Patent Application
20100062233
The present disclosure relates generally to structural panels made substantially from paper as an alternative to conventional structural panels made substantially from wood (e.g., particle board) or substantially from a mineral material (e.g., gypsum board, also known as sheetrock or drywall). In one aspect, a structural panel in accordance with the present disclosure can be used as a building construction panel, as a structural layer in a laminated sandwich panel (e.g., a table top or countertop), or the like. In another aspect, a structural panel can be used as a shipping member used for shipping goods from one location to another, as an alternative to a traditional wood pallet.
Paperboard containers made from corrugated or non-corrugated paperboard are widely used for shipping products from manufacturers or distributors to retailers and other destinations. Other paper materials such as newsprint for advertising flyers, paper used as cushioning in cartons, and the like, are also widely used in industry. Once the paper materials have been used for their intended purpose, they are generally regarded as waste. In some cases, the used paper materials are simply disposed of along with other waste. In other cases, the user or recipient of the used paper materials may send the used paper materials to a recycler, at which the used paper materials are shredded and/or baled and then shipped to a paper mill. The paper mill can repulp the used paper materials to make recycled paper, which can then be converted into products of various types.
However, these recycling steps add significant cost to a material that is already of relatively low commercial value.
The shipping of products from manufacturers to distributors generally entails the use of shipping members (e.g., pallets, trays, etc.) for supporting and palletizing the products so that the products can easily be moved about using forklifts and the like. It is estimated that in the United States, presently there are approximately 1.4 billion pallets in circulation. The overwhelming majority of these pallets are conventional wood pallets made from wood boards nailed together. In the United States alone, approximately one million acres of timber go into the manufacturing of wood pallets per year. Wood pallets are difficult to dispose of after they have exhausted their useful life. It is estimated that approximately 120 million wood pallets are going to landfills each year. Currently it costs approximately one dollar per pallet to dispose of conventional wood pallets. Many landfills, however, are no longer accepting pallets. Thus, wood pallets represent a significant burden on the environment.
Apart from the environmental disadvantages, wood pallets are heavy, typically weighing as much as 70 pounds. As a consequence, a significant portion of the cost for shipping products is due to the weight of the pallets.
Additionally, wood pallets are relatively expensive to manufacture. The raw materials for a typical wood pallet cost approximately $4.50 to $5.75, to which the cost of labor for assembling the pallet must be added.
It is also common in the shipping of certain types of products to include protective members made from cardboard or paperboard in the carton. Such protective members can include, for example, L-shaped corner protectors, edge boards, and the like. Protective members made from paper typically are either disposed of after use, or are sent for repulping and recycling, which as already noted is not a very cost-effective way to reuse these used paper materials.
Furthermore, in the construction industry, structural panels comprising gypsum board (i.e., sheetrock or drywall) or particle board are widely used. Particle board is also used in the furniture industry.
A significant drawback associated with most or all of the aforementioned structural panels (particularly wood pallets and gypsum board) is that they are not readily recyclable in an economically attractive way.
The present disclosure describes an alternative manner of reusing used paper materials to make them into structural panels, thereby recycling them at reduced cost in comparison with the traditional recycling scheme involving repulping and papermaking. In accordance with the development described herein, a structural panel comprises a plurality of pieces of used paper material produced by dividing used paper material into pieces, with adhesive material being coated onto the pieces of used paper material, the coated pieces of used paper material being assembled together into a layer to form a structural panel. In some embodiments disclosed herein, the pieces are respectively randomly oriented in a multitude of different orientations within the layer.
A method for reusing used paper material (e.g., cardboard cartons, paper, etc.) comprises the steps of collecting the used paper material after the used paper material has been used for its primary purpose, dividing the used paper material into pieces, applying an adhesive material to the pieces, and assembling the pieces together to form a structural panel, the adhesive material binding the pieces together upon curing or drying of the adhesive material, whereby the structural panel is formed without repulping the used paper material. The structural panels can be used, for example, as pallets, as construction panels, as cores for sandwich panels (e.g., wall board, furniture panels, cabinet panels, countertops, etc.), and the like.
