It is known to package liquid, for example milk or orange juice, by initially supplying a rolled web of substrate, for example paperboard coated on both faces with one or more plastics layers, particularly with liquid barrier plastics, for example low density polyethylene (LDPE), as the two exposed layers. The web can be supplied to a converting plant where the intended outermost surface for the carton is printed and the printed web is then cut into blanks, which are then supplied to a packaging plant where, on a form-fill- seal packaging machine, the blanks are formed into open- topped cartons, filled and then top-sealed. Instead of the web being supplied to a converting plant, it can be supplied in a printed state to a form-fill-seal machine in which the web is formed into a tube to which the liquid is continually supplied and the tube continually cross-sealed and cartons produced by continually severing the tube at the cross-seals.

EP-A-540923 discloses a carton which is particularly for pulverulent or granular contents and of which a top wall is formed with a pouring opening closed by a barrier foil which can be removed from the opening to permit pouring but which meanwhile prevents deterioration of the contents owing to the opening in the wall of the carton. The carton material can be paperboard coated on both faces with linear polyethylene.

US-A-4771891 discloses a carton for granular contents, for example a cereal, of which the side wall is formed with a U-shaped perforation covered by a label firmly attached to the side wall at locations above and below the U-shaped perforation and to the rectangular wall portion bounded by the perforation. Over a U-shaped zone embracing the perforation the label is only weakly attached to the wall.

Immediately below the U-shaped zone the label is free from the side wall and includes a horizontal tear strip. To open the carton, the tear strip is torn away and the label lifted and pulled to release the weakly attached, U-shaped zone of the label from the side wall and to break the perforation and to pull outwardly and upwardly the portion bounded by the

perforation. If necessary, after the label has been raised to the perforation, additional mechanical force, such as the application of a knife blade or a fingernail, may be employed to assist in initially starting the opening of the portion bounded by the perforation.

US-A-5002222 discloses a carton for powdered detergents in which the carton blank was formed with a U-shaped die cut impressed into mainly a side wall of the carton but partly in an adjacent top wall, the die cut in the blank then being covered with tape means adhered releasably to the wall portions outside the die cut and adhered firmly to the wall portion inside the die cut, so that, upon pulling outwards and upwards of the tape means, the wall portion inside the die cut is displaced outwards and upwards to provide a pouring opening in the side wall.

According to one aspect of the present invention, there is provided a carton comprising a wall, a loop of weakness in said wall and extending around a portion of said wall, and a member attached to and extending over said portion and seizable by a consumer and pullable to pull said portion out of the plane of the wall to provide an opening through said wall, characterized in that said carton has indicating means arranged to indicate to a consumer where to apply a digit to press inwardly said portion to break said loop of weakness around said portion.

According to another aspect of the present invention, there is provided a method of opening a carton comprising seizing and pulling outwardly a member attached to a portion of a wall of said carton and thereby pulling said portion out of the plane of the wall to provide an opening through the wall, characterized in that said pulling is preceded by pressing said portion inwardly to break a loop of weakness around said portion.

Owing to these aspects of the invention, it is possible to open reliably a carton which has a relatively inexpensive opening arrangement which is simple to operate.

According to a further aspect of the invention, there is provided a container comprising a wall, a loop of weakness in

perforation. If necessary, after the label has been raised to the perforation, additional mechanical force, such as the application of a knife blade or a fingernail, may be employed to assist in initially starting the opening of the portion bounded by the perforation.

US-A-5002222 discloses a carton for powdered detergents in which the carton blank was formed with a U-shaped die cut impressed into mainly a side wall of the carton but partly in an adjacent top wall, the die cut in the blank then being covered with tape means adhered releasably to the wall portions outside the die cut and adhered firmly to the wall portion inside the die cut, so that, upon pulling outwards and upwards of the tape means, the wall portion inside the die cut is displaced outwards and upwards to provide a pouring opening in the side wall.

According to one aspect of the present invention, there is provided a carton comprising a wall, a loop of weakness in said wall and extending around a portion of said wall, and a member attached to and extending over said portion and seizable by a consumer and pullable to pull said portion out of the plane of the wall to provide an opening through said wall, characterized in that said carton has indicating means arranged to indicate to a consumer where to apply a digit to press inwardly said portion to break said loop of weakness around said portion.

According to another aspect of the present invention, there is provided a method of opening a carton comprising seizing and pulling outwardly a member attached to a portion of a wall of said carton and thereby pulling said portion out of the plane of the wall to provide an opening through the wall, characterized in that said pulling is preceded by pressing said portion inwardly to break a loop of weakness around said portion.

Owing to these aspects of the invention, it is possible to open reliably a carton which has a relatively inexpensive opening arrangement which is simple to operate.

