Taw qhia: Kev txhaj tshuaj molding yog thawj txheej txheem hauv cov khoom ntim khoom kom zoo nkauj. Thawj txheej txheem yog feem ntau txhaj tshuaj molding, uas ncaj qha txiav txim siab cov khoom zoo thiab cov khoom tsim tau. Kev teeb tsa ntawm kev txhaj tshuaj molding yuav tsum xav txog 7 yam xws li shrinkage, fluidity, crystallinity, tshav kub-rhiab plastics thiab yooj yim hydrolyzed plastics, kev ntxhov siab tawg thiab yaj tawg, thermal kev ua tau zoo thiab cua txias, thiab nqus dej noo. Kab lus no yog sau los ntawmshanghai zaj sawv pob. Qhia tawm cov ntsiab lus tseem ceeb ntawm 7 yam no, rau koj cov phooj ywg siv hauv kev xa khoom ntawm Youpin:
Txhaj tshuaj molding
Kev txhaj tshuaj molding, tseem hu ua kev txhaj tshuaj molding, yog ib txoj hauv kev molding uas ua ke nrog kev txhaj tshuaj thiab molding. Qhov zoo ntawm txoj kev txhaj tshuaj molding yog ceev ceev ceev, kev ua haujlwm siab, kev ua haujlwm tuaj yeem ua haujlwm tau, ntau yam xim, cov duab tuaj yeem yog los ntawm qhov yooj yim mus rau qhov nyuaj, qhov loj tuaj yeem yog los ntawm loj mus rau me me, thiab qhov loj ntawm cov khoom yog qhov tseeb, cov khoom yog ib qho yooj yim los hloov kho, thiab nws tuaj yeem ua rau hauv cov duab nyuaj. Qhov chaw thiab txhaj tshuaj molding yog tsim rau ntau lawm thiab molding ua teb xws li cov khoom uas muaj cov duab complex. Ntawm qhov kub thiab txias, cov khoom siv yas yaj tag nrho yog nplawm los ntawm cov ntsia hlau, txhaj rau hauv pwm kab noj hniav nrog kev kub siab, thiab txias thiab khov kom tau txais cov khoom pwm. Txoj kev no yog tsim rau huab hwm coj ntau lawm ntawm qhov chaw nrog cov duab complex thiab yog ib qho ntawm cov txheej txheem tseem ceeb.
01
Kev poob qis
Cov yam ntxwv cuam tshuam rau shrinkage ntawm thermoplastic molding yog raws li nram no:
1) Plastic hom: Thaum lub sij hawm molding txheej txheem ntawm thermoplastic plastics, tseem muaj cov ntim hloov pauv los ntawm crystallization, muaj zog nyob rau hauv kev ntxhov siab, loj residual kev nyuaj siab khov nyob rau hauv cov yas qhov chaw, muaj zog molecular orientation thiab lwm yam, yog li muab piv nrog thermoset plastics, shrinkage. tus nqi yog Loj, qhov shrinkage ntau yog dav, thiab cov directionality yog pom tseeb. Tsis tas li ntawd, qhov shrinkage tom qab molding, annealing los yog humidity txias yog feem ntau ntau dua li cov thermosetting yas.
2) Cov yam ntxwv ntawm cov khoom yas. Thaum cov khoom molten nyob rau hauv kev sib cuag nrog cov kab noj hniav, txheej txheej yog tam sim ntawd txias kom tsim ib tug tsawg-density khoom plhaub. Vim yog cov neeg txom nyem thermal conductivity ntawm cov yas, cov txheej hauv cov yas yog maj mam txias txheej nrog loj shrinkage. Yog li ntawd, phab ntsa thickness, qeeb txias, thiab high-density txheej thickness yuav shrink ntau.
