TECHNICAL FIELD

The present invention concerns the field of the production of packages of flexible material having one or more rounded corners and one or more indentations for facilitated opening. In particular, the present invention concerns a cutting element for a machine for producing such packages. Moreover, the present invention concerns a machine for producing such packages. Moreover, the present invention concerns a method for producing such packages.

BACKGROUND

Packages or bags of flexible material are widely used to package food products like coffee, grated cheese or flour, pharmaceuticals, detergents, salts, small objects or similar. These packages are for example made with polyethylene-based coupled materials. For example, it is possible to use three-layer materials in which an intermediate layer of aluminium is arranged between a layer of polypropylene that forms the outside of the package and a layer of polyethylene that forms the inside of the package. Moreover, it is also possible to use two-layer materials with a layer of polypropylene that forms the outside of the package and a layer of polyethylene that forms the inside of the package. The use of polyethylene to form the inner surface of the package is particularly advantageous because it allows the package to be welded and thus sealed effectively.

An example of a package of flexible material is shown schematically in figure 1. The figure shows a package 100 of the stand-up type, i.e. comprising a flat base 101 that allows the package 100 to stand in vertical position by resting on the base 101 itself. The package 100 also comprises a first side 1021, a second side 102r and a third side 104 opposite with respect to the base 101. The first side 1021 and the second side 102r have an indentation 1031 and an indentation 103r, respectively, for facilitated opening of the package 100. The indentations for facilitated opening 1031 and 103r are arranged on the first side 1021 and on the second side 102r of the package 100 close to the third side 104. Generally, the user tears the package 100 at one of the indentations for facilitated opening 103r or 1031 so as to open the package 100 and thus gain access to the contents thereof. The indentations for facilitated opening 1031 and 103r indeed facilitate the opening of the package 100 since they form an interruption and thus a weakened and easy-to-tear area along the first side 1021 and the second side 102r of the package.

The package 100 can also optionally comprise a resealable hinge 107 arranged below the indentations for facilitated opening. The resealable hinge 107 makes it possible to reseal the package 100 after it has been opened for the first time through the indentations for facilitated opening.

As can be observed in figure 1 , in the joining area between the first side 1021 and the third side 104 of the package 100 a first sharp edge 1051 is formed. Similarly, in the joining area between the second side 102r and the third side 104 a second sharp edge 105r is formed.

These sharp edges are undesirable, both because they make the appearance of the package not very aesthetically pleasing, and because due to their pointed shape and the materials typically used to form the package they can easily scratch the user in the steps of manipulation of the package.

For these reasons, it is desirable to provide packages comprising rounded corners as shown schematically in figure 2. The package 100' shown in this figure, unlike the package 100 shown in figure 1 , comprises a first rounded corner 1061 in the joining area between the first side 1021 and the third side 104 and a second rounded corner 106r in the joining area between the second side 102r and the third side 104. The presence of the rounded corners 1061 and 106r not only improves the appearance of the package, but also substantially reduces the probability of users being scratched during manipulation of the package 100'.

Packages like those shown in figure 1 can for example be obtained by means of a packaging method and/or system as described in the international patent application published with number WO 03/039963 A1. In particular, the packages can be obtained starting from a reel of flat band of flexible material that is folded and flattened and, through welding and cutting operations, is divided into a plurality of packages that have an opening to be able to be filled.

Figure 3 schematically shows the operative diagram of a machine 200 for producing packages of flexible material with which it is possible to obtain packages 100 like the one shown schematically in figure 1. A band di flexible material N, unrolled for example from a reel not shown in the figures, is folded by the folding station 201. The band N is also coupled with a resealable hinge 107 that is unrolled from the reel 202. The resealable hinge 107 is fixed, for example welded, to the band at the welding station of the closure 203. The station 204 is the formation station of the base for packages of the stand-up type like those shown in figures 1 and 2 (see the base 101 ). The welding means 205 make it possible to weld the band N at regular intervals so as to define the first and second sides of the packages and to thus divide the folded band N into a series of adjacent packages attached to one another. The station 206 is the formation station of the indentations for facilitated opening. In particular, the station 206 can comprise a cutter that makes it possible to form the indentations for facilitated opening on the sides of the packages. The cutter can simultaneously make the indentations for facilitated opening on both sides of two adjacent packages. The cutting station 207 comprises cutting means, for example knives, which make it possible to separate the single packages from the band of adjacent packages. The arrows F indicate the forward direction of the system. In particular, the machine 200 can comprise advancing means 208 that allow the band to be advanced along the forward direction shown by the arrows F. The single packages 100 obtained downstream of the cutting station 207 are empty and open. In particular, with reference to figures 1 and 2, the packages 100 obtained downstream of the cutting station 207 are open along the third side 104 so as to have a mouth through which they can be filled with the desired product. The packages 100 obtained downstream of the cutting station 207 can be stored in a store 209. Alternatively, the packages 100 obtained downstream of the cutting station can be directly fed to a filling machine 210, for example a carousel-type filling machine.

