The present invention refers to a cardboard container for solid, granular or eventually fluid products, in particular cream or paste products and the like, and to a relative production method.
Although reference will be made in the description that follows mainly to a cardboard container, it is to be understood that the material used to form the container can be a multi-layer material, including a layer of cardboard, able to give a certain stiffness to the container, and any other layers of sheet material.
Containers of the type to which the invention refers are normally common cardboard boxes, obtained by successive folding and gluing of a flat blank, so as to obtain a substantially parallelepiped shape of the desired size.
Obviously, besides the classic parallelepiped shape, other shapes have been suggested according to the particular use for which the container is intended.
Cardboard containers of the box type have various drawbacks, which range from the fact that the container does not have a perfect seal to the fact that it cannot be re-closed or that the re-closure of the container is not practical in the event of partial use of the product, to the fact that a loss of or a decrease in stiffness of the container occurs if opening thereof involves essentially the entire upper face.
Also, such box-shaped cardboard containers do not lend themselves to contain viscous, pasty or fluid products.
European patent application No. 03011600.8 of 22.05.03, not yet published, in the name of the same applicant, describes a container whose body and whose upper closing wall are obtained from two separate blanks. The present invention is intended to improve and to simplify the structure of the container described in said European patent application.
In particular, an object of the invention is to provide a cardboard container that is perfectly sealed before use and which can be opened easily to form a large opening for removing the product, which involves essentially the entire upper face of the container.
Another object of the invention is to provide a container which maintains a good stiffness even after opening.
Yet another object of the invention is to provide a container which, in a suitable composition of various components, can be produced in a completely hermetic form, so as to be suitable for containing products in a pasty, viscous or fluid state.
Another, but not last, object of the invention is to provide such a container that is simple and economical to produce.
The container according to the invention has the characteristics of appended independent claim 1.
Advantageous embodiments of the invention are apparent from the dependent claims.
Essentially, the container according to the invention is obtained from a single blank. In particular, the blank of the body of the container has bend and crease lines, which make the container assume a slightly truncated conical shape, once it is raised, said shape starting from a rectangular base and ending in an octagonal open top wall, widened with respect to the base.
The body of the open container thus produced has, at its upper edge, a series of tongues or flaps which, after the container has been filled with the product, are folded inward to embrace corresponding flaps of the part of the blank forming the upper closing wall of the container.
A pre-cut line is provided in said upper closing wall, to facilitate opening of the container.
The part of the blank forming the container advantageously has at one of its edges an octagonal extension, designed to form a re-closing lid for the container.
The container thus formed, in one embodiment thereof, can be made hermetic, to contain products in a pasty or viscous state, such as yoghurt or the like, and also fluid products.
For this purpose, on the part of the blank designed to form the container body, on the face designed to form the inner surface of the container, there is applied a sheet of plastic material such that, after folding of the blank to form the body of the container, it covers the whole inner surface thereof making it hermetic.
Likewise, the part of the blank forming the upper closing wall of the container has on the inside a thin sheet of aluminium which ensures the upper seal of the closed container and allows easy tearing thereof.
Further characteristics of the invention will be made clearer by the detailed description that follows, referring to purely exemplifying and therefore non-limiting embodiments thereof, illustrated in the appended drawings, in which:
With reference to these figures, and for now in particular to
In a first embodiment, which will now be described, the container 1 is destined particularly to contain solid, granular or even powder products. Sweets, chocolates, animal foods, detergents and the like are cited purely by way of example as products for which the container is intended.
As can be seen in
In particular, the octagonal upper edge 3 of the container has four larger-sized sides 4, opposed two by two and corresponding to the four side walls 5 of the container, separated by the same number of smaller-sized sides 6, disposed at the four corners of the container and obtained by means of respective triangular blunting 7 of said corners, which start from zero at the base 2 of the container and reach their greatest width at the top thereof.
As can be seen better in
With reference now to FIGS. 3 to 5, the elements composing the container 1 according to the invention, and the manner in which it is produced are described.
The container 1 is obtained essentially from a single blank 100, shown in a plan view in
a central portion 10 designed to form the body of the container, shown in the upright position in
a first octagonal end portion 11 designed to form the top closing wall 8 of the container, shown in
a second octagonal end portion g designed to form the re-closing lid 9, also shown in the open position in
In said figures, the dashed lines indicate crease and bend lines, along which the various parts of the blank are folded to obtain the container, as will now be better described.
The blank 100 of
Corresponding tongues b, which are folded inward by about 90° during formation of the container are attached, by respective bend lines 12, to the two smaller sides of the rectangle a.
Attached by respective bend lines (13, 13′) to the other two sides of the rectangle a are trapezoidal portions (c, c′), having their larger bases at said lines (13, 13′), destined to form the rear wall and the front wall of the container 1, respectively, as shown in
In
Joined to the sides of the trapezoidal portions (c, c′), by means of crease lines (14, 14′), there are respective pairs of triangular portions (d, d′), with their vertices disposed at the vertices of the central rectangle a, said triangular portions (d, d′) being able to form said blunted corners 7 of the container 1.
