ES2492522T3 - Drilling unit and packaging method of a product with said drilling unit - Google Patents

Abstract

Drilling unit, comprising: - a rotary reinforcement roll (34), - a rotary perforation roll (33), and - a frame (30) in which the reinforcement roll (34) and the perforation roll (33 ) are arranged with respect to each other, the piercing roll (33) being arranged to rotate independently of the reinforcing roll (34), characterized by the fact that the drilling unit is arranged in one of the following arrangements: - the roll The drilling guide (33) is equipped with a first guide (57) and a second guide (58), the first and second guides (57, 58) being arranged at opposite side ends of the drilling roll (33) and - the roll of perforation (33) is arranged in the frame (30) to make the first and second guides (57, 58) of the perforation roll (33) rotate against the reinforcement roll (34), so that the first and second guides (57, 58) of the drilling roll (33), which are mounted on bearings ( 43, 44), can rotate with respect to the perforation roll (33) or - the reinforcement roll (34) is equipped with a third guide and a fourth guide, the third and fourth guides being arranged on opposite side ends of the roll of reinforcement (34), and - the reinforcement roll (34) and the perforation roll (33) are arranged in the frame (30) to make the third and fourth guides of the reinforcement roll (34) rotate against the roll of drilling (33), so that the third and fourth guides, which are mounted on bearings, can rotate with respect to the reinforcement roll (34) or - the drilling roll (33) is equipped with said first and second guides and the reinforcement roll (34) is equipped with said third and fourth guides, respectively, and - the reinforcement roll (34) and the perforation roll (33) are arranged in the frame (30) to make the first and second drilling roll guides (33) rotate against the third and fourth guides of the reinforcement roll (34), so that the first and second guides of the perforation roll (33) and the third and fourth guides of the reinforcement roll (34), respectively, which are all mounted on bearings, can rotate in relation to the perforation roll (33) and the reinforcement roll (34), respectively.

Description

DESCRIPTION

Drilling unit and packaging method of a product with said drilling unit.

[0001] The present invention relates to a drilling unit and a method for packaging a product using said drilling unit.

[0002] There are products that can be packaged in shrink film. Such packaging film consists of a plastic material that tends to contract when heated. This property is used to contract the packaging film around a product, so that it fits around it and can protect it well from its environment. In the case of natural products such as certain types of cheese, especially certain types of soft cheese (ie creamy), for example brie, the packaging applied to the product is usually opened by cutting it. The user can make such a cut either with a knife or with scissors. The goal of the user is to partially insert their finger through the opening of the packaging film to open the packaging, and then pull the film to tear it until it is open. However, because the film is tightly adjusted to the product and / or because the film used is quite hard after the shrinkage process, it is difficult to remove the packaging material quickly without damaging the product. When the product consists, for example, of a relatively soft and flexible material, it is sometimes impossible to avoid deformation or even damage thereof.

[0003] In addition, soft cheese and similar products are cut lengthwise, so the film must be opened transversely. However, it has been discovered that it is difficult to open the packaging in a transverse direction, so that as a result the product is frequently damaged.

[0004] Another problem that occurs specifically with the use of contractile film is that, although the latter is hard after heating, it is quite soft (ductile) and flexible before heating. In addition, the contractile film is often quite elastic in all directions, and can be torn more easily after being contracted. This makes it difficult to work such packaging, for example by making a cut in it before the film is subjected to a contraction process. These problems occur with the elastic film (or combined contractile-extensible film), and can also occur for example in the case of the packaging film.

 30

[0005] It is possible to use a perforation roll to perforate the film locally to form a perforated line in the longitudinal direction of the film. Then a label is pasted on the perforated line to seal the film. The film can then be contracted on the product. To open the packaging, the user pulls the label in the direction perpendicular to the direction of the product to open it along the perforations and pull the film to the side of the product. However, it has been discovered that such perforated line does not always open as easily as it is supposed to. Depending on the shape and / or properties of the product itself, the product may not be easily removed from the packaging when the latter is opened in this way in a transverse direction.

[0006] Food products such as cheese portions generally vary in size and shape. It may therefore be desirable to vary the perforation of the opening according to the size, shape or other characteristics of the product; and / or vary the distance between subsequently perforated openings.

[0007] It is generally difficult to work a relatively soft (ductile) and flexible packaging material (other than an extensible or shrinkable film) and provide it with an opening to allow the packaging material 45 to be later easily removed from the product. .

[0008] US2003 / 191001 discloses a drilling unit, which comprises a rotary reinforcement roll, a rotary perforation roll and a frame where the reinforcement roll and the perforation roll are arranged relative to each other. fifty

[0009] US2005 / 0209076 shows a drilling unit with a first roller having a first gear attached to it. The drilling unit also has a second roller with a second gear attached to it. By means of the first and second gears, the rotation of the first roller is transmitted to the second roller. The operating paths are fixed to the extremities of the second roller. The second roller is born by an axis through these 55 pathways. These pathways exert pressure on the corresponding surface of the first roller to precisely position the first and second rollers relative to each other. The pressure rollers provide the proper tension of the pathways against the first roller. In this particular arrangement, the first and second rollers rotate with the same speed and cannot rotate independently.

 60

[0010] It may be desirable to provide a packaged product whose packaging material can be easily removed, so that the product can be easily removed from the packaging.

[0011] It may be desirable to provide a method and device for packaging products, and / or provide a packaged product where one or more of the above problems and / or other problems affecting the current state of the art are / are solved.

[0012] It is an object of the present invention to provide a perforating unit, as well as a method and device with the help that one or more openings can be made in a flexible and relatively soft packing material.

 5

[0013] For this purpose, a drilling unit must be provided in which one or more of the above problems and / or other problems affecting the current state of the art are avoided, and which is especially suitable for drilling one or more openings in the packaging material, such as a film for packaged cheese, or other types of film, in a flexible manner.

 10

[0014] For this purpose the present invention provides a drilling unit, comprising:

- a rotary reinforcement roll,

- a rotary punch roll, and

- a frame where the reinforcement roll and the perforation roll are arranged relative to each other, 15

the perforation roll being arranged to rotate independently of the reinforcement roll,

characterized by the fact that

The drilling unit is arranged in one of the following provisions:

 twenty

- the drilling roll is equipped with a first and second guides, the first and second guides arranged at opposite side ends of the drilling roll and

- the perforation roll arranged in the structure to make the first and second guides of the perforation roll rotate against the reinforcement roll,

so that the first and second drill roll guides, which are mounted on bearings, can rotate 25 with respect to the drill roll

or

- the reinforcement roll is equipped with a third guide and a fourth guide, the third and fourth guides are arranged at the 30 opposite side ends of the reinforcement roll, and

- the reinforcement roll and the perforation roll are arranged in the structure to make the third and fourth guides of the reinforcement roll rotate against the perforation roll,

so that the third and fourth guides, which are mounted on bearings, can rotate with respect to the reinforcement roll 35

or

- the drilling roll is equipped with the first and second guides and the reinforcing roll is equipped with the third and fourth guides, respectively, and 40

- the reinforcement roll and the perforation roll are arranged in the structure to make the first and second guides of the perforation roll rotate against the third and fourth guides of the reinforcement roll,

so that the first and second guides of the perforation roll and the third and fourth guides of the reinforcement roll, respectively, which are all mounted on bearings, can rotate in relation to the perforation roll and the reinforcement roll, respectively. Four. Five

