Manufacture of composite screw rotors for air compressors by RTM process

Screw rotors, the key parts of screw compressors, are widely used in compressing air and refrigerant due to their high productivity, compact size, low noise and easy maintenance. In general, a screw compressor unit is composed of female and male rotors of complex geometric shape. The manufacturing cost and time of the screw rotors are high because the complicated helical shapes of the screw rotors are manufactured usually by dedicated machine tools. In this study, to reduce the production cost and weight of screw rotors, the screw rotors for air compressors were manufactured with chopped carbon fiber epoxy composite materials by the RTM (resin transfer molding) process using separable four-piece molds for easy demolding of helical shape screw rotors.