EP2668111B1

EP2668111B1 - A pouch with laser scoring

Info

Publication number: EP2668111B1
Application number: EP12700344.0A
Authority: EP
Inventors: Sunil Mukund GHASKADVI; Prajakta SAWANT
Original assignee: Unilever PLC; Unilever NV
Current assignee: Unilever PLC; Unilever NV
Priority date: 2011-01-28
Filing date: 2012-01-16
Publication date: 2015-03-11
Anticipated expiration: 2032-01-16
Also published as: WO2012100996A1; CN103328344A; BR112013018495A2; ES2539374T3; CN103328344B; ZA201304929B; EP2668111A1; BR112013018495B1; CL2013002160A1

Description

FIELD OF INVENTION

The present invention relates to a pouch for packaging, particularly to a pouch with lines of weakness so that the pouch may be opened easily.
The invention has been developed primarily for use in detergents and will be described hereinafter with reference to this application. However, it will be appreciated that the invention is not limited to this particular field of use.

BACKGROUND AND RELATED ART

Any discussion of the prior art throughout the specification should in no way be considered as an admission that such prior art is widely known or forms part of the common general knowledge in the field.
Flexible pouches (also called sachets or bags) are used for packaging a variety of products. Most pouches are made and filled on form-fill-seal (FFS) machines. Pouches are made of films that have strength to resist any damage during transportation, storage, and handling.
Pouches need to be opened to empty the contents. However, some pouches are difficult to open, either because the seals are very strong, or because the plastic film is tough. This may be further complicated when either the pouch or the hands are wet. For example, it is very difficult to open a shampoo pouch with wet hands. A knife or a scissor is often required. However, knives or scissors may not be available every time. In their absence, the user may try to open the pouch by force. Many times, this force is disproportionate and the pouch gets ripped apart or the contents spill out. This led to the development of easy-tear pouches.
Easy-tear pouches are either made of special grade of plastics that tear easily, or they have a tear-notch or lines of weakness for ease of tearing.
Pouches having weakened tearing lines are known. Lasers are widely used to create the lines of weakness, but other means, such as mechanical weakening, are also known.
In the case of pouches which have lines of weakness, especially laser-scored lines of weakness, it is preferred that the tear-initiation and tear-propagation are easy. Tear-propagation should also ideally be towards a side of the pouch so that a portion (generally a corner) of the pouch may be torn-off easily. A drawback of some laser-scored pouches is that tear-initiation is difficult and tear-propagation is un-controlled. It sometimes propagates into the body of the pouch, rather than towards a side of the pouch.
An attempt was made to solve this problem in US5158499 A (American Can Company, 1992). This application discloses a plurality of linear or substantially straight continuous laser scored lines near or adjacent to a seal, and the lines extend across the entire width of the pouch. We have determined that linear tear-lines may not always provide controlled and guided tear-propagation. While opening the pouch along linear lines of weakness, the tear may propagate beyond the defined path and into the body of the pouch. We have also determined that linear laser-scored lines need to be weakened, e.g. laser-scored as in this application, to a significant depth. This requires higher laser power and consumes more electricity.
WO2009/110398 A1 (Hosokawa Yoko Co., Ltd.), which is regarded as the closest prior art, discloses a bag for easy discharge of large amounts of content at a time and with better gripping in use.
This application discloses a bag with a bag body having a first and a second side meeting each other and a third side extending obliquely to the first and the second side and defining an opening. A spout unit is coupled to the bag body and projects from the third side. The spout unit includes a zipper located inside of the bag body. The bag body may also include a tear portion coinciding with the oblique third side. The tear portion may be formed by thinning of the layers or it may be formed by a rough surface having an aggregation of fine holes. A U-shaped recessed portion is positioned away from the zipper and formed on at least one of the first and second sides for gripping the bag. This document does not disclose weakened lines for tearing of a portion of the bag.
US 2010/0226598 A1 (Stoeppelmann ) discloses pouches with three linear tear-lines for controlled and guided tear-propagation. The three weakened lines are spaced apart from one another. The middle line is much shorter than the other two lines. The middle line is provided with a tear-initiation notch. The other two lines extend across the width of the pouch. In use, the user may initiate tear at the middle line and when the user has torn the middle line completely, any excess force moves the tear line from that point, either to the first or to the second outer weakened line. On which of the two outer weakened lines the tear propagates after leaving the middle weakened line depends on the direction of the acting tearing forces. Thus, the middle line initiates the tear, while the outer weakened lines control and guide the tear propagation.
We have determined that in an automatic form fill seal machine, the packaging film experiences a significant amount of shift when the pouches are formed online. This shift does not always allow registration of the weakened lines on the front panel of the pouch with the corresponding weakened lines on the back panel. Furthermore, this shift does not always allow for alignment of the tear initiation notch with a pre-determined weakened line.
If the lines are not aligned, or if the tear initiation notch is not aligned with the weakened line, then the objective of easy tear may not be achieved. This problem may be solved by deeper weakening of the lines, but this may be at a cost. The mechanical strength of the pouches obtained by punching would fail under the stress exerted while running on the form fill seal machine.
Therefore, there is a need for pouches where the tear may be initiated easily and propagated with greater control and accuracy; even when there is some amount of shift of the film while forming and filling the pouches on FFS machines.
We have determined that this problem may be solved when a pouch has plurality of at least partly non-linear weakened lines and at least two of the weakened lines converge into a single line. The feature of plurality of partly non-linear weakened lines allows for ease of initiation and registration of the weakened lines on the front panel with the corresponding weakened lines on the back panel. The feature of at least two of the weakened lines converging into a single line allows for controlled and guided tear-propagation, so that a portion of the pouch may be removed easily.