[0015] Thus, a drilling unit is provided comprising a rotary reinforcement roll, a rotary perforation roll and a frame where the reinforcement roll and the perforation roll are mounted relative to each other so that the perforation roll can rotate independently of the reinforcement roll. Because the reinforcement roll and the perforation roll can rotate independently of each other, it is possible to rotate the two at 50 different speeds. With such a drilling unit, the reinforcing roll can for example rotate at the same speed as the packaging material therein, while the speed of the drilling roll can vary, for example, between this speed, starting at an initial position during the operation of drilling, and a second different speed, in which the drilling roll (after completing the drilling operation) can continue rotating in a waiting position until the next drilling operation. The drilling roll can also remain motionless in its waiting position. In this way, for example, the distance between two successive drilling operations can be varied at will. When the perforation roll can only be rotated according to the reinforcement roll as usual, and when the perforation roll and the reinforcement roll rotate at the same speed as the packing material that moves between them, the distance between two operations of successive drilling is equal to the circumference of the drilling roll, if it is equipped with a single punch, or is equal to 60 distance along the circumference between two successive drilling operations on the circumference of the drilling roll if this The latter is equipped with two or more punches. In the case of conventional drilling units, therefore, the distance between two successive drilling operations is fixed by the characteristics of the drilling roll. The present invention provides a more flexible drilling unit, with which, for example, the distance between two successive drilling operations can be varied without interrupting the work. The distance between two drilling operations can also be varied between a first roll,

using for example a first fixed distance, and a second run, using for example a second fixed distance, without having to replace the drilling roll for example with a drilling roll with a different number of punches and / or a different circumference.

[0016] In some of the embodiments of the present invention, the perforation roll is equipped with at least one punch, which is installed in the perforation roll and is used to make an opening in the packing material, starting by an initial position where the packing material is introduced at its feeding speed.

[0017] The introduced packaging material can be equipped with one or more cover elements. The punch unit 10 can be used to drill an opening through the packing material to the cover element. The resulting opening makes it possible, for example, to tear the packing material in a first direction and then in a second direction which can be, for example, the opposite of the first direction which is essentially transverse, in order to be able to remove the packaging material from the product at least partially.

 fifteen

[0018] The product may be for example a portion of cheese, especially a portion of soft cheese (ie creamy).

[0019] The packaging material may be for example a shrink film, an extensible film, a combined elastic film, or a skin-type packaging film. A packaged product can be manufactured, which is packaged in a packaging material, such as a shrink film or an extensible film, to which at least one covering element has been applied and in which at least it has been made. an opening in place of the covering element, essentially without making a corresponding opening in the covering element, so that the opening or openings is / are only formed in the packing material, to tear the packing material in a first direction and then in a second direction to remove it from the product at least partially. The shape of the opening or openings makes it possible to tear the packaging and extract the product easily, so that the product can be easily removed from its packaging.

[0020] The packaging operation can be combined with other methods to make a completely online packaging process possible. In some other embodiments, the packaging is performed offline, that is, the application of cover elements (such as labels, for example) and the formation of openings are performed separately from the packaging of the products. In the case of an off-line packaging process, the packaging material with the covering elements applied to it is stored in an intermediate roll.

[0021] The cover element may be a label, which may be a self-adhesive label or an adhesive, or a label of a different type, but the embodiments in which the cover element is a longitudinal band are also possible. In addition, the coverage element can be applied to either a treated film or an untreated film. The opening is then formed in the place of the covering element, using for example a drilling unit or a cutting laser. The presence of the covering element can make the film less ductile locally, so it will be easier to place the film and form an opening therein in the proper position with the help of the unit used. The opening made in the packaging can therefore have a suitable shape that allows the user to easily open the product by tearing it and removing the packaging from it. Thus, the opening can be an elongated and substantially uninterrupted (continuous) opening. In some other embodiments, a series of perforations or smaller openings are made, which together form a perforated line, along which the packaging can be easily torn. Four. Five

[0022] In addition, the packaging material used to package the product can completely cover the latter, but other types of packaging are also possible and all are based on the packaging possibilities as defined herein. For example, it is possible to use the packaging material to seal another packaging material, for example to seal a plastic container, a tray or a base support, for example in the case of a deep drawing machine or a sealing machine higher.

[0023] The covering element adheres to the packaging material with the aid of an adhesive, such as glue, for example, and is then used as a reference point to pierce an opening in the packaging material. The opening is preferably perforated through the packing material, to the covering element, while the latter remains essentially intact. As a result, not only the cover element retains its aesthetic appearance, but also the product can be sealed tightly in the packaging, despite the presence of an opening (naturally as long as the cover element remains adhered to the packaging film).

 60

[0024] When the cover element has been applied and the opening has been formed, one or more products can be introduced into the packaging material, and the latter is then arranged around the product or products. After that, the packing material is sealed, so the product assembly and packing material are prepared for another treatment.

 65

[0025] When the packaging material is a shrink film, it can also be treated by heating the

combination of the product and the film so that the film contracts on the product.

[0026] Any type of contractile film can be used as the packaging material, for example a barrier film (which is a contractile film designed to form a barrier against air and gases) or a film without special barrier properties, a monolayer film, a multilayer film, a laminated film, a co-extruded film, a coated film and / or a metallized film. The material for the cover element can be chosen according to the type of packaging material used. For example, if a barrier film is used as a packaging material, it is better to provide the cover element with a barrier. This can improve the watertight nature of the packaging.

 10

[0027] As mentioned above, the contractile film is relatively soft and flexible, which makes it difficult to work. Substances that can be used to make the packaging material include an ethylene-vinyl alcohol copolymer (EVOH), an ethylene-vinyl acetate (EVA) copolymer, polypropylene, polyethylene, polyvinyl chloride, nylon, polyamide, polyester and several copolymers. These materials can be soft and flexible, for example when the packing material is between 5 and 35 µm thick. fifteen

[0028] The following steps can be applied:

- transport a band of packaging material to a cover element applicator unit,

- apply a series of coverage elements to the band of packaging material by the applicator unit of 20 coverage element,

- pass the band of packaging material provided with cover elements along a drilling unit, and

- pierce an opening by means of the drilling unit but only in the packaging material, up to the cover element, each time one of the cover elements passes.

 25

[0029] In this way, a large number of cover elements with one or more openings can be applied efficiently and quickly. In addition, the distance between successive coverage elements (eg labels) can be chosen at will, so that the required cutting length can be guaranteed. The cutting length depends for example on the shape and / or size of the product being packaged, on the interval between the products needed for the correct operation of the packaging machine, on the dimensions of the packaging tool, 30 of any identification point on the packaging material, etc. or else the cutting length can have, for example, a predetermined value.

[0030] The cutting length can be determined manually, for example before packing several products with known dimensions, but can also be determined based on an electrical signal generated by an external scanner. The external scanner can for example scan the products when they are introduced, and the optimal cutting length can then be calculated and transmitted separately for each product, depending on the scanned image.

[0031] The opening or openings that are / are made in the packing material can have many different shapes.

In the case of elongated products, it is usually preferred to make the location of the opening essentially perpendicular to the longitudinal direction of the product. This is because the packaging can then be grabbed by the opening and opened in the longitudinal direction. If the packaging is pulled in the longitudinal direction until it is opened, it can be opened by tearing a relatively large length before reaching a sealing line. The sealing lines can be even harder than the rest of the packing material, so that in these it is particularly difficult to tear the packaging until it is opened. It is possible to provide the opening with tear-off tabs at a couple of points to facilitate tearing of the package until it is opened and / or to help the user to tear the package at the appropriate points.

 fifty

[0032] In all packages known so far, the openings have been made so that the packaging can only be torn in one direction. However, it is possible that the opening made only in the packaging material is used not only to tear the packaging in a first direction, but also to facilitate tearing of the packaging in a second essentially opposite direction, to be able to remove the material Product packaging more easily, or even more easily than the other way around. For example, the opening may be provided with two different series of tear tabs. The first set of tear tabs is formed to tear the packaging in a first direction, while the second set is formed to tear the packaging in a second direction. The first set of tear tabs can be formed for example by several tear lines perpendicular to the opening, in a first longitudinal direction, while the second set is then formed by several tear lines perpendicular to the opening in the longitudinal direction 60 opposite.

