FIELD OF THE INVENTION

The present invention concerns a manufacturing method for realizing afoldable bag for a containing box for packaging ofproducts, especially food products, and particularly fresh, frozen, semi-processed and processed alimentary food products, and the like, and flowers.

More in details, the manufacturing method according to the present invention is directed to obtain the foldable bag of the containing box of the type described in the patent application n. PCT/EP2011/061751 in the name of the same applicant. PRIOR ART

Are known in the art containers for the storage, and/or display, and/or shipping of food products, such as vegetables, fruits, meat, fish, seafood, agricultural products, including flowers, and similar.

The conventional containers already known on the market belong substantially to three main categories: containers made of cardboard, containers made of corrugated boards mainly of polypropylene or PVC, and containers made of injected plastic, whether foldable or solid.

Each of the known solutions is affected by several drawbacks.

In fact, for example, the containers made of cardboard can adsorb humidity and transfer such humidity to the products. The cardboard can also adsorb tastes and smells from the products and, therefore, it is not possible to reuse the same container several times.

Moreover the cardboard for food:

a) has to be treated with fungicide;

b) it is not stackable but only superimposable;

c) the content it is not visible;

d) reduce the speed of cooling of the content;

e) reduce the aeration of the content;

f) in case of contact with water or with a serious humidity has deformation problems. The commonly used containers made of PVC or polypropylene or plastic in general have not all the inconvenient of the cardboard one but, in comparison with the present invention, are more heavy, and therefore are more expensive both with reference to the manufacturingg process (cost of raw material and energy) productand transport.

Moreover the conventional non foldablecontainers made of plastic materials take a lotof space during the storage and the transportation with a consequent increase of the cost of energy and space.

In order to overcome such drawbacks, the priority application describes a containing boxfor the storage and/or shipping of products, in particular for food products such as meat, agricultural products like fruits and/or vegetables including flowers, which is very lightweight, durable, stackable, washable, odourless, airy, with a perfect visibility of the content and able to provide a great level of protection during transportation and/or storage of the contained products.

SUMMARY OF THE INVENTION

The containing box developed by the same applicant and claimed by the international application n. PCT/EP2011/061751 has been conceived as the perfectly hygienic, ecological and economic substitute for the present packaging systems based on corrugated carton boxes and trays as well as traditional plastic crates.

This means to be able in the future to manufacture the innovative packaging products on a very large scale all over the world.

Such mass production similar to that of the classical carton boxes or trays will only be possible by an adequate manufacturing method passing directly from the present individual bag production to an endless and widespread manufacturing system based on the best possible production capacity.

The present invention therefore concerns a continuous bag production method.

These aims and these objects, and others that will be more clear after the detailed description of a preferred embodiment of the present invention, are achieved by amanufacturing method of the foldable bag of a containing box for the storage and/or shipping of products, according to the scope of protection of the attached claims. More in detail, the present invention concerns a manufacturing method for preparing the foldable bag of a containing box comprising a foldable bag, of the type disclosed in the international application PCT/EP2011/061751.

The manufacturing method according to the present invention wants to reach and assure the aims of making packaging and logistics smarter, easier and more efficient by its cleaner, greener and cheaper approach. In this way it will finally help to drastically cut down the worldwide deforestation and spilling of the nature by dangerous chemicals used by the paper industry on one hand and on the other by reducing the need of virgin plastic material employing essentially already recycled plastic material to manufacture the containing box.

The above mentioned objects can be achieved by an endless bag production method according to the present invention.

More in details, the manufacturing method according to the present invention is based essentially on extrusion or weaving manufacturing of a seamless plastic film or net tube with three or four different structural tube parts or rings necessary to realize reliable and high quality bags for the containing box system.

Such tube should possibly be made of weldable plastic material or in the case of most of the plastic net realized by the insertion of weldable material (film strip or other). The following production proposal consists in several different steps, preferably five steps, hereafter explained to be carried out by a single production line.

