Coated Corrugated Paper Beverage Can and Method for Making a Corrugated Paper Beverage Can

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional Application No. 63/672,254, filed Jul. 17, 2024. This application incorporates by reference the entire specification of U.S. Pat. No. 11,401,661.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

Not Applicable

THE NAMES OF PARTIES TO A JOINT RESEARCH AGREEMENT

Not Applicable

INCORPORATION-BY-REFERENCE OF MATERIAL SUBMITTED ON A COMPACT DISC

Not Applicable

BACKGROUND OF THE INVENTION

Field of the Invention

The invention relates to beverage containers made of renewably sourced biodegradable materials.

Description of the Related Art

Aluminum cans are a common beverage container. While aluminum is recyclable, aluminum is not a renewable resource. In addition, a common practice is to adhere a polyethylene layer to an inner surface of aluminum beverage containers. The polyethylene improves taste and helps to prevent seepage from failed aluminum joints. However, by comingling polyethylene and aluminum, the resulting can cannot be recycled.

Corrugated fiberboard, corrugated cardboard, or corrugated refer to the same type of packaging material consisting of a fluted corrugated sheet and one or two flat linerboards. Corrugated fiberboard is made on “flute lamination machines” or “corrugators” and is used for making corrugated boxes. The corrugated medium sheet and the linerboard(s) are made of kraft containerboard, a paperboard material usually over 0.25 millimeters (0.01 in) thick.

In the United States, common flute sizes are described by letter or “microflute.” FIG. 10 is a table describing common flute sizes.

BRIEF SUMMARY OF THE INVENTION

An object of the invention is to provide a coated corrugated paper beverage can and a method for making a corrugated paper beverage can that overcomes the disadvantages of the devices and methods of this general type and of the prior art.

With the foregoing and other objects in view there is provided, in accordance with the invention, a can for holding a beverage. The can includes a top, a bottom, and a paper wall. The top has a top edge. The bottom has a bottom edge. The paper stock wall has an upper edge and a lower edge, The paper stock wall is generally tube shaped with an interior surface. “Generally tube shaped” means that a horizontal cross section of the paper stock wall can in fact increase or decrease along the height of the paper stock wall and still be considered “tube shaped”. The upper edge contacts the top edge and the lower edge contacts the bottom edge. The coating is applied to at least the interior surface.

The paper wall can be made of paperboard treated with a waterproofing composition. The paper wall can be smooth or crimped. The paper wall can include a raised seam where the rolled paper wall is rolled over itself and joined to itself by a waterproof, watertight adhesive. In the case of the paper wall be crimped, a plurality of vertical creases are folded into the paper wall. The crimps can be folded over each other to form frustoconical sections at the top and or bottom of the paper wall.

The paper wall can be made of more than one layer of overlapping paperboard: i.e., an inner layer and an outer layer. The paper wall can be corrugated fiberboard in which case the outer layer is an outer linerboard, the inner layer is an inner linerboard and a corrugated layer of paper board, preferably, kraft containerboard. The corrugated layer is adhered to the outer linerboard and the inner linerboard. The corrugated layer can be adhered with typical waterproof adhesives or with the waterproofing composition.

With the foregoing and other objects in view there is provided, in accordance with the invention, a can for holding a beverage. The can includes a top, a bottom, and a paper stock wall. The top has a top edge. The bottom has a bottom edge. The paper stock wall has an upper edge and a lower edge, The paper stock wall is generally tube shaped with an interior surface. “Generally tube shaped” means that a horizontal cross section of the paper stock wall can in fact increase or decrease along the height of the paper stock wall and still be considered “tube shaped”. The upper edge contacts the top edge and the lower edge contacts the bottom edge. The coating is applied to at least the interior surface.

In accordance with the objects of the invention, the coating is applied to a top seam formed along the top edge and the upper edge.

In accordance with the objects of the invention, the paper stock wall can have an outer surface and the coating can be further applied to said outer surface.

In accordance with the objects of the invention, the top edge has a top rim and the upper edge is tucked within said top rim.

In accordance with the objects of the invention, the tube shape has a frustoconical top portion and/or a frustoconical bottom portion.

In accordance with the objects of the invention, the top can be paper stock. The top can treated with a coating of the waterproofing composition.

In accordance with the objects of the invention, the bottom can be made from paper stock. The bottom can be treated with a coating of the waterproofing composition.

In accordance with the objects of the invention, the paper wall and the bottom can be molded. In such a case the paper wall and the bottom are one piece: i.e., unibody.

In accordance with the objects of the invention, the bottom can be made of paper board with at least the inner surface coated with the waterproofing composition. The waterproofing composition can be added to the outer surface of the paper board bottom as well.

In accordance with the objects of the invention, the top can be made of paper board with at least the inner surface coated with the waterproofing composition. The waterproofing composition can be added to the outer surface of the paper board bottom as well.

In accordance with the objects of the invention, a method is provided for forming a can. The first step is providing a sheet of paper stock. The next step is corrugating the paper stock to form a corrugated paper stock sheet. The next step is cutting a corrugated wall shaped sheet from said corrugated paper stock sheet. The next step is bending said wall-shaped sheet into a corrugated tube shape wall with an upper edge, a lower edge, and an inner surface. The next step is attaching a top edge of a top to said upper edge. The next step is attaching a bottom edge of said bottom to said lower edge. The next step is applying a coating to said inner surface.

