The invention relates to a hollow single screw extruder with spiral grooves in double sides. The hollow single screw extruder comprises a motor, a transmission mechanism, a base, a radial
thrust bearing pack, a
machine barrel, a hollow screw, an
electric heating coil, an extruder head, a hopper, a gear and a central shaft. The motor drives the hollow screw to rotate through the transmission mechanism and the gear, and the extruder head is arranged at the
discharge end of the
machine barrel. The hollow single screw extruder is characterized in that the hollow screw is located in the
machine barrel, and the central shaft is located in the hollow screw; the hollow screw is coaxial with the machine barrel and the central shaft and can rotate relative to the machine barrel and the central shaft; the outer spiral groove is formed in the outer
circular surface of the hollow screw, and the inner spiral groove is formed in an inner circular hole of the hollow screw; a first
discharge outlet and a second
discharge outlet of the hopper are communicated with the left end of the inner spiral groove and the left end of the outer spiral groove respectively, and the right end of the outer spiral groove and the right end of the inner spiral groove are communicated with the extruder head. According to the hollow single screw extruder provided with the hollow screw, the length of the screw can be greatly reduced, the requirement of a material
extrusion molding process for the relative length of a flow channel of the screw can be met sufficiently, the
residence time of materials in the spiral grooves is shortened,
decomposition of the high
molecular materials is reduced, and product quality is guaranteed; besides, the service life of the machine can be prolonged, the productivity of the machine can be improved significantly, and the heat efficiency is improved.