MXPA97002135A - Minimum board structure container and construction method - Google Patents

Abstract

The present invention relates to a container structure of minimal corrugated boarding structure characterized in that it comprises a structure in the form of a unitary and substantially flat ladder made from interlocking strips of a substantially rectangular shape of corrugated cardboard, said cardboard interfitting strips corrugated being held together by a joining means in the areas of overlap of said strips for substantially open forms in said stair-shaped structure, said stair-shaped structure having two ends, the stair-shaped structure having fold lines to be bent in said interlocking strips and able to connect at said two ends to form a shipping container.

Description

MINIMUM SHIPMENT CONTAINER AND METHOD OF CONSTRUCTION FIELD OF THE INVENTION The present invention relates to corrugated cardboard shipping containers, and more particularly to such containers wherein the upper, lower and side sides have large openings to reduce the material used and the weight of the container. Even more particularly, the present invention relates to such containers that are constructed by the joint fastening of corrugated cardboard strips, pre-cut.

BACKGROUND OF THE INVENTION Corrugated cardboard containers are commonly used to store and ship consumer durable and non-durable items from the manufacturer to the retail merchant. During storage and shipping, such containers are stacked one on top of the other at checkpoints or loading units. The piles are at least the height of the truck or railroad car, and can reach 30 feet or a little more in stores. Therefore, shipping containers not only protect their contents from dust and weather, but also typically provide sturdy columns to protect their contents from the weight of other containers stacked above them. The corrugated / laminate material of the shipping containers provide stiffness and column strength while being light in weight and low in cost. Typically, flat container parts are die cut from large sheets of corrugated cardboard, marked by bending, and formed into rectangular containers with fins, using glue or staples to secure the walls of the container at right angles to each other. These containers are commonly called Regular Slotted Containers. Historically, the additional reduction in the weight of corrugated cardboard containers has not been important because they are already lightweight. However, environmental pressures for source reduction, reduced packaging, and recycling of materials have caused the corrugated cardboard containers to be reexamined. A favorable approach in an environmental way has been to reuse each container several times. Such containers are commonly called Reembark Containers. The Reembarca Containers are built in a robust way to absorb the abuses of loading, unloading, and multiple boarding and storage situations. More recently, they have been made containers with large openings die-cut. Instead of reusing, these containers are intended for single use, but they have less material than regular slotted containers. Some of these containers are constructed from corrugated, free-form, multiple pieces, for specialized applications, such as shipping heavy tools. These can be made of wood support or metal frames to increase the structural rigidity. The large side openings can be wrapped with plastic film to protect the container contents from dust and weather. However, the specialized nature of such containers, with their manual assembly and high cost of waste from the die-cut corrugated forms, do not provide a low alternative cost for shipping or shipping for most consumer purposes. Other single-use, die-cut containers are essentially Regular Slotted Containers with portions of side panels removed by additional die cutting. Any material that is die-cut from a piece of cardboard becomes waste. Although such waste can be recycled, managed and recycled, waste has significant costs associated with it. What is needed is a minimum material container that has been formed without the generation of waste.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a minimum container made of corrugated cardboard strips, pre-cut, which are held together to form a lightweight rectangular frame container intended for single use only. The plastic film is wrapped around and connected to the rectangular frame, not only for protection against dust and weather, but also to improve structural rigidity. The total reduction of the minimum container from 50% to 80% of the container material, compared to Regular Slotted Containers, benefits the environment by reducing the source. More importantly, reductions are made in the shipping weight and savings in the cost of materials through the minimum container. Because it is constructed of pre-cut strips instead of die-cut pieces, there is no waste associated with the minimum container. Also, because the overlapping joints of the pre-cut strips occur at the corners of the minimum container, their corners have increased resistance to sustain the stacking of containers. In a preferred aspect of the minimum container, a minimum container for shipping disposable consumer items comprises a rectangular corrugated cardboard frame having four sides, an upper end and a lower end. Each of the four sides, the upper ends, and the lower end has an open area. The rectangular frame is made of interlocking strips held together so that no cardboard waste is generated. A thin film is wrapped around and encloses the four sides, the upper ends, and the lower end of the rectangular frame after the contents have been placed inside it. The flexible film envelope is connected to the rectangular frame in such a way that the frame is stiffened and the contents are protected. Preferably, the interfitting strips have contact fastening face to face in such a way that when they are held together, the interfitting strips form a substantially flat ladder structure having two ends. The staircase structure is pre-marked and cut into strips to facilitate the folding of the same. The rectangular frame is formed by folding the substantially staircase-like structure from one end to the other, and then jointly holding the two ends of the structure in the form of a staircase. The flexible film is preferably either shrink wrapped around the rectangular frame such that the connection to the rectangular frame is via friction, or, the flexible film is wrapped around the rectangular frame and intermittently heat bonded thereto. In another preferred aspect of the minimum container, a ladder-shaped structure to form a minimum container, a height, and four side corners. The staircase structure comprises two longitudinally corrugated cardboard strips, placed substantially parallel to each other, and four lateral corrugated cardboard strips having outer ends and central lines along the length. The two longitudinal strips have external edges and lengths of at least as large as the minimum container perimeter. The two longitudinal strips are placed such that the end edges are spaced apart at a distance of at least as large as the height of the minimum container. The four side strips have lengths of at least as short as the minimum container height. The four side strips are placed substantially perpendicular to the two longitudinal strips with the outer ends being placed between the outermost edges of the longitudinal strips. The four side strips are separated apart to form a stair-shaped structure. The center lines longitudinally of the four side strips correspond to the four lateral corners of the minimum container when the staircase-like structure is folded along the center lines. The four side strips are attached to the two longitudinal strips wherever overlap occurs between them. Preferably, the four side strips are marked to fold them along the center lines longitudinally.

