BAG PACKAGING

Abstract

A pouch-type packaging for packaging pourable contents and having a front wall and rear wall made from at least one flexible packaging film is such that the front wall and the rear wall are joined together via a sealing seam. The sealing seam is extended in a region bordering a sealing zone oriented away from the sealing edge with a free end furthest removed from the sealing edge. The front wall of the pouch exhibits an outer layer on the side directed towards the outside of the pouch. The outer layer and the part of the front wall of the pouch lying under the outer layer delimit a outlet zone for the contents in an area which encloses the free end of the sealing zone and extends to an edge of the sealing edge. The application of pressure produces a tear in the part of the front wall of the pouch lying under the outer layer in the region of the free end of the sealing zone and the contents enter the outlet zone and emerge from the pouch at the edge of the sealing edge.

Description

The invention relates to a pouch-type packaging for pourable contents, having a front wall and rear wall made from at least one flexible packaging film, such that the front wall and the rear wall are joined together via a sealing seam at a sealing edge and featuring a manual aid-to-opening for the purpose of opening the pouch and removing the contents.

Today, mainly flat-pouches or sachets in the form of three-sided and four-sided pouches, or tube-shaped pouches, are used for packaging portions of ketchup, mustard and similar small amounts of products that are in a liquid, partially liquid or paste-like form. The pouches are normally made up of film-type laminates and feature on the outside a printed, possibly lacquer-covered paper layer or a plastic film e.g. of PET, oPP, oPA or cellophane. The plastic film may also bear print deposited using reverse printing.

The opening of these pouches, which are relatively small in view of the small amount of contents, normally takes place by tearing the pouch open. For that purpose, in the region intended for opening, a weakness in the material which serves as a place for initiating the tearing action may be provided e.g. in the form of laser-cut lines which extend over only part of the thickness of the film-type laminate. Another place for initiating tearing is e.g. a tearing notch which is normally situated in a sealing seam. To open the pouch, the pouch is normally gripped at two places between finger and thumb of each hand and the opening achieved by a tearing action which is effected by a relative movement of both hands.

A known aid-to-opening comprises a notch which is introduced in the packaging line in a sealing seam, normally in the finished pouch. Another known aid-to-opening is such that, prior to pouch production, the laminate is weakened locally by means of laser cutting in the intended area of opening. In both cases there is the possibility that the barrier layer present may be damaged or a notch may extend into the non-sealed region. In both cases there is the possibility that an integral barrier layer may be damaged or a notch extends into the non-sealed region.

A further disadvantage of the known aids-to-opening in the form of notches and laser cuts is that, even on carefully tearing open the pouch, some of the contents escapes from the pouch during tearing and unintentionally sticks to the hands.

The object of the invention is to provide a pouch-type packaging of the kind mentioned at the start which exhibits a manual opening system by means of which it is possible to avoid contamination of the hands with contents escaping from the pouch when the opening procedure is correctly carried out.

That objective is achieved by way of the invention in that, in the front wall of the pouch a distance from the sealing seam, a free end of a sealing zone is provid-ed furthest removed from the sealing edge, and at least the front wall of the pouch exhibits an outer layer on the side facing the outside of the pouch, whereby the outer layer and the part of the front wall of the pouch lying under the outer layer delimit an outlet zone for the contents in an area which encom-passes the free end of the sealing zone.

In a first preferred embodiment of the pouch-type packaging according to the invention the sealing seam is extended in a region bordering the sealing edge and the outlet zone up to a sealing zone directed away from the sealing edge, and the outlet zone extends to a peripheral edge of the sealing edge.

In a second preferred embodiment of the pouch-type packaging according to the invention the sealing zone and the outlet zone are arranged a distance from the sealing seam and the outer layer exhibits a line of weakness or a separating line as outlet region for the contents to be poured out of the pouch.

In a first preferred version of the pouch-type packaging according to the invention the outer layer in the outlet zone is bonded to the underlying part of the front wall of the pouch less strongly than it is outside the outlet zone and can be peeled away from that underlying part of the front wall.

In a second preferred version of the pouch-type packaging according to the invention the outer layer in the outlet zone is freed from the part of the front wall of the pouch lying under the outer layer.