BRIEF DESCRIPTION OF THE FIGURES

Further characteristics and advantages of this invention will become clear from the following detailed description of a preferred embodiment that is merely illustrative and not limitative and is shown in the figures that are attached hereto, in which:

- figurel shows a prospective view of the container according to the present invention in an assembled condition;

- figure 2 shows a prospective view of a detail of the frame of the container according to the present invention in a partially disassembled configuration; - figure 3 shows other parts of the frame of the container (legs) according to the present invention in a disassembled configuration; - figure 4 shows a front view of a detail of the frame of figure 2 partially assembled with the parts of figure 3;

- figure 5 shows a side view of the detail of figure 4;

- figure 6 shows two containers according to the present invention one stacked on the other;

- figures from 7 to 12 disclose one possible manufacturing process of a part of the container according to the present invention;

- figure 13 discloses a schematic top view of the tubular film or net structure corresponding to one bag, according to the manufacturing method of the present invention;

- figure 14 discloses a schematic half cross section of the foldable bag obtained with the manufacturing method according to the present invention;

- figure 15A discloses again the schematic top view of figure 13;

- figure 15B discloses a schematic perspective view of a cylindrical support structure used during the manufacturing method of the present invention to support the tubular structure during the initial steps of the folding process;

- figures from 16A to 16D disclose some steps of the method according to the present invention, by which the cylindrical cross-section of the film or net tube is folded and flattened by means of ironing;

- figure 17 discloses the punching operation;

- figure 18 a schematic representation of the apparatus for performing the manufacturing method according to the present invention;

- figure 19 discloses the sealing of the bag bottom and the realization of the tear off pre-cut;

- figure 20 discloses the realization of the reinforced bag carrier ring by means of the insertion of a plastic film strip fixed by thermic sealing;

- figure 21 discloses the realization of the final seals on the bag.

DESCRIPTION OF THE INVENTION

According to the international application PCT/EP2011/061751 in the name of the same Applicant, acontaining box 100has been developed which comprises a rigid frame, indicated with the reference number 10, and a bag indicated with 20.

More in details, with reference to figures 1 to 5 the containing box 100 comprises an assemblage rigid frame structure 10 which comprises a main structure 11 with a closed profile to which a plurality of leg elements 12 are removably connected. More in details, the main structure 11 is in the shape of a closed planar structure, preferably a quadrangular structure such as a square or rectangular structure, and the leg elements 12 are in number of four, one for each corner of said structure 11. With particular reference to figures 4 and 5, the main structure 11 comprises two parallel long sides 11a, 11b and two parallel short sides 11c, 11d, thus forming a rectangular structure.

The rigid frame structure 10 of the containing box 100 is therefore constituted by a rigid main structure 11 and by a plurality of foot elements 12 to be assembled to the said main structure 11 before the use.

In the embodiment disclosed by the attached figures theframe structure 10is made of a rigid frame11 and four Iegs12, where said four legs and the frame are produced by two separate injection operations. The height of the legs depends on the needs and use and are automatically inserted into the frame by a simple machine at the end-users facilities (packaging houses etc.) together with the foldable bag 20.

Once the feet are inserted into the frame they create at the top of the frame itself four corner pins in the upper part, indicated with the reference numbers 12'. Thanks to this feature, stacking the loaded containing boxes at the moment of palletizing, these pins12' enter into the bottom aperture of the legs 12 of the upper box thus enabling the safe stacking of up to 240 cm in height to ensure stability even under poor transport conditions. The situation is shown in figure 6.

With reference to figure 1 , the containing box further comprises a foldable bag 20. The foldable bag 20 is made of a single sheet of plastic mesh or film of similar recyclable materials, the sheet being folded according to the manufacturing method here disclosed and claimed.

The bag 20 resulting from the manufacturing process according to the present invention is closed in the four corners of the polygonal structure 11 of the frame 10, and it wraps completely said polygonal structure 11 thus ensuring in this way the perfect lodging of the contained goods no matter if they are loaded manually or by automated loading machinery. The foldable bag 20 is therefore a non-rigid and suspended component.

Thanks to the fact, in particular, that the bag is suspended on the rigid frame 10, any kind of loaded products can be securely contained in the container and protected against bumps and blows.

The bag is manufactured according to the various models of the frame 10.

The bag is closed in the four corners of the frame, and it wraps it completely ensuring in this way the perfect lodging of the contained goods no matter if they are loaded manually or by automated loading machinery. The bag, the non-rigid and suspended component of the containing box, contains securely any kind of loaded products protecting it perfectly against bumps and blows.

The present invention therefore concerns the manufacturing method for realizing the bag 20starting from a tubular structure made of plastic mesh or film.

