Low pressure melamine/veneer panel and method of making the same

• US 5,925,211 A
• Filed: 04/21/1997
• Issued: 07/20/1999
• Est. Priority Date: 04/21/1997
• Status: Expired due to Term

• Current Assignee: Nevamar Co. LLC (International Paper Company)
• Original Assignee: International Paper Company
• Inventors: Rakauskas, Michael E.
• Primary Examiner(s): Ball, Michael W.
• Assistant Examiner(s): Tolin, Michael A
• Application Number:
  US08/844,734
• Time in Patent Office: 820 Days
• Field of Search: 156/228, 156/306.6, 156/306.9, 156/307.1, 156/307.3, 156/307.4, 156/307.5, 156/307.7, 156/331.1, 156/331.5, 156/331.8, 428/511, 428/503, 428/534, 428/535, 144/348, 144/352
• US Class Current: 156/306.9
• CPC Class Codes: B27D 1/00 Joining wood veneer with any material; Forming articles thereby in conjunction with moulding of wood particles or fibres B27N3/06; Preparatory processing of surfaces to be joined, e.g. scoring
• CPC Class Codes: B32B 2038/0076 Curing, vulcanising, cross-linking
• CPC Class Codes: B32B 21/14 comprising wood board or veneer
• CPC Class Codes: B32B 2309/02 Temperature
• CPC Class Codes: B32B 2309/04 Time
• CPC Class Codes: B32B 2309/12 Pressure
• CPC Class Codes: B32B 2317/16 Wood, e.g. woodboard, fibreboard, woodchips
• CPC Class Codes: B32B 37/00 Methods or apparatus for laminating, e.g. by curing or by ultrasonic bonding
• CPC Class Codes: B32B 37/0015 to avoid warp or curl
• CPC Class Codes: B44C 5/043 containing wooden elements
• CPC Class Codes: B44C 5/0492 containing wooden elements
• CPC Class Codes: E04F 13/0871 having an ornamental or specially shaped visible surface E04F13/0867 takes precedence
• CPC Class Codes: Y10T 428/31866 Impregnated or coated cellulosic material
• CPC Class Codes: Y10T 428/31895 Paper or wood

Abstract

A layered composite product for use as a floorboard, a door, a cabinet, a wall, etc. is disclosed. The product is a layered structure that includes a rigid substrate layer having two substantially planar sides, a resin-saturated sheet layer disposed on each of the substantially flat sides, and a veneer layer disposed on at least one of the sheet layers. Also provided is a method of making the aforementioned product, the method comprising the steps of forming the layered structure, and then compressing the structure in a pressing apparatus for a time sufficient to cure the resin at under heat and pressure.

Claims

1. A method of producing a laminated composite article, said method consisting essentially of the steps of:

(a) forming a layered structure comprising a rigid substrate layer having two substantially flat sides, a resin-saturated sheet layer disposed on each of said sides, and a veneer layer disposed on only one of said sheet layers; and

,

(b) subjecting said structure to elevated temperature and pressure in a pressing apparatus for a time sufficient to cure said resin at said temperature and pressure.

2. The method of claim 1, wherein said pressing apparatus comprises a first platen and a second platen, said first platen having a temperature of about 350°

F. to about 405°

F., and said second platen having a temperature of about 320°

F. to about 350°

F.

3. The method of claim 1, wherein said pressing apparatus subjects the structure of step (a) to a pressure of about 325 psi to about 425 psi.

4. The method of claim 1, wherein said time is about one minute or less.

5. The method of claim 1, wherein said time is about 30 seconds to about 40 seconds.

6. The method of claim 1, wherein said resin of said resin-saturated sheet is a material comprising melamine.

7. The method of claim 6, wherein said resin of said resin-saturated sheet is a material comprising about 98 wt. % melamine.

8. The method of claim 6, wherein said resin of said resin-saturated sheet is a material comprising a melamine/urea blend.

9. The method of claim 8, wherein said resin of said resin-saturated sheet is a material comprising about 60 wt. % of melamine and about 40 wt. % of urea.

10. The method of claim 6, wherein said resin comprises about 45 wt. % to about 65 wt. % of the resin-saturated sheet.

11. The method of claim 1, wherein said sheet of said resin-saturated sheet is an alpha cellulose sheet having a basis weight of about 40 pounds per ream to about 100 pounds per ream.

