Taw qhia rau dispersibility ntawm pigments
Pigments yog insoluble particles uas yog tsim thiab tsim los faib xim rau cov ntaub ntawv. Kuj hu ua colorants, lawv feem ntau muab faib ua ob hom - organic thiab inorganic.
Pigments yuav tsum tau ntub dej kom zoo, de-agglomerated los yog dispersed, uniformly faib, thiab stabilized kom muaj xim zoo siv, zais zog, thiab gloss. Nws xav tau lub sijhawm thiab lub zog kom ruaj khovpigment dispersion.
Colorants twb dispersed muaj ib tug muaj zog xav tau rov qab mus rau lawv qub agglomerated xeev. Qhov kev xav tau muaj zog no ua rau nws yog ib qho tseem ceeb los xaiv tus neeg sawv cev ntub dej thiab cov khoom tawg kom tau txais cov qauv ruaj khov.
Wetting additives los yog surfactants, feem ntau hu ua amphiphilic chemistry, muaj qhov hnyav molecular tsawg thaum dispersing additives lossis oligomers stabilize cov xim. Qhov no stabilization zam re-agglomeration.
Yuav ua li cas disperse thiab stabilize pigments nyob rau hauv peb kauj ruam
Wetting
Rau cov xim kom ntub dej kom zoo, koj yuav tsum pauv cov huab cua / khoom sib txuas rau cov kua / khoom. Kev ntub dej yuav ua tau zoo dua yog tias tsis muaj cua nkag hauv qhov system. Yog li, koj nkag siab tias nws yog txhua yam hais txog qhov nro saum npoo. Qhov nro saum npoo yuav tsum qis dua rau cov kua kom ntub cov khoom.
Yog li, cov kua dej uas muaj qhov nro qis dua yog qhov ua tau zoo hauv kev ntub dej, uas yog vim li cas cov khoom ntub dej ntxiv yog qhov tseem ceeb heev rau tus qauv. Wetting additives txo qhov nro saum npoo, yog li adhering rau saum npoo thiab txheej xim los tsim cov kua interface.
Feem ntau, cov kuab tshuaj raws li cov txheej txheem ntub cov xim ntau dua vim lawv qhov qis qis ntawm cov kuab tshuaj thaum piv nrog cov dej uas muaj qhov nro ntau dua. Dhanveen Pigments, yog ib lub tuam txhab loj tshaj plaws ntawmxim ntsuab 7, muab qhov zoo tshaj plaws dispersant.
Deagglomeration
Nyob rau hauv lub deagglomeration theem ntawm dispersion txheej txheem, cov pigment agglomerates muab faib ua thawj hais thiab me aggregates. Qhov tsawg dua qhov nro ntawm lub tsheb uas cov xim sib xyaw ua ke, lub zog tsawg dua yuav tsum tau ua kom tawg cov xim. Lub deagglomeration theem yog attained los ntawm kev siv txhua yam zog tsim los ntawm high-speed dispersers thiab lwm yam khoom sib tsoo.
Cov ncej ntawm lub tshuab hluav taws xob sib xyaw ua ke nrog Cowles hniav zoo disperses cov xim. Cowles hniav nrog siab shear hniav yog zoo heev rau dispersion ntawm pigments. Lwm yam ntawm cov hniav, xws li cov hniav sib xyaw lossis cov hniav siab, kuj tuaj yeem siv nyob ntawm qhov viscosity ntawm qhov tawg. Tsis tas li, nws nyob ntawm qhov yuav tsum tau sib tov lossis txav cov khoom siv raw thaum lub sijhawm ua haujlwm.
