EP0861198B1 - Liquid-tight container and process for conditioning a liquid in said container - Google Patents

Abstract

This leaktight container includes four superimposed sheets (1, 2, 3, 4). The sheet (1) includes a precut tab (5) welded (13) to a portion of the sheet (2). A passage (10) is formed between these sheets (2) and (3) and acts as a valve between the inside and the outside of the leaktight container formed between the sheets (1, 4). A cut (9a) in the sheets (2, 3) allows the passage (10) to be placed in communication with the inside of the container formed between the sheets (1, 4). By pulling the tab (5) the wall of the passage (10) formed by the sheet (2) is torn and this passage is placed in communication with the outside.

Description

The present invention relates to a sealed enclosure equipped with a valve located inside of it and formed between two flexible sheets extending from an edge to a other of the enclosure and joined along two connecting lines non converging to delimit a conduit between them spacing of said flexible sheets from one another,

We know waterproof bags with a valve located inside the bag and formed between two sheets flexible, passing through part of the sachet, these sheets being joined together in two non-converging lines to form between they a channel by spacing of said sheets one of the other and being tightly fixed between the edges of the bag, except at the end of the canal adjacent to the edge of the bag. This channel allows the passage of a fluid between inside and outside of the bag, flexible sheets being intended to be pressed against each other as soon as we stop applying force to them to keep them away, thus preventing said fluid from leaving the bag.

We know such bags that have been described in the WO 95/23742, in FR 2 711 115 or in FR 1 338 549 especially.

The channel forming the valve of these sealed bags is normally open at both ends, so that it does not offer any guarantee to the consumer with regard to a use of this sachet prior to its purchase. Outraged that the purchaser therefore has no guarantee that the sachet still contains the volume of product initially packaged, he has no further guarantee as to the conditions hygiene of the product thus packaged.

We have already proposed in US-3 687 358 a system opening intended to access the interior of a sachet which includes, on the internal face of the wall of the bag a fragile layer fixed by its edge to this wall as well as its center. The part of the wall of the bag fixed to the fragile layer is welded to this fragile layer, so that by pulling the tab, we break the fragile layer and we open the bag.

It has been proposed in WO 95/23742 to close the end internal of the valve channel by an attached seal, requiring thus to add an element to the packaging. The closing the internal end of the canal guarantees hygiene of the product packaged in the sachet, but not that of the channel itself.

This type of waterproof enclosure with valve also poses another kind of problem. To function effectively, the channel forming the valve between the two flexible sheets must be of sufficient length to ensure waterproof closure. In the solutions proposed so far, in which the external opening of the valve is formed by a fold or a junction between one of the internal sheets and a wall of the bag, to increase the length of the channel we oriented it obliquely to the axis main bag, so the length of this conduit is greater than the depth at which the leaves flexible stretch in the bag. However that the size of the flexible sheets used is very significantly greater than the width of the channel, so that a significant amount of material is thus lost.

The inventors of the present invention have found the means of simultaneously solving the two problems, by forming a extending channel, like the leaves in which it is formed, from one edge to another of the enclosure waterproof, which allows the use of sheets whose width does not exceed much that of this channel.

Such a channel, if it allows optimal use the sheets extending through the sealed enclosure while reaching a sufficient length, does not communicate however neither with the interior nor with the exterior of the enclosure and at this stage forms a simple hermetically sealed space both inside and out the outside of the enclosure, unlike the oblique channel valves according to the state of the art.

A cut is made through at least one of the sheets in which the channel is formed, between the non-converging connecting lines delimiting this channel, the thus putting in communication with the outside. We are therefore finds with a channel communicating with the interior waterproof enclosure but inaccessible from the outside, giving thus all the inviolability guarantees sought.

To allow the consumer to access the interior of this channel by a simple and practical means, a tongue has been cut from the wall of the enclosure, a portion of this tab being fixed to the adjacent sheet used to form the channel, between the two connecting lines not converging at a location distant from the aforementioned cut. The end of this tab is left free to grab it. A tight connection is formed around the tongue, between the enclosure wall and the sheet adjacent. By pulling on the free end of the tab, we locally tear the sheet attached to it and we thus accesses, not directly inside the sealed enclosure, but inside the valve channel, so that we can introduce a straw which will allow to separate the two walls of the channel and to draw the liquid of the enclosure.

