SK283511B6 - Fully enclosed wrap-around carton - Google Patents

Abstract

A blank for forming a carton for packaging a plurality of articles comprising a series of hingeably interconnected top, first side, bottom and second side panels (12, 14, 16, 18, 20) for forming an open-ended sleeve capable of receiving said articles, the top and bottom panels (12, 18, 20) being similarly non-rectangularly shaped substantially to correlate with the cross-sectional shape of the array of articles in a plan parallel to said top and bottom panels (12, 18, 20), wherein a gusset (38) comprising two hingeably connected gusset panels (58, 60) connects the first side panel (14) and top or bottom panel (12, 18, 20) which gusset (38) is adapted to facilitate movement of the first side panel (14) to correlate with the associated shape of a stowed array of articles during the formation of the carton (10).

Description

The present invention relates to cartons for wrapping a plurality of articles, such as cans or beverage bottles, and more particularly to cartons for wrapping multiple rows or layers of articles in a completely closed carton and cartons for wrapping articles in a non-rectangular configuration.

BACKGROUND OF THE INVENTION

A known carton having an upper panel and an octagonal base is described by an inventor named Chaussadas in U.S. Pat. No. 4,747,485. The carton comprises a plurality of separate panels for closing the sides and ends of the carton. A separate panel is hingedly attached to each of the eight top and base panels. Most of these panels essentially hang only halfway between the associated top and bottom panels and the opposing top and bottom panels, and therefore the associated panel hanging from the opposite top or bottom panel is overlapped. Therefore, a very complicated folding method is required when folding different panels, which should result in the closure shown in US 4,747,485.

the protruding tab preferably comprises said abutting edge.

Another feature of the present invention is to provide a blank for forming a carton wrapping a plurality of articles, the blank comprising a hinged interconnected main panel assembly to form an open-end carton into which said articles can be inserted when the two opposing panels have a similar non-rectangular shape to substantially conform to the cross-sectional shape of an arrangement of products whose plane is substantially parallel to the two opposing panels, and the two other main panels comprise a plurality of bending regions which are adapted to bend in at least three different planes to allow adapting said two other main panels to associated opposing panels, wherein a reinforcement comprising two hinged panels attaches the first main panel between adjacent bending regions and one of top panels facing each other.

Advantageously, an opening may be provided in the reinforcement to facilitate folding thereof, and the reinforcement may comprise means for closing said opening when the carton is folded. Further features of the invention relate to carton and carton folding.

SUMMARY OF THE INVENTION

The present invention seeks to overcome or at least alleviate the various problems of cartons already known in the art. According to one feature of the present invention, a blank for folding a carton for wrapping a plurality of articles is provided, comprising a plurality of hinged panels to form the top, bottom and sides in the form of an open-end carton into which the articles and top panel can be inserted. as well as the bottom panel are similarly non-rectangular in shape so that both panels substantially correspond to the cross-sectional shape of the article arrangement in a plane parallel to said top panel and said bottom panel when said side panels comprise a plurality of bending regions which are provided so as to be able to bend in at least three different planes, thereby allowing the side panels to adapt to both the associated top panel and the bottom panel, wherein a reinforcement comprising two hinged panels attaches the first side panel between adjacent bending regions and top and bottom panels.

The carton blank comprises two stiffeners between the first side panel and the top and bottom panels, which stiffeners cooperate with associated end portions of the first side panel to induce its movement during folding of the carton. Two reinforcements can connect both sides of the panels to the top panel and two reinforcements connect both sides of the panels to the bottom panel.

Each bending region may include a plurality of hinged parts and these hinged parts may be separated by curvilinear parts that form rounded corners of the assembled carton.

One of the stiffening panels may have a protruding tab for easier insertion of the tab into the carton during folding. One of the stiffening panels may also include means such as an edge that abuts the end of the carton to help maintain the associated side panel in its folded form in the carton. mentioned

Description of the drawings

An embodiment of the invention will now be described solely by way of describing the example with reference to the accompanying drawing, in which:

Fig. 1 is a plan view of a blank blank after folding a carton according to a first embodiment of the present invention.

Fig. 2 to 6 show different views of the blank of FIG. 1 during the folding process of the carton shown in FIG. 7 and 8.

Fig. 7 and 8 are perspective views of a folded carton according to a first embodiment of the present invention.

Fig. 9 is a plan view of a blank for folding a carton according to a second embodiment of the present invention.