According to a further aspect of the invention, there is provided a container comprising a wall, a loop of weakness in

said wall and extending around a portion of said wall, and a member attached to and extending over said portion and seizable by a consumer and pullable to pull said portion out of the plane of the wall to provide an opening through said wall, characterized in that said container contains liquid and in that said loop of weakness does not perforate said wall. o Owing to this aspect of the invention, it is possible to package liquid in a carton which has a relatively inexpensive opening arrangement which is simple to operate.

The carton may be a flat-topped carton with a fin seal extending down respective opposite sides of the carton, or a gable-topped carton, or a flattened gable-topped carton. The loop of weakness may be an open loop, whereby the opened portion remains integral with the wall, or may be a closed loop, whereby the wall portion may be completely removed from the wall. The opening member is preferably elongate and advantageously consists of sheet material which extends face- to-face over the wall portion.

In the event that the line of weakness is a closed loop, the opening member advantageously remains attached to a part of the wall other than the portion in question, so that the portion remains connected to the carton and does not constitute litter.

In order that the invention may be clearly and completely disclosed, reference will now be made, by way of example, to the accompanying drawings, in which:- Figure 1 is a fragmentary front elevation of a carton with a flattened gable top and a first version of an opening strip, Figure 2 is a top plan view of the carton of Figure 1, Figure 3 is a fragmentary plan view of part of a row of opening strips of a second version of strip, Figure 4 is a view similar to Figure 1, but of the carton with the second version of strip, and Figure 5 is a view similar to Figure 2 of the carton.

Referring to Figures 1 and 2, the carton 2 has a wall comprised of paperboard as a stiffening layer and inside and

said wall and extending around a portion of said wall, and a member attached to and extending over said portion and seizable by a consumer and pullable to pull said portion out of the plane of the wall to provide an opening through said wall, characterized in that said container contains liquid and in that said loop of weakness does not perforate said wall. o Owing to this aspect of the invention, it is possible to package liquid in a carton which has a relatively inexpensive opening arrangement which is simple to operate.

The carton may be a flat-topped carton with a fin seal extending down respective opposite sides of the carton, or a gable-topped carton, or a flattened gable-topped carton. The loop of weakness may be an open loop, whereby the opened portion remains integral with the wall, or may be a closed loop, whereby the wall portion may be completely removed from the wall. The opening member is preferably elongate and advantageously consists of sheet material which extends face- to-face over the wall portion.

In the event that the line of weakness is a closed loop, the opening member advantageously remains attached to a part of the wall other than the portion in question, so that the portion remains connected to the carton and does not constitute litter.

In order that the invention may be clearly and completely disclosed, reference will now be made, by way of example, to the accompanying drawings, in which:- Figure 1 is a fragmentary front elevation of a carton with a flattened gable top and a first version of an opening strip, Figure 2 is a top plan view of the carton of Figure 1, Figure 3 is a fragmentary plan view of part of a row of opening strips of a second version of strip, Figure 4 is a view similar to Figure 1, but of the carton with the second version of strip, and Figure 5 is a view similar to Figure 2 of the carton.

Referring to Figures 1 and 2, the carton 2 has a wall comprised of paperboard as a stiffening layer and inside and

outside layers of thermoplastics, for example low density polyethylene, as moisture barrier layers, possibly with the interposition of an oxygen barrier layer, for example aluminium or ethylene vinyl alcohol, between the paperboard layer and the inside thermoplastics layer. The carton 2 has a front panel 4, a rear panel 6, two side panels 8 and 10, two top closure panels 12 and 14, bottom closure panels (not seen), and a top sealing fin 16 which may be releasably tacked to the panel 14. The flattened gable ends of the top closure are not seen. The panel 12 is formed, in the outside surface thereof, with a closed loop of weakness 18 in the form of a partial depth die cut. The die cut is formed when the carton blank from which the carton 2 will be made is being formed with score lines before the blank is cut out.

Extending horizontally over the panel 12 and vertically down the panel 4 is an opening strip 20 which has been applied to those panels either before filling of the open-topped carton on a form-fill-seal packaging machine or after top-sealing of the filled carton on the machine. Towards its lower end, the strip 20 converges towards a widened end portion 22 thereof.

Its other end portion 24, an intermediate portion 26 thereof and the end portion 22 are attached, either by heat-and pressure-sealing, or by hot melt, 28,30 and 32, respectively, to the external surface of the wall of the carton 2. The intermediate portion 26 is attached to that portion 34 of the panel 12 surrounded by the die-cut 18. The end portion 24 is attached to that part of the panel 12 between the fin 16 and the portion 34. The end portion 22 is attached to the panel 4. Formed across the opening strip 20 at its narrowest portion is a perforation 36. Formed across the strip 20 between the portions 24 and 26 thereof is a score line 38. A cross-hatched zone 40 of the intermediate portion 26 above the wall portion 34 indicates where a consumer would be instructed to press downwards on the intermediate portion 26 to open the carton. Between the zone 40 and that edge of the die-cut 18 nearest the front panel 4 is a score line 42 formed across the strip 20.

