JP7550848B2 - Carton blanks and gable top cartons manufactured from carton blanks - Google Patents

Description

The present invention relates to carton blanks for producing paper or paperboard-based packages of the type commonly referred to as gable-top cartons. The present invention also relates to gable-top cartons produced from such blanks.

Gable top cartons are commonly used to distribute pourable bulk products and pourable products such as liquid consumables, e.g., dairy products such as milk and fruit juices. Gable top cartons are typically manufactured from laminated packaging materials, which include multiple sheets of paper or paperboard over which are laminated multiple barrier layers to retain liquids and/or prevent air and flavor-spoilers from migrating through the paperboard. The barrier layers may typically include layers of polyethylene or aluminum.

In manufacturing cartons, the laminated packaging material is cut to form roughly rectangular blanks, which are then folded, filled, and sealed to form the carton.

To facilitate folding of the carton blanks, the blanks have crease lines. As known in the art, crease lines are embossed or stamped depressions on one side of the paperboard that result in corresponding raised ridges or bulges on the other side, forming straight lines along which the paperboard is structurally weakened and along which the paperboard will bend or fold in a controlled manner when pressure is applied along the straight lines.

When placing crease lines on a cartonboard, attention must be paid to the corner locations, i.e., the locations on the blank that will form the corners of the carton when the blank is folded. In particular, special attention must be paid to how the crease lines approach and connect to the corner locations to obtain clearly defined corners. This is especially true for cartons that have more complex geometries than a strict rectangular block-like geometry.

The present invention addresses this problem by providing a carton blank having crease lines that have been found to provide clearly defined top corners, particularly the top corners on the front side of the carton.

In the following description, "longitudinal" is used to designate a direction substantially parallel to the side edges of the carton blank, and "transverse" is used to designate a direction substantially parallel to the top and bottom edges of the carton blank. "Diagonal" is used to designate a direction that is at a substantially 45° angle to the bottom, side and top edges.

According to a first exemplary aspect, the present invention relates to a carton blank having a plurality of panels configured to be folded to form a gable-top carton, each of the plurality of panels including a wall subpanel and a top closure subpanel, the carton blank including a vertical fold line defining an interface between two adjacent top closure subpanels, on which an upper corner location is disposed that is configured to form an upper corner of the carton when the carton blank is folded, the carton blank also including a horizontal fold line defining an interface between one of the adjacent top closure subpanels and an adjacent wall subpanel of the carton blank, the interface terminating at the upper corner location, the carton blank further including a diagonal fold line disposed on the one of the adjacent top closure subpanels, the diagonal fold line defining a fold line that terminates at the upper corner location.

In such carton blanks, it can be difficult to translate the top corner location into a clearly defined top corner in the folded carton, especially when the boundary defined by the horizontal crease lines forms an obtuse angle with the vertical crease lines when it terminates at the top corner location.

However, it has been found that by positioning the fold line defined by the diagonal fold lines so that when the fold line terminates at the upper corner location, it forms an angle of 70°, more preferably at least 80°, and even more preferably at least 90°, e.g. 90°, with respect to the vertical fold lines, a well-defined upper corner location can be obtained.

Thus, according to a first exemplary aspect, the present invention provides a carton blank including a plurality of panels configured to be folded to form a gable-top carton, each of the plurality of panels including a wall subpanel and a top closure subpanel.

The carton blank includes a vertical fold line that defines a boundary between two adjacent top closure subpanels, and upper corner locations are located on the vertical fold line that are configured to form upper corners of the carton when the carton blank is folded.

The carton blank also has a transverse fold line that forms a boundary between one of the adjacent top closure subpanels and an adjacent wall subpanel of the carton blank, the boundary terminating at an upper corner location.

The carton blank further includes an oblique crease disposed in the one of the adjacent top closure subpanels, the oblique crease defining a fold line that terminates at the top corner location.

When terminating at the upper corner location, the fold line forms an angle of at least 70° with the vertical crease line.

In alternative embodiments, the angle formed between the vertical crease line and the fold line defined by the diagonal crease line at the upper corner location may be at least 80° or at least 90°, for example 90°.

According to a second exemplary aspect, the present invention provides a carton blank configured to be folded to form a gable-top carton, the carton blank comprising:
the carton blank comprises first, second, third, fourth, and fifth panels;
Each panel is
a first subpanel configured to form a portion of a bottom closure of the carton;
a second subpanel adjacent to the first subpanel and configured to form a wall of the carton;
a third subpanel adjacent to the second subpanel and configured to form a portion of a top closure of the carton;
The carton blank comprises:
a first longitudinal fold line defining a boundary between the third sub-panel of the first panel and the third sub-panel of the second panel;
a second longitudinal fold line defining a boundary between the third sub-panel of the second panel and the third sub-panel of the third panel;
a third longitudinal fold line defining a boundary between the third sub-panel of the third panel and the third sub-panel of the fourth panel;
a fourth longitudinal fold line defining a boundary between the third sub-panel of the fourth panel and the third sub-panel of the fifth panel;
The second panel comprises:
a horizontal fold line defining a boundary between the second sub-panel and the third sub-panel of the second panel, the boundary extending across the second panel between a first top corner location on the first vertical fold line and a second top corner location on the second vertical fold line, the first top corner location configured to form a first top corner of the carton and the second top corner location configured to form a second top corner of the carton;
a first diagonal fold line of the second panel defining a fold line in the third sub-panel of the second panel terminating at the second upper corner location;
The fourth panel comprises:
a horizontal fold line defining a boundary between the second sub-panel and the third sub-panel of the fourth panel, the boundary extending across the fourth panel between a third top corner location on the third vertical fold line and a fourth top corner location on the fourth vertical fold line, the third top corner location configured to form a third top corner of the carton, and the fourth top corner location configured to form a fourth top corner of the carton;
a first diagonal fold line of the fourth panel defining a fold line in the third sub-panel of the fourth panel terminating at the third upper corner location;
the fold line defined by the first diagonal fold line of the second panel forms an angle of at least 70° with the second longitudinal fold line when terminating at the second upper corner location;
The fold line defined by the first diagonal fold line of the fourth panel forms an angle of at least 70° with the third longitudinal fold line as it terminates at the third upper corner location.