More preferably, the ladder-shaped structure includes an upper longitudinal strip having a first end edge and a lower longitudinal strip having a second end edge, where the first and second end edges are spaced apart at a distance greater than the length of each of the four side strips. Each of the four side strips have first and second outer ends, and the first outer ends are positioned along the first end edge of the top strip. The longitudinal bottom strip is split into strips, from the second end edge towards the second outer ends of the four side strips, in line, with the center lines longitudinally of the four side strips. When the ladder-shaped structure is folded longitudinally in the center lines, the lower longitudinal strip has a portion extending below the second outer ends that are bent at approximately 90 °, perpendicular to the four side strips to form lower lashes of the minimum container. The lower tabs have a flap near the four side corners of the minimum container and are held together in the flap. In yet another preferred aspect of the minimum container, a method of constructing a minimum container for shipping disposable articles to the consumer comprises the steps of pre-cutting cardboard and corrugated strips and arranging them with overlapping surfaces face to face; fastening the corrugated cardboard strips together on the overlapping surfaces to form a stair-shaped structure having two ends; mark the stair structure by bending; folding the stair-shaped structure and holding the structure together at the two ends to form a rectangular frame; place the content to be shipped in the rectangular frame; wrap and enclose the rectangular frame with a flexible plastic film; and connect the flexible plastic film to the rectangular frame in such a way as to stiffen the rectangular frame and protect the contents. Preferably, the corrugated cardboard strips are held together either by hot melt adhesive or by staples.

BRIEF DESCRIPTION OF THE DRAWINGS Although the specification concludes with the claims that particularly state and distinctly claim the subject matter that is considered to form the present invention, it is believed that the invention will be better understood from the following description, which is taken in conjunction with the accompanying drawings , in which like designations are used to designate substantially identical elements, and in which: Figure 1 is a perspective view of a preferred embodiment of the minimum container of the present invention describing the construction of the rectangular frame wrapped with a plastic film flexible; Figure 2 is a top plan view thereof, but without the film wrap showing the manner in which the lower side corrugated members are connected; and Figure 3 is a front elevation view of a minimum container before it has been formed in a rectangular frame, describing the staircase structure of the interconnected corrugated cardboard strips.

