The present invention relates to a process for wrapping a product, in particular a confectionery product such as a praline or a chocolate, having a generally convex form in a wrapper of sheet material which can be sealed, tightly adhering to the surface of the product.

A process of the type to which the invention relates is described, for example, in EP 0 591 742 Al . In this case, the wrapper is obtained proceeding from two sheets, the first of which is shaped like a dish so as to wrap most of the product; the other sheet is then laid on the rest of the product so as to assume a form complementary to that of the product itself.

After the two sheets have been welded peripherally to give the wrapper sealing characteristics and the edges which project beyond the welding zone have been cut, the thus formed wrapper is subjected to a shaping step which causes the first sheet to cover practically the entire product, hiding the second sheet from view.

EP 1 046 579 A 1 describes a process of the type indicated above, with the aim of obtaining a shaped wrapper which comprises, as an integral part of the wrapper itself, a formation like a small cup ("fluted case"). In this case, following the achievement of an intermediate packaging formed by a first bowl-shaped sheet, with a containing wall including the product and a mouth surrounded by a radial flange, and by a second sheet arranged so as to overlap and possibly be connected sealingly to said radial flange, provision is made to shape the peripheral regions of said flange to obtain a wall which surrounds the containing wall of the first shaped sheet at a radial distance, forming a small cup ("fluted case").

This step is carried out by shaping means which comprise a forming cavity, which can receive in its interior the intermediate packaging, and a male element which can penetrate into the forming cavity like a punch, so as to compress the peripheral regions of the first and of the second sheet between the inner surface of the forming cavity and the outer surface of the male element. In order to improve the adhesion of the wrapper to the surface of the product, WO2008/018008 Al describes a process of the type in EP 1 046 579, in which the shaping of the small cup, integral with the packaging, is obtained by means of a mandrel with radially movable petals which are able to assume a radially retracted configuration in which the petals of the mandrel are able to penetrate into a forming cavity to improve the adhesion of the wrapper to the product and simultaneously shape a portion of the wrapper into the configuration like a small cup.

It is an object of the present invention to provide a process which further makes it possible to improve the adhesion of the wrapper to the outer surface of the product, thereby limiting the presence of air within the wrapper, which is made airtight by the adhesive or welding connection between the two sheets which constitute the wrapper itself.

It is a particular object of the invention to provide a process which makes it possible to achieve the contact of the wrapper virtually over the entire surface of the product, even when the product has an outer surface with small bumps and protrusions which act as spacers between the outer general surface of the product and the wrapper.

These bumps and/or protrusions are typical, for example, in a praline having a generally convex form, to the surface of which pieces of chocolate or of dried fruit or coconut shavings, for example, are applied.

In view of these objects, the invention relates to a process and an apparatus having the features defined in the claims which follow and which form an integral part of the present description.

The invention will now be described, purely by way of non-limiting example, with reference to the accompanying drawings, in which:

Figures 1 to 7 show successive steps of an embodiment of the process according to the invention;

Figures 1 a, 2a and 6a are realisation steps corresponding to those in Figures 1 , 2 and 6 in an alternative embodiment of the process; Figure 8 is a plan view of an iris tool used in the process;

Figures 9 and 10 are schematic plan views showing two configurations of the shutter means of the iris tool shown in Figure 8 and respectively shown in Figures 5 and 6 with the detail 12;

Figure 1 1 is a perspective view showing the final result of the packaging operation comprising the steps shown in Figures 1 to 7; and

Figures 12 and 13 are schematic views showing operational steps which follow the step shown in Figure 6 or 6a, in an embodiment of the process which leads to a product packaged in a sealed wrapper comprising a small cup or fluted case associated therewith.

The product which is to be packaged is constituted, in the exemplary embodiment shown, by a praline P with a spherical overall shape. In particular, this may be a praline which is constituted by a spherical wafer shell with a pasty and creamy filling, coated on the outside with chocolate or a similar coating, possibly with the application of granular food substances, such as coconut shavings, hazelnut pieces and the like, which give the outer surface of the praline an irregular overall aspect.

The process according to the invention is particularly advantageous for obtaining adhesion of the wrapper to an irregular surface of the type indicated above; however, the invention is also suitable for application to natural products having a different shape, but preferably having a generally convex shape, more preferably having a shape with one end or both ends shaped like a dome.

Still remaining within the confectionery sector, it is possible to refer to hollow or filled chocolate eggs, chocolates or pralines having an approximately spherical shape or with a flat bottom wall.

According to the invention, a sealingly adherent wrapper is formed around the product P using two sheets of aluminium or of other laminar material, denoted by 2 and 4 (see Figure 7 for the latter).