The angle formed between the first diagonal crease line and the second vertical crease line of the second panel and the angle formed between the first diagonal crease line and the third vertical crease line of the fourth panel may each be at least 80°, at least 90°, or at least 90°.

The angle formed between the first diagonal crease line and the second vertical crease line of the second panel may be equal to the angle formed between the first diagonal crease line and the third vertical crease line of the fourth panel.

The first diagonal crease of the second panel may include a diagonal crease portion having a convex portion toward the horizontal crease of the second panel, and the first diagonal crease of the fourth panel may include a diagonal crease portion having a convex portion toward the horizontal crease of the fourth panel.

The second panel may include a gable horizontal crease line that defines a boundary between the upper gusset sub-sub-panel and the gable closure sub-sub-panel of the third sub-panel of the second panel, and the fold line defined by the first diagonal crease line of the second panel may extend between the gable horizontal crease line of the second panel and the second upper corner position. The fourth panel may include a gable horizontal crease line that defines a boundary between the upper gusset sub-sub-panel and the gable closure sub-sub-panel of the third sub-panel of the fourth panel, and the fold line defined by the first diagonal crease line of the fourth panel may extend between the gable horizontal crease line of the fourth panel and the third upper corner position.

The boundary defined by the horizontal crease line of the second panel may form an obtuse angle with the second vertical crease line when it terminates at the second upper corner position, and the boundary defined by the horizontal crease line of the fourth panel may form an obtuse angle with the third vertical crease line when it terminates at the third upper corner position.

The horizontal crease line of the second panel may terminate at the second upper corner while presenting an arc having a first radius of curvature, the horizontal crease line of the fourth panel may terminate at the third upper corner while presenting an arc having the first radius of curvature, the first horizontal crease line of the second panel may terminate at the second upper corner while presenting an arc having a second radius of curvature, and the first horizontal crease line of the fourth panel may terminate at the third upper corner while presenting an arc having the second radius of curvature, the second radius of curvature may be smaller than the first radius of curvature.

The second radius of curvature may be 20% to 80% of the first radius of curvature, 40% to 60% of the first radius of curvature, or 45% to 55% of the first radius of curvature.

The arc of the first horizontal crease line of the second panel may have a center of curvature that is on the second vertical crease line, and the arc of the first horizontal crease line of the fourth panel may have a center of curvature that is on the third vertical crease line.

The arc of the horizontal crease line of the second panel may have a center of curvature that is located in the second panel at a lateral distance from the second vertical crease line, and the arc of the horizontal crease line of the fourth panel may have a center of curvature that is located in the fourth panel at a lateral distance from the third vertical crease line, and the lateral distance may be within a range of 40% to 90% of the first radius of curvature.

The second panel may include a second diagonal fold line defining a fold line in the third subpanel that terminates at the first upper corner and that forms an angle of at least 70° with the first vertical fold line, and the fourth panel may include a second diagonal fold line defining a fold line in the third subpanel that terminates at the fourth upper corner and that forms an angle of at least 70° with the fourth vertical fold line.

The second diagonal crease of the second panel may include a diagonal crease portion having a convex portion toward the horizontal crease of the second panel, and the second diagonal crease of the fourth panel may include a diagonal crease portion having a convex portion toward the horizontal crease of the fourth panel.

The angle formed between the second diagonal crease line and the first vertical crease line of the second panel may be the same as the angle formed between the second diagonal crease line and the fourth vertical crease line of the fourth panel.

According to a third exemplary aspect, the present invention provides a gable-top carton comprising the carton blank disclosed above.

The above preferred and/or optional features of each aspect may be used alone or in any suitable combination in other aspects of the present invention.

To facilitate understanding of the present invention, the following drawings are attached:

FIG. 1 is a plan view of one embodiment of a carton blank according to a first aspect of the present invention. FIG. 2 is a detailed view of the carton blank of FIG. 1. FIG. 2 is a detailed view of the carton blank of FIG. 1. FIG. 2 is a detailed view of the carton blank of FIG. 1. FIG. 2 is a detailed view of the carton blank of FIG. 1. FIG. 2 is a detailed view of a carton blank according to one embodiment of the present invention. FIG. 2 is a detailed view of a carton blank according to one embodiment of the present invention. FIG. 1 is a perspective view of a carton according to a first embodiment of the present invention. FIG. 7 is a side view of the carton of FIG. 6. FIG. 7 is a side view of the carton of FIG. 6. FIG. 2 is a plan view of a further embodiment of a carton blank according to the present invention. FIG. 2 is a plan view of a further embodiment of a carton blank according to the present invention. FIG. 2 is a plan view of a further embodiment of a carton blank according to the present invention. FIG. 2 is a detailed plan view of a further embodiment of a carton blank according to the present invention. FIG. 2 is a detailed plan view of a further embodiment of a carton blank according to the present invention. FIG. 13 is a detailed plan view of yet another embodiment of a carton blank according to the present invention. FIG. 13 is a detailed plan view of yet another embodiment of a carton blank according to the present invention.

Hereinafter, the embodiments of the present invention will be described in detail with reference to the drawings. However, the present invention is not limited to the embodiments and examples contained in this specification, and is intended to include modifications of the embodiments, including parts of the embodiments and combinations of elements of different embodiments, that fall within the scope of the following claims.

It will be appreciated that, for clarity, certain features of the invention described above in the context of separate embodiments may also be combined in a single embodiment. Conversely, for brevity, various features of the invention that are described in the context of a single embodiment may also be provided separately or in any suitable subcombination. In particular, it will be appreciated that features described in relation to one particular embodiment may be interchanged with features described in relation to other embodiments.

