Haɗaɗɗen yumbu roba sa farantin.
Kyakkyawan juriya na lalacewa, rayuwar lalacewa na yumbu alumina mai tsayi yana kusan.Masu ƙidayar lokaci 5 sun fi roba tsayi kuma sau 10 fiye da karfe.
Ƙarin juriya mai tasiri, roba ko matashin polyurethane yana ƙara juriya mai tasiri.
Akwai shi cikin sifofi da girma dabam.