Method of forming a composite door structure
View Patent ↗A method of forming a composite door is disclosed. The method comprises: mixing together a thermoplastic polymer with an organic fibrous material in a ratio such that the organic fibrous material constitutes 40 to 60 percent by weight of the mixture; extruding the mixture under heat and pressure to create a thin sheet form; cutting the sheet to a predetermined size; removing material from at least one surface of the sheet to create a homogeneous appearance devoid of obvious fibrous particles; thermoforming the sheet to impart to the at least one surface an exterior three dimensional door surface to create a thin door facing; and assembling two of the thermoformed thin door facings, a peripheral frame and a core material into a door.
1. A method of forming a door comprising:
forming a peripheral door frame;
mixing a thermoplastic polymer with an organic fibrous material to form a mixture in a ratio such that the organic fibrous material constitutes 40 to 60 percent by weight of the mixture;
extruding the mixture under heat and pressure to form a thin sheet;
cutting the sheet to a predetermined size;
thermoforming the sheet to impart on at least one surface an exterior three dimensional door surface to define a thin door facing; and
assembling two of the thermoformed thin door facings, and a peripheral frame into a door in which the two thin door facings are fixedly held in parallel relation by the peripheral frame.
2. The method according to claim 1 , wherein the thermoplastic polymer is polypropylene.
3. The method according to claim 1 , wherein the organic fibrous material contains wood fiber.
4. The method according to claim 3 , wherein the organic fibrous material contains a mixture of wood fiber and other fibrous organic materials.
5. The method according to claim 1 , wherein the step of extruding the mixture creates a continuous sheet form having a first pair of opposed parallel edges substantially defining the peripheral width of the thin door facing, wherein the step of cutting the sheet includes cutting the continuous sheet between the first pair of opposed parallel edges to provide the thin door facing with opposed edges defining the height thereof.
6. The method according to claim 1 , further comprising:
removing material from at least one surface of the sheet to create a homogeneous appearance devoid of obvious fibrous particles.
7. The method according to claim 6 , wherein the step of removing the material includes sanding the at least one surface.
8. The method according to claim 6 , wherein the step of removing the material includes performing a corona treatment on the at least one surface.
9. The method according to claim 1 , wherein the step of thermoforming includes vacuum forming.
10. The method according to claim 1 , wherein the step of thermoforming includes imparting a wood grain configuration to the at least one surface.
11. The method according to claim 1 , wherein the step of thermoforming includes imparting a multiple paneled configuration to the at least one surface.
12. The method according to claim 1 , wherein the step of assembling further includes locating a core material in a cavity formed by the two thin door facings and the peripheral frame.
13. The method according to claim 12 , further comprising:
applying an adhesive to an inner surface of each of the door facings to secure the facings to at least one of the peripheral frame and the core material.
14. The method according to claim 13 , further comprising:
removing material from the inner surface of each of the door facings prior to applying the adhesive to the inner surfaces.
15. The method according to claim 1 , wherein the mixture includes a coupling agent.
16. The method according to claim 15 , wherein the coupling agent constitutes 0.5 to 5 percent by weight of the mixture.
17. The method according to claim 1 , further comprising:
applying a thin layer of plastic material to the thin sheet to form an exterior surface.
18. The method according to claim 17 , wherein applying the thin layer of plastic material includes coextruding a plastic material with the mixture to form a thin layer on the thin sheet.
19. The method according to claim 18 , wherein the thin sheet and the thin layer are thermoformed to form an exterior three dimensional door surface.
20. The method according to claim 17 , wherein applying the thin layer of plastic material includes laminating a thin layer of plastic material on the thin sheet.
21. The method according to claim 20 , further comprising treating an exterior surface of the thin sheet prior to laminating.
22. The method according to, claim 21 , wherein treating the exterior surface includes flame treating the exterior surface prior to laminating.
23. A method of forming a door comprising:
mixing a polypropylene with an organic fibrous material to form a mixture;
extruding the mixture under heat and pressure to create a thin sheet form;
cutting the sheet to a predetermined size;
thermoforming the sheet to impart to the at least one surface an exterior three dimensional door surface to define a thin door facing; and
assembling two of the thermoformed thin door facings, and a peripheral frame into a door in which the two thin door facings are fixedly held in parallel relation by the peripheral frame.
24. The method according to claim 23 , wherein the organic fibrous material constitutes 40 to 60 percent by weight of the mixture.
25. The method according to claim 24 , wherein the mixture includes a coupling agent, wherein the coupling agent constitutes 0.5 to 5 percent by weight of the mixture.
26. The method according to claim 23 , wherein the organic fibrous material contains wood fiber.
27. The method according to claim 26 , wherein the organic fibrous material contains a mixture of wood fiber and other fibrous organic materials.
28. The method according to claim 23 , wherein the step of extruding creates a continuous sheet form having a first pair of opposed parallel edges substantially defining the peripheral width of the thin door facing, and the step of cutting includes cutting the continuous sheet between the first pair of opposed parallel edges to provide the thin door facing with opposed edges defining the height thereof.
29. The method according to claim 28 , wherein the step of extruding further comprises:
coextruding a plastic material with the mixture to form a thin layer on the thin sheet.
30. The method according to claim 29 , wherein the thin sheet and the thin layer are thermoformed to form an exterior three dimensional door surface.
31. The method according to claim 23 , further comprising:
laminating a thin layer of plastic material to the thin sheet to form an exterior surface.
32. The method according to claim 31 , further comprising treating an exterior surface of the thin sheet prior to laminating.
33. The method according to claim 23 , further comprising:
removing material from at least one surface of the sheet to create a homogeneous appearance devoid of obvious fibrous particles.
34. The method according to claim 33 , wherein the step of removing material includes sanding the at least one surface.
35. The method according to claim 33 , wherein the step of removing the material includes forming a corona treatment on the at least one surface.
36. The method according to claim 23 , wherein the step of thermoforming includes comprises vacuum forming.
37. The method according to claim 23 , wherein the step of thermoforming includes imparting a wood grain configuration to the at least one surface.
38. The method according to claim 23 , wherein the step of thermoforming includes imparting a multiple paneled configuration to the at least one surface.
39. The method according to claim 23 , wherein the step of assembling further includes locating a core material in a cavity formed by the two thin door facings and the peripheral frame.