Patent Application
20080220276
The present device relates to laminate boards having a veneered outer surface, such as a kitchen cutting board and the like. Particularly, the present device relates to a veneered board having a resin-impregnated core.
A cutting board is a general term used to describe a kitchen utensil which provides a flat surface on which to cut or slice food items. Such boards, for purposes of the present application, include chopping blocks, carving boards, cheese boards, serving boards, and the like. Cutting boards are often made of wood or plastic, and some chopping boards are made of glass-which is easier to clean than wood or plastic, but can be damaging to knives.
Wood boards are preferred over plastic and glass for several reasons. It has been shown that wood surfaced boards inhibit bacterial growth on the cutting surface, whereas plastics do not. Wood boards can be made from a variety of beautifully-grained hardwoods and softwoods, with maple and pine being the most popular, which may give a kitchen a much more attractive look than plastic boards. The wood board is less damaging to a sharp knife, even very good knives, than a glass board. The natural grain of the wood also helps keep the food from slipping, while plastic and glass surfaces must be textured to achieve this feature.
However, with the growing scarcity and cost of quality lumber, the fabrication of a dimensionally stable and inexpensive composite board has long been a challenge to the wood products industry. Layer separation, warping, instability of materials due to moisture, leaching of materials, expensive manufacturing processes and other problems have plagued attempts in the industry to create a suitable composite cutting board.
The cutting board of this invention has overcome prior art problems and provides an inexpensive, easily constructed, dimensionally stable cutting board capable of withstanding continued use and exposure to moisture and other elements encountered in a household. Disclosed is a board which is decorative, yet functional; versatile as a board for cutting, slicing, chopping and serving any number of food items; and is easy and inexpensive to manufacture.
In a first embodiment of the disclosed laminate structure, a cutting board comprises a core made of a resin-impregnated cellulosic material and a first wood veneer bonded to an exterior of the core. A second wood veneer bonded to an exterior of the core opposite the first wood veneer may be used to create a double-faced laminate board. The use of multiple barrier layers interposed between the core and the wood veneers prevent leaching of resin material into the veneers.
It is an aspect of an embodiment of the present invention to provide the resin-impregnated cellulosic material as a phenolic-impregnated paper. Preferably, the core comprises a plurality of phenolic-impregnated papers. A second resin-impregnated cellulosic material provides the barrier protection between the veneer and core layers. Preferably, the resin-impregnated barrier layer comprises one of either a fast-cycle melamine-impregnated paper, an acrylic-impregnated paper, or some combination of the two.
It is also an aspect of the present invention to provide a method of constructing a cutting board comprising the steps of arranging a laminate, heating the laminate to a temperature in the range of from about 285° F. (141° C.) to about 350° F. (177° C.), preferably about 305° F. (152° C.), and applying pressure within the range of from about 300 psi (20.7 bar) to about 1200 psi (82.7 bar), preferably about 500 psi (34.5 bar), to the laminate for a time. The laminate preferably comprises a core made of a resin-impregnated cellulosic material, a first wood veneer adjacent the core, a second wood veneer adjacent the core opposite the first wood veneer, and at least one barrier layer interposed between the core and at least one of either the first wood veneer and the second wood veneer. Preferably, the resin-impregnated cellulosic material is phenolic-impregnated paper and the barrier layers are selected from at least one of acrylic-impregnated paper, melamine-impregnated paper, and any combination of these papers.
These and other aspects of the invention may be understood more readily from the following description and the appended drawings.
For the purpose of facilitating an understanding of the subject matter sought to be protected, the accompanying drawings illustrate embodiments thereof, from an inspection of which, when considered in connection with the following description, the subject matter sought to be protected, its construction and operation, and many of its advantages should be readily understood and appreciated.
While this invention is susceptible of embodiments in many different forms, there is shown in the drawings and will herein be described in detail a preferred embodiment of the invention with the understanding that the present disclosure is to be considered as an exemplification of the principles of the invention and is not intended to limit the broad aspect of the invention to embodiments illustrated.