In addition to optimal use of the material in sheet forming the valve, one of the objects of the present invention is an optimal use of the volume of the sachet. In state-of-the-art bags, we leave the upper part of the open bag to allow filling. The filling level cannot be very high in this case, otherwise the liquid overflows from the bag when welding the upper edge. As a result, the filling rate of the sachet by the liquid is not very high. We certainly have the possibility of filling the sachet through the channel of the valve, but liquid will remain in this channel which is not not acceptable, the channel must remain perfectly clean until its first use.

Advantageously, a second channel is formed between said flexible sheets in which the channel of the valve, this second channel having an external end adjacent to an edge of said enclosure and the other end in communication with the interior of this enclosure

This invention also relates to a method of packaging of a liquid in a sachet or an enclosure comprising said second channel, according to which the bag is formed as well as the two channels, we leave at least open the outer end of said second channel adjacent to the edge of said sachet, said liquid is introduced through this second channel and closing said outer end of the second channel.

This invention finally relates to a use of said sealed enclosure according to claim 15.

Among the many advantages of the enclosure present invention, the proposed solution does not add any additional element to the sealed enclosure compared to known solutions, the tongue being formed by a portion of the enclosure wall. This solution therefore does not no increase in production costs. In addition, existing production lines can continue to be used with very slight modifications for a advantage that is not negligible in terms of product.

The enclosure is protected against any attempt to violation. Hygiene conditions are perfectly guaranteed until the first use of the sachet. The elements forming the bag and the valve are minimized, no added element is not necessary to ensure inviolability valve. The sheet area required for realize the duct and the filling volume of the bag are optimized.

La figure 1 est une vue en élévation illustrant les différentes étapes du processus de fabrication de cette enceinte étanche.

La figure 2 est une vue en plan selon la ligne II-II de la figure 1.

La figure 3 est une vue en plan selon la ligne III-III de la figure 1.

La figure 4 est une vue en plan selon la ligne IV-IV de la figure 1.

La figure 5 est une vue en plan selon la ligne V-V de la figure 1.

La figure 6 est une vue en plan selon la ligne VI-VI de la figure 1.

La figure 7 est une vue en plan selon la ligne VII-VII de la figure 1.

La figure 8 est une vue en coupe selon la ligne VIII-VIII de la figure 7.

La figure 9 est une vue en coupe selon la ligne IX-IX de la figure 7.

Les figures 10, 11 et 12 sont des vues en perspective d'un sachet étanche, illustrant trois stades de son utilisation.

Les figures 13 a 15 sont des vues en perspective d'une variante, illustrant trois stades de son utilisation.

Les figures 16 à 19 illustrent différentes phases de réalisation d'une variante de l'enceinte objet de l'invention.

La figure 20 est une vue partielle en élévation d'une variante du processus de fabrication de la figure 1.

La figure 21 est une vue en coupe illustrant les étapes successives du processus de fabrication de la figure 20, selon les lignes a-a, b-b, c-c, d-d, e-e et f-f.

Other advantages will appear on reading the following description made with the aid of the appended drawing which illustrates, schematically and by way of example, an embodiment and various variants of the sealed enclosure, object of this invention .

Figure 1 is an elevational view illustrating the different stages of the manufacturing process of this sealed enclosure.

Figure 2 is a plan view along line II-II of Figure 1.

Figure 3 is a plan view along line III-III of Figure 1.

Figure 4 is a plan view along line IV-IV of Figure 1.

FIG. 5 is a plan view along the line VV in FIG. 1.

Figure 6 is a plan view along line VI-VI of Figure 1.

Figure 7 is a plan view along the line VII-VII of Figure 1.

FIG. 8 is a sectional view along line VIII-VIII of FIG. 7.

FIG. 9 is a sectional view along the line IX-IX in FIG. 7.

Figures 10, 11 and 12 are perspective views of a sealed bag, illustrating three stages of its use.

Figures 13 to 15 are perspective views of a variant, illustrating three stages of its use.

Figures 16 to 19 illustrate different phases of production of a variant of the enclosure object of the invention.

FIG. 20 is a partial view in elevation of a variant of the manufacturing process of FIG. 1.

Figure 21 is a sectional view illustrating the successive stages of the manufacturing process of Figure 20, along the lines aa, bb, cc, dd, ee and ff.

