Classifications

• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B5/00—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts
  • B32B5/02—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer
  • B32B5/12—Layered products characterised by the non- homogeneity or physical structure, i.e. comprising a fibrous, filamentary, particulate or foam layer; Layered products characterised by having a layer differing constitutionally or physically in different parts characterised by structural features of a fibrous or filamentary layer characterised by the relative arrangement of fibres or filaments of different layers, e.g. the fibres or filaments being parallel or perpendicular to each other
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B21/00—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board
  • B32B21/02—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board the layer being formed of fibres, chips, or particles, e.g. MDF, HDF, OSB, chipboard, particle board, hardboard
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B21/00—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board
  • B32B21/13—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board all layers being exclusively wood
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B21/00—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board
  • B32B21/14—Layered products comprising a layer of wood, e.g. wood board, veneer, wood particle board comprising wood board or veneer
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
  • E04F13/00—Coverings or linings, e.g. for walls or ceilings
  • E04F13/07—Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor
  • E04F13/08—Coverings or linings, e.g. for walls or ceilings composed of covering or lining elements; Sub-structures therefor; Fastening means therefor composed of a plurality of similar covering or lining elements
• • E—FIXED CONSTRUCTIONS
  • E04—BUILDING
  • E04F—FINISHING WORK ON BUILDINGS, e.g. STAIRS, FLOORS
  • E04F15/00—Flooring
  • E04F15/02—Flooring or floor layers composed of a number of similar elements
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/05—5 or more layers
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2250/00—Layers arrangement
  • B32B2250/40—Symmetrical or sandwich layers, e.g. ABA, ABCBA, ABCCBA
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/08—Coating on the layer surface on wood layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2255/00—Coating on the layer surface
  • B32B2255/26—Polymeric coating
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
  • B32B2260/02—Composition of the impregnated, bonded or embedded layer
  • B32B2260/028—Paper layer
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2260/00—Layered product comprising an impregnated, embedded, or bonded layer wherein the layer comprises an impregnation, embedding, or binder material
  • B32B2260/04—Impregnation, embedding, or binder material
  • B32B2260/046—Synthetic resin
• • B—PERFORMING OPERATIONS; TRANSPORTING
  • B32—LAYERED PRODUCTS
  • B32B—LAYERED PRODUCTS, i.e. PRODUCTS BUILT-UP OF STRATA OF FLAT OR NON-FLAT, e.g. CELLULAR OR HONEYCOMB, FORM
  • B32B2471/00—Floor coverings