In a third preferred version of the first preferred embodiment of the pouch-type packaging according to the invention the outer layer in the outlet zone is freed from the part of the pouch front wall lying under the outer lay up to a region in the sealing edge and is bonded in the region in the sealing edge to the part of the pouch front wall under the outer layer less strongly than outside the outlet zone and can be peeled away from that part of the front wall.

In the first preferred embodiment of the pouch-type packaging according to the invention the sealing zone may be in the form of a triangle with its base lying parallel to the sealing edge and sides forming a peak a distance from the sealing edge. The sealing zone may, however, also be in the form of a strip which preferably runs perpendicular from the sealing edge and exhibits a free end. Usefully, the outlet zone is delimited by two borderlines that run essentially parallel to each other and perpendicular to the sealing edge. The outlet zone may, however, also be delimited by border lines that preferably run towards one end of the sealing seam in the region of a corner of the pouch.

In the second preferred embodiment of the pouch-type packaging according to the invention the sealing zone is likewise preferably in the form of a triangle with its base lying parallel to the sealing edge and sides forming a peak a distance from the sealing edge. Usefully, the outlet zone is delimited by two border lines that run essentially parallel to each other and perpendicular to the sealing edge and two border lines that run essentially parallel to each other and parallel to the sealing edge.

Packaging films that are suitable as front and rear walls of the pouch exhibit a sealing layer on the side that forms the inner facing side of the finished pouch and can be sealed to each other. Thereby, the sealing layer may be bonded to a substrate layer via an adhesive. The sealing layer may, however, also be deposited directly on a substrate layer by means of extrusion coating. Under certain circumstances it is also possible to manufacture a sealing layer and substrate layer by co-extrusion.

The outer layer on the side of the front wall of the pouch which forms the outer layer in the finished pouch is, in the region out with the outlet zone for the contents, permanently joined by means of an adhesive layer to a substrate layer lying under the outer layer.

In the regions within the outlet zone the outer layer can be peeled away from the substrate layer or is not joined to it. If desired, within the outlet zone, the outer layer may be sealed to the substrate layer in a manner that enables separation by peeling only in the region of the sealing edge and, outwith the sealing edge, be free from the substrate layer.

The sealing layer and the substrate layer may form a single common layer. The sealing layer, the substrate layer and the outer layer may also each be in the form of a single layer or be multi-layered.

The sealing layers are normally polyethylenes e.g. LDPE, LLDPE, MDPE and mixtures thereof or co-extruded metallocene polyethylenes and inomers e.g. Surlyn®, or co-extruded films of these materials with PE as substrate layer. For special applications polypropylenes may be employed. The thickness of the sealing layers lie in the range of 10 to 100 μm, preferably 15 to 75 μm.

Suitable substrate layers are foils of metal, in particular aluminium or an alumin-ium alloy. These serve simultaneously as barrier layer against the passage of oxygen, water vapour and aromas. The thickness of the aluminium foil used as a barrier layer for the pouch is approximately 5 to 30 μm, preferably 7 to 15 μm.

Suitable outer layers are biaxial oriented plastic films of polyesters, polypropyl-ene or polyamide. A preferred polyester is PET (polyethylene-terephthalate) preferably with a thickness of 8 to 20 μm, in particular 12 μm. The plastic film employed as outer layer may be printed on the outside and, if desired, be provided with a coating having good sliding properties, or may be counter-printed. Instead of a plastic film, it is possible to employ a paper layer coated with plastic as the outer layer.

Instead of a barrier layer in the form of an aluminium foil it is also possible to employ other barrier layers e.g. thin ceramic layers of silicon oxide and/or aluminium oxide which are deposited by sputtering or by precipitation in vacuum, or plastic films e.g. materials from the series of vinyl alcohols e.g. of ethyl-vinyl-alcohol-polymers or polyvinylidenchloride.

The front wall and the rear wall of the pouch may be of the same material or may be different in their layered structure. Normally, the front and rear walls of the pouch are made of the same packaging film.

The pouch-type forms of packaging according to the invention are in particular 3 and 4 sealing edge pouches and tube-like pouches featuring one longitudinal and two transverse seams. The scope of the invention includes amongst others a packaging whereby the rear wall of the pouch is in the form of a flexible pouch-type container made by thermoforming or cold forming and having a peripheral sealing and the front wall of the pouch is sealed as lid onto the sealing area.