An example of a carousel-type filling machine that can be used to fill and close the packages 100 is shown in the international patent application published with number WO 2008/1 141 13 A1.

Figure 4 schematically shows the operative diagram of a machine 200' for producing packages of flexible material with which it is possible to obtain packages 100' like the one shown schematically in figure 2. The machine 200' shown in figure 4 differs from the machine 200 shown in figure 3 due to the presence of a formation station of the rounded corners 211 arranged downstream of the formation station 206 of the indentations for facilitated opening and upstream of the cutting station 207. The formation station of the rounded corners 211 comprises a cutter 300 structured so as to cut the sharp edges of the packages so as to round them. The station 21 1 can also comprise two cutters, arranged so as to be on both sides of the band N: in this way, it is possible to obtain smoothed edges not only at the third side 104 of the package 100', but also at the base 101.

Examples of cutters for the formation of rounded corners are shown in figures 5a, 6a, 7a and 8a.

Figure 5a schematically shows a horizontal section view of the cutter 300. The figure also shows the band N of adjacent packages. The cutter 300 comprises a projecting element 302. The projecting element 302 comprises a first arched area 304 and a second arched area 305. The arched areas 304 and 305 make it possible to form the rounded corners in the packages 100'. In particular, in the configuration shown in the figures, the arched area 304 makes it possible to form the rounded corner 106ra of the package 100'a arranged on the left in the figures. The arched area 305 makes it possible to form the rounded corner 1061b of the package 100'b arranged on the right in the figures. It should be noted that, since as explained with reference to figure 3, the formation station of the rounded corners 211 comprising the cutter 300 is upstream of the cutting station 207, the two packages 100'a and 100'b are adjacent and attached to one another and to the band N. The two packages 100'a and 100'b are distinguishable through the welds (not shown in the figures) that have been carried out by the welding means 205 of the machine 200'. The two packages will be separated by means of cutting along the cutting line at indicated in the figures.

The figure also shows the cutter that makes it possible to obtain the indentations for facilitated opening 103ra and 1031b.

The figure shows the ideal situation in which the cutting line at exactly meets the tip of the projecting element 302 thus separating the two packages along the ideal separation line that makes it possible to avoid the formation of defects. This is shown by figures 5b, 5c and 5d that show the formation of the two packages 100a and 100b free from defects.

However, the exact positioning of the cutting line at with respect to the cutting carried out by the cutter 300 is problematic.

Figures 6a to 6d show the case in which the cutting line at is moved by x with respect to the ideal position. In this case the packages obtained have defects. For example, the package 100b shown in figure 6d comprises the defect d in the joining area between the rounded corner and the first side of the package. This defect corresponds in practice to a portion of the rounded corner of the package 100a adjacent to the package 100b and is due to the fact that the cutting line between the two adjacent packages was not centred with respect to the tip of the projecting element of the cutter. A defect of this type is unacceptable in terms of aesthetics.

One way to avoid the problem of centring the cutting line at with respect to the tip of the projecting element of the cutter is to widen the tip of the cutter as shown in figures 7a and 8a. However, also in this case the join between the rounded corner and the side of the package is not continuous and homogeneous but has a kind of indentation or step d that, in terms of aesthetics, ruins the appearance of the package. This is clear both in the case in which the cutting line at is centred with respect to the tip of the cutter (figures 7a to 7d), and in the case in which the cutting line at is displaced by x with respect to the centred position (figures 8a to 8d).