Tsis tas li ntawd, muaj cov txheej txheem thiab cov txheej thiab kom muaj nuj nqis ntawm cov khoom ntws, kev faib tawm ntom ntom ntom thiab shrinkage tsis kam. Yog li ntawd, cov yam ntxwv ntawm cov khoom yas muaj kev cuam tshuam ntau dua rau kev shrinkage thiab directionality.
3) Xws li xws li daim foos, loj me, thiab faib cov khoom pub dawb cuam tshuam nrog cov khoom ntws, ntom sprution, siab ua haujlwm thiab lub sijhawm moulding. Direct feed ports thiab feed ports with large cross-sections (tshwj xeeb tshaj yog thicker cross-sections) muaj tsawg shrinkage tab sis ntau dua directivity, thiab luv feed ports nrog luv luv thiab ntev muaj tsawg directivity. Cov uas nyob ze rau qhov pub nkag los yog sib npaug rau cov kev taw qhia ntawm cov khoom ntws yuav ntsws ntau dua.
4) molding tej yam kev mob Cov pwm kub yog siab, cov khoom molten txias maj mam, qhov ceev yog siab, thiab lub shrinkage yog loj. Tshwj xeeb tshaj yog rau cov khoom siv crystalline, lub shrinkage yog ntau dua vim yog crystallinity siab thiab loj ntim hloov. Lub puab tsaig tso tawm kuj cuam tshuam nrog sab hauv thiab sab nraud txias thiab txawv txav ntawm cov yas thiab kev taw qhia ntawm cov shrinkage ntawm txhua feem.
Tsis tas li ntawd, tuav lub siab thiab lub sijhawm kuj muaj kev cuam tshuam ntau dua rau kev cog lus, thiab kev cog lus me me tab sis qhov kev taw qhia loj dua thaum lub siab siab thiab lub sijhawm ntev. Kev txhaj tshuaj siab yog siab, qhov sib txawv ntawm cov yaj viscosity yog me me, lub interlayer shear stress me me, thiab elastic rebound tom qab demolding yog loj, yog li lub shrinkage kuj yuav txo tau los ntawm tus nqi tsim nyog. Cov khoom kub yog siab, lub shrinkage yog loj, tab sis lub directionality yog me me. Yog li ntawd, kho cov pwm kub, siab, txhaj tshuaj ceev thiab lub sij hawm txias thaum lub sij hawm molding kuj tsim nyog hloov lub shrinkage ntawm yas ib feem.
Thaum tsim pwm, raws li qhov shrinkage ntau yam ntawm cov yas, phab ntsa tuab thiab cov duab ntawm cov yas, qhov loj thiab kev faib tawm ntawm daim ntawv inlet, tus nqi shrinkage ntawm txhua feem ntawm cov yas yog txiav txim siab raws li kev paub, thiab ces cov kab noj hniav loj yog xam.
Rau high-precision yas qhov chaw thiab thaum nws tsis yooj yim los tuav tus nqi shrinkage, cov hauv qab no yuav tsum tau siv feem ntau los tsim pwm:
Siv tus nqi me me rau cov kab uas hla sab nraud ntawm cov yas, thiab tus nqi qis dua rau lub puab txoj kab uas hla, thiaj li tawm hauv chav rau kev kho tom qab kuaj pwm.
Kev sim pwm txiav txim siab daim ntawv, qhov loj me thiab molding tej yam kev mob ntawm lub rooj vag system.
Cov khoom yas yuav tsum tau ua tiav tom qab ua tiav los txiav txim siab qhov hloov pauv loj (kev ntsuas yuav tsum yog 24 teev tom qab demolding).
Kho cov pwm raws li qhov tseeb shrinkage.
Rov ua cov pwm thiab tsim nyog hloov cov txheej txheem rau me ntsis hloov cov nqi shrinkage kom tau raws li qhov yuav tsum tau ua ntawm cov khoom yas.
