DESCRIPTION.

Container made of Sheet Material, particularly for Foodstuffs.

The present description relates to a container made of paper material, in particular suitable for containing food products.

In particular the invention relates to a container made of paper material realised in a single sheet suitable for containing confectionary products, pastries or the like, commonly known to operators in the sector as paper cases.

BACKGROUND OF THE INVENTION.

As is known, small paper-material containers have been widely available for many years on the market, which containers are made starting from a single flat sheet which is then shaped by forming operations.

In particular, these containers exhibit a base wall, generally circular, from which a suitably-pleated side wall emerges such as to account for the excess of material following the deformation out of the plane of the sheet from which the container is obtained.

In particular the lateral wall emerges from the base wall inclined with respect to the vertical such as to define a container having an upturned truncoconical section where the upper opening is greater in surface area than the base.

Containers made of paper material are realised in this profile such as to be appropriately stacked for the purposes of logistical management of the product itself.

In this regard, the angle of inclination with respect to the vertical is on average in a range comprised between about 10 and 20 degrees.

During the use stage, this type of container in the stacked configuration is loaded on suitable unstacking machines destined to remove a container at a time from the stack and position them successively at further stations of the machine, where the further operations are performed, such as positioning internally of the cavity of the container of a food product and the relative packing of the product itself.

These containers today efficiently serve the purpose they are designed for, guaranteeing ease of transport, good separability using automatic machines and an extremely low cost connected to an extremely simple production process which includes a male punch and a female punch, substantially complementarily shaped to the final product to be realised.

Though they are destined for uses and markets that are different from the ones mentioned above, the containers disclosed in patent FR 2767513 fall within the typology of the above-described products, at least from the geometrical point of view. Apart from the trunococonical shape as mentioned above, cake containers having a different section in a vertical plane have been described, for example in patent EP 1253090 by the same Applicant.

Patent EP 1253090 discloses some novel shapes in which the lateral wall exhibits zones curved towards the centre of the cavity defined by the base and the lateral wall of the container such as to obtain particular container shapes, for example suitably shaped for more fully containing the food product.

Patent WO 2010/092538 illustrates further embodiments and a novel method for obtaining them. The products marketed and/or proposed, as briefly described above, well satisfy market needs but have shown themselves to have some drawbacks.

In particular, the containers destined for cooking and raising of pastry products which exhibit an inclined lateral wall interfere with the rising of the product, as they allow the food product to increase in size not only along a vertical direction but also along a horizontal direction in the zones proximal to the lateral wall.

Operators see this as a drawback both because of the ensuing inequality of raising and due to the effect on the final appearance of the product, which might not be the best possible.

In addition to the foregoing, the need to realise flared containers so that they can subsequently be stacked leads to a situation in which, between a container and a next in a stack, but especially between first containers at an end of a stack and final containers at the opposite end of the stack, there exist small differences in terms of the diameter of the base. These differences appear necessary and obvious in order to allow excellent stackability of the containers, and also derive from a partial further deformation caused by the stacking operations.

Though these differences in diameter are substantially imperceptible for a common user, the operator, in positioning the container in a cooking tray or a pack, is more aware of these slight differences in diameter, which also lead to some centring problems during the step of filling the container with the food product and/or transport of the pack itself.

SUMMARY

The aim of the present invention is substantially to obviate one or more of the above-evidenced drawbacks in the prior art.

A first aim of some of the illustrated embodiments is to provide a process for obtaining containers made of paper material which enable excellent rising of the product in a vertical direction.

A further aim according to an embodiment described herein below is to obtain containers that are geometrically and dimensionally extremely alike, if not identical to one another.

A further auxiliary aim is to provide a process and a relative container which enable, during the storing and logistical stages, maintaining the optimal characteristics of stackability and thus the smallest possible volumes, while, during the stage of use of the product, attaining the objectives of excellent rising and geometrical precision as mentioned above.

Lastly, a general aim of embodiments that will be presented in the following is to contain the production and logistical costs to amounts that are entirely comparable, if not identical, to those of the products at present on the market.

These and other aims which will better emerge during the course of the following description are substantially attained by one or more of the accompanying claims, possibly in combination with one another.

Further characteristics and advantages will more fully emerge from the detailed description of an embodiment according to what is described of a method for realising containers in sheet material and the relative container thus obtained.

