Imyenda ya PU ni polyurethane, ikozwe cyane cyane muri fibre fibre fibre igizwe, ifite ibintu bisa nimpu nyazo, gride yimyenda ihendutse, ikoreshwa ryinshi.Bitewe nibintu rusange byoroheje byimyenda ya pu, birashobora kuba byiza cyane kwirinda kwangirika kwamazi, kandi ingaruka zayo zo gufata amazi nibyiza cyane.Nyuma yo gukuramo amazi, ntihazabaho kubyimba cyangwa guhinduka.Igihe kimwe, biroroshye cyane kubyitaho.Nkuruhu, impumuro iroroshye kandi igiciro kirahendutse.