In the drawings, like reference numbers are used to indicate common parts, elements or features unless expressly stated or implicitly understood from the context.

An embodiment of a carton blank 10 of the present invention is shown in FIG. 1. Blank 10 is shown with a surface configured to form the outer surface of the carton that faces the viewer.

The blank 10 is made from a suitable packaging material, e.g., a multi-layer sheet of paper or paperboard, laminated with one or more barrier layers to retain contents, e.g., liquids, and/or prevent air or flavor-spoilers from migrating through the sheet. At least a portion of the blank may be coated with a layer of thermoplastic material that allows the carton formed from the blank to be sealed by plastic welding.

Blank 10 is substantially rectangular and includes a first edge, bottom edge 11, a second edge, top edge 12, and third and fourth parallel side edges, 13 and 14. Side edges 13 and 14 are straight, while top edge 11 and bottom edge 12 have irregular shapes. Blank 10 also includes a number of crease lines that define fold lines along which blank 10 is folded when formed into a carton.

In this description, "longitudinal" is used to designate a direction substantially parallel to side edges 13 and 14, i.e., substantially vertical in FIG. 1, and "horizontal" is used to designate a direction substantially parallel to top edge 11 and bottom edge 12, i.e., substantially horizontal in FIG. 1. "Diagonal" is used to designate a direction at a substantially 45° angle to the bottom edges, side edges, and top edges 11-14.

The blank 10 has five panels P1-P5 separated by longitudinal crease lines 20, 21, 22, 23 that define fold lines extending across the panel 10 from the bottom edge 11 to the top edge 12. The longitudinal crease lines 20, 21, 22, 23 thereby divide the bottom edge 11 and the top edge 12 into subsections 11a, 11b, 11c, 11d, 11e and 12a, 12b, 12c, 12d, 12e, respectively.

Each panel P1-P5 has a first subpanel 110, 210, 310, 410, 510 forming a lower closure subpanel, a second subpanel 120, 220, 320, 420, 520 forming a wall subpanel, and a third subpanel 130, 230, 330, 430, 530 forming an upper closure subpanel. The lower closure subpanel 110, 210, 310, 410, 510 is configured to form a lower closure of the carton and the upper closure subpanel 130, 230, 330, 430, 530 is configured to form an upper closure of the carton. The wall subpanel 120 of the first panel P1 is configured to form the rear wall of the carton and the wall subpanel 320 of the third panel P3 is configured to form the front wall. The wall subpanels 220 and 420 of the second and fourth panels P2 and P4 are configured to form the side walls of the carton. The fifth panel P5 is configured to be affixed to the inner surface of the first panel P1 adjacent the side edge 13 when the carton is formed.

The blank 10 , when formed, reveals locations TC1, TC2, TC3, TC4, BC1, BC2, BC3 and BC4 which define the top and bottom corners of the carton (see Figures 6-8).

Each of the vertical creases 20, 21, 22, 23 has a first vertical crease line portion 20a, 21a, 22a, 23a extending between the lower edge 11 and the lower corner position BC1, BC2, BC3, BC4, respectively. Each of the vertical creases 20, 21, 22, 23 also has a second vertical crease line portion 20b, 21b, 22b, 23b extending between the lower corner position BC1, BC2, BC3, BC4 and the upper corner position TC1, TC2, TC3, TC4, respectively, and a third vertical crease line portion 20c, 21c, 22c, 23c extending between the upper corner position TC1, TC2, TC3, TC4 and the upper edge 12. In this embodiment, the longitudinal fold lines 20, 21, 22, 23 are continuous, i.e., uninterrupted, and extend vertically across the blank 10 between the bottom edge 11 and the top edge 12. However, in alternative embodiments, the longitudinal fold lines 20, 21, 22, 23 need not be continuous or linear, and/or the longitudinal fold line portions 20b, 21b, 22b, 23b may be positioned to accommodate corner panel portions between the wall sub-panels 120, 220, 320, 420, 520.

The first panel P1 has a lower crease line 140 extending from a position BC1 to a position on the side edge 13 at the same height as BC1. In other words, the lower crease line 140 extends across the panel P1 in a direction perpendicular to the side edge 13 and the vertical crease line 20. The lower crease line 140 forms a boundary between the lower closure subpanel 110 and the wall subpanel 120 of the panel. In addition, the first panel P1 has an upper crease line 150 extending from a position TC1 to a position on the side edge 13 at the same height as or substantially the same height as TC1. Thus, in this embodiment, the upper crease line 150 extends across the panel P1 in a direction substantially perpendicular to the side edge 13 and the vertical crease line 20, i.e., parallel to the lower crease line 140. However, in alternative embodiments, the upper crease line 150 need not be parallel to the lower crease line 140. The upper fold line 150 forms the boundary between the wall subpanel 120 and the upper closure subpanel 130.

The bottom closure subpanel 110 has a flap 111 which helps ensure a secure closure of the bottom of the carton. In the art of carton manufacturing, the function of such flaps is known per se, and the flap 111 will not be described further here.

The top closure subpanel 130 has an upper fin crease line 131 that extends across panel P1 parallel to the upper crease line 150, i.e., perpendicular to the side edge 13 and the longitudinal crease line 20. The upper fin crease line 131 defines a fold line that forms the boundary between the roof sub-subpanel 132 and the upper fin sub-subpanel 133 of the top closure subpanel 130. In this embodiment, the top edge subsection 12a is slightly convex to provide a curved, convex top fin in the carton folded from the blank 10. However, the top edge subsection 12a may be straight, concave, or any other shape.

Panel P1 has discard crease lines 160a and 160b extending across the bottom of wall sub-panel 120. As is known in the art, the discard crease lines are not utilized during filling when the carton is folded from blank 10, but are utilized by the user during disposal of the emptied carton. In particular, as is known in the art, the discard crease lines are configured to facilitate folding of the empty carton into a flat shape, thereby ensuring space-efficient disposal.

