Extruded synthetic wood composition and method for making same

Claim 2

A process for the production of a composite material from particles of cellulosic material comprising the steps of: a. combining the cellulosic material with a sufficient amount of thermoplastic material to form a combined product; b. extruding the combined product under sufficient conditions to blend the combined product together into a homogeneous mixture; c. passing the homogeneous mixture through a transition die to pre-shape the homogeneous mixture into a shape approximating that of a finished product and to expand the homogeneous mixture; d. passing the homogeneous mixture through a stranding die to form a plurality of adjacently positioned strands of homogeneous mixture; and e. passing the plurality of strands through a molding die for a time sufficient to compress the strands together and bond the strands to each other.

Claim 3

The process of claim 1 further comprising the step of passing the homogeneous mixture through an adapter die to control a volume of the homogeneous mixture allowed into the transition die.

Claim 4

The process of claim 1, wherein the cellulosic material is selected from the group consisting of newspapers, alfalfa, wheat pulp, wood flour, wood flakes, wood fiber, ground wood, wood veneers, wood laminates, paper, cardboard, straw, and mixtures thereof.

Claim 5

The process of claim 1 wherein the cellulosic material is shredded or fibered.

Claim 6

The process of claim 1 further comprising drying the cellulosic material prior to step a. to a moisture content between about 1% and 9%.

Claim 7

The process of claim 1 further comprising drying the cellulosic material prior to step a. to a moisture content of 2%.

Claim 8

The process of claim 1 wherein the thermoplastic material is selected from the group consisting of multi-layer films, poly-vinyl chloride, polyolefins, copoly-ethylene-vinyl acetate and waste plastic sawdust.

Claim 9

The process of claim 1 wherein the ratio of cellulosic material to thermoplastic material is between approximately 1:1 and 1:0.

Claim 10

The process of claim 1 wherein the combined product is extruded at a temperature as low as about 100° F.

Claim 11

The process of claim 1 wherein the combined product is extruded at a temperature between about 100° F. and 400° F.

Claim 12

The process of claim 1 wherein the combined products is extruded at a temperature between about 150° F. and 200° F.

Claim 13

The process of claim 1 wherein the combined product is extruded at a temperature of about 180° F.

Claim 14

The process of claim 12 wherein the flow rate of the extruder is between approximately 100 and 2500 pounds per hour.

Claim 15

The process of claim 12 wherein the flow rate of the extruder is approximately 600 pounds per hour.

Claim 16

The process of claim 1 further comprising combining the cellulosic material with the thermoplastic material in the presence of a cross-linking agent.

Claim 17

The process of claim 15 wherein the cross-linking agent is selected from the group consisting of polyurethanes, phenolic resins, unsaturated polyesters and epoxy resins.

Claim 18

The process of claim 1 further comprising combining the cellulosic material with the thermoplastic material in the presence of a lubricant.

Claim 19

The process of claim 17 wherein the lubricant is selected from the group consisting of zinc stearate and paraffin-type wax.

Claim 20

The process of claim 1 further comprising combining the cellulosic material with the thermoplastic material in the presence of one or more of the following: accelerators, inhibitors, enhancers, compatibilizers and blowing agents.

Claim 21

The process of claim 1 wherein each of the plurality of adjacent positioned strands has a surface temperature hotter than an interior temperature of each strand.

Claim 22

The process of claim 1 wherein the stranding die is a multi-aperture die comprising means to increase the temperature of the outer surface of each of the strands that are formed in the die.

Claim 23

The process of claim 21 wherein the stranding die comprises multiple apertures arranged in a manner to facilitate proper volume distribution for the strands, wherein all of the apertures are substantially round.

Claim 24

The process of claim 22 wherein the multiple apertures each comprise a diameter of approximately one-eighth of an inch.

Claim 25

The process of claim 1 wherein the stranding die is a gas-evacuation stranding die comprising means to facilitate the removal of unwanted process gases which are present when using volatile cross-linking agents.

Claim 26

The process of claim 1 comprising after passing the homogenous strands through the molding die, passing the strands through a settling die for a time sufficient to bond the individual strands together to a molded extrudate.

Claim 27

The process of claim 25 comprising spraying the molded extrudate with a cooling fluid sufficient to impart a hardened glaze on the molded extrudate.

Claim 28

The process of claim 26 wherein the fluid is water.

Claim 29

The process of claim 26 comprising spraying the molded extrudate prior to exposing the extrudate to air.

Claim 30

The process of claim 1 further comprising cooling the formed product.

Claim 31

The process of claim 29 comprising cooling the formed product under negative pressure.

