EP0471211B1 - Easy opening flexible package containing Mozarella and packaging method - Google Patents

Description

The invention relates to a flexible bag type packaging with easy opening, as described in the preamble of claim 1.

Certain liquid or liquid-containing products, for example mozzarella, are sold in flexible and waterproof bags called "flow-packs".

This presentation has the advantage of being economical: it uses little packaging material and allows the continuous filling of the sachets during manufacture. In addition, it protects the environment because the plastic packaging material, for example polyethylene, can be destroyed without emitting pollutants. In addition, these sachets are practical, compact and their outer face can be printed to transmit a message or appear a brand.

Such packaging must be airtight, that is to say that it must resist the pressure of the liquid and that any leakage must be excluded, in particular for reasons of preservation of the products. This explains why they do not usually have a facilitated opening device, since current devices include pre-cuts or lines of weakness in the wall of the bag, incompatible with the sealing requirement.

Finally, the extraction of the products from the packaging, with a view to their consumption, requires cutting or drilling a sufficiently large opening, normally with a pair of scissors, to allow the liquid to flow and then take the product out. The liquid contained in the sachet inevitably spills during this operation by splashing the user.

There is known a packaging and a method of packaging a product in a sachet, in which the tear strip for easy opening is applied by heat sealing on the longitudinal edges of a film forming a tube and serves to seal the tube longitudinally. , described in US Pat. No. 3,373,926. This system requires the application of a line of anti-sealing material at the ends of the tear strip to allow the creation of grips. Such packaging is intended for the packaging of dry products such as snacks, but is not suitable for wrapping liquid products for which the sachet must be tight and the sealing zones resistant.

To achieve a tight seal, the tear strip should be wide and precisely adjusted along the longitudinal edges of the film. The longitudinal sealing zones along the strip would necessarily be narrow. Creating an anti-seal area at the side seal would require perfect adjustment and synchronization of the side seal and bag cutting elements, and the side seal area would be narrow at this point. All these factors would multiply the risk of leaks in the case of the packaging of a liquid product exerting a load constraint on the sealing zones during filling and handling of the sachets.

US-A-3098601 proposes as a solution to the problem of the easier opening of flexible polyethylene bags, the application of a tear strip by direct heat sealing on the external surface of the flexible bag perpendicular to the orientation of the constituent film of the wall of the bag.

This latter solution not having been entirely satisfactory, it has been proposed according to GB-A-1075989 to apply a heat-sensitive lacquer between the tear strip and the film of the sachet with a special point imprint allowing the initiation of the uprooting.

The invention proposes to solve the problem of continuous packaging in sachets of a liquid product or containing a liquid with easier opening without risk of leaks.

The invention therefore relates to a packaging of the flexible and liquid-tight sachet type formed by tubular wrapping by means of a mono- or bi-stretched film comprising a tear strip (10) heat-sealed outside the sachet for easier opening. , containing a liquid food product or a solid product immersed in a liquid, in particular Mozzarella (1) immersed in a preserving liquid (2) as described in the preamble of claim 1.

The packaging according to the invention is characterized in that the tear strip (10) is heat sealed on a part of the outer wall of the bag parallel to an orientation of the film at a location close to a longitudinal edge (11) from the sachet.

In a preferred embodiment of the packaging according to the invention, the tear strip is pre-incised transversely at one of its ends, for example over 3/4 of its width, so as to create a gripping tab as will be explained later. Preferably, the tear strip is made of the same material as the film of the bag and of greater thickness. It can consist of a laminated complex, the layer of which in contact with the sachet is made of the same material as the sachet.

Advantageously, the film of the sachet is mono-stretched which gives it an orientation in a direction. Because the tear strip is parallel to the orientation of the film, it can be torn along a straight line formed by the weld line between the film and the tear strip without the need for to create a line of weakness in its thickness. Preferably, the tear strip is heat sealed at a location near a longitudinal edge of the bag.

The choice of the material of the film is dictated by the requirements of the application.

Thus, the film can be made of a flexible waterproof plastic material oriented by stretching usable in the food industry, for example polyolefin such as low or medium density polyethylene. The advantage of polyolefin films is that they can be heat sealed to themselves without involving lacquer. These films can be surface treated so that they can be printed.

The tear strip can be made for example of polyester / polyethylene complex, the polyethylene layer being in contact with the film of the sachet, which allows the strip to be heat sealed on the sachet.

The invention also relates to a method for packaging a liquid food product or a solid product immersed in a liquid, in particular Mozzarella immersed in a preserving liquid in which a flexible mono- or bi- film is continuously formed. stretched into a tube by longitudinal sealing, the tube is filled with product, it is transversely sealed and the sachets are cut.

The method is characterized by the fact that an external tear strip by heat sealing is applied to the film before filling or to the tube during filling outside the longitudinal sealing zone parallel to an orientation of the film.

Preferably, the tear-off strip is applied over only part of the length of a sachet, so as to create gripping tabs enabling priming to be started. Advantageously, such a tab is created because the part of the strip which is not heat-sealed on the external face of the bag is pre-incised over part of its width, near its end close to the transverse weld line of the bag and can be easily released by traction to initiate the opening of the bag.

• la figure 1 illustre un sachet de mozzarella sous forme d'enveloppe selon l'invention,
• la figure 2 illustre une variante de l'emballage selon l'invention relative à un sachet à soufflet,
• les figures 3 à 5 illustrent les différentes phases d'ouverture du sachet,
• la figure 6 représente schématiquement un mode de réalisation du procédé d'emballage selon l'invention et
• la figure 7 représente schématiquement une variante du procédé d'emballage selon l'invention.