The second panel P2 includes a lower crease line 240 that extends across the panel P2 between positions BC1 and BC2. BC1 and BC2 are at the same height, i.e., are disposed along a line perpendicular to the longitudinal crease lines 20 and 21. The lower crease line 240 therefore extends across the panel P2 in a direction perpendicular to the longitudinal crease lines 20 and 21. The lower crease line 240 forms the boundary between the lower closure subpanel 210 and the wall subpanel 220.

The second panel P2 further has an upper horizontal crease line 250 that extends across the panel P2 between positions TC1 and TC2 and defines a fold line that forms the boundary between the wall subpanel 220 and the upper closure subpanel 230. The upper horizontal crease line 250 is curved rather than straight like the corresponding crease line 150 of panel P1. The upper horizontal crease line 250 begins at position TC1, extends at a substantially right angle from the vertical crease line 20, and then curves toward the bottom edge 11 of the carton blank. Approximately halfway between the vertical creases 20 and 21, the upper crease line 250 transitions from a downward bend to an upward bend, and terminates at position TC2 with a circular arc 250' having a radius of curvature R1 and having a convex portion toward the second subpanel 220. This arc 250' forms an obtuse angle α, i.e., an angle between 90° and 180°, with the vertical crease line portion 21c (see Figures 2a and 3a). As a result, the upper horizontal crease line 250 has a first section 250a facing the upper edge 12, i.e., having an upwardly convex portion, and a second section 250b facing the lower edge 11, i.e., having a downwardly convex portion, with the first section 250a connecting at a right angle to the vertical crease line 20 and the second section 250b connecting at an upward incline to the vertical crease line 21.

The bottom closure subpanel 210 has a first diagonal fold line 211 extending between location BC1 and a location adjacent to the bottom edge subsection l1b intermediate the longitudinal fold lines 20 and 21. The bottom closure subpanel 210 also includes a second diagonal fold line 212 extending between location BC2 and a location adjacent to the bottom edge subsection l1b intermediate the longitudinal fold lines 20 and 21, thereby interrupting the first diagonal fold line 211 at this location. The diagonal fold lines 211 and 212 form fold lines that aid in folding the bottom closure subpanel 210 when the bottom closure of the carton is formed.

The top closure subpanel 230 includes a gable transverse fold line 231 that extends across panel P2 and defines a fold line that forms a boundary between the top gusset sub-subpanel 232 and the gable closure sub-subpanel 233 of the top closure subpanel 230.

The upper gusset sub-subpanel 232 has a second diagonal fold line 234 extending between a location TC1 and a location on the gable transverse fold line 231 intermediate the longitudinal fold lines 20 and 21. The upper gusset sub-subpanel 232 also has a first diagonal fold line 235 extending between a location TC2 and a location on the gable transverse fold line 231 intermediate the longitudinal fold lines 20 and 21, interrupting the second diagonal fold line 234 at this location.

The second diagonal fold line 234 is straight, whereas the first diagonal fold line 235 is curved and consists of a first section 235a with a convex portion towards the longitudinal fold line 21c and a second section 235b with a concave portion towards the longitudinal fold line 21c. The first diagonal fold line 235 transitions from the first section 235a to the second section 235b adjacent to a position TC2 and terminates at a position TC2 with a convex portion towards the transverse fold line 250 and presents a circular arc 235' with a radius of curvature R2 (see Figures 2a and 3a).

The gable closure sub-subpanel 233 has a gable vertical crease line 236 that extends parallel to and equidistant from the vertical crease lines 20 and 21 between the gable horizontal crease line 231 and the top edge subsection 12b. In other words, the gable vertical crease line 236 extends perpendicularly from the position on the gable horizontal crease line 231 where the diagonal crease lines 234 and 235 interrupt each other.

The second panel P2, like the first panel P1, has disposal creases 260a-260e that are configured to be utilized by the user when discarding the carton when empty.

The third panel P3 has a lower crease line 340 extending across the panel P3 between positions BC2 and BC3. BC2 and BC3 are at the same height, i.e., are disposed along a line perpendicular to the longitudinal crease lines 21 and 22. The lower crease line 340 thereby extends across the panel P3 in a direction perpendicular to the longitudinal crease lines 21 and 22. The lower crease line 340 defines a fold line that forms a boundary between the lower closure subpanel 310 and the wall subpanel 320 of the panel P3. The third panel P3 does not have a crease line that defines a fold line that forms a boundary between the wall subpanel 320 and the upper closure subpanel 330. Thus, in the carton obtained by folding the blank 10, there is no clear boundary between the wall subpanel 320 and the upper closure subpanel 330. Instead, the wall subpanel 320 and the top closure subpanel 330 transition continuously into each other and meet at a boundary region.

The top closure subpanel 330 has an upper fin crease line 331 extending across panel P3 in a direction perpendicular to the longitudinal crease lines 21 and 22, i.e., parallel to the lower crease line 340. The upper fin crease line 331 defines a fold line forming the boundary between the roof subsubpanel 332 and the upper fin subsubpanel 333 of the top closure panel 330. The roof subsubpanel 332 is provided with a circular through opening 334 for receiving a spout fixture. Like panel P1, the top edge subsection 12c is slightly convex to provide a curved convex upper fin in the carton folded from the blank 10.

The fourth panel P4 is substantially a mirror image of the second panel P2 such that the fourth panel P4 has a lower crease line 440 extending across the panel P4 between locations BC3 and BC4. BC3 and BC4 are at the same height, i.e., located along a line perpendicular to the longitudinal crease lines 22 and 23. Thus, the lower crease line 440 extends across the panel P4 in a direction perpendicular to the longitudinal crease lines 22 and 23. The lower crease line 440 forms the boundary between the lower closure subpanel 410 and the wall subpanel 420.

