The present invention relates to a plant for packaging confectionary products in a sterile manner in sterile containers or packages.

In the foodstuffs industry, in general, and in the field of packaging of confectionary products in sterile containers, in particular, there is felt the need to package products in containers having formats different from one another. For said purpose, for each format, i.e., for each type of container, there is currently used a packaging plant "dedicated" to the specific container.

Each of said plants, commonly known as "form/fill/seal" and disclosed for example, in US 3.911, 640, comprises a plurality of stations, which are aligned with one another along a packaging path and are all housed within a common tunnel that defines a "sterile" area or rather an area controlled in its degree of bacteriological contamination in order to ensure the sterility of the packaging. Fed step by step through the aforesaid stations is a first thermoformable strip, which defines an end wall of the tunnel and, after being sterilized, is heated, in a purposely designed station, and then passes into a thermoforming station for making one or more housings or compartments designed to receive, each, at least one of the aforesaid products. The compartments with the products to be packaged inside are then sealed by means of a second strip that is also previously sterilized and that delimits at the top a terminal length of the aforesaid tunnel and is heat-sealed on the first strip before the various compartments are physically separated from one another in a dinking station.

Even though the known plants of the type described above are currently in use, since they are dedicated' to a given container, they present a "rigid" configuration and consequently cannot be drastically modified for producing containers that may even be very different from the ones originally envisaged. It is, however, possible to make partial modifications to the known plants, said modifications in any case requiring particularly long adaptation times and generating unacceptable losses in terms of downtime of the plant and, hence, of lack of production.

Furthermore, in known plants, precisely because they are dedicated, the width of the strips and the step of advance of the strips themselves are already determined in the design stage and optimized as a function of the dimensions, geometry and, in general, type of individual format or container originally conceived so that the change in format inevitably generates an increase in waste, i.e., in the amount of strips not used in the processes of thermoforming and/or closing, to such an extent as to render production less economically advantageous given, as is known, the high incidence of the cost of the strips on the overall cost of the packaged product.

The use of strips of different width on existing plants is ruled out by the fact that the strips delimit the sterile area and for this reason must be constantly coupled in a sealed way to a wide range of mechanical components of the plant, which would, in turn, have to undergo modifications or adaptations that entail insurmountable difficulties. For the reasons set forth above, each substantial change of format of the containers requires replacement of the entire packaging plant.

Change of formate of the containers is possible using the adjustable plant disclosed in DE 203 05 759U1.

The aim of the present invention is to provide a plant for packaging confectionary products in sterile containers, the constructional characteristics of which enable a simple and inexpensive solution of the problems set forth above.

According to the present invention a plant for packaging confectionary products in sterile containers is provided, the plant comprising, arranged along a packaging path, at least one first assembly for sterilization and heating of a first thermoformable strip, a forming assembly for making on said first strip at least one compartment for housing said confectionary products, an assembly for feeding a confectionary product into said compartment, a second assembly for sterilization and feed of a second closing strip towards said first strip, a welding sealing assembly for connecting together said strips and closing said confectionary product within said housing compartment, a cutting assembly for cutting said strips and making at least one said container, and a sterile duct extending along said packaging path and designed to contain a sterile gas, said duct being common to said assemblies and being delimited at least partially by said strips, the plant being characterized in that each said assembly forms part of a respective operating module that is independent of the other modules and coupled to the adjacent modules in a releasable way.

Preferably, in the plant defined above, each said module comprises a respective supporting frame that is independent of the supporting frames of the other modules, the frames supporting respective operating means designed to perform the specific function of said module and part of the frames themselves a respective half-shell casing distinct from the other casings and connected to the adjacent casings via releasable sealing means; each said casing delimiting a respective length of said sterile duct.

The invention will now be described with reference to the attached figures, which illustrate a non-limiting example of embodiment thereof and in which:

• Figure 1 is a schematic perspective view of a preferred embodiment of the plant according to teachings of the present invention;
• Figure 2 is similar to Figure 1 and illustrates the plant broken down into some of its constitutive elements;
• Figure 3 illustrates, at an enlarged scale, a detail of
• Figures 1 and 2; and
• Figure 4 illustrates, in perspective view, a component of the plant of Figures 1 and 2.

In Figure 1, designated as a whole by 1 is a plant for packaging confectionary products in sterile containers. Here and in what follows by the term "confectionary products" is meant both products in a solid or granular form and products in the form of a liquid or a cream.