Further advantages, features and details of the invention are revealed in the following description of preferred exemplified embodiments and with the aid of the drawing; this shows schematically in

FIG. 1 a plan view of the front side of a flat pouch with opening system;

FIG. 2 a section through the unopened flat pouch in FIG. 1 along line I-I;

FIG. 3 the section shown in FIG. 2 after opening the flat pouch;

FIG. 4 a perspective view of the tube-shaped pouch in FIG. 1 in the unopened state;

FIG. 5 the tube-shaped pouch in FIG. 4 after opening;

FIG. 6 a plan view of part of the front side of the flat pouch in FIG. 1 with different shapes of outlet zone for the contents;

FIG. 7 a plan view of part of the front side of the flat pouch in FIG. 1 with different shapes of sealing zone;

FIG. 8 a plan view of part of the front side of the flat pouch in FIG. 7 with different shapes the outlet zone for the contents;

FIG. 9 a plan view of part of the front side of the flat pouch in FIG. 7 with variable relationship between the length of the sealing zone and its distance from the sealing edge at the side;

FIG. 10 a graphic representation of the relationship between burst strength and the product of the variables in FIG. 9;

FIG. 11 a first layer structure of a packaging film for the production of a pouch-type packaging;

FIG. 12 a second layer structure of a packaging film for the production of a pouch-type packaging;

FIG. 13 a plan view of the front side of the flat pouch in FIG. 1 with sealing and outlet zones arranged outside the sealing seam;

FIG. 14 removal of contents from the pouch shown in FIG. 13.

Shown in FIGS. 1 and 2 is by way of example a version of pouch-type packaging 10 in the form of a so-called 4-sided sealing edge pouch with four sealing edges 16, 18, 20, 22 arranged in a rectangle; the said pouch is comprised essentially of two facing packaging films forming a front side and a rear side of the pouch. The packaging film forming the front side of the pouch, hereafter referred to as the front wall 12 of the pouch, and the packaging film forming the rear side of the pouch, hereafter referred to as the rear wall 14 of the pouch, are joined together by an essentially strip-shaped sealing seam 24 running round the pouch-type packaging 10 along the sealing edges 16, 18, 20, 22 thus enclosing a space 13 for the contents.

The pouch-type packaging 10 normally contains pourable contents 11, in particular in a liquid, partially liquid or paste-like form. Pouch-type forms of packaging 10 include e.g. the known pouches for delivering portions of ketchup, mustard, mayonnaise and the like foodstuffs as contents 11.

In a region intended for opening the pouch, bordering the sealing edge 16, the strip-shaped sealing seam 24 is extended to a sealing zone 26 in the form of an equilateral triangle with a base line c parallel to the sealing edge 16 and two sides a and b forming a peak 27 a distance e from the sealing edge 16.

The side of the front wall 12 facing the inside of the pouch 10 can be sealed onto the side of the rear wall 14 likewise facing the inside of the pouch 10. The outward facing side of the front wall 12 features an outer layer 28. In an outlet zone 30 for the contents 11 which encloses the peak 27 of the sealing zone 26, the outer layer 28 adheres to the underlying part 29 of the front wall 12 with less adhesive strength or is free from the underlying part 29 of the front wall 12.

In the embodiment shown in FIG. 1 the outlet zone 30 is delimited by a border line 32 running parallel to the sealing edge 16 and two border lines 34, 36 which run parallel to each other and perpendicular the sealing edge 16 and form the transition of the outer layer 28 from the permanent join to the underlying part 29 of the front wall 12 to the separable or non-adhesive join in the outlet zone 30. The border line 32 running parallel to the sealing edge 16—as seen in plan view—is situated a distance f from the peak 27 of the sealing zone 26.

If the pouch 10, filled with contents 11, is pressed from the outside—which in practice is achieved e.g. by pressing the pouch 10 between the thumb and index finger of one hand—then a fold is created in the pouch 10 in such a manner that the tension which acts on the pouch walls that are sealed to each other at the transition from the interior space to the sealing joint, reaches a maximum at the peak 27 of the sealing zone 26. On exceeding the elongation at fracture of the part 29 of the front wall 12 lying under the outer layer 28, which is weakened by the reduced or missing adhesion to the outer layer 28, a rupturing or local separation of this part 29 of the front wall 12 occurs thus creating an opening slit 38 (FIG. 3).

