EP0746507A1

EP0746507A1 - Sealed envelope, method for the manufacture thereof, and method for filling said envelope with a beverage

Info

Publication number: EP0746507A1
Application number: EP95909081A
Authority: EP
Inventors: Alain Delsahut
Original assignee: BRAINTRUST Ltd; Carapak Braintrust NV
Current assignee: Carapak Braintrust NV
Priority date: 1994-03-03
Filing date: 1995-03-03
Publication date: 1996-12-11
Anticipated expiration: 2015-03-03
Also published as: US20020015541A1; EP0746507B1; WO1995023742A1; US6481889B2; DE69505106T2; ES2125006T3; DE69505106D1; AU1716795A

Abstract

The sealed envelope includes a valve (43, 44) closed by a disk (42) which can be perforated. Said valve (43, 44) is made by folding and welding a peripheral strip from one of the walls. The second wall or rear wall of the envelope is sealed along its lateral edges (50, 51) and includes a bulge portion (49) along the base (52, 53). The outer face of the bulge portion is made of a laminated, non-weldable material. The upper edge (55) is only welded after said container is filled with a beverage.

Description

WATERPROOF ENCLOSURE, METHOD FOR MANUFACTURING THE ENCLOSURE, AND METHOD FOR CONDITIONING A BEVERAGE IN THE ENCLOSURE

The present invention relates to a sealed enclosure provided with a valve, at least part of which extends inside the enclosure and is formed between two flexible sheets joined in two non-converging lines to form a conduit between them. spacing of said flexible sheets from one another, allowing the passage of a fluid between the inside and the outside of the enclosure, these sheets being intended to be pressed against each other as soon as the it ceases to apply a force to them apart, thus preventing said fluid from leaving the enclosure. This invention also relates to a method for manufacturing this enclosure, as well as to a method for packaging a drink.

We have already proposed such sealed enclosures provided with a valve made in an extension of the wall of the enclosure itself, thus avoiding the problems associated with the attachment of an attached valve. Such enclosures are described in particular in GB 826.784 as well as in FR 1 338 549. The last of these documents proposes to produce this enclosure from a tubular element. The disadvantage of this solution is that it requires the tubular element to be turned over in order to place the valve inside the enclosure. Such a solution does not lend itself to manufacturing on an automatic production line generally comprising bending, welding and cutting stations.

As for GB 826,784 its main drawback lies in the fact that it only allows the filling of the enclosure in the event that it is called upon to serve for the packaging of a drink, only through the orifice of the valve whose cross section is necessarily very small since it is provided, by definition, to allow the passage of a straw. Therefore, the filling speed of the enclosure is necessarily reduced by the section of the passage, limiting the speed of the production line. Such a solution is obviously not economically profitable. Another drawback is that this solution is not suitable for being produced on known types of machines, available or adaptable to the manufacture of the enclosure.

The object of the present invention is to remedy, at least in part, the drawbacks of the above-mentioned solutions.

To this end, the subject of this invention is a sealed enclosure of the aforementioned type, as defined by claim 1.

It also relates to a method for packaging a drink in this sealed enclosure, as defined by claim 1.

Finally, it relates to a method of manufacturing the sealed enclosure as defined by claim 22.

The advantage of the proposed solution is to allow the manufacture of the sealed enclosure with valve integrated into a single wall of the enclosure which allows the use of existing type production lines starting from flat plastic film. When the enclosure is intended for the packaging of beverages, this enclosure can be filled at a high flow rate, through an orifice with a section much larger than that of the valve.

The accompanying drawing illustrates, schematically and by way of example, different embodiments and variants of the sealed enclosure, as well as their methods of manufacture, according to the present invention.

Figures 1 to 4 are perspective views illustrating the different stages of the production of an enclosure according to one embodiment.

Figure 5 is a sectional view along line XV-XV of Figure 4.

Figures 6 to 12 are perspective views illustrating the various stages of manufacture and filling of the first embodiment.

Figures 13 to 17 are perspective views illustrating the different stages of manufacture and filling of the second embodiment.

Figures 18 and 19 are perspective views of two variants of Figure 12. Figures 20 to 20f are partial views of an alternative embodiment of the embodiments of Figures 1 and 2 or 7 and 9.