Definitions

• Wood can be used to construct almost any part of a home from the roofing and exterior walls to the floor and interior architectural elements as well as basic domestic items like furniture and cabinets.
• the cost of solid timber wood has increased dramatically as its supply shrinks due to the gradual depletion of old-growth and virgin forests. Indeed, it is particularly expensive to manufacture solid hardwood furniture and architectural features from such material because typically less than half of harvested timber wood is converted to natural solid wood lumber, the remainder being discarded as scrap.
• wood-based alternatives to natural solid wood lumber have been developed that make more efficient use of harvested wood and reduce the amount of wood discarded as scrap.
• Plywood, particle board and oriented strand board (“OSB”) are examples of wood-based composite alternatives to natural solid wood lumber that have replaced natural solid wood lumber in many structural applications in the last seventy-five years. These wood-based composites not only use the available supply of timber wood more efficiently, but they can also be formed from lower-grade wood species, and even from wood wastes.
• wood-based composite materials do offer a highly efficient way to use available wood material, however, because they typically consist of small particles (particle board), wood strands (OSB), flat pieces of low-grade wood species or some similar such material, products made from them do not have an attractive, grained appearance, but rather tend to have unsatisfactory aesthetic finishes. This may make them unsuitable for use in interior furnishings and for articles of furniture and cabinetry.
• One approach to addressing this aesthetic drawback is to prepare a special wood composite material by placing decorative veneer layers having a wood or wood grain appearance upon the top and bottom surfaces of an internal, or “core” composite wood material.
• These veneer sheets are very thin, having a thickness of no greater than 1 ⁇ 8 inch, and are typically made from a decorative wood material, such as oak.
• Still another technique for preventing surface telegraphing is the application of a coating or putty to hide the texture or surface imperfections on the wood composite's surface, such as shown in U.S. Pat. No. 5,616,419.
• this technique not only often fails to prevent telegraphing, it is also time consuming to distribute the glue across the surface of the wood composite material in sufficient concentration and evenness to ensure that the surface telegraphing will be absent.
• the present invention includes a wood panel comprising: a composite wood component having upper and lower surface layers and a core layer; and a veneer component, having a thickness of about 1/64′′ inch to about 1 ⁇ 4′′, attached to the upper surface layer of the wood composite.
• the present invention also includes a process for preparing a wood panel comprising the steps of: providing a composite wood component, the wood component including an upper surface layer, the upper surface layer having an exterior face; providing a veneer component, having a thickness of about 1/64′′ inch to about 1 ⁇ 4′′; sanding the exterior face of the upper surface layer; applying an adhesive resin to the exterior face of the upper surface layer to form a resin applied exterior face; and contacting the veneer component to the resin applied exterior face to form a wood panel.
• wood is intended to mean a cellular structure, having cell walls composed of cellulose and hemicellulose fibers bonded together by lignin polymer.
• laminated it is meant material composed of layers and bonded together using resin binders.
• wood composite material or “wood composite component” it is meant a composite material that comprises wood and one or more other additives, such as adhesives or waxes.
• wood composite materials include oriented strand board (“OSB”), structural composite lumber (“SCL”), waferboard, particle board, chipboard, medium-density fiberboard, plywood, and boards that are a composite of strands and ply veneers.
• OSB oriented strand board
• SCL structural composite lumber
• waferboard particle board
• chipboard chipboard
• medium-density fiberboard plywood
• boards that are a composite of strands and ply veneers.
• flakes”, “strands”, and “wafers” are considered equivalent to one another and are used interchangeably.
• a non-exclusive description of wood composite materials may be found in the Supplement Volume to the Kirk-Othmer Encyclopedia of Chemical Technology, pp 765-810, 6 th Edition, which is hereby incorporated by reference.
• the following describes preferred embodiments of the present invention, which provides a wood panel comprising a wood composite component and a veneer component. Because the composite material piece does not display surface telegraphing through the veneer component, it is particularly useful for constructing furniture and cabinetry where a wood-grain appearance is important but where the use of solid timber wood would be prohibitively expensive.
