The thickener kwa lalabala utoto ayenera kukhala bwino ngakhale ndi emulsion polima pawiri, apo ayi ❖ kuyanika filimu adzakhala ndi pang'ono reticulate, ndipo adzatulutsa zosasinthika tinthu agglomeration, amene kuchepetsa mamasukidwe akayendedwe ndi coarsen tinthu kukula. The thickener adzasintha mlandu wa emulsion. Mwachitsanzo, cationic thickener adzakhala ndi zotsatira zosasinthika pa anionic emulsifier kuswa emulsion. Chothirira bwino cha utoto wa latex chiyenera kukhala ndi izi:
1. Mlingo wotsika komanso kukhuthala kwabwino
2. Kukhazikika kosungirako bwino, kutsika kwa viscosity chifukwa cha zochita za michere, komanso kuchepetsa kukhuthala chifukwa cha kusintha kwa kutentha ndi mtengo wa PH.
3, madzi posungira bwino, palibe zoonekeratu kuwira chodabwitsa
4. Palibe zotsatira zoyipa za filimu monga kukana scrub, gloss, kubisala mphamvu ndi kukana madzi.
5. Palibe pigment flocculation
Ukadaulo wokulirapo wa utoto wa latex ndi gawo lofunikira pakuwongolera mtundu wa latex ndikuchepetsa mtengo. Ma cellulose a Hydroxyethyl ndiwokhuthala bwino, omwe amakhala ndi zotsatira zambiri pakukula, kukhazikika komanso kusintha kwabwino kwa utoto wa latex.
Popanga utoto wa latex,hydroxyethyl cellulose (HEC)amagwiritsidwa ntchito ngati dispersant, thickener ndi pigment suspending agent kuti akhazikitse mamasukidwe akayendedwe a mankhwala, kuchepetsa agglomeration, kupanga utoto filimu yosalala ndi yosalala, komanso kupanga lalabala utoto cholimba. Rheology yabwino, imatha kupirira mphamvu zometa ubweya wambiri, ndipo imatha kuwongolera bwino, kukana kukanda komanso kufanana kwa pigment. Panthawi imodzimodziyo, HEC imakhala ndi ntchito yabwino kwambiri, ndipo utoto wa latex wokhuthala ndi HEC uli ndi pseudoplasticity, kotero njira zomangira monga kupukuta, kupukuta, kudzaza, ndi kupopera mbewu mankhwalawa zimakhala ndi ubwino wopulumutsa ntchito, osati zosavuta kuyeretsa ndi kugwedezeka, komanso kupukuta pang'ono. HEC ili ndi chitukuko chabwino cha mtundu. Ili ndi kusakanikirana kwakukulu ndi zopaka utoto zambiri ndi zomangira, zomwe zimapangitsa kuti zitheke kupanga utoto wa latex wokhala ndi mtundu wabwino kwambiri komanso wosasunthika. Kusinthasintha komwe kumagwiritsidwa ntchito popanga, ndi ether yopanda ionic. Chifukwa chake, itha kugwiritsidwa ntchito mumitundu yambiri ya pH (2 ~ 12), ndipo imatha kusakanikirana ndi zida zamtundu wa latex wamba monga ma pigment, zowonjezera, mchere wosungunuka kapena ma electrolyte.
Palibe zotsatira zoyipa pa filimu yokutira. Chifukwa yankho lamadzi la HEC lili ndi mawonekedwe owoneka bwino amadzi, sikophweka kutulutsa thovu panthawi yopanga ndi kumanga, ndipo chizolowezi cha maenje ophulika ndi ma pinholes ndi ochepa.
Kukhazikika bwino kosungirako. Pakusungirako kwa nthawi yayitali, dispersibility ndi kuyimitsidwa kwa pigment kumatha kusungidwa, ndipo palibe vuto la mtundu woyandama ndi kuphuka. Pakakhala madzi osanjikiza pang'ono pamtunda wa utoto ndi kutentha kosungirako kumasintha kwambiri. Kukhuthala kwake kudakali kokhazikika.
HEC imatha kukulitsa mtengo wa PVC (pigment volume concentration) mpaka 50-60%. Kuonjezera apo, topcoat thickener ya penti yochokera kumadzi ingagwiritsenso ntchito HEC.
Pakali pano, thickeners ntchito m'nyumba apamwamba kalasi latex utoto ndi kunja HEC ndi akiliriki ma polima (kuphatikizapo polyacrylates, homopolymer kapena copolymer emulsion thickeners a acrylic acid ndi methacrylic acid) thickeners.
Hydroxyethyl cellulose angagwiritsidwe ntchito
1. Monga dispersant kapena zoteteza guluu
Nthawi zambiri, HEC yokhala ndi viscosity ya 10 mpaka 30 mPaS imagwiritsidwa ntchito. HEC ya 300mPa · S ingagwiritsidwe ntchito pamodzi ndi anionic kapena cationic surfactants, ndipo zotsatira zobalalika zimakhala bwino. Nthawi zambiri, 0.05% ya kuchuluka kwa monomer.
2, ngati chowonjezera
Gwiritsani ntchito 15000mPa. Mlingo wotchulidwa wa high-viscosity HEC pamwamba pa s ndi 0.5 mpaka 1% ya chiwerengero chonse cha zokutira latex, ndipo mtengo wa PVC ukhoza kufika pafupifupi 60%. Mu utoto wa latex, HEC ya pafupifupi 20Pa,s imagwiritsidwa ntchito, ndipo mawonekedwe osiyanasiyana a utoto wa latex ndiwabwino kwambiri. Mtengo wongogwiritsa ntchito HEC pamwamba pa 30O00Pa.s ndi wotsika. Komabe, kusanja ndi mawonekedwe ena a utoto wa latex sizabwino. Kuchokera pakuwona zofunikira zamtundu ndi kuchepetsa mtengo, ndi bwino kugwiritsa ntchito masitayilo apakatikati ndi apamwamba HEC pamodzi.
3. Njira yophatikizira mu utoto wa latex
HEC yopangidwa ndi pamwamba imatha kuwonjezeredwa mu ufa wowuma kapena mawonekedwe a slurry. Ufa wouma umawonjezedwa mwachindunji ku pigment akupera. PH ya mfundo yowonjezera iyenera kukhala 7 kapena kutsika. Zigawo zamchere monga dispersants akhoza kuwonjezeredwa pambuyo paHECchanyowetsedwa ndi kumwazikana kwathunthu. Slurry yopangidwa ndi HEC iyenera kuphatikizidwa mu slurry pamaso pa HEC kukhala ndi nthawi yokwanira yothira madzi ndi kukhuthala ku chikhalidwe chosagwiritsidwa ntchito. HEC slurries imatha kukonzedwanso ndi glycol-based coalescing agents.
4. Anti-mildew wa utoto wa latex
HEC yosasungunuka m'madzi imawonongeka ikakumana ndi nkhungu zomwe zimakhala ndi cellulose ndi zotumphukira zake. Kuonjezera zotetezera kupenta kokha sikukwanira, zigawo zonse ziyenera kukhala zopanda ma enzyme. Magalimoto opangira utoto wa latex amayenera kukhala aukhondo, ndipo zida zonse ziyenera kuthiriridwa pafupipafupi ndi nthunzi 0.5% formalin kapena 0.1% mercury solution.
Nthawi yotumiza: Apr-25-2024