The detailed description will be performed with reference to the accompanying figures of the drawings, provided purely by way of non-limiting example, in which:

figure 1 is a container made of paper material according to the prior art;

figure 2 is a container made of paper material according to an embodiment described in the following; figure 3 is a container made of paper material according to a further embodiment described in the following;

figure 4 is the container of figure 3 in a view from above;

figure 5 is a container made of paper material according to a third embodiment described in the following;

figure 6 is a further embodiment of the container of figure 2;

the sequence of figures 7A-7D schematically illustrates the various productive stages of the container according to preceding figures from 2 to 6;

figure 8 illustrates a variant of the equipment of figure 7 for realising a container according to what is described; and

figure 9 is a further variant of the equipment of figure 7 for realising a container according to what is described.

With reference to the figures of the drawings, 1 denotes in its entirety a container made of sheet material, in particular paper material, suitable for containing products such as food products, confectionary, pastries or the like.

In particular, the present invention relates to containers made of sheet material, in particular paper, made by deforming operations (in particular successive, as will be more fully clarified in the following) starting from a substantially flat single sheet of paper material.

The containers exhibit, in general, a base 3 and a lateral wall 4 emerging distancingly from the base such as to define a containing cavity 5, for example of the food product.

The base wall 3 is in general substantially flat and circular, and the lateral wall 4 is realised in a single piece with the base wall 3.

Further, in a section according to a horizontal plane substantially parallel to the base plane 3, the lateral wall 4 exhibits an undulated profile 18 with a closed and generally circular progression (see figure 4).

In particular, the undulating profile 18 with a sinusoid section is connected to the presence of excess of material that is created during the stage of folding the sheet starting from the flat situation towards the three-dimensional configuration; this excess of material is distributed thanks to the generation of a pleating which generates respective loops 16 and protrusions 15 with respect to a mean circumference.

In general the description that follows will refer to containers of average and/or small dimensions (though not limitedly), in which the base diameter goes from a few centimetres to about 20 centimetres at most.

Also of note is that the containers described herein are realised in paper for alimentary use, i.e. suitable for contact with food products without contaminating them, or without being subject to breaking up.

The present invention relates to a special process for realising containers in sheet material, in detail paper material, of the type mentioned above.

The method first comprises a first stage of realising by deformation a container 2' (intermediate) having a first configuration; the container 2' is made starting from a substantially flat sheet material, typically paper.

The intermediate container 2' illustrated in figures 2, 3 and 6 in broken lines is also shown in figures 7A and 7B and is in general entirely identical to the container known in the prior art (figure 1).

The intermediate container 2' comprises a base 3', a lateral wall 4' emerging distancingly from the base, which in cooperation define a containing cavity 5' that is superiorly open such as to enable insertion and/or access to the base 3'. In particular, in section according to a perpendicular plane to a plane containing the base 3', the lateral wall 4' exhibits a profile having at least partly an inclined profile with respect to the normal to the base 3'.

In general, in the following reference will be made to a plane containing the base 3', with the understanding that in most cases the base is flat, though without excluding the possibility of realising base walls that are slightly curved (for example concave or convex) without forsaking the inventive concept of the present invention.

In general the container 2' exhibiting the first configuration will have, in section according to the perpendicular plane to the base 3', an upturned taincoconical profile with an angle a of inclination of the lateral wall 4' with respect to the perpendicular to the base 3' that is greater than 5 degrees (see figure 10).

As mentioned above, the intermediate container 2' will be substantially similar, if not identical, to the containers illustrated in figure 1 in relation to the prior art.

Note that an angle of inclination a' of the lateral wall 4' greater than 5 degrees is necessary in order to be able to realise the container by forming.

In the absence of a sufficient angle between the base 3' and the lateral wall 4', it is substantially impossible to apply the necessary pressure by means of the male and female punches during the forming stage that is required for the deformation of the intermediate container 2'.

In general, a plurality of the intermediate containers 2' having the first configuration is realised, which, as is usual in today's practices, is then stacked such as to define a plurality of containers of the type illustrated in figure 7a.

Note however that the containers are necessarily taincoconical with the aims of enabling stackability and easy management of the transport and storage thereof, with a minimum occupation of spaces. In general, and as will be more clearly expressed in the following, the process of realisation comprises a subsequent stage (which is also separate) of forming of the intermediate container 2', in which subsequent stage a portion of the lateral wall 4' is further deformed such as to bring the portion of the lateral wall 4' at least partially into the median plane containing the base 3' such as to define a final container 2 having a second configuration that is different from the first configuration.