The method can include the step of crimping the top and/or bottom of the paper wall into a frustoconical shape.

The method can include the step of crimping the paper wall to place one or more vertical creases in the paper wall.

The method can include applying the coating to a joint between said top edge and said upper edge.

The method can include applying the coating to an outer surface of the tube shape.

Waterproofing Composition

In accordance with the objects of the invention, a composition is provided for waterproofing paper and cardboard. The composition includes a plant-derived wax having a melting point above the temperature for hot drinks, which is at least 60° C. The plant-derived wax should have similar processing qualities as low-density polyethylene (LDPE).

Sugarcane wax and rice bran wax are suitable types of plant-derived waxes. Sugarcane wax and rice bran wax are suitable coatings to waterproof paper because they have melting points above 60° C. and more preferably above 70° C. Sugarcane wax and rice bran wax have similar melting points as LDPE so pellets including sugarcane wax and/or rice bran wax can be used with existing machinery used to coat paper. While the waterproofing composition can include both rice-bran wax and sugarcane wax, a functioning waterproofing composition can be made with rice-bran wax and no sugarcane wax.

Accordingly a composition for waterproofing paper, can include a first plant-derived wax having a melting point above 70° C., a second plant-derived wax having a melting point above 70° C., and a surfactant. At least 99.6% by weight of the composition is formed by plant-derived waxes including at least said first plant-derived wax and said second plant-derived wax, and a group of surfactants including at least said surfactant. As stated, the first plant-derived wax can be sugarcane wax and the second plant-derived wax can be rice-bran wax. A food-grade surfactant, for example, calcium stearate can be added.

Other features that are considered as characteristic for the invention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodied in coated corrugated paper beverage can and method for making a corrugated paper beverage can, the invention should not be limited to the details shown in those embodiments because various modifications and structural changes may be made without departing from the spirit of the invention while remaining within the scope and range of equivalents of the claims.

The construction and method of operation of the invention and additional objects and advantages of the invention is best understood from the following description of specific embodiments when read in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a diagrammatic perspective view of a sheet of paper stock according to the invention.

FIG. 2 is a diagrammatic perspective view of a corrugated paper stock sheet made from the sheet shown in FIG. 1.

FIG. 3 is a diagrammatic perspective view of a corrugated wall shaped sheet cut from the corrugated paper stock sheet shown in FIG. 2.

FIG. 4 is a diagrammatic perspective view of a corrugated tube shaped wall being made from the corrugated wall shaped sheet shown in FIG. 3.

FIG. 5 is a diagrammatic perspective view of the corrugated tube shaped wall shown in FIG. 4.

FIG. 6 is an exploded diagrammatic perspective view of a can according to the invention.

FIG. 7 is a photograph showing a perspective view of a first embodiment of a can according to the invention.

FIG. 8 is a photograph showing a perspective view of a second embodiment of a can according to the invention.

FIG. 9 is a photograph showing a perspective view of a third embodiment of a can according to the invention.

FIG. 10 is a table describing standard sizes of flutes used in corrugated paper.

DETAILED DESCRIPTION OF THE INVENTION

In the Summary of the Invention above and in the Detailed Description of the Invention, and the claims below, and in the accompanying drawings, reference is made to particular features (including method steps) of the invention. It is to be understood that the disclosure of the invention in this specification includes all possible combinations of such particular features. For example, where a particular feature is disclosed in the context of a particular aspect or embodiment of the invention, or a particular claim, that feature can also be used, to the extent possible, in combination with and/or in the context of other particular aspects and embodiments of the invention, and in the invention generally.

The term “comprises” and grammatical equivalents thereof are used herein to mean that other components, ingredients, steps, etc. are optionally present. For example, an article “comprising” (or “which comprises”) components A, B, and C can consist of (i.e., contain only) components A, B, and C, or can contain not only components A, B, and C but also one or more other components.

Where reference is made herein to a method comprising two or more defined steps, the defined steps can be carried out in any order or simultaneously (except where the context excludes that possibility), and the method can include one or more other steps which are carried out before any of the defined steps, between two of the defined steps, or after all the defined steps (except where the context excludes that possibility).

The term “at least” followed by a number is used herein to denote the start of a range beginning with that number (which may be a range having an upper limit or no upper limit, depending on the variable being defined). For example, “at least 1” means 1 or more than 1. The term “at most” followed by a number is used herein to denote the end of a range ending with that number (which may be a range having 1 or 0 as its lower limit, or a range having no lower limit, depending upon the variable being defined). For example, “at most 4” means 4 or less than 4, and “at most 40%” means 40% or less than 40%. When, in this specification, a range is given as “(a first number) to (a second number)” or “(a first number)-(a second number),” this means a range whose lower limit is the first number and whose upper limit is the second number. For example, 25 to 100 mm means a range whose lower limit is 25 mm, and whose upper limit is 100 mm.