[0033] The method according to the present invention may result in the formation of one or more openings in the packaging material. When two or more openings are formed, this can be done in the form of a row of perforations, arranged one after the other. A perforated line can be formed in the packing material 65 in this way.

The size of the perforations and the distance between the openings can then be chosen so that the perforated line opens when the cover element is removed.

[0034] As mentioned above, the opening made in the packaging material in certain embodiments is essentially perpendicular to the longitudinal direction of the film strip. In some other 5 embodiments, however, it is better for the opening to extend essentially in the longitudinal direction. In another embodiment, the cover element has an area without adhesive, so that a tongue protruding from the packaging is formed, with the aid of which the cover element can be removed from the packaging material. The user can grab the first tongue on the product still packaged, and (when he or she gradually pulls the cover element by its tongue at least partially by removing it from the packaging material) part of the packaging material will also be removed, thus the packaging it is possible to tear from for example the ends of the opening or the tabs of the opening.

[0035] The packaging unit can be integrated with the other units of the device, so that a completely online packaging process can be achieved. In some other embodiments, the application of the cover elements (eg labels) and the formation of the openings are carried out separately from the product packaging, in an off-line packaging process. The in-line packaging process, in which the packaging material equipped with cover elements does not need to be rewound again, can make it possible, for example, to use a relatively thin packaging material with relatively thick cover elements. The fact that, in an off-line packaging process, such a fine packaging material, equipped with 20 relatively thick covering elements, has to be rolled up again, may involve the risk of an irregular roll being obtained due to the relatively large difference in thickness between sections of packaging material without any covering element and the sections of packaging material in which covering elements have been applied, the total thickness of the packaging material with covering elements being very different from the thickness of packing material alone. 25

[0036] In a preferred embodiment of the invention, the packaging material is a shrink film, and the packer has a sealing unit, especially an in-line packing sealing unit, for sealing the product in the film, and / or a heating unit, especially a retractable tunnel, to contract the packing material tightly over the product. In addition to a 30-line packing sealing unit, other sealing units, such as a conventional deep drawing machine, a top sealing machine or a skin type machine, can also be used.

[0037] In some of the embodiments of the invention, the punch of the punch unit is used to make a first opening in the packaging material, essentially without making a corresponding opening in the covering element beyond of this, and also to make a second opening, this time in the packaging material and in the covering element that is beyond it.

[0038] The drilling unit can have a first drilling component with a relatively small height, and a second drilling component with a relatively large height, so that when the drilling unit 40 performs a drilling operation with its first drilling component, only it creates an opening through the packing material, while when the second perforating component is used for drilling, an opening is created both through the packing material and through the covering element.

[0039] Another embodiment comprises a cover element applicator unit whose function is to place another (ie, a second) cover element on the packaging material after forming a ventilation opening in the cover element, being the objective of this second cover element to close the ventilation opening hermetically again. The second marker or cover element is at least partially superimposed on the first in order to cover the ventilation opening in the label. This second coverage element applicator unit can be a separate unit. fifty

[0040] In another embodiment of the invention, the drilling unit comprises a rotary reinforcing roll, a drive motor for rotating this reinforcing roll, a speed sensor both for determining the speed at which the material is introduced. packaging such as to emit a speed signal representing the feed speed, and a control unit that is coupled to the drive motor and the speed sensor, and which is used to adjust the rotation speed of the booster roll according to The speed signal received. In another embodiment, the control unit is used to produce a control signal to ensure that the speed and / or acceleration of the reinforcement roll are / is essentially the same as that of the introduced packaging material, without any delay. between these. Due to this arrangement and an encoder that can count the established steps and thus determine exactly when a cover element should be applied, the cover element can be applied to the packaging material in exactly the right position, even if the film is very ductile and flexible.

[0041] In a particular embodiment, a light reinforcing roll is used, which can be achieved by making it at least partially or essentially hollow. A reasonable weight saving can be achieved 65 by making the reinforcing roll at least 50% hollow and preferably at least 80% hollow, thus reducing its weight

even with the same extension.

[0042] In another embodiment, the two drill roll guides can rotate with respect to the drill roll itself, as they are mounted on bearings. The perforation roll can therefore rotate independently of the reinforcement roll while still maintaining the required distance, due to the presence of the 5 guides.

[0043] In another embodiment, the drilling unit comprises a rotary reinforcement roll and a perforation roll that can rotate considerably independently of the reinforcement roll, wherein the perforation roll has a central part and a perforation part. installed so that it can move 10 laterally with respect to the central part, just as it can be fixed in any lateral position in relation to the reinforcement roll. This arrangement can also keep the weight of the drill roll low and make it easy to adjust the position of the punch to form openings in the right places in the lateral direction.

[0044] In some embodiments of the invention, the perforation roll, when drilling, rotates at exactly the same speed as the reinforcing roll, which in turn rotates at exactly the same speed as the film strip. The drilling roll has an initial position. As soon as the cover element is detected just above the perforation roll, the latter begins to rotate at exactly the same speed as the reinforcement roll. The film is then perforated to form an opening under the covering element. When the drilling tool has just passed the reinforcement roll, it begins to return to its initial position, but at a higher speed, and then stops there, waiting for a new signal to rotate again. The initial position can also be called the waiting position. In some embodiments of the invention, the perforation roll has a single perforating tool in its circumference, and the initial position of the perforation roll preferably corresponds to a single predetermined rotational position of the perforation roll, where the perforating tool can be prepared to execute a drilling operation. In some embodiments, the drill roll is equipped with two or more drill tools, located in different positions along the circumference of the drill roll. These drilling tools can be used in a fixed sequence, for example one after the other. The initial position of the perforation roll preferably corresponds to a posterior rotational position of between a number of different predetermined rotational positions of the perforation roll, where the next drilling tool in the assembly can always be prepared to execute the next drilling operation. The drilling roll can then rotate between two successive drilling operations, for example to the next rotational position, so that the drilling roll can for example be prepared for the next drilling operation in less time than in the case of having a only drilling tool, and thus be able to achieve for example a higher transit speed. 35

[0045] Faster rotation of the drilling roll can be achieved in one embodiment by adjusting the drilling roll with two guides, mounted on bearings. As a result, the two guides of the perforation roll can rotate with respect to the perforation roll, so that the perforation roll can rotate independently of the reinforcement roll. The latter can therefore rotate at the speed of the film strip, while the perforation roll 40 can move to its initial initial position faster, for the next drilling operation after the previous one has been completed. Due to the presence of the guides, the required interval can be maintained, so that the perforation roll is always pressed against the reinforcement roll with an appropriate force for drilling. In another embodiment, the reinforcement roll is equipped with two guides, which are mounted on bearings, so that they can rotate with respect to the reinforcement roll. This is an alternative way to make the perforation roll rotate independently of the reinforcement roll.

[0046] In some of the embodiments, the perforation roll and the reinforcement roll are moved by two different drive motors, each with its own control unit. The control unit of the reinforcement roll is used to regulate the drive motor of the reinforcement roll in such a way that the speed and / or acceleration of the reinforcement roll are / is essentially the same as that of the introduced packaging material, such as described above. The punch roll control unit can be used to regulate the drive of the drill roll in such a way that (during the drilling operation) its speed and / or acceleration matches that of the packaging material introduced, and (after if this operation has been completed) the drilling roll continues to rotate to its initial position at a higher speed, for the next drilling operation. In another embodiment, these two control units are integrated to form a single control unit, which both drive motors can regulate.