02
fluidity
1) Lub fluidity ntawm thermoplastics feem ntau tuaj yeem txheeb xyuas los ntawm ntau qhov ntsuas xws li qhov hnyav molecular, yaj qhov ntsuas, Archimedes kauv ntws ntev, pom meej viscosity thiab ntws piv (cov txheej txheem ntev / cov phab ntsa tuab).
Me me molecular hnyav, dav molecular hnyav tis, tsis zoo molecular qauv tsis tu ncua, siab yaj Performance index, ntev kauv ntws ntev, tsis tshua muaj viscosity, siab flow ratio, zoo fluidity, plastics nrog tib lub npe khoom yuav tsum xyuas lawv cov lus qhia los txiav txim seb lawv fluidity yog. muaj feem xyuam rau kev txhaj tshuaj molding.
Raws li cov qauv tsim pwm, qhov fluidity ntawm cov khoom siv feem ntau tuaj yeem muab faib ua peb pawg:
Zoo fluidity PA, PE, PS, PP, CA, poly (4) methylpentene;
Nruab nrab fluidity Polystyrene series resin (xws li ABS, AS), PMMA, POM, polyphenylene ether;
Tsis zoo fluidity PC, tawv PVC, polyphenylene ether, polysulfone, polyarylsulfone, fluoroplastics.
2) Lub fluidity ntawm ntau yam yas kuj hloov vim muaj ntau yam molding yam. Lub ntsiab influencing yam yog raws li nram no:
① Cov khoom siv kub siab ua kom lub cev muaj zog, tab sis cov yas sib txawv muaj qhov sib txawv, xws li PS (tshwj xeeb yog cov muaj kev cuam tshuam siab thiab siab dua MFR tus nqi), PP, PA, PMMA, hloov polystyrene (xws li ABS, AS) fluidity ntawm, PC , CA thiab lwm yam yas sib txawv nrog qhov kub thiab txias. Rau PE thiab POM, qhov kub nce lossis txo qis tsis zoo rau lawv cov dej ntws. Yog li ntawd, tus qub yuav tsum tau kho qhov kub thiab txias thaum lub sij hawm molding tswj fluidity.
②Thaum lub siab ntawm kev txhaj tshuaj molding yog nce, cov khoom siv molten raug rau cov nyhuv shearing ntau dua, thiab cov fluidity kuj nce ntxiv, tshwj xeeb tshaj yog PE thiab POM rhiab heev, yog li kev txhaj tshuaj yuav tsum tau kho kom tswj tau qhov fluidity thaum molding.
③ Daim ntawv, qhov loj, layout, txias system tsim ntawm pwm qauv, ntws tsis kam ntawm cov khoom molten (xws li cov nto tiav, lub thickness ntawm cov channel seem, cov duab ntawm cov kab noj hniav, cov pa system) thiab lwm yam ncaj qha cuam tshuam cov khoom molten nyob rau hauv kab noj hniav Qhov tseeb fluidity nyob rau hauv, yog hais tias cov khoom molten yog txhawb kom txo qhov kub thiab nce lub fluidity kuj, lub fluidity yuav txo. Thaum tsim pwm, cov qauv tsim nyog yuav tsum raug xaiv raws li qhov fluidity ntawm cov yas siv.
Thaum lub sij hawm molding, cov khoom siv kub, pwm kub, txhaj tshuaj siab, txhaj tshuaj ceev thiab lwm yam tseem tuaj yeem tswj tau kom tsim nyog kho qhov ntim kom tau raws li cov kev xav tau molding.
03
Crystallinity
Cov thermoplastics tuaj yeem muab faib ua crystalline plastics thiab non-crystalline (tseem hu ua amorphous) plastics raws li lawv tsis muaj crystallization thaum lub sij hawm condensation.
