Lub thawv ua npuas ncauj yog ib lub thawv ntim ntim khoom ua los ntawm cov yas yas (ntau qhov hollow yas), thiab cov yas ua npuas ncauj yog cov yas uas muaj ntau qhov hws me me hauv. EPS foamed yas yog ib qho khoom siv hnyav ua los ntawm cov khoom ua npuas ncauj, uas yog tsim los ntawm polystyrene resin, foaming agent thiab lwm yam khoom siv. Nws yog ib qho tseem ceeb ntawm kev txuag hluav taws xob thiab txuag cov khoom siv rau cov nqaij nruab deg khov, khaws zaub, khaws cia txias, tsheb ciav hlau neeg caij tsheb thiab lwm yam.
