US20090242435A1

US20090242435A1 - Pack for smoking articles

Info

Publication number: US20090242435A1
Application number: US12/409,891
Authority: US
Inventors: Marcel Van Rijssel
Original assignee: Philip Morris USA Inc
Current assignee: Philip Morris USA Inc
Priority date: 2008-03-25
Filing date: 2009-03-24
Publication date: 2009-10-01
Also published as: PT2268550E; EP2268550A1; JP2011515288A; MY153352A; WO2009118147A1; BRPI0911138A2; EP2268550B1; PL2268550T3; ES2437151T3; EP2105385A1; MX2010010524A; BRPI0911138B1

Abstract

A pack for smoking articles substantially in the form of a generally rectangular parallelepiped includes a pair of opposed major side walls; a pair of opposed minor side walls; four longitudinal edges between the major and minor side walls; and a pair of substantially rectangular opposed end faces defined by transverse edges of the major and minor side walls. At least one of the opposed substantially rectangular end faces is an open end face defined by free transverse edges of the major and minor side walls, at least one of the four longitudinal edges has a non-right-angled portion and the transverse perimeter of the pack is substantially constant. The pack is preferably formed from a folded blank and the non-right-angled portion is preferably defined by at least three lines of weakness in the blank.

Description

CROSS REFERENCE TO RELATED APPLICATIONS

This application corresponds to European Application No. EP 08251038, filed Mar. 25, 2008, which is incorporated herein by this reference thereto.

BACKGROUND

The present invention relates generally to a pack for smoking articles with one or more bevelled or rounded longitudinal edges and in particular to a rigid cup pack with one or more bevelled or rounded longitudinal edges.
Cigarettes are commonly packaged in three separate wrappings, namely an inner liner, a soft or rigid outer pack and an overwrapper. The inner liner in the form of, for example, metal foil or metallized paper is wrapped around a bundle of cigarettes and folded in at the ends of the bundle. A printed cardboard or paper blank is folded around the bundle of cigarettes and inner liner to form a soft or rigid outer pack. Depending on the number of walls thereof, these outer packs are commonly referred to in the art as having the form of a sleeve, cup or box. A ‘sleeve’ pack typically has four side walls and open upper and lower ends. A ‘cup’ pack typically has four side walls, a bottom wall and an open upper end. A ‘box’ pack typically has four side walls, a bottom wall and a top wall. To preserve the freshness of the bundle of cigarettes, the pack is shrink wrapped with an overwrapper of, for example, polyethylene or polypropylene film, which typically includes a tear tape to facilitate opening thereof.
Rigid packs for cigarettes are normally substantially in the form of a generally rectangular parallelepiped with two major side walls and two minor side walls connected along right-angled longitudinal edges. When an overwrapper is wrapped around a generally rectangular parallelepipedal rigid pack, generally rectangular folded sections of the overwrapper are created at the upper and lower ends of the pack.
Rigid packs having one or more bevelled or rounded longitudinal edges, formed by scoring the cardboard blank that is folded to produce the rigid pack, are also known. Rigid packs with bevelled or rounded longitudinal edges are advantageously more ergonomic than those with right-angled longitudinal edges and may result in reduced wear on consumers' garments and bags. However, the upper and lower ends of such packs are not rectangular, but instead have ‘missing corners’ due to the bevelled or rounded longitudinal edges of the pack. When an overwrapper is wrapped around a rigid pack with bevelled or rounded longitudinal edges, rectangular folded sections of the overwrapper are still created at the upper and lower ends of the pack. These rectangular folded sections of the overwrapper do not follow the shape of the bevelled or rounded upper and lower corners of the pack. Instead, the right-angled corners of the rectangular folded sections of the overwrapper protrude beyond the bevelled or rounded upper and lower corners of the pack. Consequently, to avoid unsightly folds, it is necessary for the overwrappers of rigid packs with bevelled or rounded longitudinal edges to be shrunk more at the upper and lower corners of the pack than the overwrappers of rigid generally rectangular parallelepipedal packs.
In rigid cup packs, the upper end of the pack is open and has a tendency to deform inwards when a rigid cup pack with bevelled or rounded longitudinal edges is shrink wrapped with an overwrapper due to the forces created by the additional shrinkage necessary to compensate for the ‘missing corners’. As a result, where rigid cup packs have bevelled or rounded longitudinal edges, it is not possible to additionally shrink the transparent overwrapper at the upper and lower corners of the pack without producing unsightly wrinkles in the overwrapper.
It would be desirable to produce a pack for smoking articles with bevelled or rounded longitudinal edges that can be overwrapped without the need for additional shrinkage of the transparent overwrapper at the upper and lower corners or the pack or along the bevelled or rounded longitudinal edges thereof.

