Carton with folded-in gusset tips

A package having a bottom wall with in-folded gusset tips includes a plurality of upstanding side walls, each side wall contiguous or sealed to its adjacent side walls, a sealed top and a sealed bottom wall. The sealed bottom wall is formed from opposing leading and trailing panels, intermediate, opposing gusset panels and a sixth panel. The gusset panels are folded inwardly toward one another to form triangular panels. The triangular panels are disposed interior of the leading and trailing panels. The ends of the gusset panels define triangular tips that are folded away from one another. The sixth panel has a length that is less than or equal to the distance between the gusset tips.

BACKGROUND OF THE INVENTION

The present invention pertains to a carton having a folded and sealed bottom wall. More particularly, the present invention pertains to a carton having a bottom wall having folded-in gusset tips.

One common form of container for milk, juice and the like is the gable top carton. Recently, packaging technology has made enormous strides vis-à-vis these gable top cartons, as well as other types of packages. At present, technology permits packaging perishable food items for non-refrigerated extended shelf lives. These packages provide the ability to bring these food items into parts of the world that have limited transportation, distribution and storage infrastructure.

In view of this, efforts have been made to increase the high standards of cleanliness in the formed, filled and sealed containers to provide the highest quality product and to provide the greatest product shelf life. And, in conjunction with this, the demands on the overall packaging processes have been maintained vis-à-vis machine operating speeds. Such machines must form, fill and seal packages, in a sterile environment, at high operating speeds.

In order to maintain the integrity of the package after it is filled and sealed, advanced technologies have been applied to the carton materials, as well as the processing operations. Many such packaging materials are formed from paperboard or fiberboard-based materials formed in a composite structure. Typically, one or more layers, such as polymeric coatings, foil coatings and the like, are applied to the paperboard or fiberboard substrate to reduce or eliminate the gas and liquid permeability of the substrate material.

It has been found that one avenue for providing an environment that reduces the shelf life is wicking of the food product into the package material. Wicking occurs at the edges of the material that are exposed to the food product. Typically, wicking occurs at the raw or exposed edges of the bottom wall panels as they are folded to form the bottom wall. To this end, it has been found desirable to reduce the amount or extent of exposed edges, and in particular at the bottom wall. It has also been found that the foil at the tips of the gussets (the in-folded triangular panels) can crack thus exposing the paperboard substrate material.

One package that has affected a reduction in wicking is disclosed in U.S. Pat. No. 6,328,204 to Stacy-Ryan and an apparatus to form such an over-folded bottom is disclosed in U.S. Pat. No. 6,385,950 to Anderson, both of which patents are commonly assigned with the present application and are incorporated herein by reference. While this over-folded bottom served to “cover” the exposed edges from the bottom front or rear panel, the increase in material required was undesirable.

Accordingly, there exists a need for a carton bottom folding configuration that reduces or eliminates the raw (exposed) paper edges within the carton product storage region. Desirably, such a carton uses, for the most part, a traditional creasing, folding and sealing configuration. Most desirably, such a carton can be formed on known form, fill and seal packaging machines (with minimal modification) and using less packaging material than known over-folded bottom arrangements.

BRIEF SUMMARY OF THE INVENTION

A package having a bottom wall with in-folded gusset tips includes a plurality of, preferably four, upstanding side walls, each side wall contiguous or sealed to its adjacent side walls. The package has a sealed top, such as the familiar gable top, and a sealed bottom wall. The sealed bottom wall is formed from opposing leading and trailing panels and intermediate, opposing gusset panels. The gusset panels are folded inwardly toward one another to form triangular panels. The triangular panels are disposed interior of the leading and trailing panels. The ends of the gusset panels define triangular tips that are folded away from one another.

In a present package, the triangular tips are disposed between the triangular gusset panels and the leading and trailing panels, and the leading panel is sealed over the trailing panel. The triangular tips are spaced a predetermined distance from one another.

A sixth panel is contiguous with the trailing panel. The sixth panel is folded rearwardly so as to lie between the leading and trailing panels. The sixth panel has a length that is less than the distance between the triangular panel tips. A blank for forming the package is also disclosed.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the package10in accordance with the principles of the present invention is illustrated inFIG. 1. The package10can include an optional closure, such as a threaded cap or flip-type cap (not shown). The package10appears to be a conventional package having a gable top12, first and second side walls14,16, a front wall18, a rear wall20, front and rear top panels22,24, top infolded or side gable panels26,28and a top fin30. The bottom wall32, likewise appears as a conventional bottom wall. A longitudinal side seal wall34(or fifth panel, shown in blank form inFIG. 8) is formed adjacent one of the side walls16for sealing to, for example the front wall18, to form the tubular carton form.

