Strengthened carton and method for stacking cartons

Abstract

 The invention which is the subject of this application relates to improvement to a carton and carton blank which allow the strength of the same to be improved and in particular the strength of the side wall for the same to be improved. A double thickness side wall is formed by gluing together the portions (6B). As a result the ability to stack a number of said cartons without using outer packaging is possible and the invention also relates to the stack and the method of forming same.
The cartons in the stack are arranged such that the position of the double layer thickness side wall of the respective cartons do not lie in the same position throughout the stack.

Description

[0001] The invention which is the subject of this application relates to an improved form of carton which allows the strength of the carton to be improved and, furthermore to provide a method and means for stacking the improved form of cartons so as to form a stack or pallet of the cartons which has added strength and allows the need for outer packaging for the pallet or stack to be discarded.

[0002] The invention is of particular, but not exclusive relevance, to a relatively flat form of carton which is used to contain relatively flat foodstuffs such as pizzas , quiche and the like. Indeed any form of carton which has a display face and rear face which are substantially greater in area than the side walls of the carton is particularly suited to the improvement of this invention.

[0003] This type of carton is known in the trade as the end load type of carton and is normally provided to have a display face, rear face and two side walls which, with the exception of a thin portion of one of the side walls where the ends of the carton blank are joined, is formed of card of a single layer thickness. The depth of the portion where the ends of the blank are joined is kept to a minimum in order to minimise the overlap and thereby minimise the usage of the board. The open ends of the carton are sealed once the article is placed into the same by gluing or locking together top, bottom and side flaps in the conventional manner. In practice this form of carton is found to be sufficiently strong when on its own to protect the foodstuff during display and subsequent purchase by a customer. However, when the carton is packaged with a number of other cartons for transport from the place of manufacture to the point of sale it is found that the stack formed by placing the cartons, one on the other, does not have the necessary strength and is susceptible to damage. At present, and in order to overcome this problem, the cartons are stacked and then surrounded with outer packaging in the form of corrugated fibreboard outer and then may be surrounded with plastic sheeting.

[0004] This is known to provide a solution but there are two main problems, one being that the outer are discarded once the goods have been delivered for unpacking and are therefore not used again and represent wasted cost and materials and, secondly there are ever increasing pressures to reduce packaging and this has led to the introduction of a tax being levied on outer packaging of this sort so that the costs are further increased.

[0005] The aim of the present invention is to provide a carton of a form which allows the same to have additional strength and to provide a method of stacking said cartons so that the need for fibreboard outer packaging is removed without unduly affecting the strength of the stack and without causing damage to the same or the products therein.

[0006] In a first aspect of the invention there is provided a carton for containing an article, such as a foodstuff, of a relatively flat shape, said carton comprising a display face and rear face spaced by side walls and said article enclosed within the carton by sealing end flaps to form two end walls and wherein at least one of the side walls of the carton is formed of overlapping portions to form a double layer thickness over substantially all of the side wall.

[0007] The overlapping portions are provided such that the side wall is formed with a double layer over the full extent of the same and, in one embodiment, the free edge of the inner layer of the wall contacts with the inside of the rear or display face to engage with the same.

[0008] In a preferred embodiment the two layers which form the double layer side walls are glued together by a glue stripe along the length so as to provide, in effect, a unitary double layer wall with increased rigidity and which structurally strengthens the carton.

[0009] Typically the side walls of the carton have, depending from each end thereof, side flaps which are folded and joined to the flaps from the display and rear faces to form the end walls. According to a preferred embodiment of the invention the side flaps depending from the double layer side wall are also formed with a double layer thereby adding to the strength of the end walls when formed.

[0010] In a further aspect of the invention there is provided a carton for containing an article, such as a foodstuff, of a relatively flat shape, said carton comprising a display face and rear face, spaced by side walls and said article enclosed within the carton by sealing end flaps to form two end walls and characterised in that the carton is formed by sealing an overlapping portion to a portion of the carton blank which forms one of the side walls and said overlapping portion is formed so that at least a portion of the same extends across substantially the width of the side wall portion.

[0011] In one embodiment the overlapping portion contacts with the inner surface of the rear or display face of the carton. In one arrangement the overlapping portion engages with the engagement means formed in the side wall and/or rear or display faces. Thus it will be appreciated that the portion of the overlapping portion which extends across the width of the side wall layer need not extend across the entire length of the side wall but may be provided to do so at one or a number of areas along the length of the side wall to suit specific requirement and, if possible save on material usage.

[0012] In a further aspect of the invention there is provided a stack or pallet formed of a plurality of cartons, each carton having a display face, rear face and side walls and containing an article therein, said article of generally flat form and enclosed by closing and sealing end flaps to form two end walls and wherein at least a proportion of the cartons in the stack have at least one side wall which is formed of overlapping portions of the carton material to form a double layer thickness over substantially all of the side wall.