Figure 1 illustrates four strips 1, 2, 3, 4 of film monolayer or multilayer thermoplastic such as polystyrene, polypropylene, polyethylene or polyamide, endless, used for the manufacture of the waterproof bag, object of the invention. Bands 1 and 4, wider, are intended to form the walls of the sachet, while the narrow strips 2 and 3 are used to make the valve. Preferably, the film thickness of strips 2 and 3 of the order of 40 µm is less than that of the film in bands 1 and 4 of around 100 µm, to make bands 2 and 3 more flexible to facilitate closing the valve.

The different manufacturing operations for this sachet take place online on strips 1 to 4 and are illustrated by Figures 2 to 7 where the width of the bag is drawn in dashed lines.

The first operation is performed on sheet 1 and consists in pre-cutting tabs 5 at regular intervals. Each tab 5 is intended to be located in the vicinity from one of the corners of the bag. The end of this tongue 5 is cut while its parallel edges are pre-cut so that before use, the tongue 5 remains in the plane of sheet 1.

The second operation (fig. 3) consists in depositing a rectangle of ink or heat-resistant varnish 6 on the sheet 2, at regular intervals, corresponding to the intervals between the tabs 5.

The third operation is to weld the sheets 2 and 3 along two parallel lines 7 and 8 (fig. 4) fitting out a channel 10 between them, the flexible walls of which are normally contiguous, but are likely to be discarded one from the other, thus constituting the valve controlling the distribution of the conditioned liquid. These welds 7 and 8 get thinner where the heat-resistant varnish is 6. During the same operation, two parallel cuts 9 are provided in the welds 7 and 8 and a cutout transverse 9a connects the parallel cutouts 9, putting thus channel 10 in communication with the outside.

During the fourth operation (fig. 5), we weld the two strips 2 and 3 on the strip 1 according to a weld 11 which extends along the outer edge of bands 2 and 3 and at near the adjacent edge of strip 1. We also realize a weld 12 which surrounds the long sides of the rectangle heat-resistant varnish 6 deposited on sheet 2 and which cut this rectangle 6 across its width, so as not to weld sheets 2 and 3 together at the location of the channel 10. Welding 13 is also carried out, in the form of a rectangle, superimposed on the rectangle of heat-resistant varnish 6, so that only sheets 1 and 2 are welded together at the place of this rectangle 13.

Then, in the next step, we cover the strips 1, 2, 3 of the fourth strip 4 and three welds are made 14a, 14b, 14c, forming three sides of the sealed bag 15, one 14b along one of the edges of bands 1 and 4 and the two others 14a, 14c transversely to these bands. The fourth side, adjacent to the other edge of strips 1 and 4 remains open to allow subsequent filling of the waterproof bag 15.

The last step is to separate the sachets sealed from each other between two welds 14a, 14c adjacent.

The waterproof bag 15 illustrated in FIG. 7 is ready to receive the liquid to be conditioned, after which the fourth side will be welded, enclosing the liquid so waterproof.

The contents of such a sachet cannot be consumed at from the hermetically sealed bag, after filling made from the bag illustrated in Figure 7. In indeed, no opening then allows access to the interior of the waterproof bag, so that the inviolability of this sachet is guaranteed and verifiable and the preservation of conditions hygienic packaging is ensured in the since no opening allows access to the interior from the sachet.

Figures 10 to 12 show how it is possible to access the contents of the sachet using a straw or any duct 17 allowing to make pass the liquid from the inside to the outside. It is enough detach the tab 5 and pull it towards the edge 14c of the bag 15. Since the tongue 5 is welded according to the welding rectangle 13 to the strip 2 constituting one of the walls of channel 10, by pulling it, we causes a tear in this wall 2, thus sparing a opening 16 of channel 10. This opening 16 allows the introduction of a tubular element 17 such as a straw or a pouring element. The length of this tubular element 17 must be sufficient to come out of the cut end 9a channel 10, thus bringing the contents of the sealed bag into communication with the outside.