Fig. 10 to 14 are perspective views of a carton according to a second embodiment of the present invention.

Fig. 15 is a plan view of a blank for folding a carton according to a third embodiment of the present invention.

Fig. 16 to 21 are various perspective views of a carton according to a third embodiment of the present invention.

Fig. 22 is a plan view of a blank for folding a carton according to a fourth embodiment of the present invention.

Fig. Figures 23 to 28 show views of various stages of folding carton from the blank blank shown in Figs. 22. FIG. 29 is a perspective view of a carton comprised of the blank blank shown in FIG. 22nd

Fig. 30 is a schematic representation of the method of filling and closing the carton shown in FIG. 29th

DETAILED DESCRIPTION OF THE INVENTION

A first embodiment of the present invention is shown in FIG.

1 to 8, wherein the carton 10 is comprised of a blank blank

II for folding the carton 10 is shown in FIG. 7 and 8. The carton is designed to maintain a non-rectangular configuration of articles, such as an arrangement comprising rows of two, three and two articles, and having a horizontal cross-sectional shape substantially in the form of a hexagon. Since products such as cans or bottles are generally cylindrical or at least have rounded sides for bottles, this hexagonal arrangement also has rounded corners. To be rigidly wrapped in such an arrangement, the carton 10 has bendable side panels. The carton 10 may hold one stack of higher products or two stacks of products in a stacked configuration. Of course, multiple product floors may also be positioned by simply adjusting the length of the side panels of the carton to meet the requirements of a predetermined number of floors. The blank 11 comprises a base panel 12 which is hingably connected to the end tabs 22 and 24 and to the side panels 14 and 16 via fold lines 56a and 56b and bottom stiffeners 40a, 40b, 40c and 40d as shown in FIG. 1. Both the side panel 14 and the side panel 16 comprise respective rows of side panel portions 42a and 42b, 46a and 46b, 50a and 50b and 54a and 54b. The side panel portions are separated from each other by the bendable panel portions 44a and 44b, 48a and 48b, and 52a and 52b. The bendable panel portions comprise a series of fold lines that allow a certain amount of bending of each panel portion to bend the side panels 14 and 16 around the coated products in an arc manner so as to be completely wrapped by the sides of the carton. Therefore, the cross-section of the carton taken along the horizontal plane is polygonal, in this case hexagonal, with curved or rounded corners.

The side panels 14 and 16 are respectively hingedly attached to the first top panel 18 and the second top panel 20. Said top panels 18 and 20 are hingedly connected to respective side panels 14 and 16 via reinforcements 38a, 38b, 38c and 38d and fold lines 64a, and 64b. The top panels are of the overlapping type and may be joined together using glue or cooperating locking means such as tabs and openings. The top panel 18 comprises end tabs 26b and 28b that are hingedly attached thereto along respective fold lines 25c and 25d. The notch features 33c and 33d are disposed on the fold line between the first top panel 18 and each of the end tabs 26b and 28b, but in other embodiments only one such notch feature may be formed, or no such notch feature may be provided. These notch features 33c and 33d allow the fold line between the side tabs and the first top panel to be bent when a handle is used, as will be described. The handle 30 is formed on the second top panel 20 and comprises a strap having finger loops 32 which are foldably attached to said strap. The second top panel 20 is foldably connected to end tabs 26a and 28a on respective fold lines 25a and 25b, and in this example, the ends of the handle strip extend to end tabs 26a and 28a along side slits 33a and 33b. The second top panel 20 also includes a handle reinforcement panel 36, which in this example is hingedly attached to the handle strip 30 along the fold lines 34.

Each of the reinforcements 38a, 38b, 38c and 38d may, as shown in FIG. 2, include an outermost panel 58 that is hingably connected to the nearest panel 60. A notch 62 may be used to separate a portion of the panel 58 from the panel 60 and the associated top panel 18 or 20. This notch 62 may be useful to define a protrusion 59 from the outermost reinforcement panel. 58, wherein the projection or folding means may be used to retain the reinforcement within the carton and thereby assist in folding the sides of the carton. The lower reinforcements 40a, 40b, 40c and 40d could be formed in the same way, but here each includes two symmetrical panels that are hingedly connected to each other along the fold line 41.