In still other terms the process includes two distinct deformation stages of the single sheet material in order to bring it into a first configuration (container 2' - figure 1 or figures 2, 3 and 6, in broken lines) and then into a second and distinct stage of deformation which is carried out subsequently in which the intermediate configuration is modified.

Observing the sequence of stages in particular illustrated in figures 7a-7d, it can be seen how once a plurality of the intermediate containers 2' is realised, they are stacked on one another; in a further process (for example in industrial use of the single paper material containers) a predetermined number of containers 2' are removed and in particular an end container in the stack 100 of containers, which is then placed on a reference plane where it is blocked in position; in particular the base 3' of the intermediate container 2' in the first configuration is blocked by use of the gripping means 10. The example of figures from 7a to 7d illustrates the use of two opposite bodies 6,7 which, during the gripping stage, abut one to the other with the base 3' interposed between them (condition of figures 7b - 7d).

Thereafter a punch is moved, which punch bears a male portion 11 which nears from outside the cavity 5' towards the inside thereof, being directed towards the base 3' (figure 7B).

A lower surface 12 of the male portion 11 exhibits a plan area that is greater than that of the base 3' and acts by pressure on the lower portion of the lateral wall 4' such as to crush it and bring it into the median plane containing the base 3' (see figure 7c).

In this way the container 2' is further deformed, bringing it from the first configuration to take on the second final configuration illustrated in a continuous line in various possible embodiments in figures 2, 3, 5 and 6, detailed in the following.

Note that the profile of the male portion 11 of the die can be one or more of those shown in figures 7b (circular external profile), 8 (full profile with a sliding guide on one of the opposite blocking bodies) or figure 9 (full portion, for example truncoconical), as long as in its motion and its interaction with the container 2' in the first configuration it interacts with the lateral wall 4' thereof in order to modify the geometric configuration thereof, and in particular such as to bring the portion from a condition in which it is distancing from the base 3' to a condition in which, conversely, it is lying substantially in the same plane as the base.

Obviously other and different configurations of the male portion 11 of the die can be equivalently adopted and produce the above-described technical effect.

With reference to the gripping means 10 too, a specific embodiment of which is illustrated in figures 7b-7d, other alternatives can be provided such as, for example, the embodiment of figure 9, in which the container 2',ίη accordance with the first configuration and before the subsequent deformation to take it into the second configuration, is retained in position by means of a device 17 which acts by depression.

Obviously other and equivalent systems can equally be used.

Although not necessarily, the present method is applicable in particular to containers which in the intermediate first configuration 2' exhibits a profile in a vertical plane that is truncoconical and which further exhibit a circular base 3', a pleated emerging lateral wall 4' having a section such as the one illustrated in figure 4, and an upper opening delimited by a profile also having an overall sinusoid circular progression.

Thus in general the container 2', in the first configuration, will exhibit an axis of symmetry 13 that will in general be a cylindrical axis of symmetry and the male portion 11 will exhibit a respective axis of symmetry 14, in this case too a cylindrical axis of symmetry.

The relative movement between the male portion 11 and the base 3' occurs in particular along one of the axes of symmetry 13, 14 and in general, during the stage of relative movement, two axes will coincide (figure 7B).

Note in particular that the lower surface 12 of the male portion will have a circular external development such that following the subsequent deformation the container, in the second configuration, will again have a circular base 3.

In still other terms, the portion of the lateral wall 4' brought into the median plane containing the base 3', in the second configuration, takes on the shape of a circular crown 9 positioned with respect to the base 3' of the container 2 in the first configuration.

In particular, the circular crown 19 is clearly illustrated in figure 4, which evidences a view from above or equivalently a section of the container 2 of figure 3.

In particular, the faint irregular broken lines that can be observed in the circular crown 19 of figure 4 correspond to the plurality of radial folds that have been flattened following the stage of crushing performed in the stage of figure 7c, i.e. the stage of crushing using the male portion 11 of the die.

In still other terms, the crown 19 of the final container 2 in the second configuration, while substantially a flat portion, manifests some small irregularities connected to the deformation of the sheet material when in the first configuration, being folds which generally have a radial extension, and which are flattened, but do not disappear, in the final configuration of the container 2.

Observing in particular the effects the following deformation stage achieves, it is firstly visible that there is a reduction in height h of the container 2 having the second configuration with respect to the preceding height h' of the container having the first configuration.

