Dry-forming three dimensional wood fiber webs

1. A method for the dry-formation of a uniformly strong deep drawn, three-dimensional single-ply wood fiber structural core for use in making a panel having thin-board face panels, which comprises:

providing a preformed, substantially flat, dry-formed single-ply mat of wood fibers having a moisture content in a range of 8 weight % to 16 weight %;

precompressing said pre-formed single-ply mat of wood fibers;

providing a three-dimensional mold which comprises laminating platforms, load-bearing diagonal elements, anticline protrusions having ridges, fillets and curved corners to facilitate fiber draw during the molding process at the intersection of the laminating platforms and load-bearing diagonal elements, the longitudinal dimensions of adjoining ridges being alternatively shorter and longer to eliminate any uninterrupted straight and clear line of sight along a transverse row of adjoining ridges or valleys formed by the intersection of syncline indentations and anticline protrusions with the horizontal plane of the ridges;

introducing the precompressed dry-formed single-ply mat of wood fibers into the three-dimensional mold; and

drawing and molding the precompressed dry-formed single-ply mat of wood fibers into said uniformly strong three-dimensional single-ply wood fiber structural core in a substantially single pressing motion, wherein the single-ply core has a depth in the vertical axis of about ½″ up to about 1½″, wherein the panel produced by attaching thin-board face panels to the outer surfaces of said single-ply core have a Flat Crush strength which is at least about two times greater than a Flat Crush strength of wet-formed panels at equivalent weights and thicknesses.

2. The method of claim 1 , wherein the duration of the pressing contact time is not more than about 120 seconds.

3. The method of claim 1 , wherein the duration of drawing and molding of the single-ply mat of wood fibers into said three-dimensional single-ply wood fiber structural core is at least about two times less than that of the wet-formation pressing cycle for drawing and molding the mat of wood fibers into said three-dimensional wood fiber structural core.

4. The method of claim 1 , wherein a thin-board face panel is applied to the dry-formed three-dimensional single-ply wood fiber structural core, without substantial telegraphing through the thin-board face panel.

5. The method of claim 1 , wherein drawing and molding the mat of wood fibers into said three-dimensional single-ply wood fiber structural core is pressed at temperatures of from about 260° F., up to about 410° F.

6. The method of claim 4 , wherein front-side to back-side imbalance of the thin-board face panel is substantially minimized.

7. The method of claim 1 , wherein the three-dimensional single-ply wood fiber structural core comprises diagonal load-bearing elements, and the angles for said diagonal load-bearing elements are from about 35 degrees up to about 70 degrees.

8. The method of claim 1 , wherein drawing and molding the single-ply mat of wood fibers into said three-dimensional single-ply wood fiber structural core is pressed at pressures of from about 500 p.s.i., up to about 1,400 p.s.i.

9. The method of claim 8 , wherein a thin-board face panel is applied to the dry-formed three-dimensional single-ply wood fiber structural core and the laminating platform dimension, as a percentage of the contact area of the horizontal plane of the thin-board face panel, is from about 10% up to 30%.

10. The method of claim 1 , wherein the wall thickness of the three-dimensional single-ply wood fiber structural core is from about 0.080″ up to about 0.180″.

11. The method of claim 8 , wherein the density of the three-dimensional single-ply wood fiber structural core is from about 45 pounds per cubic foot up to about 70 pounds per cubic foot.

12. A method for the dry-formation of a composite panel including a uniformly strong deep drawn, three-dimensional single-ply wood fiber structural core, having a thin-board face panels attached to the outer surfaces thereof, which comprises:

forming a preformed, substantially flat, dry-formed single-ply mat of wood fibers having a moisture content in a range of 8 weight % to 16 weight %;

precompressing said pre-formed single-ply mat of wood fibers;

providing a three-dimensional mold which comprises laminating platforms, load-bearing diagonal elements, anticline protrusions having ridges, fillets and curved corners to facilitate fiber draw during the molding process at the intersection of the laminating platforms and load-bearing diagonal elements, the longitudinal dimensions of adjoining ridges being alternatively shorter and longer to eliminate any uninterrupted straight and clear line of sight along a transverse row of adjoining ridges or valleys formed by the intersection of syncline indentations and anticline protrusions with the horizontal plane of the ridges;

introducing the precompressed dry-formed single-ply mat of wood fibers into the three-dimensional mold;

drawing and molding the precompressed dry-formed single-ply mat of wood fibers into said uniformly strong three-dimensional single-ply wood fiber structural core in a substantially single pressing motion, wherein the single-ply core has a depth in the vertical axis of about ½″ up to about 1½″; and

attaching said thin-board face panels to said outer surfaces of said uniformly strong deep drawn, three-dimensional single-ply wood fiber structure core to form said composite panel, said composite panel having a Flat Crush strength which is at least about two times greater than a Flat Crush strength of wet-formed panels at equivalent weights and thicknesses.

13. The method of claim 12 , wherein the duration of the drawing and molding step is not more than about 120 seconds.

14. The method of claim 12 , wherein the duration of drawing and molding of the single-ply mat the single-ply mat of wood fibers into said three-dimensional single-ply wood fiber structural core is at least about two times less than that of the wet-formation pressing cycle for drawing and molding the mat of wood fibers into said three-dimensional wood fiber structural core.

15. The method of claim 12 , wherein drawing and molding the single-ply mat of wood fibers into said three-dimensional single-ply wood fiber structural core is pressed at temperatures of from about 260° F., up to about 410° F.

16. The method of claim 12 , wherein drawing and molding the single-ply mat of wood fibers into said three-dimensional single-ply wood fiber structural core is pressed at pressures of from about 500 p.s.i, up to about 1,400 p.s.i.

17. The method of claim 1 , wherein panels produced by attaching thin-board face panels to the outer surfaces of said single-ply core have a Flat Crush strength which is at least about three times greater than a Flat Crush strength for wet-formed panels at equivalent weights and thicknesses.

18. The method of claim 1 , wherein panels produced by attaching thin-board face panels to the outer surfaces of said single-ply core have a Flat Crush strength which is at least about four times greater than a Flat Crush strength for wet-formed panels at equivalent weights and thicknesses.

19. The method of claim 1 , wherein panels produced by attaching thin-board face panels to the outer surfaces of said single-ply core have a Flat Crush strength which is at least about five times greater than a Flat Crush strength for wet-formed panels at equivalent weights and thicknesses.

20. The method of claim 1 wherein the precompressed dry-formed single-ply mat of wood fibers includes methylene diisocyanate resin.

21. The method of claim 12 wherein the precompressed dry-formed single-ply mat of wood fibers includes methylene diisocyanate resin.