The bottom wall32is formed from in-folded side gusset panels36,38and front and rear or leading and trailing panels40,42. As seen inFIG. 2, as viewed from the inside of the carton10, the tips44,46of the infolded triangular or gusset panels36,38are folded over or folded in, so that they lie under the triangular panels. That is, the tips44,46are folded over so that they lie between the triangular panels36,38and the leading and trailing bottom panels40,42. As seen from the inside of the package10, the gusset panels36,38appear to have a truncated triangular shape, thus defining a folded over edge (indicated at48,50), rather than leaving a raw or uncoated edge portion within the inside (product storage region) of the carton10. In this arrangement, when the bottom panels36–42are heated and sealed, the tips44,46lie within a sealed region and as such are isolated from the product storage region (or wetted region if used for liquid food packaging) of the carton10. Those skilled in the art will recognize that the polymer coating on the paperboard softens and melts during the sealing process thus fusing the panels (coatings) to one another.

A tab or sixth panel52is folded over so that the raw or uncoated edge of the trailing panel42is also outside of the product storage or wetted region. That is, the uncoated edge is “shifted” from the end of the trailing panel42to the end of the tab panel52and, because the tab panel is folded over, the uncoated edge (indicated at54) is thus, like the gusset tips44,46, sealed between the triangular panels36,38and the bottom panels40,42. In a present package, the sixth panel52has a width (as at w52) and a length (as at l52). This configuration results in less material (about 3 percent less than known configurations) which provides a material cost savings.

A blank110for the package10is shown inFIG. 8. The blank110has a plurality of panels that correspond to the front wall18, the rear wall20and the side walls14,16. The panels14–20are partitioned from one another by a plurality of vertical score or crease lines112. Those skilled in the art will recognize that the score or crease lines are those areas in the packaging material that facilitate folding the material along a predetermined, desired line. The lines are formed by, for example, embossing and the like. For purposes of the present disclosure, the terms score line and crease line are to be considered interchangeable.

A plurality of corresponding bottom panels32–38are partitioned from the corresponding or respective front, rear and side panels14–20by a lower horizontal score line114. A plurality of lower diagonal score lines116further define the bottom gusset panels36,38and are for folding purposes. The bottom or tab panel52(also referred to as the sixth panel) is separated from the trailing panel42by a score line118.

In known carton blanks, the diagonal score lines extend fully from the horizontal score line separating the side panels from the bottom panels to the edge of the bottom panels (indicated at120), and the score lines meet at the edge to form the triangular panels.

In the present blank110, the diagonal score lines116(referred to herein as major diagonal score lines) terminate at a folding region122that includes a rectangular area124having smaller triangular areas126adjacent to the sides of the rectangular area124. The areas124,126are defined by a first horizontal score line128contiguous with a pair of spaced apart vertical score lines130(forming an upside-down U). The major diagonal score lines116terminate at the corners132of the U or at the respective junctures of the horizontal and vertical score lines128,130.

To accommodate the in-folding of the tips,44,46each of the bottom gusset panels36,38includes a pair of minor diagonal score lines134that extend from the edge120of the panel to the respective junctures (corners)132of the horizontal and vertical score lines128,130with the major diagonal score lines116.

FIGS. 3–6illustrate the carton bottom32as it is being folded. The bottom side (gusset) panels36,38are slightly infolded at the triangular portions36a,38a, of the panels36,38. In addition, the folding regions122are folded or pulled outwardly (see arrow A inFIG. 3) relative to the in-folding of the triangular portions36a,38aof the panels36,38. This forms the truncation of the gusset panels36,38by folding the tips44,46of the panels36,38.

FIG. 7illustrates the bottom32(exterior) of the carton with portions of the leading and trailing bottom panels40,42cut away to better view the in-folded gusset tips44,46and the optimized sixth panel52. In these views, it can be seen that the sixth panel52is folded into the folds of the44,46. To this end, the sixth panel52has a length l52(at the base of the panel52, at score line118) that is slightly less than the distance d44-46between the triangular tips of panels44,46(seeFIG. 7). In addition, the angle α (formed by the folding of the tips44,46(formed by or along crease lines134) is less than or preferably about equal to the angle β formed by the edge52aof panel52. In this manner, the panel52lies wholly within a “footprint” that is defined by the folded tips44,46, and the leading and trailing bottom panels40,42. Accordingly, this configuration prevents an excessive number of “layers” of material. It has been found that this configuration provides the necessary area for proper sealing, while minimizing the amount of material needed.

Referring now toFIGS. 1 and 8, the top or gable portion12of the carton10is formed as in a traditional manner. The front panel22is partitioned from the front wall18by an upper horizontal score line136. Likewise, side top panels26,28are partitioned by the score line136from their respective side wall panels14,16. The rear wall panel20corresponds to top panel24which is likewise partitioned therefrom by the upper horizontal score line136. The top fin30of the package10is formed by a plurality of fin panels, indicated generally at138inFIG. 8. The fin panels138are partitioned from their corresponding top panels by horizontal score lines. Those skilled in the art will recognize the configuration and folding/assembly of the top (gable)12and fin30.

All patents referred to herein, are hereby incorporated herein by reference, whether or not specifically done so within the text of this disclosure.