PU ndiye chidule cha Polyurethane, ndipo dzina lake lachi China ndi Polyurethane.
Phala lovala limapangidwa makamaka ndi kuthandizira (tepi yamapepala), pad mayamwidwe ndi pepala lodzipatula, logawidwa m'mitundu khumi molingana ndi makulidwe osiyanasiyana.Chogulitsacho chizikhala chosabala.
Band-aid ndi tepi yayitali yomwe imayikidwa ndi yopyapyala yamankhwala pakati, yomwe imayikidwa pabalapo kuti iteteze bala, kuyimitsa magazi kwakanthawi, kukana kusinthika kwa bakiteriya ndikuteteza bala kuti lisawonongekenso.
Mankhwalawa amapangidwa ndi nsalu zopanda nsalu zachipatala, 70% mowa wamankhwala.