Back to results
US 6,474,973 B2Granted
Extruder die head
AssigneeWindmoeller & Hoelscher KG
InventorsHans-Udo Beckmann, Juergen Linkies, Dieter Aus Dem Moore
Life of this patent
Estimating the term…
Loading patent…
Loading patent…
AssigneeWindmoeller & Hoelscher KG
InventorsHans-Udo Beckmann, Juergen Linkies, Dieter Aus Dem Moore
Estimating the term…
An extruder die head, preferably a blown film head, has an internal cylindrical mandrel and a cylindrical jacket, which envelops concentrically the mandrel. Between the mandrel and jacket an annular channel is formed that empties into a die slit. At least one melt-supplying line empties into the annular channel in the area opposite the die slit. To avoid slits between the central mandrel and the jacket, enveloping the mandrel, where the polymer melt can accumulate and deposit, the mandrel is made as one piece with a flange-like foot and is provided in the area, adjacent to the foot, with at least one borehole, which feeds in the melt. On the mandrel adjacent to the foot is shrunk a ring, which seals the slit between both the mandrel and jacket. The cylindrical jacket is mounted above and connected sealingly to the shrunk-on ring to form the annular channel.
An extruder die head, having an internal cylindrical mandrel and a cylindrical jacket, which envelops concentrically said mandrel, an annular channel formed between said mandrel and said jacket for emptying into a die slit, and at least one borehole, which feeds a melt into said annular channel in an area opposite said die slit, the improvement comprising:
An extruder die head, comprising:
A blown film extrusion die head which comprises an internal cylindrical mandrel and a cylindrical jacket which concentrically envelops said mandrel and defines an annular channel between said mandrel and said jacket which empties into a die slit, said mandrel being made as one piece with a flange-shaped foot and provided with at least one borehole which feeds in melt into said annular channel, and a ring shrunk onto said mandrel adjacent to said foot which seals an initial region of said mandrel, said cylindrical jacket being mounted above and connected sealingly to said shrunk-on ring to form said annular channel, said mandrel having at least one helical groove, with a depth that decreases in a direction of said die slit and begins in said initial region for receiving said melt from said at least one borehole, and said shrunk-on ring enclosing sealingly said initial region including a groove-free portion of said mandrel and said beginning of said at least one helical groove.
Dependencies are inferred from the claim text.