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, and more particularly to Figure 1, there is shown a first preferred embodiment of a minimum container, which is generally indicated as 10. The minimum container 10 is a dimensional rack having an upper strip 12, a lower strip 14, corner strips 16, and a transparent plastic film wrap 18. The container 10 is preferably rectangular with four sides 20 and an upper end 22, and a lower end 24. All sides and top and lower preferably have large open areas to minimize the weight of the container. The plastic film 18 is wrapped externally around the four sides 20, the upper end 22, and the lower end 24, and connected to the corner strips 16 to improve the stiffness of the container 10 as well as to protect the contents of the container. Alternatively, the container 10 may have less or more corners and be different from the rectangular shape. Additional strips can be added as needed. However, all the strips are pre-cut preferably such that no waste is generated in the formation of the minimum container 10. The upper strip 12 and the upper strip 14 are longitudinal strips extending around the perimeter of the container 10, and are made of preference for corrugated cardboard with corrugations running perpendicular to the length of the strips. The upper and lower strips 12 and 14 each have ends which preferably abut in the same corner, such as in a corner 26. The corner strips 16 are preferably folded side strips which overlap the upper and lower strips 12 and 14 and are attached to the longitudinal strips by adhesive, staples, or other common means for securing surfaces face to face, flat, together. The corner strips 16 are preferably made of corrugated cardboard whose corrugations run parallel to their lengths. Therefore, the corrugations of all the pieces of preference run vertically in the container 10, as shown in Figure 1, in order to maximize the resistance of the container 10 to the stacking loads placed against the upper ends 22. The strips at corner 16 are preferably strips of equal width bent at angles around axes longitudinally at their centers. The corner strips 16 are preferably placed outside the upper and lower strips 12 and 14 in such a way that the connections of the upper and lower parts 12 and 14 at the corners 26 are made inside the corner strips. The connections made inside the corners do not detract from the external appearance of the container 10, and the external corner strips do not reduce the internal volume of the upper and lower corner, which preferably encloses the contents of the container closely. Figures 1 and 2 show the lower strip 14 having a flange 28 bent inward, said flange being preferred because it significantly increases the structural rigidity of the container 10. The ends of the flange 28 overlap and are held together. The upper strip 12 can also have said flange, but none is shown in Figure 1. The plastic film 18 improves the stiffness of the container 10 when it is connected to the cardboard strips. Preferably, the connection is by hot sealing of points, such as corner strips 16 at points 30. However, a film wrapped by shrink or the like may have sufficient connection due only to friction. Staples can also be used. The minimum container 10 can be formed by holding the pre-cut strips together in a three-dimensional frame; however, it is preferably constructed from a substantially planar structure which can either be bent, clamped and then loaded with the contents; or that can be folded around the contents and then held together. Figure 2 shows an open container of the upper ends that is formed before loading the contents. Figure 3 shows a substantially flat assembly of two pre-cut longitudinal strips 12 and 14, and four pre-cut side strips 16, all clamped together, where they overlap to form a stair-shaped structure 40. The ladder-like structure 40 can be folded around the contents of the container and then fastened and can be folded to form the empty container of Figure 2. The stair-shaped structure 40 of Figure 3 has a lower strip 14 with flange 28. The upper strip 12 has no eyelash. The longitudinal strips 12 and 14 have end edges 42 and 44, respectively. The side strips 16 have external ends 46 and 48 and center lines 50 longitudinally. The side strips 16 are placed against the longitudinal strips 12 and 14 with their outer ends 46 substantially level with a central line 52 running the length of the lower strip 14. The flange 28 extends beyond the outer ends 46 on the another side of the center line 52. Within the flange 28 slits 54 are cut from the outer edge 44 towards the center line 52 to allow the flange 28 to be bent perpendicular to the strips 12 and 14 when the structure in the form of staircase 40 in a three-dimensional rectangular expander. The slits 54 are perpendicular to