The method of folding the blank 11 into the form of a complete carton 10 shown in FIG. 7 and 8 is shown in FIG. First, the first top panel 18 may be folded according to the fold line 64b to be placed on the side panel 14. Then, the reinforcement panel may be folded along the fold line 34 below the handle strip 30 to form a two-layer handle and thus also this handle is reinforced. The side panel 16 and the second top panel 20 may then be folded along the hinge line 56a into the shape shown in FIG. 3. Subsequently, it is possible to attach the first top panel to the second top panel by, for example, gluing the overlapping portions or by using cooperating locking means (not shown) such as locking tabs and openings. Other panels may be used as overlay panels to allow the formation of a cylindrical box.

The edges of the handle at the cuts or notches 33a and 33b substantially follow the notch features 33c and 33d in the first top panel 18 to allow movement of the hinge or fold lines 25a, 25b, 25c and 25d between the top panels and the end tabs 26a, 28a and 26b, 28b. This allows in-use springing of the handle strip 30 upward due to the inward movement of the portion of the handle strip adjacent to the ends of the carton. In order to assist this movement, for example, a pair of lateral folding or folding lines 35c and 35d may be formed in the first top panel 18, as shown in FIG. In this example, both the fold lines 35c, 35d and associated portions of the fold lines 25c, 25d, which are directed across the swiveling portion guided between the end tab and the top panel, assist in said deflection inward when the handle 30 is used.

Then, the composite blank may be opened to form a box-like structure as shown in FIG. 4. In this form, articles such as cans can be inserted into the partially folded carton 10 by its open ends. After insertion of the articles, the end tabs 22 and 24 may be bent upward while the end tabs 26a, 26b, 28a and 28b may be bent downward. Subsequently, the side panels 14 and 16 may be folded around the article to close the ends of the carton. For example, the reinforcements 38a, 38b, 38c and 38d may be folded to a position below the associated top panel 18 or 20 by pressing the panel 58 and / or panel 60 of one or more reinforcements 38. Folding the reinforcements 38a to 38d down causes the ends of the side panels 14 and 16 are closed at the ends of the carton 10. Similarly, bending down the stiffeners 40a to 40d relative to the carton 10 may cause the bottom of the side panels 14 and 16 to pivot so as to close the ends of the carton.

The associated outermost end portions of the side panels 14 and 16 are thus brought into a relative overlap relationship as shown in FIG. 7. To keep the carton in a closed form, the outermost end portions 54a and 54b may be secured together by, for example, gluing or using cooperating locking means such as locking tabs and openings. Either one or both of the outermost end portions 54a and 54b may be attached to either or both end tabs 26a and / or 26b, or to the end tab 22. In this sense, the overlapping portions may be secured together. Similarly, the opposite ends of the carton may be maintained in the closed position to form the fully closed carton 10 shown in FIG. 7 and 8.

It can be seen that the carton 10 is designed to completely and firmly enclose the article assembly, and to this end has bendable side panels that firmly enclose the articles. The carton gives the aesthetic impression by having a suitably shaped top and bottom panels that follow the non-rectangular shape of the assembly of the insert products. Of course, other non-rectangular assemblies, such as e.g. triangular, rhombic and octagonal arrangements.

A second embodiment of the carton 110 of the present invention is shown in FIG. 9 to 14. In this embodiment, features or components similar to those described in the first embodiment are identified by the same two-digit reference numbers, with the number 1 being added before the two digits. Thus, the first top panel 118 is hingedly attached to the side panel. 114, which is further hingedly attached to the base panel 112. The base panel 112 is attached to a second side panel 116, which is hingedly attached to the second top panel 120. In this case, the handle notches 133 are substantially similar to their analogues in the previous embodiment, but the fold lines 135c may be formed to define a displaceable portion 131c following the respective fold lines 125c and 125d between the top panel 118 and the respective end panels 126b and 128b. Alternatively, the lines indicated by reference numeral 135c may be slit lines, thereby forming an opening 131c at the fold lines between the first top panel 118 and the end panels 126b and 128b.

In the side panels 114 and 116, the central bendable portions described in the first embodiment are replaced by the central panel portions 148a and 148b, and the other side panel portions may simply be hingedly connected by a single fold line. In this embodiment, the side panels are adapted to wrap the sides of the article assembly and completely enclose their sides. However, the base panel 112 and the top panel formed by the panels 118 and 120 do not have completely rounded corners, but have the shape of an irregular octagon. In this example, there is an intention to place an assembly with rows of one, two, two and one product on one or each floor. The present blank 111 is adapted to retain two floors or layering such assemblies, e.g. cans.

