APPARATUS AND METHOD FOR PRODUCING A SEALED SINGLE-DOSE BREAK-OPEN PACKAGE

A production method of a sealed single-dose break-open package; wherein the package comprises: a first sheet of semi-rigid plastic; a second sheet of flexible plastic superposed on and sealed to the first sheet to define a sealed pocket that contains a dose of a product; and a weakened zone made in a central zone of the first sheet for guiding, after bending of the package, controlled breaking of the first sheet at the weakened zone to cause formation of an outlet opening for the product through the first sheet; the method includes making in a surface (8, 10) of the first sheet an incision that constitutes the weakened zone; wherein the incision is made through plastic deformation of the material using an incision tool having a tip that is not sharp, that is, that has a round shape for deforming rather than cutting.

TECHNICAL FIELD

The present invention relates to an apparatus and to a production method for producing a sealed single-dose break-open package.

BACKGROUND ART

The patent application WO2008038074A2 describes a sealed single-dose break-open package; the sealed package comprises a sheet of semi-rigid plastic material and a sheet of flexible plastic material which is superposed on and sealed to the sheet of semi-rigid plastic material to form a sealed pocket that contains a dose of a fluid product. The sheet of semi-rigid plastic material has in the central part a weakened zone for guiding controlled breakage of the sheet of semi-rigid plastic material in such a way as to cause the formation of an outlet opening for the product through the sheet of semi-rigid plastic material itself. In other words, to open the sealed package a user must grab the sealed package itself with the fingers of one hand and “V”-bend the sealed package until the sheet of semi-rigid plastic material breaks at the weakened zone. The weakened zone comprises an inner incision that is made through an inner surface (that is, facing the pocket) of the sheet of semi-rigid plastic material and an outer incision that is made through an outer surface of the sheet of semi-rigid plastic material and aligned with the inner incision.

In patent application WO2008038074A2, the incisions vary in depth in order to break the sheet of semi-rigid plastic material progressively during the “V”-bending of the sealed package. However, making incisions that vary in depth is relatively complicated since it requires a very high precision of movement of the blades of the incision unit; amongst others, the precision of movement of the blades of the incision unit tends to decrease with the increase of the operating speed and as a result, to obtain a very high precision of movement of the blades of the incision unit it is not possible to reach particularly high operating speeds.

Moreover, the sealed single-dose package described in patent application WO2008038074A2 does not allow to apply (spread) the product contained inside the package itself in a precise and intuitive manner on a surface and therefore that package is not suitable to contain spreadable products (that is, to be spread on a surface).

To make the package, patent application WO2008038074A2 describes the use of an apparatus including a reel for feeding a strip of semi-rigid material and a reel for feeding a strip of flexible material, an incision unit and a package forming station including a device for feeding the fluid product and a sealing device. The incision unit has two parallel, facing plates, movable towards each other to grip the strip of semi-rigid material, that support some blades. Each plate is pushed towards the other respectively by a linear actuator in order to hold the strip of semi-rigid material and make an incision on each side of the same.

According to an alternative method described in patent application WO2009040629A2, a “V”-shaped incision that varies in depth is made on each side of the strip of semi-rigid plastic material, with a sharper blade on the side of the strip intended for the outer part of the package. The blades are pushed one against the other in order to hold the strip of semi-rigid material and make the incisions on the same. Even through this method, moving the blades turns out to be difficult and it is not possible to control the depth of the incision.

DISCLOSURE OF THE INVENTION

The object of the present invention is to provide an apparatus and a method for producing a sealed single-dose break-open package that are free from the above mentioned disadvantages.

According to the present invention, an apparatus and a method for producing a sealed single-dose break-open package are provided in accordance with the accompanying claims.

Number 1 inFIGS. 1 and 2indicates as a whole a sealed single-dose break-open package. The sealed single-dose package1comprises a rectangular sheet2of semi-rigid plastic material and a rectangular sheet3of flexible plastic material superposed on and sealed to sheet2of semi-rigid plastic material to form (between sheets2and3) a sealed pocket4containing a dose of a fluid product5.

The sheet2of semi-rigid plastic material may have regular or irregular shape and sheet3of flexible plastic material may have regular or irregular shape symmetric to the semi-rigid plastic material.