A further way to avoid the aforementioned problem is described in patent application EP 2 31 1 61 1 A2. Such a document describes a tool 23 for producing cuts on a sheet of material.

The tool 23 is configured so as to cut the corners of four elements simultaneously and is shaped like a star with four blades 32, 33, 26 and 37. At the tip of each blade there is a widening indicated with the reference numerals 34, 35, 38 and 39. The widenings 34 and 35 are rounded whereas the widenings 38 and 39 have a pointed edge.

The widenings 34 and 35 have a rounded shape so as to prevent the formation of sharp edges in the case in which the tool 23 is not centred exactly along the direction parallel to the side of the bag.

The use of the tool 23 thus gives the big drawback of producing packages comprising incisions on the upper side, as can be clearly seen from figures 7 and 8 of such a document. Such incisions 42 - 45 on the upper side of each bag 24 - 27, however, bring both technical and aesthetic drawbacks.

In light of what is described above, the present invention tackles the problem of producing packages of flexible material with rounded corners that have a good appearance. In particular, the present invention tackles the problem of minimising the defects due to the formation of rounded corners in packages of flexible material.

SUMMARY

The present invention is based on the idea of simultaneously forming, through a continuous cutting line, both one of the rounded corners of the package and the indentation for facilitated opening. In this way, possible errors or imprecisions in cutting are compensated by the shape of the indentation for facilitated opening.

According to an embodiment of the present invention, a cutting element is provided for a machine for producing packages of flexible material comprising at least one rounded corner and an indentation for facilitated opening, the cutting element comprising a main body from which a single projecting element projects, wherein the projecting element projects from the main body at a base area of the projecting element, the base area comprising a first arched area, and wherein the projecting element also comprises an end arranged in the end area of the projecting element and configured so as to form the indentation for facilitated opening so that the cutting element is adapted for forming a first continuous cutting line that defines at least one first rounded corner and an indentation for facilitated opening of a package. The cutting element according to this embodiment makes it possible to simultaneously make, with a single cut along the first cutting line, both the rounded corner and the indentation for facilitated opening of the package. In particular, the first arched area arranged at the base of the projecting element makes it possible to cut and thus form the rounded corner of a package. The end of the projecting element makes "- it possible to cut and thus form the indentation for facilitated opening of the package. Given that the cutting line is defined by the shape of the entire projecting element of the cutter, the rounded corner and the indentation for facilitated opening form simultaneously with a single continuous cut. In this way, the entire cutting of the edge of the package from the rounded corner to the indentation for facilitated opening is continuous, homogeneous and free from defects. Moreover, the fact that there is only one projecting element makes it possible to have a particularly compact cutting element that is easy to make.

According to a further embodiment of the invention, a cutting element is provided in which the base area further comprises a second arched area so that the first cutting line further defines a second rounded corner. For example, the second arched area is opposite to the first arched area so that the first cutting line defines the first rounded corner and the second rounded corner of two adjacent packages in a band from which packages are formed. This promotes the production in series of different packages. In particular, by means of the cutting element and of the cutting line defines by it, the rounded corners of two packages form simultaneously and, at the same time, the undesired formation of defects in the packages is minimised.

According to a further embodiment of the invention, a cutting element is provided in which the end is configured so as to simultaneously form the indentations for facilitated opening in two adjacent packages in a band from which packages are formed. This promotes the production in series of different packages. In particular, by means of the cutting element and the cutting line defined by it, the indentations for facilitated opening of two packages form simultaneously.

According to a further embodiment of the invention, a cutting element is provided in which the projecting element has a length in the range from 15 mm to 30 mm, preferably it is equal to 23 mm. The length of the projecting element defines the distance between the upper side of a package and the indentations for facilitated opening. In practice, the height of the portion of package that is removed by the user to open the package itself is defined. According to a further embodiment of the invention, a cutting element is provided in which the width of a linear portion of the projecting element is in the range from 1 mm to 3 mm, preferably it is equal to 1.5 mm. The width of the linear portion of the projecting element defines the width of the first cutting line in the region between two adjacent packages in a band from which packages are formed.

