MACHINE AND METHOD FOR THE HERMETIC PACKAGING OF

FOOD PRODUCTS

Technical field

This invention addresses the field of industrial packaging of food products. More specifically, this invention relates to a machine and method for the hermetic packaging of food products, and in particular, biscuits.

To package food products with a flat or disc shape, which industrially made biscuits typically have, the products are disposed in a neat stack and then wrapped in a wrapping material.

Background art

More specifically, wrapping is carried out by first placing the wrapping material around the lateral surface of the stack and sealing the wrapping material along the direction of extension of the stack and then closing the wrapping material at the bases of the stack to obtain a hermetic package which helps preserve the nutritional and organoleptic properties of the product. Disclosure of the invention

In this context, the technical purpose which forms the basis of this invention is to propose a machine and a method for the hermetic packaging of food products, capable of making a package alternative to the prior art according to a different process.

The technical purpose indicated and the aims specified are substantially achieved by a machine and a method for the hermetic packaging of food products comprising the technical features set out in one or more of the accompanying claims. The dependent claims correspond to possible different embodiments of the invention. Brief description of drawings

Further features and advantages of this invention are more apparent in the following non-limiting description of a preferred but non-exclusive embodiment of a machine and a method for the hermetic packaging of food products.

The description is set out below with reference to the accompanying drawings which are provided solely for purposes of illustration without restricting the scope of the invention and in which:

Figure 1 shows a perspective view of a stack of food products packageable with a machine according to this description;

Figure 2 shows a schematic view of a machine for the hermetic packaging of food products according to this description, disposed in a configuration according to a step of a method according to this description;

Figure 3 shows a schematic view of the machine of Figure 2 in a different configuration according to a different step of a method according to this description;

Figure 4 shows a schematic view of a machine for the hermetic packaging of food products according to this description, disposed in a configuration according to a step of a method according to this description;

Figures 5A to 5C show schematic views of a detail of the machine of Figure 4 in successive steps of a method according to this description;

Figure 6 shows a perspective view of a stack of food products packaged with a machine according to this description.

Detailed description of preferred embodiments of the invention

With reference to the drawings, a machine for the hermetic packaging of food products is denoted in its entirety by the numeral 1 and is hereinafter referred to as“machine 1” for short.

The machine 1 is configured for packaging food products“A” having a flat, cylindrical, disc, or parallelepiped shape, and disposed in a stack. Preferably, the food products “A” are ready-to-eat foods such as, for example, chocolates, sweets, biscuits or snacks.

The machine 1 comprises a movement unit 10 having an infeed station configured for receiving a plurality of food products“A”: for example, from a production line upstream to which it is connected.

Preferably, the movement unit 10 comprises a conveyor belt 12 adapted to receive a plurality of food products“A” disposed in neat stacks“P” at the infeed station and to transport the food products“A” from the infeed station to the next transfer station “S2” while keeping them in the stacked configuration.

Looking in more detail, each stack“P” is in the form of a pack of food products“A” which is ready to be wrapped and which is disposed along a stacking axis“X”, as illustrated in Figure 1.

Each stack“P” has a first and a second base surface “P1” and“P2”, opposite and parallel to each other, and a lateral surface (P3) interposed between them and defined jointly by all the lateral surfaces of the stacked food products“A”.

For example, if the food products“A” are disc-shaped biscuits, the stacks “P” have a cylindrical lateral surface“P3”.

To receive and keep the stacks“P” of food products“A” in the stacked configuration while they are being moved, the conveyor belt 12 is provided with a plurality of gripper teeth 13 disposed in such a way as to define a plurality of containing seats 14 for the stacks“P”.

More specifically, the containing seats 14 are configured for accommodating the stacks“P” in such a way that the first, lower base surface“P1” of each of them rests on a flat surface of the conveyor belt 12 and the teeth 13 engage the lateral surface“P3” to keep the food products “A” disposed along the stacking axis“X”.

