Apparatus for forming a thick-walled tubular product
AssigneePhillips Petroleum Company
InventorGuy E. Carrow
Life of this patent
Estimating the term…
Abstract
A mandrel and bushing sizing die assembly has an annulus formed between the mandrel and the bushing of the assembly for passing plastic material therethrough and forming a thick-walled tubular product. A middle portion of the annulus has a thickness in the range of about 25-50 percent of the greatest thickness of a first end portion of the annulus and the second, discharge end of the annulus has a thickness greater than about 1/4-inch and greater than the thickness of the middle portion of the annulus.
Claims4
An extrusion die assembly for forming a thick-walled tubular product, including a mandrel and bushing, said bushing having an axis and an opening extending therethrough for coaxially receiving said mandrel and said mandrel having an axis and a plurality of fluid pathways formed therethrough for passing a cooling fluid through the mandrel for cooling extrudate passing from an associated dynamic extruder through an annulus formed between said mandrel and said bushing, the improvement comprising:
- said annulus having first, middle and second portions, the first portion being located upstream with respect to the second portion, said middle portion of said annulus having a wall thickness in the range of 25 to 50 percent of the greatest wall thickness of said first portion of said annulus and said second portion of said annulus having a wall thickness greater than one-quarter and being greater than the wall thickness of said middle portion of said annulus, and
- at least a portion of said middle portion of said annulus and of said second end portion of said annulus are adjacent the fluid pathways formed through said mandrel.
Extrusion die assembly for use with an extruder comprising:
- a bushing;
- a mandrel inserted coaxially into said bushing to form an annulus having first, middle and second portions, said first portion being positionable adjacent to and downstream with respect to said extruder and said second portion being downstream with respect to said first portion, said middle portion of said annulus having a wall thickness in the range of 25 to 50 percent of the greatest wall thickness of said first portion of said annulus and said second portion of said annulus having a wall thickness greater than one-quarter inch and being greater than the wall thickness of said middle portion of said annulus, and
- cooling means associated with said mandrel adjacent said middle and said second end portions of said annulus for cooling material located within said middle and said second end portions of said annulus.
Dependencies are inferred from the claim text.