GB2580318A

GB2580318A - Mono material bag with tear-off prevention

Info

Publication number: GB2580318A
Application number: GB1821241.5A
Authority: GB
Inventors: Stonely Carl; Hall Nick
Original assignee: Mondi AG
Current assignee: Mondi AG
Priority date: 2018-12-27
Filing date: 2018-12-27
Publication date: 2020-07-22
Also published as: GB201821241D0

Abstract

The application discloses a flexible pouch which comprises a tear stop 11. The tear stop prevents a tear from propagating through the entirety of the pouch such that an opening may be formed to access the contents without the need of ripping the pouch into separated pieces. The pouch comprises front 1 and back panels which are heat sealed along edges 2, 3 forming seams 4, 5. The seams are of constant width along the entirety of the pouch. The tear stop is located in one of the seams. Preferably, the tear stop is a cut or slit comprising straight and curved portions. Ideally, the pouch comprises a notch for initiating the tear. The pouch may also comprise a closure mechanism 8 for sealing the pouch after already being opened. The pouch ideally is made from a polyethylene PE laminate, comprising a first film layer 10, a sealing layer 16 and barrier layer 17 (see figure 5).

Description

Mono material bac] with tear-off prevention The present invention relates to a film packaging bag comprising a front panel and a back panel which are consisting of a heat-sealable bag film and connected to each other at a first longitudinal edge and a second longitudinal edge, wherein at least the second longitudinal edge comprises a sealing seam usually extending along the full length of the second longitudinal edge and connecting the front panel and the back panel, and wherein a separation or weakening of the heat-sealable bag film is provided as tear stop in a sealed area connecting the front panel and the back panel.

The generic film packaging bag is usually tightly sealed after filling during the production process. The film packaging bag usually comprises a top sealing seam extending perpendicular to the longitudinal edges along a cross direction of the film packaging bag. In the specification, the longitudinal direction corresponds to a height and the cross direction to a width of the film packaging bag or the front panel and the back panel, respectively.

To open the film packaging bag, a user can tear apart the upper most portion of the film packaging bag comprising the top sealing seam. This portion is also referred to as tear-off 20 portion.

According to a common film packaging bag, the tear-off portion is completely removed by a user and must be handled as a separate piece. Accordingly, the tear-off portion can get lost before disposal or during a recycling process of the film packaging bag.

To avoid such drawbacks, generic film packaging bags are provided with a tear stop so that the tear propagation is stopped and a complete removal of the tear-off portion is avoided.

According to EP 1 136 379 B1, JP 2009-255959 A, JP 2014-101141 A, JP 2017-1738 A, JP 2018-43765 A and KR 2016-149166 A, separations in a sealed area connecting the front panel and the back panel are provided as tear stop.

As an alternative, JP 2510801 Y and WO 2018/159509 Al suggest to provide stiffening 35 elements or sections as tear stop.

According to the prior art, rather complicated sealing structures and comparable large sealed areas are provided, wherein the size of the opening is limited and usually significantly smaller than the width of the film packaging bag along its cross direction. Furthermore, a back taper may constrict a complete draining of the film packaging bag.

Against this background, it is an object of the invention to avoid these drawbacks and to 5 provide a film packaging back with a large opening width and filling volume without any protrusion or back taper. It is further an aim of the invention to allow an easy modification of a common film packaging bag to implement a tear stop.

To achieve this object, a film packaging bag according to claim 1 is provided.

Coming from a generic film packaging bag according to the preamble of claim 1, the film packaging bag is characterized in that the sealing seam at the second longitudinal edge comprises a constant width along its full length and that the tear stop is completely provided within the width of the sealing seam. Accordingly, the tear stop is implemented in a very easy manner in a common sealing seam comprising a constant width.

As the tear stop is situated within the sealing seam at the second longitudinal edge, the complete area up to the second sealing seam is suitable as opening with a maximum size. As the sealing seam at the second longitudinal edge comprises a constant width, the 20 filling volume of the film packaging bag does not comprise any protrusions or back taper.

Referring to the usual usage of the film packaging bag according to the invention, a tear is initiated at the first longitudinal edge which can be provided with suitable tear initiating means. After tear initiation, the tear travels along the cross direction of the film packaging bag up to the tear stop. A user recognizes a significant resistance when the tear reaches the tear stop so that the user will usually finish the tear operation. Accordingly, the tear-off portion will remain at the opened film packaging bag.