The fourth panel P4 further has an upper horizontal crease line 450 that extends across the panel P4 between positions TC3 and TC4 and defines a fold line that forms the boundary between the wall sub-panel 420 and the upper closure sub-panel 430. The upper crease line 450 is curved in a manner similar to the upper crease line 250 of panel P2, such that, starting at position TC4, the upper crease line 450 first extends at a substantially right angle from the vertical crease line 23 and then curves towards the lower edge 11 of the carton blank. Approximately halfway between the vertical creases 22 and 23, the upper crease line 450 transitions from a downward bend to an upward bend, terminating at position TC3 with a circular arc 450' having a radius of curvature R1 and a convex portion towards the second sub-panel 420. This circular arc 450' forms an obtuse angle α with the vertical crease line portion 22c (see Figures 2b and 3b). As a result, the upper horizontal fold line 450 has a first section 450a with a convex portion toward the upper edge 12, i.e., an upward convex portion, and a second section 450b with a convex portion toward the lower edge 11, i.e., a downward convex portion, the first section 450a connecting perpendicularly to the vertical fold line 23, and the second section 450b connecting at an upward incline to the vertical fold line 22.

The bottom closure subpanel 410 includes a first diagonal fold line 411 extending between location BC3 and a location adjacent to bottom edge subsection 11d intermediate longitudinal fold lines 22 and 23. The bottom closure subpanel 410 also includes a second diagonal fold line 412 extending between location BC4 and a location adjacent to bottom edge subsection 11d intermediate longitudinal fold lines 22 and 23, interrupting the first diagonal fold line 411 at this location. The diagonal fold lines 411 and 412 form fold lines that aid in folding of the bottom closure subpanel 410 when the bottom closure of the carton is formed.

The top closure subpanel 430 has a gable transverse fold line 431 that extends across panel P4 and defines a fold line that forms the boundary between the top gusset sub-subpanel 432 and the gable closure sub-subpanel 433 of the top closure subpanel 430.

The upper gusset sub-subpanel 432 has a second diagonal fold line 434 extending between a location TC4 and a location on the gable horizontal fold line 431 intermediate the longitudinal fold lines 22 and 23. The upper gusset sub-subpanel 432 also has a first diagonal fold line 435 extending between a location TC3 and a location on the gable horizontal fold line 431 intermediate the longitudinal fold lines 22 and 23, interrupting the second diagonal fold line 434 at this location.

The second diagonal fold line 434 is straight, whereas the first diagonal fold line 435 is curved and has a first section 435a with a convex portion towards the longitudinal fold line 22c and a second section 435b with a concave portion towards the longitudinal fold line 22c. The first diagonal fold line 435 transitions from the first portion 435a into the second section 435b adjacent to a position TC3 where it terminates with a convex portion towards the transverse fold line 450 and presents a circular arc 435' with a radius of curvature R2 (see Figures 2b and 3b).

The gable closure sub-subpanel 433 has a gable vertical crease line 436 that extends parallel to and equidistant from the vertical crease lines 22 and 23 between the gable horizontal crease line 431 and the top edge subsection 12d. In other words, the gable vertical crease line 436 extends perpendicularly from the position on the gable horizontal crease line 431 where the diagonal crease lines 434 and 435 interrupt each other.

The fourth panel P4, like the second panel P2, has disposal creases 460a-460e that are configured to be utilized by a user when discarding the carton when empty.

In the fifth panel P5, two collinear lower crease lines 540a and 540b define a fold line extending across panel P5 that is collinear with the lower crease lines 140, 240, 340 and 440 in panels P1-P4 and forms the boundary between the lower closure subpanel 510 and the wall subpanel 520 of panel P5. Two collinear crease lines 550a and 550b also define a fold line that is approximately collinear with the upper crease line 150 of the first panel P1 and forms the boundary between the body subpanel 520 and the upper closure subpanel 530. Additionally, the two collinear upper fin crease lines 531a and 531b define a fold line that is generally collinear with the upper fin crease lines 131 and 331 of panels P1 and P3, which fold line forms the boundary between the roof sub-subpanel 532 and the upper fin sub-subpanel 533 of the upper closure subpanel 530.

In this embodiment, the boundary defined by the horizontal crease line 250 of the second panel P2 forms an obtuse angle α of approximately 140° with the second vertical crease line portion 21c when it terminates at the second upper corner position TC2. Also, the boundary defined by the horizontal crease line 450 of the fourth panel P4 forms an obtuse angle α of approximately 140° with the third vertical crease line portion 22c when it terminates at the third upper corner position TC3. The fold line defined by the first diagonal crease line 235 of the second panel P2 forms an angle β of approximately 90° with the second vertical crease line portion 21c when it terminates at the second upper corner position TC2. Similarly, the fold line defined by the first diagonal crease line 435 of the fourth panel P4 forms an angle β of approximately 90° with the third vertical crease line portion 22c when it terminates at the third upper corner position TC3. In alternative embodiments, the angle β formed between the first diagonal crease line 235 of the second panel P2 and the second vertical crease line 21c, and the angle β formed between the first diagonal crease line 435 of the fourth panel P4 and the third vertical crease line 22c, may be either at least 80° and at least 90°, such as in the embodiment shown in FIG. 1, and may be 90°.

It has been found that this diagonal crease line configuration allows for predictable and accurate folding of the carton blank in the areas surrounding the top corner locations TC2 and TC3.

As described above, the arc 250' of the horizontal crease line 250 of the second panel P2 and the arc 450' of the horizontal crease line 450 of the fourth panel P4 both have a radius of curvature R1 (see Figures 2a, 2b, 3a, and 3b). Also, the arc 235' of the diagonal crease line 235 of the second panel P2 and the arc 435' of the diagonal crease line 435 of the fourth panel P4 both have a radius of curvature R2. The radius of curvature R2 of the arcs 235' and 435' is smaller than the radius of curvature R1 of the arcs 250' and 450'.

