US 7,247,012 B2Granted

Rotatable head for forming spiral extrusions

AssigneeCangen Holdings, Inc.

InventorsPrem Anand, John C. Giardina

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Abstract

A polymer extrusion crosshead assembly for forming a spirally-striped extrusion. The assembly includes conventional components for admitting, turning, and accelerating primary molten polymer toward a novel rotating die sub-assembly. A body element includes an axial counterbore for receiving a manifold supply block in communication with a source of secondary striping polymer. A wear plate is attached to the manifold block. The die sub-assembly includes a striping die having an annular passage for conveying the primary polymer to form an extruded tube or a core material coating. The die is loaded against the wear plate by a Belleville washer. The die includes one or more striping nozzles in communication with the manifold block for injecting secondary striping polymer into the annular stream of primary polymer flowing through the die, creating a longitudinal stripe of striping polymer. Rotating the die while extruding both polymers yields a helically striped (spiral) extrusion.

Claims14

Dependent claims

An extrusion head assembly for continuous extrusion of a primary molten polymer in a predetermined shape and a secondary molten polymer in a stripe inserted into said predetermined shape, the primary and secondary molten polymers being supplied from first and second sources, comprising:

a) a fixed member for conveying said primary molten polymer in an annular stream axially of an axis of said head assembly, said fixed member including a body element;
b) a manifold block disposed against said body element, said manifold block including a distribution channel for receiving and distributing said secondary polymer;
c) a wear plate disposed against said manifold block;
and
d) a die sub-assembly rotatably disposed on said body element for receiving said annular stream of primary molten polymer from said fixed member and extruding said predetermined shape, said die sub-assembly including an extrusion die in contact with said wear plate and having an opening for extruding said predetermined shape and having means for communicating with said distribution channel to receive said secondary polymer therefrom to form said inserted stripe, said sub-assembly further including means for rotating said die about said axis,
wherein said sub-assembly includes spring means for axially loading said extrusion die against said wear plate.

3 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/849,340Filed 19 May 2004
Published: US 2005/0260408 A124 Nov 2005
Granted: 24 Jul 2007
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

B29C 48/33
With annular openings, e.g. for forming tubular articles: with parts rotatable relative to each other
B29C 48/06
Characterised by the shape of the extruded material at extrusion: rod-shaped
B29C 48/07
Characterised by the shape of the extruded material at extrusion: flat, e.g. panels
B29C 48/09
Characterised by the shape of the extruded material at extrusion: articles with cross-sections having partially or fully enclosed cavities, e.g.…