The invention will be better understood using the description of the embodiment below given by way of example with reference to the drawings in which:

• FIG. 1 illustrates a sachet of mozzarella in the form of an envelope according to the invention,
• FIG. 2 illustrates a variant of the packaging according to the invention relating to a bellows bag,
• FIGS. 3 to 5 illustrate the different phases of opening the bag,
• FIG. 6 schematically represents an embodiment of the packaging method according to the invention and
• FIG. 7 schematically represents a variant of the packaging method according to the invention.

In FIG. 1, mozzarella balls 1 and their preserving liquid 2 are contained in a flexible envelope 3 made of low or medium density polyethylene mono-drawn made from a section of tube 4. The section of tube 4 is closed by a lower transverse weld 5 and an upper transverse weld 6. A longitudinal weld 7 closes the tube 4 in the middle of the rear face 8 of the bag. On the front face 9 of the bag and on the outside is welded a tear strip 10 in the vicinity of the longitudinal edge 11.
The strip is made of low or medium density polyethylene with a thickness twice that of the envelope, pre-incised and welded over part 12 of its length and leaves an unwelded part free to facilitate the release of a grip tab 13 intended to initiate the uprooting. ' As shown, the strip is welded to the weld 5. Of course, the strip weld line could stop in the vicinity of the lower end of the bag provided that a sufficient opening is created to easily extract the mozzarella balls.

In Figure 2, the bag 14 has two longitudinal clips 15,16 on each side so as to form a bellows. The only difference with the envelope 3 is that the side welds take the folds and therefore consist of 4 layers at their ends.

As shown in Figures 3,4 and 5, to open the bag, it is rotated by 90 ° then we release the gripping tab 13 by tearing the pre-incision and grips the tear strip 10 by the tab 13 between the thumb and index finger and pull it for example to the right. The sachet then tears cleanly along the weld line parallel to the longitudinal upper edge of the sachet in the direction of stretching of the film. We can then empty the liquid and extract the product, for example the mozzarella balls through the slot thus provided without projection of liquid.

In FIG. 6, the packaging film 17 unwinding from the roll 18 will deploy on the conveyor line by means of a sailor neck shaper 19. The film 17 follows this neck which surrounds the top of a vertical metal tube 20. The neck causes the surrounding of the tube by the film. The film hose 21 thus formed is sealed by a heated flat iron 22 which will press the two selvedges 23 and 24 superimposed longitudinally of the film on the counterpart of the tube. At the outlet of the tube, the hose 21 released from the tube is pinched by two transverse irons 25 and 26 which ensure the transverse closure by welding. Simultaneously, the metered product is sent by gravity through the hopper 27 inside the tube 20 and falls on the lower transverse weld 5. The hose thus loaded descends, from the width provided for the sachet, by a drive system 28 pulling the bag down and it is welded by the two transverse bars 25 and 26. The width of the weld surface of the transverse bars can be separated by a cutting blade 29 making it possible to both close the d 'a sachet, the sealing of the bottom of the next sachet and the release of each individual sachet from the machine.

Before the film is formed into a hose, a reel 30 delivers the tear strip which is pre-cut at 31, then sealed by a weld jaw 32 over only part of its length. The end of the non-heat-sealed strip on the outside of the sachet is caught in the transverse weld of the sachet beyond the incision, which forms a loop. When opening, the gripping tab is easily released by simple traction by breaking the bridge of material remaining in the width of the strip after the incision.

In FIG. 7, the tear strip is unwound from the coil 30, pre-incised at 31 and applied by a soldering iron 33 to the hose 21 already formed.

The packaging process has been described for the envelope form of FIG. 1. Of course, the production of bellows sachets in accordance with FIG. 2 is similar except that it requires members performing the clamping of the hose after its formation.

Claims (8)

1. A pack of the flexible bag type impervious to liquids formed by tubular envelopment using a monoaxially or biaxially stretched film, comprising a tear strip (10) applied by heat-sealing to the outside of the bag for easy opening and containing a liquid food product or a solid product immersed in a liquid, more particularly mozzarella (1) immersed in a preserving liquid (2), characterized in that the tear strip (10) is applied by heat-sealing to a part of the outer wall of the bag parallel to an orientation of the film at a point near one longitudinal edge (11) of the bag.
2. A pack as claimed in claim 1, characterized in that the tear strip (10) is of the same material as the film (17) of the bag and of greater thickness.
3. A pack as claimed in claim 1, characterized in that the film (17) of the bag is monoaxially stretched.
4. A pack as claimed in claim 1, characterized in that the bag (14) comprises pleats (15,16) over its length and is in the form of a gusset.
5. A pack as claimed in claim 1, characterized in that the bag is in the form of an envelope (3).
6. A process for packaging a liquid food product or a solid product immersed in a liquid, more particularly mozzarella (1) immersed in a preserving liquid (2), in which a monoaxially or biaxially stretched flexible film (17) is continuously formed into a tube by longitudinal sealing, the tube is filled with product and transversely sealed, the bags are cut out and a tear strip (10) is applied to the outside of the bag by heat sealing, characterized in that a tear strip is applied to the film before filling or to the tube during filling by heat sealing outside the longitudinal sealing zone and parallel to an orientation of the film at a point near one longitudinal edge (11) of the bag.
7. A process as claimed in claim 6, characterized in that the tear strip (10) is applied to only part of the length of a bag, in that that end of the strip which is not heat sealed to the outer surface of the bag is included in the transverse welding (6) of the bag so that a loop is formed and in that the strip is pre-cut over part of its width in the vicinity of its end near the transverse weld line (6) of the bag.
8. A process as claimed in claim 7, characterized in that a tab (13) for starting the tear is released simply by pulling the loop.

Images