The preferred material constituting the sheets 2 and 4 can be aluminium or polypropylene; however, it is possible to use other plastic material which is suitable for contact with food or else paper or metallised paper; the sheets 2 and 4 can be present in a single layer or in a plurality of layers, for example composite materials or coextrudates such as aluminium/plastic material, paper/plastic material, paper/metallised plastic material. In particular, it is preferable for the two sheets 2 and 4 to be coated on their inner faces, which are intended to face the product P, by a welding lacquer or by a layer of thermowelding material, so as to allow the two sheets to be welded, as will be seen hereinbelow.

The two sheets can be of any desired shape but are preferably cut in advance into a circular shape.

The first step in the operation for packaging the product P consists in an operation for shaping, preferably by deep-drawing, the sheet 2 according to a cup-shaped general configuration (Figures 1 and 2). This operation is usually carried out by means of a tool comprising a mould 6 which, in its interior, defines a cavity 6a, into which a punch 8 having a shape which is substantially complementary to the cavity 6a can penetrate; in particular, the lower part of the cavity 6a of the mould has a shape which is exactly complementary to the shape of half of the product P which is intended to be wrapped by the sheet 2.

By means of the punch 8, the sheet 2 is thereby shaped according to a cup-shaped configuration comprising a bottom portion 2a complementary to said half or bottom portion of the product P, a tubular wall portion 2b defining a mouth adapted for the introduction of the product and an annular flange portion 2c surrounding the mouth; the tubular wall 2b has an axial extension (in height) such that it extends above the top of the product P when the latter is inserted in the shaped sheet; the tubular wall portion, which, as indicated above, extends between the plane of the annular flange 2c and the top of the product P, denoted by 2d in Figure 4, will be identified hereinbelow by the term neck portion.

In the next step (Figure 3), the product P is introduced in the sheet 2 shaped previously like a cup as indicated; in the illustration in Figure 3, the product is introduced in the shaped sheet when the latter is housed in the forming cavity 6; it is of course intended that this option is not binding, it being possible to extract the shaped sheet from the mould and transfer it into another mould or into another cavity formation which is able to support the sheet 2 with a view to introducing the product P.

According to a characterising aspect of the process according to the invention, following the introduction of the product P in the cup-shaped sheet 2, a bottleneck operation is carried out on the tubular wall portion 2b in its neck portion 2d, i.e. in the region immediately above the top of the product. This operation is carried out by binding the annular flange 2c or rather limiting its ability to move radially (according to the arrows F2 in Figure 5); in this way, the tubular wall 2b is fitted tightly adhering to the surface of the product, both in its bottom region and in the upper cap region.

Figures 4, 5 and 6 show a way of carrying out this operation, this being carried out with the aid of an iris bottleneck tool 12, with the aid of a pressure member 14 and with the aid of extraction means which are connected to vacuum and are associated with the iris tool 12.

According to an optional embodiment, shown in Figure 4, the shaped sheet, including the product, is lifted by means of a pusher member 10 which can slide in a through-hole through the mould, so as to make the neck portion 2d emerge from the forming cavity 6a.

The bottleneck operation is performed by means of the iris tool 12, one embodiment of which is shown in Figure 8. This tool comprises shutter means, denoted as a whole by 16 (Figures 9 and 10), which are movable between a configuration in which they define an enlarged opening (Figure 9) and a configuration in which they define a narrow opening (Figures 10 and 8). Said shutter means 16 comprise a plurality of petals 18, 20, 22, 24 (four petals in the example shown), the main faces of which are coplanar and which are associated with an annular plate 26. The plate 26 has a central opening whose profile is denoted by 28 (Figure 8) and a plurality of eyelets 30, 32, 34 and 36 in which a respective slider 38, 40, 42 and 44 protruding from the surface of the petals which faces the plate 26 engages. The petals are thus capable of linear translation movement relative to the plate 26 in the direction of the arrows F3, F4, F5 and F6 (Figure 9). The petals have respective front edge profiles 46, 48, 50 and 52 (i.e. the profiles facing the centre of the tool), which, in the enlarged configuration, define a central opening 54 having a dimension such that, when the iris tool is operated, to cause the bottleneck of the shaped sheet, in its neck portion, this opening surrounds the neck portion 2d.

The translation movement of the petals is controlled by means of an annular member 56, having a central opening whose profile is denoted by 66 (Figure 8) and which has a plurality of slits or radial eyelets 58, 60, 62 and 64 in which pins 68 protruding from the upper surface of the petals slidingly engage. The rotation of the annular member 56 (by means of the lever F7) controls the translation movement of the petals from the enlarged configuration to the narrow configuration, shown in Figure 10, in which the front profiles of the petals define a narrow central opening 70 (Figure 10 and Figure 8).

