Cov txheej txheem tsim khoom rau lub ntsej muag lub hauv paus feem ntau pib nrog cov khoom siv raw pretreatment. Cov roj theem muaj cov khoom xyaw xws li cov roj silicone, cov nroj tsuag -cov roj raws li, los yog hluavtaws esters, uas ua hauj lwm rau impart ib tug du zoo nkauj thiab ua kom seamless adherence rau ntawm daim tawv nqaij. Cov theem aqueous muaj xws li dej deionized, humectants (xws li glycerin thiab propylene glycol), thiab ntau yam khoom xyaw ua haujlwm. Cov khoom xyaw hmoov-xws li titanium dioxide thiab hlau oxides- tau txais kev kho dej ua ntej kom tiv thaiv kev sib sau ua ke thiab txhim kho kev tiv thaiv kev tiv thaiv.
Cov txheej txheem tom qab ntawd mus rau theem emulsification thiab dispersion. Tom qab cov roj thiab cov aqueous theem tau muab cais ua tiav raws li cov cua sov, lawv tau sib xyaw nrog cov khoom siv siab -shear emulsification los tsim cov qauv emulsion ruaj khov. Cov khoom xyaw hmoov yog maj mam qhia thaum lub sijhawm no, thiab cov khoom sib xyaw ua kom zoo dua ntxiv ntawm homogenization lossis peb - yob milling; qhov no ua kom lub hauv paus muaj qhov zoo, tsis yog -caking kev ntxhib los mos thaum tib lub sijhawm txhim kho qhov sib xws ntawm nws qhov kev pab cuam.
Cov theem kawg yuav tsum ua kom txias thiab kho cov qauv. Raws li lub kaw lus txias, cov tshuaj tsw qab, tshuaj tua kab mob, thiab cov khoom xyaw tshwj xeeb -xws li niacinamide lossis hyaluronic acid- tau ntxiv los ua kom cov khoom ruaj khov thiab txhim kho cov txiaj ntsig ntawm kev tu tawv nqaij. Tom qab homogenization, cov khoom tau ntim rau hauv ntim thiab raug kuaj xyuas kom ruaj khov (xws li kev tiv thaiv tshav kub, tiv thaiv txias, thiab centrifugation) kom paub tseeb tias nws tseem tsis muaj theem sib cais, roj exudation, los yog clumping nyob rau hauv ntau yam ib puag ncig, yog li yielding qhov kawg, npaj tau - rau - siv lub hauv paus khoom.