Qhov tshwm sim hu ua crystallization yog hais txog qhov tseeb tias thaum cov yas hloov pauv los ntawm lub xeev molten mus rau lub xeev condensation, cov molecules txav ntawm nws tus kheej thiab tag nrho nyob rau hauv lub xeev tsis meej. Cov molecules nres txav mus los ntawm kev ywj pheej, nias ib qho chaw ruaj khov me ntsis, thiab muaj lub siab xav ua kom lub molecular kev npaj ua qauv tsis tu ncua. Qhov no tshwm sim.
Cov txheej txheem pom zoo rau kev txiav txim siab ob hom yas no tuaj yeem txiav txim siab los ntawm qhov pom tseeb ntawm cov yas tuab tuab. Feem ntau, cov ntaub ntawv crystalline yog opaque lossis translucent (xws li POM, thiab lwm yam), thiab cov ntaub ntawv amorphous yog pob tshab (xws li PMMA, thiab lwm yam). Tab sis muaj kev zam. Piv txwv li, poly(4) methylpentene yog cov yas crystalline tab sis muaj cov pob tshab siab, thiab ABS yog cov khoom siv amorphous tab sis tsis pob tshab.
Thaum tsim pwm thiab xaiv cov tshuab txhaj tshuaj molding, ua tib zoo saib xyuas cov cai hauv qab no thiab ceev faj rau cov yas crystalline:
Cov cua sov yuav tsum tau nce cov khoom kub mus rau qhov kub thiab txias yuav tsum muaj cua sov ntau, thiab cov khoom siv nrog lub peev xwm loj plasticizing yuav tsum tau ua.
Ib tug loj npaum li cas ntawm tshav kub yog tso tawm thaum lub sij hawm txias thiab reconversion, yog li nws yuav tsum tau txias txaus.
Qhov tshwj xeeb lub ntiajteb txawj nqus sib txawv ntawm lub xeev molten thiab cov khoom lub xeev yog loj, lub molding shrinkage yog loj, thiab shrinkage thiab pores yog nquag tshwm sim.
Ua kom txias ceev, tsis tshua muaj crystallinity, me me shrinkage thiab siab transparency. Lub crystallinity muaj feem xyuam rau cov phab ntsa thickness ntawm cov yas, thiab cov phab ntsa thickness yog qeeb kom txias, crystallinity siab, shrinkage yog loj, thiab lub cev muaj zog yog zoo. Yog li ntawd, cov pwm kub ntawm cov khoom siv crystalline yuav tsum tau tswj raws li qhov xav tau.
Lub anisotropy yog qhov tseem ceeb thiab kev ntxhov siab sab hauv yog loj. Molecules uas tsis crystallized tom qab demolding muaj ib tug nyiam mus txuas ntxiv mus crystallize, nyob rau hauv lub zog tsis txaus lub xeev, thiab yog nquag deformation thiab warpage.
Qhov kub ntawm crystallization yog nqaim, thiab nws yog ib qho yooj yim uas yuav ua rau cov khoom uas tsis muaj melted yuav tsum tau txhaj rau hauv pwm los yog thaiv qhov chaw nres nkoj pub.
04
Thaum tshav kub kub-rhiab plastics thiab yooj yim hydrolyzed plastics
1) Thaum tshav kub kub rhiab heev txhais tau hais tias ib co plastics yog rhiab heev rau tshav kub. Lawv yuav tau rhuab rau ib lub sij hawm ntev ntawm qhov kub thiab txias los yog qhov chaw pub qhib me me dhau. Thaum cov nyhuv shearing loj, cov khoom kub yuav nce tau yooj yim ua rau discoloration, degradation thiab decomposition. Cov yam ntxwv yas yog hu ua cov yas uas muaj cua sov.
Xws li tawv PVC, polyvinylidene chloride, vinyl acetate copolymer, POM, polychlorotrifluoroethylene, thiab lwm yam. Thaum tshav kub kub-rhiab plastics tsim monomers, gases, khib nyiab thiab lwm yam by-products thaum decomposition. Tshwj xeeb, qee cov roj decomposition muaj qhov khaus, corrosive lossis tshuaj lom rau tib neeg lub cev, khoom siv, thiab pwm.