The side panels are hingedly attached to the associated top panel by stiffeners 138, which may include a main panel 158, for example, hingedly attached to the associated side panel 114 and 116, and the small panel 160 is hingedly attached to the main reinforcement panel.

158, as well as the associated top panel 116 or 120. A discrete notch 162 may be used to separate the panel 158 from the panel 160 and the associated top panel 118 or 120.

This notch 162 may usefully define a projection

159, which can be used to push the reinforcement 138 into position between the associated top panel 118 or 120 and the articles inside the carton 110. In other words, the shape of the reinforcement panels is designed to assist in folding the side panels to close the carton after filling . Also, the rim 157 formed here on each main reinforcement panel 158 cooperates in folding the carton with the end panel 126 or 128 to maintain the molded shape of the side panels.

All side panels 114 and 116 in this example have removable portions 170a and 170b. These parts may be prepared on the carton blank in part at least according to the tear line 174 and the fold lines 153 and 156 as shown in FIG. 9. The removable portions 170 may include means to assist in removing this portion of the carton, such as finger openings 172. These finger openings can be closed until they are used by hanging tab parts.

The carton 110 may be formed by folding the blank 111 in a manner substantially similar to that set forth in relation to the first embodiment. Thus, the top panel 118 may be folded along the fold line 164b, the side panel 116 and the top panel 120 may be folded along the fold line 156a, and subsequently the overlapping portions of the top panels may be secured together. Then, a cardboard box may be formed which is filled with products before bending the side panels 114 and 116 and closing the ends by folding the end panels 12,124,126a, 128a, 126a, 128a, 126b and 128b according to their respective fold lines.

The openable portions 170 preferably allow removal of the article A from the carton 110 without tearing the entire carton when it is opened. In FIG. 10 and 11, it is shown that the openable and closable portions 172b can be opened by breaking the tear line 174 and opening the panel 170b according to the fold line 153b. In addition, a tear line 161c may be formed in the reinforcement 138c between the reinforcement panels 158c and 160c (see FIG. 9), which allows the opening panel 170b to be fully opened. In FIG. 12, it can be seen that the carton 110 can wrap two product layouts that can be separated, for example, by a partition panel 176. In order to gain access to a lower product layering, a second openable or removable portion 170a can be formed. On opening, the opening portion 170a is folded along the hinge line 143, while the tear-off tear mark 174 and the tear-off fold line 141b are between the reinforcement panels 140b (see FIG. 9). Of course, the stiffeners should be designed so as to allow the opening of the openable panels without the need for additional tear-off markings, such as the aforementioned lines 161c or 141b.

In this example, in addition, the stiffening panels 138 are folded under the associated top panel by folding the stiffening panels 158 and 160 together according to the fold line 161 so that both parts are folded under the top panel. Thus, the main reinforcement panel 158 may lie adjacent the fold line 125 between the end panels 126a, 126b, 128a, or 128b at their edge 157, thereby strengthening the fold line between the side panels and upwardly to the handle strip and positively effecting the shape of the side panels.

Referring to the blank and carton shown in FIG. 15 to 20, a third embodiment of a carton according to the present invention will now be described. In this example of the present invention, features or components similar to those described in the first two embodiments are indicated by the same two-digit reference numbers, with the number 2 being added before this two-digit number. Thus, the first top panel 218 is hingedly attached to the side panel. 214, which is further hingedly attached to the base panel 212. The second side panel 216 is hingedly attached to both the base panel 212 and the second top panel 220. The side panels 214 and 216 are substantially similar to the side panels shown in FIG. Fig. 9 and correspondingly described, and have different configurations only in relation to the opening (and / or removable) portions 270. In this example, the tear line 274 extends substantially along three sides of the rectangular panel forming the removable portion 270. The openable portions 270a and 270b are hingedly coupled to the fourth side according to respective fold lines 239b and 237c. Each of these fold lines connects the opening portions 270a and 270b to the associated reinforcement panel, in this case namely the respective reinforcement panel 240b and 238c.

The openable portions 270b can be folded along the fold line 237c on the assembled carton shown in FIG. The portion 270b may be removed by peeling along the fold line 261c as shown in FIG. 18 so that it is possible to remove the top layer products A from the form of carton shown in FIG. 19. The lower opening portion 270a can likewise be opened by folding along the fold line 239b. Also, the portion 270a can be completely removed by tearing, for example, according to the fold line 241b.

