ULTRA THICK BAMBOO-WOOD COMPOSITE PANEL, ULTRA THICK SOLID WOOD COMPOSITE PANEL AND MANUFACTURING METHODS THEREOF

• US 20110274872A1
• Filed: 12/22/2009
• Published: 11/10/2011
• Est. Priority Date: 12/24/2008
• Status: Active Grant

• Current Assignee: Research Institute of Wood Industry Chinese Academy of Forestry
• Original Assignee: Research Institute of Wood Industry
• Inventors: Yu, Wenji, Zhu, Rongxian, Zhou, Yue, Ren, Dinghua, Yu, Yanglun
• Granted Patent: US 8,747,987 B2
• Time in Patent Office: Days
• US Class Current: 428/106
• CPC Class Codes: B27D 1/04 to produce plywood or articles made therefrom; Plywood sheets making a layered veneer cutting block B27L5/00
• CPC Class Codes: B27D 1/06 Manufacture of central layers; Form of central layers see also B27M3/002 and B27M3/0026
• CPC Class Codes: B32B 21/14 comprising wood board or veneer
• CPC Class Codes: B32B 2307/50 having particular mechanical properties
• CPC Class Codes: B32B 2307/538 Roughness
• CPC Class Codes: B32B 2307/54 Yield strength; Tensile strength
• CPC Class Codes: B32B 2307/732 Dimensional properties
• CPC Class Codes: B32B 2607/00 Walls, panels
• CPC Class Codes: B32B 7/12 using interposed adhesives or interposed materials with bonding properties
• CPC Class Codes: Y10T 428/24 Structurally defined web or sheet [e.g., overall dimension, etc.]
• CPC Class Codes: Y10T 428/24058 including grain, strips, or filamentary elements in respective layers or components in angular relation
• CPC Class Codes: Y10T 428/24066 Wood grain
• CPC Class Codes: Y10T 428/24132 including grain, strips, or filamentary elements in different layers or components parallel
• CPC Class Codes: Y10T 428/24537 Parallel ribs and/or grooves

Abstract

The present invention provides ultra-thick bamboo/wood and solid wood composite panels, comprising core board, surface board and back board; said core board is composed of ultra-thick peeling veneers with the thickness of 6 to 12 mm, both said surface board and back board are made of bamboo or wood; said core board comprises several layers of said ultra-thick veneers, and the veneers of contiguous layer are assembled with parallel structure; glue layer is arranged between contiguous said veneers, the adhesive in the glue layer is the aqueous macromolecule isocyanate adhesive; said ultra-thick veneers of the core layer are the veneers with stress degradation treatment, i.e., punctate or line segment cracks are formed along the grain of said veneer loose side in each layer. The glue spread amounts of said composite panels are obviously less than that of the existing composite panels with the same thickness, and the composite panels are without warping or deformation. The present invention also provides the manufacturing method of the above composite panels.

Claims

1. An ultra-thick wood/bamboo composite panel, comprising core board, surface board and back board, wherein said core board is composed of several ultra-thick peeling veneers with the thickness of 6 to 12 mm;

both said surface board and said back board are made of bamboo;

the veneers of contiguous layer in said core board are assembled with parallel structure or cross structure;

said ultra-thick veneers constituting the core board are the veneers with stress degradation treatment, i.e. punctate or line segment cracks are formed along the grain of said veneer loose side in each layer;

a glue layer is arranged between contiguous said veneers.

2. An ultra-thick wood/bamboo composite panel according to claim 1, wherein for said cracks in the loose side of said veneer, the average length is in a range of 20 to 50 mm, and the average depth is from ¼

to ½

of said veneer thickness;

or,

the average length is in a range of 20 to 50 mm, the average depth is from ¼

to ½

of said veneer thickness, the average width is in a range of 0.2 to 3 mm, and the average distance between the cracks is from 5 to 50 mm.

3. An ultra-thick wood/bamboo composite panel according to claim 1, wherein the total thickness of said wood/bamboo composite panel is in a range of 45 to 90 mm.

4. An ultra-thick wood/bamboo composite panel according to claim 1, wherein for said wood/bamboo composite panel, the thickness ratio of the bamboo as surface board and back board to the wood is from 1:

10 to 2;

1.

5. An ultra-thick wood/bamboo composite panel according to claim 1, wherein said bamboo is the bamboo scrimber with the thickness of 5 to 20 mm, or the glued laminated bamboo with the same thickness.

6. An ultra-thick wood/bamboo composite panel according to claim 1, wherein the glue layer between the lamellar in said ultra-thick wood/bamboo composite panel is aqueous macromolecule isocyanate adhesive, and the glue spread amount is in a range of 80 to 300 g/m².