SUMMARY OF SELECTED ASPECTS OF THE INVENTION

According to the present invention there is provided a pack for smoking articles substantially in the form of a generally rectangular parallelepiped, the pack comprising: a pair of opposed major side walls; a pair of opposed minor side walls; four longitudinal edges between the major and minor side walls; and a pair of opposed substantially rectangular end faces defined by transverse edges of the major and minor side walls, wherein at least one of the opposed substantially rectangular end faces is an open end face defined by free transverse edges of the major and minor side walls, at least one of the four longitudinal edges includes a non-right-angled portion and the transverse perimeter of the pack is substantially constant.
Throughout the specification, transverse perimeter is used to denote the distance around the major and minor side walls of the pack, in a plane generally perpendicular to the longitudinal axis of the pack.
The combination of opposed generally rectangular end faces and a substantially constant transverse perimeter advantageously allows packs according to the invention to be overwrapped without the need for additional shrinkage of the overwrapper at either the upper and lower corners of the pack or along the four longitudinal edges of the pack.
When folded over the opposed generally rectangular end faces of packs according to the invention, an overwrapper follows the shape of the substantially right-angled corners of the opposed substantially rectangular end faces of the pack. Furthermore, as the transverse perimeter of packs according to the invention is substantially constant, additional shrinkage of the overwrapper is also not required in order to make the overwrapper follow the shape of the longitudinal edges of the pack. The substantially constant transverse perimeter means that the transverse perimeter of the opposed substantially rectangular end faces of packs according to the invention is substantially the same as the transverse perimeter around non-right-angled portions of the four longitudinal edges thereof. This advantageously facilitates getting a smooth, wrinkle free overwrapper when packs according to the invention are overwrapped.
At least one of the four longitudinal edges may have a non-right-angled, flat bevelled portion. For example, at least one of the four longitudinal edges may have a flat bevelled portion inclined at between about 30 degrees and about 60 degrees, preferably at about 45 degrees, to the adjacent major and minor side walls of the pack.
Alternatively, or in addition, at least one of the four longitudinal edges may have a non-right-angled, rounded portion of substantially curved cross-section. For example, at least one of the four longitudinal edges may have a rounded portion of substantially outwardly convex transverse cross-section. Alternatively or in addition, at least one of the four longitudinal edges may have a rounded portion of substantially outwardly concave transverse cross-section.
Preferably, each of the four longitudinal edges includes a non-right-angled-portion.
In a preferred embodiment of the invention, each of the four longitudinal edges of the pack has a non-right-angled, flat bevelled portion. In another preferred embodiment of the invention, each of the four longitudinal edges of the pack has a non-right-angled, rounded portion of substantially curved transverse cross-section. However, in alternative embodiments of the invention, at least a first one of the four longitudinal edges of the pack has a non-right-angled, flat bevelled portion and at least a second one of the four longitudinal edges has a non-right-angled, rounded portion of substantially curved cross-section. For example, each of a first pair of the four longitudinal edges may have a non-right-angled, flat bevelled portion and each of a second pair of the four longitudinal edges may have a non-right-angled, rounded portion of substantially curved cross-section.
Preferably, at least one of the four longitudinal edges has a pair of opposed substantially right-angled portions adjacent the opposed substantially rectangular end faces and a non-right-angled portion disposed between the pair of substantially right-angled portions. The pair of opposed substantially right-angled portions may be of the same or different length.
More preferably, at least one of the four longitudinal edges has a pair of opposed substantially right-angled minor portions adjacent the opposed substantially rectangular end faces and a non-right-angled major portion disposed between the pair of substantially right-angled portions.
In a preferred embodiment of the invention, each of the four longitudinal edges has a pair of opposed substantially right-angled minor portions adjacent the opposed substantially rectangular end faces and a non-right-angled major portion disposed between the pair of substantially right-angled minor portions.
Packs according to the invention may be formed from any suitable known material or combination of materials used for packaging including, but not limited to, paper, cardboard, paperboard, metals, such as aluminum, or plastics.
Packs according to the invention are preferably formed from folded blanks, more preferably from folded cardboard blanks, most preferably from folded cardboard blanks with a weight of between about 200 grams per square meter and about 400 grams per square meter. In a particularly preferred embodiment of the invention, the pack is formed from a folded cardboard blank with a weight about 250 grams per square meter.
Preferably, the pack is formed from a folded blank and at least one of the four longitudinal edges has a non-right-angled portion formed by two or more longitudinal lines of weakness in the blank. More preferably, at least one of the four longitudinal edges has a non-right-angled portion formed by between two and five longitudinal lines of weakness in the blank
The term “line of weakness” is used in the present specification to describe a line formed by compressing or partially cutting the blank by creasing, scoring, embossing or an equivalent known process.
