ITRE20110006A1 - PLANT AND PACKAGING METHOD FOR FOOD PRODUCTS - Google Patents

Description

DESCRIPTION

â € œIMPLANT AND PACKAGING METHOD FOR PRODUCTS

FOODâ €

The present invention relates to the packaging of products, mainly of loose products, for example of the food type such as biscuits, candies, cereals, dried fruit and the like.

More specifically, the present invention relates to the packaging in bags of a metered quantity of loose products by means of so-called `` flyers '' sealed bags which have a lower rectangular base (possibly square) having a flat horizontal surface obtained by means of a complex folding on a tubular wrapper. with closed section (here called â € œcomplex foldingâ €), and a flat welded top obtained by simple crushing of the tubular casing so that there are no parts folded towards the inside of the tubular itself (here called â € œsimple foldingâ € ), forming an upper extremity defined by two straight edges welded together.

The creation of flyer packages is notoriously complicated in the industrial field.

In fact, automated systems are known for the packaging of products which produce bags having both the bottom and the top folded in the same way; a first known type of package therefore has both ends of the envelope with complex folding, while a second known type of package has both ends of the envelope with simple folding, as described above.

The systems of the known type used for the production of such packages provide for a strip of flexible film to be unwound from a reel and passed through a forming device comprising a vertical forming tube to which a shaped collar is associated.

By sliding in contact on said collar, the flexible film strip is forced to orient itself vertically and fold back on itself so as to take the form of a sleeve that wraps the forming tube.

The sliding of the flexible film belt is obtained by a pair of motorized tracks located downstream of the collar, which adhere to the flexible film by friction or by means of a suction system.

The packaging plant also comprises first sealing means which are adapted to join together the free vertical edges of the flexible film strip, so as to close the sleeve laterally.

The system then comprises second sealing means (in the case of simple folding envelopes) or folding-sealing means (in the case of complex folding envelopes), which are suitable for transversely sealing the film strip. flexible under the forming tube, so as to close the bottom of the sleeve in a flat rectangular way.

Figure 1 shows a succession of phases a) - e), for the realization of a rectangular flat bottom starting from a tubular of flexible tape, indicated with the letter A, downstream of a forming tube.

To fold two opposite edges of the bag towards the inside of the same, two shaped bars C are used, for example with converging profiles, which, moving towards each other, fold the flexible tape cylinder as shown in the sequence of steps c) and d ).

Downstream of these shaped bars C there are two sealing bars B, which are opposed, horizontally oriented and horizontally movable in reciprocal approach along a direction orthogonal to the direction of approach of the shaped bars C, to clamp the flexible film sleeve in a vice and at the same time heat-seal the flexible film thus forming a closed and flat bottom for the support of the products.

The products to be packaged are dosed with suitable weighing means and subsequently released inside the forming tube, so that they collect by gravity in the bottom of the closed sleeve at the lower end of the tube.

Subsequently, after having made the flexible film sleeve advance vertically, the second sealing or folding-sealing means start again to seal the flexible film strip transversely above the collected products, hermetically sealing the section of sleeve in which they are contained and at the same time creating a new closed fund homologous to the previous one ready for a new cycle.

The envelope thus obtained - as shown in figures 10 a) and b) -, filled and sealed at the ends, is finally separated from the flexible film tape by means of suitable cutting means, and the cycle is repeated.

The impossibility of making flyer envelopes starting from the same tube of flexible film is evident, as the need to fold and seal the bottom, shaping it according to a planar quadrangular profile, appears incompatible with creating a profile in the upper part of the envelope flat, without flaps of flexible film being folded inside the package.

In fact, the portion of flexible film which is folded due to the conformation of the planar bottom inevitably results in a homologous folding also in the top of the envelope.

Therefore, for the realization of flyer envelopes - visible in figure 10 c) - dead times of plant shutdown are required due to the cutting and opening phases of the flexible film flaps folded inside the package, for removal of the same, as well as for the welding of the top with a simple bending profile. The object of the present invention is to solve the aforementioned drawbacks of the known art, by making available a method and a packaging device which allow to produce so-called flyer packages, without decreasing productivity or at least without excessively reducing it.

A further purpose of the invention is to achieve the aforementioned objective in the context of a simple, rational and low-cost solution.

These objects are achieved by the characteristics of the invention reported in the independent claims. The dependent claims outline preferred and / or particularly advantageous aspects of the invention.