According to a further embodiment of the invention, a cutting element is provided in which the radius of curvature of the first arched area and/or of the second arched area is in the range from 4 mm to 12 mm, preferably it is equal to 8 mm.

According to a further embodiment of the invention, the cutting element is a cutter, for example a cutter comprising a male element and a female element. Alternatively, the cutting element is a die-punch system. Alternatively, the cutting element is a cutting die.

According to a further embodiment of the invention, a machine for producing packages of flexible material is provided comprising at least one rounded corner and an indentation for facilitated opening wherein the machine comprises at least one cutting element according to embodiments of the present invention. For example, the machine according to the present invention can be a machine of the type defined in the international patent application published with number WO 03/039963 A1 in which a formation station of rounded corners and indentations having facilitated opening is however further implemented, comprising a cutting element according to embodiments of the present invention. The formation station of rounded corners is preferably arranged upstream of the cutting means that make it possible to separate the packages from the band of adjacent packages.

According to a further embodiment of the invention, a machine is provided in which the cutting element is positioned so that the main body of the cutting element at least partially overlaps an outer area with respect to a band of flexible material from which he packages of flexible material are formed. This solution is particularly advantageous since it makes it possible to cut the band of adjacent packages of flexible material along an outer side with respect to the sliding direction of the band. By combining such an embodiment, for example, with a guide configured so as to guide the sliding of the band of adjacent packages, it is possible to obtain a high precision of cut and to have the upper side of the final packages free from incisions. This is because, since the band is in contact both above and below with the sliding guide, the precision of positioning of the cutting element along a direction perpendicular to the sliding direction is very high. Therefore, cutting the band in a lateral position ensures a high precision. On the other hand, in EP 2 31 1 61 1 A2, the band, which is made up of at least two rows of parallel packages, is cut from a central area. In such a document, in order to avoid the uncertainty of positioning along a direction perpendicular to the sliding direction of the band, rounded widenings 34 and 35 have been arranged so as to avoid the formation of sharp edges on the upper edge of the package of flexible material. This, however, gives the drawback of having an upper edge of the package of flexible material that has incisions 42 - 45

According to a further embodiment of the invention, a machine is provided further comprising cutting means arranged preferably downstream of the cutting element in the forward direction of the machine, wherein the cutting means are adapted for separating two adjacent packages along a second cutting line that meets the first cutting line formed by the cutting element. Preferably, the first cutting line and the second cutting line meet at an indentation for facilitated opening. In this way, the tolerance on the position of the second cutting line is increased. In particular, even if the second cutting line is displaced with respect to an ideal position, this imprecision is in any case compensated by the shape of the indentation for facilitated opening so that the appearance of the packages obtained is still good.

According to a further embodiment of the invention, a method for the formation of packages of flexible material comprising at least one rounded corner and an indentation for facilitated opening is provided, wherein the method comprises the following steps: a) formation of the rounded corner through cutting of a band of flexible material having a width equal to the height of the packages of flexible material; b) formation of the indentation for facilitated opening through cutting of the band of flexible material; wherein steps a) and b) are carried out simultaneously in a single cutting step in which a continuous first cutting line that defines the rounded corner and the indentation for facilitated opening is formed in the band of flexible material. Given that the cutting line is continuous and defines the rounded corner and the indentation for facilitated opening, the entire cut of the edge of the package from the rounded corner to the indentation for facilitated opening is continuous, homogeneous and free from defects. Moreover, having the width of the band equal to the height of the packages of flexible material makes it possible to make packages arranged on a single row. This is particularly advantageous since it makes it possible, for example, by making the band slide inside a guide configured so as to guide the movement of the band, to have a high precision of cutting. This is because, since the guide is in contact with the band, it is possible to have a high precision along an axis perpendicular with respect to the sliding direction of the band. Moreover, the fact that there is a single row of packages makes it possible to effectively prevent movements of the band along a direction perpendicular with respect to the sliding direction. Indeed, in the case in which there are more parallel rows, since the material of the packages is a flexible material, there is the risk that such packages can slightly move and thus cause positioning errors of the cutting means. It is clear that when reference is made to the band of flexible material this refers to a band of flexible material ready to be cut to make single packages of flexible material. Therefore reference is made to a band folded into a series of adjacent packages that are attached to one another.