This appears obvious in the light of the fact that a lower portion 20' of the lateral wall is crushed, taking it into a flat configuration, and therefore the height of the container (defined by the remaining portion of the vertical part) is red uced .

Note also that the following deformation stage also leads to a change in the mean inclination a of the lateral wall 4 of the container 2 having the second configuration with respect to the mean inclination a' of the lateral wall 4' of the container 2 in the first configuration (figure 10).

In particular, this variation due to the recuperation of the paper material can assume different values according to the dimensions of the circular crown 19 (in particular the maximum external radius B, B',

B") thereof which is defined.

In fact, by crushing only a small part of the lower portion 20' of the lateral wall 4', a container is obtained of the type illustrated in figure 2, in which the inclination of the lateral wall 4 with respect to the perpendicular to the base 3 is reduced almost to the perpendicular.

In still other terms, with an angle a of inclination of the lateral wall 4 defined with respect to the perpendicular to the base 3' which will be, as explained, greater than 5°, the successive deformation stage will lead to a reduction of the inclination of the lateral wall 4 of the container 2 having the second configuration and in particular an angle a of the lateral wall 4 having a value of less than the angle a' of the lateral wall 4' of the container 2' of the first configuration.

The angle with respect to the vertical reference can go from the value of greater than 5° of the first configuration to a value of less than 5° (for example figure 2) up to a value of about close to 0° (configuration of figure 3) or even less than 0° (configuration of figure 6).

An angle of 0° has been considered as that of the perpendicular to the bottom wall 3; this angle increases in a clockwise direction and becomes negative in the anticlockwise direction.

The variation of the angle of inclination up to negative values will be determined by the radial dimensions of the circular crown 19.

The greater the diameter (B<B'<B") of the base 3' of the container 2 in the second configuration, the smaller the angle a defined .

In still other terms, the substantially circular base 3' will have a smaller diameter than the substantially circular base 3 of the container in the second configuration.

The base 3 will have generally a greater diameter by at least 5% than the diameter of the base 3' of the container 2' of the first configuration.

Lastly, note that the final container 2 of figure 5 exhibits a reinforcement 10 defined by a flaring of the base 3 at the external perimeter thereof.

This reinforcement 10 will emerge slightly downwards with respect to the plane containing the base 3. In order to more carefully detail and clarify the modifications between the first and the second configuration, note in figure 10 how the intermediate container 2' in the first configuration exhibits a base edge 8' (in general circular) defined by the meeting of an external portion 9' of the base 3' and a lower portion 20' of the lateral base 4'.

Following the step of deformation of the lower portion 20' of the lateral wall 4', the container 2 of the second final configuration will also exhibit a base edge 8, defined however by the meeting of a lower portion 20 and the lateral wall 4 and by an external portion 9 of the base 3.

This final external portion 9 will be constituted by the preceding lower portion 20' of the lateral wall 4' of the container 2' of the first configuration.

In other terms, the base edge 8' that was will be (in the final container 2) a flattened fold defining the internal diameter A of the circular crown 19 (see figure 4), while the new edge 8 will be defined at the line from which the lateral wall 4 (external diameter B) emerges.

The above process and the container thus obtained provide various advantages.

Firstly it will be possible to operate with common machines already known in the art in order to realise containers having a truncoconical profile, insert them into one another, and transport and manage them efficiently.

However, with a simple and subsequent stage of deformation, which can be performed directly in the stage of use of the single containers, the profile of the truncoconical container can be modified, bringing it to assume, for example, a substantially cylindrical shape in which, in particular, the diameter of the base 3' can be precisely controlled, being defined, or rather re-defined, for all the containers, by the external diameter of the male portion 11 of the die.

In this way, once successively deformed so as to take on the second configuration, all the containers will assume the same configuration, and in particular the same base diameter will be guaranteed. The above leads to significant advantages in terms of automated management of the containers and their positioning in baking trays, for example for cooking or packing the finished food product.

Further, the configuration of the lateral wall can be changed from inclined to substantially vertical in such a way as to make available containers made of paper material with an undulating lateral wall having a cylindrical profile.

The foregoing improves the performance of the container during baking of a food product, and in particular when the product is rising, as it is precisely directly uniformly at all points of the container. Finally, the process for obtaining cylindrical containers having a controlled profile is extremely efficient and the costs extremely contained such as not to have a significant impact on the production processes, while enabling the previously-mentioned drawbacks to be obviated.