7. An ultra-thick wood/bamboo composite panel according to claim 1, wherein, the glue layer between the lamellar in said ultra-thick wood/bamboo composite panel is resorcinol adhesive, and the glue spread amount is in a range of 150 to 300 g/m².

8. A manufacturing method for ultra-thick wood/bamboo composite panel, comprising raw material preparation procedure, glue spreading procedure, assembling procedure, forming procedure and maintenance procedure,

(1) raw material preparation procedure

wherein the raw material preparation procedure includes the preparation of bamboo, peeling of veneer, the stress degradation treatment of veneer, and the glue regulating, wherein, the preparation of bamboo includes the preparation of bamboo scrimber and the preparation of glued laminated bamboo;

1.1 the bamboo is made into bamboo scrimber or glued laminated bamboo to be as surface board and back board;

1.2 the log is peeled into ultra-thick veneers with the thickness of 6 to 12 mm, punctate or line segment cracks are formed in the loose side of the veneer by stress degradation using stress degradation machine, after drying treatment, the moisture content of the veneer is in a range of 7 to 25%;

1.3 the adhesive used is aqueous macromolecule isocyanate adhesive, comprising main agent and cross linking agent, the main agent is styrene-butadiene latex, vinyl acetate-ethylene copolymer emulsion or polyacrylic acid emulsion, and the cross linking agent is polymerized isocyanate;

the amount of cross linking agent is from 5 to 20% of that of the main agent, after stirring uniformly, aqueous macromolecule isocyanate adhesive is formed;

or, the adhesive used is resorcinol adhesive, comprising main agent and curing agent, the main agent is linear resorcinol resin containing alcohol, and the curing agent is polyformaldehyde;

the amount of polyformaldehyde is 8 to 15% of that of main agent, after stirring uniformly, resorcinol adhesive is formed;

(2) glue spreading procedure

wherein aqueous macromolecule isocyanate adhesive or resorcinol adhesive is spread uniformly on the surface of the stress degraded wood veneer and on the surface of bamboo scrimber or glued laminated bamboo;

the glue spread amount in each glue layer is from 80 to 300 g/m² for aqueous macromolecule isocyanate adhesive, and the glue spread in each glue layer is from 150 to 300 g/m² for resorcinol adhesive;

(3) assembling procedure

wherein the bamboo scrimber or glued laminated bamboo and the stress degraded veneer are assembled with parallel structure or cross structure, several said stress degraded veneers are assembled together to form the core board, bamboo scrimber or glued laminated bamboo are placed on the two sides of the core board so as to be used as surface board and back board, and then a slab is formed;

(4) forming procedure

wherein said slab is sent to cold pressing machine to cold press, the cold pressing pressure is in a range of 1 to 5 MPa, the cold pressing time is in a range of 20 to 60 min, and the cold pressing temperature is room temperature.

9. A manufacturing method for ultra-thick wood/bamboo composite panel according to claim 8, wherein, the fifth procedure is arranged after the forming procedure:

(5) maintenance procedure

wherein said slab is stacked in the oven at a temperature of 60 to 120°

C. with a humidity of 60 to 98%, the maintenance time is in a range of 1 to 5 h, the maintenance pressure is in a range of 0.6 to 2 MPa.

10. A solid wood composite panel made of ultra-thick veneers, comprising surface layer of the two outer surfaces and core layer between the outer surfaces, and adhesive arranged between the veneers in each layer;

wherein,

said core layer is composed of several ultra-thick veneers with the thickness of 6 to 12 mm, said surface layer is composed of veneers with the thickness of 0.2 to 1.5 mm;

the ultra-thick veneers used in core layer are the veneers made by the peeling of log, and punctate or line segment cracks are formed in the direction along the grain of the loose side of the veneers.

11. A solid wood composite panel made of ultra-thick veneer according to claim 10, wherein, for cracks in the loose side of ultra-thick veneer used in said core layer, the average length is in a range of 20 to 50 mm, the average depth is ⅙

to ½

of the veneer thickness ;

or the average length is in a range of 20 to 50 mm, the average depth is ⅙

˜

½

of the veneer thickness, the average width is in a range of 0.2 to 3 mm and the average distance is 5 to 50 mm between the cracks.