According to a further embodiment of the invention, a method is provided in which the first cutting line further defines a second rounded corner. For example, the first rounded corner and the second rounded corner are, respectively, the rounded corners of two adjacent packages in a band from which packages are formed. This promotes the production in series of different packages. In particular, by means of the first cutting line the rounded corners of two packages form simultaneously and, at the same time, the undesired formation of defects in the packages is minimised.

According to a further embodiment of the invention, a method is provided in which the first cutting line defines the indentations for facilitated opening in two adjacent packages. This promotes the formation of packages in series from a band.

According to a further embodiment of the invention, a method is provided further comprising the following step: separation of two adjacent packages along a second cutting line that meets the first cutting line. Preferably, the first cutting line and the second cutting line meet at an indentation for facilitated opening. In this way, the tolerance on the position of the second cutting line is increased. In particular, even if the second cutting line is displaced with respect to an ideal position, this imprecision is in any case compensated by the shape of the indentation for facilitated opening so that the appearance of the packages obtained is still good.

According to a further embodiment of the present invention, a method is provided in which the cutting device is positioned so as to at least partially overlap an outer area with respect to the band. This solution is particularly advantageous since it makes it possible to cut the band of adjacent packages of flexible material along an outer side with respect to the sliding direction of the band. By combining such an embodiment, for example, with a guide configured so as to guide the sliding of the band of adjacent packages, it is possible to obtain a high precision of cutting and have the upper side of the final packages free from incisions. This is because, since the band is in contact with the sliding guide both above and below, the precision of positioning of the cutting element along a direction perpendicular to the sliding direction is very high. Therefore, cutting the band in a lateral position ensures a high precision. On the other hand, in EP 2 31 1 61 1 A2, the band, which is made up of at least two rows of parallel packages, is cut from a central area. In such a document, in order to avoid the uncertainty of positioning along a direction perpendicular to the sliding direction of the band, rounded widenings 34 and 35 have been arranged so as to avoid having sharp edges on the upper edge of the package of flexible material. However, since there is the drawback of having an upper edge of the package of flexible material with incisions 42 - 45 according to a further embodiment of the invention, a method is provided in which steps a) and b) are carried out by means of a single cutting device, preferably a cutting element according to an embodiment of the present invention.

BRIEF DESCRIPTION OF THE FIGURES

The present invention will be described with reference to the attached figures in which the same reference numerals and/or marks indicate the same parts and/or similar parts and/or corresponding parts of the system.

Figure 1 schematically shows a package of flexible material with sharp edges;

Figure 2 schematically shows a package of flexible material with rounded corners;

Figure 3 schematically shows the operative diagram of a machine for obtaining packages of flexible material with sharp edges;

Figure 4 schematically shows the operative diagram of a machine for obtaining packages of flexible material with rounded corners;

Figure 5a schematically shows a cutter for a machine like the one shown in figure 4;

Figure 5b schematically shows the cutting line obtained with the cutter of figure 5a;

Figures 5c and 5d schematically show details of the packages obtained with the system of figure 5a;

Figure 6a schematically shows the configuration of figure 5a in which, however, the cutting line is displaced with respect to the ideal position;

Figure 6b schematically shows the cutting line obtained with the cutter of figure 6a; Figures 6c and 6d schematically show details of the packages obtained with the system of figure 6a;

Figure 7a schematically shows another cutter for a machine like the one shown in figure 4;

Figure 7b schematically shows the cutting line obtained with the cutter of figure 7a;

Figures 7c and 7d schematically show details of the packages obtained with the system of figure 7a;

Figure 8a schematically shows the configuration of figure 7a in which, however, the cutting line is displaced with respect to the ideal position;

Figure 7b schematically shows the cutting line obtained with the cutter of figure 8a;

Figures 8c and 8d schematically show details of the packages obtained with the system of figure 8a;

Figure 9a schematically shows a cutter for a machine for obtaining packages of flexible material with rounded corners according to an embodiment of the present invention;

Figure 9b schematically shows the cutting line obtained with a cutter like the one shown in figure 9a;

