摘要 |
The hopper of a screw communicates with a feed chamber situated upstream from the extruder cylinder. The substantially rectangular feed chamber is large enough so that the behavior of a mass of plastic material in its initial state, i.e., in the form of powder or pellets, is affected neither by the side-walls nor by the upper wall nor by the removable bottom of the chamber. Thus, in the case of pellets, the distance between any of those walls and the apex of the screw thread is appreciably greater than the average diameter of the pellets. |