Method and machine for making a flexible pouch

Abstract

A method and a machine for making a flexible pouch (S) comprising two lateral walls (102, 103) reciprocally joined along a pair of lateral edges (104, 105), a bottom (106) and an upper edge (107) which delimit a containing chamber (C) which is able to receive a product (P), provide to seal a reinforcement layer (101) to a sheet (100) in a first sealing station (18), fold said sheet (100) in half along a folding line coinciding with a longitudinal axis (X) of the sheet (100) in a folding station (25), seal said lateral edges (104, 105) to laterally join said lateral walls (102, 103) in a second sealing station (30), form the pouch (S) in a forming station (34) comprising forming elements (35, 38) shaped in a manner correlated to the shape of the bottom (106).

Description

FIELD OF THE INVENTION

[0001] The present invention concerns a method and a machine for making a flexible pouch or bag starting from a sheet of material, preferably heat-sealable, in which a portion of the pouch is configured to be perforated upon use.

[0002] The pouch can be made of a flexible material, such as a single- or multi-layer material, in particular laminar, and is suitable to contain edible substances that define one or more ingredients for the preparation of liquid, solid, or semi-solid food products, such as for example beverages, soups, sauces, purees, or other similar products.BACKGROUND OF THE INVENTION

[0003] Disposable packages intended to receive and contain the most varied types of bulk products in the solid, liquid or powder state which, by way of example only, can be drugs, cosmetics, supplements, foodstuffs, granules, seeds, creams, detergents or other, are known.

[0004] These packages have to be hermetically sealed so as to guarantee that the products are preserved correctly through time, maintaining the necessary standards of hygiene and cleanliness and avoiding any contamination that could cause their deterioration and degradation.

[0005] The shape and characteristics of these packages vary depending on the intended modes of use. Their opening can be manual, by the user who then consumes the product contained therein, or automated, in the event that the packages can be used inside machines that use the product contained therein for the preparation of a food product.

[0006] There are well known and widespread packages that can be used inside machines for the preparation of beverages, also known in the art, in particular coffee, tea, etc., which contain inside them the ingredient that, after coming into contact with hot water, then allows to obtain the beverage, typically by extraction or infusion. Such machines comprise one or more nozzles that pierce the package in one or more predetermined points in order to deliver hot water therein, which is thus mixed with the ingredient.

[0007] Both substantially rigid packages, in particular conformed as capsules, and also flexible packages, conformed as pouches or bags, are known in the art.

[0008] An example of a flexible package of a known type is disclosed in patent document WO-A1-2022 / 022902, which also discloses a machine to make it.

[0009] The pouch disclosed by WO-A1-2022 / 022902 comprises flexible lateral walls forming a flattened body which has the lateral edges and the upper edge closed through heat-sealing, and a cup-shaped bottom portion suitable to be pierced by the water injection nozzle. This bottom portion comprises a hole configured so that the nozzle can pass through it. Two reinforcement layers are provided, disposed on the internal side of the cup-shaped bottom portion so as to hermetically close the package in correspondence with the hole, which are also configured to be pierced by the nozzle at the time of piercing.

[0010] A machine for making a pouch as the one disclosed by WO-A1-2022 / 022902 is also known from US patent US-B2-11,780,616.

[0011] Both machines, both the one disclosed by WO-A1-2022 / 022902, and also the one disclosed by US-B2-11,780,616, provide to seal a reinforcement element in a predetermined position on the sheet, which is subsequently cut to size and folded so as to form the package.

[0012] After the sheet has been cut to size, it is folded around a shaping punch, provided with suction holes to hold the walls of the folded sheet against it by suction. In this position, while the sheet is folded around the shaping punch, it is then provided to heat-seal the lateral edges of the package using suitable sealing bars. Subsequently, the shaping punch is extracted from the package, and the latter is first filled and then its upper edge, through which the package has been filled with the product, is heat-sealed.

[0013] These machines comprise both parts heated to a high temperature, such as the sealing bars, and also a vacuum system, the vacuum being delivered to the shaping punches in order to hold the folded sheet.

[0014] This makes these machines complex and expensive, both in structure and also in operation, in particular due to the presence of the vacuum system.

