The physical and mathematical models of the pressure-induced melt removal melting process were established through the research on the polymer melting process in the VPCU of the vane extruder and the relationship between the solids conveying pressure and pressure-induced melt removal melting amount with the parameters were obtained. The solid compaction process was divided into the pre-compaction stage and the plastic-compaction stage. The pressure increased slowly in the pre-compaction stage and rapidly in the plastic-compaction stage. The pressure-induced melt removal melting amount was inversely proportional to the rotating speed

and was proportional to half a square of the diameter D of the stator

the quarter power of the pressure and the three-quarters power of the temperature Ts of the stator. The results showed that the predictions of the theoretical model were in good agreement with the experiments.