In particular, a plant for packaging products in bags is made available which includes

- a forming tube with a substantially vertical longitudinal axis whose upper end is adapted to receive the products to be packaged;

- winding means for wrapping a flexible film tape around the forming tube;

- first conveyor means for making the flexible film strip slide along said forming tube in the direction of the longitudinal axis of the forming tube itself;

- folding, sealing and cutting means for folding, sealing and cutting the flexible film strip so as to form at the lower end of the forming tube a bag with a flat bottom comprising a portion of the plane substantially orthogonal to the longitudinal axis of the forming tube;

characterized by the fact that

- the cutting means for cutting the flexible film strip are arranged downstream of the folding and sealing means, in the direction of advancement of the first conveyor means, for the realization of an open end of the bag above said flat bottom and by the fact of comprehend

- a support surface intended to support the open bag resting on its bottom placed under said cutting means,

- second conveyor means independent from the first conveyor means and able to move the bag, filled with products to be packaged and resting on the support surface, relative to the forming tube with a direction transversal with respect to its longitudinal axis.

Thanks to this solution, it is possible to reduce, if not eliminate, the downtime in the production of flyer packs.

According to a preferred aspect, the invention makes available a method for the packaging of products which comprises the steps of

- forming a bag with a closed end by means of a substantially flat bottom substantially orthogonal to the longitudinal axis of the bag and an open end arranged above the bottom and

- fill the formed bag with products,

characterized by understanding the phases of

- move the formed bag sideways,

- flatten the open end of the bag, by simply overlapping two upper flaps of the same, with respect to a plane parallel to the longitudinal axis of the bag and

- close the flattened open end.

Further characteristics and advantages of the invention will become evident by reading the following description provided by way of non-limiting example, with the aid of the figures illustrated in the attached tables. Figure 1 a) is an axonometric view of a first step of folding a bag, by means of known folding-sealing means, for the production of a flat bottom (in the rectangular example) of the bag.

Figure 1 b) is a side view of Figure 1 a).

Figures 1 c) - e) are top views of a sequence of folding and sealing a bag, by means of the known means of figure 1 a).

Figure 2 is an axonometric view of a packaging plant according to the invention.

Figure 3 is a sectioned front view according to a vertical plane of a device for forming and filling packaging bags of the plant of Figure 2.

Figure 4 is the partial section IV-IV of Figure 2.

Figure 5 is a front view of the second conveyor means for the bags of the system of Figure 2, in which the support surface of the bags has been lowered to facilitate understanding of the system.

Figure 6 is a schematic view of the detail VI of figure 5.

Figures 7a and 7b are respective schematic top views of Figure 6 in two operating configurations.

Figure 8 is a schematic view of detail VIII of figure 5.

Figure 9 is the partial section IX-IX of figure 8.

Figures 10 a) and 10 b) are axonometric views of bags obtained by folding by means of said known folding-sealing means of figure 1.

Figure 10 c) is an isometric view of a so-called â € œflyerâ € envelope.

With reference to these figures, the number 1 globally indicates a plant for packaging in bags, in particular, the plant in question is used for packaging in bags of loose food products 100, mainly food products.

As illustrated in figure 3, the plant 1 comprises metering means (per se known and not illustrated) which, through a suitable weighing system, are able to cyclically release a predetermined quantity of food products 100 inside a loading hopper 5 placed over a cylindrical container 2.

In the illustrated embodiment, the plant 1 comprises a forming device, globally indicated with 6, for making envelopes intended for packaging food products 100.

The forming device 6 comprises a vertical forming tube 60, open at both ends, which is positioned below the cylindrical container 2 aligned with the outlet of the loading hopper 5.

Associated with the forming tube 60 is a collar 61 per se known, which is shaped in such a way as to force a strip 200 of flexible film, which slides on it, to orient itself vertically and fold on itself so as to embrace the forming tube 60 by wrapping it.

In practice, the flexible film strip 200 takes the form of a sleeve which wraps the forming tube 60 and which is able to slide vertically on it from top to bottom.

The flexible film is, for example, made of heat-sealable plastic material, but it can also be paper or other material suitable for the formation of bags, and unwinds from a reel, known per se and not illustrated, which is placed upstream of the collar 61.

As illustrated in Figure 4, the flexible film belt 200 is driven in sliding by first conveyor means which comprise, for example, a pair of motorized tracks 62; these motorized tracks 62 are placed on diametrically opposite parts of the forming tube 60 downstream of the collar 61.

The motorized tracks 62 adhere to the flexible film belt 200 by pressing it against the adjacent wall of the forming tube 60 or by means of a suction system, and are operated simultaneously at the same speed, so as to drag the flexible film belt 200 downwards. , consequently causing it to unwind from the reel and slide on the collar 61.