• the wood veneer component may be selected from a variety of natural materials such as red oak, white oak, birch, maple, cherry, walnut, poplar, sweet gum, sycamore, tupelo, white gum, Carolina pine, ponderosa pine, lodgepole pine, Douglas fir, white fir, spruce, hemlock, rosewood, teak and mahogany.
• the veneers may be produced by standard veneer production techniques such as rotary slicing, rift-cut, quarter slicing, half-round slicing, plain slicing, and lengthwise slicing.
• the thickness of the veneer slice is between about 1/64′′ inch to about 1 ⁇ 4′′, more preferably between 1/42′′ inch and 1/16′′ inch.
• Suitable veneer materials are available from Clarke Veneers, Jackson Miss., as well as other distributors in North America through the HPVA (Hardwood Plywood and Veneer Association), Reston, Va.
• the thinness of the veneer varies somewhat with the material from which the veneer is constructed. For a material such as oak, the veneer must be at least 1/64′′, while for cherry the veneer could be as thin as 1/128′′.
• the veneer must be sufficiently thick that it can be sanded without damaging it, and also sufficiently thick that it is not necessary to attach a paper or other supporting backer to it to give it structural integrity.
• the veneer component may be treated with a protective, polymeric coating, with the coating cured by a technique selected from the group comprising UV-curing, RF curing, and E-band curing.
• the material may also be allowed to air dry.
• Suitable coatings include the UVN-700 coatings available from Valspar Corp., and the ZVOC Product line available from UV Corporation.
• the wood composite component is made from OSB material.
• the oriented strand board is derived from a starting material that is naturally occurring hard or soft woods, singularly or mixed, whether such wood is dry (having a moisture content of between 2 wt % and 12 wt %) or green (having a moisture content of between 30 wt % and 200 wt %).
• the raw wood starting materials either virgin or reclaimed, are cut into strands, wafers or flakes of desired size and shape, which are well known to one of ordinary skill in the art.
• the binder resin and the other various additives that are applied to the wood materials are referred to herein as a coating, even though the binder and additives may be in the form of small particles, such as atomized particles or solid particles, which do not form a continuous coating upon the wood material.
• the binder, wax and any other additives are applied to the wood materials by one or more spraying, blending or mixing techniques, a preferred technique is to spray the wax, resin and other additives upon the wood strands as the strands are tumbled in a drum blender.
• these coated strands are used to form a multi-layered mat, preferably a three layered mat.
• This layering may be done in the following fashion.
• the coated flakes are spread on a conveyor belt to provide a first ply or layer having flakes oriented substantially in line, or parallel, to the conveyor belt, then a second ply is deposited on the first ply, with the flakes of the second ply oriented substantially perpendicular to the conveyor belt.
• a third ply having flakes oriented substantially in line with the conveyor belt is deposited on the second ply such that plies built-up in this manner have flakes oriented generally perpendicular to a neighboring ply.
• all plies can have strands oriented in random directions.
• the multiple plies or layers can be deposited using generally known multi-pass techniques and strand orienter equipment.
• the first and third plys are surface layers, while the second ply is a core layer. The surface layers each have an exterior face.
• the above example may also be done in different relative directions, so that the first ply has flakes oriented substantially perpendicular to conveyor belt, then a second ply is deposited on the first ply, with the flakes of the second ply oriented substantially parallel to the conveyor belt. Finally, a third ply having flakes oriented substantially perpendicular with the conveyor belt, similar to the first ply, is deposited on the second ply.
• Suitable polymeric resins may be employed as binders for the wood flakes or strands.
• Suitable polymeric binders include isocyanate resin, urea-formaldehyde, polyvinyl acetate (“PVA”), phenol formaldehyde, melamine formaldehyde, melamine urea formaldehyde (“MUF”) and the co-polymers thereof.
• Isocyanates are the preferred binders, and preferably the isocyanates are selected from the diphenylmethane-p,p′-diisocyanate group of polymers, which have NCO-functional groups that can react with other organic groups to form polymer groups such as polyurea, —NCON—, and polyurethane, —NCOON—; a binder with about 50 wt % 4,4-diphenyl-methane diisocyanate (“MDI”) or in a mixture with other isocyanate oligomers (“pMDI”) is preferred.
