A new kinematic model of the screw-based plastifying system
Polimery 2000, No 4, 264
SummaryThe present kinematic concept assumes both the barrel and the screw to move uniformly but in opposite directions (Fig. 1). Equations 13, 14 and 15 were derived to describe the longitudinal flow, drag flow and pressure flow, resp., and equation 26 to describe the volume flow rate. The equations were verified (Table 1, 2; Fig. 3) and the plastifying system processes were thus discovered to have been intensified whereby the volume flow rates of the drag flow and leak flow and also the velocities and rates of the pressure flow have increased. As a result, the total volume flow rate is higher than that in the model with the revolving barrel and that in the model with the revolving screw. In the example considered the corresponding increases are 245% and 298% under identical conditions. The concept and design assumptions are presented, based on the new model, and a suitable modification of the plastifying system is suggested.