After the local separation of the part 29 of the front wall 12 lying under the outer layer 28 in the region of the peak 27 of the sealing zone, further application of pressure to the pouch 10 causes the contents to be pressed out of the inner space 13 through the opening slit 38 into an intermediate space or channel 40 formed by the part 29 of the pouch front wall 12 and the outer layer 28 in the outlet zone 30 and leaves the pouch 10 through an outlet opening 42, which is formed at an end edge 17 of the sealing edge 16 by part 29 of the front wall 12 lying under the outer layer 28 and the outer layer 28.

The opening mechanism in the pouch-type packaging 10 shown in FIGS. 1 to 3 is shown in greater detail in FIGS. 4 and 5. FIG. 5 shows that, on applying pressure to the pouch 10 held between the index finger 46 and the thumb 48 of one hand 44, contents 11 are expressed at the edge 17 of the sealing edge 16 through the outlet opening 42 formed by the part 29 of the pouch front wall 12 and the outer layer 28. Further, it can be seen from FIG. 5 that the opening in the pouch-type packaging 10 and the removal of the contents 11 takes place by single-handed operation. Thereby, the index finger and thumb effecting the compression of the pouch are situated a distance from the outlet opening such that—as cannot be reliably avoided even on correctly opening conventional pouches—any contamination of the contents is prevented here.

As shown in FIG. 6, in the case of a variant of the pouch-type packaging illustrated in FIGS. 1 to 5, the channel 40 formed by the outlet zone 30 and delimited by two boundary lines 34′, 36′ runs along one side of the triangular-shaped sealing zone 26 to the sealing edge 16, such that outlet opening 42 is situated in a corner of the pouch at the edge 17 of the sealing edge 16.

Shown in FIG. 7 is a further version of a pouch-type form of packaging 10 in accordance with FIG. 1 in which, instead of a triangular sealing zone 26—starting from sealing edge 16 and extending the strip-shaped sealing strip 24—a sealing zone 26′ which projects from the sealing edge 16 or from the strip-shaped sealing seam 24 is provide in the form of a strip with a free end 27′ instead of the triangular peak 27.

Here the free end 27′ of the strip-shaped sealing zone 26′ is, as in the embodiment with the triangular sealing zone 26 shown in FIGS. 1 to 5, enclosed by the outlet zone 30. Also here the outlet zone 30 is delimited by one barrier line 32 running parallel to the sealing edge 1 and two barrier lines 34, 36 running perpendicular to the sealing edge 16.

Shown in FIG. 8 is a version of the example shown in FIG. 7 where the channel 40 formed by the outlet zone 30 and delimited by two border lines 34′, 36′ runs along one side of the strip-shaped sealing zone 26′ to the edge 17 of the sealing seam 16.

Rupture tests were carried out on pouch-type forms of packaging with a strip-shaped sealing zone 26′ that projects from a sealing edge and serves to provide an opening slit in the packaging film, and the rupture strength deter-mined as a function of the distance X of the strip-shaped sealing zone 26′ from a pouch sidewall and of the distance Y of the free end 27′ of the strip-shaped sealing zone 26′ from the sealing edge 16. The packaging film employed for production of 4-sided pouches was a laminate having the following structure:

PET 12 μm/Al 8 μm/PE 70 μm

PET Polyethylenterephthalate

Al Aluminium foil

PE Polyethylene

The same laminate was used for the front wall 12 and for the rear wall 14 of the pouch; the sealing was made with PE onto PE. The circumferential sealing seam 24 and the strip-shaped sealing zone 26′ were produced as corrugated or wave-shaped seal with waves arranged in the direction that the sealing seam 24 runs or in the longitudinal direction of the strip; a flat version of the sealing seam 24 was also made for comparison purposes. The build up of pressure in the pouch until rupture occurred was at a rate of 50 mbar/sec. The results of the rupture tests are presented in table 1 and the calculated product X*Y shown in FIG. 10 as individual values along with the line of regression.