The second radius of curvature R2 may be in the range of 20% to 80% of the first radius of curvature R1, for example in the range of 40% to 60% of the first radius of curvature R1, or in the range of 45% to 55% of the first radius of curvature R1. In one embodiment shown in Figures 4 and 5, R1 is 14 mm and R2 is 6 mm.

4 and 5, arc 235' may have a center of curvature that lies on longitudinal crease line 21c, and arc 435' may have a center of curvature that lies on longitudinal crease line 22c, whereby it can be seen that diagonal creases 235 and 435 connect at right angles to upper corner locations TC2 and TC3, respectively, resulting in a particularly precise folding of the carton blank.

The arc 250' may have a center of curvature located at a lateral distance D from the longitudinal crease line 21c in the second panel P2, and the arc 450' may have a center of curvature located at the same lateral distance D from the longitudinal crease line 22c in the fourth panel P4. The lateral distance D may be in the range of 40% to 90% of the first radius of curvature R1. In the embodiment shown in Figures 4 and 5, the centers of curvature of the arcs 250' and 450' are located at a lateral distance D of about 11 mm from the longitudinal crease lines 21c and 22c.

The method of forming a carton from the carton blank 10 described above is as follows. After the blank of FIG. 1 is produced, the fifth panel P5 is sealed to the inside wall of panel P1 to form a sleeve that is open at both ends. This sleeve is then bottom sealed by folding the first sub-panels 110, 210, 310, 410 and 510 inward and sealing them to produce an open-top, bottom-sealed carton. A spout device (see FIGS. 6 and 7) is lowered into the open top of the carton and introduced into the opening 334 from inside the carton until its flange abuts the inner surface of the sub-panel 330 around the opening 334, sealing the flange to the innermost layer of the sub-panel 330 around the opening. The still-open-top carton is then filled with the liquid to be packaged.

Subpanels 130, 230, 330, 430 and 530 are then folded and sealed together to provide a hermetic top closure for the carton.

FIGS. 6-8 show a carton 600 formed from the blank 10 shown in FIG. 1. The carton 600 has upper and lower corners TC1', TC2', TC3', TC4', BC1', BC2', BC3' and BC4' defined by corresponding upper and lower corner locations TC1, TC2, TC3, TC4, BC1, BC2, BC3 and BC4 of the blank 10 (see FIG. 1). The carton 600 has a generally rectangular or square cross-section between the upper corners TC1', TC2', TC3', TC4' and the lower corners BC1', BC2', BC3', BC4'.

The carton 600 has a bottom closure 602 formed from subpanels 110, 210, 310, 410 and 510. The carton 600 further has a rear wall 610 formed from subpanel 120 and a front wall 606 formed from subpanel 320. The carton 600 also has a first side wall 604 formed from subpanel 220 and a second side wall 608 formed from subpanel 420.

The carton 600 also has a top closure 612 formed from sub-panels 130, 230, 330, 430 and 530. The top closure 612 has a rear roof section 614 formed from the sub-subpanel 132 and a front roof section 616 formed from the sub-subpanel 332. The top closure 612 also has a first gable section 618 formed from the portion of the sub-subpanel 232 bounded by the fold lines 234 and 235 and a second gable section 620 formed from the portion of the sub-subpanel 432 bounded by the fold lines 434 and 435. The top closure 612 further has an upper fin 622 where the sub-panels 130, 230, 330, 430 and 530 are sealed together, and a spout 624 located at the through opening 334 in the sub-subpanel 332.

Since there is no fold line between sub-panels 320 and 330 of third panel P3 (see FIG. 1), front wall 606 continues with front roof 616 through curved transition region T. In such an embodiment, it is difficult to clearly define second and third top corners TC2' and TC3' because this would result in unwanted folding of the carton material along the fold lines. However, precise folding of the carton material can be achieved by designing each diagonal fold line 235 and 435 to have a convex portion toward horizontal fold lines 250 and 450 and to terminate at corner locations TC2 and TC3 at arcs 235' and 435' having a radius of curvature R2 greater than the radius of curvature R1 of horizontal fold lines 250 and 450 (see FIGS. 2 and 3). However, this design of diagonal fold lines 235 and 435 is equally suitable for cartons having a fold line separating front wall 606 and front roof 616. Thus, in an alternative embodiment, a transverse crease line may separate the front wall and front roof portions, for example as shown in FIG.

A further embodiment of a carton blank 30 according to the present invention is shown in FIG. 9. This carton blank 30 differs from the carton blank 10 of FIG. 1 only in that the third panel P3 of the blank 30 has a transverse crease line 350 that extends across panel P3 between positions TC2 and TC3 and defines a fold line that forms the boundary between the wall subpanel 320 and the top closure subpanel 330.

Yet another embodiment of a carton blank 40 according to the present invention is shown in FIG. 10. This carton blank 40 differs from the carton blank 10 of FIG. 1 in that the transverse crease lines 250 and 450 terminate at corner locations TC1 and TC4, respectively, in the same manner that the transverse crease lines 250 and 450 terminate at corner locations TC2 and TC3, respectively. The carton blank 40 also differs from the carton blank 10 of FIG. 1 in that the diagonal crease lines 234 and 434 terminate at upper corner locations TC1 and TC4, respectively, in the same manner that the diagonal crease lines 235 and 435 terminate at upper corner locations TC2 and TC3, respectively. As a result, the horizontal crease line 250 terminates at the upper corner position TC1 while presenting an arc 250" having a radius of curvature R1 and a convex portion toward the second sub-panel 220. Also, the diagonal crease line 234 terminates at the upper corner position TC1 while presenting an arc 234' having a convex portion toward the horizontal crease line 250 and a radius of curvature R2 larger than the radius of curvature R1 of the arc 250" (see also FIG. 2). Furthermore, the horizontal crease line 450 terminates at the upper corner position TC4 while presenting an arc 450" having a radius of curvature R1 and a convex portion toward the second sub-panel 420. Also, the diagonal crease line 434 terminates at the upper corner position TC4 while presenting an arc 434' having a convex portion toward the horizontal crease line 450 and a radius of curvature R2 larger than the radius of curvature R1 of the arc 450" (see also FIG. 3).