[0013] Preferably all of the cartons in the stack have a side wall which is of double layer thickness and so the stack thus formed has sufficient strength so as to allow the need for outer packaging to surround the stack to be removed.

[0014] In one embodiment of the invention the cartons in the stack can be arranged such that the position of the double layer thickness side wall of the respective cartons do not lie in the same position throughout the stack. Preferably however the cartons are arranged such that the cartons in successive layers are located such that the double layer thickness side walls lie to the outside of the stack thereby providing the stack with a relatively strong outer face to prevent the stack, cartons and contents being damaged during the application of the plastics shrink-wrap material around the stack when formed and without the board outer material.

[0015] In a yet further aspect of the invention there is provided a method for packaging and transporting a number of foodstuff articles, said method comprising forming a plurality of cartons with a side wall in each carton having a double layer thickness, inserting the article or articles into the cartons and sealing the same by closing the carton openings and stacking the cartons such that in the first layer the double thickness side wall of each carton in that layer is provided at a particular orientation and then in the next layer the orientation of the double thickness side wall of each carton can be altered with respect to the double thickness side wall of the carton below and so on in successive layers until the stack is formed and the double thickness side wall of those cartons which are positioned adjacent the outside of the stack lie to form part of the outer wall of the stack.

[0016] It has therefore been found that by increasing the strength of the carton side wall by providing it with a double layer so the need for the fibreboard outer packaging is removed and the savings to the manufacturer are far greater than the extra cost for the additional material required to form the double thickness side wall.

[0017] Specific embodiments of the invention will now be described with reference to the accompanying drawings wherein;

Figure 1 illustrates the carton blank according to the invention;

Figure 2 illustrates the carton blank in erected form,

Figure 3 illustrates a cross sectional view along line AA of Figure 2;

Figure 4 illustrates a stack of cartons according to the invention;

Figure 5 illustrates a cross section along line B-B in schematic fashion for illustrative purposes;

Figure 6 illustrates a plan of a further embodiment of a carton according to the invention; and

Figure 7 illustrates a further alternative embodiment of a carton according to the invention.

[0018] Referring firstly to Figures 1-3 there is shown a carton according to the invention. In Figure 1 there is shown a carton blank which comprises a display face 2, a rear face 4, side wall portions 6A and 6B and end wall flaps 8.

[0019] Typically the carton is partially erected before being sent to the manufacturer of the product to be held in the carton and this partial erection comprises gluing together the side wall portions 6B to form the second side wall. As shown in this embodiment the side wall formed is of double layer thickness as both of the portions 6B are formed of equal depth X and of a depth which matches the required height Y of the side wall. Thus one of the side walls of the carton is provided to have double thickness and rigidity.

[0020] The cartons are then sent to the manufacturer of the article in a flattened partially erected form whereupon the manufacturer moves the cartons to an upstanding position, inserts the article through the open end walls and once the article is inserted, the end flaps 8 are sealed together with the side wall end flaps 8' folded inwardly first and then enclosed by the display and rear face end flaps 8 to form a sealed carton.

[0021] Thus the carton formed which has the double thickness side wall formed by gluing together the portions 6B along the depth of the wall has significantly greater rigidity than conventional cartons and, furthermore, considerably greater strength so that, in combination, a plurality of the cartons can be stacked without the need for outer packaging and with a minimised risk of damage to the article in the cartons. It should however be appreciated that in other embodiments of the invention one of the portions 6B can be shaped, and example of which is illustrated in Figure 7, so that not all of the same extends across the width of the other side wall portion 6B but rather the same is shaped so that one, or a number of areas 9 at spaced intervals, of the portion 6B are formed to extend across the width of the other side wall portion 6B to provide the double layer thickness of side wall at at least these areas and a combined side wall of the required strength. This shaping of one of the portions 6B which is typically that which lies to the inside of the erected carton, can be provided to ensure the required strength and also minimise material usage.

[0022] In any embodiment the edges of the portions or one of the portions 6B which form the side wall, can be provided to contact the rear or display face inner surface or even be arranged to engage with engagement means provided in the carton to further secure same.

[0023] A stack of cartons 10 manufactured according to the invention is shown in Figure 4 and this type of stack is formed by the manufacturer once the cartons are sealed and ready to be transported to the point of sale on a pallet 12. Conventionally, at this stage outer packaging is wrapped around the cartons to prevent damage and provide added strength to the same before the same are wrapped in a protective plastics sheeting. However by using the cartons according to the invention the need for the outer packaging is overcome and the same can then simply be surrounded with plastic sheeting if required.

