb tshaj yog rau cov khoom tuab-phab ntsa, qhov kub pwm qis dhau yuav ua rau muaj qhov khoob sab hauv. Tsuas yog thaum qhov kub pwm raug tswj tau zoo yog qhov loj ntawm qhov khoom ruaj khov dua.
Qhov kub thiab txias rau cov pwm nylon yog 20 ° C txog 90 ° C. Nws yog qhov zoo tshaj plaws kom muaj ob qho tib si txias (piv txwv li dej kais) thiab cua sov (piv txwv li cov cua sov hluav taws xob ntsaws).