Figures 9c and 9d schematically show details of the packages obtained with the system of figure 9a;

Figure 10a schematically shows the configuration of figure 9a in which, however, the cutting line is displaced with respect to the ideal position;

Figure 10b schematically shows the cutting line obtained with a cutter like the one shown in figure 10a;

Figures 10c and 10d schematically show details of the packages obtained with the system of figure 10a

Figure 1 1 schematically shows the projecting element of a cutter according to an embodiment of the present invention; Figure 12 schematically shows a package obtained with a system based on the present invention;

Figure 13 shows a detail of the package of figure 12;

Figure 14 schematically shows the operative diagram of a machine for obtaining packages of flexible material with rounded corners according to an embodiment of the present invention.

DETAILED DESCRIPTION

Hereinafter, the present invention is described with reference to particular embodiments, as illustrated in the attached tables of drawings. However, the present invention is not limited to the particular embodiments described in the following detailed description and represented in the figures, but rather the embodiments described simply exemplify the various aspects of the present invention, the purpose of which is defined by the claims. Further modifications and variations of the present invention will be clear to those skilled in the art.

Figure 9a schematically shows a cutter 400 for a machine for obtaining packages of flexible material with rounded corners according to an embodiment of the present invention. A portion of band N from which the packages are obtained is also shown. In particular, the details of two adjacent packages 100'a and 00'b that are obtained from the band N are shown. The two packages 100'a and 100'b are attached to one another.

The portion of band N described above is a portion of a band of flexible material ready to be cut to make single packages of flexible material. Therefore, reference is made to a band folded into a series of adjacent packages that are attached to one another. An example of such a band is for example that depicted in figure 3.

The cutter 400 comprises a main body 401 from which a projecting element 402 projects. The projecting element 402 projects from the main body 401 at a base area 403 of the projecting element 402. In other words, the base area 403 of the projecting element 402 is the joining area between the projecting element 402 and the main body 401 of the cutter 400. The base area 403 comprises a first arched area 404 and a second arched area 405.

The arched areas 404 and 405 of the cutter 400 make it possible to form the rounded corners in the packages 100'. In particular, in the configuration shown in the figures, the arched area 404 makes it possible to form the rounded corner 106ra of the package 100'a arranged on the left in the figures. The arched area 405 makes it possible to form the rounded corner 1061b of the package 100'b arranged on the right in the figures.

As can be seen from the figure, the projecting element 402 also comprises an end 406 in its end area, i.e. in the area of the projecting element 402 opposite to the joining base 403 with the main body 401 of the cutter 400. The end 406 of the projecting element 402 is configured so as to form the indentations for facilitated opening in the packages 100'a and 100'b. In particular, the end 406 projects laterally both on the right and on the left with respect to the projection 402 so as to cut both the indentation 103ra in the package 100'a and the indentation 1031b in the package 100'b. The end 406 of the projecting element 402 is thus shaped substantially like an inverted "T". The shapes of the lateral projections of the end 406 can be various, for example pointed, triangular, polygonal, rounded, based on the shape of the indentations for facilitated opening that it is wished to obtain.

Figure 9a also shows the cutting line at that will be made so as to separate the packages 100'a and 100'b. Through the cutting along the cutting line t2 the side 102ra of the package 100'a and the side 1021b of the package 100'b are thus defined.

Figure 9b schematically shows the cutting line t1 obtained with a cutter 400 like the one shown in figure 9a. The cutting line t1 is continuous and defines both the rounded corners of the packages 100'a and 100'b and the indentations for facilitated opening of the two packages. In particular, from left to right in the figure, the cutting line t1 follows the profile of the rounded corner 106ra of the package 100'a, the indentation for facilitated opening 103ra of the package 100'a, the indentation for facilitated opening 1031b of the package 100'b and finally the rounded corner 1061b of the package 100'b. The cutter 400 thus makes it possible to obtain both the rounded corners and the indentations for facilitated opening of the two adjacent packages along the band N from which the packages are produced with a single continuous cutting line t1.