To interrupt this communication before exhaustion liquid contained in the sachet, simply remove the straw 17 so that its end is set back from a certain distance from the cut end 9a of the channel 10. Preferably, as illustrated by FIGS. 7 and 12, the start of channel 10 has a sudden widening 10a intended to allow to accommodate and maintain one end folded 17a of straw 17 when you want to interrupt fluid consumption. The background of enlargement 10a also forms a stop for the end 17a of the straw 17 preventing this straw from sinking into the channel 10 to a depth where it would open the valve that forms this channel 10. As can be seen in FIGS. 10 to 12, the edge of the tongue 5 adjoining the wall 1 of the bag watertight 15 is adjacent to the weld 14c, so that this welding limits the tear-off length of the tongue 5.

The variant illustrated in Figures 13 to 15 consists to be added to the part of the bag 15 fitted with the valve, a strip of a more rigid material, such as a strip of thicker material (on the order of 200-250 µm) 18, such as thermoplastic film of the same kind as that of the sheets 1 to 4. This strip 18 is provided with parallel folding grooves 19 which are obtained by compression. This strip 18 is attached to the bag by welding it to the tongue 5, itself welded according to rectangle 13 to sheet 2, as illustrated by Figures 5 to 7.

By pulling on the strip 18, we pull the tab 5 and we tears the wall of channel 10, thus opening the valve. We detach then the strip 18 of the tongue 5, the weld between this strip 18 and this tab being chosen to offer lower tensile strength than welding 13 between tab 5 and sheet 2. Once the strip 18 is detached, it is folded according to the folding grooves 19 to form a conduit playing either the role of straw or that of the spout according to the given shape and we introduce it in opening 16 as before (Figure 15).

The variant illustrated by FIGS. 16 to 19 presents, in addition to channel 10 serving as a valve and distribution conduit liquid packaged in the bag, channel 20 intended only for filling the sachet.

The bag manufacturing operations according to this variant are the same as those described for the embodiment previous so that we will describe these operations of more succinctly for this variant.

As before, we perform a precut of the opening tab 5 in sheet 1 used to form one of the walls of the bag. At the same time, a layer is deposited of varnish savings 6 on one 2 of the sheets, intended for form the valve. As seen in Figures 16-19, the layer of savings varnish 6 also extends over a portion 6a of the width of the weld 14a forming the periphery of the bag, and over a certain length of this seal 14a, for the purpose which will be explained later.

Then we proceed to the welding of sheets 2 and 3 along lines 7, 8 to form channel 10 and to cut 9 to put this channel in communication with the interior from the sachet. As for channel 20, it is formed between the weld 8 and a weld 21 which extends along the inner edge sheets 2 and 3.

Once the channels 10 and 20 have been formed, the sheets 2 and 3 to sheet 1 using a weld 22 (Fig. 17) which has an opening 22a superimposed on the head 5a of the tongue 5. This weld, as before, assemble the rest of the tongue 5 to the wall 1 of the sachet, varnish spares 6 preventing the welding of the two walls 2 and 3 at the location of channel 10 between them.

We superimpose at this stage (fig. 18), sheet 4 to sheets 1, 2 and 3 and welded them edge to edge to form the waterproof bag. During this operation, we make sure to superimpose the welding of the edge of the bag on zone 6a coated with savings varnish, which leaves open this part of the bag.

The following operation consists in introducing into the channel 10 a folded straw 17 and in the channel 20 a cannula filling 23. Once filling is complete, close the ends of channels 10 and 20 by welding the edge of the bag in the part of the width left free by the varnish savings 6a as illustrated in FIG. 19.

This bag can then be used as the described bag previously, by tearing off the tab 5 giving access at straw 17 and at distribution channel 10.

Of course, we can also not put straw in channel 10, in which case its outer end can be closed when welding the edge of the bag and do not leave open that the end of the second channel 20 adjacent to this edge.

Although the essential advantage of the present invention either linked to waterproof enclosures with flexible walls of the bag type, the invention could also be applied to other types of sealed enclosures for the packaging of liquid. Of course, the invention is in no way limited to causes the membrane attached to the inside of the wall of the enclosure is constituted by a through strip the length or width of the enclosure, the use of a tape of this type is advantageous because it allows make the enclosure according to the invention continuously from strip materials. The entire surface of strip 34 must not not necessarily be welded to the inside of the wall 1 of the sachet. It suffices to weld it to the body 5b of the tongue, and isolate the unwelded portion of the membrane 34, adjacent to the gripping end 5a of the tongue 5, from the inside of the bag by a tight connection, to prevent the liquid from escaping, as long as the part of the membrane 34 welded to the body 5b of the tongue 5 has not been torn.