The sheet2of semi-rigid plastic material has a weakened zone6in the central part for guiding controlled breakage of the sheet2of semi-rigid plastic material in such a way as to cause the formation of an outlet opening for the product5through the sheet2of semi-rigid plastic material. In other words, to open the sealed single-dose package1, a user has to grip the sealed single-dose package1with the fingers of one hand and “V”-bend (as shown inFIG. 3) the sealed single-dose package1until the sheet2of semi-rigid plastic material breaks at the weakened zone6. By breaking the sheet2of semi-rigid plastic material at the weakened zone6, the product5can flow smoothly and hygienically out of the sealed single-dose package1.

According toFIG. 4, the weakened zone6comprises one inner incision7(not passing through, i.e. it does not go completely through the sheet2of semi-rigid plastic material) which is made through an inner surface8(that is, oriented towards pocket4or facing pocket4) of the sheet2of semi-rigid plastic material and a outer incision9(not passing through, i.e. it does not go completely through the sheet2of semi-rigid plastic material) that is made through an outer surface10(that is, opposite to pocket4) of the sheet2of semi-rigid plastic material. The two incisions7and9are identical (that is, shape and dimensions of the inner incision7are equal to the shape and dimensions of the outer incision9), aligned and superposed (that is, the two incisions7and9are placed exactly in the same position on the opposite surfaces8and10of the sheet2of semi-rigid plastic material). The two incisions7and9do not touch, that is, a residual portion of the sheet2of semi-rigid plastic material interposes itself between the two incisions7and9, to preserve the integrity of sealed pocket4. Moreover, the sheet2of semi-rigid plastic material and the sheet3of flexible plastic material in this example of embodiment are made in such a way that incisions7and9determine the required breakage of the sheet2of semi-rigid plastic material when exposed to the forces generated by the “V”-bending (shown inFIG. 3).

According to the example of embodiment illustrated inFIG. 3, the sheet2of semi-rigid plastic material is a laminate and includes an outer supporting layer11(that is, on the side opposite to pocket4in the area of the outer surface10) and an inner supporting layer12(that is, on the side of pocket4in the area of the inner surface8). An insulating or barrier layer13is provided between the two supporting layer11and12to ensure impermeability to air and/or light; in other words, the barrier layer13is enclosed by the two supporting layers11and12and separates the supporting layers11and12itself from one another. The supporting layer12is covered by a heat-sealable layer14which is placed internally (that is, on the same side of pocket4and in contact with sheet3of flexible plastic material to allow the heat-sealing to the sheet3of flexible plastic material itself).

According to some embodiments shown in the attached figures, the two supporting layers11and12may have the same thickness (i.e. are specular or twins); however, according to other embodiments, the two supporting layers11and12may have different thicknesses, i.e. the thickness of supporting layer11is different from thickness of supporting layer12.

As non-limiting example, the sheet2of semi-rigid plastic material may be composed of: a supporting layer11of white polystyrene (PS) with a thickness of 200 micron(±10%), a barrier layer13of “Evoh” or dialuminum with a thickness of 10 micron(±10%), a supporting layer12of white polystyrene (PS) with a thickness of 200 micron(±10%), and a heat-sealable layer14of polyethylene (PE) with a thickness of 50 micron(±10%). Alternatively, supporting layers11and12may be composed of polylactic acid (PLA) preferably biaxially oriented, and/or the heat-sealable layer14may be composed of polypropylene (PP). Polylactic acid (PLA) is generally heat-sealable, therefore when supporting layers11and12are made of polylactic acid (PLA), heat-sealable layer14may be absent since the sheet3of flexible plastic material may be heat-sealed directly to supporting layer12of polylactic acid (PLA). Moreover, when supporting layers11and12are made of polylactic acid (PLA) or polypropylene (PP), it is possible to reduce the thickness of the supporting layers11and12itself since polylactic acid (PLA) and polypropylene (PP) allow to obtain sufficiently rigid supporting layers11and12even with a small thickness. As example, if supporting layers11and12are made of polystyrene (PS), the overall thickness of supporting layers11and12has to be higher than 350-380 micron, while if supporting layers11and12are made of polylactic acid (PLA) or polypropylene (PP) the overall thickness of supporting layers11and12may reach even 200 micron.