[0047] In another embodiment, the piercing roll contains at least one magnetic part for detachable attachment of a piercing component to the surface of the piercing roll. As a result, if another piercing component (for example one having a different shape or a different height) has to be used, the piercing roll must not be completely removed, since it is sufficient to simply exchange the piercing component itself.

[0048] A device as described hereinafter may comprise: 65

- a feed conveyor to introduce a series of products,

- a scanner configured to detect at least one of the relative positions, types and dimensions of the products in the feed conveyor, and to emit a detector signal representing the detection results, and

- control means that use the scanner's detector signal to determine how much packaging material is needed to package each product.

[0049] Alternatively such device comprises:

- a feed conveyor to introduce a series of products, 10

- a scanner configured to detect at least one of the relative positions, types and dimensions of the products in the feed conveyor, and to emit a detector signal representing the detection results, and

- control means using the scanner's detector signal to determine the desired properties, in particular the position, shape and / or dimensions, of the openings that must be made in the packaging material. fifteen

[0050] As another alternative, such a device comprises:

- a feed conveyor to introduce a series of products,

- a scanner configured to detect at least one of the relative positions, types and dimensions of the 20 products in the feed conveyor, and to emit a detector signal representing the detection results, and

- control means that use the scanner's detection signal to determine the desired positions where the cover elements should be applied to the packaging material.

 25

[0051] The feed conveyor is for example a continuous conveyor belt, a series of articulated supports or containers such as trays, or a chain of chain film.

[0052] Any type of scanner can be used, such as an optical scanner, and the unit can also consist of a set of scanners, to discern the products for example at different angles or at different positions. The optical scanners used may consist, for example, of one or more cameras coupled to the control units (load coupled devices in the form of CCD cameras). When, for example, the packaging machine is used to package products of different shapes and sizes, the cutting length of the packaging material can be identified for each product introduced, this being the length of packaging material needed to pack the product in question . Alternatively or additionally, the point at which a covering element should be applied to the packaging material can be identified and / or an opening must be formed therein. In addition to identifying the cutting length, the control units and the scanner can be constructed so that the required characteristics of the openings that must be made in the packing material can also be identified and even possibly determined automatically, that is, without A manual operation. Possible features of this type include position, shape and / or size of the openings (openings) in relation to the product to be packaged. When the control units (eg microcontrollers) are coupled to at least one of the other units, that is, the applicator unit of the cover element, the opening unit and the packaging unit, these units can be placed separately or together according to the detector signal emitted by the scanner.

 Four. Five

[0053] In some of the embodiments, the perforation roll and the reinforcement roll are moved by their own drive motors, which are regulated by different control units. The control unit for the booster roll can be used to regulate the drive motor of the booster roll such that the speed and / or acceleration of the booster roll are / is essentially the same as that of the introduced packaging material. , as described above. The control unit of the perforation roll can be used to regulate the drive motor of the perforation roll such that (during the drilling operation) its speed and / or acceleration are / is the same as that of the packaging material introduced , while (after the drilling operation is completed) the drilling roll is preferably moved to its initial position at a higher speed, for the next drilling operation. In another embodiment, the different control units are integrated to form a single control unit 55 that can regulate both drive motors. Other advantages, features and details of the present invention are elucidated in the following description of some preferred embodiments with reference to the accompanying drawings, where:

Fig. 1 is an exploded side view of the packaging machine for packaging various products, including the film 60 used for this purpose

Fig. 2 shows a front view of the packaging machine, without the packaging film

Fig. 3 shows a partially exploded detailed side view of the drilling unit illustrated in Figures 1 and 2, especially the actuation of its drilling roll (magnetic roll) and reinforcing roll

Figures 4a and 4b show schematic side views of the perforation roll and the reinforcement roll in their initial position A before the drilling operation, and in position B, immediately after the operation of

Perforated

Figures 5a-5d show partially exploded top views of the steps taken by the user when opening a packaged product

Fig. 6 shows a top view of a punch used to make an opening in the shrink film used to pack the product 5

Fig. 7 shows a schematic diagram of the shape of the label applied to a product illustrated in fig. 4

Fig. 8 shows a package in which a ventilation opening has been made in addition to the opening to open the package, and

Figures 9a-9h schematically show the details of some examples of appropriate openings.

 10

[0054] Fig. 1 shows a packaging machine to package a freely chosen product. In the example discussed here, the product is an irregularly shaped natural product, such as a portion of soft cheese. More specifically, the product is shaped like a cake portion that has to be packaged in a shrink film. The packaging should be such that it can be opened relatively easily and the user can remove the product packaging without requiring any tools. fifteen

[0055] The packaging machine 1 comprises: a unwinding unit 2 for introducing a contractile film strip that is wound on a roll; a coverage element applicator unit 3 (especially a labeling unit) that applies the coverage elements (especially labels) to the shrink film; a piercing unit 5 for making one or more openings in the shrink film; a feed conveyor 6 to 20 introduce the products (P) that must be packaged; an insert conveyor 7 (not shown) to place the products (P) on the contractile film; and an in-line container sealing unit 8 to seal the packaging and then contract it on the product in question.

[0056] The unwinding unit 2 of the packer 1 comprises a frame 10 fixed on a base (o) and houses a 25 unwinder roll 11. The unwinder roll 11 can rotate on bearings in the frame 10. A part of shrink film 12 is winding on the unwinding roll 11. This shrink film 12 is generally 5-35 µm thick. If a different film is used, it should generally have a thickness of 5-150 µm and preferably 5-80 µm. Other rolls 14-21 are also mounted on the frame 10 to send the shrink film to the insertion conveyor 7 mentioned above. In the case illustrated here, these rolls 14-21 are not driven. The shrink film 30 is driven by the movement of the continuous belt of the insertion conveyor 7. The latter carries the shrink film band 13 out of the unwinder roll 11 and transports it first through the labeling unit 3 and then through the punch unit 5. The insert conveyor is for example a conveyor belt, a series of articulated brackets or containers such as trays, or a chain of film. 35

[0057] The labeling unit 3 is also mounted on the frame 10. The labeling unit 3 contains several labels that have been applied to a roll of support material 20. A dispensing device 18 can firmly glue these labels on one side of Band 13 of contractile film. The labeling unit 3 is coupled here to a central control unit 25 and issues a label each time it receives a 40-label dispensing signal from this control unit 25.

[0058] The drilling unit 5 is composed of a frame 30 in which several rolls are mounted in a rotating manner. As shown in more detail fig. 2 and 3, the frame comprises two vertical structure components 31, 32, between which an upper roll 33 and a lower roll 34 are mounted. The lower roll 34, called the reinforcing roll 34 of the drilling roll, is cylindrical in shape. and it is essentially hollow inside to minimize its weight. The reason for this is that the reinforcing roll 34 may have to react very quickly to variations in the feed rate of the shrink film band 13, and this must therefore be able to perform a large acceleration or deceleration. In an alternative embodiment, the reinforcing roll 34 is essentially solid. fifty

[0059] The reinforcing roll 34 can be equipped with guides 35, 36 at its two opposite side ends. The guides 35, 36 are located near the reinforcing roll 34 and are made of a hard material, preferably a metal, as is the reinforcing roll itself. In some other embodiments, the reinforcing roll is smooth and the separate bearing rings are omitted. The assembly formed by the reinforcement roll and its guides is equipped with two shafts 37, 38, arranged in the vertical parts 31, 32 of the frame 30 so that they can rotate on their bearings 39, 40.

