Variegated composites and related methods of manufacture
Embodiments of the invention include a composite. The composite includes a crystalline polymer, a plurality of wood fibers blended with the crystalline polymer, an outer surface, and an amorphous polymer visible on the outer surface. The amorphous polymer has a first color and the blend of the crystalline polymer and the plurality of wood fibers has a second color different from the first color. The invention also includes a method of manufacturing the wood-plastic composites such that one polymer is shifted in the composite relative to the other polymer.
1 . A composite, comprising:
a first polymer;
a plurality of wood fibers dispersed in the first polymer;
an outer surface; and
a second polymer adapted to not blend substantially with the first polymer;
wherein the first polymer and the second polymer form a pattern on the outer surface of the composite.
2 . The composite of claim 1 , wherein the first polymer is at least one of polypropylene and polyethylene.
3 . The composite of claim 1 , wherein the second polymer is at least one of a polymethylmethacrylate, an alphamethylstyrene acrylonitrile, and a polycarbonate.
4 . The composite of claim 1 , wherein the outer surface includes streaks of the second polymer.
5 . The composite of claim 1 , wherein the first polymer has a melting temperature that is substantially the same as a melting temperature of the second polymer.
6 . The composite of claim 1 , wherein the outer surface is variegated.
7 . The composite of claim 1 , wherein a first portion of the outer surface has a first color and a second portion of the outer surface has a second color.
8 . The composite of claim 1 , further comprising a third polymer configured to resist blending with the first polymer;
wherein the composite is manufactured such that the third polymer is deliberately visible on the outer surface,
wherein the third polymer has a third color different from the first polymer and the second polymer.
9 . The composite of claim 1 , wherein the composite is at least one of a building material, a decking material, a railing component, and a decking board.
10 . The composite of claim 1 , further comprising a colorant blended with one of the first polymer and the second polymer.
11 . A method of manufacturing a wood-plastic composite, comprising:
providing a first polymer;
providing a plurality of wood fibers;
providing a second polymer not substantially soluble in the first polymer;
melting the first polymer;
blending the first polymer and the plurality of wood fibers to form a blend;
adding the second polymer in an unmelted state to the blend to form a feed; and
forming a profile body from the feed, the profile body further comprising a pattern formed by the first polymer and the second polymer.
12 . The method of claim 11 , further comprising forming streaks of the second polymer on the outer surface.
13 . The method of claim 11 , further comprising forming streaks of the first polymer on the outer surface.
14 . The method of claim 11 , further comprising shifting the second polymer towards the outer surface.
15 . The method of claim 11 , further comprising variegating the outer surface.
16 . The method of claim 11 , further comprising providing at least one of a single screw extruder and a double screw extruder,
wherein the step of extruding includes extruding the feed via the at least one of the single-screw extruder and the double screw extruder.
17 . The method of claim 11 , wherein the step of mixing includes forming a first color from the second polymer and forming the second color from a blend of the first polymer and the plurality of wood fibers.
18 . The method of claim 11 , further comprising providing a third polymer not substantially soluble in the first polymer;
adding the third polymer in an unmelted state to the blend to form the feed,
wherein the step of extruding includes forming the profile body such that the outer surface deliberately evinces a third color different from the first polymer and the second polymer.
19 . The method of claim 11 , further comprising providing a core,
wherein the step of forming the profile body includes forming the profile body around at least a portion of the core.
20 . The method of claim 11 , further comprising providing a colorant; and
blending the colorant with one of the first polymer and the second polymer.
21 . The composite of claim 1 , wherein the first polymer has a first color and the second polymer has a second color.
22 . The composite of claim 1 , wherein the second polymer is not substantially soluble in the first polymer.
23 . The method of claim 11 , wherein the first polymer has a first color and the second polymer has a second color.
24 . The method of claim 11 , wherein the second polymer is not substantially soluble in the first polymer.