• a suitable commercial pMDI product is Rubinate 1840 available from Huntsman, Salt Lake City, Utah, and Mondur 541 available from Bayer Corporation, North America, of Pittsburgh, Pa.
• Suitable commercial MUF binders are the LS 2358 and LS 2250 products from the Dynea corporation.
• the binder concentration is preferably in the range of about 3 wt % to about 8 wt %.
• a wax additive is commonly employed to enhance the resistance of the OSB panels to moisture penetration.
• Preferred waxes are slack wax or an emulsion wax.
• the wax solids loading level is preferably in the range of about 0.1 wt % to about 3.0 wt % (based on the weight of the wood).
• the surface layers in the present invention make use of the following enhanced resin composition.
• This resin composition involves the simultaneous application of an isocyanate resin and a powdered aromatic phenol-aldehyde thermoset material in the same blender in the preparation of the surface layers of the OSB.
• the powdered aromatic aldehyde thermoset effectively replaces a fraction of the MDI resin that otherwise would be needed.
• a powdered phenol-formaldehyde is used that penetrates very well inside curled flakes of the surface layer(s) of the OSB. It also enhances resin distribution inside the curled flakes in the surface layer of OSB to improve the board product quality by reducing curled flake failures without increasing resin costs.
• the MDI binder ingredient renders the OSB structurally strong and durable and generally improves the water resistance, while the phenol-formaldehyde ingredient prevents flake popping and improves strength of the OSB among other things.
• the resin binder system used for one or both the OSB surface layers, as initially reacted preferably is non-aqueous and contains no water or, at most, only nominal impurity levels (viz., less than 1 wt. % and preferably less than 0.5 wt. % water based on the total weight of the binder system). This resin composition and its methods for use are described in greater detail in U.S. Pat. No. 6,479,127.
• the multi-layered mats are formed according to the process discussed above, they are compressed under a hot press machine that fuses and binds together the wood materials, binder, and other additives to form consolidated OSB panels of various thickness and sizes.
• the high temperature also acts to cure the binder material.
• the panels of the invention are pressed for 2-15 minutes at a temperature of about 175° C. to about 240° C.
• the resulting composite panels will have a density in the range of about 35 lbs/ft 3 to about 48 lbs/ft 3 (as measured by ASTM standard D1037-98).
• the density ranges from 40 lbs/ft 3 to 48 lbs/ft 3 for southern pine, and 35 lbs lbs/ft 3 to 42 lbs/ft 3 for Aspen.
• the thickness of the OSB panels will be from about 0.6 cm (about 1 ⁇ 4′′) to about 5 cm (about 2′′), such as about 1.25 cm to about 6 cm, such as about 2.8 cm to about 3.8 cm.
• the exterior faces of the upper and lower surfaces are thoroughly sanded before the veneer components are attached to the upper and lower surfaces.
• this is done with a 120 grit or 60 grit sand paper.
• a minimum of 1/64′′ should be sanded from each side for a minimum total of 1/32′′.
• Suitable sanders are available from Timesavers, Inc., Minneapolis, Minn.
• blowers to remove the dust and particulates from the surface of the board, such blowers can be built into the sanding equipment.
• air knife or brush which applies a uniform flow of air across the surface of the board to remove particles or debris.
• Suitable air knives include the “Standard Air KnifeTM”, and the “Super Air KnifeTM” from the Exair Corporation, Cincinnati, Ohio. Air may be supplied either to the blowers mounted on the sanding equipment or to the air knife or air brush from an air compressor. Other methods for removing particulates, such as vacuums, are also acceptable.
• the engineered wood component e.g., the OSB panel prepared according to the aforementioned procedure
• the veneer component are attached to each other to form a composite piece.
• Such attachment occurs such as by adhesively bonding the veneer component to the exterior faces of the surface layers, such as by lamination.
• Common wood adhesives such as polyvinyl acetate, urea formaldehyde, MDI are applied to each of the components and the components brought into contact with each other to form an adhesive bond.
• the adhesives are applied at a concentration of about 6 g/ft 2 to about 20 g/ft 2 , preferably about 10 g/ft 2 to about 15 g/ft 2 .
• the components are brought into contact with each other using a typical 4′ ⁇ 8′ hot-press and held together for a period of about 1 minute to about 10 minutes, preferably about 2 minutes to about 5 minutes to establish a good adhesive bond.
• the press pressure was maintained of about 75 psi to about 200 psi, preferably about 120 psi to about 150 psi, and the press temperature was held at about 150° F. to about 300° F., preferably about 175° F. to about 225° F.
• the orientation of the attached wood veneer component relative to the wood composite component is important.
