COMPOSITE PANEL AND METHOD FOR FORMING THE SAME

1 . A panel for use on a trailer, the panel comprising:

a panel member core with a length and comprising a first segment of thermoplastic foam extending the length and a second segment of thermoplastic foam extending the length adjacent the first segment, the first segment having a first density and the second segment having a second density, the first density being greater than the second density; and

a sheet extending over the first and second segments and laminated to the panel member core;

the panel member core being formed by extrusion.

2 . The panel of claim 1 , wherein the panel member core is formed by extruding a first stream of thermoplastic foam with the first density from a first extruder and thermally welding the first stream with a second stream of thermoplastic foam with the second density extruded from a second extruder to form the first and second segments, respectively

3 . The panel of claim 2 , wherein the first stream has a first thickness and the second stream has a second thickness, wherein the first thickness is substantially equal to the second thickness.

4 . The panel of claim 1 , wherein the panel member core is formed by extruding thermoplastic foam with a first region having a first thickness and a second region having a second thickness from an extruder, the first thickness being greater than the second thickness, and compressing at least the first region to form the first and second segments, respectively.

5 . The panel of claim 1 , further comprising a third segment extending the length, adjacent the second segment and opposite the first segment.

6 . The panel of claim 5 , wherein the third segment has the first density.

7 . The panel of claim 5 , further comprising a fourth segment extending the length, adjacent the third segment and opposite the second segment.

8 . The panel of claim 7 , wherein the fourth segment has the second density.

9 . The panel of claim 7 , further comprising a fifth segment extending the length, adjacent the fourth segment and opposite the third segment.

10 . The panel of claim 9 , wherein the fifth segment has the first density.

11 . The panel of claim 1 , wherein the first density is in the range of about 14 lb/ft 3 to about 30 lb/ft 3 .

12 . The panel of claim 1 , wherein the second density is in the range of about 1 lb/ft 3 to about 13 lb/ft 3 .

13 . A method of forming a panel for use on a trailer, the method comprising:

extruding a panel member core of thermoplastic foam with a first region having a first density and a second region, adjacent the first region, having a second density less than the first density;

cutting the panel member core at a predetermined length; and

laminating a sheet to the panel member core, extending over the first and second regions.

14 . The method of claim 13 , further comprising a third region adjacent the second region, opposite the first region, the third region having the first density; and

wherein the sheet extends over the first, second, and third regions.

15 . The method of claim 13 , wherein the first region of thermoplastic is extruded from a first extruder and the second region of thermoplastic is extruded from a second extruder, the method further comprising thermally welding the first region with the second region.

16 . The method of claim 13 , wherein the first region of thermoplastic is extruded with a first thickness and the second region of thermoplastic is extruded with a second thickness, wherein the first thickness is greater than the second thickness, the method further comprising compressing at least the first region to form a panel member core with a uniform thickness.

17 . The method of claim 13 , wherein the method further comprises:

heating the first region after the sheet is laminated to the panel member core; and

compressing the heated first region to increase the density.

18 . A method of forming a panel member core with a length for a panel to be used on a trailer, the method comprising:

extruding a first region, a second region, a third region, a fourth region, and a fifth region to extend along the length in parallel;

the first, third, and fifth regions being configured to have a greater density than the second and fourth regions; and

cutting the extruded first, second, third, fourth, and fifth regions at the length.

19 . The method of claim 18 , wherein the method further comprises thermally welding the first, second, and third regions the fourth and fifth regions.

20 . The method of claim 18 , wherein the method further comprises compressing the first, second, and third regions.