In this example, the carton 210 is adapted to wrap three product layouts, each layer comprising an array of rows of one, two, two and one product. Of course, it is possible to wrap a different number of rows with different numbers of articles and also a different number of layering can be placed inside the carton after making appropriate adjustments to the blank blank described herein.

A fourth embodiment of the blank 311 and the carton formed therefrom is shown in FIG. 22 to 30. The folded carton 310 shown in FIGS. 29, has a generally octagonal cross-section in a horizontal plane and is designed to wrap a single-layered assembly of products such as bottles in an arrangement of three, four, four and three products in a row.

The yarn blank 311 comprises a top panel 320 that is hingably connected to the side panel 316 according to the fold line 364a. The side panel 316 is further hingedly attached to a base panel having an octagonal shape. The base panel 312 is connected to the second side panel 314 according to the fold line 356b. In this embodiment, instead of forming overlapping panels forming the blank blank into a tubular box of similar structure, a tab 315. is applied. by gluing or using locking means such as locking tabs and openings.

The yarn blank 311 comprises a handle 330 having grip tabs 332 in the top panel 320 and a handle reinforcing the strip 336, which in this case is hingedly attached to the end panels 326 and 328, which are hingably attached to the top panel 320. folding, divergent lines forming a marking 380 to relieve the pressures when the handle is used. In this embodiment, the openable markings 370 are formed in the top panel 320.

The openable markings 370 follow the openings defined by the gripping tabs 332 which form part of the handle 330 and have lateral tear lines similar to lines 274 and 174, which have already been shown in connection with the second and third embodiments. When fastening the tab 315 to the side panel 314, four effective reinforcements 338 are formed between the top panel 320 and the side panels of the carton. The reinforcements 338 are the same in this example, and with reference to the reinforcement 338a it can be seen that they comprise a main panel 358a that is hingedly attached to the side panel 316. The main panel 358a is hingedly attached to a small panel 360a which is hingedly attached to the top panel 320. The main reinforcement panel 358a includes a protruding tab 359a that can be used to close the carton and keep the associated sidewalls in a rounded shape due to cooperation, for example, between the edge 357a and tab 359a and the end panel 328. This cooperation will be clearer with other drawings. . In addition, the reinforcement panel 358 may be positioned between the associated, for example, a corner top of the article, such as a bottle stopper, and the top panel 320. This may help protect each opening on top of the carton when folded despite the opening 363 formed by the reinforcement.

The side walls 316 and 314 are the same and comprise a main center panel having a respective center fold line 385a and 385b that allows the two sides of these panels to be folded substantially in half. This is advantageous when preparing the possibility of erecting the partially folded carton shown in FIG. 25 to the box-like structure shown in FIG. 26 and into which the relevant products can be inserted. The intermediate fold lines 385a and 385b are directed to the side panel portions 346a, 350a, 346b and 350b. In addition, at each fold line 385 in the side portions of the side panels, a reinforcement 386 is formed. These reinforcements 386 facilitate better wrapping of the sides and ends of the intermediate products and the formation of slanted upper portions of the side panels, which can be seen in FIG. For this purpose, the end fold lines 323a and 323b are also formed in respective lower end panels 324, 322. It is clear that in order to form a tapered top, the top panel 320 should be a smaller octagon than the base panel 312. as in other embodiments, reinforcements 340 may be formed between the base panel 312 and the side panels.

For folding of the carton 310, the stiffening strip 336 is folded along the fold line 334 to the position shown in FIG. Thus, the openings 382 in the strip 336 are aligned with the fold lines 325a and 325b, thereby minimizing any interference with the folding of the upper end panels 328 and 326 according to the fold line 325a and 325b when the ends of the filled carton are closed. Further, both the top panel 320 and the side panel 316 are folded according to the fold line 385a to the position shown in FIG. 24. The upper portion of the side panel 314 is then folded along the fold line 385b so that it touches the tab 315 and can be attached thereto, for example by gluing, thereby forming the flat structure shown in FIG. The blank blanks 311 can usually be stored in this flat form and transported to the packaging mechanism as packaging materials that are ready to be placed in suitable containers, such as the container H shown schematically in FIG. 30th

In order to be able to insert the products into the carton structure shown in FIG. 25, the carton is first erected to the carton as shown in FIG. This is also shown in the initial part of the packaging process shown in FIG. 30, it being clear that the carton is moving in the direction of operation indicated by the arrow F. In this schematic drawing, it can be seen that in phase A, the previously unsealed product lines are arranged into the desired double-row formations at both ends of the carton. rows of four products and two adjacent outer rows of three products. The outer row is slightly displaced with respect to the inner row so that the product rows are positioned so as to form a relatively tightly wrapped assembly. This means that one product in the outer row relies on two products in the inner row. This does not apply to the contact of the two inner rows after being placed in the carton during the phase indicated by section B in FIG. 30. Adjacent inner rows of four products rely on each other only by one product relying on a neighboring product adjacent to each other.