Yog li ntawd, yuav tsum tau them nyiaj mloog mus rau pwm tsim, txhaj tshuaj molding tshuab xaiv thiab molding. Cov ntsia hlau txhaj tshuaj molding tshuab yuav tsum tau siv. Cov seem ntawm cov txheej txheem pouring yuav tsum loj. Cov pwm thiab lub thoob yuav tsum yog chrome-plated. Ntxiv stabilizer kom tsis muaj zog nws cov thermal rhiab heev.
2) Txawm tias qee cov yas (xws li PC) muaj cov dej me me, lawv yuav decompose nyob rau hauv qhov kub thiab txias. Cov cuab yeej no hu ua yooj yim hydrolysis, uas yuav tsum tau rhuab thiab qhuav ua ntej.
05
Kev ntxhov siab tawg thiab tawg tawg
1) Qee cov plastics yog rhiab heev rau kev ntxhov siab. Lawv yooj yim rau kev ntxhov siab sab hauv thaum molding thiab yog nkig thiab yooj yim tawg. Cov khoom yas yuav tawg nyob rau hauv qhov kev txiav txim ntawm sab nraud quab yuam los yog hnyav.
Vim li no, ntxiv rau ntxiv cov khoom siv ntxiv rau cov khoom siv raw los txhim kho cov kab nrib pleb, kev saib xyuas yuav tsum tau them rau ziab cov ntaub ntawv raw, thiab cov pwm pwm yuav tsum tau xaiv kom tsim nyog los txo cov kev ntxhov siab sab hauv thiab ua kom tawg tsis kam. Thiab yuav tsum xaiv qhov tsim nyog ntawm cov khoom yas, nws tsis tsim nyog rau kev teeb tsa thiab lwm yam kev ntsuas kom txo qis kev ntxhov siab.
Thaum tsim cov pwm, lub demolding lub kaum sab xis yuav tsum tau nce, thiab yuav tsum tau xaiv ib tug tsim nyog feed inlet thiab ejection mechanism. Cov khoom siv kub, pwm kub, txhaj tshuaj siab thiab lub sijhawm txias yuav tsum tau hloov kho kom tsim nyog thaum lub sij hawm molding, thiab sim kom tsis txhob demolding thaum cov yas yog txias heev thiab nkig, tom qab molding, cov yas qhov chaw yuav tsum tau mus rau tom qab kho kom zoo. tawg tsis kam, tshem tawm cov kev ntxhov siab sab hauv thiab txwv tsis pub kev sib cuag nrog cov kuab tshuaj.
2) Thaum lub polymer yaj nrog qee qhov dej ntws ntws dhau los ntawm lub qhov taub ntawm qhov kub thiab txias thiab nws cov nqi ntws ntau tshaj li ib qho nqi, pom tseeb ntawm cov kab nrib pleb ntawm cov yaj yog hu ua cov pob txha tawg, uas yuav ua rau cov tsos mob thiab lub cev muaj zog ntawm cov khoom yas. Yog li ntawd, thaum xaiv cov polymers nrog siab yaj ntws tus nqi, qhov cross-section ntawm nozzle, khiav, thiab pub qhib yuav tsum tau nce ntxiv kom txo tau qhov kev txhaj tshuaj ceev thiab nce cov khoom kub.
06
Thermal kev ua tau zoo thiab txias tus nqi
1) Ntau yam yas muaj qhov sib txawv thermal xws li cov cua sov tshwj xeeb, thermal conductivity, thiab kub distortion kub. Plasticizing nrog cov cua kub tshwj xeeb yuav tsum muaj cua sov ntau, thiab siv lub tshuab txhaj tshuaj molding nrog lub peev xwm loj yas yuav tsum tau siv. Lub sij hawm txias ntawm cov yas nrog kub kub distortion kub yuav luv luv thiab demoulding yog ntxov, tab sis qhov txias deformation yuav tsum tau tiv thaiv tom qab demolding.