Yet another embodiment of a carton blank 50 according to the present invention is shown in FIG. 11. This carton blank 50 differs from the carton blank 40 of FIG. 10 in that the first panel P1 does not have a transverse fold line separating the wall sub-panel 120 and the top closure sub-panel 130. This results in a carton formed from the blank 50 having a rear wall that is continuous with the rear roof through a curved transition region, similar to the front wall 606 and front roof 616 of the carton 600 shown in FIGS. 6-8.

The aforementioned curved portions 235a, 435b, 250b, 450b of the diagonal crease lines 235 and 435 and the horizontal crease lines 250 and 450 (see Figs. 2a and 2b) do not necessarily extend all the way to the respective upper corner positions. Figs. 12a and 12b show such an embodiment of a carton blank, in which the diagonal crease lines 235 and 435 and the horizontal crease lines 250 and 450 have straight portions 235c, 435c, 250c, 450c, respectively, disposed between the curved portions 235b, 435b, 250b, 450b and the respective upper corner positions TC2 and TC3, which straight portions 235c, 435c, 250c, 450c connect to the respective upper corner positions TC2 and TC3.

Also, the diagonal creases 235 and 435 and the horizontal creases 250 and 450 do not necessarily have to extend all the way to their respective top corner locations. Figures 13a and 13b show such an embodiment of a carton blank, in which the diagonal creases 235 and 435 and the horizontal creases 250 and 450 terminate before reaching the respective top corner locations TC2 and TC3, but close enough, i.e. within 0-5 mm, to define fold lines that extend to the top corner locations. Although it is preferred to have the creases 235, 435, 250, 450 extend all the way to the top corner locations TC2 and TC3, accurate folding of the carton blank can still be provided even if the diagonal creases 235 and 435 and the horizontal creases 250 and 450 terminate, for example, 2 mm before the respective top corner locations TC2 and TC3.

Although the subject matter of the present invention, i.e., the diagonal crease design of the top closure subpanels of the second and fourth panels, has been described with reference to specific carton blank and carton embodiments, it will be understood that the present invention may be implemented in other types of carton blanks and cartons. For example, the diagonal crease design according to the present invention may be implemented in blanks and cartons having bottom closure configurations other than those shown in the exemplary embodiments, or in blanks and cartons having dispensing means other than the illustrated spout.

In the foregoing specification, various aspects of the invention have been described and discussed with reference to exemplary embodiments. For purposes of explanation, specific numbers, systems and configurations have been set forth to provide a thorough understanding of the closure device and its operation. However, this specification is not intended to be construed in a limiting sense. Various modifications and variations of the exemplary embodiments, as well as other embodiments of the closure device, as would be apparent to one skilled in the art to which the disclosed subject matter pertains, are within the scope of the invention as defined by the following claims.

Claims (14)