[0015] Furthermore, the shaping punch and the sealing bars are disposed on a rotatable carousel, which further increases the complexity since the vacuum system is used to feed moving components, and it is necessary to provide to heat and maintain the temperature of heated bars that are movable.

[0016] There is therefore the need to perfect a method for making a flexible pouch and a corresponding machine for making said pouch that can overcome at least one of the disadvantages of the state of the art.

[0017] In particular, one purpose of the present invention is to develop a method for making a flexible pouch that is simple and effective.

[0018] Another purpose of the present invention is to develop a method for making a flexible pouch that does not require a vacuum system.

[0019] Another purpose is to provide a machine for implementing the aforementioned method for making a flexible pouch that is simpler than prior art machines because it has no movable parts that integrate heated components and / or components that have to be fed by the vacuum system, and which has lower operating costs than the prior art machines.

[0020] Another purpose is to provide a machine for implementing the aforementioned method for making a flexible pouch that is more compact and less bulky than prior art machines.

[0021] The Applicant has devised, tested and embodied the present invention to overcome the shortcomings of the state of the art and to obtain these and other purposes and advantages.SUMMARY OF THE INVENTION

[0022] The present invention is set forth and characterized in the independent claims. The dependent claims describe other characteristics of the present invention or variants to the main inventive idea.

[0023] In accordance with the above purposes, a method is described for making a flexible pouch comprising two lateral walls reciprocally joined along a pair of lateral edges, a bottom and an upper edge which delimit a containing chamber which is able to receive a product. This method overcomes the limits of the state of the art and eliminates the defects present therein.

[0024] According to one aspect of the present invention, the method comprises the steps of: feeding a sheet of material able to form the pouch and a reinforcement layer intended to adhere to a portion of the sheet; cutting the sheet to size as a function of the sizes of the pouch, and cutting the reinforcement layer so as to give it a size correlated to that of the bottom of the pouch; sealing the reinforcement layer to the sheet so that a longitudinal axis of the sheet is an axis of symmetry for both; folding the sheet in half along a folding line that coincides with the longitudinal axis, after the step of cutting the sheet to size, so as to reciprocally overlap the two lateral walls; after the folding step, sealing the lateral edges to laterally join the lateral walls; forming the pouch.

[0025] According to one aspect of the present invention, the step of forming the pouch provides to form the bottom after the step of sealing the lateral edges through the action of forming elements shaped in a manner correlated to the shape of the bottom.

[0026] According to one aspect of the present invention, the step of forming the pouch comprises a step of heating the bottom by means of the forming elements which are able to be selectively heated.

[0027] According to one aspect of the present invention, the step of forming the pouch provides the cooperation of a male element, which defines an internal forming element acting inside the pouch and configured to be introduced inside the containing chamber, and of a female element, which defines an external forming element configured to contact the pouch from the outside in correspondence with the bottom, wherein the male element and the female element are mating in shape so as to couple together in order to shape the bottom.

[0028] According to one aspect of the present invention, before the forming step it is provided to open a mouth of the pouch in correspondence with the upper edge so as to allow the introduction of the forming elements, in particular the male element, into the containing chamber.

[0029] According to one aspect of the present invention, the method provides to hold the pouch from the outside without any action of holding the pouch from the inside, in correspondence with the lateral edges, by means of gripping means, preferably mechanical means such as holding grippers for example, at least in the forming step.

[0030] According to one aspect of the present invention, during the step of forming the pouch, the pouch is held by additional gripping means which hold the pouch from the outside in correspondence with the lateral walls, wherein the relative disposition between the additional gripping means and the gripping means is such that the pouch is held in two directions that are incident on, in particular perpendicular to, each other, the gripping means approaching each other and the additional gripping means moving away from each other, or vice versa, in order to determine the opening of the upper edge.

[0031] According to one aspect of the present invention, after the step of forming the pouch there is provided a step of filling the containing chamber with the product, and a step of sealing the pouch in which additional sealing bars heat-seal the upper edge in order to seal the containing chamber filled with the product and thus seal the pouch.