A significant advantage of the present development is that the used paper material can be “contaminated” paper material that conventionally is not readily recyclable, such as plastic-coated or wax-coated paperboard.
In one embodiment, the dividing step comprises dividing the used paper material into long narrow strips. The strips are bonded together with the adhesive material to form a structural panel, with the orientations of the strips being essentially random.
Advantageously the structural panel is made in a continuous process wherein the used paper material pieces coated with adhesive material are continuously deposited onto a moving surface to form a layer of the adhesive-coated pieces, and the layer is compressed between the moving surface and an upper member to consolidate the pieces and form the layer into a panel of desired thickness.
In one embodiment, the moving surface onto which the layer of adhesive-coated pieces is deposited comprises a sheet that will form one face sheet of a laminated structural panel. A second face sheet can be adhered to the opposite side of the layer, thus forming a three-layer laminated structural panel. The face sheets can comprise any of various materials. In one embodiment the face sheets comprise paper or paperboard made from recycled paper fibers. A laminated structural panel made in this manner can serve as a replacement for conventional gypsum board or particle board.
In a further embodiment, the dividing step comprises dividing the used paper material into substantially flat pieces larger than about 4×4 inches. The pieces are stacked to form a structural panel as a laminate made up of the pieces. At least some of the flat pieces can be of smaller width and/or length dimensions than the structural panel and can be stacked so as to partially overlap with one another.
In another embodiment, the dividing step comprises dividing the used paper material into pieces smaller than about 4×4 inches, and the pieces with the adhesive material are placed into a mold and pressed in the mold to form the structural panel. The mold can form the structural panel to be substantially planar, after which separate feet can be attached to the structural panel if it is to be used as a pallet. Alternatively, the mold can form the structural panel to have integral feet. The dividing step can comprise shredding the used paper material. Alternatively, the dividing step can comprise fiberizing the used paper material.
In accordance with the present disclosure, by omitting the typical repulping of the used paper material, the manufacture of recycled paper, and the converting operations for making paper products from the recycled paper, the added costs associated with these steps are avoided. Accordingly, additional use can be extracted from the used paper material at a substantially lower cost. The structural panels of the present invention can be made to possess a strength-to-weight ratio that compares very favorably with that of gypsum board and particle board, and it is expected that the manufacturing cost can also compare favorably in view of the low cost of the used paper material of which the panels are principally made.
Having thus described the invention in general terms, reference will now be made to the accompanying drawings, which are not necessarily drawn to scale, and wherein:
The present invention now will be described more fully hereinafter with reference to the accompanying drawings in which some but not all embodiments of the inventions are shown. Indeed, these inventions may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided so that this disclosure will satisfy applicable legal requirements. Like numbers refer to like elements throughout.
As used in the description and claims, “paper” means a sheet of one or more layers of material each formed by depositing an aqueous pulp of cellulose fibers (and optionally one or more additives such as clay, starch, etc.) onto a forming wire or the like and removing the water to form a layer as a network of the fibers held together by hydrogen bonding between the fibers. Thus, the term “paper” includes but is not limited to paper, paperboard, cardboard, and corrugated cardboard made from any suitable fibers. The term “used paper material” means paper that has already been used at least once for its originally intended purpose, and thus includes but is not limited to old corrugated cardboard (“OCC”), office waste paper, used non-corrugated cartons, and the like.
Conventionally, when a retailer empties paperboard cartons containing new products shipped to the retailer from the manufacturer or distributor, the cartons are flattened and when a substantial quantity of the flattened cartons and other used paper material have been collected, they are either trucked from the retailer to a landfill for disposal or are sold to a recycling center. The recycling center may shred the used paper material and then bale them, or may bale the used paper material without first shredding them, and the bales of used paper material are then shipped to a paper mill where they are used for making recycled paper products. The used paper material conventionally must be repulped in order to make new paper products.
The present development allows used paper material to be made into new useful products without having to repulp the used paper material. In particular, in accordance with the present development, used paper material is made into structural panels that can be used as shipping members such as pallets, trays, corner protectors, edge boards, and the like, as construction panels such as wall board, as furniture or cabinet panels, as table tops, as countertops, or the like.