Joined to the triangular portions (d, d′), again along crease lines (15, 15′), there are further substantially rectangular trapezium shaped portions (e, e′), with the acute angles of the trapeziums facing toward the central rectangular portion a.
The trapezoidal portions or wings e are narrower than the corresponding wings e′ and are destined to be disposed on the inside thereof, to form together the two side walls, right and left, of the container 1. On the outer edge of the wings e′ there are provided respective strips of glue 16, to block the superimposed wings (e, e′) firmly, possibly also by heat-sealing.
Trapezoidal flaps (f, f′) protrude from the upper and lower edges of the triangular portions d and d′, respectively. A trapezoidal flap f1′ protrudes from the lower edge of one of the trapezoidal portions e′, whilst a connecting flap f4′ protrudes from the other portion e′. A trapezoidal connecting flap f3 protrudes from the upper edge (lesser base) of the trapezoidal portion c, whereas two trapezoidal flaps f2′, spaced apart, protrude from the lower edge of the trapezoidal portion c′.
The connecting flap f4′ is destined to be folded toward the inside of the container along the bend line 17′ to lower the top closing wall 8 inside the body of the container. On the other hand the end flaps f, f′, f1′ and f2′ and the connecting flap f3 are destined to be folded to the inside of the container along the respective bend lines (17, 17′) to block the top closing wall 8 of the container, as will be better explained later.
Furthermore, the first octagonal portion 11 of the blank destined to form the top closing wall 8 of the container is connected by means of a bend line 18 to the connecting flap f4′ of the trapezoidal portion e′. On the other hand, the second octagonal portion g of the blank, destined to form the re-closing lid 9 of the container and provided with a pull tab 20 that can oscillate around a bend line 19, is connected by means of a bend line 18 to the connecting flap f3 of the trapezoidal portion c.
The potion 11 of the blank is octagonal in shape in a plan view, as described above, and has seven rectangular flaps h, connected by means of respective bend lines 21 to seven sides of the octagon. The eighth side of the octagon is formed by the bend line 18′ which connects the portion 11 of the blank to the connecting flap f4′ which is of the same size as the larger flaps h. The smaller flap h which coincides with the flap f′ is partially cut. The flap f′ coinciding with the flap h is also cut.
Said flaps h are destined to be folded at about 90° and to be disposed beneath the flaps (f, f3, f′, f1′, f2′) of the part 10 of the blank for closing of the container, as will be better described later.
As can be seen in
Formation of the container 1 starting from the blank 100 of
Starting from the blank 100 and keeping the base a fixed, the two side tongues b are raised, disposing them on the inside, and then the trapezoidal portions (c, c′) are raised together with the other portions (d, e) and (d′, e′) connected thereto. The latter are then rotated around the respective crease and bend lines (14, 15, 14′, 15′), so that the wings e′ partially overlap the corresponding wings e, forming the raised container, open at the top, shown in
During formation of the container, the eight creases (14, 15, 14′, 15′), diverging from the bottom upwards, give rise to the conicity of the container and give its top the aforementioned octagonal shape.
The body of the container can easily be raised mechanically, by means of an internal mandrel which keeps fixed the base a, on which mechanical hinged systems raise the various portions of the part 10 of the blank to form the body of the container.
The open container shown in
The peripheral flaps h of the portion 11 of the blank are folded upwards by about 90°, to take on a tray configuration 25. It is clear that this operation, for the sake of simplicity, can be performed before the body of the container is formed.
The tray-shaped part 25 of the blank is folded along the bend lines (17′, 18) so as to be inserted in the open container of
In this manner, by folding the flaps f, f′ f1′, f2′ and f3 inward onto the corresponding flaps h, after application of a layer of glue, upper sealing of the container is achieved, as shown in
Lastly, the lid 9 is lowered onto the top-closing wall 8, as shown in
It should be noted that in this lowered position, as shown in the sectional view of
Raising of the lid 9 is facilitated by the pull tab 20 which is housed in the empty space determined by said pair of flaps f2′ and which protrudes slightly beyond the top profile of the container 1.
The first opening of the container is facilitated by said pre-cut line 22 formed on the upper closing wall 8.
In fact, by exerting a pressure downwards with a finger on the semi-spherical part 24 in front of the crescent-shaped join 23 of the cut 22, an opening is formed through with it is possible to grip the disk 8′ and to remove it easily by simply pulling upwards, causing detachment along the cut line 22.
It should be noted that the cut line (22-23) can take a path different to that shown by way of example in the appended drawings. In theory it could extend exactly along the inner perimeter of the container.
In practice, however, it is preferred that the disk 8′ leaves, when removed, a rim 30 suitably joined in the corners, which allows the upper mouth of the container to be stiffened.