[0032] Another aspect of the present invention concerns a machine for making a flexible pouch comprising: a feeding station for feeding a sheet of material able to form the pouch in a direction of advance; a preparing station for preparing a reinforcement layer intended to adhere to a predetermined portion of the sheet, in which the reinforcement layer is fed toward the sheet and cut to size so as to assume a size correlated to that of the bottom; a first sealing station for sealing the reinforcement layer to the sheet so that a longitudinal axis of the sheet is an axis of symmetry for both; a folding station in which the sheet is folded in half along a folding line that coincides with the longitudinal axis, so as to overlap the two lateral walls with each other; a second sealing station for sealing the lateral edges to join the lateral walls; a forming station configured to form the pouch.

[0033] According to one aspect of the present invention, the forming station is disposed downstream with respect to the second sealing station with reference to the direction of advance.

[0034] According to one aspect of the present invention, the forming station comprises forming elements shaped in a manner correlated to the shape of the bottom.

[0035] According to one aspect of the present invention, the forming elements comprise both a male element which defines an internal forming element acting inside the pouch and configured to be introduced inside the containing chamber, and also a female element which defines an external forming element and configured to contact the pouch from the outside in correspondence with the bottom, wherein the male element and the female element are mating in shape so as to couple together in order to shape the bottom.

[0036] According to one aspect of the present invention, at least one of either the male element or the female element comprises a heating member and is shaped in such a way as to be mating in shape with the bottom.

[0037] According to one aspect of the present invention, the machine comprises gripping means, preferably mechanical means such as holding grippers for example, associated at least with the forming station to hold the pouch from the outside without any action of holding the pouch from the inside, in correspondence with the lateral edges, and possibly additional gripping means to hold the pouch from the outside, in correspondence with the lateral walls.

[0038] According to one aspect of the present invention, the machine comprises a filling station comprising a conveyor element for filling the containing chamber with the product, and a sealing station, downstream of the filling station with reference to the direction of advance, provided with sealing bars for sealing the upper edge, wherein the filling and sealing stations are disposed downstream of the forming station with reference to the direction of advance.

[0039] Advantageously, the method and machine according to the present invention allow to make flexible pouches simply and effectively, achieving high productivity using a machine that is simpler than known machines in both structure as well as operation.DESCRIPTION OF THE DRAWINGS

[0040] These and other aspects, characteristics and advantages of the present invention will become apparent from the following description of some embodiments, given as a non-restrictive example with reference to the attached drawings wherein: fig. 1 is a simplified, schematic, three-dimensional view showing a production line for making a flexible pouch in accordance with the method according to the present invention, in which both the pouch being made and also some parts of a machine for making the pouch according to the present invention are also visible; fig. 2 is a schematic front view of the production line of fig. 1; fig. 3 is a schematic section view, taken along the section plane III-III in fig. 2, of the flexible pouch made using the production line of fig. 1, in which the pouch is shown in an intermediate production step and in which folding members comprised in the machine according to the present invention are also visible; fig. 3a is a detailed view, enlarged and not to scale, of a portion of the flexible pouch shown in fig. 3; fig. 4 is a schematic lateral elevation view of a forming station comprised in the processing line of fig. 1; fig. 5 is a section of the forming station of fig. 4, taken along the section plane V-V of fig. 4.

[0041] To facilitate comprehension, the same reference numbers have been used, where possible, to identify identical common elements in the drawings. It is understood that elements and characteristics of one embodiment can be conveniently combined or incorporated into other embodiments without further clarifications.DESCRIPTION OF SOME EMBODIMENTS

[0042] We will now refer in detail to the possible embodiments of the invention, of which one or more examples are shown in the attached drawings. Each example is supplied by way of illustration of the invention and shall not be understood as a limitation thereof. For example, one or more characteristics shown or described insomuch as they are part of one embodiment can be adopted or varied on, or in association with, other embodiments to produce another embodiment. It is understood that the present invention shall include all such modifications and variants.

[0043] Before describing these embodiments, we must also clarify that the present description is not limited in its application to details of the construction and disposition of the components as described in the following description using the attached drawings. The present description can provide other embodiments and can be obtained or executed in various other ways. We must also clarify that the phraseology and terminology used here is for the purposes of description only, and cannot be considered as limitative.

[0044] Some embodiments described here concern a machine for making a flexible pouch S, indicated as a whole with reference number 10 in the diagram of fig. 2, and a corresponding method for making such a pouch, as will be described in more detail below.