Figure 9b also shows the second cutting line t2 that will, for example, be carried out in a cutting station downstream along the forward direction of the machine with respect to the station comprising the cutter 400. The second cutting line t2 meets the first cutting line t1 made by the cutter 400 at one or both of the indentations for facilitated opening 103ra and 1031b. In particular, the figure shows the ideal situation in which the cutting line t is centred with respect to the two adjacent indentations for facilitated opening of the two adjacent packages. However, it is clear that even if the cutting line t2 was not centred (see for example figures 10a to 10d), the appearance of the packages obtained would only be minimally affected since the possible eccentric position of the cutting line t2 is in any case aesthetically compensated by the depth of the indentations for facilitated opening.

The result is aesthetically beautiful packages given that the rounded corners join in a homogeneous manner to the lateral edges of the packages. An example of such a package is shown in figure 12. It is worth noting the rounded corner 106r of the package 100' and the absence of defects in the joining area between the rounded corner 106r and the side 102r of the package. The package also has the indentation for facilitated opening 103r.

Moreover, this result is obtained without having to implement in an elaborate and thus expensive manner the preciseness in the positioning of the second cutting line t2. In particular, as shown schematically by figures 10a to 10d, even if the cutting line t2 is not perfectly centred, the packages obtained still have a good appearance.

Figure 1 1 schematically shows the projecting element 402 of a cutter according to an embodiment of the present invention. The projecting element comprises a base area 403 and an end 406 opposite to the base area. The base area 403 comprises the first arched area 404 and the second arched area 405. The base area 403 and the end 406 are connected by a linear portion 407 of the projecting element.

The projecting element 402 has a total length L1. The total length L1 can advantageously be comprised in the range from 15 mm to 30 mm. Preferably, the total length L1 is equal to 23 mm.

The linear portion 407 has a width W1. The width W1 can advantageously be comprised in the range from 1 mm to 3 mm. Preferably, the width W1 is equal to 1.5 mm.

The radius of curvature of the first arched area 404 and/or the radius of curvature of the second arched area 405 can be comprised in the range from 4 mm to 12 mm. Preferably, the radius of curvature of the first arched area 404 and/or of the second arched area 405 is equal to 8 mm. As shown in the figure, the first arched area and the second arched area can have the same radius of curvature. Alternatively, the first arched area and the second arched area can have different radii of curvature.

The end 406 of the projecting element 402 is configured so as to form the indentations for facilitated opening in two adjacent packages. The shape of the end 406 shown in the figure is polygonal. However, the end 406 can be of different shapes, for example rounded, elongated, pointed and so on, based on the desired shape for the indentations for facilitated opening. The end 406 has a total width W2 that can be comprised in the range from 4 to 10 mm, for example it can be equal to 6 mm. The end 406 has a length L2 that can be comprised in the range from 2 to 5 mm, for example it can be equal to 3 mm.

Figure 14 schematically shows the operative diagram of a machine M for obtaining packages of flexible material with rounded corners according to an embodiment of the present invention. Unlike the machines 200 and 200' shown in figures 3 and 4, the machine M is provided with a formation station 500 of the rounded corners and of the indentations for facilitated opening comprising a cutter 400 according to embodiments of the present invention. In particular, the machine 200 shown in figure 3 comprises only the formation station of the indentations for facilitated opening 206 and this is not configured to form rounded corners in the packages. The machine 200' shown in figure 4 comprises the formation station of the indentations for facilitated opening 206 and, downstream with respect to it, a subsequent formation station of the rounded corners comprising the cutter 300 shown in figure 5a. The machine M shown in figure 10, on the other hand, comprises a single station in which both the rounded comers and the indentations for facilitated opening are made simultaneously by means of a single cutter.

The other stations of the machine M can correspond to those shown and described with reference to the machines 200 and 200' of figures 3 and 4. In particular, the machine M comprises the cutting station 207 that comprises cutting means, for example knives, which make it possible to separate the single packages from the band N of adjacent packages. The cutting station 207 is arranged downstream of the station 500 that comprises the cutter 400 in the forward direction F of the machine. The cutting station 207 is configured so as to obtain the cutting line t2 shown in figures 9b and 10b.