A carton blank (10, 30, 40, 50) configured to be folded to form a gable-top carton (600),
The carton blank (10, 30, 40, 50) has a first panel (P1), a second panel (P2), a third panel (P3), a fourth panel (P4) and a fifth panel (P5);
Each of the panels is
a first sub-panel (110, 210, 310, 410, 510) configured to form a portion of a bottom closure (602) of said carton (600);
a second sub-panel (120, 220, 320, 420, 520) adjacent to said first sub-panel (110, 210, 310, 410, 510) and configured to form a wall (604, 606, 608, 610) of said carton (600);
a third sub-panel (130, 230, 330, 430, 530) adjacent to the second sub-panel (120, 220, 320, 420, 520) and configured to form a portion of a top closure 612 of the carton (600);
The carton blanks (10, 30, 40, 50) are
a first vertical fold line portion (20c) defining a boundary between the third sub-panel (130) of the first panel (P1) and the third sub-panel (230) of the second panel;
a second vertical fold line portion (21c) defining a boundary between the third sub-panel (230) of the second panel (P2) and the third sub-panel (330) of the third panel (P3);
a third vertical fold line portion (22c) defining a boundary between the third sub-panel (330) of the third panel (P3) and the third sub-panel (430) of the fourth panel (P4);
a fourth vertical fold line portion (23c) defining a boundary between the third sub-panel (430) of the fourth panel (P4) and the third sub-panel (530) of the fifth panel ( P5 );
The second panel (P2) comprises:
a horizontal fold line (250) defining a boundary between the second sub-panel (220) and the third sub-panel (230) of the second panel (P2), the boundary extending across the second panel (P2) between a first top corner location (TC1) on the first vertical fold line portion (20c) and a second top corner location (TC2) on the second vertical fold line portion (21c), the first top corner location (TC1) configured to form a first top corner (TC1') of the carton and the second top corner location (TC2') of the carton;
a first diagonal fold line (235) of said second panel (P2) defining a fold line in said third sub-panel (230) of said second panel (P2) terminating at said second upper corner location (TC2);
The fourth panel (P4) comprises:
a horizontal fold line (450) defining a boundary between the second sub-panel (420) and the third sub-panel (430) of the fourth panel (P4), the boundary extending across the fourth panel (P4) between a third top corner location (TC3) on the third vertical fold line portion (22c) and a fourth top corner location (TC4) on the fourth vertical fold line portion (23c), the third top corner location (TC3) configured to form a third top corner (TC3') of the carton and the fourth top corner location (TC4) configured to form a fourth top corner (TC4') of the carton;
a first diagonal fold line (435) of said fourth panel (P4) defining a fold line in said third sub-panel (430) of said fourth panel (P4) terminating at said third top corner location (TC3);
the fold line defined by the first diagonal fold line (235) of the second panel (P2) forms an angle (β) of at least 70° with the second longitudinal fold line portion (21c) when terminating at the second upper corner location (TC2);
The carton blank (10, 30, 40, 50), wherein the fold line defined by the first diagonal fold line (435) of the fourth panel (P4) forms an angle (β) of at least 70° with the third vertical fold line portion (22c) when terminating at the third upper corner location (TC3). The carton blank (10, 30, 40, 50) according to claim 1, wherein each of the angles (β) formed between the first diagonal crease line (235) of the second panel (P2) and the second vertical crease line portion (21c) and the angles (β) formed between the first diagonal crease line (435) of the fourth panel (P4) and the third vertical crease line portion (22c) is at least 80°, at least 90°, and at least 90°. A carton blank (10, 30, 40, 50) according to any one of claims 1 and 2, wherein the angle (β) formed between the first oblique crease line (235) of the second panel (P2) and the second vertical crease line portion (21c) is equal to the angle (β) formed between the first oblique crease line (435) of the fourth panel (P4) and the third vertical crease line portion (22c). the first diagonal fold line (235) of the second panel (P2) has a diagonal fold line portion (235b) having a convex portion toward the transverse fold line (250) of the second panel (P2);
2. The carton blank (10, 30, 40, 50) of claim 1, wherein the first diagonal fold line (435) of the fourth panel (P4) has a diagonal fold portion (435b) having a convex portion toward the horizontal fold line (450) of the fourth panel (P4). the second panel (P2) includes a gable transverse fold line (231) that defines a boundary between a top gusset sub-sub-panel (232) and a gable closure sub-sub-panel (233) of the third sub-panel (230) of the second panel (P2);
the fold line defined by the first diagonal crease line (235) of the second panel (P2) extends between the gable transverse crease line (231) of the second panel (P2) and the second upper corner location (TC2);
the fourth panel (P4) has a gable transverse fold line (431) defining a boundary between a top gusset sub-sub-panel (432) and a gable closure sub-sub-panel (433) of the third sub-panel (430) of the fourth panel (P4);
The carton blank (10, 30, 40, 50) according to any one of claims 1 to 4, wherein the fold line defined by the first diagonal crease line (435) of the fourth panel (P4) extends between the gable transverse crease line (431) of the fourth panel (P4) and the third upper corner location (TC3). the boundary defined by the horizontal fold line (250) of the second panel (P2) forms an obtuse angle (α) with the second vertical fold line portion (21c) when terminating at the second upper corner location (TC2);
The carton blank (10, 30, 40, 50) according to any one of claims 1 to 5, wherein the boundary defined by the horizontal fold line (450) of the fourth panel (P4) forms an obtuse angle (α) with the third vertical fold line portion (22c) when terminating at the third upper corner position (TC3). the transverse fold line (250) of the second panel (P2) terminates at the second upper corner location (TC2) while presenting a circular arc (250') having a first radius of curvature (R1);
the transverse fold line (450) of the fourth panel (P4) terminates at the third upper corner location (TC3) while presenting a circular arc (450') having the first radius of curvature (R1);
the first diagonal fold line (235) of the second panel (P2) terminates at the second upper corner location (TC2) while presenting an arc (235') having a second radius of curvature;
the first diagonal fold line (435) of the fourth panel (P4) terminates at the third upper corner location (TC3) while presenting a circular arc (435') having the second radius of curvature (R2);
The carton blank (10) according to any one of claims 1 to 6, wherein the second radius of curvature (R2) is smaller than the first radius of curvature (R1). The carton blank (10) of claim 7, wherein the second radius of curvature (R2) is any one of 20% to 80% of the first radius of curvature (R1), 40% to 60% of the first radius of curvature (R1), and 45% to 55% of the first radius of curvature (R1). the arc (235') of the first diagonal fold line (235) of the second panel (P2) has a center of curvature that lies on the second vertical fold line portion (21c);
9. The carton blank (10) of claim 8, wherein the arc (435') of the first diagonal fold line (435) of the fourth panel (P4) has a center of curvature that lies on the third longitudinal fold line portion (22c). the arc (250') of the horizontal fold line (250) of the second panel (P2) has a center of curvature located a lateral distance (D) in the second panel (P2) from the second vertical fold line portion (21c);
the arc (450') of the horizontal fold line (450) of the fourth panel (P4) has a center of curvature that is located a lateral distance (D) in the fourth panel (P4) from the third vertical fold line portion (22c);
The carton blank (10) according to any one of claims 7 to 9, wherein the lateral distance (D) is in the range of 40% to 90% of the first radius of curvature (R1). the second panel (P2) has a second diagonal fold line (234) that terminates at the first upper corner location (TC1) and defines a fold line in the third sub-panel (230) that forms an angle (β) of at least 70° with the first longitudinal fold line portion (20c);
The carton blank (40, 50) according to any one of claims 1 to 10, wherein the fourth panel (P4) has a second diagonal crease line (434) defining a fold line in the third sub-panel (430) that terminates at the fourth upper corner location (TC4) and forms an angle (β) of at least 70° with the fourth vertical crease line portion (23c). the second diagonal fold line (234) of the second panel (P2) has a diagonal fold line portion (234b) having a convex portion toward the transverse fold line (250) of the second panel (P2);
12. The carton blank (40, 50) of claim 11, wherein the second diagonal fold line (434) of the fourth panel (P4) has a diagonal fold portion (434b) having a convex portion toward the transverse fold line (450) of the fourth panel (P4). A carton blank (40, 50) according to any one of claims 11 and 12, wherein the angle (β) formed between the second diagonal crease line (234) of the second panel (P2) and the first vertical crease line portion (20c) is equal to the angle (β) formed between the second diagonal crease line (434) of the fourth panel (P4) and the fourth vertical crease line portion (23c). A gable top carton having a carton blank (10) according to any one of claims 1 to 13.

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