12. The method of claim 1, wherein said rigid substrate layer is a material selected from the group consisting of particleboard, low-density fiberboard, medium-density fiberboard, and high-density fiberboard.

13. The method of claim 1, wherein said veneer layer comprises a wood material having a moisture content of about 7 wt. % to about 10 wt. % based on the weight of the veneer.

14. A method of producing a composite article, comprising the steps of:

(a) providing a rigid substrate layer having two substantially flat sides;

(b) providing, on each of said sides of the substrate layer, a sheet layer that is substantially saturated with a thermosetting resin;

(c) providing, on only one of said sheet layers, a veneer layer to form a lavered structure consisting essentially of said substrate layer, said sheet layers and said veneer layer;

(d) providing the layered structure of step (c) in a pressing apparatus; and

(e) subjecting the layered structure of step (d) to elevated temperature and pressure in said pressing apparatus for a period sufficient to cure said resin at said temperature and pressure.

15. The method of claim 14, wherein:

the product of step (c) is provided in a pressing apparatus including a first platen and a second platen; and

,

in step (e) said first platen has an elevated temperature in the range of about 350°

F. to about 405°

F., and said second platen has an elevated temperature in the range of about 320°

F. to about 350°

F.

16. A method of producing a laminated composite article, said method comprising the steps of:

(a) forming a layered structure comprising a rigid substrate layer having two substantially flat sides, a resin-saturated sheet layer disposed on each of said sides, and a veneer layer disposed on at least one of said sheet layers; and

,

(b) subjecting said structure to elevated temperature and pressure in a pressing apparatus for a time sufficient to cure said resin at said temperature and pressure, said pressing apparatus comprising a first platen and a second platen, said first platen operating at a temperature different from an operating temperature of said second platen.

17. The method of claim 16, wherein said operating temperature of said first platen is in a range of about 350°

F. to about 405°

F., and said operating temperature of said second platen is in a range of about 320°

F. to about 350°

F.

18. The method of claim 16, wherein said pressing apparatus subjects the structure of step (a) to a pressure of about 325 psi to about 425 psi.

19. The method of claim 16, wherein said time is about one minute or less.

20. The method of claim 16, wherein said time is about 30 seconds to about 40 seconds.

21. The method of claim 16, wherein said resin of said resin-saturated sheet is a material comprising melamine.

22. The method of claim 21, wherein said resin of said resin-saturated sheet is a material comprising about 98 wt. % melamine.

23. The method of claim 21, wherein said resin of said resin-saturated sheet is a material comprising a melamine/urea blend.

24. The method of claim 23, wherein said resin of said resin-saturated sheet is a material comprising about 60 wt. % of melamine and about 40 wt. % of urea.

25. The method of claim 21, wherein said resin comprises about 45 wt. % to about 65 wt. % of the resin-saturated sheet.

26. The method of claim 16, wherein said sheet of said resin-saturated sheet is an alpha cellulose sheet having a basis weight of about 40 pounds per ream to about 100 pounds per ream.

27. The method of claim 16, wherein said rigid substrate layer is a material selected from the group consisting of particleboard, low-density fiberboard, medium-density fiberboard, and high-density fiberboard.

28. The method of claim 16, wherein said veneer layer comprises a wood material having a moisture content of about 7 wt. % to about 10 wt. % based on the weight of the veneer.

29. The method of claim 16, wherein said veneer layer is disposed on only one of said sheet layers.

30. A method of producing a composite article, comprising the steps of:

(a) providing a rigid substrate layer having two substantially flat sides;

(b) providing, on each of said sides of the substrate layer, a sheet layer that is substantially saturated with a thermosetting resin;

(c) providing, on at least one of said sheet layers, a veneer layer;

(d) providing the product of step (c) in a pressing apparatus; and

(e) subjecting the product of step (d) to elevated heat and pressure in said pressing apparatus for a period sufficient to cure said resin at said temperature and pressure, said pressing apparatus comprising a first platen and a second platen, said first platen operating at a temperature different from an operating temperature of said second platen.

31. The method of claim 30, wherein:

in step (e) said operating temperature of said first platen is in a range of about 350°

F. to about 405°

F., and said operating temperature of said second platen is in a range of about 320°

F. to about 350°

F.