The method of making a structural panel from used paper material basically entails dividing the used paper material into pieces by any of a number of suitable techniques as further described below, applying an adhesive material to the pieces, and then assembling the pieces together into a layer to form a structural panel. The adhesive material binds the pieces together upon curing or drying. In this manner, a structural panel is formed without repulping the used paper material.
A process and apparatus for making structural panels in accordance with one embodiment of the invention is shown diagrammatically in
In a first step of the process, the used paper material 20 is divided into pieces. Preferably a slitter 30 is employed to slit the used paper material into strips whose lengths are substantially greater than their widths. For example, the strips can have a length-to-width ratio between about 5:1 and about 50:1. When the used paper material is OCC, the slitter preferably slits the OCC such that the length direction of the strips is non-parallel to (and preferably perpendicular to) the direction in which the flutes of the corrugated layers extend. Slitting the OCC in this manner results in the strips having a plurality of “cells” formed between the corrugated layers and the face sheets.
Next, the strips of used paper material are fed into a drum mixer 40 or the like, along with adhesive material, and the strips are tumbled and mixed with the adhesive material so that the strips are sufficiently coated with adhesive material to allow them to adhere to one another. As an alternative to using a drum mixer, any other suitable device and technique can be used to achieve such coating of the strips.
The adhesive-coated strips of used paper material are then continuously deposited onto a moving surface such as a conveyor belt 50 to form a continuous layer 60 of the adhesive-coated strips. Any suitable technique and device can be used for continuously depositing the adhesive-coated strips. As one example, the strips can be depositing using a process similar to extruding, by pumping a stream of the adhesive-coated strips through a die slot or the like. The layer 60 can be deposited directly onto the surface of the belt 50 when the structural panel is to consist only of the layer 60. Alternatively, as shown, a continuous sheet 62 can be unwound from a roll and continuously fed onto the conveyor belt 50, and the layer 60 of adhesive-coated strips can be deposited onto the sheet 62. The adhesive on the strips may be sufficient to adhere the layer 60 to the sheet 62; alternatively, an additional adhesive can be applied to the surface of the sheet 62 before the adhesive-coated strips are deposited thereon. The layer 60 and sheet 62 form a continuous laminate.
A second continuous sheet 64 similarly can be unwound from a roll and continuously fed onto the upper surface of the layer 60 (again, either with or without application of additional adhesive to the sheet 64) in order to form a continuous three-layer sandwich panel having a core layer 60 of the adhesive-coated strips and face sheets 62, 64. The face sheets are useful for providing smooth surfaces to the sandwich panel, and also can enhance the bending stiffness of the panel.
The continuous panel is advanced by the conveyor belt 50 through a nip defined between a lower pressure member 52 and an upper pressure member 54. The nip has a predetermined thickness corresponding to the desired thickness of the panel. In the illustrated embodiment each of the pressure members comprises a roller. Furthermore, there is a series of three pairs of rollers 52, 54. The series of nip roller pairs can define progressively smaller nip thicknesses for progressively compressing the panel in three steps. Alternatively, any other suitable device can be used for compressing the panel to consolidate the layer of adhesive-coated strips and to achieve the desired thickness for the panel.
Although not shown, it will be understood that the apparatus and process can also employ any suitable type of heating/drying device for speeding up the drying or curing of the adhesive material used in the panel.
Finally, the continuously formed advancing panel is cut to any desired length by a suitable cutting device 70. Additionally, further cutting devices (not shown) can be used for trimming off side edge portions of the panel to form clean planar side edges, if desired. The resulting structural panel 100 can be used in various applications. For example, the panel 100 can replace conventional gypsum board or sheetrock, and can offer distinct advantages over gypsum board. In particular, the panel 100 is formed from used paper material, which is a renewable resource, unlike the calcined gypsum plaster used in the core of conventional gypsum board. Additionally, when the proper adhesive is used in sufficient amount for coating the used paper material strips, the panel 100 can achieve substantial water resistance and/or fire resistance. Advantageously, a silicate adhesive such as sodium silicate adhesive can be used for such purposes.