Cov yas uas muaj cov thermal conductivity tsawg muaj qhov txias txias (xws li ionic polymers, thiab lwm yam), yog li lawv yuav tsum tau txias txaus los txhim kho cov cua txias ntawm pwm. Kub khiav pwm yog tsim rau cov yas uas tsis tshua muaj cua sov thiab siab thermal conductivity. Cov yas uas muaj cov cua kub tshwj xeeb loj, tsis muaj thermal conductivity, thermal deformation kub tsis tshua muaj, thiab qis qis qis tsis haum rau kev kub ceev molding. Tsim nyog txhaj tshuaj molding tshuab thiab txhim kho pwm txias yuav tsum tau xaiv.
2) Ntau yam yas yuav tsum tau tswj kom muaj qhov tsim nyog txias raws li lawv hom, yam ntxwv thiab cov duab ntawm cov khoom yas. Yog li ntawd, cov pwm yuav tsum tau nruab nrog cua sov thiab cua txias tshuab raws li molding yuav tsum tau kom muaj ib tug tej yam pwm kub. Thaum cov khoom kub nce pwm kub, nws yuav tsum tau txias kom tiv thaiv cov yas los ntawm deforming tom qab demolding, shorten lub voj voog molding, thiab txo cov crystallinity.
Thaum cov yas khib nyiab cua sov tsis txaus kom cov pwm ntawm qhov kub thiab txias, cov pwm yuav tsum tau nruab nrog lub tshuab cua sov kom cov pwm ntawm qhov kub thiab txias los tswj cov cua txias, xyuas kom muaj dej ntws, txhim kho cov khoom ntim lossis tswj cov yas. qhov chaw kom txias maj mam. Tiv thaiv kom tsis txhob muaj qhov txias txias sab hauv thiab sab nraud ntawm cov phab ntsa tuab tuab thiab ua kom muaj crystallinity.
Rau cov neeg uas muaj fluidity zoo, loj molding cheeb tsam, thiab cov khoom tsis sib xws, nyob ntawm seb cov molding tej yam kev mob ntawm cov yas, tej zaum nws yuav tsum tau rhuab los yog txias alternated los yog hauv zos rhuab thiab txias. Txog qhov kawg no, cov pwm yuav tsum tau nruab nrog cov cua txias los yog cua sov.
07
Hygroscopicity
Vim hais tias muaj ntau yam additives nyob rau hauv plastics, uas ua rau lawv muaj ntau theem ntawm affinity rau ya raws, plastics yuav roughly muab faib ua ob hom: ya raws, noo noo adhesion, thiab tsis-absorption thiab tsis-stick ya raws. Cov ntsiab lus dej hauv cov khoom yuav tsum tau tswj nyob rau hauv qhov kev tso cai. Txwv tsis pub, cov dej noo yuav dhau los ua roj lossis hydrolyze nyob rau hauv qhov kub thiab txias, uas yuav ua rau cov resin ua npuas dej, txo cov kua dej, thiab muaj qhov tsis zoo thiab cov khoom siv kho tshuab.
Yog li ntawd, hygroscopic plastics yuav tsum tau preheated nrog cov cua kub uas tsim nyog thiab cov kev qhia tshwj xeeb raws li qhov yuav tsum tau ua kom tsis txhob rov nqus dej noo thaum siv.
Shanghai Rainbow Industrial Co., Ltd yog cov chaw tsim tshuaj paus, Shanghai zaj sawv pob Muab ib-stop cosmetic ntim.Yog tias koj nyiam peb cov khoom, koj tuaj yeem tiv tauj peb,
Lub Vev Xaib:www.rainbow-pkg.com
Email:Bobby@rainbow-pkg.com
WhatsApp: + 008613818823743
Post lub sij hawm: Sep-27-2021