[0060] The reinforcing roll 34 is moved by a servomotor 50 whose motor shaft 51 is coupled to the reinforcing roll 34 by a transmission belt 52, such as for example a toothed belt. The servomotor 50 is regulated by a 60 coding roll, comprising a tachymeter and an encoder, shown in fig. 1 as article 17. This coding roll determines the momentary speed of the shrink film band 13 when it passes through it and transmits a signal to the servomotor 50 representing the measured momentary speed, doing this either directly or through the control mechanism mentioned above. In this way, the reinforcing roll 34 can for example copy the variable speed of the shrink film band 13 within a relatively small range 65.

[0061] The upper roll 33, located on the drilling unit 5, also called the drilling roll or magnetic cylinder 33, is designed to carry the punch, which is used to make an opening in the shrink film. The perforation roll 33 is composed of an elongated central part 42, which is rotatably mounted on the frame 30 with the help of a bearing 28. The elongated central part 42 has a roll 54 in the middle. This roll 5 carries a punching tool that can make openings in the packing material, as described later.

[0062] The central part 42 is coupled to two other guides 57, 58 through the bearings 43, 44, respectively. These guides are also made of hard material. The guides 57, 58 pass through the bearings 10 mentioned above 43, 44 against the lower guides 35, 36 of the reinforcement roll 34. These ensure that a constant (small) interval is maintained between the outer wall of the reinforcement roll 34 and the outer wall of the roll 54. To maintain this interval, two guides 29 are placed on the piercing roll. The guides 29 are fixed on an adjustment bridge 45, the height of which can be adjusted upwards with the help of two adjustment knobs 46, 46 '. The rolling surfaces of the guides 29 can push down the guides 57, 58 of the drilling roll, 15 thus ensuring that the drilling roll maintains the proper distance from the reinforcing roll.

[0063] The roll 54 has a width b1, shown in fig. 2, which is smaller than the width b2 of the reinforcement roll 34 placed beneath it. In addition, the roll 54 can be displaced laterally (in the direction R1 shown in Fig. 2) with the help of a fixing aid 60, so that the tip of the punch can make an opening in the band 13 of shrink film in the lateral position required along the section of the roll 42. The perforation roll 33 is moved by another servomotor 62. This servomotor 62 has a secondary axis 63, which is coupled to the perforation roll 33 by a transmission belt 64 for move it The construction illustrated here makes it possible to rotate the piercing roll 33 and the reinforcing roll 34 independently of each other. Even when the reinforcing roll is constantly rotating (although with different speeds, corresponding to the 25 speed variations of the band 13 of the shrink film), the piercing roll 33 may be motionless, or it may rotate more quickly or more slowly , while the punch 70, arranged in the circumference of the roll 54 shown in figs. 4a and 4b, can be placed in the right position at the right time with respect to the labels that have been pasted on the shrink film band 13.

 30

[0064] The piercing roll 33, or at least its roll 54, is equipped with a flexible metal sheet 71 on its surface. This metal sheet can be fixed (and removed) to the surface of the roll 54 of the piercing roll 33 with the help of some magnets, which are not shown. The blade 71 is equipped with at least one punch (a piercing tool or a knife) 70, which can be for example a piercing component in the form shown in fig. 6. In the embodiment illustrated herein, the punch 70 consists of an elongated and substantially undulated portion 119, with several protrusions 116, 117 and ends 112. As described later in more detail, the punch 70 can make a corresponding opening in the contractile movie. The protrusions 116, 117 mentioned above are used to form the corresponding tear tabs 106, 107.

 40

[0065] When the band 13 of the introduced shrink film has left the piercing unit 5, it is driven on several rolls 19-21 and passes a number of photocells 75. The photocells 75 can detect the presence of a label in the mobile band 13 shrink film. The contractile film is then transported to the insertion conveyor 7 mentioned above.

 Four. Five

[0066] The insert conveyor 7 has a continuous conveyor belt 78, which can move rolls, some of which are not shown here (therefore, only the left roll 79 is illustrated in Fig. 1). The shrink film band 13 is placed on the continuous conveyor belt 78, where it moves at the same speed towards the in-line container sealing unit 8, mentioned above. As this can be a conventional in-line container sealing unit, it is not shown in the figures. The function of the in-line container sealing unit 50 is to seal the film placed on the product and then direct the product with its sealed film in a retractable tunnel. The latter contains an oven in which hot air is used to cause the shrink film band 13 to contract to such an extent that it fits the product.

[0067] Finally, the feed conveyor is of the conventional type and has a continuous conveyor belt 55 that moves in several rolls 81 and 82 and on which the products (P) are introduced to be packaged individually or otherwise. Fig. 1 only shows a few products (P) to keep the drawing simple, but there may of course be a much higher number of them in practice.

[0068] During operation, the unwinding unit 2 feeds a strip 13 of shrink film to the punch unit. The coding roll mentioned above 17 (with a tachymeter and an encoder) determines the speed of the shrink film band 13 moving along it and sends an appropriate signal to the control unit 25 and / or the servomotor 50 of the booster roll 34. The servomotor 50 now ensures that the booster roll 43 rotates essentially at the same speed. This means that the speed of the surface of the reinforcing roll, whose surface is in contact with the shrink film band 13, is essentially the same as the speed of the shrink film.

[0069] Flexibility is a characteristic of the shrink film, so it is not easy to guarantee a constant speed for this type of conveyor mechanism. However, it is also not necessary to guarantee a constant speed of the shrink film band 13 in the construction illustrated here, because any variation in the speed of the film band can be reproduced by the coding roll 17 (with its tachymeter and 5 encoder ) and by the booster 50 of the booster roll.

[0070] The labeling unit receives a signal at a certain time to issue a label. This signal comes from the control unit 25 and the roll 17, where there is also an encoder that measures the length in stages, the order being issued a cover element or a label. The dispensing unit 18 then emits a label 10 in a normal manner and sticks it firmly on the side 22 of the shrink film band 13 (see fig. 1). This label is schematically shown as article 26 in fig. 1. In the case of the rest of the labels 26, a control unit in the servomotor 50 calculates the cutting length, that is, the required final length of the film band needed for the product in question. As soon as this cutting length is reached, the labeling unit 3 receives a signal again to issue a label. The dispensing unit 18 then issues another label 26 and the 15 sticks firmly on the shrink film band 13.

[0071] The cutting length depends for example on the distance between the products necessary for the satisfactory operation of the packaging machine. If the products are for example portions of cheese approximately 170 mm long, and if the required distance between two successive products is for example 50 mm, then the required cutting length should be adjusted to 220 mm.