Each incision7or9has on the surface (i.e. at the surface of the corresponding supporting layer11or12) a width W that may vary according to the plastic material used to make the supporting layers11and12: with white polystyrene (PS) the width W of each incision7or9may range between 0.5 e 1.5 mm while with biaxially oriented polylactic acid (PLA) or with polypropylene (PP) the width W of each incision7or9may range between 2 and 4 mm. As a result, the width W of each incision7or9when using biaxially oriented polylactic acid (PLA) or polypropylene (PP) is higher than the width W of each incision7or9when using polystyrene (PS). These differences are due to the fact that biaxially oriented polylactic acid (PLA) and polypropylene (PP) become fragile (i.e. easily breakable) when crushed (deformed by compression) as occurs by making incisions7and9and as a result, it is more convenient to have relatively wide incisions7and9to obtain in supporting layers11and12residual parts (i.e. what remains of supporting layers11and12in the area of incision7and9) with a high fragility that helps the breakage of package1when it is “V”-bended (as shown inFIG. 3). According to another embodiment not shown, in the sheet2of semi-rigid plastic material, supporting layer12is absent (i.e. the barrier layer13is directly in contact with heat-sealable layer14) and supporting layer11has a double thickness (i.e. supporting layer12is “embedded” in supporting layer11).

The outer incision9is made through the outer surface10of the sheet2of semi-rigid plastic material and can be made by deforming locally the sheet2of semi-rigid plastic material and in particular the supporting layer11of the sheet2of semi-rigid plastic material; the outer incision9ends before the barrier layer13and therefore it does not affect the barrier layer13itself.

The inner incision7is made in the inner surface8of the sheet2of semi-rigid plastic material and can be executed by deforming locally the sheet2of semi-rigid plastic material and in particular the supporting layer12of the sheet2of semi-rigid plastic material; the inner incision7ends before the barrier layer13and therefore it does not affect the barrier layer13itself.

In the area of the inner incision7the heat-sealable layer14can be deformed or torn (partially or completely); in any case, at the inner incision7there is no sealing of any kind between the sheet2of semi-rigid plastic material and the sheet3of flexible plastic material and therefore the possible local damage of the heat-sealable layer14does not have any consequence.

In a preferred embodiment, the incision7is made only on the inner surface8of the sheet2of semi-rigid plastic material by deforming locally the sheet2of semi-rigid plastic material and in particular the supporting layer12of the sheet2of semi-rigid plastic material; the inner incision7ends before the barrier layer13and therefore it does not affect the barrier layer13itself (FIG. 11).

In some embodiments, the barrier layer13may be located between the two supporting layers11and12to build a barrier for the product inside the sealed pocket4. In some embodiments, the incisions7and9may not affect the barrier layer13. In some embodiments, the barrier layer13may be thick and solid enough to allow a partial penetration of incisions7and9provided that the barrier layer13is designed to maintain its barrier function. In some embodiments, the integrity of barrier layer13of the sheet2of semi-rigid plastic material secures the barrier function and therefore the tightness for the content of the sealed pocket4even in the area of the incisions7and9and therefore the sealed pocket4is suitable to contain also perishable products and/or with controlled bacterial load like food, medicines or cosmetics. During the opening by breakage of the sealed single-dose package1by “V”-bending the sealed single-dose package1(as shown inFIG. 3), it is necessary to break at the weakened area6all the supporting layers11and12, barrier layer13and heat-sealable layer14of the sheet2of semi-rigid plastic material.

In some embodiments, inner incision7and outer incision9may have an essentially constant depth lengthwise (net of the inevitable construction tolerances).

As shown inFIG. 5, each incision7and9(the two incisions7and9are identical to and superposed on each other and therefore not distinguishable inFIG. 5) develops along a single line with broken shape (i.e. a single zig-zag line), that is a line composed of an ordered set of consecutive oriented segments (i.e. such that the second end of a segment matches with the first end of the following segment) and not adjacent (i.e. such that a segment and the following segment do not belong to the same straight line). Moreover, each incision7and9develops along a single line with broken shape (i.e. a single zig-zag line) that is open (i.e. the first end and the last end do not match) and not intertwined (i.e. the sides of the line have no intersection point). According to some embodiments, the segments of the single line with broken shape (i.e. a zig-zag single line) along which incisions7and9develop are essentially parallel or essentially perpendicular and therefore a segment forms always an essentially right angle with the next segment.

Each incision7and9has a “U”-shaped central part15and two lateral parts16that are placed on the opposite sides of the central part15and connected to the central part15itself. The two lateral parts16are constituted of two respective straight line segments that have identical dimension and are aligned with each other (i.e. one lies on the extension of the other). The central part is constituted of a main segment17that is essentially parallel to and offset from (i.e. not aligned) the two lateral parts16and of two joining segments18that are essentially parallel to and offset from each other (i.e. not aligned), are essentially perpendicular to the main segment17and are essentially perpendicular to the two lateral parts16; each joining segment18connects a lateral part16to one end of the main segment17.

