Igama eliqhelekileyo leenkqubo zokutofa ezisebenzisa izisombululo zeekhemikhali ezikhethekileyo zokuphucula ukubuyiswa kwe-oyile, ukususa umonakalo owenziweyo, ukucoceka kwe-perforations evaliweyo okanye iileya zokwakheka, ukunciphisa okanye ukuthintela ukubola, ukuphucula i-oyile ekrwada, okanye ukulungisa imiba yokuqinisekisa ukuhamba kweoli ekrwada.Isitofu sinokuqhutywa ngokuqhubekayo, kwiibhetshi, kwimingxuma yokutofa, okanye ngamanye amaxesha kwimithombo yemveliso.