Preferably, the front and rear portions of the lateral surface“P3” of each stack“P”, relative to the direction of movement of the conveyor belt 12, are left free by the teeth 13.

The movement unit 10 also comprises a transfer element 16 configured for extracting the stacks“P” of food products“A” from the containing seats 14 in the transfer station“S2” and transferring them to a pickup station“S3”. Preferably, the transfer element 16 comprises carriers 17 of the gripper type configured for engaging the portions of the lateral surfaces“P3” of the stacks “P” not engaged by the teeth 13 of the conveyor belt 12, for engaging, in particular, the front and rear portions described above, as illustrated in Figure 2.

The carriers 17 are configured for gripping the stacks“P” firmly along their lateral surface “P3” and moving while maintaining the stacked configuration, preferably in such a way as to maintain the front and rear portions oriented along the direction of movement of the respective stack

“P”

In the preferred embodiment, the transfer element 16 is configured for moving the carriers 17 both translationally and rotationally. More specifically, the transfer element 16 is configured for moving the“stacks “P” away from the transfer station “S2” according to a translational movement along the stacking axis“X” to disengage the containing seats 14.

Next, the transfer element 16 is configured for moving the stacks “P” transversely to the respective stacking axis“X” according to a rotational movement up to the pickup station“S3” in such a way that the stacks“P” can be gripped by machinery downstream, as illustrated in Figure 3.

The machine 1 comprises a conveyor 20 configured for receiving the stacks “P” of food products “A” from the movement unit 10, and in particular from the transfer element 16, and moving them along a predetermined feed path between the pickup station“S3” and a release station“S4”.

In the preferred embodiment, the conveyor 20 comprises a plurality of grippers 21 configured for gripping the stacks“P” and moving the feed path transversely to the respective stacking axis“X”, preferably in such a way that the front and rear portions of the lateral surface“P3” are left free. Each gripper 21 has a pair of jaws 22 disposed and/or configured for gripping each stack“P” at opposite portions of its lateral surface“P3” on each side of the feed direction of the stack“P” along the feed path, determined by the conveyor 20.

The jaws 22 have concave gripper surfaces shaped to match the lateral surface“P3” of the stacks“P” so as to adhere uniformly to the lateral surface“P3” of the stacks“P” and to securely support all the food products “A” making up the stacks. Preferably, the gripper surfaces are made of an elastic and/or deformable material capable of adapting to the shape of the lateral surface“P3”.

In the preferred embodiment, the conveyor 20 comprises a drum 24 that is rotatable about an axis of rotation “R” to which the grippers 21 are connected to define the aforementioned feed path according to a circular trajectory around the axis of rotation“R”.

In the preferred embodiment, the jaws 22 are configured for supporting the stacks“P” in such a way as to orient and keep the respective stacking axes“X” along the transverse direction, preferably incident upon the axis of rotation“R” along the feed path.

Also, in the preferred embodiment, the jaws 22 are movable towards and away from each other along the axis of rotation“R” of the drum 24 to grip and release the stacks“P” of food products“A”.

The machine 1 also comprises applicator means 30 acting along the feed path of the stacks“P” defined by the conveyor 20 to apply a sheet“F” of heat-sealable material, preferably rectangular or square in shape, around each of the stacks“P”.

More specifically, the applicator means 30 are configured for applying the sheet“F” into the shape of a U around each stack“P” in such a way that the first base surface“P1” of the stack“P” is in contact with a portion“F1”, preferably central, of the sheet“F”.

In the preferred embodiment, the applicator means 30 comprise a support 32 disposed at a position adjacent to the feed path of the stacks“P” and configured for positioning a sheet“F” along the feed path in such a way that each stack“P” in transit along it engages a sheet“F” with its lateral surface“P3”.

Preferably, the support 32 positions the sheet“F” along the feed path in such a way that a first side portion“F2” of the sheet“F” adjacent to the central portion“F1” moves into abutment against the lateral surface“P3” of the respective stack“P”, left free by the jaws 22 of the gripper 21 carrying it, and, in particular, moves the front portion of the lateral surface“P3”.