Figures 20 and 21 illustrate not only a variant of the process of FIGS. 1 to 7, but also a variant of the valve formed between the sheets 2 and 3 arranged between sheets 1 and 4 forming the sachet. In this variant, sheet 1 has not been shown, but it obviously exists.

The first operation performed in Figure 20 is illustrated by section a-a in figure 21 and corresponds to welding 7 ', 8' delimiting the channel 10 'of the valve. As we can see, this channel is not with parallel edges and the purposes and functions of the variations will be explained below section thus given to channel 10. A weld transverse 42 is formed near one end of the channel 10 ', the usefulness of this weld will be explained by the after.

The following operation consists in cutting 9 ′, 9 'intended to make this channel 10' communicate with the outside. This cutout 9 'has the shape of a U, the two of which branches are not the same length. As one can see, this asymmetry of the branches of the U-shaped cut 9 'coincides with the asymmetry of the narrowing in the middle from the 10 'channel. This asymmetry of the 10 'channel and the cut 9 'has shown that it improves the closure of the valve, that is to say of the part of the channel 10 'extending from the asymmetrical narrowing of this channel and the cut 9 ', 9'a.

During the operation illustrated by the following section c-c, a straw 17 'is introduced into the channel 10'. The diameter of this straw is such that it corresponds substantially the narrowing formed at the entrance to the channel 10 '. From this made a seal is obtained between the straw and the end inlet of the 10 'channel, so that the liquid which may have flow between channel 10 'and straw 17' during opening of the valve is prevented from leaving this channel 10 '. We can also note that the end of the straw 17 'introduced in the channel 10 'has a bulge 17'a which serves to prevent straw 17 'from coming out of channel 10', this bulge coming up against the narrowing at the entrance from the 10 'channel. Furthermore, the transverse weld 42 limits the displacement of the straw 17 'in the conduit 10'.

The operation illustrated by section d-d is carried out in parallel on the sheet 4 forming one of the walls of the bag. It consists of cutting the tongue 5.

Between the 17 'straw insertion operation (c-c) and the following operation d-d, the sheet 4 joins the two other sheets 2,3 and one non-weldable sheet (not shown is interposed between the straw and the adjacent sheet 3 sheet 4. As a result, the welding 40 carried out at the e-e operation only welds sheets 3 and 4 together the opening 40a serves to leave free the end 5a of the tongue 5, the rest of this tongue being welded to the sheet 4.

The last operation consists in carrying out two points welds 41 between the welds 7 ', 8' forming the channel 10 ' and the wall 4 of the bag as well as two parallel weld lines 43, the spacing of which corresponds to that of the welds 7 ', 8' from channel 10 '. These welds 43 connect the valve formed by the channel 10 'at the opposite edge of the sheets 2, 3 and 4. They thus delimit the width of the receiving accommodation the folded part of the straw 17 '. As for the welding points 41, they are used to prevent leaves 2, 3 from following the straw 17 'when the bulge 17'a is brought into abutment against the narrowing located at the entrance of the channel 10 ', allowing the valve to close.

Claims (15)

