Extruder
AssigneeMars, Incorporated
InventorsKarina Wehrle, Christopher Abbott, Kamyar Nabavi, Peter Gibbs
Life of this patent
Estimating the term…
Abstract
An extruder 10 comprises a barrel 12 and a screw 24 mounted in the barrel for rotation. The screw comprises screw threads 26a, 26b, 26c. The barrel has an inlet funnel 22 toward one end for material to be extruded and a die plate 18 with openings 20 at the other end and an air inlet port 28 toward one end of the barrel and an air outlet port 30 toward the other end. The screw threads are such that material 34 in the barrel is moved more quickly along the portion of the barrel between the air inlet port and the air outlet port than upstream of that portion. The air outlet is connected to a pump 32 so that there is a pressure difference between the air inlet and the air outlet.
Claims4
An extruder comprising:
- a barrel and a screw mounted in the barrel for rotation, the screw comprising screw elements and the barrel comprising:
- an inlet toward one end for material to be extruded and an outlet for the material toward the other end;
- and a fluid inlet and a fluid outlet in the barrel wall, the fluid inlet and the fluid outlet being separated along the barrel wall in the longitudinal direction thereof and the screw elements either having i) a wider pitch or ii) a screw axle of smaller diameter for that portion of the screw between the fluid inlet and the fluid outlet than both upstream and downstream of the said portion, one of the fluid inlet and the fluid outlet being connected to a pump so that there is a pressure difference between the fluid inlet and the fluid outlet, wherein the fluid outlet is closer to the material outlet than is the fluid inlet.
Dependencies are inferred from the claim text.