The forming device 6 comprises first sealing means adapted to join together the free vertical edges of the flexible film strip 200 downstream of the collar 61, so as to laterally close the sleeve that said strip 200 forms around the forming tube 60.

Said first welding means schematically comprise a vertical bar 63, which is associated with means suitable for heating it, and is provided with an approaching and distancing movement with respect to the forming tube 60, so as to press against the latter the free edges of the strip 200 by welding them together in correspondence with a zone of mutual overlap.

Finally, bending and welding means are provided underneath the forming tube 60, which are adapted to fold and seal the flexible film strip 200 transversely for a portion of limited thickness, so as to close the bottom of the cylindrical sleeve and thus create ¬ a sort of bag 201 closed at the bottom and open at the top.

Said folding and welding means schematically comprise two opposing bars 64, oriented horizontally and arranged at a certain distance under the forming tube 60, which comprise a shaped wedge (for example of the known type shown in Figure 1) able to bend towards the The flexible film 200 is inside for the conformation of a substantially flat bottom of the bag; these bars 64, moreover, are associated with means suitable for heating them, and are provided with a horizontal movement of reciprocal approaching and distancing, to clamp the flexible film sleeve in a vice and at the same time heat-seal the flexible film.

In use, the tracks 62 advance the flexible film belt 200 by an amount equal to the length of the bag to be obtained, after which the sealing bars 63 stop and the sealing bars 63 are put into action, which achieve the vertical closure of the belt 200. , and the sealing bars 64 which carry out the folding and the lower horizontal sealing of the bag being formed.

The bars 64, unlike known systems, only seal the sleeve of tape 200 of flexible film to form the bottom of the still empty bag which is formed at the end of the forming tube 60 while leaving the full bag open. below, which is immediately separated from the belt 200 by means of suitable cutting means 65 located downstream (below) of the welding and folding means in the direction of advancement imposed on the belt 200 of flexible film by the first conveyor means.

The metering means (not shown) cyclically deliver a dose of products to be packaged 100 into the loading hopper 5, so that each dose rests on the shutter 3 which closes the cylindrical container 2 at the bottom.

When said dose is in the loading hopper 5, the shutter 3 is moved to the open position, causing the products 100 to fall by gravity inside the forming tube 60.

When the shutter 3 is opened, the products 100 fall by gravity into the forming tube 60, collecting themselves in the bag 201 of flexible film which has formed at the lower end of the tube itself.

The products 100 are thus collected inside the bag 201 under the sealing bars 64.

At this point, the cutting means 65, which can be of the type of blades placed below the sealing bars 64, start to cut transversely the strip 200 of flexible film, so as to detach the bag 201 which is thus Open at the top and, at the same time, the sealing bars 64 make available a new bag 201, empty and closed with a flat bottom, at the lower end of the forming tube 60 and the cycle is repeated.

When the cutting means separate the open bag 201 from the overlying belt 200, the filled and open bag 201 falls by gravity onto a support surface 7 intended to support the bag 201 itself resting on its flat bottom.

The plant 1 particularly comprises second conveyor means independent of the first conveyor means and adapted to move the bag 201 (filled with products 100, open and resting on the support surface 7) relative to the forming tube 60, with transverse direction with respect to the longitudinal axis of the same tube.

The second conveyor means comprise a continuous conveyor, which for example moves in steps, of the type of a pocket conveyor 70.

The pocket conveyor 70, on which the filled and opened bags 201 are arranged, is provided with a plurality of pockets with continuous or intermittent continuous movement each carrying a bag 201.

In particular, according to the embodiment illustrated in the figures, the pocket conveyor 70 comprises, in correspondence with its upper branch, a fixed platform 71, with a horizontal and rectilinear longitudinal axis, which defines the support plane 7 extending longitudinally in order to the entire length of the upper branch of the conveyor 70.

A succession of transverse partitions 72,73 slides on the fixed platform 71; the baffles 72, 73 are made to slide on the platform 71, in succession at a constant distance from each other, moved by handling means external to the platform 71. Particularly, the pocket conveyor 70 comprises two groups of baffles 72, 73, that is, a first group of front baffles 72 and a second group of rear baffles 73, which are adapted respectively to be placed upstream and downstream (with respect to the direction of advance imposed by the second conveyor means) of the bag 201 resting on the platform 71 and between each pair of septa 72,73, a pocket is defined which can contain a single bag 201.