the end edge 44 and these are located along the center lines 50. In order to more easily bend the staircase structure 40 into a three-dimensional rectangular expander the stair-shaped structure 40 is marked with preferably along the center lines 50 such that the center lines 50 reach the corners of the container 10. When the stair-shaped structure 40 is bent, the height of the container 10 is preferably defined by the length of the side strips 16, and the length and width of the container 10 are defined by the spacing between the center lines 50. The lengths of the longitudinal strips 12 and 14 are such that they completely meet the internal perimeter of the container 10, as shown in Figure 1. The stair-shaped structure 40 has two opposite ends 60 and 62, the end 60 having longitudinal strips 12 and 14, overlapped by only half of the strip lateral 16. The remainder of the side strip 16 extends beyond the ends of the strips 12 and 14. The end 62 only has the opposite ends of the longitudinal strips 12 and 14. When the container 10 is bent, the end 62 it can be attached to the limit of the half of the side strip 16 to form a complete rectangle with the ends of the longitudinal strips 12 and 14 bordering. Alternatively, the strips 12 and 14 may be slightly shorter than the entire internal perimeter of the container 10. In this case, the bracket will be completely closed. However, the side strip 16 can still be fastened to the ends of the strips 12 and 14 to maintain the container 10. If the strips 12 and 14 are longer than the internal perimeter of the container 10, there would have to be some overlap of the strips 12 and 14. This is undesirable because said overlap can prevent the strips 12 and 14 from wrapping tightly against the contents of the container 10. In a particularly preferred embodiment of the present invention, a minimum container has dimensions of 393.7 mm. width 514.3 mm in length, and 247.6 mm in height, and made of 275 pounds of Kraft corrugated cardboard strips. All the strips are approximately 101.6 mm wide, except for the upper strip 12 which is 76.2 mm wide. The cardboard is available from Container Corp. of America of Cincinnati, OH. The pre-cut strips are glued together wherever they overlap in the stair-shaped structure, and the lower flange 28 when formed in the three-dimensional rectangular frame. The glue is preferably a standard hot melt adhesive used to seal boxes, which is applied manually by a hot melt adhesive gun, such as a 3M Polygun TC hot melt applicator, made by 3M Corp of St. Paul, MN Alternatively, an automated means for making cardboard pieces of the ladder structure 40 may be available using a gluing-bending-grooving machine, such as model no. ZLM, made by The ard Company of Cockeysville, MD. Said machine would also groove and mark the structure in the form of a staircase while it is still in its flat form. The ladder-shaped structure is preferably wrapped around the contents, such as Pampers®, made by The Procter & amp;; Gamble Company of Cincinnati, Ohio. This can be done by a surrounding wrapping box packaging machine made by The Douglas Co. of Alexandria, MN. This machine also seals the ends 60 and 62 together and bends and seals the overlapping tabs 28 to complete the cardboard structure of the minimum container 10. Once the minimum container is formed, filled and fastened, it is wrapped with a plastic film of two. thousandths of an inch thick, for example the polyethylene film, made by Bermis Co. of Terre Haute, IN. This movie is a bit transparent. An automated means for wrapping the plastic film 18 around the three-dimensional frame is a Hayssen multiple flow machine, Model no. HC-40, made by Hayssen Co. of Sheboygan, WI. The wrapping of the plastic film 18 is finally heat-sealed by stitches to the corner strips of the cardboard 16 at points 30, using a hot die or hot melt adhesive, which melts through the film and joins the edges of the film. hole of the resulting film to the cardboard. Seals are desired for points because the minimum container herein is believed to gain a substantial increase in stiffness to double compared to one sealed by points. It is believed that the preferred minimum container closely provides the same stacking strength as a regular slotted container. The double wall corners compensate for the absence of solid side walls. However, the preferred minimum container only weighs about half the weight of the same size as the Regular Slotted Container. Although a particular embodiment of the present invention has been illustrated and described, it would be obvious to those skilled in the art that other changes and modifications may be made without departing from the scope and the scope of the present invention. Accordingly, it is intended to cover all these changes and modifications in the appended claims.

