Methods for creating multi-walled containers and articles produced there from

Abstract

Methods for making multi-walled containers from a single blank, preferably using a continuous process approach, and the resulting containers are disclosed. Various embodiments of the invention include, alone or in combination, intermediate panels formed from flap precursors that are in- or out-folded such that their distal ends are in proximate relationship to each other; outer flaps sized to overlap exposed edges of a container formed from the blank; stress relief features a joint corners to reduce stresses thereat. Methods for making select containers of the invention include folding and adhering the flap precursors to an inner panel, up-folding the inner panel / intermediate panel combination about a mandrel, and continuing to up-fold the outer panel until a container having a “use” position as a resting position is formed.

Description

BACKGROUND OF THE INVENTION[0001]Large format containers, generally referred to as “bins”, are used to hold a variety of materials, usually for transport but also for retail display. Because more than 95% of all products in the US are shipped in corrugated boxes, and because of the cost advantages associated with this form of packaging, most bins are constructed from corrugated paperboard. But while about 90% of all corrugated paperboard is single wall, the relatively large dimensions of bins in conjunction with the nature of the goods being placed in the bins require the additional strength provided by multiple wall construction.[0002]The prior art is replete with various methods for establishing a desired level of sidewall burst strength, bottom crush resistance and vertical load capacity for bins. Some solutions employ the use of double or triple wall corrugated paperboard as the starting material, while others rely upon layering walls or nesting boxes. Each of these approaches, ...

AI Technical Summary

Benefits of technology

[0004]Embodiments of the invention in one respect are directed to methods for creating a multi-walled container (and resulting articles) from a corrugated material with minimal intentional waste, wherein the container is formed from a single sheet or preferably a continuous web of corrugated material, such as single wall corrugated board, or double wall corrugated board. Because embodiments of the invention create a multi-walled container from a single sheet or web of material (as opposed to using inserts or a box-within-a-box design), it is possible, as well as desirable, to create the container in a single operation, which advantageously lends itself to a continuous process. Moreover, a continuous process will usually dispense with the need to manage container blanks. Additionally, multi-walled containers are usually large, e.g., from approximately 40″ in width / side. At this scale, conventional container blanks would be very large, approaching 30 feet in length. If embodiments of the invention were formed using traditional construction methodologies, e.g., one apparatus manufactures the blanks, the blanks are then moved to storage, and then moved to a box making machine, storage, transport and handling of such large format blanks would present a formidable challenge. By using a continuous process wherein a web or constant source of material is fed into a box making machine, all material handling requirements that would otherwise be associated with conventional blank-based box making procedures can be eliminated.

[0007]Embodiments of the invention in yet another respect are directed to methods for creating a multi-walled container (and resulting articles) that has a generally unstressed vertical fold at all corner edges. By forming the container about a mandrel having the desired shape of the container (at least side walls thereof, the resultant container's relaxed state is that of its in-use form. As a result, each vertical corner of a four-sided container is less susceptible to tearing and breakage during use, as is common in the prior art. The same applies to both 6 and 8 corner styles. Moreover, handling and storage of the resulting containers is enhanced since no vertical corner in the four sided configuration, for example, undergoes substantially greater than a 90° bend from its “use” geometry to its “knocked down” geometry.

[0012]In certain embodiments, an interlocking or inter-meshing pair of middle flap edges is established. In these embodiments, stresses at what would otherwise be localized at a butt joint after involution and formation of the container are dispersed over a larger area of the container when in use. This is especially important when maximizing burst and vertical compression strength values.

[0013]Still other embodiments of the invention employ a corner stress relief feature at the intersection of a flap joint and a panel joint, preferably on the outermost panels and flaps. Because this intersection would otherwise undergo bidirectional manipulation, select removal of material from this intersection permits a greater degree of articulation and delocalizes stresses that would otherwise occur at a single, small location.

[0014]And yet other embodiments of the invention provide for the slit separating two flaps to be off set from a score to facilitate bending of two adjacent panels. The offset, which preferably occurs with respect to the outer panels and flaps, is preferably approximately equal to the thickness dimension of the material used to construct the container. When implemented, each flap will have a width dimension that is different (longer or shorter) than the width dimension of the panel width from which it extends. When the container is assembled into its final configuration, the wider outer flaps will extend to the outer edge of the container, and the inner flaps will fully extend over the intermediate and inner layer, thereby providing additional stacking strength and making full use of, and contact with, the outer panel(s) of the container. Those persons skilled in the art will appreciate that this configuration is more easily achieved when used in conjunction with the previously described stress relief feature.

Problems solved by technology

If embodiments of the invention were formed using traditional construction methodologies, e.g., one apparatus manufactures the blanks, the blanks are then moved to storage, and then moved to a box making machine, storage, transport and handling of such large format blanks would present a formidable challenge.

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