12. A solid wood composite panel made of ultra-thick veneer according to claim 10, wherein, said core layer is composed of even-ply veneers, such as 2-ply, 4-ply, 6-ply, 8-ply, and so on, and the core layer is assembled with parallel structure or cross structure;

or

said core layer is composed of even-ply veneers, such as 2-ply, 4-ply, 6-ply, 8-ply, and so on, and the core board is assembled with parallel or cross structure;

a sub-surface layer, namely balanced layer, is arranged between said core layer and said surface layer veneer, the balanced layer is composed of veneers with the thickness of 1 to 3 mm, and the veneer of the sub-surface layer is arranged as vertical or interlaced to the wood grain of veneers in core board and surface layer;

or

said core layer is composed of odd-ply veneer, such as 3-ply, 5-ply, 7-ply, and so on, and the core layer is assembled with parallel structure or cross structure;

or

said core layer is composed of odd-ply veneer, such as 3-ply, 5-ply, 7-ply, and so on, said core layer is assembled with parallel or cross structure;

a sub-surface layer, namely balanced layer, is arranged between said core layer and said surface layer, said balanced layer is composed of veneers with the thickness of 1 to 3 mm, and the veneer of the sub-surface layer is arranged as vertical or interlaced to the wood grain of veneer in core layer and surface layer.

13. A solid wood composite panel made of ultra-thick veneer according to claim 12, wherein the two veneers with the loose side jointed relatively or one veneer in symmetrical centre of said core board are the middle core board, all the loose sides of the veneers in each layer outside of the middle core board are toward the middle core board, and the veneers are assembled symmetrically, with the grains parallel to the central two layers, or vertical or interlaced to the center two layers.

14. A solid wood composite panel made of ultra-thick veneer according to claim 10, wherein said core layer is made of inferiority wood, such as poplar, Chinese fir, cryptomeria, metasequoia or spruce;

said surface layer is made of teak, dalbergia hupeana or keruing wood.

15. A solid wood composite panel made of ultra-thick veneer according to claim 12, wherein said sub-surface board is composed of common veneers made of poplar, birch or eucalypt.

16. A manufacturing method for solid wood composite panel made of ultra-thick veneers, comprising the steps:

A. veneers manufacture

wherein the wood for making core layer veneers, is peeled into ultra-thick veneers with the thickness of 6 to 12 mm, and said veneers are untwined in the stress degradation equipment, punctate or line segment cracks being formed along the grain in the loose sides of the veneers, then the veneers are used as veneers for core layer;

the wood for making surface board, is peeled into veneers with the thickness of 0.2 to 1.5 mm, then the veneers are used as decorative veneers for surface board;

B. drying

wherein the veneers are dried until the moisture content is in a range of 8 to 15%;

C. glue spread

wherein double-sided sizing is carried out on the ultra-thick veneers of the core layer, and gluing is not on the veneers of the surface layer;

D. assembling

wherein all said sizing ultra-thick veneers are assembled to form the core layer, and two thin veneers of the surface layer are assembled symmetrically on the upper and lower surface of the slab as vertical or interlaced to the wood grain of the core board;

E. hot-pressing

the slab is hot pressed to become one flesh.

17. A manufacturing method for solid wood composite panel made of ultra-thick veneers according to claim 16, wherein sub-surface layer is comprised between said core layer and said surface layer, in the veneers manufacture procedure A, the wood for making the sub-surface board is peeled into veneers with the thickness of 1 to 3 mm;

in the drying procedure B, the veneers are also dried until the moisture content is in a rang of 8 to 15%;

in the glue spreading procedure C, the double-sided sizing is used;

then in the assembling procedure D, the veneers for the sub-surface layer are arranged between the core layer veneers and surface layer veneers as the wood grain vertical or interlaced to the wood grain of the core layer and the surface layer.

18. A manufacturing method for solid wood composite panel made of ultra-thick veneer according to claim 16, wherein, in the assembling procedure, said core layer is assembled as following:

the two veneers with the loose sides jointed relatively or one veneer in symmetrical centre of said core board are the middle core board, all the loose sides of the veneers in each layer outside of the middle core board are toward the middle core board, and the veneers are assembled symmetrically with the grains parallel to the central two layers, or vertical or interlaced to the central two layers.

19. A manufacturing method for solid wood composite panel made of ultra-thick veneer according to claim 16, wherein in the above process, the adhesive used is an urea-formaldehyde resins or melamine modified urea-formaldehyde resins, the hot-pressing time is in a range of 0.5 to 1.6 min/mm, the hot-pressing pressure is in a range of 0.7 to 2 MPa, the hot-pressing temperature is in a range of 120 to 160°

C., the glue spread amount is in a range of 150 to 300 g/m²;

or,

in the above process, the adhesive used is a phenolic-aldehyde adhesive, the glue spread amount is in a range of 150 to 300 g/m², the hot-pressing time is in a range of 0.5 to 2.0 min/mm, the hot-pressing temperature is in a range of 130 to 180°

C., the hot-pressing pressure is in a range of 0.7 to 2.0 MPa;

or,

in the above process, the adhesive used is isocyanate, the glue spread amount is in a range of 20 to 50 g/m², the hot-pressing time is in a range of 0.5 to 1.2 min/mm, the hot-pressing temperature is in a range of 90 to 130°

C., the hot-pressing pressure is in a range of 0.7 to 2.0 MPa.