[0072] The cutting length can be set for example according to the types, shapes, sizes and relative positions of the products P present in the feed conveyor 6. For this operation, a scanner 86 can be used to detect at least one of the types, sizes and relative positions of the products P in the feed conveyor 6 and to send to the control unit 25 a detector signal representing the detected results. The control unit 25 can then determine (according to the detector signal received from the scanner 86) how much packaging material has to be used for each product during the packaging operation. The control unit 25 can be used alternatively or additionally to determine (according to the detector signal received from the scanner 86) the required characteristics (especially the position, shape and / or dimensions) of the openings to be made in the packaging material. The control unit 25 can be used alternatively or additionally to determine (according to the detector signal received from the scanner 86) the position required to place the covering elements (labels) 26 on the packaging material. The control unit 25 can be coupled to at least one of the following: the cover element applicator unit (i.e., the labeling unit 3), the opening unit (i.e., the drilling unit 5) and the unit packaging (that is, the container sealing unit in line 8), so that these units can be mounted either individually or collectively to operate according to the detector signal from the scanner 86. In the example illustrated here, the scanner 86 is a CCD camera

[0073] As soon as the photocell 85 (or other suitable sensor) located near the coding roll 17 (with its 40 tachymeter and encoder) detects a tag 26, a signal is sent to the control unit 25 and / or directly to the servomotor 62 of the perforation roll 33. The perforation roll 33, or at least the punch 70 therein, is now prepared in a predetermined initial position, for example in position A, shown in fig. 4th. The servomotor 62 now rotates the punch 70 beyond its initial position (A) to a point between the reinforcement roll and the piercing roll, also ensuring that this has been done just at the moment when a label passes the 45 combination of reinforcement roll and perforation roll. In addition, the rotation speed of the perforation roll is regulated to match the speed of the reinforcement roll and also the instantaneous movement speed of the film, this regulation based on the signal emitted by the coding roll 17 and which is representative of the instantaneous speed of the packaging machine that has been determined.

 fifty

[0074] For various issues, the speed of movement of the packaging material (film) generally varies over time. The speed of movement in which the packaging material passes the perforating unit may vary, for example because the film is being stretched somewhere, and due to the fact that an advance movement occurs when the film is treated in the packaging unit or its conveyor, for example when sealing the bars of an in-line packaging sealing machine. It is important that both rolls of the drilling unit copy this travel speed exactly.

[0075] In addition, the height h of the punch shown in fig. 4a is chosen so that only the film 13 is perforated while the label is not, or directly is not perforated. In other words, an opening (a groove or a perforated notch) is made in the film passed the label without making a corresponding opening in the label itself. The perforation roll continues to rotate to position B, shown in fig. 4b The servomotor 62 then ensures that the drilling roll rotates at a high speed to its initial position, shown in fig. 4th. The rotation speed is so high here that the punch 70 reaches its initial position again in time to execute the next drilling operation. This process is then repeated each time the band 13 of the shrink film is moved over the predetermined cut length and a new label is placed again between the reinforcement roll and the perforation roll.

[0076] The band 13 of the shrink film then continues its path to the insertion conveyor 7. When the tag 26 in question reaches the upper photocells 75 with the film that has been perforated, these photocells generate a signal that causes the conveyor of feed 6 (either through the control unit 25 or vice versa) place a product (P) on the film being moved to the insert conveyor 7. This 5 is done in such a way that there is a label 26 precisely under the product (P), with the film between them, of course. The insert conveyor is used here to create an interval between the products that is appropriate for the packaging machine (for example 50 mm). This interval may be different from the space between the products when they are still in the conveyor 80.

 10

[0077] The insertion conveyor 7 then takes the product to the in-line container sealing unit 8, where the film is tightly sealed on the product, and the packaging is then passed through the retractable tunnel, where the film is contracted in a manner waterproof on the product. The in-line container sealing unit is equipped, for example, with sensors that generate some detector signals, on the basis of which the sealing bars will descend exactly between two products to form a tight seal on them. In the case of the 15 cheese portions mentioned above, the product is tightly sealed along three sides. This ensures that a thick film is created in front, across, at the tip, and along the product, because the relatively large parts of the packaging material are contracted one on top of the other. These thick film parts are often so hard that it is difficult or completely impossible to tear the packing material from them. twenty

[0078] Fig. 5a shows an example of a product packaged by the present method and / or by the packaging machine 1 described herein. The product shown in fig. 5a is a portion of soft cheese that has the conventional shape of a cake portion. A contractile film 91 has been applied on this piece of soft cheese 90. It can also be seen here that the upper part of the film 91 has a perforated opening 94 drawn transversely to the soft cheese portion, and that a label has been applied 93 on the film covering the perforated opening 94. The shape of the tag 93 is shown in more detail in fig. 7. The label has a main part or body 95, which is firmly attached to the film with the help of an adhesive, such as glue. The label 93 also has an area without adhesive or band 96 on its upper part. The band without adhesive 96 (which also includes a band with a neutralized adhesive in the usual way) forms a projection or tongue 97 30 that the user of the product can grab.

[0079] Fig. 5a shows how the perforated opening 94 extends under the tag 93. Dashed lines 100 and 101 show the parts, for example theoretical or actual tear lines, where the user can tear the film. 35

[0080] The user can tear in the film as follows. The small tongue 97 is pulled down. This tongue can be easily grasped, since the strip without glue 96 and the small tongue 97 that are part of it have no glue. When the user pulls the opening piece down (see step S1 in figs. 5a and 5b), the adhesive forces between the label and the shrink film ensure that the upper parts 40 (see fig. 6) of the shrink film which are located just under the perforated opening 94 are also started together with the label 93, so that both come off the product at a given time. If the user continues to pull and finally pulls the film to the ends of the opening 94, approximately along the dashed (theoretical) lines 100 that extend from the ends 102 of the opening 94, it will cause the film to open a lot. more, directly to the edge of the packaging (see opening step S1 in 45 fig. 5b). If then the user continues to pull, the film opens more along the dashed (theoretical) lines 100 '. In this state, the packaging can sometimes be easily removed from the product.

[0081] However, the problem now lies in the fact that the top of the film, that is, the film that is on the widest side of soft cheese 90, has not yet been removed. However, thanks to the special shape 50 of the opening 94, part of the film (i.e., part 105 shown in Fig. 5a) can be used as a tongue. When the user then pulls on this tab 105, the film is detached. Partly due to the presence of the tear tabs 106 extending upwards, the contractile film is torn upwardly, approximately along the dashed (theoretical) lines 101, which start from the corresponding tear tabs 106, of so that the upper part of the film can also be easily removed (this is the opening passage S2 in fig. 5c). This situation is shown in fig. 5c. In the embodiment illustrated here, the elongate opening 94 is provided with other tear tabs or tear openings 108. These tear openings 107 allow the user to tear the film obliquely to the side using tear lines (theoretical) 108, extending from the tear openings 107 (see fig. 5d), in order to be able to partially tear off the remaining corners of the packaging (these are opening steps 60 S3 and S4, shown in fig. 5d ).

[0082] In another embodiment, not shown here, there is (in addition to the band without glue 96 and the adherent part of the label) there is also a part of the label which is given a special layer of glue 110 (see Fig. 7), which makes it possible to close the package again, so that a (partially) open package can be closed again for a while.

[0083] The punch used is different from that shown above as article 70. This alternative punch has two piercing components. The first one has a first height and is used to make an opening only in the film, excluding the label, as described above. However, unlike the case of the punch shown in fig. 6, there are now only two protrusions instead of four, to form the tear tabs 106, so the 5 tear tabs 107 are not found here. On the other hand, the second perforating component has a higher height, so that its use produces both an opening 114 in the film 13, and an opening 120 in the label 93 (see fig. 8). If a product is packaged in a film with a perforated opening and a label applied to it passes to the in-line container sealing unit 8 in this way, the product is tightly sealed and then sent through the retractable tunnel, where air and gases can escape through the ventilation opening 10 made on the label. This is an advantage in the in-line packaging process, since gases can escape through the ventilation opening 120 during the contraction process. When the product has been sealed and packaged as described above, a second label 113 is glued on the first one so that the ventilation opening 114 is sealed in the package and on the first label 93, so that the product can be Hermetically sealed in the packaging and isolated from its environment. fifteen

[0084] The vent opening 120 is preferably U-shaped, but of course other shapes are also possible. Occasionally, it is well known that a ventilation opening can be formed in a contractile film as previously. However, the preceding ventilation openings are often made in a different position, for example in a position opposite to where the label is located. According to the embodiment under discussion, on the other hand, the ventilation opening 120 can be formed on the same side of the product or even where the first label is located. When the ventilation opening is sealed with a second label after the contraction process, this second label can be pasted on the same side of the product or even on the first label.