The function of this rim 30 is also to act as a stop for the re-closing lid 9, which comes to rest thereon after the disk 8′ has been removed.
As shown diagrammatically in
Re-closure of the lid 9 takes place by lowering thereof, as previously described.
In
According to said embodiment, a lining film 40 of single- or multi-layer plastic material, preferably heat sealed on both faces, is applied to the blank part 10.
The film 40 is substantially rectangular in shape, possibly rounded at the two ends, of such a size that its length reaches to the bend lines (17, 17′) of the flaps (f, f3, f′, f1′, f2′, f4)′ whilst its width is such as to allow said film, in the established conicity of the container, to be overlapped to form the tight seal by means of heat sealing.
As shown diagrammatically in
Obviously the arrangement of the above mentioned areas of gluing or heat sealing (41, 42, 42′) is purely exemplary.
A typical structure of the lining film can be PE/PET/PE, in which the PET film acts as heat resistant material, giving a certain stiffness, whilst the two PE films form the part that can be heat sealed on both faces. The PET film can be metallized to give greater impermeability.
The body of the container is formed as described in the previous embodiment, obtaining a container open at the top with an inner lining 40, which can be filled with the product and closed with a lid g, which must also have impermeable characteristics, and a the same time must allow an easy opening along the above mentioned cut line 22.
For this purpose, as shown diagrammatically in
In this manner, when the flaps h are folded to be inserted beneath the corresponding flaps (f, f3, f′, f1′, f2′) of the container, a shaped surface without breaks in continuity is formed.
Fixing of the closing wall 8 to the body of the container takes place as in the preceding embodiment, by sealing the flaps f, f3, f′, f1′ and f2′, heat sealable on the inside to the underlying flaps h and, in this case, also by sealing the aluminium layer 50 to the underlying lining film 40 so as to form a single hermetically sealed whole. The lining film 40 in turn is sealed to the inside part of the container with the dual function of further stiffening of the mouth of the container.
To open the container it is sufficient, as in the previous case, to exert a simple pressure on the semi spherical portion 24 to cause yielding and breaking of the carton along the cut line 22, and thus allow the removal of the disk 8′. In this phase, the thin layer of aluminium 50 faithfully follows the break along the cut line 22.
However, when this heat-sealing operation is performed, the aluminium sheet 50 dilates through the effect of heat, so that creases are formed which compromise sealability in said areas. These creases also form channels which allow air to enter, in the long run causing oxidation and gradual detachment of the aluminium sheet 50 from the polyethylene layer deposited on the cardboard through heat-sealing of the aluminium sheet 50.
To eliminate these phenomena in the octagonal portion 11 of the blank a barrier structure other than the simple aluminium sheet 50 has been designed. As shown in
The paper 72 is of the pelure type and has considerable heat stability, whilst the aluminium film 71 is held by said paper, eliminating the aforementioned creases.
The aluminium film 71, so thin, can be varnished on one side (the outward facing one) to prevent oxidation. The paper 72, on the other hand, being of low grammage, can easily tear under pressure. In the membrane 70, the aluminium film 71 is necessary because it is one of the best barrier materials.
To fix the membrane 70, a layer of polyethylene is applied to the portion 11 of the blank, then the aluminium film 71 or the sheet of paper 72 is heat sealed to the layer of polyethylene, so that one of the two remains on the outside. This solution, furthermore, is possible in that the two materials, that is the aluminium 71 and the paper 72, are varnished with respective layers 73, 74, so that they can come into direct contact inside the container with the product contained therein, as in the case of food products.
It is clear that the membrane 70 can be applied with the thin paper sheet 72 in contact with the portion 11 of the blank so that the aluminium layer 71 remains on the outside.
In this case also, when the top wall 8 of the container is to be opened, the disk 8′ is lowered by applying a pressure to the round part 24 and by breaking the cut lines 22 and 23. As a result the membrane 70, being thin, tears along the cut lines 22 and 23.
It can thus be seen that the blank 100 of
The hermetic container according to the invention also lends itself to an easy re-cycling, in that the lining film 40 of plastic material may be detached from the cardboard blank 10, allowing a separate waste collection. In order to facilitate this operation, a U-shaped pre-cut 60 which defines an openable window m is made in one of the trapezoidal walls c. A crosswise bend line 61 which passes through the bottom part of the window m is provided. In this case the user, after having used the content of the container, lowers the window m toward the inside causing the detachment of the cardboard from the lining film 40.
From the aforegoing description the advantages of the cardboard container according to the invention are evident, although not limited to the particular embodiments described above and illustrated in the appended drawings, but numerous modifications of detail can be reached by a person skilled in the art, without thereby departing from the scope of the invention as defined by the appended claims.
Number | Date | Country | Kind |
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MI2004A 001084 | May 2004 | IT | national |