For example, at least one of the four longitudinal edges may have a non-right-angled, flat bevelled portion formed by two longitudinal lines of weakness in the blank. Alternatively or in addition, at least one of the four longitudinal edges may have a non-right-angled, rounded portion of substantially curved transverse cross-section formed by three or more longitudinal lines of weakness in the blank.
Preferably, at least one the four longitudinal edges has a non-right-angled portion formed by at least three longitudinal lines of weakness in the blank. More preferably, at least one the four longitudinal edges has a non-right-angled portion formed by between three and five longitudinal lines of weakness in the blank.
Formation of the non-right-angled portion from at least three longitudinal lines of weakness advantageously increases the curvature of the non-right-angled portion of the longitudinal edge and gives the pack a rounded and ergonomic appearance.
The non-right-angled portion may be formed by two or more straight longitudinal lines of weakness in the blank or by two or more curved longitudinal lines of weakness in the blank or by a combination of at least one straight longitudinal line of weakness and at least one curved longitudinal line of weakness in the blank.
In a preferred embodiment, at least one the four longitudinal edges has a non-right-angled portion formed by at least three substantially generally parallel, straight longitudinal lines of weakness in the blank.
At least one of the four longitudinal edges may have a non-right-angled portion formed from at least two longitudinal lines of weakness in the blank that extend from the respective adjacent major side wall of the pack into the respective adjacent minor side wall of the pack. This gives the impression that the non-right-angled portion is ‘twisted’ around the longitudinal edge of the pack.
Preferably, at least one of the opposed substantially rectangular end faces is defined by free transverse edges of the major and minor side walls. More preferably, one of the opposed substantially rectangular end faces is defined by free transverse edges of the major and minor side walls and the other one of the opposed substantially rectangular end faces defined by transverse edges of the major and minor side walls is a substantially rectangular end wall of the pack.
Packs according to the invention are preferably rigid cup packs with an upper substantially rectangular end face defined by free transverse edges of the major and minor side walls and a lower substantially rectangular end wall. However, it will be appreciated that packs according to the invention may also be other known types of packs for smoking articles including, but not limited to, hinge-lid packs, slide and shell packs, shoulder packs and booklet packs.
Packs according to the invention may be overwrapped in a known manner with any suitable known material or combination of materials including, but not limited to, cellophane, polymeric films of, for example, polyethylene or oriented polypropylene, metallized polymeric films and laminated polymeric films.
Preferably, packs according to the invention are shrink wrapped with a transparent overwrapper. More preferably, packs according to the invention are shrink wrapped with a transparent overwrapper of polyethylene or polypropylene film.
Packs according to the invention may be overwrapped with overwrappers including one or more tear tapes. The one or more tear tapes may extend in a transverse or longitudinal direction around the perimeter of the pack.
Packs according to the invention may be used to house smoking articles including, but not limited to, conventional lit-end cigarettes, cigars, cigarillos, heated cigarettes (for example cigarettes comprising a combustible heat source or fuel element (for example cigarettes of the type disclosed in U.S. Pat. No. 4,714,082) and cigarettes for use with electrical smoking systems (for example cigarettes of the type disclosed in U.S. Pat. No. 5,692,525)).
Through an appropriate choice of the dimensions thereof, packs according to the invention may be designed to house a total of about 6 to about 25 smoking articles, for example, ten, fifteen sixteen, seventeen, eighteen, nineteen, twenty, twenty-one or twenty-five smoking articles. Smoking articles housed in packs according to the invention may be arranged in different collations, depending on their total number. For example, packs according to the invention may house smoking articles arranged: in one row of six, seven, eight, nine or ten; in two rows of five, six, seven, eight, nine or ten; in two rows in a 5-6, 6-7 or 7-8 collation; in three rows of five or seven; in three rows in a 5-6-5, 6-5-6, 5-6-7, 6-7-5, 7-5-7, 7-6-7, or 8-9-8 collation; or in four rows of four, five or six.
Alternatively or in addition, packs according to the invention may be designed to house smoking articles of different dimensions (for example, smoking articles of different length or different circumference). Packs according to the invention may, for example, be designed to house different numbers of short (between about 60 mm and about 65 mm in length), regular size (about 70 mm in length), king size (about 75 mm in length), super-king size, slim, super-slim or wide cigarettes. Cigarettes or other smoking articles housed within packs according to the invention may be of round or oval transverse cross-section.
Packs according to the invention preferably further comprise an inner liner, which is wrapped around a bundle of smoking articles housed in the pack. Preferably, the inner liner is formed from a substantially air impermeable material. In a preferred embodiment, the inner wrapper is sealed to form a substantially an airtight wrapped bundle of smoking articles. Preferably, the inner liner comprises a reclosable flap that allows the consumer to open and re-close the wrapped bundle of smoking articles.
The exterior surfaces of packs according to the invention may be printed, embossed, debossed or otherwise embellished (for example using labels or stickers) with manufacturer or brand logos, trade marks, slogans and other consumer information and indicia.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described, by way of example only, with reference to the accompanying drawings wherein like reference numerals are applied to like elements and wherein:

FIG. 1 is a perspective view of an empty rigid cup pack according to a first embodiment of the invention;

FIG. 2 is an side elevational view of the pack shown in FIG. 1;

FIG. 3 is a plan view of a blank for forming the pack of FIG. 1;

FIG. 4 a is an enlarged perspective view of an upper corner of the pack of FIG. 1;

FIG. 4 b is an enlarged perspective view of an upper corner of a rigid cup pack according to a second embodiment of the invention;

FIG. 4 c is an enlarged perspective view of an upper corner of a rigid cup pack according to a third embodiment of the invention; and

FIG. 5 is a perspective view of a longitudinal edge of a rigid cup pack according to a fourth embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

An empty rigid cup pack 2 according to the first embodiment of the invention shown in FIG. 1 is substantially in the form of a generally rectangular parallelepiped and comprises: a major front wall 4 and an opposed major rear wall 6; a first minor side wall 8 and an opposed second minor side wall 10; and a lower generally rectangular end wall 12 and an opposed open upper generally rectangular end face 14, which is defined by upper transverse free edges of the major front wall 4, major rear wall 6, first minor side wall 8 and second minor side wall 10.
The terms “front”, “rear”, “lower” and “upper” are used in the present specification to describe the relative positions of the walls, ends and faces of a rigid cup pack when the rigid cup pack is in an upright position with the open end face thereof at the top of the pack. When describing packs according to the present invention, these terms are used irrespective of the orientation of the rigid cup pack being described.
The first minor side wall 8 and the second minor side wall 10 are each connected to the major front wall 6 and the major rear wall 10 along a pair of opposed longitudinal edges 18. As shown in FIG. 1, each of the longitudinal edges 18 includes a pair of opposed minor right-angled portions 18 a adjacent the lower end wall 12 and the open upper end face 14 of the pack 2, and a major, non-right-angled, flat bevelled portion 20 disposed between the pair of opposed right-angled portions 18 a. It will be appreciated that, in alternative embodiments (not shown) the opposed right angled-portions 18 a may be of different length or may be omitted. The major non-right-angled, flat bevelled portion 20 of each longitudinal edge 16 is inclined at about 45 degrees to the major wall 6, 10 and minor side wall 8, 10 of the pack 2 adjacent to the longitudinal edge 16. Where the rigid cup pack 2 houses smoking articles, the height of the rigid cup pack 2 preferably substantially corresponds to the length of the smoking articles.
FIG. 2 shows a side elevational view of the rigid cup pack 2 according to the first embodiment of the invention. As shown in FIG. 2, the major front wall 4 and major rear wall 6 of the rigid cup pack 2 are slightly outwardly convex in the region of the major non-right-angled, flat bevelled portions 20 of the four longitudinal edges 16. The transverse perimeter of the rigid cup pack 2 according to the first embodiment of the invention thus remains substantially constant.
An elongate one-piece cardboard blank 22 for forming the rigid cup pack 2 according to the first embodiment of the invention is shown in FIG. 3; the same reference numbers are used in FIG. 3 for parts of the blank 22 corresponding to parts of the pack 2. In FIG. 3, solid lines are used to denote cut lines or outer borders of the blank 22. Dashed lines are used to denote lines of weakness, which are formed by compressing or partially cutting the cardboard of the blank 22. The blank 22 is bent along the lines of weakness upon erection of the rigid cup pack 2. The lines of weakness are formed for example by creasing, scoring, embossing or an equivalent process.
The blank 22 comprises a major front wall panel 4 and a major rear wall panel 6 separated in the longitudinal direction of the blank 22 by a lower generally rectangular end wall panel 12. Opposed first 8 a and second 10 a outer minor side walls panels are connected to either side of the major front wall panel 4 along longitudinal lines of weakness, which form the longitudinal edges 16 of the erected rigid cup pack 2. Opposed first 8 b and second 10 b inner minor side walls panels are connected to either side of the major rear wall panel 6 along longitudinal lines of weakness, which form the longitudinal edges 18 of the erected rigid cup pack 2. As shown in FIG. 3, the major non-right-angled, flat bevelled portion 20 of each longitudinal edge 18 is formed by a pair of generally parallel, spaced apart, straight longitudinal lines of weakness that converge at the ends of the opposed right-angled portions 18 a of the longitudinal edge 18.
In an alternative embodiment (not shown), in which the pairs of opposed minor right-angled portions 18 a of the four longitudinal edges 18 of the pack 2 are omitted, the pairs of longitudinal lines of weakness forming the non-right-angled, flat bevelled portions 20 of the longitudinal edges 16 converge at the corners of the major front wall panel 4 and major rear wall panel 6 of the blank 22.
The blank 22 further comprises a pair of lower end wall flaps 24, which are connected to the ends of the first 8 b and second 10 b inner minor side walls panels proximate the lower generally rectangular end wall panel 12 along transverse lines of weakness.