The radial dimension of the opening 70 is such that the sheet 2, following movement of the iris tool into the narrow configuration, has a narrow opening, such that the sheet covers some of the surface of the upper cap of the product P. In one embodiment (Figures 4 to 6), for performing the bottleneck operation on the sheet 2 in its neck region 2d, the shaped sheet is lifted from the deep-drawing cavity by means of a pusher member 10 so as to make the neck region 2d emerge (Figure 4). Then, the iris tool 12, associated with the mould 6, is moved from its enlarged position (Figure 5) to its narrow configuration (Figure 6). At the same time as or before the movement of the iris tool from the enlarged configuration to the narrow configuration, a pressure member 14 is moved in the direction of the arrow F8, so as to bind the annular flange 2c between said pressure member and the upper surface of the iris tool. The pressure exerted by the pressure member 14 can be regulated so as to block the edges of flange 2c or to limit by friction its ability to slide in the radial direction (arrow F2).

Since the flange is blocked or the ability thereof to slide is limited, the bottleneck operation causes the tubular wall 2b of the sheet 2 to be tightly fitted in substantial adhesion with the outer surface of the product.

Optionally or as an alternative, the shutter means 16, in their area of contact with the flange 2c of the sheet 2, may have through-holes 12a connected to vacuum (Figures 5 and 6), which is activated in order to bring about attachment of the shutter means to the flange 2c, during the bottleneck operation, further improving the adhesion of the wall of the sheet 2 to the surface of the product and the resultant evacuation of the air, before the sheet 4 is connected to the flange 2c.

The axial extension of the neck portion 2d is chosen so as to obtain an opening 70a (Figure 6) with a somewhat reduced dimension with respect to the original dimension of the mouth of the cup-shaped sheet.

The operation to lift the shaped sheet, shown in Figure 4, is to be considered purely optional and illustrative. As indicated in Figures la, 2a and 6a, it is indeed possible to carry out the deep-drawing of the sheet 2 in a mould 6 with an associated iris tool 12, such that the flange 2c is formed above the iris tool (Figure 2a).

The compression operation exerted on the annular flange 2c advantageously also flattens the annular surface of the flange, which, following the operation to deep-draw the sheet 2, generally has creases or small pleats, normally with a radial course. This provides a substantially flat annular flange 2c, to which the sheet 4 is connected (Figure 7) by means of thermowelding or possibly by bonding with the aid of adhesive material.

This provides a packaged product PI , which has the configuration shown in Figure 1 1 and is characterised by the presence of a narrow neck region 2d surrounded by a flange and formed by the adhesion of the annular flange 2c and of the sheet 4. In an optional subsequent operation, said flange can be shaped further, according to the direction of the arrows F9, so as to bring it into contact with the wall portion of the sheet 2 which surrounds the region of the narrow neck.

The process according to the invention can also be adopted for obtaining a product packaged in a sealed wrapper which comprises a small cup, or better a small cup with pleated walls ("fluted case"), following the optional operational steps shown in Figures 12 and 13, sequential to the operational step shown in Figure 6 or 6a.

In this embodiment, instead of using a second, flat sheet 4, use is made of a second sheet 4 which has been pre-emptively shaped (for example by deep-drawing) like a small cup, denoted by 5 (Figure 12), with a base wall 5a and a flared and preferably pleated side wall 5b.

Analogously to the operation described above with reference to Figure 6, the small cup or fluted case 5 is positioned, for example by means of a suction tool U, with its base wall 5a resting on the flange 2c of the first sheet (Figure 12), with the concavity of the small cup facing in the direction opposite with respect to the flange 2c, or, in the example illustrated, upwards. The base wall 5a and the flange 2c are then connected by bonding or preferably by fhermowelding or ultrasonic welding. If the connection is made by means of therm owelding or ultrasonic welding, the small cup 5, on its outer surface, or at least on the surface of the base wall 5a facing the flange 2c, has a coating formed by a film of thermoweldable material, for example a welding lacquer or a polyethylene composite.

Once the welding operation has been carried out, with the use of a welding plate, the side wall 5b is folded by 180° according to the arrows F10 by means of an appropriate tool Ul , so as to bring said wall into a position in which it surrounds the wrapped product, at a slight distance therefrom (Figure 13). Of course, this embodiment involves a final operation to turn the product by 180° such that the base wall 5b of the small cup acts as a bearing surface for the packaging.

The process according to the invention therefore achieves the object of obtaining a substantially sealed wrapper which insulates the product from contact with air and which adheres precisely to the outer surface of the product. It goes without saying that the process according to the invention can be automated and applied in an industrial field providing for the simultaneous packaging of a plurality of products. Clearly, without departing from the principle of the invention, the embodiments and in particular the constructional details may be greatly varied with respect to that described and illustrated purely by way of non-limiting example, without departing from the scope of the claims which follow.