In a preferred embodiment, the support 32 is connected to a cutting unit configured for cutting the sheets “F” to the correct size based on the dimensions of the stacks“P” and feeding the sheets“F” to the support 32 in synchrony with the movement of the stacks“P”.

The applicator means 30 comprise a plurality of retaining elements 34 mounted on the conveyor 20 and movable, preferably around a hinge axis, between a retaining position and a disengaged position.

Preferably, the applicator means 30 comprise one retaining element 34 for each gripper 21 of the conveyor 20, associated with the respective gripper 21 and configured for retaining the first side portion“F2” of a sheet“F” abutted against a respective stack“P” when disposed at the retaining position.

In the embodiment illustrated, each retaining element 34 comprises a movable plate hinged to the conveyor 20 and rotatably movable between the retaining position, where it is abutted against a portion of the conveyor 20, of the respective gripper 21 or of the stack“P”, and the disengaged position, which is angularly spaced from the retaining position.

In practice, in the preferred embodiment of the machine 1 , a stack“P” moved along the feed path by the conveyor 20 engages a respective sheet“F” supported by the support 32 and positioned along the feed path so it is preferably stationary.

Next, a movement of the retaining element 34 from the disengaged position to the retaining position constrains the sheet“F” by pressing it between the retaining element 34 and a surface of the respective stack“P” or of the respective gripper 21.

The sheet“F” thus constrained is entrained by the movement imparted by the conveyor 20 to the respective stack“P” and is disengaged from the support 32 by following the movement of the stack“P” along its feed path. Next, another sheet“F” is fed to the support 32 to repeat the operation with the next stack“P”.

The applicator means 30 also comprise a folder 36, disposed along the feed path to intercept each sheet“F” being held by the retaining element 34 and moved by the conveyor 20 together with the respective stack“P”. More specifically, the folder 36 is disposed in such a way as to intercept a portion of the sheet“F” protruding away from the stack“P” and to make a first fold on the sheet“F” between the first side portion“F2” and the central portion“F1” in such a way that the central portion moves to a position where it covers the first base surface“P1” of the respective stack“P”.

Preferably, the folder 36 is fixed and is defined by a shoulder facing the feed path and the first fold is accomplished by the movement imparted by the conveyor 20 to the stack“P” relative to the folder 36.

Preferably, the applicator means 30 also comprise a folding gripper 38 configured for making a second fold on the sheet“F” to form the sheet into a U shape around the respective stack“P”.

In the preferred embodiment, the folding gripper 38 is mounted on a support 39 movable towards and away from the conveyor 20 and is configured for straddling each stack “P” and pressing a second side portion“F3” of the sheet“F” flat against the lateral surface“P3” of the stack“P” to form the second fold between the central portion“F1” and the second side portion“F3”.

The folding gripper is illustrated in Figures 2 and 3, where the dashed lines represent it in a first use configuration, spaced from the conveyor 20, and the solid lines represent it in a second use configuration where it presses the second side portion“F3” flat against the respective stack“P”. The folding gripper 38 is also configured for picking up the stack“P” from the conveyor 20 in the release station“S4” and moving it away from the conveyor 20.

In the preferred embodiment, the folding gripper 38 is configured for gripping the stack“P” in the release station “S4” where it is oriented according to a first orientation in which a top opening of the U-folded sheet “F” faces towards the conveyor 20, and in particular towards the axis of rotation“X” of the drum 24, and rotating the stack“P” in such a way as to dispose it according to a second orientation in which the top opening does not face towards the conveyor 20 and preferably faces towards the processing means downstream, as illustrated in Figure 4.

The machine 1 comprises sealing means 40 acting on the sheet“F” folded into a U shape around the stacks“P” from the conveyor 20.

The sealing means 40 comprise a sealing gripper 42 configured for making a first seal, preferably a fin seal, joining together the end edges “F4” of each sheet “F” in such a way as to change the “U” shaped configuration into a tubular configuration around the respective stack“P” of products“A”, illustrated in Figure 4.