According to PCT/EP2011/061751 a first manufacturing method for realizing the bag 20 is shown in figures 7 to 12. In particular, figure 7 shown the sheet, the dashed lines indicating the folding lines. By means of inwardly folding the corners of the sheet as shown in figure 8, the foldable bag 20 is formed. As shown in figure

9, sealing elements 22, such as sealing films, can be provided in order to close the folded ends of the bag 20.

Additionally, further sealing plastic films 23a, 23b, 23c, 23d can be provided on the upper edge of the four sides of the bag 20, as shown in figure 10, thus forming a substantially foldable structure 24 adapted to be connected to said frame 10. More in detail, the foldable structure 24 has a substantially box-like shape, protruding toward the outside with respect to the upper edges of the bag 20 so that it can be positioned on said man structure 11 of the frame 10.

As shown in figure 12, the box-like shaped foldable structure 24 is advantageously provided with fixing corner holes 25, one hole at each corner.

Each one of said holes is adapted to receive the upper end of one corner of said polygonal main structure 11 , thus fixing in a stable and suspended position the foldable bag 20 with respect to the frame 10.

In alternative embodiment, the foldable bag 20 is directly connected to the frame

10, without the necessity of providing the upper edge of the bag with the foldable structure 24. In order to achieve the necessary mechanical strength of the upper edge of the bag, the same is folded in a specific way in order to have a double layer of sheet in the upper edge region of the bag.

The foldable bag 20 is preferably made of plastic, a material that does not absorb or transmit liquid, humidity, odours or germs of any kind. It is a one-way packaging system, but it may also be employed as a multi-use packaging depending on the needs of the client.

According to the present invention, a manufacturing method which allows mass production of the foldable bag 20facilitating its packaging and the final assembling with the containing box frame will now be described.

Some definitions are provided here below in order to render much more clear the description which will follow.

Tear off ring: is the zone where the single bags can be separated by pulling it off at the moment of mounting mechanically the containing box by automated machinery or manually. The tear off ring can be realized either by pre-perforation or pre-cut of the film or net structure just at the limit of the previous ring. This allows on one hand the endless continuation of the bag band and on the other one the easy separation or tearing off of each single bag at the moment of mounting the containment box. The width of this ring is just a perforated or pre-cut line.

Reinforced or strengthened ring: is a zone of the tube structure obtained by double folding of the endless tube. In one of the embodiment here described as example, the double folding is obtained by a first folding, backward, a stretch of said tubular structure, preferably having a length of 200 mm, and then folding, forward, a stretch of said tubular structure having a length which is the half of the previous length, referable having a length of 100 mm, thus creating a triple layer belt of 100 mm.

As an alternative to the step consisting of folding the tubular plastic structure first backwards by a 200 mm and then forwards by a 100 mm in order to create the above mentioned reinforced or strengthened ringof the bag, it is possible to realize it by a lateral insertion of an up to 100 mm wide transparent plastic film strip to be securely sealed to the tubular structure, especially at the points where the four angular carrier holes will be realized during a subsequent production step. Applying this alternative method the thickness of such plastic strip can be chosen in function of the type and specific weight of the product to be contained guaranteeing in this way the absolute conformity of carrier strength regarding the product to be loaded under all kinds of storage and/or transport conditions. This possibility is illustrated in Figure 20.

The reinforced or strengthened ring either realized by backwards and forwards folding of the tubular structure or by the lateral insertion of a plastic film to be fixed by heat sealingwill at the moment of mounting the box embrace the outside of the frame or rigid containment box structure, the upper part of the frame as well as partially the inside of it, the situation is disclosed in figure 14, and its four angle pins which will enter the four carrier angle holes to be created in a step of the manufacturing method. The so obtained three layers of film or net have then to be welded or sealed completely or partially in order to create the carrier ring. In the case of a tubular structure made of net, the three layers obtained by the double folding have to be completed by the insertion or injection of an additional material, e.g. filmstrip or other, and then welded or sealed together to get a permanent carrier ring.

The width of this bag ring supporting the weight of the product to be loaded in containing box should preferably be of 100 mm.

This reinforced ring is not necessary when some materials are used for tubular structure. For example, when plastic materials such as Pluriball or Bubblewrap are used, there is no need to create such reinforced-triple layered-zone.

Film or net tubular structure: a tubular structure made of plastic film or net,or made of a layer of pluriball or bubblewrapis the semi-finished product from which the manufacturing method according to the present invention starts, in order to create the foldable bag.