[0024] Figure 5 illustrates a schematic sectional view along line B-B of one layer of cartons and illustrates how in one embodiment the double thickness side wall formed by the portions 6B of each of the cartons is arranged in that layer. Also shown in broken lines is the arrangement of the double thickness side wall 6B' of each of the cartons in the layer below and it will be seen that the cartons in this embodiment are orientated so as to spread the effect of the strengthened double thickness side wall but in each case that the double thickness side wall lies to the outside of the stack so as to form part of the outer wall of the stack with added strength and thereby provide overall increased strength. This is repeated with all of the layers of the stack so that when the shrink-wrap plastics material is applied around the stack, the cartons and contents are not damaged due to the location of the stronger side walls of the cartons at the outer walls of the stack.

[0025] Figure 6 illustrates a further embodiment of a carton blank according to the invention and this blank is similar to that of the preceding figures 1-3 with the exception that the end flaps 108' extend from only one of the side wall portions 106B so that when the portions 106B are brought together the end flaps 108' are of single layer thickness. Other than this however, the carton is of similar form to that shown in the preceding figures.

[0026] Thus it is submitted that the carton and the method of stacking the same for transport with other cartons represent a significant improvement over the prior art cartons and methods which allow significant cost savings to be achieved while at least maintaining the condition of the cartons in comparison with conventional methods.

Claims

1. A carton for containing an article, such as a foodstuff, of a relatively flat shape, said carton comprising a display face and rear face, spaced by side walls and said article enclosed within the carton by sealing end flaps to form two end walls and characterised in that at least one of the side walls of the carton is formed of overlapping portions to form a double layer thickness over substantially all of the side wall.

2. A carton according to Claim 1 characterised in that the overlapping portions are provided such that the side wall is formed with a double layer over the full extent of the same.

3. A carton according to Claim 2 characterised in that the free edge of the inner layer of the double layer side wall contacts with the inside surface of the rear or display face to locate with the same.

4. A carton according to Claim 1 characterised in that the two layers which form the substantially double layer side wall are glued together to form a unitary double layer wall.

5. A carton according to Claim 1, characterised in that the side walls of the carton have, depending from each end thereof, side wall end flaps which are folded and joined to the flaps from the display and rear faces to form the end walls.

6. A carton according to Claim 5 characterised in that the side wall end flaps depending from the double layer side wall are also formed with a double layer thickness thereby adding to the strength of the end walls when formed.

7. A carton for containing an article, such as a foodstuff, of a relatively flat shape, said carton comprising a display face and rear face, spaced by side walls and said article enclosed within the carton by sealing end flaps to form two end walls and characterised in that the carton is formed by sealing an overlapping portion to a portion of the carton blank which forms one of the side walls and said overlapping portion is formed so that at least a portion of the same extends across substantially the width of the side wall portion.

8. A carton according to claim 7 characterised in that the overlapping portion contacts with the inner surface of the rear or display face of the carton.

9. A carton according to claim 8 characterised in that the overlapping portion engages with the engagement means formed in the side wall and/or rear or display faces.

10. A blank for the erection of a carton for containing an article therein, said blank comprising front face, rear face and side wall portions and flaps or portions to allow the formation of a further side wall, and two end walls by attaching respective flaps together and characterised in that the first and second flaps for forming said side wall are dimensioned such that when the same are brought together for attachment the same overlap and at least a portion of a first flap extends across the width of the second flap to form a double layer side wall at least over the area of the said portion.

11. A blank according to claim 10 characterised in that the first flap is formed so that said flap extends across the width of the said second flap substantially along the length thereof.

12. A stack or pallet formed of a plurality of cartons, each carton having a display face, rear face and side walls, and containing an article therein, said article of generally flat form, and enclosed by enclosing and sealing end flaps to form two end walls and characterised in that at least a proportion of the cartons in the stack have at least one side wall which is formed of overlapping portions of the carton material to form a double layer thickness over substantially all of the side wall.

13. A stack or pallet of cartons according to Claim 12 characterised in that all of the cartons in the stack have a side wall which is of double layer thickness and so the stack thus formed has sufficient strength to allow the need for outer packaging to surround the stack to be removed.

14. A stack of cartons according to Claim 12 characterised in that the cartons in the stack are arranged such that the position of the double layer thickness side wall of the respective cartons do not lie in the same position throughout the stack.

15. A stack of cartons according to Claim 14 characterised in that the cartons are arranged so that the cartons successive layers are located with a double layer thickness side walls lying to the outside of the stack to provide the stack with a relatively strong outer face.

16. A method for packaging and transporting a number of foodstuff articles, said method comprising formerly a plurality of cartons with a side wall of each carton having substantially double layer thickness, inserting the article or articles into the cartons and sealing the same by closing the carton openings and stacking the cartons such that in the first layer the double thickness side wall of each carton in that layer is provided at a particular orientation and then in the next layer the orientation with the double thickness side wall of each carton is altered with respect to the double thickness side wall of the carton below and so on in successive layers until the stack is formed and the double thickness side walls of those cartons which are positioned adjacent the outside of the stack lie to form part of the outer wall of the stack.

Drawing