SUMMARY OF THE INVENTION

According to a first aspect disclosed is a pouch with a continuous edge or plurality of edges, the pouch having plurality of weakened lines starting from the continuous edge or from one of the edges; wherein the plurality of weakened lines are at least partly non-linear and at least two lines converge to form a single weakened line.
According to a second aspect disclosed is use of a pouch of the first aspect for packaging home and personal care products, or food products.
The terms "line of weakness" and "score line" as used herein refer either to a complete cutting through of one or more layers of a film used for making the pouch, or to a weakening of such layer(s) allowing the layer(s) to be severed along the score line.

DETAILED DESCRIPTION

In one aspect disclosed is a pouch with a continuous edge or plurality of edges, the pouch having plurality of weakened lines starting from the continuous edge or from one of the edges; wherein the plurality of weakened lines are at least partly non-linear and at least two lines converge to form a single weakened line.
It is preferred that the single weakened line extends away from starting point of the plurality of weakened lines, towards the continuous edge, same edge, or a neighbouring edge.

The plurality of weakened lines

While the pouch may be torn easily when at least two of the plurality of weakened lines converge to form a single weakened line; it is preferred that all lines starting from the continuous edge or from one of the edges converge to form the single weakened line. This may further improve tear-initiation and especially tear-propagation, so that a portion (preferably some portion from an edge) of the pouch may be torn out with greater ease.
The single weakened line may extend towards the continuous edge, same edge, or a neighbouring edge. In this case, most of the pouch may be torn easily as the tear-propagation may be guided and controlled by the single weakened line.
Having torn a substantial portion of the pouch easily, the remaining portion may be torn by applying some force, or may also be left on the pouch if the opening is sufficient to access the contents easily. In case it is desired to tear-off the weakened portion completely and in order to further reduce efforts and to provide further easy tear-propagation with greater control on tear; it is preferred that the single weakened line extends to the continuous edge, same edge, or the neighbouring edge.
While the plurality of weakened lines are at least partly non-linear; it is preferred that each of the plurality of weakened lines is curved. This provides greater control on tear-propagation, when compared to other types of non-linear profiles. The radii of curvature of the lines when they are curved, depends on the size of the pouch/bag. Preferably, the radius of curvature of each of the curved lines is 10 mm to 150 mm.
The single weakened line may be linear, but it is preferred that it is curved. When curved, the radius of curvature of the single weakened line depends on the size of the pouch/bag. Preferably, the radius of curvature of the single weakened line is 10 mm to 150 mm.
Preferred pouches have at least three weakened lines. In such cases, it is further preferred that the second line is equidistant from the first and the third lines, until the lines converge.

