Layered composites
View Patent ↗Useful composites and methods of using such composites are provided. The composites include an outer layer containing a first polymeric material, an intermediate layer circumscribed by the outer layer and containing a second polymeric material, and an inner layer circumscribed by the intermediate layer and containing a third polymeric material. The inner layer, in combination with the intermediate layer, is structured and effective to reinforce the composite relative to a substantially identical composite without the inner layer. The present composites can be produced using co-extrusion processing.
1. A method for producing a composite comprising a construction element having a length, a substantially non-hollow cross section perpendicular to the length, an outer weatherable layer, an intermediate layer and an inner layer, the method comprising the steps of:
providing, in extrudable form, (1) a first composition comprising a first weatherable polymeric material, (2) a second composition comprising a second polymeric material, and (3) a third composition comprising a third polymeric material,
introducing each of the compositions into a different extrusion pathway of a single extruder/feedblock/pipehead assembly adapted to be fed by three co-extruders, wherein the extrusion pathways of the first, second and third polymeric materials are arranged such that, in cross section, the third polymeric material is circumscribed by the second polymeric material, and the second polymeric material is circumscribed by the first polymeric material;
extruding the compositions to produce an annular form, wherein the extruder/feedblock/pipehead assembly is arranged to produce said annular form through a convergent flow pathway;
introducing the annular form into a forming/shaper die having a desired cross sectional shape; to produce a reshaped form wherein the annular form is collapsed about a central hollow to form a substantially non-hollow, layered form, and
cutting the reshaped form into a desired length,
wherein the composite thus formed comprises a rigid construction element having said length, a substantially non-hollow cross-section perpendicular to the length, an outer weatherable layer, an intermediate layer and an inner layer.
2. The method of claim 1 further comprising causing the formation of an intermediate foam containing the second polymeric material, and an inner foam containing the third polymeric material.
3. The method of claim 1 wherein the first and second polymeric materials are different.
4. The method of claim 1 wherein the second and third polymeric materials are different.
5. The method of claim 1 wherein the first and third polymeric materials are different.
6. The method of claim 1 wherein each of the first, second and third polymeric materials is different.
7. The method of claim 1 wherein the composite is extruded in the shape of a board.
8. The method of claim 1 wherein the composite is extruded in the shape of a slat.
9. The method of claim 8 wherein the composite is extruded in the shape of a window covering slat.
10. The method of claim 8 wherein the composite is extruded in the shape of a siding component.
11. The method of claim 1 wherein the composite is extruded in the shape of a paneling component.
12. The method of claim 1 wherein the composite is extruded in the shape of a fence component.
13. The method of claim 1 wherein the composite is structured to be useful as a component selected from the group consisting of a window blind component, a siding component, a molding component, a paneling component, a fencing component, and a decking component.