The previous Study on the dynamic processing characteristics of co-rotating twin-screw extruder based on a visible technique (which employed a "transparent" extruder) performed by, the authors Wong et al. [1 and 2] had enabled a quantitative treatment to be carried out in the present paper on the melting behaviour of polymer during an extrusion process. The qualitative analysis performed previously [1] had led to the development of a melting model which was capable of revealing some of the fundamental melting behaviour The model also enabled the determination of the length of screw required for completing melting (Z(r)). Melting characteristics in terms of effects of solid feeding rate, temperature, screw speed and channel depth on the predicted Z(r) were discussed to further our understanding on melting performance of polymer melt in intermeshing corotating twin-screw extruder.