txheej yog xim fluorocarbon los yog glassy polymer, ob qho tib si hauv cov xim pleev xim rau cov txheej txheem kev tiv thaiv, cov khoom tsim yog yooj yim heev, xim muaj peev xwm ua tau yam tsis muaj kev kho polishing, tau kawg, kev tsim kho yuav zoo dua tom qab txoj kev kho polishing tiv thaiv cov xim muaj yees thaum txog 1-6 lub hlis.
Zoo: Feem ntau cov khoom muaj nyob hauv cov dej, yooj yim rau khoom, yooj yim rau txua.
Disadvantages: kev lag luam tus nqi ntau dua chaos (vim hais tias nws yog soluble hauv dej los yog lwm cov kuab tshuaj, vim qhov sib txawv thiab qhov sib txawv ntawm cov nqi sib txawv)