Composite panel with fixed void content and methods of making same

1. A method for making a porous composite panel having a desired void content comprising:

laying on a surface a first ply of resin;

placing on the first ply a filament;

laying on the first ply and the filament a second ply of resin to form a laminate;

curing the laminate in an autoclave to form an intermediate composite panel; and

submerging the intemiediate composite panel in a proteases enzymes solution that dissolves the filament to create the porous composite panel;

wherein the laminate is placed in a vacuum bag before it is cured in the autoclave;

wherein the filament is a chromic gut suture;

wherein the resin is pre-impregnated graphite epoxy resin.

2. The method of claim 1 wherein the filament includes a first filament and a second filament.

3. The method of claim 2 wherein a diameter of the first filament is greater than a diameter of the second filament.

4. The method of claim 2 wherein the laminate includes a third ply of resin and a fourth ply of resin, the third ply being laid atop the second ply and the fourth ply being laid atop the third ply.

5. The method of claim 4 further comprising the step of placing a third filament and a fourth filament on the third ply.

6. The method of claim 5 wherein a distance between the first filament and the second filament is greater than a distance between the third filament and the fourth filament.

7. The method of claim 5 wherein a diameter of the first filament is different from a diameter of at least one of the second filament, the third filament, and the fourth filament.

8. The method of claim 5 wherein the first filament and the second filament are respectively staggered with respect to the third filament and the fourth filament.

9. A method for manufacturing a composite panel having a desired void content comprising:

laying on a surface a first ply of resin, the first ply having a predetermined length and height;

provisionally dividing the first ply along its length into a first section and a second section;

placing on the first section a first filament and a second filament, a length of the first filament and a length of the second filament being at least equal to the height of the first ply;

placing on the second section a third filament and a fourth filament, a length of the third filament and a length of the fourth filament being at least equal to the height of the first ply, and a distance between the third filament and the fourth filament being greater than a distance between the first filament and the second filament;

laying a second ply of resin atop the first ply and the first, second, third, and fourth filaments to form a first intermediate composite panel;

curing the first intermediate composite panel in an autoclave to form a second intermediate composite panel; and

submerging the second intermediate composite panel in a solution that dissolves the first, second, third, and fourth filaments, leaving void space in their place;

wherein:

the first, second, third and fourth filaments are chromic gut sutures;

a diameter of the first and second filaments is generally equal;

a diameter of the third and fourth filaments is generally equal and different from the diameter of the first and second filaments.

10. The method of claim 9 , further comprising the step of placing the first intermediate panel in a vacuum bag before it is cured in the autoclave.

11. The method of claim 10 , wherein the solution comprises proteases enzymes.

12. A method for making a multi-ply composite panel having a desired void volume comprising:

laying on a surface a first ply of resin, the first ply having a predetermined length and height;

provisionally dividing the first ply along its length into a first section, a second section, and a third section;

placing on the first section a first filament and a second filament, a length of the first filament and a length of the second filament being at least equal to the height of the first ply;

placing on the second section a third filament and a fourth filament, a length of the third filament and a length of the fourth filament being at least equal to the height of the first ply, and a distance between the third filament and the fourth filament being greater than a distance between the first filament and the second filament;

placing on the third section a fifth filament and a sixth filament, a length of the fifth filament and a length of the sixth filament being at least equal to the height of the first ply, and a distance between the fifth filament and the sixth filament being greater than a distance between the third filament and the fourth filament;

laying a second ply of resin atop the first ply and the first, second, third, fourth, fifth and sixth filaments;

provisionally dividing the second ply along its length into a fourth section, a fifth section, and a sixth section, the fourth section being upwardly adjacent the first section, the fifth section being upwardly adjacent the second section, and the sixth section being upwardly adjacent the third section;

placing on the fourth section a seventh filament and an eighth filament, a length of the seventh filament and a length of the eighth filament being at least equal to the height of the second ply;

placing on the fifth section a ninth filament and a tenth filament, a length of the ninth filament and a length of the tenth filament being at least equal to the height of the second ply, and a distance between the ninth filament and the tenth filament being greater than a distance between the seventh filament and the eighth filament;

placing on the sixth section an eleventh filament and a twelfth filament, a length of the eleventh filament and a length of the twelfth filament being at least equal to the height of the second ply, and a distance between the eleventh filament and the twelfth filament being greater than a distance between the ninth filament and the tenth filament;

laying a third ply of resin atop the second ply and the seventh, eighth, ninth, tenth, eleventh, and twelfth filaments to form to form a first intermediate composite panel;

curing the first intermediate composite panel in an autoclave to form a second intermediate composite panel; and

submerging the second intermediate composite panel in a solution that dissolves each of the filaments.

13. The method of claim 12 wherein the first filament is not directly below the seventh filament or the eight filament.

14. The method of claim 13 , wherein the filaments comprise biologic material.

15. The method of claim 14 , wherein:

the filaments comprise chromic gut sutures; and

the solution comprises proteases enzymes.

16. The method of claim 15 further comprising the step of placing the first intermediate composite panel in a vacuum bag before it is cured.

17. The method of claim 16 , wherein the resin comprises graphite and epoxy.

18. A method for making a porous composite panel having a desired void content comprising:

forming a laminate; the laminate comprising a first ply of resin and a second ply of resin with an individual first suture and an individual second suture placed therebetween;

curing the laminate in an autoclave to form an intermediate composite panel; and submerging the intermediate composite panel in a proteases enzyme solution that dissolves the first suture and the second suture;

wherein the first suture and the second suture comprise chromic gut; and

wherein a diameter of the first suture is different from a diameter of the second suture.

19. The method of claim 18 wherein the laminate includes a third ply of resin laid atop the second ply and a third suture and a fourth suture placed therebetween.

20. The method of claim 19 wherein the first suture is staggered with respect to the third suture.

21. The method of claim 20 wherein a first distance between the first suture and the second suture and a second distance between the third suture and the fourth suture are unequal.

22. The method of claim 18 wherein the resin is pre-impregnated graphite epoxy resin.