In the blank of FIG. 3, the longitudinal free edges of the outer 8 a, 10 a and inner 8 b, 10 b minor side wall panels of the blank 22 are cut to follow the profile of the lines of weakness forming the minor right-angled portions 18 a and a major, non-right-angled, flat bevelled portions 20 of the four longitudinal edges 18 of the rigid cup pack 2.
FIG. 4 a shows an enlarged perspective view of the upper front corner of the rigid cup pack 2 according to the first embodiment of the invention encircled in broken lines in FIG. 1. FIGS. 4 b and 4 c show corresponding views of the upper corners of rigid cup pack according to second and third embodiments of the invention, respectively.
As in the rigid cup pack 2 according to the first embodiment of the invention, each of the four longitudinal edges of the rigid cup pack according to the second embodiment of the invention includes a pair of opposed minor right-angled portions 18 a and a major, non-right-angled portion 20 disposed between the pair of opposed right-angled portions 18 a. However, as shown in FIG. 4 b, in the rigid cup pack according to the second embodiment of the invention the major non-right-angled portion 20 of each of the longitudinal edges is formed by four generally parallel, straight longitudinal lines of weakness that converge at the ends of the opposed right-angled portions 18 a of the longitudinal edge.
Each of the four longitudinal edges of the rigid cup pack according to the third embodiment of the invention (see FIG. 4 c) also includes a pair of opposed minor right-angled portions 18 a and a major, non-right-angled portion 20 disposed between the pair of opposed right-angled portions 18 a. However, in the rigid cup pack according to the third embodiment of the invention the major non-right-angled portion 20 of each of the longitudinal edges is formed by five generally parallel, straight longitudinal lines of weakness. As shown in FIG. 4 c, four of the five generally parallel, straight longitudinal lines of weakness forming each non-right-angled portion 20 converge at the ends of the opposed right-angled portions 18 of the longitudinal edge. The fifth, central straight longitudinal line of weakness is of reduced length compared to the other four longitudinal lines of weakness, and does not extend to the ends of the opposed right-angled portions 18 a.
FIG. 5 shows a perspective view of a longitudinal edge of a rigid cup pack according to a fourth embodiment of the invention. As in the rigid cup packs according to the first, second and third embodiments of the invention, each of the four longitudinal edges of the rigid cup pack according to the fourth embodiment of the invention includes a pair of opposed minor right-angled portions 18 a and a major, non-right-angled portion 20 disposed between the pair of opposed right-angled portions 18. However, as shown in FIG. 5, in the rigid cup pack according to the fourth embodiment of the invention the major non-right-angled portion 20 of each of the longitudinal edges extends downwardly from the respective adjacent minor side wall 8 of the pack into the respective adjacent major side wall 4 of the pack. This gives the rigid cup pack according to the fourth embodiment of the invention the impression of being twisted counter-clockwise. In an alternative embodiment (not shown), the major non-right-angled portion 20 of each of the longitudinal edges extends downwardly from the respective adjacent major side wall 4 of the pack into the respective adjacent minor side wall 8 of the pack. This gives the rigid-cup pack the impression of being twisted in clockwise.
The rigid cup packs according to the second, third and fourth embodiments of the invention are otherwise of identical construction to the rigid cup pack 2 according to the first embodiment of the invention shown in FIG. 1.
Rigid cup packs according to the invention may advantageously be produced using existing machinery for producing known hinge-lid packs following only minor modifications thereto.
While the invention has been exemplified above with respect to a rigid cup pack, it will be appreciated that packs according to the invention may alternatively be slide and shell packs, booklet packs or any other packs substantially in the form of a generally rectangular parallelepiped known in the art having at least one substantially rectangular open end face.
In this specification the words “generally” and “substantially” are sometimes used with respect to terms. When used with geometric terms, the words “generally” and “substantially” are intended to encompass not only features which meet the strict definitions but also features which fairly approximate the strict definitions. When the word “about” is used in connection with numerical values, it is intended to include not only the recited numerical value but also values within a tolerance of ±10% of the stated numerical value. In this connection, the terms “rounded” and “curved” are intended to also include configurations comprising two or more substantially straight line segments describing the “rounded” or “curved” feature.
Many objects and advantages of the present invention will be apparent to those skilled in the art. Moreover, numerous modifications, variations, substitutions, and equivalents for features of the present invention will be apparent to those skilled in the art. Accordingly, it is expressly intended that all such modification, variations, substitutions, and equivalents that fall within the spirit and scope of the appended claims be embraced thereby.