Moreover, as shown in figure 14, the machine M preferably has rollers that ensure the displacement of the band N along the sliding direction. Moreover, the band N can be contained at the top and bottom by guides (not depicted) that ensure the positioning of the band N since such guides are configured so as to touch both sides (upper and lower) of the band N. Moreover, by adjusting the cutter 400 slightly above the imaginary joining point, even a small vertical displacement of the band does not lead to the formation of an edge.

Based on the present invention, a method for the formation of packages of flexible material is also provided comprising at least one indentation for facilitated opening and at least one rounded corner in the upper end close to the indentation. The method comprises the following steps: a) formation of the rounded corner through cutting from a band of flexible material; b) formation of the indentation for facilitated opening through cutting from a band of flexible material; wherein steps a) and b) are carried out simultaneously in a single step. In particular, the cut from which the formation of the rounded corner is obtained and the cut that allows the formation of the indentation for facilitated opening are carried out at the same moment and are connected so as to form a continuous cutting line, for example the cutting line t1 shown in figure 9b. In other words, a continuous first cutting line that defines the rounded corner and the indentation for facilitated opening is formed in the band of flexible material.

The further steps of the method for the formation of packages can for example be the steps described in detail in the international patent application published with number WO 03/039963 A1. In particular, the method according to the present invention can be a method in which a series of packages of flexible material is obtained from a band of flexible material that is folded and divided into adjacent packages by means of suitable welds as described in WO 03/039963 A1.

Even if the present invention has been described with reference to the embodiments described above, it is clear to those skilled in the art that it is possible to make various modifications, variations and improvements to the present invention in light of the teaching described above and in the attached claims, without departing from the object and scope of protection of the invention.

For example, even if the formation of packages or bags of the stand-up type has been described, the present invention can also be used to form packages or bags that are not of the stand-up type. Moreover, the present invention can be used to form packages with three or four welded sides. Packages with four welded sides are obtained, for example, by overlapping two bands of flexible material instead of folding a single band of flexible material. The present invention can be implemented to form packages of various sizes. Moreover, even if the case in which the packages produced comprise two indentations for facilitated opening and two rounded corners close to them has been shown, the present invention can also be implemented to form packages that comprise a single indentation for facilitated opening and two rounded corners.

The machines for the formation of packages based on the present invention can be of various types, for example linear like those described in WO 03/039963 A1. Moreover, the machines based on the present invention can include or be coupled with systems with stations for filling and closing the packages obtained, for example like the carousel systems described in WO 2008/1 141 13 A1.

The packages obtained based on the present invention can be stored empty or can be directly transferred to a system for filling and closing them.

Packages or bags of flexible material obtained through the present invention can be used to package food products like coffee, grated cheese or flour, pharmaceuticals, detergents, salts, small objects or similar.

The packages obtained through the present invention can be made with polyethylene-based coupled materials. For example, it is possible to use three-layer materials in which an intermediate layer of aluminium is arranged between a layer of polypropylene that forms the outside of the package and a layer of polyethylene that forms the inside of the package. Moreover, it is also possible to use two-layer materials with a layer of polypropylene that forms the outside of the package and a layer of polyethylene that forms the inside of the package. The use of polyethylene to form the inner surface of the package is particularly advantageous because it makes it possible to effectively weld and thus seal the package.

The weight of the layers and, in general, the dimensions of the packages can be various and depend on the amount and volume of the product that must be contained in the packages.

Moreover, even if in the description of the embodiments of the invention reference has been made to a cutter, the cutting element based on the present invention can be of different types known to those skilled in the art. For example, the cutting element can comprise a cutter, for example a male cutter and/or a female cutter. Moreover, the cutting element can comprise a die- punch system. Moreover, the cutting element can comprise a cutting die.

Moreover, it is clear to those skilled in the art that, even if a single projecting element has been defined that projects from the main body, the cutting element can have a plurality of projecting elements, parallel to one another and projecting perpendicular to the sliding direction of the band. This is because, for example, it could be preferable to make many cuts simultaneously to reduce the cutting times. Alternatively, it is possible for example to use many cutting elements arranged at a certain distance along a sliding direction of the band.

Finally, things that are deemed to be known by those skilled in the art have not been described so as to avoid excessively and unnecessarily obscuring the invention described. Consequently, the invention is not limited to the embodiments described above, but is limited by the scope of protection of the attached claims.