[0045] The term "flexible" indicates that the pouch yields when subjected to the action of a pressure, even light, since it is formed by non-rigid parts which can be pierced by a suitable piercing nozzle, as will be described in detail below.

[0046] At the end of the production method, the pouch S is hermetically sealed in order to guarantee the correct preservation of the product P contained therein, preserving its organoleptic characteristics and guaranteeing its correct preservation through time.

[0047] The product P is preferably an edible food product, for example a water-soluble powder or a soluble concentrate in liquid or semi-liquid form, or vegetable leaves suitable to be infused in water. By way of a non-limiting example, the pouch S can contain a product P which may be coffee powder, chocolate powder, soups or broths, fruit juices or plant extracts, chopped tea leaves, sauces, creams, purées, dairy products such as powdered milk or liquid cream, or others.

[0048] The pouch S is made starting from a sheet 100 of material of a known type, commonly used in the field of primary packaging of food products, unwound from a first reel R1.

[0049] According to preferred embodiments, the sheet 100 can be a multilayer sheet comprising one or more layers of cellulosic-based material, for example consisting of a preponderant portion of fibrous materials, such as paper or cardboard, coated with a coating layer that renders the package impermeable to oxygen and moisture. For example, the coating layer can comprise silicon oxide and / or aluminum oxide.

[0050] According to possible embodiments, the sheet 100 can be a laminated sheet.

[0051] On the sheet 100 there is applied a reinforcement layer 101 which is unwound in the form of a continuous, flexible strip, from a second reel R2, is cut to size so as to assume a substantially square shape and is sealed onto the sheet 100 in a predetermined position.

[0052] The pouch S comprises two lateral walls 102, 103, which are opposing so as to define a containing chamber C interposed between them, configured to contain the product P.

[0053] The pouch S comprises two lateral edges 104, 105 along which the two lateral walls 102, 103 are reciprocally joined.

[0054] The pouch S comprises a bottom 106 and an upper edge 107, on the opposite side with respect to the bottom 106. The latter can be configured as a cup-shaped bottom or a shaped bottom typical of gusseted bags.

[0055] In the example given here, the bottom 106 is shaped so as to comprise a substantially horizontal flat wall 108 and two inclined walls 109, adjacent to the flat wall 108, on opposite sides with respect to each other, which connect the flat wall 108 to the lateral walls 102, 103 (fig. 5).

[0056] This conformation of the bottom 106 is suitable to give stability to the pouch S, since the bottom 106 is shaped so as to provide the pouch with a transverse thickness able to ensure that the pouch S is able to remain in an upright position stably and autonomously.

[0057] An example of a processing line comprising a plurality of working stations for making the pouch S is described below.

[0058] It is understood that these working stations define the operating stations of the machine 10 in accordance with the present invention, which are able to carry out the steps of the method in accordance with the present invention and can be disposed in a single compartment defined within the machine, or in separate and communicating compartments.

[0059] The machine 10 comprises means for handling the sheet 100 and the pouches S, capable of making them advance between the various working stations, and possibly from one compartment to another. Depending on the spaces available and on the design specifications, the handling means can for example be configured to make the sheet 100 advance while it lies in a horizontal plane and, subsequently, to make the pouches S advance - after the sheet has been folded, as will be described below - lying in vertical planes.

[0060] Such handling means are of a type known in the art and can comprise mechanical members such as, for example, conveyor belts, toothed belts, carousels, wheels or carousels equipped with a plurality of gripping members, such as grippers for example, for holding the pouches firmly during their movement.

[0061] The machine 10 comprises a feeding station 11 in which the sheet of material 100 unwound from the first reel R1 is fed.

[0062] To this end, the machine 10 comprises a drawing roll 12 (fig. 2) for feeding the sheet of material 100 in a direction of advance A.

[0063] During the feed, the sheet of material 100 can at least partly wrap around one or more tensioning rolls 13, only one of which is shown in figs. 1 and 2 by way of a non-limiting example.

[0064] The machine 10 comprises a preparing station 15 for preparing the reinforcement layer 101 in which feeding means, not shown, feed the reinforcement layer 101 unwound from the second reel R2 in a direction indicated by the arrow B in fig. 1. In the example shown, the direction B is perpendicular to the direction of advance A.