Figures 21a to 21d are partial views of another alternative embodiment.

Figure 22 is a sectional view of yet another variant.

FIG. 23 is a perspective view of another variant of the embodiment illustrated in FIG. 18.

FIG. 24 is a plan view of a variant of the valve applicable to any of the embodiments linked to an enclosure for packaging a liquid.

Figure 25 is a perspective view of a method of manufacturing a variant of the sealed enclosure object of one invention.

Figure 26 is a sectional view along line XXVI-XXVI of Figure 25 of this variant.

Figure 27 is a perspective view of another variant of the method of manufacturing a variant of the sealed enclosure.

FIG. 28 is a sectional view along the line XXVIII-XXVIII of FIG. 27.

FIG. 29 is a perspective view of a last variant of the method of manufacturing another variant of the sealed enclosure.

Figure 30 is a sectional view along line XXX-XXX of Figure 29.

FIG. 31 is a perspective view of a variant of FIGS. 4 and 5.

Figure 32 is a sectional view of a last variant of the sealed enclosure.

As shown in FIG. 1, we start from a sheet 24 which is folded a first time to form the strip 24a, we weld, preferably simultaneously, welds 28 and 29 'as well as two parallel oblique welds 30 and 31 extending from one to the other weld 28 and 29 'to form the valve. For this purpose, the welds 28 and 29 ′ stop between the welds 30 and 31 and, then, a cutout 32 is provided. in the first fold between these welds 30 and 31 to form a through passage between them. The weld 28 stops at a certain distance from the free edge of the strip 24a.

The sheet 24 is folded again in the vicinity of the weld 28 (in the direction of the arrow F - Figure 1) to form a strip 24b and the weld 29 'is fixed to the sheet 24 by a new weld 29 (Figure 2 ) thus now connecting three thicknesses of the sheet 24 together. Like the initial weld 29 ′, this new weld 29 stops between the oblique welds 30, 31 of the valve.

On the sheet 24, the sheet 25 is then placed (FIG. 3) and these sheets are welded together to form a pocket between them, on the one hand, and the welds 33, on the other hand, to receive an object to be packaged. Preferably, the side edges of this pocket, closed by the welds 33, widen to facilitate positioning of the object in the pocket. The sheets 24 and 25 therefore form the internal walls of the sealed enclosure. Two more openings 34 are provided, the role of which will be explained later.

The two sheets 26, 27 are then placed respectively on the sheet 24 and on the sheet 25 (FIG. 4). A weld 35 is formed between an edge of the sheet 26 and the adjacent edge of the strip 24a. A weld 36 is formed between the two adjacent edges of the sheets 25 and 27 and another weld 37 is formed parallel to the previous ones between the adjacent edges of the four sheets 24, 25, 26 and 27 (Figure 5). Finally, two other parallel welds are formed, of which only one, 38, is visible in FIG. 4, along the other two edges of the sheets 24 to 27, thus completing the packaging. Since the four sheets 24 to 27 are welded together on three sides and two by two on the fourth side and the valve opens between the sheets 24 and 26, if the sheets 24 and 25 were not pierced with the openings 34, only the space between the sheets 24 and 26 could be inflated. These openings 34 therefore serve to place the space between the sheets 25 and 27 in communication with the valve formed between the strips 24a, 24b of the sheet 24.

Alternatively, the enclosure, instead of providing a watertight pocket between two double walls, could be single-walled, that is to say that it would only have the sheets 24 and 26 and that the sheet 24 would not be pierced by the openings 34. Such an enclosure could serve when packaging a liquid, for example a drink.

Thanks to the design of the packaging illustrated in FIGS. 1 to 4, the external walls 26, 27 can be made of materials different from those of the sheets 24, 25. This is how these external walls 26, 27 could be, for example, thicker. One could also imagine that these external walls are rigid or semi-rigid shells.

In the examples cited, the walls of the enclosure are weldable, in particular by ultrasound, and are based on polyethylene (PE) or linear low density polyethylene (LLDPE), preferably made of PE / X / laminates. PE, X being constituted by an airtight barrier such as polyethylene vinyl alcohol (EVOH), polyamide (PA) or bioriented polyamide (OPA). Of course, welding could also be replaced by bonding, although it is more complicated to implement. The PE / X / PE constitution allows welding on both sides of the sheet.

