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US 6,958,128 B2Granted
Dynamic mixer screw tip
AssigneeCertainTeed Corporation
InventorsThomas A. Gates, James N. Valentine, David H. Steele, Steven H. Bowens
Life of this patent
Estimating the term…
Abstract
The present invention includes a screw tip for an extruder screw for effecting mixing in an extruder. The screw tip has a substantially conical outside surface and at least one discontinuous fin. The at least one fin protrudes from the outside surface of the screw tip.
Claims21
A screw tip for an extruder screw for effecting mixing in an extruder comprising:
- a substantially conical outside surface, and
- a plurality of discontinuous fins protruding from the outside surface of the screw tip,
- wherein a first pair of opposing fins include a first number of fin slots which divide each fin of the first pair of fins into a first number of fin components, and wherein a second pair of opposing fins include a second number of one or more fin slots which divides each fin of the second pair of fins into a second number of fin components different from the first number of fin components.
An extruder for extrusion of thermoplastic materials comprising:
- a hollow barrel defining a feed channel;
- at least one extruder screw rotatably mounted in the feed channel;
- and
- at least one screw tip coaxially mounted on a respective extruder screw and having a plurality of discontinuous fins extending from a substantially conical outside surfaces,
- wherein a first pair of opposing fins include a first number of fin slots which divide each fin of the first pair of fins into a first number of fin components, and wherein a second pair of opposing fins include a second number of one or more fin slots which divides each fin of the second pair of fins into a second number of fin components different from the first number of fin components.
2 more elements
An extrusion process of the type by which a polymeric material is fed by a screw mixer through a feed channel to a die, the improvement comprising:
- mixing a molten material with a rotating screw tip having a plurality of fins protruding from a substantially conical outside surface of the screw tip, at least four of said fins being discontinuous, wherein a first pair of opposing fins include a first number of fin slots which divide each fin of the first pair of fins into a first number of fin components, and wherein a second pair of opposing fins include a second number of one or more fin slots which divides each fin of the second pair of fins into a second number of fin components different from the first number of fin components.
Dependencies are inferred from the claim text.