Txhawm rau kom ua tiav qhov zoo ntawm laminar ntws thiab txhim kho qhov ua tau zoo ntawm kev tawg, nws tau pom tias txoj kab uas hla ntawm cov hniav yog 1/3rd ntawm lub tank txoj kab uas hla. Tsis tas li ntawd, cov hniav yuav tsum yog 0.5 rau 1.0 diameters tawm ntawm lub tank hauv qab. Nws feem ntau pom zoo tias qhov ceev ceev rau lub kaw lus nruab nrab ntawm viscosity ntawm 70-100 Krebs unit yuav tsum nyob ib ncig ntawm 4000-6000 fpm. Koj tuaj yeem siv qhov sib npaug - Ncej RPM x 0.262 x hniav txoj kab uas hla los txiav txim qhov ceev ntawm lub taub. Pigments nrog ib qho kev ntxhib los mos tuaj yeem tawg tau zoo siv lub tshuab xov xwm. Nws tsim cov shear ntau dua, xws li ntsug, kab rov tav, thiab pob tawb mills. Yog hais tias koj xav kom disperse cov xim mus rau ib tug nano theem, nws yog pom zoo kom siv 0 3-0.5 sib tsoo xov xwm.
Stabilization
Cov xim uas tam sim no deagglomerated yuav tsum tau stabilized los tiv thaiv nws los ntawm re-agglomeration. Nyob rau hauv cov txheej txheem stabilization, dispersants yog ntxiv uas yuav absorbed los ntawm cov pigment hais thiab kom lawv detached. Feem ntau, qhov no yog li cas tusdispersion ntawm pigments hauv plasticssiv qhov chaw.
Pigments nyob rau hauv ncua kev kawm ntawv yuav stabilized tog twg los - electrostatically los yog sterically.
Electrostatic Dispersants
Electrostatic dispersants muaj cov nqi ionic hauv lawv. Kev sib cuam tshuam nrog cov xim pleev xim rau saum npoo yuav pab tsim cov khoom zoo li-them, feem ntau cationic. Qhov zoo li tsub rau ntawm qhov chaw ntawm cov khoom sib sib zog nqus, yog li ua kom cov xim nyob rau hauv qhov kev ncua ruaj khov. Txawm li cas los xij, ntxiv cov khoom siv ionic thiab kev hloov pauv hauv qib pH tuaj yeem txo qhov kev ruaj ntseg ntawm cov khoom raug tshem tawm nrog electrostatic dispersants.
Steric Dispersants
Lawv yog ua los ntawm cov molecules uas muaj ib tug anchoring lub taub hau pab pawg neeg attracted rau cov xim hais thiab tails ntawm lub kua theem ntawm dispersion. Steric stabilization yog unbelievably ruaj khov nyob rau hauv ib tug dav pH ntau yam thiab nyob rau hauv siab ntsev concentrations.
Pigment Wetting Agents & Dispersants: Vim li cas lawv tseem ceeb?
Feem ntau, cov khoom kim tshaj plaws nyob rau hauv cov xim, number case, los yog txheej txheej yog pigments. Optimizing pigment wetting thiab dispersion nyob rau hauv formulation yog ib qho tseem ceeb los xyuas kom meej pom kev pom thiab lub cev lub cev. Thaum koj xaiv qhov tseeb dispersant thiab wetting tus neeg sawv cev rau formulation, nws ua tau zoo inks, coatings, thiab xim, thaum tus nqi ntawm ntau lawm mus rau qhov tsawg kawg nkaus.
Thaum cov pigments qhuav, lawv nyob rau hauv daim ntawv ntawm agglomerates loj nyob rau hauv ntau qhov ntau thiab tsawg. Los ntawm dispersing lawv nyob rau hauv ib tug ua kua nruab nrab, lub zog yog muab rau cov agglomerates kom txo lawv qhov loj me rau aggregates thiab txo qhov ntau ntawm aggregate qhov ntau thiab tsawg. Qhov no pab tau ntau txoj hauv kev, xws li -
Nyob rau hauv ib homogenous ncua kev kawm ntawv, dispersion muab stability rau hais.
Nws txwv tsis pub cov khoom nyob rau hauv cov kua nruab nrab.
Nws txhim khu kev ua haujlwm ntawm cov xim.
Nws pab tsim cov xim rov tsim dua thiab twv tau.
Pigments ua lub luag haujlwm tseem ceeb hauv kev tsim thiab tinting plastics thiab coatings thiab ua lub luag haujlwm tseem ceeb hauv lawv qhov kev ua tau zoo; Nws yog li tseem ceeb kom paub lawv txoj kev dispersion.