In particular, said handling means comprise, for each group of baffles 72,73, a pair of transport chains 74,75, parallel to each other, which form a closed loop conveyor line, the upper branch of which runs alongside and parallel to the platform 71; a regular succession of frames 76 and 77 is fixed to the chains 74,75, each of which carries, respectively, a rear partition 72 and a front partition 73. The chains 74.75 run parallel to the platform 71 and, consequently, the separators 72,73 slide above the same platform dragging with them the bag 201 present in the pocket defined by each pair of adjacent front 72 and rear 73 partitions.

Each of the partitions 72,73 has an inlet wall 78 inclined towards the center of the pocket which acts as a chute for the bag 201 inserted into the pocket, to facilitate its support on the portion of the support surface 7 contained in the pocket, in an upright position.

The guiding walls 78 have adjustment means (known per se, therefore not shown) capable of varying the inclination of the same and the mutual distance according to the shape and size of the bag 201 to be housed in the pocket.

In particular, the means for adjusting the mutual distance between the guiding walls 78 can be constituted by the same chains 74,75, in fact, by varying the phase displacement of the chains 74 with respect to the chains 75 (for example, by activating the rotation of one of the two , when not driven in rotation by the motors at the same time) it is possible to vary the mutual distance between the baffles 72 and 74, with consequent narrowing or widening of the pocket.

The above said cutting means, which make a filled and open bag 201 available, are arranged above the first pocket of the pocket conveyor 70 and are able to make the bag 201 fall onto the portion of the support surface 7 interposed between the invitation walls 78 of the first pocket itself, which is arranged for example at one end of the belt conveyor 70 defining a loading area (the end close to the forming device).

Downstream of this loading area, in the direction of advancement imposed by the belt conveyor 70 on the bags 201, there are arranged in succession a station for flattening the upper end of the bags and a station for closing the flattened upper end and stations finishing and cutting of the closed bag 201, which will be described in greater detail below.

Advantageously, the plant 1 comprises a suction unit 300 equipped with a duct 301 communicating on one side with a blower (not shown in the figures) and at the opposite end presenting a suction mouth 302 which is mobile and suitable for being arranged in correspondence with each aforementioned station, for the suction of production scraps.

The plant 1, in particular the flattening station, comprises flattening means 8 for flattening the open end of the bag 201 with so-called simple folding, i.e. such that the flattened top does not have parts folded towards the inside of the bag , and therefore presents an upper extremity defined by two parallel and rectilinear flaps, facing and bent at the extremities by simple lateral folds.

To carry out this simple folding at the open end of the bag 201, given the shape and folding received by the top of the bag itself during the folding and sealing of the flat bottom of the bag 201 occurring upstream (at the lower end of the forming tube 60), some precautions are necessary, as will become clear in the following.

With reference to figures 6, 7a and 7b, in fact, the flattening means 8 comprise at least one pair of appendages 80, movable in reciprocal approaching and moving away between an approached position and a removed position, suitable for entering the open end of the bag 201 in the approached position and widen the extremal flaps of the bag 201 passing from the approached position to the removed position.

Advantageously, the direction of approach and removal of the appendages 80 is substantially parallel to said transverse direction of advance imposed on the bag 201 by the belt conveyor 70.

Each appendage 80 is moved in translation along this direction of approach and departure by means of a linear actuator 81, for example a double-acting pneumatic jack or an electric motor which drives the appendages in translation by means of return members such as transmission belts or similar members. mechanical.

Furthermore, the pair of appendages 80 is moved in vertical translation, with known means not shown, able to bring the appendages themselves from a raised position in which they do not interfere with the upper end of the bags 201 moving forward on the plane of movement. support 7 and a lowered position in which they are arranged at least partially inserted inside the upper open end (to be widened) of the bag 201.

The flattening means 8 additionally or alternatively comprise a pair of flat walls 82, parallel and movable so as to act as a vice on the open end of the bag 201, flattening it and keeping it flattened while the appendages 80 are extracted and while the the bag itself is introduced into guides 83 located downstream of the flattening means, the function of which will be clarified below. The flat walls 82 are arranged with a longitudinal axis parallel to the transverse direction of advance imposed on the bag 201 by the pocket conveyor 70 and are movable (by known means not shown) in a direction orthogonal to this direction in reciprocal moving away / approaching.

Once the upper end of the bag 201 has been flattened, it will have a greater width (ie dimension along the forward direction) than the width of the flat bottom (in the same direction), with the typical conformation of flyer-type bags.

In particular, the width of the upper end of the bag 201 will be substantially equal to half the perimeter of the upper edge of the bag itself, the upper end of the bag 201 presenting, in fact, simple folding as described above.