It can also be noted that the welding lines 28 and 29 connecting the welding line 29 'to the sheet 24 are not essential. However, it has been found that they are useful, insofar as they ensure correct positioning of the valve inside the enclosure at the time of inflation. It has also been found that it is preferable to connect the bottom of the pocket to the bottom of the enclosure. However, this measurement is not essential either and the sheets 24 and 25 could be interrupted at the welding line 33 delimiting the bottom of the pocket.

Of course, apart from the fold lines of the sheets which are straight so as not to create puckering problems in the folded strips, the rest of the periphery of the enclosure may have a shape other than quadrangular. For this, it suffices to cut the sheets to the desired shape, before or after welding, the welding lines then following this shape.

It should also be noted that the packaging according to FIGS. 1 to 5 could also be provided with a part extending to the former. térieur of the enclosure beyond at least one of the welds 35 or 36, this part being able to be used to spare a handle for example, or to form a flap to protect the access to the valve.

FIG. 6 represents a quadrangular sheet 40 in which an orifice 41 has been drilled which has been covered with a cover 42.

This sheet 40 is cut from a roll unwound flat on a horizontal or vertical production line in a hydrogen peroxide bath in order to guarantee the aseptic nature of the packaging material. The unwinding of the film or sheet takes place parallel to the top and bottom seals of the bag. The valve which will be described first of all the manufacture is carried out in stages in the direction of the unwinding of the film reel.

FIG. 7 shows this same sheet 40 of which a marginal strip 40a has been folded over the front face of the sheet 40 at the center of the orifice 41. The marginal strip 40a is welded by two oblique parallel welds 43, 44 delimiting this which will be the valve and by welds 45,46,47 parallel to the fold line of the marginal strip 40a connecting each end of the welds 43,44 to the two lateral edges of the sheet 40.

FIG. 8 shows the fold back in the other direction (arrow F) than previously of the marginal strip 40a with the part 40b of the sheet 40 to which it was welded.

FIG. 9 shows the welding 46a of the sheet 40 to the strips 40a and 40b along the same welding line as the welding 46. The purpose of this welding 46a is to allow the guiding of a straw between the oblique welding lines 43 , 44 delimiting the valve.

In FIG. 10, the formation of a sachet constituting the sealed enclosure has been shown. In addition to the sheet 40 and the valve, the formation stages of which have just been described, the sachet comprises a quadrangular sheet 48 of the same dimensions as the sheet 40 provided with its valve and a bellows 49 intended to form the bottom of the sachet to hold in a vertical position on a horizontal surface. 8

Except for this difference, the formation of the valve which one sees on figure 13 corresponds in all points to what is described and represented in relation to figures 5 to 9, so that one left the same figures of references for this part of the enclosure.

To make this enclosure, a sheet 60 of the same dimension as the sheet 40 is formed, but provided with a bellows 61, 62 formed on each of the opposite lateral edges. Four welds are formed (FIG. 15), two welds 63 to fix the bellows 61,62 to the sheet 40 and two welds 64 to stiffen the bag.

Figure 16 shows the welding of the bottom 65 while an opening 66 is left at the top of the bag to allow filling. The bag closed by a weld 67 (Figure 17) can be placed on the bottom weld 65 which will flatten under the weight of the liquid, while the channel formed between the welds 43 and 44 forming a valve allows access to the drink. after perforation of the cover 42.

The variant of Figure 18 shows the bag of Figure 12 in which the weld 46a has been removed and the valve channel formed between the welds 44 'and 50 (parallel to the edge of the bag and no longer obliquely) is more elongated so to form between the welds 44 ′, 45 ′ and 51 a pocket intended to receive the straw 56. In fact, since the packaging constituted by the sealed enclosure is specially designed to allow the drink to be consumed in several installments, it is useful to have a storage space for the straw 56, this being essential for entering the enclosure through the channel formed between the welds 44 'and 50. The pocket containing the straw can be provided with a system of closure of the self-adhesive strip type along its upper edge in place of the weld 46a of FIG. 12 or of a closure known under the brand Mini-grip ^R.