FIG. 1 shows a sheet 5 of paper stock. In one preferred embodiment, the sheet 5 is made of corrugated paperstock that includes a fluted corrugated sheet sandwiched between two flat linerboards. In a second preferred embodiment, the sheet 5 is made of a single sheet of paperboard. In a third preferred embodiment, the sheet 5 is made of two or more layers of paperboard.

FIG. 2 shows a crimped sheet 50 made from the sheet 5. The crimped sheet has a plurality of parallel creases.

FIG. 3 shows a corrugated wall shaped sheet 51 cut from the corrugated sheet 50. The height of the corrugated wall shaped sheet is approximate the height of the can plus additional height for forming rims and frustoconical portions. The width of the corrugated wall shaped sheet is approximately equal to the circumference of the can plus an additional amount for forming an overlapping portion. The corrugated wall shaped sheet 51 is rectangular.

FIGS. 4-5 show a corrugated tube-shaped wall 52 being formed from the corrugated wall shaped sheet 51. The corrugated tube-shaped wall 52 has an upper edge 40 and a lower edge 41. The corrugated tube-shaped wall 52 has an interior surface 42 and an outer surface 43.

FIG. 6 shows the corrugated tube-shaped wall 52 that has had a frustoconical top portion 11 and a frustoconical bottom portion 12 formed therein. An upper edge 40 is formed on the frustoconical top portion 11. A lower edge 41 is formed on the frustoconical bottom portion 12. A top 2 includes a top edge 20 with a descending top rim 21. A bottom 3 includes a bottom edge 30 with an ascending bottom rim 31. When assembled, the upper edge 40 is seated in the top rim 21 and the lower edge 41 is seated in the bottom rim 31.

FIGS. 7-8 show preferred embodiments of cans.

A preferred embodiment of a method for manufacturing corrugated paper beverage cans includes the following steps.

The first step is choosing a material. FIG. 1 shows a sheet 5 of paper stock. Preferred materials are paper stock that is heavy enough to retain its shape when empty and strong enough not to rupture when shipped and handled. A heavy ply paper is a preferred material for making beverage containers. A preferred grammage of paper is between 150 and 500.

The next step is applying a waterproofing composition to what will be an interior surface of the can. The waterproofing composition prevents liquid leakage and enhances durability.

The next step is corrugation and forming. This step includes feeding the sheet 5 of treated paper material through a stamping or embossing machine to apply a corrugated shape to the surface to produce a corrugated sheet 50 as shown in FIG. 2. The next step involves die-cast cutting the corrugated sheet 5 into a corrugated wall shaped sheet 51 as shown in FIG. 3, which can be formed into can shapes, resembling traditional soda cans.

The next step is assembling the can. The assembling includes rolling the corrugated wall shaped sheet 51 into a corrugated tube-shaped wall 52 while maintaining the corrugated ridges for structural support. After assembling, the next step is sealing the edges of the container securely to ensure liquid-tight integrity.

The next step is applying a barrier coating. The barrier coating is applied by adding an additional layer of waterproofing composition to the interior of the container to enhance liquid resistance and prevent seepage. Once the corrugated paper material has been formed into can shapes and securely sealed, the next step is applying the waterproofing composition to the inner surface 42 and outer surface 43 of the can. To apply the waterproofing composition, begin by melting pelletized waterproofing composition and then applying the molten coating evenly to the inner surface 42 of the can. The next step is cooling the waterproofing composition to harden the composition. Once cooled, the next step is forming a protective barrier against liquid leakage while maintaining the structural integrity of the containers.

An additional step is quality control and testing. Cans are pressure tested to make sure the containers do not deform under internal pressures at least as much as the pressures generated by carbonated beverages. An additional quality control and testing is performing leak tests to verify the effectiveness of the barrier coating in preventing liquid leakage.

The resulting biodegradable corrugated paper beverage containers offer a sustainable alternative to traditional plastic or metal cans, combining eco-friendly materials with innovative design for a more environmentally conscious packaging solution.

Waterproofing Composition

A preferred embodiment of a composition for waterproofing paper, paperboard, and cardboard includes a mixture of rice-bran wax, and calcium stearate. The rice bran wax forms from 95.0 to 99.6% of the composition by volume. Sugarcane wax can be included and forms from 0 to 4.6% of the composition by volume. The combined percentage of the sugarcane wax and the rice-bran wax totals no more than 99.6% of the waterproofing composition. The calcium stearate forms 0.4% of the composition by volume.

Additional ingredients that do not affect the waterproofing and adhesive qualities of the composition can be included. A dye or pigment is an example of an additional composition.

Although the present invention has been described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the preferred versions contained herein.

The reader's attention is directed to all papers and documents which are filed concurrently with this specification and which are open to public inspection with this specification, and the contents of all such papers and documents are incorporated herein by reference.

All the features disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

Any element in a claim that does not explicitly state “means for” performing a specified function, or “step for” performing a specific function, is not to be interpreted as a “means” or “step” clause as specified in 35 U.S.C. § 112, ¶16. In particular, the use of “step of” in the claims herein is not intended to invoke the provisions of 35 U.S.C. § 112, ¶16.