Method of weakening

The weakened lines may be produced using methods including, but not limited to, scoring, perforating, chemical treatment, preferably laser scoring, laser perforation, mechanical scoring, mechanical perforation, embossing methods, or combinations of these methods.
The weakened lines are preferably made in the film before it is formed into a pouch, but alternatively, and less preferably, the lines of weakness may be introduced during or after pouch manufacture, by integrating a scoring means, e.g. laser-scoring means, with a form-fill-seal machine. In a preferred method, the material of the pouch is weakened at specific places.
This may be in registration with the artwork on the material, such that when the material is processed on form-fill-seal machines, the weakened lines are present at desired places. One skilled in the art of making pouches with lines of weakness for easy opening would know how to manipulate the positions of these weakened lines.
It is particularly preferred that each of the weakened lines is laser-scored, as such lines may be torn-off more easily and they provide greater control and accuracy on tear-initiation and tear-propagation
To use lasers, first a laser beam with sufficient wattage to evaporate a portion of a film is focused onto the film. The use of laser technology allows for accurate control of the depth or penetration from very slight scoring to complete perforation of the film. Laser wavelengths may range from about 0.2 to about 40 µm.
The laser beam may be used either in the single mode structure or the multimode structure. Further, the beams may be pulsed or continuous. Pulsed beams can be employed for forming dashed or discontinuous scores, but continuous beams are preferred when continuous easy open weakened lines are desired.
The output power of the laser can be of any wattage. High wattages are preferred for example when it is desired that the laser emits a plurality of beams. Thus, laser power can be in the range of up to about 500 watts in order to permit simultaneous use of e.g., five 100 Watt beams or ten 50 Watt beams.
Multiple beams can be produce by any of the known means such as beam splitting by partial reflectors. Generally, the beam power used may vary depending on the thickness of the multilayer structure or film or laminate being worked and the relative motion between the beam and the workplace. Any permutation combination of the beams may be used.
Blades may be used an alternative to lasers. The blades are installed on an engraving cylinder, which is mounted directly on the film processing machinery so that the cuts are made prior to formation of the pouch.
Different blade patterns can be used to get different patterns in the line of weakness. The pressure applied to the blades is also varied during the process to control the dimensions and depth of the cuts to ensure the bag opens easily.
Embossing is another alternative method for the line of weakness. Embossing technology weakens the film in specific areas by means of pressure, temperature, time and a deforming profile. The desired results are achieved by changing the calliper and/or material structure at the embossed trajectory. The basic equipment used for embossing consists of a sealing jaw capable of pressing against a back plate. A deforming profile or pattern is fixed to the jaw and heated. The film is pressed between the deforming profile and the back plate. The variables known to affect this process are heating temperature, cooling temperature, pressure, heating time, cooling time, film tension while embossing, film tension after embossing, back plate material, back plate thickness, back plate temperature, jaw pattern and jaw thickness.
The film may also be mechanically weakened by means of light punching, light-cutting or light-stamping.
The weakened lines may possess a pattern. Those patterns may take the form of a continuous line, a dashed line, or a combination thereof. However the most preferred pattern is the dashed line, wherein the dashed line is made of a plurality of scored segments. The length of each scored segment may vary from 0.12 mm to 4.4 mm, preferably from 0.3 mm to 2 mm, and most preferably from 0.6 mm to 1 mm. The distance between adjacent scored segments may vary from 0.4 mm to 4 mm, preferably from about 1 mm to 3 mm, and most from 1.5 mm to 2 mm. The score depth will vary depending upon the thickness of the film as well as the properties of the film, especially its strength. There may be a ratio of the length of scored segments to non-scored segments along each of the lines of weakness. This ratio preferably is from 1 to 2. In other words, a scored segment will be about one half the lengths of intermediate non-scored segments between each scored portion.
Most preferably, dotted laser-scored lines are made with minimum of 200 Watt laser power, controlling speed to 5 mm/s and at 60 µs pulse width.
While tear-initiation notches may be provided on one or more of the plurality of weakened lines; alternatively and more preferably, the continuous edge or one of the plurality of edges is serrated. Tear-initiation notches need to be punched out from formed pouches. Further, these notches need to be aligned precisely with the weakened lines. Precise alignment may not always be possible. Notches result in wastage of film material, and therefore, it is a lesser sustainable option. On the other hand, it is easier to have serrated edges. All that needs to be done for this is to have sealing-jaws with a blade shaped accordingly. In case of serrated edges, the problem of precise control is solved, because one of the serrations would generally coincide/be aligned with one of weakened lines. Preferably, the height of serrations is 4 to 10 mm, more preferably 5 mm to 8 mm and most preferably 5 mm.