Preferably, the length of this tubular structure has to be 250 mm, 120 mm for the bag side walls and 130 mm for the bag bottom, as will be more clear by the following description of the method steps.

The total volume capacity of the bag is preferably at least 15 litres once mounted to be loaded.

Termination or closing ring: in the case of film tube structurally like ring 3 to be sealed once the lateral infolds and the flattening of the film tube, which will be described in the following detailed description of the manufacturing method according to the present invention, have been applied. This seal will become the middle line of the bag.

In case of tubular structure made of film, an injection or insertion of an additional material, e.g. film strip, is necessary to guarantee the correct sealing of the bag bottom in a further step. Preferably, the width of this ring is approximately of 10 mm.

The endless production of the foldable bag 20 by one single production line according to the method of the present invention starts from a polypropylene or polyethylene film or net tubular structure300 that will be rolled up on a cylinder at the end of the production line.

This tubular structure300is therefore provided in rolls as semi-finished product.

Such bag roll is wrapped in transparent plastic film in order to avoid the contamination with dangerous substances or elements.

This procedure allows to avoid complicated packaging necessary for individual finished bag manufacturing processes and the semi-finished product consisting of the bag roll of tubular structure300 can be easily mounted on the manufacturing apparatus suitable to perform the method of the present invention.

The manufacturing of the bag according to the method of the present invention is realized by passing through several steps performing mechanical operations in an aligned and simple work stations sequence.

By the manufacturing method according to the present invention, each bag results to have a perfectly standardized shape.

The steps of the manufacturing method of the present invention will now be described.

First of all, a rolled up seamless tubular structure300 made of film or net with a predetermined perimeter forming a bag roll as previously described, preferably having a width of 1.400 mm, is opened and passed over a cylindrical support structure 800with a corresponding diameter. Here a double folding is carried out by means of first folding means 700creating the bag carrier belt or reinforced ring400, including the sealing of said ring.

This step is shown in figure 15A, which is a top view of the unrolled tubular structure300, and in figure15B, which represents a scheme of the tubular structure 300 positioned on said cylindrical support structure 800, wherein the carrier belt or reinforced ring400 has been created by means of two folding operations by means of first folding means 700: the free end of the tubular structure is folded two times. In the preferred embodiment here described as an example, the double folding is obtained by a first folding, backward, of a stretch of said tubular structure, preferably having a length of 200 mm, and then by a second folding, forward, of a stretch of said tubular structure having a length which is the half of the previous length, referable having a length of 100 mm, thus creating a triple layer belt of 100 mm.

In the case of net tube, the injection or insertion of an additional material, such as a film strip or other similar materials, are further provided before the sealing.

In the case of pluriball or bubblewrap material, these steps are not performed because it is not necessary to create the carrier belt or reinforced ring 400.

With reference to figure 16A, the tubular film or net300then slips off the cylindrical support structure800and enters second folding means500comprising four longitudinal elements provided at the vertex of a quadrangle so that the cross- section of the tubular structure 300 assumes a quadrangular shape, as shown in figure 16B.

Therefore, the second folding means 500are suitable to deform the cylindrical tubular structure 300 in a tubular structurehaving a rectangular cross-section, and then are suitable to apply on both the lateral sides of the rectangular tubular structure a symmetrical infold lateral force indicated withF in figure 16B, preferably realizing a 150 mm symmetrical infold, until the tube is completely flattened to a film or net tubular band as shown in figure 16C, having preferably a width of 400 mm.

This flattening operation is completed by passing the tubular band inside flattening means 600, e.g. between two parallel metallic cylinders, the upper one lying freely on the fixed lower one exercising in this way by its weight an "ironing" pressure on the passing though tubular film or net band. The step is illustrated in Figure 16D. By heating the upper roll, the ironing effect could be increased.

The flattened film or net tubular band300, which still maintains a closed cross sectional perimeter, then passes through a punching unit 900 where four main corner carrier holes are provided by punching mechanically, by means of punching means 950, a half-moon 960 with a diameter of 25 mm on the external lateral edge of the flattened film or net band, as shown by Figure 3.

Alternatively, instead of the mechanical punching operation described, the external lateral edges of the flattened film or net band can be locally burnt in order to pierce the plastic material. It has been found that local burning is preferred in case of pluriball or bubblewrap.

In any case, the central point of the half-moon hole has to be placed on both edges of the external lateral edges, preferably at a distance of 72 mm from the upper horizontal edge of the flattened tubular band.

