Patent ID: 6062719
Filing Date: 2000-05-16
Classification: B29C

Abstract:
A corotating multiple-screw extruder comprising first and second screws which are intermeshed, wherein(a) the first screw is comprised of first and second flights;(b) within a first segment of the first screw which has a longitudinal distance of at least one-half of a turn, both flights are continuous and the top of the first flight lies a radial distance of k away from the center axis of the first screw, the top of the second flight lies a radial distance of y away from the center axis of the first screw, and k is less than y;(c) the first screw further comprises a second segment within which both flights are continuous and the top of the first flight lies a radial distance of w away from the center axis of the first screw, the top of the second flight lies a radial distance of y away from the center axis of the first screw, and w is less than or equal to y;(d) the first segment of the first screw is paired with a first segment of the second screw;(e) the first segment of the second screw is comprised of first and second continuous flights, and, within said segment, the top of the first flight lies a radial distance of s away from the center axis of the second screw, the top of the second flight lies a radial distance of t away from the center axis of the second screw, and s is equal to t;(f) the second segment of the first screw is paired with a second segment of the second screw; and(g) the second segment of the second screw is comprised of first and second continuous flights, and, within said segment, the top of the first flight lies a radial distance of v away from the center axis of the second screw, the top of the second flight lies a radial distance of t away from the center axis of the second screw, and v is less than t.