On the whole, each incision7and9has a square “Ω” shape (i.e. constituted only of segments essentially parallel or essentially perpendicular to each other).

As better shown in the attached figures, the weakened zone6does not affect the whole width of the sheet2of semi-rigid plastic material, but affects only a central portion of the sheet2of semi-rigid plastic material leaving intact (i.e. without the weakened zone6) two lateral portions of the sheet2of semi-rigid plastic material symmetrically placed on opposite sides of the weakened zone6itself.

According to a possible embodiment, the weakened zone6(i.e. the two superposed incisions7and9) increases as the density of the product5contained in the pocket4of the sealed single-dose package1increases, that is, the weakened zone6(i.e. the two superposed incisions7and9) decreases as the density of the product5contained in the pocket4of the sealed single-dose package1decreases. As a result, the embodiment shown inFIG. 5can be suitable to products with a higher density such as creams or granular products while the embodiment shown inFIG. 6can be suitable to products with a lower density like liquids.

According to different embodiments shown inFIGS. 5-9, the main segment17can be linear, angled (broken) or curved. Likewise, also lateral parts16or joining segments18can be linear, angled (broken) or curved.

According to a possible embodiment shown inFIG. 10, the incisions7and9are made by means of plastic deformation of the material using corresponding incision tools19, each of them having a tip that is not sharp, that is to say, that has a round shape (namely a rounded tip) for deforming rather than cutting the supporting layers11and12of the sheet2of semi-rigid plastic material.

According to a preferred embodiment shown inFIG. 11, only one incision7is made on the inner surface8of the sheet2of semi-rigid plastic material by deforming locally the sheet2of semi-rigid plastic material and in particular the supporting layer12of the sheet2of semi-rigid plastic material; by means of an incision tool19having a tip that is not sharp, that is to say, that has a round shape (namely a rounded tip). In particular, the tip may have different degrees of sharpness and may have any shape according to the product contained in the package.

According to the example of embodiment illustrated in the attached figures, the sealed single-dose package1has a rectangular shape; obviously due to aesthetic reasons the sealed single-dose package1may be shaped differently: rounded, elliptic, “bottle”-shaped, rhomboidal, pentagonal, hexagonal, triangular, squared, “bone”-shaped.

The sealed single-dose package1described above has numerous advantages.

Firstly, the sealed single-dose package1described above is easier and cheaper to produce than a similar known package1(for example of the type described in patent application WO2008038074A2), since the incisions7and9have a constant depth and therefore are easier to be made even with high operating speed.

Moreover, the package1described above allows to dose in a simple and efficient way all kind of fluid (liquid or creamy), powdered or granular products and it is particularly suitable for spreading the product5on a surface thanks to the area of the sheet2of semi-rigid plastic material enclosed by the central part15of the incisions7ad9that can be separated (moved) from the rest of sheet2of semi-rigid plastic material becoming a spatula useful to spread the product5itself. In other words, the central portion on the main segment17, between joining segments18is designed to extend when package1is V-bended, in a trajectory beyond the adjacent structures of the sheet2of semi-rigid plastic material to work as a scoop for spreading the product that comes out from the opening (as shown inFIG. 3).

InFIG. 12, 20indicates an apparatus for the production of a sealed single-dose break-open package1in a embodiment of the present invention.

The apparatus20includes a first feeding unit21of a first strip of semi-rigid plastic material, a second feeding unit22of a second strip of flexible plastic material, an incision unit23to make a deformation in the strip of semi-rigid plastic material and a sealing and filling unit24for sealing at least one portion of the strip of semi-rigid material to a corresponding portion of the strip of flexible material to create pocket4and for filling pocket4.

In the illustrated embodiment, the apparatus20includes furthermore a printing unit25placed between the first feeding unit21of the first strip of semi-rigid plastic material and the incision unit23.

The first feeding unit21comprises a reel211from which a strip of semi-rigid plastic material is unwound. The reel211is preferably driven by a brushless motor. The strip of plastic material has a thickness preferably ranging between 200 micron and 450 micron.

The strip of semi-rigid plastic material goes to the printing unit25that includes at least a thermal transfer printer for printing, on the side of the strip that will form the outer surface of the package, a bar code, a batch indication, etc. . . . The printing unit25includes advantageously a number of printers251,252,253installed in-line.

After the printing unit25, the strip of semi-rigid plastic material moves to the incision unit23, where, according to the invention, occurs a deformation or shaping of the side of the strip that will form the inner surface of the semi-rigid sheet, on which there is the heat-sealing layer.