Referring to
Generally speaking, the cutting board 10, as show in
The core 12 is comprised of a plurality of cellulosic material sheets, such as those made from paper, cardboard, wood, and other fibrous plant material. The core 12 may be formed as a laminate itself prior to the construction of the laminate board or, as is preferred, it may be constructed as part of the board 10, as will be discussed in more detail below. The paper of the core 12 is preferably standard kraft paper which, as known by those skilled in the art, may vary in dimensional thickness. Thicknesses which are readily impregnated with a resin are preferred. The individual paper sheets 18 of core 12 are most preferably phenolic-impregnated paper manufactured and sold by Fiberesin Industries, Inc., Oconomowoc, Wis. The number of paper sheets 18 used for the core 12 depends on the desired thickness and strength of the resulting board 10. The number of paper sheets 18 preferably falls within the range of 4-60 sheets.
The resin of the core 12 has a tendency, especially under pressure, to leach into adjacent layers of the cutting board 10 during processing. Accordingly, a barrier layer 14 may be interposed between the core 12 and any additional layers to prevent leaching. The barrier layer 14 is also preferably a resin-impregnated cellulosic material, but may be a coated material in certain applications. A single sheet of material may be used for barrier layer 14, with the preferred layer being comprised of at least one of either acrylic-impregnated paper, styrene-butadiene impregnated paper, acrylic-coated paper, catalyzed (fast or slow cycle) melamine-impregnated paper, and blends thereof. Fast-cycle (highly catalyzed) melamine-impregnated paper is the most preferred material for use as a barrier layer. Low and very low level catalyzed melamine resins are not as effective barrier papers, and may require multiple sheets for a proper barrier layer. The melamine-impregnated paper with about 50-70% resin content has been found, based on the method described below, to most readily bond to the core and protect against leaching of the phenolic resin.
The third layer of the laminate is wood veneer 16. This layer is largely decorative, giving the resulting board an outwardly wood look and feel. The wood veneer 16 may be either a hardwood, preferably maple, or even a softwood, like pine, in some applications. Also, the veneer 16 is preferably applied as a sheet having a width greater than 3 inches (7.6 cm), and most preferably a sheet having a width equal to that of the desired board 10. Alternatively, the veneer 16 may take the form of wood strips no more than about 3 inches (7.6 cm) wide. The strips would need to be tightly aligned at abutting edges and could alternate different woods, grain patterns, and the like, for aesthetic purposes.
Referring now to the drawings of
Similarly,
Referring to
Finally,
Each of the disclosed embodiments of
A batch press machine (not shown) is used to manufacture the raw cutting board 10 of
The upper and lower plates of the press machine are preferably heated to within the desired temperature range for operation. A first veneer 16 is placed onto the lower plate of the batch press machine (not shown) and is then overlayed with a single sheet of resin-impregnated barrier paper 14. In some instances more than a single barrier sheet may be needed to prevent core resin bleed-through. The desired number of core resin-impregnated papers 18 are then aligned within the press machine to achieve a desired board thickness. As stated previously, though not preferred for present applications, the core 12 may be initially constructed as a laminate before being placed within the board 10 construction. Another barrier layer 14 then follows the core 12, and a second veneer 16 completes the construction.
The press is then activated to apply a pressure to the construction of approximately 500 psi, at least preferably within the range of 300 to 1200 psi, with the temperature of the press plates being held in the 285-350° F. range, preferably at 305° F. The curing of the impregnated resins is an exothermic reaction, so close monitoring of the temperature may be required. The press is held within these parameters for approximately 11 minutes to produce the finished laminate board.
The press plates are then opened and the resulting laminate board is removed and finished for retail. The finish process may include trim-cutting excess material, shaping edges of the board, sanding outer and edge surfaces, cleaning outer surfaces, treating, sealing, and trimming out the board for use and other necessary processes known to those skilled in the art.
The matter set forth in the foregoing description and accompanying drawings is offered by way of illustration only and not as a limitation. While particular embodiments have been shown and described, it will be apparent to those skilled in the art that changes and modifications may be made without departing from the broader aspects of applicants' contribution. The actual scope of the protection sought is intended to be defined in the following claims when viewed in their proper perspective based on the prior art.