 25

[0085] Figs. 9a-9h show some examples of embodiments of the opening 94 with a suitable way to remove the packaging material from the product. The opening is always formed to allow the user to tear the packaging in a first direction and then in a second different direction to remove the packaging material at least partially from the product. In some of the embodiments, the second direction is essentially opposite to the first. In some alternative embodiment or other embodiments, the second direction is at a certain angle from the first, being for example essentially perpendicular to it. In the embodiments illustrated here, it is also possible, but perhaps not always necessary to remove the film from the product, subsequently remove the packaging material from the product in one or more other directions, for example to one side. The opening is therefore formed in the packaging signal to open the packaging material in two, three or more directions. 35

[0086] Fig. 9a again shows the opening 94 illustrated in Figs. 5a-5d, with an elongated wavy portion with two tear tabs 106 extending upward, and two other tear tabs 107 extending laterally at a certain angle. Fig. 9a also shows again the upper parts 109 of the film, which are directly under the perforated opening 94. As described above, these 40 parts 109 are pulled together with the tag 93 and thus they come off the product when the user pulls tab 97 down. Fig. 9a also shows the part 105 of the film that can be used as a tongue due to the special shape of the opening 94. As described above, the user can tear the product film upwardly, part 105.

 Four. Five

[0087] The alternative opening shown in Fig. 9b differs from that illustrated in Fig. 9a in that part 105, which can be used as a tongue, now extends beyond the transverse direction of the opening 94. This makes with a longer tongue, which is easier for the user to grip than that formed by part 105 in Fig. 9a, which is relatively short.

 fifty

[0088] Fig. 9c shows a cross-shaped opening 94. This is essentially formed by two tear tabs 104a extending from the center of the opening to the ends 102 obliquely downward, and by two tear tabs 104b extending from the center of the opening at the ends 103 obliquely upwards. Thus a triangular part 109 is formed between the two tear tabs 104a, which is also dragged when the user pulls the tongue 97 downwards, the situation being similar to that occurring in the case of the 55 parts 109 shown in the fig. 9a. The film is then torn from the ends 102 of the tear tabs 104a along the (theoretical) tear lines, which extend obliquely and downwardly from the ends. There is a triangular tab 105, formed between the two tear tabs 104b, with the help of which the user can then tear the product film upward (obliquely), similar to the case described above. The film is then torn from the ends 103 of the tear tabs 104b, along the tear lines (theoretical) that extend from the ends 103 obliquely upward and which can therefore be removed from the product in that address Between the two tear tabs 104a and 104b, there are two triangular tabs pointing to the sides (not numbered), one to the left and one to the right, with the help of which the user can then remove the film from the product laterally . 65

[0089] The alternative opening shown in fig. 9d differs from that shown in fig. 9c in which the opening 94 now has a circular center, from which the tear tabs 104a and 104b extend transversely, similar to the case shown in fig. 9c.

[0090] Fig. 9e shows a star-shaped opening 94, essentially formed by two tear tabs 104a, which extend from the center of the opening to the ends 102 going obliquely downwards, and by a tear tab 104c, which extends from the center from the opening to the end 103 but going upwards. Between the two tear tabs 104a, there is therefore a triangular part 109, which is also removed when the user pulls the tongue 97 downwards, similar to the case of the triangular part 109 shown in fig. 9c. The film will then open tearing from the ends 102 of the tear tabs 104a, along the tear lines (theoretical) that extend from these ends obliquely downward. Two essentially triangular tabs 105a and 105b are formed between the tear tabs 104c and the tear tabs 104a. The user can then separate the film from the product with the help of these triangular tabs 105a and 105b. When the tongue 105a is pulled obliquely and upwardly to the left, the film tears more along a tear line that extends from the tear tab 104c. The film then comes off the product and can be removed from it in the direction of the upper left corner. By pulling the tongue 105b obliquely upward to the right, the user can also tear the product film in the direction of the upper left corner of the product.

[0091] The opening shown in fig. 9f differs from that illustrated in fig. 9d in which the opening 94 now has a U-shaped part, from which the tear tabs 104a and 104b extend similarly to the case shown in fig. 9d The base of the U-shaped opening points points upward, so that part 109 is formed by the elongated internal part of the U. In an alternative embodiment not shown here, the base of the part-shaped part of points U points down, and the elongated inner part forms the tongue 105. Fig. 9g shows another alternative type of opening 94, with an elongated wavy portion with two ends 102 and two tear tongues 25 106, which extend upward. As in the case shown in fig. 9a, the elongated part has two upper sections of film 109, immediately under the perforated opening 94. As described above, sections 109 are torn off together with the tag 93, thus detached from the product when the user pulls the tongue 97 down. Similar to the case shown in fig. 9a, the opening 94 can be used as a tongue, due to its special shape, this tongue being shown here as article 105. When the user pulls the tongue 97 down, the film opens from the ends 102 of the opening a along the (theoretical) tear lines that extend obliquely downward from the ends 102. The user can then remove the film of the product in an upward direction with the aid of the tongue 105, similar to the case shown in the fig. 9a. Between the tear tabs pointing obliquely and upwardly 106 and the obliquely downward signaling portions of the opening (extending 35 to ends 102), there are two triangular tabs pointing obliquely (unnumbered), one on the left and one on the right, with the help of which the user can then remove the film from the packaging in an upward direction.

[0092] Fig. 9h shows another alternative type of opening 94, which has an elongated part, with a straight middle part 40, from which two sections extend obliquely downwards, to the two ends 102. These are also equipped with two tear tabs 106, that extend upward. With the aid of the opening 94, the user can remove the film in a manner similar to that used in the case of the opening shown in fig. 9g

 Four. Five

[0093] As an alternative to the mechanical punch described above, which can make an opening in the film and / or on the label with the aid of a punch, a piercing component 70 or a similar piece, other means can also be used to make a opening. An example is a laser cutting unit, where a focused laser beam is used to make an opening in the film and possibly also in the label. The advantage of such a laser system is that it is very precise and works without having contact with the substrate, which reduces the deterioration that it entails. The problem of such a laser solution is of course that it is generally more expensive.

[0094] The product can be passed through the packaging machine first to pack it in a packaging material of one type, after which it is passed through the same packaging machine or through a different packaging machine a second time to be packaged in a packing material of a second type. 55

[0095] In the embodiments described above, the packaging device has a lower roll configuration (also called underfeeding configuration), but other configurations, such as an upper roll configuration (also called overfeeding configuration) are also known. by the expert in the field. Other examples of configurations include those in which a packaging material with a covering element is used in a vertical or horizontal line packaging machine, a top sealing machine, a deep drawing machine, a skin type machine, a edge sealer or similar sealing machine.

[0096] The device and method described herein can be used to provide a product with a primary packaging, 65 but can also be used to provide a product or products with a secondary and / or tertiary packaging. He

Packaging material can be used for example to pack a product or a set of products that have already been packaged one or more times.