To open the carton, the consumer pulls outwards the zone

of the strip 20 immediately above the anchored end portion 22, so breaking the strip 20 at the perforation 36. The consumer then presses downwards at the zone 40, so fracturing along at least part of the die-cut 18, the score line 42 permitting the two parts of the strip 20 at respective opposite sides thereof to fold easily relatively to each other. Then the consumer seizes the foremost of those two parts and swings it upwardly about the score line 38 in order to fracture totally along the die-cut 18 and to remove the portion 34 from the panel 12. The strip 20 and thus the portion 34 remain attached to the carton wall by way of the end portion 24. With the portion 34 held fully open by way of the strip 20, the contents of the carton 2 can be poured out through the opening thus provided in the panel 12.

Figure 3 illustrates in full lines two of a row of opening strips 20 of a version in which there is no need to break a perforation 36 and in which the strips 20 can readily be supplied as a band 50 wherein they are readily separable from each other at narrow outer and intermediate junctions 52,54 and 56 as they are applied to respective cartons 2.

Referring to Figures 4 and 5, the end part 22 of the strip 20 is elongate transversely of the strip 20 so as to form two lobes, one lobe 58 of which is sealed to the front panel 4 by heat-and pressure-sealing, or by hot melt 59, and the other lobe 60 of which remains free, so that the consumer can seize the free lobe 60 and pull it forwards to detach the strip 20 from the anchorage at 58 and then, after pressing inwards at the indication 40 to break the loop of weakness 18, swing the forward part of the strip up and over the top of the carton 2. The strip 20 includes an opposite end part 20a attached to a portion of the panel 12 at the opposite side of the die-cut 18 from the panel 4, a part 20b attached to the portion 34, and a part 20c at the edge between the panels 4 and 12. The parts 20a and 20c are of the same width as each other and wider than the part 20b and than the loop of weakness 18. The part 20b is narrower than the loop of weakness 18. By such appropriate dimensioning of the widths of the loop of weakness 18 and the parts 20a to 20c, it is

of the strip 20 immediately above the anchored end portion 22, so breaking the strip 20 at the perforation 36. The consumer then presses downwards at the zone 40, so fracturing along at least part of the die-cut 18, the score line 42 permitting the two parts of the strip 20 at respective opposite sides thereof to fold easily relatively to each other. Then the consumer seizes the foremost of those two parts and swings it upwardly about the score line 38 in order to fracture totally along the die-cut 18 and to remove the portion 34 from the panel 12. The strip 20 and thus the portion 34 remain attached to the carton wall by way of the end portion 24. With the portion 34 held fully open by way of the strip 20, the contents of the carton 2 can be poured out through the opening thus provided in the panel 12.

Figure 3 illustrates in full lines two of a row of opening strips 20 of a version in which there is no need to break a perforation 36 and in which the strips 20 can readily be supplied as a band 50 wherein they are readily separable from each other at narrow outer and intermediate junctions 52,54 and 56 as they are applied to respective cartons 2.

Referring to Figures 4 and 5, the end part 22 of the strip 20 is elongate transversely of the strip 20 so as to form two lobes, one lobe 58 of which is sealed to the front panel 4 by heat-and pressure-sealing, or by hot melt 59, and the other lobe 60 of which remains free, so that the consumer can seize the free lobe 60 and pull it forwards to detach the strip 20 from the anchorage at 58 and then, after pressing inwards at the indication 40 to break the loop of weakness 18, swing the forward part of the strip up and over the top of the carton 2. The strip 20 includes an opposite end part 20a attached to a portion of the panel 12 at the opposite side of the die-cut 18 from the panel 4, a part 20b attached to the portion 34, and a part 20c at the edge between the panels 4 and 12. The parts 20a and 20c are of the same width as each other and wider than the part 20b and than the loop of weakness 18. The part 20b is narrower than the loop of weakness 18. By such appropriate dimensioning of the widths of the loop of weakness 18 and the parts 20a to 20c, it is

possible to prevent the strip 20 from being pressed almost totally through the pouring opening whilst still permitting sufficient inward movement of the part 20b by the consumer's digit applied to the zone 40 that the loop of weakness 18 will be virtually fully broken, which is important to prevent failure to reveal the pouring opening upon pulling of the strip 20. The pressing force required to break the loop of weakness 18 is between about 20N and about 40N. A force requirement below about 20N risks inadvertent breaking of the loop of weakness, whilst a force requirement above about 40N would render it difficult for a weak consumer to break the loop of weakness.