The pouch

Pouches according to invention may be of any suitable shape or size. The pouches may be sized to package unit dose of shampoos or toothpastes, typically about 10 ml. Such packages are better known as sachets. The pouches may also be sized to package bulk quantities of products, such as five or ten kg detergent powders. When the pouch has a continuous edge, it may be circular, oval or ovoid in shape. In such cases, at least two of the plurality of weakened lines starting from the continuous edge converge to form a single weakened line extending at least some distance away from starting point of the plurality of weakened lines towards the continuous edge itself.
Height of preferred pouches is 60 mm to 650 mm; preferably 70 mm to 350 mm. Width of preferred pouches is 20 mm to 400 mm, preferably 150 mm to 200 mm. It is preferred that the height of top and bottom seals is 10 mm to 20 mm, more preferably 12 mm to 18 mm and most preferably about 15 mm.
On the other hand, when the pouch has plurality of edges, the pouch may be generally rectangular in shape. Such pouches may also be square, hexagonal, pyramidal, or of any polygonal shape. In the case of such pouches, the plurality of weakened lines may start from one edge and the single weakened line may extend at least some distance away from starting point of the plurality of weakened lines towards the same edge, or a neighbouring edge.
The pouch may preferably have linear edges, but alternatively, the one or more edges may be non-linear or contoured as described, for example in WO2010136282 A1 (Unilever NV ), or in WO0123271 A2 and EP1631507 A1 (both by Cryovac Inc, 2006). One skilled in the art of making FFS pouches would know how to vary their shapes.
The pouch may be a typical pillow-pouch, which has three seals; or a quad-pack, which has more seals. Quad-packs resemble a box and are more stable and sturdy. Pillow-pouches may be of any cross-section such as square, rectangular, circular or triangular. Skilled persons would understand these terms. The pouch may also be a 4-seal pack. Such packs are generally sold in curtain formats, as described, for example in WO06018140 A1 (Unilever NV ).
The pouch may also be a doy pouch. Doy pouches are stand-up pouches with a circular base and are generally used for packing liquid products.
A particularly preferred pouch has:

(i) a front panel joined to a back panel by a top seal and an opposed bottom seal, each defining a top and bottom edge of the pouch respectively; and,
(ii) at least one more seal which intersects said top and bottom seals,
wherein the plurality of weakened lines start from the top or bottom edge on each of the front and the back panel, and converge on each panel to form a single weakened line, which extends away from starting point of said plurality of weakened lines towards an edge between the top and bottom edges, and wherein at least one of the plurality of weakened lines on the front panel is aligned with at least one of the plurality of weakened lines on the back panel.

This alignment may provide easier tear-initiation and easier tear-propagation. In the case of non-gusseted 3-seal pouches (which are also known as pillow pouches), the process controls may allow greater accuracy in alignment of the plurality of weakened lines on the front and back panels, as in this case, the pouches are made of a single web (sheet) of film or laminate. However, in the case of 3-seal pouches with side gussets, there is always a possibility that the lines may not be aligned to each other because of the shift in the gussets, as the gussets are formed online, at very high speeds of pouch forming.
The lines may also not be aligned in the case of 4-seal pouches (which are generally referred to as sachets, and are used to pack unit dose shampoo and other cosmetics), because in these cases, the pouches are formed from two webs (sheets) of film or laminate which are sealed to each other at pre-determined points. Further, it is highly preferred that the single weakened line on the front panel is aligned with the single weakened line on the back panel.
In the case of 3-seal pouches, the third seal, preferably, is orthogonal to the top and the bottom seal.
Highly preferred pouches include opposed side gussets with inward folds sealed at the top and bottom seals, wherein the single weakened line on the front or back panel extends over one of the gussets and meets the single weakened line on the other panel. Such pouches are known as gusset-pouches.
Side gussets may also provide more area for graphics, similar to a carton. Further, side gussets allow expansion of the pouch and thus the pouch may accommodate more contents. In addition to, or instead of side-gussets, the pouch may have a bottom gusset. Such gusset allows the pouch to stand-up, and therefore such pouches are known as stand-up pouches.
While the single weakened line on one of the gussets may be non-linear; it is highly preferred that it is a straight line. A non-linear line, e.g. curved line, on the gusset is less preferred, because, without wishing to be bound by theory it is believed that, when the line is curved, it opposes tear propagation on the gusset. This happens because while the tearing force applied by the user is generally away from body of the pouch, the curved line resists this force and directs the tear into the body of the pouch.
On the other hand, it is believed that a straight (linear) weakened line on the gusset provides easier tear-propagation which is guided away from the body of the pouch. This allows for complete removal of a suitably sized portion of the pouch along with a portion of the gusset.
In a further preferred pouch, the plurality of weakened lines starts between the one more seal, i.e. the third seal, and the sealed inward folds. In such pouches, all the weakened lines originate on the top or bottom seal, and inwards of gusset ears (which are formed because of the inward gusset folds). On the other hand, if one or all the weakened lines originate on one of the gusset ears, then such a line may not be practically useful.

