No solid bed extruder screw with varying width sub-channels

An extruder screw with a feed end spaced from a discharge end for use in a material extruder for processing a material to a molten state, the extruder screw comprising:

• a body extending along a longitudinal axis between the feed end and the discharge end, the body having an outer surface and including a transition section;
• a helical thread formed on the body, the helical thread having a pushing surface and a trailing surface;
• a channel for receiving the material to be processed, the channel defined by the outer surface of the body and an outer diameter of the helical thread bounded by the pushing surface and the trailing surface of the helical thread;
• wherein the channel in the transition section has a first sub-channel meeting a second sub-channel at a junction, the first sub-channel being closer to the feed end than the second sub-channel across a width of the channel;
• wherein the first sub-channel increases in width from a starting point in the channel to an ending point in the channel, the ending point being closer to the discharge end than the starting point;
• wherein the second sub-channel decreases in width from the starting point to the ending point;
• wherein the ending point is a first ending point, wherein the first sub-channel decreases in width from the first ending point to a second ending point in the channel closer to the discharge end than the first ending point;
• and
• wherein the second sub-channel increases in width from the first ending point to the second ending point.