[0065] This continuous strip is preferably made of a barrier material that is impermeable to oxygen and moisture, for example aluminum or an alloy thereof.

[0066] The machine 10 comprises cutting members 16, of a known type and comprising a cutting element, such as for example a blade or a shear, for cutting the reinforcement layers 101 to size so as to separate them one by one from the continuous strip. Preferably, the cutting members 16 are disposed in the preparing station 15.

[0067] After it has been cut by the cutting members 16, each single reinforcement layer 101 is fed until it reaches a longitudinal axis X, disposed parallel to the direction of advance A.

[0068] The longitudinal axis X defines a center line axis of the sheet of material 100, and divides it in half in the width direction, that is, in the direction parallel to the direction B.

[0069] Each individual reinforcement layer 101 is positioned on the sheet of material 100 in such a way that the longitudinal axis X is an axis of symmetry for the sheet of material 100 and for the reinforcement layer 101.

[0070] More specifically, each individual reinforcement layer 101 is positioned on the sheet of material 100 in such a position that, once the pouch S has been formed, the reinforcement layer 101 is overlapping with the flat wall 108 of the bottom 106.

[0071] The machine 10 comprises a first sealing station 18, in which a sealing member 19 heat-seals the reinforcement layer 101 onto the sheet of material 100.

[0072] In the example shown, the sealing member 19 comprises a sealing rod 19a, movable bidirectionally with an alternating movement, for example parallel to a vertical axis, and a fixed abutment 19b (fig. 2), disposed below the sheet 100 and cooperating with the sealing rod 19a to heat-seal the reinforcement layer 101. The sealing rod 19a is heated, according to modes known in the art, at least in correspondence with its head end, that is, the end configured to contact the reinforcement layer 101.

[0073] The machine 10 comprises a cutting station 20 where the sheet of material 100 is cut to size according to the measurements that the pouch S being made will require. To this end, the machine 10 comprises a cutting device 22, for example oriented perpendicular to the longitudinal axis X.

[0074] Downstream of the cutting station, the two halves of the sheet of material 100 which are disposed on one side and on the other of the longitudinal axis X define the lateral walls 102, 103 of the pouch S.

[0075] The machine comprises a folding station 25, in which folding members 27 (fig. 3A) fold each lateral wall 102, 103 by about 90°, for example from a substantially horizontal position to a substantially vertical position.

[0076] By way of a non-limiting example, each folding member 27 can comprise a movable folder 28 hinged to a fixed support 29 and capable of completing a rotation of at least 90°, as indicated by the arrow in fig. 3A.

[0077] The machine 10 comprises a second sealing station 30 comprising two pairs of sealing bars 31, each disposed in correspondence with a lateral edge 104, 105 of the pouch S so as to heat-seal the lateral edges and thus laterally close the pouch S. The sealing bars can comprise bars heated to temperatures suitable to determine the heat-sealing of the sheet of material, as well known in the art.

[0078] At this point, the pouch S is closed on three sides: the bottom 106, formed by folding the sheet of material 100 along the longitudinal axis X, the two lateral edges 104, 105 heat-sealed in the second sealing station 30.

[0079] Continuing in the direction of advance A, the pouch S reaches a forming station 34 configured to form the pouch S and prepare it for the subsequent introduction of the products P.

[0080] In particular, the forming station 34 is configured to shape the bottom 106.

[0081] The bottom 106 develops on a surface such as to define, when the pouch S is shaped, the base area of the containing chamber C.

[0082] In accordance with some embodiments, the forming station 34 comprises a shaped male element 35 acting inside the pouch S and mating in shape with the containing chamber C.

[0083] The male element 35 is movable linearly, for example with a bidirectional movement parallel to a vertical axis Z, between a raised position in which it is disengaged with respect to the pouch S, and a lowered position in which it is at least partly inserted inside the pouch S.

[0084] In other embodiments, not shown, the male element 35 can move with a linear motion also parallel to a horizontal axis, or otherwise inclined, as a function of the space available in the machine.

[0085] In the example shown, the male element 35 has a cross-section shaped as a convex polygon, for example the shape of an irregular hexagon with six sides, wherein the two sides parallel to the longitudinal axis X can be longer than the remaining sides.

[0086] The male element 35 has a forming end that has a shape correlated to, in particular mating with, the shape of the bottom 106 of the pouch S to be formed.