By similar punching of a further hole, preferably having a diameter of 5 mm, at the centre of the carrier band, in the example this further central hole has its central point at 72 mm from the upper horizontal hedge of the carrier ring, secondary carrier holes for additional bag holding pins in the middle of the top of the long side frame bares are created.

With reference now to figure 18, from the punching unit 900 the tubular film or net 300passes through a sealing unit lOOOwhere the bottom of the bag is sealed by sealing means 1050,in the example by a 3 mm seal. In the case that the tubular band has a net structure, an additional injection or insertion of another material, e.g. a film strip or other materials, is made before in order to obtain a resistant sealing of the bag bottom.

The sealing means 1050 realize a transversal sealing line on the continuous tubular band.

After the sealing of the bag bottom, the so obtained endless band is guided through a pre-cut unit 1100 where a pre-cut or perforation of the bag band is performed by pre-cut means 1150 along the upper edge of the carrier ring of the bag allowing an easy manual or mechanical tearing off of each bag from the bag roll.

The pre-cut is realized close to said sealing line andupstream to said sealing with respect to the forwarding direction of the tubular structure 300, the forwarding direction of the tubular structure being indicated, for example, by the arrow of figure 18.

In case of plastic film or bubblewrap, the manufacturing method can additionally comprise a further step consisting of perforating the flattened tubular band 300 by means ofperforation means 1200 which can create a plurality of holes on the lateral faces of the bag in order to let air to circulate inside the bag once it is assembled on the frame 11 and in use.

The endless bag manufacturing process is then completed by the automatic rolling up of the bag band on a cylinder, the wrapping of it in plastic film and the final labelling for shipping it to its final destination.

One bag roll will contains several foldable bags, e.g. at least 1.000 bags.

The situation is disclosed in figure 19.

The above presented endless or continuous bag manufacturing method will allow mass production of the bag 20 of the containing box 100.

Depending on the type product to be packed, the foldable bag 20 can be realized starting from a single sheet of different materials or different structures: made of net or mesh, micro-perforated plastic film, classic plastic film or transparent plastic, and similar structures, whatever provides the most ideal conditions for the transport or storage of products.

Several advantages are achieved by the

The concept ensures maximum ventilation and excellent protection of the products contained and allows the application of all kind of cooling and freezing in a very reduced time.

Additionally, it has been found that the containing box according to present invention is resistant to high and low temperatures in the range of +45°C to -25°C. The container can also be washed with its content without any difficulty (from the field to the end-user). This was not possible, for example, with the containers made of cardboard known in the art.

The content of each containing box is perfectly visible and can so easily be controlled. Using containing boxes made of net or transparent film the visual impact is particularly striking and any type of containing box can be personalized according to customer's marketing needs etc, by placing logos, images or marks, for example, on the external surfaces of said box-like shaped foldablestructure. It has therefore been shown that the manufacturing method for realizing a foldable bag of a containing boxaccording to the present invention achieves the purpose and the objects proposed.

In fact, the manufacturing method according to the present invention reaches the aims of making packaging and logistics smarter, easier and more efficient by its cleaner, greener and cheaper approach.

In order to assure a cubic conformation of the bag or flexible structure of the container for the packaging system according to the present invention, especially designed automatized assembling machine applies after mounting the bag on the rigid structure an additional lateral sealing in the middle of the short sides at the bottom of the now open and perfectly positioned bag. These sealing points assure the classic box conformation of the finished container ready to receive its load allowing the perfect use of the available volume space and avoiding any unwanted infiltration of the to be loaded product in the bottom folds of the flexible structure of the container, a factwhich could reduce its content volume by deformation of the wanted and necessary conformation. The situation is disclosed in figure 21.

The production line of the bag or flexible structure will be integrated completely in the automatized assembling machine combining in this way all components of the absolutely innovative packaging system described in the patent application n. PTC/EP2011/061751 , i.e. frame, feet, bag and the personalized marketing strip. Said automatized assembling machine will be installed directly at the packaging plants providing at high speed the completed containers or boxes over a conveyor belt to the various product loading stations.

It will be apparent to the person skilled in the art that various modifications can be conceived and reduced to practice without departing from the scope of the invention.

Therefore, the scope of the claims is not limited to the illustrations or the preferred embodiments shown in the description as an example, but rather the claims include all the patentable novelties deriving from this invention, including all the equivalent embodiments for a person skilled in the art.