Claim 32

A process for the production of a composite material from particles of cellulosic material comprising the steps of: a. drying the cellulosic material to a moisture content between about 1% and 9%; b. combining the cellulosic material with a sufficient amount of thermoplastic material in the presence of a cross-linking agent and a lubricant to form a combined product, wherein the ratio of cellulosic material to thermoplastic material is between approximately 1:1 and 1:0; c. extruding the combined product under sufficient conditions to blend the combined product together into a homogeneous mixture, wherein the combined product is extruded at a temperature between about 100° F. and 400° F., and wherein the flow rate of the extruder is between approximately 100 and 2500 pounds per hour; d. passing the homogenous mixture through a transition die to preshape the homogeneous mixture into a shape approximating that of a finished product and to expand the homogeneous mixture; e. passing the homogeneous mixture through a stranding die to form a plurality of adjacently positioned strands of homogeneous mixture, wherein each of the plurality of adjacent positioned strands has a surface temperature hotter than an interior temperature of each strand; f. passing the plurality of strands through a molding die for a time sufficient to compress the strands together and bond the strands to each other; g. passing the strands through a settling die for a time sufficient to bond the individual strands together to a molded extrudate; h. spraying the molded extrudate with a cooling fluid sufficient to impart a hardened glaze on the molded extrudate; and i. cooling the formed product.

Claim 33

A process for the production of a composite material from particles of cellulosic material comprising the steps of: a. drying the cellulosic material to a moisture content between about 1% and 9%; b. combining the cellulosic material with a sufficient amount of thermoplastic material in the presence of a cross-linking agent and a lubricant to form a combined product, wherein the ratio of cellulosic material to thermoplastic material is between approximately 1:1 and 1:0; c. extruding the combined product under sufficient conditions to blend the combined product together into a homogeneous mixture, wherein the combined product is extruded at a temperature between about 100° F. and 400° F., and wherein the flow rate of the extruder is between approximately 100 and 2500 pounds per hour; d. passing the homogenous mixture through a transition die to preshape the homogeneous mixture into a shape approximating that of a finished product and to expand the homogeneous mixture; e. passing the homogeneous mixture through a stranding die to form a plurality of adjacently positioned strands of homogeneous mixture, wherein each of the plurality of adjacent positioned strands has a surface temperature hotter than an interior temperature of each strand; f. passing the plurality of strands through a molding die for a time sufficient to compress the strands together and bond the strands to each other; g. passing the strands through a settling die for a time sufficient to bond the individual strands together to a molded extrudate; h. spraying the molded extrudate with a cooling fluid sufficient to impart a hardened glaze on the molded extrudate; and i. cooling the formed product.

Claim 34

The process of claim 31 wherein the cellulosic material is selected from the group consisting of newspapers, alfalfa, wheat pulp, wood flour, wood flakes, wood fibers, ground wood, wood veneers, wood laminates, paper, cardboard, straw, and other cellulosic fibrous materials.

Claim 35

The process of claim 31 wherein the cellulosic material is shredded or fibered.

Claim 36

The process of claim 31 wherein the thermoplastic material is selected from the group consisting of multi-layer films, poly-vinyl chloride, polyolefins, copoly-ethylene-vinyl acetate and waste plastic sawdust.

Claim 37

The process of claim 31 wherein the combined products is extruded at a temperature between about 150° F. and 200° F.

Claim 38

A low-temperature extruder system for forming a composite molded extrudate from a mixture of organic fibrous material and thermoplastic material, comprising: a. a hopper to receive and form a mixture of the organic fibrous material and the thermoplastic material; b. an extruder to extrude the mixture; c. a first transition die comprising an aperture to receive the mixture and form it to an initial shape and to extrude the formed mixture; d. a second stranding die, connected to the first transition die, provided with a plurality of stranding apertures to receive and shear the formed mixture into a plurality of individual strands each having an exterior surface; e. a third molding die, connected to the second stranding die, provided with an aperture to receive and compress the individual strands into a final molded shape; and f. a fourth shaping die, connected to the third molding die, provided with an extrudate shape-forming aperture for molding the molded extrudate.

Claim 39

A low-temperature extruder system for forming a composite molded extrudate from a mixture of organic fibrous material and thermoplastic material, comprising: a. a hopper to receive and form a mixture of the organic fibrous material and the thermoplastic material; b. an extruder to extrude the mixture; c. a first transition die comprising an aperture to receive the mixture and form it to an initial shape and to extrude the formed mixture; d. a second stranding die, connected to the first transition die, provided with a plurality of stranding apertures to receive and shear the formed mixture into a plurality of individual strands each having an exterior surface; e. a third molding die, connected to the second stranding die, provided with an aperture to receive and compress the individual strands into a final molded shape; and f. a fourth shaping die, connected to the third molding die, provided with an extrudate shape-forming aperture for molding the molded extrudate.

Claim 40

The low temperature extruder system of claim 36 further comprising an adapter die located between the extruder and the first transition die, the adapter die being provided with an aperture to control the amount of mixture entering the first transition die.