As the tear stop is provided within the width of the sealing seam, only a comparable small 30 section connecting the tear-off portion with the remaining bag body will remain. Nevertheless, even such a comparable small section is sufficient to hold the tear-off portion on the opened film packaging bag.

This is especially true in case that the tear is deflected by the tear stop to an area or 35 direction with a higher tear strength. To achieve such properties, the heat-sealable film may comprise at least a first film layer with an orientation along the cross direction of the front panel and the back panel. The orientation along the cross direction leads to an anisotropic behavior of the heat-sealable bag film with a significantly lower tear force along the cross direction in comparison to the longitudinal direction.

In case that the heat-sealable film comprises at least a first film layer with an orientation 5 along the cross direction, a straight tear propagation from the first longitudinal edge to the second longitudinal edge can be achieved without the need of a weakening line which is nevertheless optional.

As an example, the first film layer comprises an orientation along a production direction of the first film layer, wherein the first film layer is arranged in such a manner that the production direction of the film layer coincides with the cross direction. An orientation of the first film layer can be easily provided during its production by rollers operating at different speed.

As explained above, a comparable narrow section with width of typically 1 mm to 10 mm holds the tear-off portion on the opened film packaging bag. As an advantage, the tear-off portion can be easily moved and deflected by a user. As an example, a user may fold the tear-off portion to be parallel with the second longitudinal edge.

As an option, the user can also completely remove the tear-off portion in an easy and controlled manner by cutting with a knife or scissors or by exercising a significantly enhanced tear force. Thus the tear-off portion can be intentionally removed, an accidental removal is avoided.

According to the invention, the tear-off portion must usually not be handled as a separate piece and cannot get lost before disposal of the complete film packaging bag.

In addition, after the disposal of the complete film packaging bag even a recycling process can be approved as the complete film packaging bag can be detected and handled as one continuous element. With respect to a single separated and thus comparable small tear-off portion, there would be the risk that it cannot be detected by suitable detection means like a near infrared sensor and/or cannot be reliably removed from a continuous stream of waste material.

Within the scope of the invention, the heat-sealable bag film can be a mono film allowing an easy recycling. Especially in case that the first film layer comprises an orientation along a production direction, the first film layer can be laminated with a separate seal film to form the heat-sealable bag film.

The seal film may comprise a multilayer structure with a barrier layer which is usually provided as an internal layer between further layers. As a suitable barrier layer, EVOH may be provided with a thickness between 2 pm and 10 pm. As an example, such a barrier layer can be arranged in a multilayer structure between layers of polyethylene, wherein additional tie layers may be provided between the internal layer of EVOH and the further layers of polyethylene (PE/tie layer/EVOH/tie layer/PE). The thickness of the complete seal film is typically between 30 pm and 60 pm.

As an example, the first film layer can be provided as a mono layer of polyethylene which is oriented along a production direction (machine direction) of the first film layer. The first film layer may comprise a thickness between 25 pm and 80 pm, especially between 35 pm and 65 pm.

The first film layer and the seal film can be laminated with usual adhesives, wherein polyurethane adhesives, especially solvent free 2K-polyurethane adhesives are preferred.

The typical amount of adhesive is in the range of 0.7 and 3 g/m2 weight per unit area.

When the heat-sealable bag film is produced by lamination, a reverse printing can be provided on an inside surface. According to a preferred embodiment of the invention, the inside surface of the first film layer provided as mono film is printed. Typically, the weight per unit area of such a reverse printing is between 0.5 and 2 g/m2. The reverse printing can be provided in multicolor. Especially, MDO-PE is a suitable substrate for such a reverse printing.

According to a preferred embodiment of the invention, a sealing seam connecting the front panel and the back panel is also provided at the first longitudinal edge, wherein a notch can be provided in the sealing seam at the first longitudinal edge as tear initiating means. Such a notch can be provided as cut, weakening or punching. A cut or weakening is usually provided as straight line running in cross direction. A punching can comprise a triangular shape. At least a cut or punching are preferably provided completely within the width of the respective sealing seam. Thus, the tightness is not degraded by the initiating means and the film packaging bag can be tightly closed.

According to the invention, the tear stop is provided completely within the width of the respective sealing seam of typically between 5 mm and 15 mm.

The tear stop can comprise a length between 8 mm and 30 mm and a width between 2 mm and 8 mm.

According to a first further embodiment, the tear stop is provided as a hole elongated 5 along the longitudinal direction, wherein curved ends can be provided as semicircles.