[0087] To this end, the male element 35 comprises a flat terminal surface 37a and two inclined surfaces 37b that develop on opposite sides of the flat terminal surface 37a (fig. 5).

[0088] When the male element 35 reaches the end of its stroke, in contact with the bottom 106, the flat terminal surface 37a is disposed on the flat wall 108, onto which the reinforcement layer 101 has previously been sealed, and the inclined surfaces 37b are disposed in contact with the inclined walls 109 of the bottom 106.

[0089] Unlike the solutions known in the art, it can be observed that the male element 35 is free of holes, not being connected to any vacuum system.

[0090] The forming station 34 comprises gripping means configured to hold the pouch S at least in correspondence with the lateral edges 104, 105 so as to determine the opening of the pouch S and guarantee access to the containing chamber C.

[0091] In the example given here, the gripping means are means of a mechanical nature and comprise a pair of grippers, schematized in the drawings and indicated with reference number 36.

[0092] According to further embodiments, not shown, the gripping means comprise an additional pair of gripping members, for example configured as suitable mechanical members, which cooperate with the grippers 36 to hold the pouch S also in correspondence with its lateral walls 102, 103. In this case, the grippers 36 and the additional pair of gripping members act on the pouch S in two directions that are incident on, preferably perpendicular to, each other.

[0093] The grippers 36 are configured to hold the pouch S and to perform a movement in which they reciprocally approach each other, moving toward the vertical axis Z, so as to determine the opening of the pouch. In the event that the additional pair of gripping members is also provided, while the grippers 36 are approaching the vertical axis Z, this additional pair of gripping members performs a movement in which one member moves away from the other, so that both move away from the vertical axis Z.

[0094] It is understood that many other embodiments of the aforementioned gripping means can be provided, all technically equivalent to those described above and falling within the scope of the present invention.

[0095] For example, in accordance with other possible example embodiments, in the event that the material that constitutes the pouch has magnetic properties, the second gripping means can comprise magnetic-type holding means, possibly combined with the action of means of a mechanical nature.

[0096] The forming station 34 further comprises a female element 38 acting outside the pouch S and configured to cooperate with the male element 35.

[0097] In the example described here, the female element 38 comprises a heating member 38a, for example an electrical resistance or other suitable similar elements, configured to heat the bottom 106 and stabilize its shape.

[0098] In other embodiments, not shown, in addition or as an alternative to the heating member 38a provided in the female element 38, an additional heating member can be provided, integrated in the male element, for example in proximity to the surfaces 37a, 37b.

[0099] We must clarify that the heating of the bottom 106 can also support the action of permanent adhesion, through heat-sealing, of the reinforcement layer 101 that has been previously sealed onto the sheet of material 100 in the first sealing station 19, thanks to the heat delivered by the heating member 38a.

[0100] The female element 38 is mating in shape with the bottom 106.

[0101] In the example given here, the female element 38 is configured as a heated head shaped in such a way as to comprise a substantially horizontal top wall 39 and two inclined walls 40, on opposite sides with respect to each other with reference to the top wall 39.

[0102] The top wall 39 contacts the flat wall 108 at the lower part, thus contacting it on the opposite side with respect to the side of such wall on which the reinforcement layer 101 has previously been heat-sealed.

[0103] Each inclined wall 40 contacts, or is disposed in proximity to, a respective inclined wall 109 of the bottom 106.

[0104] The machine 10 also comprises a filling station 42 for filling the containing chamber C with the desired product through the upper edge 107, that is, the only edge of the pouch S still open, and a sealing station 45 configured to seal, for example by sealing, the upper edge 107.

[0105] The filling station 42 comprises a conveying element 43, for example configured as a duct or a hopper, to lead the product P, for example by gravity, into the containing chamber C.

[0106] In the filling station 42 the pouch S is preferably still held by the holding grippers 36, and possibly by the additional pair of gripping means, if present, to keep the mouth of the pouch S open and facilitate the operations of filling the containing chamber C.

[0107] The sealing station 45 comprises additional sealing bars 46, for example similar to the sealing bars 31, to heat-seal the upper edge 107 and thus seal the pouch S after it has been filled with the product P.

[0108] The method for making a flexible pouch S that can be implemented by the machine described above is described below.