According to another variant, a pocket 68 can be provided in one of the sheets 40 or 48 forming the wall of the enclosure, this pocket 68 serving as a housing for the straw.

The waterproof enclosure described so far is made from a sheet forming at least one wall of the enclosure To allow the welding of the bellows 49 at the bottom of the sheets 40 and 48 without the external faces of the bellows being welded together, it consists of a laminate whose inner layer is made of a thermoplastic, for example polyethylene and whose the outer layer is made of a thermosetting material, for example OPA.

Figure 11 shows the two lateral welds 50,51 connecting the sheets 40 and 48 to each other and ^" are the two bottom welds 52,53 connecting the bellows 49 respectively to the sheets 48 and 40. On the other hand, the edge upper of the sheets 40 and 48 is not welded, leaving an opening 54 for filling the enclosure.

Finally, FIG. 12 illustrates the packaging finished with the upper edges of the sheets 40, 48 joined by a weld 55. A straw 56 is engaged in the conduit formed between the welds 43 and 44 forming the valve and is also fixed on the face outer of sheet 40 by adhesive tape 57.

To consume the drink, it suffices to remove the adhesive 57 to release the straw 56 and to push it towards the inside of the enclosure by perforating the cover which can be a fine aluminum pellet. When the straw 56 is removed, the two walls of the channel formed between the welds 43 and 44 close and if the enclosure is turned over, the pressure exerted by the liquid closes this channel hermetically. As a variant, instead of the opening 41 and the cover 42, the opening can also be replaced by a pre-cutting of the film 40.

As we have seen from the above description, the production process allows a perfectly aseptic packaging of the drink.

The embodiment of FIGS. 13 to 17 relates to the manufacture of bags with lateral bellows intended to be produced on a production line whose axis of the machine is parallel to the vertical axis of the bag. The position of the valve must be such that the folding operations are carried out continuously in the axis of the machine. This constrain¬ you involves positioning the valve on a lateral part of the bag. 10

practiced on the valves of the previous embodiments.

Finally, the marginal strip 71 in which the valve is formed is folded over the rear face of the sheet 70 relative to FIG. 20e, as shown in FIG. 20f after which the enclosure is finished as in the previous embodiments , by welding another sheet identical to sheet 70, along the free edge of the marginal strip (FIG. 20f) and along the three sides of the sheet 70 not adjacent to this free edge, thus closing the enclosure on four sides.

The variant of FIGS. 21a to 21d differs from the previous one by the only fact that the valve, produced in a material other than the sheet 70 ', intended to form a wall of the sealed enclosure, is formed as before by folding and welding before to be attached to sheet 70 '. We start from a separate strip 71 'folded in half (Figure 21a) and form a weld 73 along the fold. The non-convergent welds 74, 75 and the weld 76 connecting one of the ends of the non-convergent welds 74 are cleaned. 75 at the transverse edges of the strip 71 ′, the cut between the welds 74, 75 in the weld 73 of the strip (Figure 21c), preferably cuts 74a, 75a are made over part of the length of the welds 74, 75. Then (Figure 21d), one of the free edges of the strip 71 'is welded to an edge of the sheet 70 'and the enclosure is terminated by welding a second sheet (not shown) at least in the case of a single-wall enclosure, as in the previous embodiments. It is obviously also possible to fix one or more bellows as described above between the two sheets.

As another alternative to the embodiments of FIGS. 20 and 21, the same result can be obtained by starting, as before, from a single multilayer sheet 84 having a different marginal part, for example monolayer 85 in which the valve is formed as explained previously.

The embodiment of FIG. 18 proposes to produce a pocket for accommodating therein a straw 56, intended to consume the liquid content of the enclosure. Figure 23 illustrates a and in a marginal strip from which there is obtained by folding and welding, as described above, a valve making it possible to control the flow of a fluid in or out of the sealed enclosure and to keep this enclosure closed.

This embodiment necessarily assumes that the sheet forming this wall of the enclosure and the valve are made of the same material of the same thickness. However, the valve to close properly requires a very flexible material and as thin as possible. On the other hand, it may be desired that the wall of the enclosure is thicker and that it is preferably made of a laminated material such as PE / X / PE, X being a gas-tight varriere such as polyethylene vinyl alcohol (EVOH ), polyamide (PA) or biaxially oriented polyamide (OPA), whereas such a laminate is of no particular interest for the valve.

