Karfe foda samuwa a daban-daban barbashi girma dabam sanya daga daban-daban abubuwa, kamar nickel, chromium, silicon, Manganese yana da babban ƙarfi da kuma high sinadaran kwanciyar hankali a matsayin tace kafofin watsa labarai a lokacin aiwatar da polyester da polyamide yarn kadi.Yashin bakin karfe na Futai yana da ƙarin siffa mara kyau tare da ƙarin fasalulluka na saman don kamawa da kuma riƙe barbashi daga narkakkar polymer don rage toshewar spinnerets da karyewar yarn.
Zaɓin nau'ikan foda na bakin karfe don tacewa polymer yakamata suyi la'akari da dalilai kamar dacewa da kayan polymer, kewayon girman adadin da ake so, ingantaccen tacewa, da kowane takamaiman sinadarai ko buƙatun muhalli.