TABLE 1
Rupture trials
	Type of			Pressure at rupture	X * Y
Pouch-No.	seal	Y [mm]	X [mm]	[mbar]	[mm2]
1	corrugated	0	0	937	0
2	corrugated	8	9	703	72
3	corrugated	9	16	663	144
4	corrugated	10	13	740	130
5	corrugated	11	30	428	330
6	corrugated	12	23	461	276
7	corrugated	12	7	798	84
8	corrugated	30	11	299	330
9	corrugated	32	6	777	192
10	corrugated	32	19	297	608
11	corrugated	40	16	261	640
12	flat	0	0	800	0
13	flat	0	0	881	0
14	flat	18	20	467	360
15	flat	41	16	343	656

The rupture trials make it possible to determine in a simple manner the optimum dimensions and arrangement of the strip-shaped sealing zone 26′ required for the lowest possible rupture strength.

Shown in FIGS. 11 and 12 is the make up of two packaging films that are suitable for the manufacture of pouch-type forms of packaging 10.

In the case of the packaging film shown in FIG. 11 a sealing layer 50 is deposited onto the substrate layer 52 on the side of the packaging film that will face the interior of the finished pouch by means of extrusion coating or bonded to the substrate layer 52 by way of a layer of adhesive. The side of the substrate layer 52 facing the outside of the pouch made from the packaging film is permanently bonded to the outer layer 28 by way of a first bonding material 54. In the region foreseen for the outlet zone 30 for the contents 11 the outer layer 28 is either not joined to the underlying substrate layer 52 over a bond-free zone 58, or attached via a second bonding material 56 such that it can be separated by a peeling action. The first bonding material 54 for creating a permanent join is an adhesive based on polyurethane (PU). The second bonding material 56 for creating a separable join is e.g. a hot-melt or a hot-sealing coating. The sealing layer 50 is comprised e.g. of a polyethylene (PE), the substrate layer 52 of an aluminium foil and the outer layer of polyethylene-terephthalate (PET).

The make up of the packaging film in FIG. 12 corresponds to that of the film shown in FIG. 11, except in that here the sealing layer 50 also contains the substrate and is comprised e.g. of a polyethylene.

The same packaging film may be employed for the front wall 12 and the rear wall 14 of the pouch. The deposition of the second bonding material 56 to create the separable regions may take place using a printing process e.g. index printing.

In a further version of the pouch illustrated in FIGS. 1 to 5, shown in FIG. 13, a sealing zone 26″ in the form of an equilateral triangle with base c lying parallel to the sealing edge and two sides a, b forming a peak 27″ facing away from the sealing edge is provided about in the middle of the front wall, a distance from the strip-shaped sealing seam 24. The area of the outlet zone 30 for the contents 11 encloses the whole of the sealing zone 26″ and is likewise on all sides a distance from the sealing edge 16 and the sealing seam 24. Within the area of the outlet zone 30 the outer layer 28 is provided with a line of weakness or separating cut 37 running through the outer layer forming a slit-shaped open-ing for removing the contents 11 of the pouch 10. In the example shown the separating cut 37 runs parallel to the sealing seam 16 and is arranged between the sealing edge 16 and the sealing zone 26″.

In the embodiment shown in FIG. 13 the outlet zone 30 is delimited by two border lines 32, 33 running parallel to the sealing edge 16 and two border lines 34, 36 which run parallel to each other and perpendicular to the sealing edge 16 and form the transition in the outer layer 28 from the permanent attachment to the underlying part 29 of the pouch front wall 12 to the peelable or non-adhesive connection in the outlet zone 30.

The pouch-type packaging 10, shown in FIG. 13, for removal of the contents through the front wall 12 of the pouch 10 has pressure applied to it from outside by folding the pouch and pressing together the two resulting halves of the pouch, which in practice—as shown in FIG. 14—is achieved e.g. using the thumb 48 and index finger 46 of one hand. As already explained in the case of pouch 10 in FIGS. 1 to 5, the folding of the pouch 10 is also performed here in such a manner that the tensile force which acts on the pouch walls that are sealed together reaches a maximum at the transition from the interior 13 to the sealing joint at the peak 27″ of the sealing zone 26″. On exceeding the elong-ation at fracture of that part 29 of the pouch front wall 12 in the outlet zone 30 lying under the outer layer 28—where the bonding of the outer layer 28 is reduced or missing—fracture or local separation of this part 29 of the pouch front wall 12 occurs forming an opening slit 38.

