The pretreatment muitiro adopts idzva zvakatipoteredza noushamwari asiri chepfu silane, inova pamusoro kwezvakatipoteredza kuchengetedzwa kurapwa kwacho muindasitiri. Ukobvu hwekuputira kwepamusoro ndeye 50 ~ 80 μm, inotsvedzerera, kupokana kwekukwikwidza kwekoramu yekusimudza idiki, uye kusimudza kwakatsiga.