The film

Any suitable film structure may be used for making the pouches. The type of film chosen may be based on a number of parameters including, but not limited to the intended contents for the package such as moisture level and weight.
Other parameters may be intended storage and distribution conditions of the package and desired durability of the package.
The film structure may have one or more layers. Typically, the film is a two-layer or three-layer structure, but any number of layers suitable for the desired package may be used. The layers may be any suitable film material including, but not limited to, polymeric film materials and foil-type film materials. For example, the outer layer may be a polymeric film, such as oriented films including, but not limited to, PET (polyethylene terepthalate) and BON (bi-axially oriented nylon) or OPP (oriented polypropylene). The inner layer(s) may be any suitable inner layer such as, but not limited to, polyolefin-based or foil films. Generally, the layers are selected so that the laser, or other weakening means, is more effective on the outer layer and has less of an effect on the inner layer(s).
This allows the laser, or the other weakening means to efficiently score the substrate without any need to refocus the beam during the cross machine movement.
In multilayer films, structures or laminates, a tie or an adhesive may also be present between the layers. Suitable materials for such tie layers or adhesives are known to the skilled person and may include, by way of example, anhydride modified polyolefins, (e.g., graft copolymer of maleic anhydride and propylene wherein maleic anhydride moieties are grafted onto polypropylene chains) ethylene acrylic acid copolymers, ethylene methyl acrylate copolymers, blends or copolymers of PP and EVA, or other synthetic resinous materials. The selected adhesive should be stable under the conditions by which the pouches are prepared or used. Commercially available products for layers in preferred pouches include nylon 6 and 66. Preferred materials include ULTRAMID^® KR 4600 (BASF), NOVAMID^® 2030 (Mitsubishi Chem. Co.), DURATHANE^® (Farbenfabriken Bayer A.G.), "1030" (Unitika, Japan) SYTEL^® SUPERTUFF 811 (Du Pont), "4018" (Huels, Germany), and ELY^® 1256 (Elmser, Switzerland), MYLAR^®, DALAR^®, Exxon 5610A-2 (blend of PP containing EVA), ADMER^® (Mitsui, No. AT469C), BYNEL^® (Du Pont E361 or 3036), PLEZAR^® 3342, and SURLYN^®. ADMER^®, BYNEL^® and PLEXAR^® are believed to be maleic anhydride modified polyolefin.
Laminated films may also include a metallization layer or a metal foil layer between various layers of individual films.
Suitable laminated films may include any combination of low-density polyethylene, medium-density polyethylene, high-density polyethylene, linear low-density polyethylene, polypropylene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ionomer resins, ethylene-ethyl acrylate copolymers, ethylene-acrylate copolymers, ethylene-methacrylate copolymers, methyl pentene polymers, polybutene resins, polyvinyl chloride resins, polyvinyl acetate resins, polyvinylidene chloride resins, vinyl chloride-vinylidene chloride copolymers, polymethacrylate resins, polyacrylonitrile resins, polystyrene resins, acrylonitrile-styrene copolymers (AS resins), acrylonitrile-butadiene-styrene copolymers (ABS resins), polyester resins, polyamide resins, polycarbonate resins, polyvinyl alcohol resins, saponified ethylene-vinyl acetate copolymers. Fluorocarbon resins, diene resins, polyacetal resins, polyurethane resins, and nitrocellulose. Cellophane and synthetic paper sheets may also be used.
The film or laminate may be un-oriented, uni-axially oriented or bi-axially oriented. Thickness of the film or laminate is optional, and may be selected according to the desired end-use of the pouches. The films or laminates may be produced by an extrusion process, an inflation (i.e. blown) process or a coating process.
The package may be used under severe physical and chemical conditions; the component laminated films may be selected to meet severe requirements of packages, such as strength resisting deformation, drop-and-impact strength, pinhole resistance, heat resistance, sealing performance, quality maintenance performance, workability, and hygiene. Film Materials meeting these requirements may also be chosen.