Furthermore, the plant 1, as mentioned, comprises a guide 83 (visible in the sectioned detail of Figure 9) defining a horizontal and continuous groove 84 along the portion of the belt conveyor 70 located downstream of the flattening means 8 (in the direction for the advancement of the bags 201) adapted to hold the ends of the bags 201 laterally, keeping it flattened, for the operations of closing and finishing the same.

The plant 1, then, comprises - in correspondence with the aforementioned closing station - sealing means 9 suitable for joining and sealing the folded flaps of the open end of the bag 201.

The sealing means 9 comprise at least one pair of shaped walls 90, for example of the type of further sealing bars, heated and movable so as to act as a clamp on the open end of the bag 201 to close it.

The sealing means 9 can be heat sealing means, for example, with ultrasound, hot blade or hot air flow or gluing means or other types suitable for closing the bags.

Downstream of the closing station there are various finishing stations, globally indicated with the number 10, for the finishing of the bag 201, in which, for example, cutting operations, engraving of notches of various shapes and sizes are carried out according to the requirements before to proceed with the cooling and storage of the closed bags 201.

Obviously, a person skilled in the art can make numerous modifications of a technical-applicative nature to the plant and the packaging method described above, without departing from the scope of the invention as claimed below.

Claims (11)

CLAIMS 1. Plant (1) for packaging products in bags which includes - a forming tube (60) with a substantially vertical longitudinal axis whose upper end is adapted to receive the products (100) to be packaged; - winding means (61) for wrapping a tape (200) of flexible film around the forming tube; - first conveyor means (62) for making the flexible film belt (200) slide along said forming tube (60) in the direction of the longitudinal axis of the forming tube itself; - folding, sealing (64) and cutting (65) means for folding, sealing and cutting the flexible film strip (200) so as to form at the lower end of the forming tube (60) a bag (201) which presents flat bottom comprising a portion of the plane substantially orthogonal to the longitudinal axis of the forming tube (60); characterized by the fact that - the cutting means (65) for cutting the flexible film strip (200) are placed downstream of the folding and sealing means (64) in the direction of advancement of the strip (200), for the realization of an open end of the bag (201) above said flat bottom and by the fact of comprising - a support surface (7) intended to support the open bag (201) resting on its bottom placed under said cutting means and - second conveyor means (70) independent from the first conveyor means (62) and able to move the bag (201), filled with products (100) to be packaged and resting on the support surface (7), relative to the forming (60) with transversal direction with respect to the longitudinal axis of the same. Plant (1), according to claim 1, wherein the second conveyor means (70) comprise a continuous conveyor. 3. Implant (1), according to claim 1, characterized in that it comprises flattening means (8) for flattening the open end of the bag. 4. Plant (1), according to claim 3, in which the flattening means (8) comprise a pair of flat walls (82), parallel and movable so as to act as a clamp on the open end of the bag (201) flattening it. Plant (1), according to claim 4, in which the pair of flat walls (82) are arranged with a longitudinal axis parallel to the transverse direction of advance imposed on the bag (201) by the second conveyor means (70). 6. Plant (1), according to claim 3, in which the flattening means (8) comprise at least a pair of appendages (80), movable in reciprocal approaching and moving away between an approached position and a removed position, suitable for entering the € ™ open end of the bag (201) in the approached position and spread the end flaps of the bag (201) from the approached position to the away position. Plant (1), according to claim 6, in which the direction of approach and removal of the appendages (80) is substantially parallel to said transverse direction of advance imposed on the bag (201) by the second conveyor means (70). 8. Plant (1), according to claim 1, characterized in that it comprises sealing means (9) able to join and seal the open end of the bag (201) to close it. Plant (1), according to claim 8, wherein the sealing means (9) comprise at least a pair of shaped walls (90), heated and movable so as to act as a clamp on the open end of the bag (201 ). 10. Plant (1), according to claims 3 and 8, characterized in that the sealing means (9) are placed downstream of the flattening means (8) with reference to the advancement of the bags (201) along said transversal direction and configured so as to be crossed in series by the open end of the bags themselves. 11. Method for packaging products which includes the steps of - forming a bag (201) equipped with a closed end by means of a substantially flat bottom substantially orthogonal to the longitudinal axis of the bag and an open end arranged above the bottom and - filling the formed bag with products (100), characterized in that it comprises the steps of - move the formed bag (201) sideways, - flatten the open end of the bag (201), by simply overlapping two upper flaps of the same, with respect to a plane parallel to the longitudinal axis of the bag (201) and - close the flattened open end.