The end edges“F4” are defined by the apices of the“U” formed by the sheet“F” which are sealed together in such a way as to create the first seal flat against the second base surface“P2” of the stack“P”.

Preferably, the sealing gripper 42 is configured for gripping the end edges “F4” while making the first seal and is coordinated with the folding gripper 38 in order to receive from it the sheet“F” and, through it, the stack“P”. Further, the sealing gripper 42 is configured for moving the sheet“F” and the stack“P”, held by the end edges“F4”, away from the folding gripper 38, preferably towards the sealing means following, illustrated in Figure 4, where they are generically labelled 43 and more in detail in Figures 5A to 5C.

The sheet“F”, once folded into the shape of a tube after the first seal, is wrapped around the stack“P” and in abutment against it at the first and second base surfaces“P1” and“P2” and defines two opposite openings at opposite ends of the lateral surface“P3” of the stack“P”.

The sealing means 40 and, in particular, the sealing means 43 following them, comprise first and second sealing means 44 and 46 configured for making a second and a third seal, preferably fin seals, on opposite sides of the lateral surface“P3” of each stack“P” in such a way as to occlude the two openings described above to form a hermetic wrapping containing the plurality of food products“A”.

Preferably, the first and second sealing means 44 and 46 are configured for orienting the second and third seals in a common plane parallel to the first and second base surfaces“P1” and“P2” and to the positioning plane of the first seal.

In a preferred embodiment, the sealing means 40 are also configured for pressing the fin edges of the first, second and third seals flat against the body of the wrapping defined by the sheet“F”.

The machine 1 also comprises pneumatic means 50 acting in conjunction with the sealing means 40 to obtain an at least partial vacuum inside the hermetic wrapping defined by the sheet“F” and, preferably, creating a controlled atmosphere in the hermetic wrapping, for example a nitrogen rich atmosphere, to improve the shelf life of the food products“A”.

Preferably, the pneumatic means 50 comprise a suction pipe 52, which acts in conjunction with the first sealing means 44, is configured for extracting air and can be translated from an engaged position where it is inserted in one of the openings of the sheet“F”, when the latter is folded into a tubular configuration, and a disengaged position where it is disengaged from the opening.

Preferably, the suction pipe 52 has an elongate shape in plan transverse to its internal span.

The elongate shape extends in the same direction as the second seal, from whose opening the suction pipe 52 is configured to extract air prior to making the seal itself. The suction pipe 52 also has side guide hollows configured to facilitate folding the sheet“F” before or while making the second seal.

Preferably, the pneumatic means 50 comprise a shaping element, not illustrated, acting in conjunction and coordinated with the first sealing means 44 and with the suction pipe 52.

To remove air from the hermetic wrapping before the second seal is made, the suction pipe 52 is inserted into one of the opposite openings of the tubular sheet“F”.

The first sealing means 44 are configured for pressing the sheet“F” flat against the suction pipe 52 from top and bottom.

At the same time, the shaping element is configured for pressing the sheet “F” against the suction pipe 52 from the side.

Together, the first sealing means 44 and the shaping element allow at least partly eliminating the gaps between the suction pipe 52 and the openings in which it is inserted, so as to effectively extract air from the wrapping to create an at least partial air vacuum.

Preferably, the shaping element has opposite abutment surfaces shaped to match the side guide hollows of the suction pipe 52 and is configured for making, in conjunction with them, a fold on the sheet“F” preparatory to sealing the opening.

Similarly, the first sealing means 44 are configured for making a further seal on the sheet “F”, preparatory to sealing the opening, before the second seal is made.

To prevent or reduce unwanted penetration of air, the first sealing means 44, the suction pipe 52 and the shaping element are movable in coordination with each other to make the second seal during or immediately after moving the suction pipe 52 from the engaged position to the disengaged position.