According to an alternative further embodiment, the tear stop is provided as a cut comprising a first section extending preferably as a straight line essentially in the longitudinal direction and at least one curved end section. Preferably, two curved end sections are provided on both sides of the first section which is then also referred to as middle section.

When the tear reaches the tear stop, the tear is interrupted at the cut, wherein the tear forces are deflected by the curved end sections. According to a preferred embodiment, 15 the at least one curved end section comprises a curvature angle of at least 135 °. The curvature angle may be especially in the range between 165 ° and 225 °.

The further embodiment of the film packaging bag is not limited within the scope of the invention. For example, reclosure means as reclosure stripes extending in the cross 20 direction can be provided below the tear stop.

According to a further preferred feature, a bottom gusset is provided at a bag bottom. The bottom gusset forms a base of the film packaging bag in a stand-up position.

The invention is explained referring to a preferred embodiment of the invention.

It is shown: Fig. 1: A film packaging bag according to the present invention, Fig. 2A the upper part of an alternative embodiment, Fig. 2B the film packaging bag according to Fig. 2A torn open, Fig. 3 the detailed embodiment of a tear stop and tear initiating means provided at the same height at longitudinal edges of the film packaging bag, Fig. 4 a storing arrangement of the film packaging bag, Fig. 5 a layer structure of a heat-sealable bag film.

Fig. 6 a storing arrangement of the film packaging bag in an opened condition.

Fig. 1 shows a film packaging bag comprising a front panel 1 and a back panel which are consisting of a heat-sealable bag film and which are connected to each other at the first longitudinal edge 2 and a second longitudinal edge 3, wherein at both longitudinal edges 2, 3 respective sealing seams 4, 5 connecting the front panel 1 and the back panel are provided.

The film packaging bag shown in Fig. 1 is tightly closed, wherein in addition to the sealing seams 4, 5 at the longitudinal edges 2, 3 a top sealing seam 6 and a bottom 7 comprising a bottom gusset are provided.

The specific embodiment shown also comprises a reclosure strip 8 extending in a cross direction X of the bag.

To open the film packaging bag, a tear-off portion is provided above the reclosure strip 8.

As tear initiating means, a notch 9 is provided in the sealing seam 4 at the first longitudinal edge 2.

A tear starting at the notch 9 propagates along the cross direction X between the top 25 sealing seam 6 and the reclosure strip 8.

To guide the tear along the cross direction X, the heat-sealable bag film comprises a first film layer 10 comprising an orientation along the cross direction X. The structure of the heat-sealable film is described in detail below referring to Fig. 5.

According to the invention, a tear stop 11 is provided within the width of the sealing seam 5 at the second longitudinal edge 3. Both sealing seams 4, 5 extend over the full height of the film packaging bag and comprise a constant width along their full length.

According to the embodiment shown in Fig. 1, the tear stop 11 is provided as a cut which is explained in detail below.

When the tear reaches the tear stop 11, the tear is interrupted and the acting forces are deflected.

Fig. 2A shows an alternative embodiment of the invention. The notch 9 is provided as a 5 punching with a triangular shape. In difference to this, Fig. 1 shows a straight cut running in cross direction X as notch 9.

Furthermore, a different embodiment of the tear stop 11 is shown, wherein the tear stop 11 is provided as a hole elongated along the longitudinal direction Z. Fig. 2A shows that the film packaging bag can be opened easily by removing the tear-off portion, wherein the tear-off portion remains connected with the film packaging bag due to the tear stop 11.

Especially Fig. 2B shows that a comparable narrow section 12 of the sealing seam 5 at the second longitudinal edge 3 remains. Nevertheless, the remaining section 12 is sufficient to keep the tear-off portion connected.

Due to the tear stop 11, the tear is interrupted. Furthermore, the acting forces are 20 deflected into the longitudinal direction Z, wherein the first film layer 10 comprises a significantly higher tear strength in the longitudinal direction Z in comparison to the cross direction X. Fig. 3 shows the detailed embodiment of the notch 9 and the tear stop 11 shown in Fig. 1.

Both sealing seams 4, 5 comprise a width between 5 mm and 15 mm, for example 10 mm. The notch 9 provided as a straight cut in the sealing seam 4 at the first longitudinal edge 2 and may comprise a length of about 5 mm.

The tear stop 11 is completely provided within the width of the respective sealing seam 4, wherein the tear stop 11 comprises a length between 8 mm and 30 mm and a width between 2 mm and 8 mm. Assuming the width of the respective sealing seam 5 to be about 10 mm, the length of the tear stop 11 can for example be 16 mm and the width 4 mm.