[0097] Although packaging machines for packaged food products are frequently mentioned in the above embodiments, the invention is not limited for use with food products. The method and device can in fact also be used for example in many other fields outside the food sector, for example to pack one or more optical or electronic data carriers (CDs and DVDs), to seal cardboard boxes to easily open these boxes (using the openings made in the packaging to remove the packaging material), and in the packaging of medicinal products. In the latter case, the method according to the present invention can for example provide a way of sealing the packages with a secure closure. The skin type machines 10 are currently available in different forms, ranging from the traditional ones, which gradually eliminate a roll, to the more modern variants, such as those that work with preformed trays in upper sealers provided with a skin type material, as well as modern deep stuffers, with a subsequent heat treatment that subsequently makes it possible for the film to fit around the product by the use of water or by a dip bath. The materials used to apply a skin type container 15 are called packaging materials used in skin type machines, or simply skin films.

[0098] It has been mentioned above that contractile films are difficult to remove from the product without damaging the latter. This also applies to products packaged in an extensible film or a skin film. The present invention also helps solve this problem and simplify the opening of such packages. The use of the method and device according to the invention also reduces the risk of a leak from the space between the packaging material and its cover element. Thanks to the double opening direction, the products can be removed from the packaging more easily. According to the invention, the user can freely choose between the different points to start opening the packaging (on the label), and this feature can be used to optimize the system for each type of product during the packaging operation, thus making the packages are easier to open. 25

[0099] The present invention is not limited to the preferred embodiments described above with respect to devices, methods, products and types of film. The rights requested here are better defined in the following claims, and it is possible to make numerous variations and modifications within your possibilities. 30

Claims (18)

1. Drilling unit, comprising: - a rotary reinforcement roll (34), 5 - a rotary drilling roll (33), and - a frame (30) in which the reinforcement roll (34) and the perforation roll (33) are arranged relative to each other, the perforation roll (33) being arranged to rotate independently of the reinforcement roll (34), 10 characterized by the fact that The drilling unit is arranged in one of the following provisions: - the perforation roll (33) is equipped with a first guide (57) and a second guide (58), the first and second guides (57, 58) being arranged at opposite side ends of the drilling roll (33) and fifteen - the perforation roll (33) is arranged in the frame (30) to cause the first and second guides (57, 58) of the perforation roll (33) to rotate against the reinforcement roll (34), so that the first and second guides (57, 58) of the perforation roll (33), which are mounted on bearings (43, 44), can rotate with respect to the perforation roll (33)  twenty or - the reinforcement roll (34) is equipped with a third guide and a fourth guide, the third and fourth guides being arranged at opposite side ends of the reinforcement roll (34), and - the reinforcement roll (34) and the perforation roll (33) are arranged in the frame (30) to make the third 25 and fourth guides of the reinforcement roll (34) rotate against the perforation roll (33), so that the third and fourth guides, which are mounted on bearings, can rotate with respect to the reinforcement roll (34) or 30 - the perforation roll (33) is equipped with said first and second guides and the reinforcing roll (34) is equipped with said third and fourth guides, respectively, and - the reinforcement roll (34) and the perforation roll (33) are arranged in the frame (30) to make the first and second guides of the perforation roll (33) rotate against the third and fourth guides of the reinforcement roll (34), 35 so that the first and second guides of the perforation roll (33) and the third and fourth guides of the reinforcement roll (34), respectively, which are all mounted on bearings, can rotate in relation to the perforation roll (33) and to the reinforcing roll (34), respectively. 2. Drilling unit according to claim 1, wherein, in case the perforation roll (33) is equipped with said first and second guides (57, 58), the drilling unit has a fifth guide (29) and a sixth guide (29) having rolling surfaces, wherein said fifth and sixth guides (29) are fixed in an adjustment bridge (45) so that the rolling surfaces of said fifth and sixth guides (29) can push against the first and second guides (57, 58), respectively.  Four. Five 3. Drilling unit according to claim 2, wherein said adjustment bridge (45) has two adjustment knobs (46, 46 '). 4. Drilling unit according to any of the preceding claims, further comprising: - at least one punch (70) that is mounted on the drilling roll (33) to open, from an initial position, an opening in a packing material (13) that is introduced at a feed rate and is equipped with a coverage element (26). 5. Drilling unit according to claim 4, further comprising:  55 - a control unit and (coupled to it) a sensor (85) to emit a signal when it detects a covering element (26), the drilling operation being performed by the punch (54) that controls this signal. 6. Drilling unit according to claim 4 or 5, wherein at least one punch (70) comprises a piercing component extending from said drilling roll (33) to a height (h) so that, in use, said Punch is arranged to open said opening in said packing material (13) or not to do it or not to do so substantially in said covering element (26). 7. Drilling unit according to any of claims 1-6, comprising:  65 - a first drive motor (50) driving the reinforcing roll (34), - a speed detector (17) that determines the speed at which the packing material (13) is introduced and emits a speed signal representing its feeding speed, and - a control unit coupled to the first drive motor (30) and the speed detector (17), to regulate the speed of rotation of the booster roll (34) according to the speed signal, where the control unit is used to emit a control signal that causes the speed and / or acceleration of displacement of the reinforcement roll (34) to be substantially the same as the speed and / or acceleration at which the material of Packing (13) is introduced. 8. Drilling unit according to claim 7, wherein the speed detector comprises a coding roll (17), along which the packing material (13) passes and which includes a tachometer and an encoder, used to determine the Momentary feed rate and to emit a speed signal representing the momentary feed speed of the packing material. 9. Drilling unit according to claim 7 or 8, wherein the reinforcing roll is hollow at least partially and preferably substantially. fifteen 10. Drilling unit according to any of claims 1-9, wherein the perforation roll (33) has both a central part (42) and a perforating component (70), which is installed so that it can move laterally to the part center (42), where the piercing component can be fixed in any desired lateral position with respect to the reinforcement roll. twenty 11. Drilling unit according to any of claims 1-10, comprising a second electric drive motor (62) for driving the drilling roll (33), and a control unit coupled to this second drive motor (62) which it is used to control it and to rotate the perforation roll (33) from a standby position at the same speed as that of the reinforcement roll (34) during the perforation of an opening, 25 and then to carry the perforation roll (33 ) to a next waiting position at a higher speed, after having drilled an opening. 12. Drilling unit according to claim 11, wherein the control unit that is coupled to the second drive motor (62) is used to emit a control signal to the second drive motor (62), with the aid of which the speed and acceleration of the displacement of the perforation roll (33) during the drilling operation are essentially the same as the speed and acceleration at which the packaging material (13) is introduced. 13. Drilling unit according to claims 6, wherein the punch of the drilling unit has another perforating component for opening another opening both in the packaging material and in the covering element below it. 14. Drilling unit according to claim 13, comprising a unit for applying the cover element that has been used, after another opening has been made in the cover element, especially a label, to apply another cover element for seal said other opening. 15. Device for packaging a product, comprising: - a drive unit for inserting into a packaging material selected from a set of packaging materials 45 including a shrink film, an extensible film, a combined shrinkable and extensible film and a skin film, - a drilling unit according to any of claims 1-14, and - a packaging unit to pack the product in the packaging material.  fifty 16. Device according to claim 15, wherein the drive unit, the application unit of the cover element, the punch unit and the packaging unit are integrated into each other so that it is possible to use an in-line packaging process. 17. Device according to claim 15, wherein the packaging unit is separated from the drive unit, the application unit of the cover element and the punch unit, so that it is possible to carry out an off-line packaging process. 18. Method of in-line packaging of a product with a device according to claim 15, 16 or 17 comprising: 60 - the introduction of a packaging material, - the application of at least one cover element to the packaging material, - the formation of at least one opening in the packing material at the place of the covering element with said perforating unit, essentially without forming the corresponding opening in the covering element 65 beyond it, and - the packaging of at least one product in said packaging material, which comprises placing at least one product in the packaging material and sealing the packaging material either in an online process or in an offline process.