According to the invention, as shown inFIGS. 13, 14, the incision unit23includes a first plate231and a second pate232opposed to the first plate231, wherein the second plate232includes at least one incision tool19, wherein the incision tool19is movable from a first position far from the first plate231to a contact position with the first plate231to obtain a deformation in the strip of semi-rigid material placed between the first plate231and the second plate232. In particular, the incision tool19has a tip with different degrees of sharpness and may have any shape.

The surface of the first plate231and/or the second plate232is preferably ground. The first plate231represents a supporting surface for the strip to be deformed.

As shown in detail inFIG. 15, the second plate232has at least one micrometer measuring tool191placed on the opposite side from the first plate231, which adjusts the range of the incision tool19. The tool191can be manual or motorized. Preferably, the range of incision tool19is adjusted in relation to the second plate232, and the second plate232is movable in relation to the first plate231, which is fixed.

By means of a linear actuator or a motor, the second supporting plate232of the incision tool19is moved towards the first plate231so that one end of the incision tool19moves according to the preset distance towards the first supporting plate231to create the deformation in the strip of semi-rigid material. In this way the deformation or shaping is made with constant depth.

The end of the incision tool19has advantageously the shape of the incision that has to be made in the sheet of semi-rigid material.

Preferably, the second plate232has a number of incision tools19positioned in line, each one joined with a corresponding micrometer measuring tool191, manual or motorized.

The shaping is made advantageously only on the side of the strip that will become the inner surface8of the semi-rigid sheet2.

In this way it is possible to control exactly the range of the incision tool and therefore the deformation depth, so that the semi-rigid sheet is not damaged by cutting. In particular, if this has an inner barrier layer, making the incision by means of the apparatus according to the present invention allows to control that the barrier does not get damaged.

In fact, it is no longer a matter of controlling a blade during the incision to vary the cutting depth along the strip, but of simply adjusting the range of the incision tool19so that this creates a deformation with constant depth and with a predetermined shape in the inner surface8of the semi-rigid sheet2.

In the embodiment shown inFIGS. 12, 13 and 14, the strip of semi-rigid material fits between the first plate231and the second plate232with an essentially vertical bottom-up direction.

During shaping, the strip stops and leans against the first plate231.

To perform this intermittent operation in an apparatus on continuous cycle, the apparatus20includes advantageously a blocking device26which determines stop and recovery in relation to the continuous cycle. Preferably, the blocking device26allows to change the position of the deformation from the axis of the bag. In the illustrated embodiment, the blocking device26comprises a pair of blocking plates261,262, one movable and the other fixed, placed upstream of the incision unit23, in particular below the first plate231and the second plate232for the shaping, a pair of rubber rollers263,264placed downstream of the incision unit23, in particular above the first plate231and the second plate232, and an active dancer roller265pneumatically or electronically controlled. According to the dimensions set by the user in the software of the apparatus, the dancer roller265has a double function, that is, it allows to determine the length of the bag and the position of the incision from the axis of the bag and to perform a mechanical stop without interrupting the continuous cycle of the apparatus.

After the shaping, the strip of semi-rigid material moves to the sealing and filling unit24, where it is joined to the strip of flexible material coming from a reel221, preferably driven by a brushless motor, of the second feeding unit22. The strip of flexible material has a thickness preferably ranging between 62 micron and 100 micron.

The sealing and filling unit24includes a vertical sealing device241, a filling device246and an horizontal sealing device247.

In the sealing and filling unit24, the bag or the bags is/are heat-sealed, preferably by means of compressed air. Compared to the known devices that use springs, the use of compressed air allows to perform a constant sealing and to reduce maintenance work.

The vertical sealing device241has a first pair of rollers including a first rubber roller242and a second warm roller243both equipped with grooves and a second pair of cold rollers244,245, for riveting the sealing made by the previous pair of rollers242,243, also equipped with grooves and placed below the first pair of rollers242,243in vertical direction.

The horizontal sealing device247has a single rotary sealer, consisting of a pair of rollers including a first rubber roller248and a second warm roller249. The horizontal sealing device246closes the filled packages and at the same time, during the rotation, it constitutes the closed base of the packages that have still to be filled.

In sequence, firstly the vertical seals of the package are made, than the package is filled, than it is closed, creating with the same movement the base for the following package.

The apparatus20includes a cutting unit placed after the sealing and filling unit24, wherein each package is separated from the material exceeding from sealing (scrap). The single packages are then positioned on a belt27, that conveys them to the following step of production.