Fig. 4 shows that the tear stop 11 provided by an elongated hole or a cut can also be used to store the film packaging bag in a hanging position.

Coming back to Fig. 3, the tear stop 11 provided as a cut comprising a first middle section 13 extending as a straight line in the longitudinal direction Z. Curved end sections 14 are provided on both sides of the middle section 13. In the shown embodiment, the curved end section 14 comprises a curvature angle of about 225 ° Fig. 5 shows a preferred embodiment of the heat-sealable bag film. The heat-sealable bag film comprises the first film layer 10 as mono film which is oriented in production direction, wherein the production direction (machine direction) of the first film layer 10 coincides with the cross direction X. The first film layer 10 can consist of polyethylene (MDO-PE) with a thickness of about 50 pm.

The first film layer 10 is laminated with a solvent free 2K-polyurethane adhesive 15 to a multilayer seal film 16.

The multilayer seal film 16 comprises a barrier layer 17 of EVOH between two layers 18a, 18b of polyethylene.

The seal film 16 can be produced by coextrusion with tie layers 19a, 19b on both sides of the intermediate layer 17.

The intermediate layer 17 of EVOH as barrier can comprise a typical thickness of about 5 pm. A reverse printing is provided at the internal surface of the first film layer 10 connected to the seal film 16.

The heat-sealable bag film comprises more than 90 weight per cent polyethylene so that it can be recycled as a high quality material.

Fig. 6 shows the opened film packaging bag being hung up at the tear-off portion.

Claims

Claims 1. Film packing bag comprising a front panel (1) and a back panel which are consisting of a heat-sealable bag film and connected to each other at a first longitudinal 5 edge (2) and a second longitudinal edge (3), wherein at least the second longitudinal edge (3) comprises a sealing seam (5) connecting the front panel (1) and the back panel, and wherein a separation or weakening of the heat-sealable bag film is provided as tear stop in a sealed area connecting the front panel (1) and the back panel, characterized in that the sealing seam (5) at the second longitudinal edge (3) comprises a constant width 10 along its full length and that the tear stop is provided within the width of the sealing seam (5).
2. Film packaging bag according to claim 1, characterized in that the heat-sealable film comprises at least a first film layer (10) with an orientation along a cross direction (X) 15 of the front panel (1) and the back panel.
3. Film packaging bag according to claim 2, characterized in that the first film layer (10) comprises an orientation along a production direction of the first film layer (10), wherein the first film layer (10) is arranged in such a manner that the production direction 20 of the first film layer (10) coincides with the cross direction (X).
4. Film packaging bag according to claim 2 or 3, characterized in that the first film layer (10) is laminated with a seal film (16) to form the heat-sealable bag film.
5. Film packaging bag according to claim 4, characterized in that the seal film (16) comprises a multilayer structure with a barrier layer (17).
6. Film packaging bag according to one of the claims 1 to 5, characterized in that the heat-sealable bag film comprises at least 90 weight per cent polyethylene (PE).
7. Film packaging bag according to one of the claims 1 to 6, characterized in that a sealing seam (4) connecting the front panel (1) and the back panel is provided at the first longitudinal edge (2), wherein a notch (9) is provided in the sealing seam (4) at the first longitudinal edge (2) as tear initiating means.
8. Film packaging bag according to one of the claims 1 to 7, characterized in that the tear stop (11) is provided as a hole elongated along the longitudinal direction (Z).
9. Film packaging bag according to one of the claims 1 to 7, characterized in that the tear stop (11) is provided as a cut comprising a first section (13) extending in the longitudinal direction (Z) and at least one curved end section (14).
10. Film packaging bag according to claim 9, characterized in that the at least one curved end section (14) comprises a curvature angle of at least 135 °.
11. Film packaging bag according to one of the claims 1 to 10, characterized in that the tear stop (11) is provided in a distance to an upper edge between 5 mm and 15 mm.
12. Film packaging bag according to one of the claims 1 to 11, characterized in that the sealing seam (5) at the second longitudinal edge (3) comprises a width between 5 mm and 15 mm.
13. Film packaging bag according to one of the claims 1 to 12, characterized in that the tear stop (11) comprises a length between 8 mm and 30 mm.
14. Film packaging bag according to one of the claims 1 to 13, characterized in that the tear stop (11) comprises a width between 2 mm and 8 mm.
15. Film packaging bag according to one of the claims 1 to 14, characterized in that reclosure means extending in the cross direction (X) are provided below the tear stop (11).