Claims (10)

1. A minimum container for shipping disposable articles to the consumer, said minimum container characterized by: a) a rectangular corrugated cardboard frame having four lateral sides, an upper end and a lower end, each of said four sides, said upper end and said lower end having an open area, said rectangular frame being made of interlocking strips held together such that no cardboard waste has been generated; and b) a flexible film wrapped around and enclosing said four sides, said upper end, and said lower end of the rectangular frame after the contents have been placed in said rectangular frame, said flexible film envelope connected to said rectangular frame of such that said rectangular frame is stiffened and said contents are protected.

2. - A structure in the form of a ladder to form a minimum container having a perimeter, a height, and four lateral corners, said structure in the form of a staircase characterized by: a) two strips of longitudinal corrugated cardboard placed substantially parallel to each other, said two longitudinal strips having end edges and lengths of at least as large as said perimeter of said minimum container, said two longitudinal strips placed such that said end edges are spaced apart at a distance of at least as great as said height of said minimum container; and b) the four lateral corrugated strips extending outer ends and longitudinal center lines, said four lateral strips having lengths at least as short as said height of said minimum container, said four lateral strips being placed substantially perpendicular to said two longitudinal strips with said external ends placed between said end edges of said longitudinal strips, said four side strips being spaced apart to form a ladder-shaped structure, such that said center lines of said four side strips correspond to said four lateral corners of said minimum container when said ladder-shaped structure is bent in said center lines longitudinally, said four lateral strips being fastened to said two longitudinal strips wherever the overlap occurs between them.

3. The minimum container according to claim 1 or claim 2, further characterized in that said flexible film is shrink wrapped around said rectangular frame in such a way that said connection to said rectangular frame is via friction.

4. The minimum container according to claim 1 or claim 2, further characterized in that said flexible film is wrapped around said rectangular frame and intermittently heat bonded thereto.

5. - The staircase structure according to any of claims 2 to 4, further characterized in that said four side strips are marked to fold along said center lines longitudinally.

6. - The ladder-shaped structure according to any of claims 2 to 5, further characterized in that said two longitudinal strips include an upper strip having a first end edge and a lower strip having a second end edge, said first and second end edges being spaced apart at a greater distance than said length from each of said four side strips, each of said four side strips having first and second outer ends, said first outer ends being positioned at said first end edge of said upper strip, said lower strip being grooved from said second end edge towards said second external ends of said four lateral strips in line with said center lines longitudinally of said four side strips, such that when the ladder-like structure is folded into said center lines longitudinally, said lower strip has a portion extending below said second external ends that is bent at approximately 90 ° perpendicular to said four lateral strips for forming the lower tabs of said minimum container.

7. The staircase structure according to claim 6, further characterized in that said lower flanges have an overlap near said four lateral corners of said minimum container and are held together in said overlap.

8. - A method to build a minimum container for shipping disposable items to the consumer, said method characterized by the steps of: a) pre-cutting strips of corrugated cardboard and arranging them with overlapping surfaces face to face; b) fastening said corrugated cardboard strips together in said overlapping surfaces to form a stair-shaped structure having two ends; c) marking said structure in the form of a ladder to bend; and d) folding said structure into a ladder and holding said structure together at said two ends to form a rectangular frame.

9. The method according to claim 8, further characterized by the steps of: e) placing the contents that will be shipped in said rectangular frame; f) wrapping and enclosing said rectangular frame with a flexible plastic film; g) connecting said flexible plastic film to said rectangular frame in such a way as to stiffen the rectangular frame and protect said contents.

10. The method according to claim 8 and claim 9, further characterized in that said corrugated cardboard strips are held together by a hot melt adhesive.