Claims

1. A pack for smoking articles substantially in the form of a generally rectangular parallelepiped, the pack comprising:

a pair of opposed major side walls;

a pair of opposed minor side walls;

four longitudinal edges between the major and minor side walls; and

a pair of opposed substantially rectangular end faces defined by transverse edges of the major and minor side walls,

wherein at least one of the opposed substantially rectangular end faces is an open end face defined by free transverse edges of the major and minor side walls, at least one of the four longitudinal edges has a non-right-angled portion and the transverse perimeter of the pack is substantially constant.

2. A pack according to claim 1, wherein at least one of the four longitudinal edges has a pair of opposed substantially right-angled portions adjacent the opposed substantially rectangular end faces, and the non-right-angled portion is disposed between the pair of substantially right-angled portions.

3. A pack according to claim 1 wherein at least one of the four longitudinal edges has a non-right-angled, generally flat bevelled portion.

4. A pack according to claim 1, wherein at least one of the four longitudinal edges has a non-right-angled, generally rounded portion of substantially curved transverse cross-section.

5. A pack according to claim 1 formed from a folded blank, wherein at least one of the four longitudinal edges has a non-right-angled portion formed by at least two longitudinal lines of weakness in the blank.

6. A pack according to claim 5 wherein the at least two longitudinal lines of weakness are generally parallel, with one being in a respective adjacent major side wall of the pack and another being in a respective adjacent minor side wall of the pack.

7. A pack according to claim 5 wherein at least one of the four longitudinal edges has a non-right-angled portion formed by at least three longitudinal lines of weakness in the blank.

8. A pack according to claim 1 wherein at least one of the four longitudinal edges has a rounded portion of substantially outwardly convex transverse cross-section.

9. A pack according to claim 1 wherein each of the four longitudinal edges has a non-right-angled portion.