[0109] The sheet 100 is unwound from the first reel R1 and fed in the direction of advance A. The reinforcement layer 101 is unwound from the second reel R2 and fed in the direction B where it encounters the preparation station 15, in which each single reinforcement layer 101 is separated from the continuous strip through the action of cutting members 16 that cut it to size.

[0110] The reinforcement layers 101 thus singularized advance until they reach the longitudinal axis X in such a position that this axis is a longitudinal axis of symmetry for the sheet 100 and the reinforcement layers 101. Subsequently, the reinforcement layers 101 are sealed onto the sheet in the first sealing station 18, after which the sheet 100 is cut to size in accordance with the sizes of the pouch S in the cutting station 20.

[0111] The sheet cut to size arrives at the folding station 25, in which folding members 27 rotate each half of the sheet by about 90°, folding it book or U-shaped. By doing so, the two lateral walls 102, 103 of the pouch S are parallel and side by side to each other, separated by a hollow space intended to define the containing chamber C.

[0112] Subsequently, the sheet thus folded arrives at the second sealing station 30 in which sealing bars 31 heat-seal the lateral edges 104, 105, so as to close the pouch S on three sides, leaving an opening only in correspondence with the upper edge 107.

[0113] The forming step is then provided, in which the pouch S is opened, with the aid of the gripping means 36 and any additional gripping means, to allow the insertion of the male element 35 inside the containing chamber C. At the same time, the female element 38 is brought into contact with the bottom 106 from the outside of the pouch S (that is, from below in the example shown) to shape and stabilize the shape of the bottom 106.

[0114] Thanks to the mating shape of the male element 35 and female element 38, in this condition they squash the bottom 106, which is interposed between them, from opposite sides. Thanks to the conformation of the male element 35 and the female element 38, in this coupling condition the flat terminal surface 37a and the top wall 39 form the flat wall 108, while the inclined surfaces 37b and the inclined walls 40 form the two inclined walls 109.

[0115] Subsequently, the pouch S is filled with the product P in a filling station 42 and sealed in a subsequent sealing station 45, where sealing bars 46 heat-seal the upper edge 107 so as to hermetically seal the pouch S filled with the product P.

[0116] It is clear that modifications and / or additions of parts or steps may be made to the method for making a flexible pouch and to the corresponding machine for making such pouch as described heretofore, without thereby departing from the field and scope of the present invention, as defined by the claims.

[0117] It is also clear that, although the present invention has been described with reference to some specific examples, a person of skill in the art will certainly be able to achieve many other equivalent forms of a method for making a flexible pouch and of a corresponding machine for making such pouch, having the characteristics as set forth in the claims and hence all coming within the field of protection defined thereby. In the following claims, the sole purpose of the references in brackets is to facilitate reading and they must not be considered as restrictive factors with regard to the field of protection claimed in the specific claims.

Claims

1. Method for making a flexible pouch (S) comprising two lateral walls (102, 103) respectively joined along a pair of lateral edges (104, 105), a bottom (106) and an upper edge (107) which delimit a containing chamber (C) which is able to receive a product (P), comprising the steps of: - feeding a sheet (100) of material able to form said pouch (S) and a reinforcement layer (101) able to adhere to at least one predetermined portion of said sheet (100); - cutting said sheet (100) as a function of the sizes of the pouch (S) and cutting said reinforcement layer (101) so as to give it a size correlated to that of the bottom (106) of the pouch (S); - sealing said reinforcement layer (101) to said sheet (100) so that a longitudinal axis (X) thereof is an axis of symmetry for both; - folding said sheet (100) in half along a folding line coinciding with said longitudinal axis (X) so as to reciprocally overlap the two lateral walls (102, 103); - sealing said lateral edges (104, 105) to join said lateral walls (102, 103) and - forming said pouch (S), characterized in that the step of forming said pouch (S) provides to form said bottom (106) after the step of sealing said lateral edges (104, 105) through the action of forming elements (35, 38) shaped in a manner correlated to the shape of said bottom (106).

2. Method as in claim 1, characterized in that the step of forming said pouch (S) comprises a step of heating the bottom (106) by means of said forming elements (35, 38) which are able to be selectively heated (C).