The plant 1 has a modular composition or is made up of units that are mutually independent, i.e., autonomous from the mechanical, electrical, electronic, pneumatic, and management standpoints. In the specific case, the plant 1 comprises, in succession along a packaging path P, a module 3 for feed and sterilization of a thermoformable strip 4, which is wound off a spool 5 and fed step by step along the packaging path P by drawing devices, which are known and not described in detail. The plant 1 then comprises a module 6 for heating of the thermoformable strip 4 and a module 7 for thermoforming of the thermoformable strip 4 itself. The module 7 provides on the strip 4 a plurality of housings or compartments 8 having dimensions and relative positioning determined in the design stage according to the product, the type of container to be made, and the width of the strip 4 itself.

Downstream of the module 7, in the direction of advance of the strip 4, the plant 1 further comprises a dispensing module 9 for feeding the product to be packaged into each of the housings or compartments 8, and a further module 10 for feed and sterilization of a heat-sealable strip 11 that can be wound off a spool 12 carried 'by the module 10 itself. Downstream of the module 10, the plant 1 further comprises a welding module 13 for welding the strip 11 onto the portion of the strip 4 not involved the previous thermoforming process so as to close in a fluid-tight way each of the housings or compartments 8, and a dinking module 14 for separating the various housings or compartments 8 from one another to form a plurality of sterile containers, which are fed towards an outlet 15 of the plant 1 by a conveyor belt 16 that forms part of the dinking module 14 itself.

Each of the modules 3, 6, 7, 9, 10, 13 and 14 comprises a respective operating assembly, which is in itself known; said assemblies are designated by 3a, 6a, 7a, 9a, 10a, 13a and 14a, respectively. The operating assemblies are pneumatically connected to a pneumatic source via dedicated valve assemblies of their own (not illustrated) and electrically connected to respective electronic control units 3b, 6b, 7b, 9b, 10b, 13b and 14b. The electronic control units 3b, 6b, 7b, 9b, 10b, 13b and 14b are each dedicated exclusively to the corresponding operating assembly 3a, 6a, 7a, 9a, 10a, 13a and 14a, are independent of one another, and are, in turn, electrically connected and controlled by a general control unit 18 for managing the entire plant 1.

Each module 3, 6, 7, 9, 10, 13 and 14 further comprises a respective structure or frame 3c, 6c, 7c, 9c, 10c, 13c and 14c for supporting the corresponding operating assembly 3a, 6a, 7a, 9a, 10a, 13a and 14a and the various electrical and pneumatic wiring/components; each frame 3c, 6c, 7c, 9c, 10c, 13c and 14c is separate from and independent of the other frames and is set alongside and coupled to the frames adjacent thereto in a releasable way, for example via fast-coupling assemblies (not visible in the attached figures). Each frame 3c, 6c, 7c, 9c, 10c, 13c and 14c is supported by a guide-and-slide assembly of its own, comprising a slide defined by a plurality of bottom resting feet or portions 20 (Figures 1 and 3) of the respective frame itself; in the particular example described, the portions 20 have respective bottom terminal seats 21 shaped like a U set upside down and engaged by a corresponding rectilinear guide 22 in a slidable way. The guide 22 forms part of the aforesaid guide-and-slide assembly and part of a rail 23 for relative positioning, which is common to all the modules 3, 6, 7, 9, 10, 13 and 14, extends parallel to the path P, and is stably fixed on the floor. In this way, each of the modules 3, 6, 7, 9, 10, 13 and 14 can be translated along the rail 23 and hence along the aforesaid packaging path P independently of the other modules and, in particular, can be uncoupled from the rail 23 itself and moved away by simple vertical lifting, as illustrated for the module 9 in Figure 2. Alternatively, according to a variant not illustrated, one or more modules have their respective frames arranged, each, on a respective motor-driven trolley or other equivalent means for movement of the module, designed to be controlled in position independently of the other trolleys, for displacement in a direction transverse to the aforesaid packaging path P, between an operative advanced position, in which the corresponding frame extends along the path P in a pre-determined position, and an extracted position, in which the frame is set outside of the packaging path P and in which the module does not take part in the packaging process.

Each of the frames supports an intermediate resting surface K, which is substantially coplanar to the surfaces K of the other frames, and on which the thermoformable strip 4 rests during its advance towards the outlet 15. In this way, the various surfaces K define at least part of a sliding guide for the thermoformable strip 4. At output from the dinking assembly 14, the containers are moved away via the conveyor belt 16.