Use

The pouch may be used for packaging home and personal care products, or food products. Apart from detergent powders, the pouches may be used to pack beverages such as citrus juices, e.g. orange juice, or concentrates thereof.
The package may also be used for tea, coffee and other granular material. The pouches may also be used to pack soap or detergent bars.
The invention will now be described in details with non-limiting exemplary embodiments. Reference should be made to the following detailed description of preferred embodiments.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 is the front view of a preferred embodiment of a pouch with side gussets.
Figure 2 is a back view of the embodiment of Figure 1.
Figure 3 is an isometric view of the embodiment of the pouch of Figure 1 from the front side.
Figure 4 is a magnified view of a demarcated portion of Figure-3.
Figure 5 is another isometric view of the embodiment of the pouch of Figure 1 from the front side.
Figure-6 is a plan view of the pouch of Figure-1 when seen in an opened-up manner.

DETAILED DESCRIPTION OF THE FIGURES

In the detailed description of the figures, like numerals have been used to represent like features.
Figure 1 is the front view of a preferred embodiment of a form-fill-seal pouch with three seals and side gussets. The pouch has a front panel (1) joined to a back panel (not seen in this view).
The pouch has a top seal (2) having a top serrated edge (3), and an opposed bottom seal (4) having a corresponding bottom serrated edge (5). The front panel (1) is joined to the back panel by the top seal (2) and the opposed bottom seal (4).
The distance between the top serrated edge (3) and the bottom serrated edge (5) defines the length of the pouch. The width of the pouch is defined by the distance between the edge (6) and the opposed edge (7). These dimensions may be varied depending on the amount of material intended to be packed in the pouch. On the top seal (2) and bottom seal (4) are the seal lines (represented by a common numeral (1a)). At these seal lines (1a), four layers of the film are sealed to each other because the opposed side gussets with inward folds are sealed at the top and bottom seals. The portion of the top serrated edge (3) between two seal lines (1 a) on the top seal (2) defines a common top edge of the front panel (1) and the back panel (not seen in this view) of the pouch. Similarly, the portion of the bottom serrated edge (5) between two seal lines (1a) on the bottom seal (4) defines a common bottom edge of the front panel (1) and the back panel of the pouch.
Near a corner of the pouch, three laser-scored non-linear curved lines (8, 9 and 10) start from the top serrated edge (3) on the front panel (1), and all lines converge on the front panel to form a single weakened line (11), which extends to the edge (6) between the top and bottom edges. The distance between the laser scored lines 8 and 10 (before they converge) is minimum permissible, as this may provide ease of tear -initiation and propagation. Serrations on the top serrated edge (3) provide points of initiation for tear, as one of the serrations will coincide with one of the weakened lines.
Figure 2 is the back view of the embodiment of Figure 1. As the pouch is a three seal pouch, it has a fin seal (13) which is orthogonal to the top seal (2) and the bottom seal (4). On the top seal (2) and bottom seal (4) are the seal lines (represented by a common numeral (12a)), which have been described in the description of Figure-1. Just like the front panel, the back panel (12) also has three laser-scored lines (14, 15 and 16) which start from the top serrated edge (3) and converge on the panel to form a single weakened line (17). The line (17) extends to the edge (18) between the top and bottom edges. The pouch also has another edge (19).
Laser-scored lines 8, 9, 10 and 11 on the front panel (1) are aligned with corresponding laser-scored lines 14, 15, 16 and 17 on the back panel (12).
Figure 3 is an isometric view of the embodiment of the pouch of Figure 1 from the front side. The pouch is filled with a detergent powder and it rests on the bottom seal. Therefore, the bottom seal is not visible in this view (and in Figures 4 and 5) Seen here is a pair of gusset ears (1 b) and (1 c) formed of front panel (1); and corresponding pair of gusset ears (12b) and (12c) formed of the back panel (12). The single laser scored line (11) extends over the edge (6) and over the gusset as a straight line (20).
Figure 4 is a magnified view of a demarcated portion of Figure-3.
Figure 5 is another isometric view of the embodiment of the pouch of Figure 1 from the front side, with the gusset ears opened up to show the linear (straight) laser scored line (20) on the gusset. Seen in this view is also a centre line of the gussets (21) which is just a fold line, and is not a weakened line.
To open the pouch the user may hold the front and the back panels of the pouch firmly between the fingers on either sides of the laser scored lines.
Force may then be applied to initiate the tear. When one of the curved lines tears apart, the tear is propagated easily because of the curved profile of the lines and a portion of the pouch can be torn apart to access the contents of the pouch. It should be understood that the specific forms of the invention herein illustrated and described are intended to be representative only as certain changes may be made therein without departing from the clear teachings of the disclosure.
Referring now to figure-6, which is a plan view of the pouch of Figure-1 when seen in an opened-up manner; the single laser-scored weakened line (11) on the front panel (1) extends as a linear weakened line (20) over a gusset and it meets the corresponding single laser-scored weakened line (17) on the back panel (12).
It will be appreciated that the illustrated examples provide for a pouch in which the tear may be initiated easily and propagated with greater control and accuracy; even when there is some amount of shift of the film while forming and filling the pouches on FFS machines.
Although the invention has been described with reference to specific embodiments, it will be appreciated by those skilled in the art that the invention may be embodied in many other forms without departing from the scope of the claims.

