Wet Type Double Screw Extruder. HAIYAUN Steam type twin screw extruder can make kinds of feed, such as dog, catfish, shrimps, crab, etc. the fish pellet made by the machine can float on water more than 24 hours. Gelatinization degree can reach 90%, enhance the output of fodders, it is suitable for making floating feed, pet food, fish fodder.