Separation-type screw for extruder

The utility model discloses a separation-type screw for an extruder. The separation-type screw comprises a feeding section, an extrusion section and a discharging section, wherein constant depth equidistant threads are formed in the feeding section and the discharging section; a gradient equidistant invariable depth thread is formed in the extrusion section; the depth of the thread in the extrusion section is sequentially decreased from the feeding section to the discharging section. According to the separation-type screw for the extruder, the screw is divided into the feeding section, the extrusion section and the discharging section, and the threads with different spaces and depths are formed in different sections of the screw, so that the separation-type screw can be applied to the extrusion production of multiple rubber materials, and the extrusion yield can be increased under the condition of ensuring the quality of extruded products; moreover, the requirements of a PVC (Polyvinyl Chloride) material on double threads of the screw are met by the BM section, and the compression ratio reaches 1:1.22.