1. Leaktight container fitted with a valve which lies inside this container and is formed between two flexible sheets (2, 3) extending from one edge of the container to the other and joined together along two non-converging connection lines (7, 8) so that when the said flexible sheets (2, 3) are parted, a passge (10) is delimited between them, characterized in that the two non-converging connection lines (7, 8) extend from one edge of the container to the other, a portion of one (2) of the said sheets, which lies between the two non-converging connection lines (7, 8) being fixed to a tab (5) cut in the adjacent wall (1) of the container and attached to this wall by one end, whereas the other end is free so as to form a means from grasping, a leaktight connection between the sheet (2) and the adjacent wall (1) of the container extending right around the periphery of the said tab (5), this tab being used to break the portion of the said sheet (2) which is fixed to it, by pulling on its free end, in order to place the said passage (10) in communication with the outside, a cut (9a) being made through at least one of the said sheets (2, 3) between the said non-converging connection lines (7, 8), this cut being distant from that portion of the sheet (5) which is fixed to the tab (5) and serving to place the said passage in communication with the inside of the said container.
2. Leaktight container according to Claim 1, characterized in that the part of the said tab (5) attached to the wall (1) of the container is adjacent to a weld (14c, 33) joining together two walls (1, 4; 1, 34) of this container.
3. Leaktight container according to Claim 1, characterized in that the passage (10) formed by the said connection lines (7, 8) has a widened part adjacent to the end of the passage, a wall portion of which is integral with the said tab (5).
4. Leaktight container according to Claim 1, characterized in that a strip (18) of a material which is more rigid than the walls (1, 4) of the container is attached thereto and rendered integral with the outer face of the said tab (5) to allow the said passage (10) to be opened when this strip (18) is detached from the said container.
5. Leaktight container according to Claim 4, characterized in that the said strip (18) of material has score lines (19) arranged so that after folding it forms a pipe which can be inserted into the said passage (10) to open the valve and allow the liquid contained in the said container to pass through.
6. Leaktight container according to Claim 1, characterized in that the said non-converging connection lines (7, 8) extend parallel to one edge of the bag, joining together two opposite edges (14a, 14c).
7. Leaktight container according to Claim 1, characterized in that a second passage (20) is formed between the said flexible sheets (2, 3) and has an outer end adjacent to one edge of the said container and the other end in communication with the inside of this container.
8. Container according to Claim 7, characterized in that two of the respective ends of the said passages (10, 20) coincide with one edge of the said container and are adjacent to one another.
9. Leaktight container according to Claim 3, characterized in that the cross-section of the said passage (10') close to its opposite end to the said cut (9'a) has a narrowing, the cross-section of which corresponds substantially to that of the said dispensing pipe (17').
10. Leaktight container according to Claim 9, characterized in that the said narrowing of the cross-section of the said passage (10') additionally constitutes a stop intended to interact with a corresponding stop (17'a) integral with the dispensing pipe (17').
11. Leaktight container according to Claim 1, characterized in that the said two flexible sheets (2, 3) joined together along two non-converging lines (7, 8) are attached to one of the walls (1, 4) of this containers [sic] at least at two points (41) located one on each side of the said passage (10, 10').
12. Method for packaging a liquid in the container according to Claim 7, characterized in that the container together with the two passages (10, 20) is formed, at least the outer end of the said second passage (20) adjacent to the edge of the said container is left open, the said liquid is introduced through this second passage (20) and the said outer end of the second passage (20) is sealed.
13. Method according to Claim 12, characterized in that when forming the said container, a layer of sparing lacquer (6a) is deposited between the edge of the said flexible sheets (2, 3) corresponding at least to the outer opening of the said second passage (20) adjacent to the edge of the said container, the width of this layer (6a) being less than that of the weld (14a) forming the edge of the container, the edge of the container is welded up, reducing the width of this weld at the point corresponding to the opening of the second passage (20) adjacent to the edge of the container to that of the said layer of sparing lacquer (6a) and superimposing this reduced-width weld therewith, the container is filled through this second passage (20) and a lateral weld adjacent to the said layer of sparing lacquer (6a) is formed between the two edges of the narrowing on the part of the width of the weld (14a) of the edge of the container left free by the layer of sparing lacquer (6a) at the location of the outer opening of the said second passage (20).
14. Method according to one of Claims 12 and 13, characterized in that when forming the said container, a layer of sparing lacquer (6a) is deposited between the edge of the said flexible sheets (2, 3) corresponding to the other end of the said first passage (10) coinciding with one edge of the said container, away from the end where the said flexible sheets (2, 3) are cut (9) between the said non-converging lines (7, 8), the width of this layer (6a) being less than that of the weld (14a) forming the edge of the container, the edge of the containeer is welded up, reducing the width of this weld at the point corresponding to the said other end of the said first passage (10), to that of the said layer (6a) of sparing lacquer and superimposing this reduced-width weld therewith, and a lateral weld is formed adjacent to the said layer of sparing lacquer (6a).
15. Use of the said leaktight container according to one of Claims 3 and 7, for packaging a liquid, characterized in that a removable pipe (17) for dispensing the liquid packaged in the said container is introduced into the said passage (10), that part of this removable pipe which lies outside this passage being bent over, the end of this bent-over part (17a) being brought into abutment against the bottom of the said widened part of the said passage (10) in order to prevent this dispensing pipe (17) from penetrating the said passage beyond a determined length.

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