Cellulosic Composites Comprising Wood Pulp
The present invention discloses cellulosic composites that include mechanical or chemical pulp, and methods for producing such cellulosic composites. Embodiments of such composites may exhibit improved mechanical properties and moisture resistance when compared to composites derived from conventional cellulosic feedstock.
1 . A cellulosic composite comprising wood pulp obtained by melt processing wet wood pulp having greater than 10 wt % moisture and polymeric matrix, wherein the pulp is substantially uniformly dispersed within the polymeric matrix.
2 . The cellulosic composite of claim 1 , wherein said melt processing forms a masterbatch.
3 . The cellulosic composite of claim 1 , wherein said wet wood pulp has moisture content of at least 20 wt %.
4 . The cellulosic composite of claim 3 , wherein said wet wood pulp has moisture content of at least 25 wt %.
5 . The cellulosic composite of claim 1 , wherein the wood pulp is one of mechanical pulp and chemical pulp.
6 . The cellulosic composite of claim 5 , wherein the wood pulp is said chemical pulp.
7 . The cellulosic composite of claim 6 , wherein said chemical pulp is kraft pulp obtained via a kraft process.
8 . The cellulosic composite of claim 5 , wherein the pulp is said mechanical pulp.
9 . The cellulosic composite of claim 8 , wherein the mechanical pulp comprises lignin, the lignin making up 5% to 35% of the dry weight of the pulp.
10 . The cellulosic composite of claim 1 , wherein the proportion of the pulp is in the range of more than 50% and up to 99% by weight of the composite.
11 . The cellulosic composite of claim 10 , wherein the proportion of the pulp is in the range of more than 50% and up to 95% by weight of the composite.
12 . The cellulosic composite of claim 11 , wherein the proportion of the pulp is in the range of more than 50% and up to 90% by weight of the composite.
13 . The cellulosic composite of claim 10 , wherein the proportion of the pulp is in the range of 80% to 99% by weight of the composite.
14 . The cellulosic composite of claim 1 , wherein the polymeric matrix comprises at least one of: high density polyethylene, low density polyethylene, linear low density polyethylene, functional polyolefin copolymers including polyolefin based ionomers, polypropylene, polyolefin copolymers, polystyrene, polystyrene copolymers, polyacrylates, polymethacrylates, polyesters, polyvinylchloride (PVC), fluoropolymers, polyamides, polyether imides, polyphenylene sulfides, polysulfones, polylactic acid (PLA), polyacetals, polycarbonates, polyphenylene oxides, polyurethanes, and thermoplastic elastomers.
15 . The cellulosic composite of claim 1 , wherein the polymeric matrix comprises bioplastics polymers comprising at least one of: biobased polyesters, biodegradable polyesters, compostable polyesters, polyamides, polyurethanes, polyacrylates, polyolefins, thermoplastic starches, cellulosics, PLA (Polylactic acid), PHA (Polyhydroxyalkanoates), PBAT (polybutyrate adipate terephthalate), PBS (polybutylene succinate), PCL (polycaprolactones), and PGA (Polygycolic acid).
16 . The cellulosic composite of claim 14 , wherein the polyolefin copolymers comprise one of: ethylene-butene, ethylene-octene and ethylene vinyl alcohol; and wherein said polystyrene copolymers comprise one of: high impact polystyrene, and acrylonitrile butadiene styrene copolymer.
17 . The cellulosic composite of claim 1 , comprising an additive.
18 . The cellulosic composite of claim 17 , wherein the additive is at least one of: antioxidant, light stabilizer, fiber, blowing agent, foaming additive, antiblocking agent, heat stabilizer, impact modifier, biocide, antimicrobial additive, compatibilizer, plasticizer, tackifier, processing aid, lubricant, coupling agent, flame retardant, pigment and colorant.
19 . The cellulosic composite of claim 17 , wherein the additive is a coupling agent.
20 . The cellulosic composite of claim 19 , wherein the coupling agent is at least one of: silane, zirconate, titanate, functionalized polymer and maleic anhydride grafted polymer.
21 . The cellulosic composite of claim 19 , wherein the coupling agent is in the range of 0.1% to 10% by weight of the composite.
22 . The cellulosic composite of claim 1 , further comprising additional filler.
23 . The cellulosic composite of claim 22 , wherein said additional filler comprises at least one of: talc, mica, clay, silica, alumina, carbon fiber, carbon black, glass fiber, wood flour, wood fibers, non-wood plant fibers, sawdust, wood shavings, newsprint, paper, flax, hemp, wheat straw, rice hulls, kenaf, jute, sisal, peanut shells, soy hulls, lignin, calcium carbonate and cellulosic fiber.
24 . The cellulosic composite of claim 22 , wherein the additional filler is in the range of 1% to 90% by weight of the composite.
25 . The cellulosic composite of claim 24 , wherein the additional filler is in the range of 5% to 75% by weight of the composite.
26 . The cellulosic composite according to claim 1 , wherein the composite has a moisture uptake of less than 1 wt % after 96 hours of immersion in water.
27 . A cellulosic composite according to claim 26 , wherein the polymeric composite forms at least a portion of an article selected from the group consisting of: an automotive component, decking, fencing, railing, roofing, siding, a consumer article, an appliance component and a 3D printed component.
28 . A process for making a cellulosic composite, the process comprising: a first step of melt processing a mixture comprising wet pulp having greater than 10 wt % moisture and a polymeric matrix.
29 . The process of claim 28 , wherein the moisture content said pulp is at least 15% by weight of the pulp.
30 . The process of claim 29 , wherein the moisture content said pulp is at least 20% by weight of the pulp.
31 . The process of claim 30 , wherein the moisture content said pulp is at least 30% by weight of the pulp.
32 . The process of claim 28 , further comprising a second step of melt processing a masterbatch formed from said first step, to form the composite.
33 . The process of claim 32 , further comprising diluting the masterbatch prior to said second step of melt processing.
34 . The process of claim 32 , wherein the mixture further comprises at least one of: an additive and a filler.
35 . The process of claim 32 , wherein each of the first and second steps of melt processing is one of: compounding, injection molding and extrusion.
36 . The process of claim 32 , wherein after the first step of melt processing the masterbatch contains pulp the range of 50% to 99% by weight and, after the second step of melt processing the composite contains pulp the range of 5% to 50% by weight.
37 . The process of claim 32 , wherein the polymeric matrix is a thermoplastic polymeric matrix.
38 . The process of claim 32 , further comprising increasing the moisture content of the pulp prior to the first step of melt processing.
39 . A cellulosic composite produced according to the process of claim 28 .
40 . A process for making an article of manufacture comprising:
a) melt processing a mixture comprising wet pulp having greater than 10 wt % moisture and a polymeric matrix; and
b) extruding, compression molding or injection molding, the melt processed mixture into the article.
41 . The process of claim 40 , further comprising pelletizing the melt processed mixture prior to said extruding.
42 . The cellulosic composite of claim 1 , wherein the wood pulp is recycled fiber.
43 . The process of claim 28 , wherein said melt processing comprises at least one of: extrusion, injection molding, blow molding, rotomolding, thermokinetic mixing and batch mixing.
44 . The process of claim 43 , wherein said thermokinetic mixing comprises pellet milling.
45 . The process of claim 40 , wherein said melt processing comprises at least one of: extrusion, injection molding, blow molding, rotomolding, thermokinetic mixing and batch mixing.
46 . The process of claim 45 , wherein said thermokinetic mixing comprises pellet milling.