3. Method as in claim 1 or 2, characterized in that the step of forming said pouch (S) provides the cooperation of a male element (35), which defines an internal forming element acting inside said pouch (S) and configured to be introduced inside said containing chamber (C), and of a female element (38), which defines an external forming element, configured to contact said pouch (S) from the outside in correspondence with said bottom (106).

4. Method as in claim 3, characterized in that said male element (35) and said female element (38) are mating in shape so as to couple together in order to shape said bottom (106).

5. Method as in any claim hereinbefore, characterized in that before the step of forming said pouch (S) it is provided to open a mouth of said pouch (S) in correspondence with said upper edge (107) to allow the introduction of said forming elements (35) into said containing chamber (C).

6. Method as in any claim hereinbefore, characterized in that it provides to hold the pouch (S) from the outside without any action of holding the pouch (S) from the inside, in correspondence with said lateral edges (104, 105), by means of gripping means (36) at least in said forming step.

7. Method as in claim 6, characterized in that said gripping means comprise a pair of holding grippers (36).

8. Method as in claim 6 or 7, characterized in that during the step of forming said pouch (S), the pouch (S) is held by additional gripping means which comprise an additional pair of mechanical gripping members to hold the pouch (S) from the outside in correspondence with the lateral walls (102, 103), wherein the relative disposition between said additional gripping means and the gripping means (36) is such that the pouch (S) is held in two directions that are incident on, in particular perpendicular to, each other.

9. Method as in claim 8, characterized in that it is provided that the gripping means (36) approach each other and said additional gripping means move away from each other, or vice versa, in order to determine the opening of said upper edge (107).

10. Method as in any claim hereinbefore, characterized in that after the step of forming said pouch (S) there is provided a step of filling said containing chamber (C) with said product (P), and a step of sealing said pouch (S) in which additional sealing bars (46) heat-seal said upper edge (107) in order to seal said containing chamber (C) and thus seal said pouch (S).

11. Machine (10) for making a flexible pouch (S) comprising two lateral walls (102, 103) reciprocally joined along a pair of lateral edges (104, 105), a bottom (106) and an upper edge (107) which delimit a containing chamber (C) which is able to receive a product (P), wherein said machine comprises: - a feeding station (11) for feeding a sheet (100) of material able to form said pouch (S) in a direction of advance (A); - a preparing station (15) for preparing a reinforcement layer (101) intended to adhere to a predetermined portion of said sheet (100), in which said reinforcement layer (101) is fed toward said sheet (100) and cut to a size correlated to that of said bottom (106); - a first sealing station (18) for sealing said reinforcement layer (101) to said sheet (100) so that a longitudinal axis (X) of said sheet (100) is an axis of symmetry for both; - a folding station (25) in which said sheet (100) is folded in half along a folding line that coincides with said longitudinal axis (X), so as to overlap the two lateral walls (102, 103) with each other; - a second sealing station (30) for sealing said lateral edges (104, 105) to join said lateral walls (102, 103); - a forming station (34) configured to form said pouch (S), characterized in that said forming station (34) is disposed downstream with respect to said second sealing station (30) with reference to said direction of advance (A) and in that said forming station (34) comprises forming elements (35, 38) shaped in a manner correlated to the shape of said bottom (106).

12. Machine (10) as in claim 11, characterized in that said forming elements (35, 38) comprise both a male element (35) which defines an internal forming element acting inside said pouch (S) and configured to be introduced inside said containing chamber (C), and also a female element (38) which defines an external forming element and configured to contact said pouch (S) from the outside in correspondence with said bottom (106), wherein said male element (35) and said female element (38) are mating in shape so as to couple together in order to shape said bottom (106).

13. Machine (10) as in claim 11 or 12, characterized in that at least one of either said male element (35) or said female element (38) comprises a heating member (38a) and is shaped in such a way as to be mating in shape with said bottom (106).

14. Machine (10) as in any one of claims from 11 to 13, characterized in that it comprises gripping means (36), preferably mechanical means such as holding grippers for example, associated at least with said forming station (34), to hold the pouch (S) from the outside without any action of holding the pouch (S) from the inside, in correspondence with said lateral edges (104, 105), and possibly additional gripping means to hold the pouch (S) from the outside, in correspondence with said lateral walls (102, 103).

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