In the embodiment in which the machine 1 is configured to feed gases back in to form a controlled atmosphere inside the hermetic wrapping, the pneumatic means 50 comprise a feed pipe 54, similar to the suction pipe 52 and configured for feeding a gas in through the other of the two openings.

In this embodiment, the second sealing means 46 are similar to the first sealing means 44 and the pneumatic means 50 comprise a further shaping element, similar to the one described above, acting in conjunction with each other and with the feed pipe 54 in the same way as the first sealing means 44, the suction pipe 52 and the shaping element act in conjunction with each other.

Another object of this description is a method for the hermetic packaging of food products and which can be implemented by the machine 1 described above.

The method comprises a preliminary step of preparing a plurality of food products“A” in a stack“P” configured as described above and illustrated in Figure 1.

Preferably, the stack“P” is set in a stacked configuration in a containing seat 14 of a conveyor belt 12 like the one described above.

Next, the stack“P” is advanced on the conveyor belt 12 while keeping the food products“A” disposed in a stack, as illustrated in Figures 2 to 4.

According to the method of this description, the stack “P” is then transferred by the conveyor belt 12 to a conveyor 20, preferably similar to the one described above, by a transfer element 16 of the type described above, as illustrated in Figures 2 and 3.

Preferably, the step of transferring is carried out in such a way that the carriers 17 of the transfer element 16 grip the stack“P” by portions of the lateral surface“P3” thereof, disposed between successive pairs of teeth 13 of the conveyor belt 12, preferably the front and rear portions described above.

Next, the method comprises a step of moving the stack“P” along a feed path in a direction transverse to the stacking axis“X”. Preferably, the feed path is circular.

Preferably, the step of moving the stack“P” is carried out by a conveyor 20 of the type described above, in such a way that each gripper 21 of the conveyor 20 grips a respective stack“P” by opposite portions of its lateral surface“P3”.

Further, the grippers 21 of the conveyor 20 and the carriers 17 of the transfer element 16 grip the stacks“P” by different portions of their lateral surface“P3”.

Looking in more detail, each gripper 21 of the conveyor 20 grips the respective stack“P” in such a way as to leave the front and rear portions of its lateral surface“P3” free.

During the step of moving the stack“P”, the method comprises a step of wrapping a sheet“F” of heat-sealable material, preferably like the one described above, into the shape of a U around the stack“P” in such a way that the first base surface“P1” of the stack“P” is in contact with a central portion“F1”of the sheet“F”, defining the bottom horizontal portion of the U shape. This step is illustrated in Figures 2 to 4.

The step of wrapping is accomplished by placing opposite side portions “F2” and“F3” of the sheet“F”, adjacent to its central portion“F1” against respective intermediate portions of the lateral surface“P3” of the stack“P” interposed between the grippers 21 , preferably disposed at 90° relative to the grippers 21 around the stacking axis“X”.

The intermediate portions are preferably defined by the front and rear portions described above.

Preferably, the step of wrapping the sheet“F” comprises the steps of preparing the sheet“F” along the feed path of the stack“P”, in such a way that the front portion of the lateral surface“P3” comes into contact with the first side portion“F2” of the sheet“F”, and blocking the first side portion “F2” against the front portion.

Preferably, the sheet“F” is held in a predetermined position along the feed path by means of the support 32 described above. Further, the step of blocking is carried out by a retaining element 34 described above.

In an embodiment, the method comprises, before the step of wrapping, a step of cutting the sheet“F” to the required size and positioning the sheet “F” at the correct position on the support 32 along the feed path.

Preferably, the step of wrapping the sheet“F” comprises the further steps of making a first fold on, or pressing the sheet“F” flat, to dispose the central portion“F1” thereof so it covers the first base surface“P1” of the stack“P” and making a second fold on, or pressing the sheet“F” flat, to dispose the second side portion“F3” so it covers the rear portion of the lateral surface“P3” of the stack“P” in order to obtain the U shape of the sheet“F”, as described above.

Preferably, the first fold is made using a fixed folder 36 like the one described above, disposed along the feed path of the stack“P”.

