| 摘要 |
A polymer extrusion assembly for forming a striped extrusion. The assembly includes conventional components for conveying a primary and a secondary molten polymer of differing colors, arranged concentrically, toward a die sub-assembly, which may be rotatable. The die has an opening for conveying the primary polymer to form an extruded tube. The periphery of the die opening is modified to cause thinning or breaching of the secondary polymer skin layer as it passes through the die. The periphery may be provided with teeth which furrow the skin layer, exposing the primary polymer underneath, or the periphery may be comprise a plurality of facets meeting at sharp internal corners, wherein the skin layer is forced into the corners and is breached at the centers of the facets, again exposing the primary polymer underneath in longitudinal stripes. By causing the die sub-assembly to rotate during extrusion, a spirally striped extrusion is formed.
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