After the local separation of the part 29 of the pouch front wall 12 lying under the outer layer 28 in the region of the peak 27″ of the sealing zone 26″ and continuing to apply pressure to the pouch 10, the contents 11 emerge from the interior 13 through the opening slit 38 in the part 29 of the pouch front wall 12 lying under the outer layer 28 and through the outer layer into the intermediate space or channel 40 in the outlet zone 30 and leave the pouch 10 via the slit-shaped opening formed in the outer layer 28 by the line of weakness or line of separation 37.

By pouch-type packaging is also to be understood packaging in which the rear wall 14 of the pouch is in the form of a flexible container manufactured e.g. by thermoforming or cold forming featuring a peripheral sealing area and where the front wall 12 of the pouch is sealed onto the sealing area as a lid.

Claims

1. A pouch-type packaging, for packaging pourable contents, having a front wall and rear wall made from at least one flexible packaging film, the front wall and the rear wall being joined together via a sealing seam at a sealing edge and featuring a manual aid-to-opening for the purpose of opening the pouch and removing the contents, wherein:in the front wall of the pouch a distance from the sealing seam, a free end of a sealing zone is provided furthest removed from the sealing edge, and at least the front wall of the pouch exhibits an outer layer on the side facing the outside of the pouch, whereby the outer layer and the part of the front wall of the pouch lying under the outer layer delimit an outlet zone for the contents in an area which encompasses the free end of the sealing zone.

2. A pouch-type packaging according to claim 1, wherein in a region neighbouring onto the sealing edge, the sealing seam is extended to a sealing zone pointing away from the sealing edge and the outlet zone extends up to an edge of the sealing edge.

3. A pouch-type packaging according to claim 1, wherein the sealing zone and the outlet zone are arranged a distance from the sealing seam and the outer layer in the area of the outlet zone exhibits a line of weakness or line of separation as outlet for the contents of the pouch-type packaging.

4. A pouch-type packaging according to claim 1, wherein the outer layer in the outlet zone is bonded to the part of the front wall lying under the outer layer with less bond strength than out with the outlet zone and can be separated from this by a peeling action.

5. A pouch-type packaging according to claim 1, wherein, in the outlet zone, the outer layer is free from the part of the front wall lying under the outer layer.

6. A pouch-type packaging according to claim 2, wherein, in the outlet zone, the outer layer is free from the part of the front wall lying under the outer layer up to a region in the sealing edge and, in the region in the sealing edge is bonded to the part of the front wall lying under the outer layer less strongly than outwith the outlet zone and can be separated from this by a peeling action.

7. A pouch-type packaging according to claim 2, wherein the sealing zone is essentially in the form of a triangle with base (c) lying parallel to the sealing edge and a peak formed a distance (e) from the sealing edge by the other two sides (a, b).

8. A pouch-type packaging according to claim 2, wherein the sealing zone is in the form of a strip, which projects from the sealing edge and exhibits a free end.

9. A pouch-type packaging according to claim 2, wherein the outlet zone is delimited by two border lines which run essentially parallel to each other and perpendicular to the sealing edge.

10. A pouch-type packaging according to claim 2, wherein the outlet zone is delimited by two border lines that run towards one end of the sealing edge in the region of a corner of the pouch.

11. A pouch-type packaging according to claim 1, wherein the front wall of the pouch is made up of a sealing layer, a substrate layer, and the outer layer is arranged on the substrate layer.

12. A pouch-type packaging according to claim 11, wherein the sealing layer contains or is of polyethylene (PE), polypropylene (PP), mixtures or co-extrudates of PE and PP, or ionomers.

13. A pouch-type packaging according to claim 11, wherein the substrate layer contains or is of a metal foil.

14. A pouch-type packaging according to claim 11, wherein the outer layer contains or is of a biaxially oriented plastic film of polyester or plastic-coated paper.

15. A pouch-type packaging according to claim 11, wherein the sealing layer contains the substrate layer.