Claims

A pouch with a continuous edge or plurality of edges (3,5,6,7), said pouch comprising plurality of weakened lines (8,9,10) starting from the continuous edge or from one of the edges (3); characterised in that said plurality of weakened lines (8,9,10) are at least partly non-linear and at least two lines converge to form a single weakened line (11).
A pouch as claimed in claim 1 wherein said single weakened line (11) extends away from starting point of said plurality of weakened lines (8,9,10), towards said continuous edge, same edge, or a neighbouring edge (6).
A pouch as claimed in claim 1 or 2 wherein all lines starting from the continuous edge or from one of the edges (3,5,6,7), converge to form said single weakened line (11).
A pouch as claimed in any one of the preceding claims wherein said single weakened line (11) extends to said continuous edge, same edge, or said neighbouring edge.
A pouch as claimed in any one of the preceding claims wherein each of said plurality of weakened lines (8, 9,10) is curved.
A pouch as claimed in claim 5 wherein radius of curvature of each of said curved lines is 10 mm to 150 mm.
A pouch as claimed in any one of the preceding claims wherein said single weakened line (11) is curved.
A pouch as claimed in claim 7 wherein radius of curvature of said single weakened line (11) is 10 mm to 150 mm.
A pouch as claimed in any one of the preceding claims wherein said continuous edge or said one of the plurality of edges (3,5) is serrated.
A pouch as claimed in any one of the preceding claims comprising at least three weakened lines (8,9,10).
A pouch as claimed in any one of the preceding claims comprising:
(i) a front panel (1) joined to a back panel (12) by a top seal (2) and an opposed bottom seal (4), each defining a top (3) and bottom edge (5) of the pouch respectively; and,

(ii) at least one seal which intersects said top and bottom seals (13), wherein said plurality of weakened lines (8,9,10 or 14,15,16) start from said top (3) or bottom edge (5) on each of said front (1) and said back panel (12), and converge on each panel to form a single weakened line (11 or 17), which extends away from starting point of said plurality of weakened lines towards an edge (6,7) between said top (3) and bottom edges (5), and wherein at least one of the plurality of weakened lines (8,9,10) on the front panel (1) is aligned with at least one of the plurality of weakened lines (14,15,16) on the back panel (12).
A pouch as claimed in claim 11 wherein said single weakened line (11) on said front panel (1) is aligned with the single weakened line (17) on the back panel (12).
A pouch as claimed in claim 11 or 12 comprising opposed side gussets (1b, 1 c) with inward folds sealed at said top (2) and bottom seals (4), wherein said single weakened line (11) on said front or back panel extends over one of the gussets (1 b, 1 c) and meets the single weakened line (17) on the other panel.
A pouch as claimed in claim 13 wherein the single weakened line on said one of the gussets is a straight line (20).
A pouch as claimed in any one of the preceding claims wherein each of said weakened lines (8,9,10) is laser-scored.