• the veneer component may be attached so that the grain direction of the veneer component is substantially parallel or substantially perpendicular to the strands on the exterior faces of the wood composite component.
• the preference for the orientation of the grain direction of veneer with respect to the strands in the surface layer of the OSB is determined by its end use. While it is preferred that the strands be oriented within a layer to provide stiffness and strength, it is understood by those skilled in the art that the strands can also be random, and the veneer grain direction would be oriented in a desirable direction with respect to the dimensions of the panel.
• the particulate matter was cleared off the board using blowers attached to the sanders and then further cleared with an airwand with 75 psi pressure.
• the Veneers used selected were from Clarke Veneers and included red oak P/S Grade A ( 1/42 inch thickness), natural birch rotary #1 ( 1/36 inch thickness), red oak rotary #1 ( 1/36 inch thickness), natural birch P/S grade A ( 1/42 inch thickness).
• the process parameters for adhesively bonding the veneer to the OSB were as follows:
• the surface profile of the panels was measured to determine smoothness and thus the degree to which the underlying OSB material “telegraphed” through the veneer.
• the surface profile was measured using a wood surface profiler.
• the surface profile was measured by the following procedure.
• a Mitutoyo SJ-201P (with a 0.75 inch sized detector) was used to make several measurements, in which a first measurement was made, and defined as the “datum” for that panel, and then several subsequent measurements made, and compared to the datum, with a positive measurement indicating a peak, and a negative measurement indicating a valley.
• the measurement system is capable of distinguishing not only the magnitude of the deviations, but also the direction of the differences themselves. (This processed is then repeated thrice for each board).
• RMS smoothness ( 1 N ⁇ ⁇ 1 N ⁇ Y i 2 )
• the composite wood component for the samples in Table I was Advantech® OSB made in Commerce, Ga.
• the PVA was obtained from Ashland Chemicals, specification CM 408, while the UF was obtained from Dynea Resin, specification Prefere 4213.
• the veneers used were 1/42 inch red oak P/S grade A, 1/36 inch red oak rotary #1, 1/42′′ natural birch P/S grade A, and 1/36 inch natural birch rotary #1. All the veneers used were from Clarke Veneers. TABLE II Wood Panels Prepared According to the present invention Veneer ?
• the composite wood component for the samples in Table II was Advantech® OSB made in White's Creek, Tenn.
• the PVA was obtained from Ashland Chemicals, specification CM 408, while the UF was obtained from Dynea Resin, specification Prefere 4213.
• the veneers used were 1/42 inch red oak P/S grade A, 1/36 inch red oak rotary #1, 1/42′′ natural birch P/S grade A, and 1/36 inch natural birch rotary #1. All the veneers used were from Clarke Veneers.
• the wood panels prepared according to the present invention performed very well compared to the industry standard materials.
• the panels made according to the present invention with oak veneers and PVA adhesive had lower measured RMS smoothness values after being exposed to the humidity conditioning test than all of the industry standard materials.
• the panels made according to the present invention with oak veneers and PVA performed better than the prior art industry standard materials.
• the panels made according to the present invention with oak veneers and UF adhesive also did very well, as can be seen by comparing their RMS smoothness values to those of the industry standard materials. Only the particle board with oak veneer industry standard material performed better than the panels of the present invention having oak veneers after the humidity conditioning test.
• Panels made according to the present invention with birch veneers also performed very well: consistently offering comparable performance to the prior art industry standard materials with birch veneer.
• the panels of the present invention can be easily made without time consuming and extra processing steps like the addition of extra material layers or the application of a resin or coating on top of the composite wood material, as is necessary in the prior art.

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• Engineering & Computer Science (AREA)
• Architecture (AREA)
• Life Sciences & Earth Sciences (AREA)
• Wood Science & Technology (AREA)
• Civil Engineering (AREA)
• Structural Engineering (AREA)
• Panels For Use In Building Construction (AREA)

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Cited By (11)

Citations (13)

• 2004
  • 2004-07-30 US US10/903,022 patent/US20060032167A1/en not_active Abandoned
• 2005
  • 2005-07-19 WO PCT/US2005/025552 patent/WO2006020284A2/fr active Application Filing

Patent Citations (14)

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