Each of the frames arranged upstream of the sealing assembly 13 moreover supports a respective half-shell 3d, 6d, 7d, 9d and 10d, which is set only above the'corresponding resting surface K with its concavity facing the corresponding plane surface K itself and is coupled to the half-shells adjacent to it in a releasable way via the interposition of respective gaskets or labyrinth seals designated by 25. In the particular example described, each half-shell 6d, 7d, 9d and 10d comprises a corresponding top wall 26 set facing, and superimposed only on, the corresponding plane resting surface K and vertically raised with respect to the corresponding plane surface K itself, and two side walls 27, which face one another and extend upwards once again starting from the respective flat resting surface K. Each of the top walls 26 has a size measured parallel to the corresponding surface K and orthogonal to the path P that can be varied as a function of the width of the thermoformable strip 4 and of the strip 11 and a through opening traversed by a mobile element of the respective operating assembly 6a, 7a, 9a, 10a. The side walls 27 terminate, instead, in the direction of the corresponding resting surface K, with respective portions, which, in the case in point, are L-shaped (Figures 2 and 4), to which the opposite longitudinal lateral portions of the thermoformable strip 4 are coupled in a slidable way so as to guarantee maintenance of an overpressure of the sterile environment within the tunnel. In this way, each half-shell 6d, 7d, 9d and 10d delimits, with a corresponding intermediate portion of the thermoformable strip 4, a respective length of a continuous tunnel 30 (Figure 4), which is closed upstream by the feed and sterilization assembly 3 and downstream by the closing strip 11, which progressively converges towards the underlying thermoformable strip 4 before being welded to the thermoformable strip 4 itself. Supplied into the tunnel 30 is sterile air and, in general, a sterile gas containing nitrogen at a variable pressure of between 0.01 and 1 bar to create a sterile environment, in which all the packaging operations are performed.

From the foregoing description, it is evident how the constructional characteristics of the plant 1 described and, in particular, the fact of using a plurality of modules or units completely independent of one another and autonomous from the mechanical, electrical, electronic, pneumatic, and management or control standpoints but that can be coupled to one another in a functional way enables, according to the needs, transformation in an extremely fast way and hence with reduced downtimes, of an existing packaging plant into a new plant for packaging a different type of product or for the production of different containers, maintaining the efficiency and reliability of the previous plant unvaried but, above all, reducing to a minimum the machining waste. What has just been set forth is basically the result of the fact that each one of the modules that make up the plant 1 is perfectly interchangeable or replaceable with another functionally equivalent module, i.e., a module that performs the same function as the replaced module and can be chosen from among a plurality of modules having constructional characteristics different from one another. By the term "constructional characteristics" is meant the characteristics of the module that enable variation of the type, i.e., geometry and/or dimensions, of the containers produced.

Furthermore, other features remaining the same, the fact of envisaging, for each of the modules 6,7,9 and 10, a corresponding adjustable half-shell for forming the sterile environment enables arbitrary variation of the transverse dimensions of the tunnel 30 and makes it hence possible to use thermoformable and closing strips of different width. In the particular example described, in fact, the half-shells provided enable use of thermoformable and closing strips of widths that vary in a percentage of ±15% with respect to a given width and hence optimization of the surface of the thermoformable strip 4, reducing to a minimum the waste resulting from dinking.

Finally, the fact of using a common guide rail and of coupling the different modules to the same rail in an axially slidable way makes it possible, on the one hand, to ensure always a precise positioning of the modules along the path P of advance, and on the other, to replace any of the modules by simply sliding the others along the rail. Furthermore, sliding along the rail enables replacement of an existing module with another module having a different longitudinal dimension, i.e., a dimension measured in the direction of the packaging path. In other words, the new module may be positioned in a space not necessarily identical to the one left free by the previous module. Furthermore, said implementation enables insertion of additional modules that are able to satisfy different working processes, e.g., working processes that comprise a number of a dispensing station.

From the foregoing description it emerges clearly that modifications and variations may be made to the plant 1 described, without thereby departing from the sphere of protection defined by Claim 1.

In particular, the plant 1 could comprise a number of modules different from the one indicated by way of example, and said modules could present frames or shapes that differ from the ones indicated once again by way of example.

Furthermore, the half-shells for obtaining the sterile environment could be provided in a way different from the one indicated by way of example once again in the perspective of facilitating transformation of the plant according to the widths of the strips to be used.