Further, the second fold is preferably made by pressing the second side portion“F3” of the sheet“F” using the folding gripper 38 described above.

In the embodiment illustrated, the stack“P” and the sheet“F” reach the release station“S4” disposed in such a way that the end edges“F4” of the sheet“F” are directed towards the axis of rotation“R” of the drum 24.

At the release station“S4”, the method comprises a subsequent step of removing the sheet“F” and the respective stack“P” from the gripper 21 which has moved them along the feed path.

In the preferred embodiment, the step, of removing is carried out by the folding gripper 38 by gripping the sheet“F” and the stack“P” while making the second fold.

Preferably, the step of removing is accomplished by a rotational movement such that the end edges“F4” of the sheet“F” are disposed and/or kept away from the folding gripper 38 to move them away from the gripper 21 (and from the axis of rotation“R”) and preferably rotate them towards the sealing gripper 42 described above so as to present them for a subsequent step of sealing.

Next, the method comprises a first step of sealing the end edges“F4” of the sheet “F” to define its tubular configuration around the stack “P” already described above, preferably using the sealing gripper 42. This step is illustrated in Figure 4.

The first seal is made at the second base surface“P2” of the stack“P”. Further, the first seal is a fin seal and comprises a subsequent step of pressing its edge flat against the rest of the sheet“F”.

Preferably, the first step of sealing comprises gripping the end edges“F4” with the sealing gripper 42 to make the seal and then moving the sheet“F” and the stack“P” with the sealing gripper 42 holding the end edges“F4” while the folding gripper 38 releases the sheet“F” and the stack“P”.

Next, the method comprises making a second and a third seal on opposite ends of the sheet“F” in the tubular configuration in such a way as to close its two openings and to form a hermetic wrapping that completely seals the stack“P” of food products“A” in the sheet“F”, as illustrated in Figures 5A to 5C.

More specifically, the second seal occludes a first of the two openings and the third seal occludes the second of the two openings.

Preferably, the first and second seals are made using the first and second sealing means 44 and 46, respectively, as described above.

The second and third seals are made at the aforementioned opposite portions of the lateral surface“P3” of the stack“P” and are preferably oriented parallel to each other and perpendicularly to the first seal.

The second and third seals are also fin seals and preferably each comprise a subsequent step of pressing the respective edges flat.

In the preferred embodiment, the method of this description comprises, between the second and the third step of sealing, a step of extracting air through the second of the two openings to create an at least partial vacuum effect in the hermetic wrapping.

Further, after the step of extracting air and before the step of making the third seal, the method of this description preferably comprises a step of feeding a gas back in through the second of the two openings in order to create a controlled atmosphere in the hermetic wrapping.

Preferably, the step of extracting and/or the step, of feeding back in are carried out by the pneumatic means 50, described above, in coordination with the sealing means 40.

Figure 6 shows the stack“P” wrapped in the sheet“F” using the machine 1 following the method described above.

In an embodiment not illustrated, the end edges“F4” joined by the first seal might also be disposed at a different position from the one illustrated in Figure 6: for example, they might be shifted laterally relative to the second base surface P2. In this case, the first base surface“P1” of the stack“P” is in contact not with a central portion of the sheet“F” folded into a U shape but with a portion of the sheet“F” that is further to one side.

This invention achieves the preset aim by providing a packaging machine and method alternative to those of the prior art.

Advantageously, the wrapping obtained adheres to the product in a way that creates a pleasant aesthetic effect and at the same time reduces the overall dimensions of the final package compared to the prior art. This allows obtaining a wrapping line which can also make multiple packages consisting of a plurality of individual packages wrapped in this way, of more compact size for easier handling and considerable savings in wrapping material, not only for the individual packages but also for the multiple packages containing a plurality of wrapped packages.

Moreover, the position of the second and third seals along portions of the lateral surface of the stack of food products introduces a mode of packaging suitable for arranging the products in the package in potentially novel ways to make their presentation more effective.