EN 283511 Β6 inner row. Of course, for different dimensions or shapes, it would be possible to produce different aligned product assemblies in a carton.

After the carton 320 has been filled, the reinforcements 338 and 340 are bent inwards as they pass through the operating section C. In the ring G in FIG. 30, it is shown that the main reinforcement panel 358c is inwardly bent to a position below the top panel 320. Also, the reinforcements 340 are bent upward as shown in the ring H in FIG. 30. This bending of the stiffeners causes the side panels to bend toward the partially closed structure shown in FIG. The outermost end portions of the side panels 350a and 350b may then be further drawn around the ends of the cartons, as seen in section D of FIG. 30. This causes further rounding of the side panels 304 and 316, thus copying the sides of adjacent products and conforming to the three sides of the octagonal base panel 312 and the top panel 320. In addition, the upper portions of the side panels 314 and 316 are skewed or bent inwardly thereby copy the extension under the neck of the bottles stored in the carton.

The upper and lower end panels 322, 324, 328 and 326 are then bent according to the associated fold line to the upper or lower panel as shown in FIG. The associated upper and lower end panels, such as panels 328 and 322, may then be secured together by, for example, gluing. Alternatively, cooperating locking means such as locking tabs and openings may be used for this purpose. The end panels may also be attached to the end panels 346a, 346b, 350a and 350b. If adhesive means are used as an adhesive, then the carton shown in FIG. 29, compressed in section E of FIG. 30 to ensure that the panels remain closed.

Claims (10)

1. A blank for folding carton for wrapping articles, comprising an arrangement of hingedly coupled first top, second top panels, and side panels to form an open-end carton having the ability to receive articles when the top panels have a non-rectangular shape corresponding to the cross-sectional shape of the article assembly. which is horizontal with respect to the top panels, characterized in that each of the side panels (14, 16) comprises bendable panel portions (44b, 48b, 52b) spaced apart from each other by the side panel portions (42a) , 42b, 46a, 46b, 50a, 50b, 54a, 54b), and adapted to position these portions in at least three different planes and to adapt the side panel (14, 16) to the shape of the associated and / or second top panel, further comprising reinforcements ( 38a, 38b, 38c, 38d) with two lower stiffeners (40a, 40b, 40c, 40d) to attach the side pan regions eluting (14, 16) to the respective first top panel (18) or second top panel (20). A carton blank according to claim 1, characterized in that it comprises two stiffeners (38a, 38b, 38c, 38d) connected between the side panel portions (46a, 46b, 50a, 50b) of the side panels (14, 18). and a respective top or bottom panel (18, 20) for cooperating with associated end portions of the first side panel (14) to induce its movement during folding. Cardboard blank according to claim 2, characterized in that two stiffeners (38a to 38d) are connected to both side panels (14, 16) to the top panel (18, 20) and two bottom stiffeners (40a to 38d). 40d) are connected by the side panels (14, 16) to the base panel (12). A carton blank according to any one of claims 1 to 3, wherein each bendable panel part (44b, 48b, 52b) comprises a plurality of hinged parts. Cardboard blank according to claim 4, characterized in that the hinged parts are separated by curved parts forming rounded corners. Cardboard blank according to any one of claims 1 to 5, characterized in that one of the stiffeners (38a, 38b) comprises a projection (59) projecting therefrom. A carton blank according to any one of the preceding claims, characterized in that it comprises main reinforcement panels (158, 358a) with contact edges (157, 357a) for effectively touching the end of the carton. Cardboard blank according to claim 6 and 7, characterized in that the contact edge (357a) is provided with a projecting tab (359a). A carton blank according to any one of claims 1 to 8, characterized in that the main reinforcement panel (358a) has an associated opening (363a). A carton blank according to claim 9, wherein the stiffening panel (358a) comprises means for closing the opening (363a) during the forming of the carton.