The exemplary panel shown in
As noted, the structural panels can be used in various construction, furniture, cabinet, or similar applications where gypsum board or particle board are conventionally used. The structural panels in accordance with the present invention can also be used as shipping members such as a pallet.
After a suitable adhesive material is applied to the cut pieces 122, 124, the pieces are stacked one atop another and fitted together in such a fashion that each of the various layers formed by the pieces is of generally uniform thickness, to the extent possible. Each of the pieces generally will partially overlap one or more other pieces. Once the desired total thickness has been built up from the pieces, the entire structure can be compressed by a suitable technique such as by placing the structure between two flat plates and using clamps or other mechanism to press the plates together for a period of time sufficient for the adhesive material to at least partially dry or cure. Pressing could be augmented by heating the plates to dry or cure the adhesive material more quickly and achieve better consolidation of the material.
Any of various adhesive materials can be employed. Suitable examples include but are not limited to water-based adhesives such as dextrin, PVA, sugar adhesives, and sodium silicate adhesives, or thermoset materials such as urea-formaldehyde (UF) resin typically used in the manufacture of particle board.
A second embodiment of a pallet is illustrated in
A shipping member 160 in accordance with a further embodiment of the invention is illustrated in
A shipping member 180 in accordance with another embodiment of the invention is shown in
In the shipping members 120, 140, 160, 180 described above, the manufacture of the deck has been described. In some cases, however, the shipping members will require either feet or integral slots in their lower surfaces to allow the tines of a forklift device to be inserted for lifting the shipping member and its load. Accordingly, for any of the shipping members described above, separate feet (not shown) can be made and then affixed to the lower surfaces of the decks using adhesive material. The feet can be made from the used paper material by cutting the used paper material into pieces or strips and adhesively joining the pieces or strips together. As one example, strips of used paper material can be cut and bonded together end-to-end to form a long continuous strip, and the strip can be coated with adhesive material and wound in convolute fashion to form a generally cylindrical foot that can be adhered to a deck. Other methods for forming feet can also be used.
As an alternative to using separate feet, integral slots can be formed in the lower surface of a shipping member deck for receiving forklift tines. The slots can be provided by cutting the pieces of used paper material used for laying up the deck such that the pieces have slots.
Another alternative for providing feet is to lay up the shipping member in a mold that is configured to form integral feet on the deck. After the used paper material pieces have been laid up in the desired fashion in the mold, the mold is closed and pressure is applied to cause the structure to substantially conform to the mold.
Molded shipping members can also be formed from used paper material that has been shredded or fiberized. For example,
Another molded shipping member 210 is shown in
A shipping member 220 in accordance with a further embodiment of the invention is shown in
In accordance with a method aspect of the invention, when a recipient of paperboard containers filled with new products empties the containers, which then become used paper containers (used paper material), the used paper material is collected. Then, either at the recipient's location or at another location, the used paper material is divided into pieces, the pieces are coated with adhesive material, and the pieces are assembled together to form a shipping member. The shipping members can then be sold to manufacturers and distributors for their use in shipping.
Shipping members such as pallets, trays, corner protectors, edge boards, and the like, and structural panels such as wall boards, furniture or cabinet panels, table tops or countertops, and the like, can be made in accordance with the invention from old corrugated containers (OCC) entirely, predominately (i.e., at least 50% OCC by weight), or partially (i.e., less than 50% OCC by weight). When OCC is mixed with other paper materials to make the shipping members, the other paper materials can comprise one or more of non-corrugated paperboard, various types of paper (e.g., newsprint, packing/cushioning paper, etc.), paper insulation material, and the like. For example, the OCC can be mixed with shredded or fiberized used paper material.
Many modifications and other embodiments of the inventions set forth herein will come to mind to one skilled in the art to which these inventions pertain having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the inventions are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the appended claims. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/US08/03080 | 3/7/2008 | WO | 00 | 9/1/2009 |