Claim 41

The low temperature extruder system of claim 36 wherein the first transition die comprises a first front face having a generally round orifice and a second rear face having an orifice similar to a shape of a finished product.

Claim 42

The low temperature extruder system of claim 36 wherein the third molding die comprises a first front face equivalent in shape to the second rear face of the first transition die and a second rear shape-forming face to form the shape of the molded extrudate.

Claim 43

The low temperature extruder system of claim 36 wherein the second stranding die comprises a first surface and a second surface, comprising: a. a plurality of gas evacuation channels located on the first surface of the second die to receive and evacuate gases discharged from shearing the formed mixture; and b. a plurality of gas evacuation vents, having inlets located on the first surface connected to the gas channels and outlets located on the second surface, for receiving and evacuating gases from the gas evacuation channels.

Claim 44

The low temperature extruder system of claim 40 wherein the gas evacuation vent outlets have a larger circumference than the inlets, providing a venturi effect to increase gas evacuation efficiency.

Claim 45

The low temperature extruder system of claim 40 wherein the gas evacuation channels are connected to the stranding apertures in a grid formation.

Claim 46

The low temperature extruder system of claim 40 wherein the gas evacuation vents are located substantially at a midpoint between the stranding apertures.

Claim 47

The low temperature extrude system of claim 36 further comprising a spray head system for receiving the molded extrudate passing from fourth shaping die.

Claim 48

A low-temperature extruder system for forming a composite molded extrudate from a mixture of organic fibrous material and thermoplastic material, comprising: a. a hopper to receive and form a mixture of the organic fibrous material and the thermoplastic material; b. an extruder to extrude the mixture; c. an adapter die connected to the extruder, the adapter die being provided with an aperture to control the quantity of mixture flowing from the extruder; d. a first transition die comprising an aperture to receive the mixture and form it to an initial shape and to extrude the formed mixture, wherein the first transition die comprises a first front face having a generally round orifice and a second rear face having an orifice similar to a shape of a finished product; e. a second stranding die, connected to the first transition die, provided with a plurality of stranding apertures to receive and shear the formed mixture into a plurality of individual strands each having an exterior surface, wherein the second stranding die comprises a first surface and a second surface, comprising: i. a plurality of gas evacuation channels located on the first surface of the second die to receive and evacuate gases discharged from shearing the formed mixture; and ii. a plurality of gas evacuation vents, having inlets located on the first surface connected to the gas channels and outlets located on the second surface, for receiving and evacuating gases from the gas evacuation channels, wherein the gas evacuation vent outlets have a larger circumference than the inlets, providing a venturi effect to increase gas evacuation efficiency; f. a third molding die, connected to the second stranding die, provided with an aperture to receive and compress the individual strands into a final molded shape, wherein the third molding die comprises a first front face equivalent in shape to the second rear face of the first transition die and a second rear shape-forming face to form the shape of the molded extrudate; g. a fourth shaping die, connected to the third molding die, provided with an extrudate shape-forming aperture for molding the molded extrudate; and h. a spray head system for receiving the molded extrudate passing from fourth shaping die.

Claim 49

A low-temperature extruder system for forming a composite molded extrudate from a mixture of organic fibrous material and thermoplastic material, comprising: a. a hopper to receive and form a mixture of the organic fibrous material and the thermoplastic material; b. an extruder to extrude the mixture; c. an adapter die connected to the extruder, the adapter die being provided with an aperture to control the quantity of mixture flowing from the extruder; d. a first transition die comprising an aperture to receive the mixture and form it to an initial shape and to extrude the formed mixture, wherein the first transition die comprises a first front face having a generally round orifice and a second rear face having an orifice similar to a shape of a finished product; e. a second stranding die, connected to the first transition die, provided with a plurality of stranding apertures to receive and shear the formed mixture into a plurality of individual strands each having an exterior surface, wherein the second stranding die comprises a first surface and a second surface, comprising: i. a plurality of gas evacuation channels located on the first surface of the second die to receive and evacuate gases discharged from shearing the formed mixture; and ii. a plurality of gas evacuation vents, having inlets located on the first surface connected to the gas channels and outlets located on the second surface, for receiving and evacuating gases from the gas evacuation channels, wherein the gas evacuation vent outlets have a larger circumference than the inlets, providing a venturi effect to increase gas evacuation efficiency; f. a third molding die, connected to the second stranding die, provided with an aperture to receive and compress the individual strands into a final molded shape, wherein the third molding die comprises a first front face equivalent in shape to the second rear face of the first transition die and a second rear shape-forming face to form the shape of the molded extrudate; g. a fourth shaping die, connected to the third molding die, provided with an extrudate shape-forming aperture for molding the molded extrudate; and h. a spray head system for receiving the molded extrudate passing from fourth shaping die.