This is the reason why it has been imagined to produce the sheet 70 (FIG. 20) and the marginal strip 71 in two different thicknesses of the same material or of different materials. Thus the sheet 70 will be made of a laminate material mentioned above, while the marginal strip 71 will be formed from a single layer of PE. This sheet 70 and this marginal strip are unwound from two reels and arranged edge to edge (FIG. 20a) then welded to one another by a weld 72 (FIG. 20b). Then, the marginal strip 71 is folded in the middle of its width (Figure 20c). A weld 73 is produced along the fold and two parallel welds 74, 75 between the weld 73 and a parallel weld 76 as in the previous embodiments, this weld 76 being interrupted between the welds 74 and 75.

Then (FIG. 20e), the weld 73 is cut between the parallel welds 74, 75 to form the channel and two cuts 74a, 75a are provided in the middle of the width of the welds 74, 75. These cuts are intended to release part of the length of the valve of the marginal strip 71 in which it is formed, making it possible to increase the efficiency of the pressure exerted on the external faces of the valve and serving to close it as explained above. It should be noted that these cutouts can advantageously also be 1 2

packaging of a liquid, allowing partial removal of the straw above the level of section 91a, leaving it in the upper part of channel 91, the lower part of channel 91 closing, even if the straw is engaged in the upper part of channel 91. Of course, this form of valve can be used in the case of all the previous embodiments of chambers intended for the packaging of liquids. The straw could moreover be replaced by a pouring spout, in particular in the case of the packaging of liquid products other than drinks.

All the previous embodiments show a cutout 32, 41 formed in the fold of the sheet between the parallel welds 30, 31 or 43, 44 etc. sparing the valve channel. Alternatively and in particular in the embodiments of Figures 20 and 21 where the valve is made of a material other than the walls of the enclosure, one could use for the valve a very thin film, not cut or precut in the fold of the film, made of a material having elastomeric properties of sufficient elasticity not to deform in a non-elastic manner by the stress resulting from the introduction of the straw into the channel and capable of being perforated by the straw when it reaches the bottom of the undrilled channel. Such a film can be produced in polyolefins such as terpolymers comprising ethylene, propylene and a long diene chain such as the Halifax XTR ^R , Teclar ^R , Royalene ^R or Trefsin ^R.

All of the embodiments described can be produced from infinite lengths of sheet or film material until sealed enclosures are obtained which are then separated from each other. The advantage of this manufacturing process lies in the fact that both the formation of the valve and that of the enclosure, with two or four walls, are carried out by folding and / or longitudinal welding, as and when sheet material advance. Therefore, the valve once made, if it is obtained in a sheet material other than that of 1 1

variant of this embodiment in which the single-wall enclosure with the valve is of the same type as in the embodiment of Figure 11. However, this variant differs from the fact that an external pocket is provided between an outer wall of the enclosure and a third wall 77 welded on three sides 78, 79, 80 to the corresponding edges of the enclosure, but stopping at a certain distance from the fourth side 81, thus allowing access to the inside of the pocket intended to receive a straw 82. The opening of this pocket is closed by an adhesive strip 83 which extends from the edge 81 of the enclosure to below the upper non-welded edge of the sheet 77. In this variant, the sheet forming the wall of the enclosure adjacent to the pocket may be the sheet integral with the valve similar to the valves of the embodiments described above. Since this wall is covered by the sheet 77 forming the pocket and by the self-adhesive strip 83, the sheet forming this wall and the valve can be made of a material thinner than that of the other wall of the enclosure and sheet 77.

The variant illustrated in FIG. 24 shows an enclosure 90 provided with the valve formed between two parallel welds 86, 87 connecting two welds 88, 89 extending between two opposite edges of the enclosure 90. The parallel welds 86, 87 are arranged so as to each form a progressive thickening 86a, 87a in the channel 91 of the valve, narrowing the section of the latter in the form of a funnel to a point where the welds 86, 87 suddenly resume their thickness initial. The large section of the funnel thus formed is turned towards the outside of the enclosure 90 and the smallest section is directed towards the inside. The ratio of the lengths between the inlet of the channel 91 and the weakest section 91a of the funnel, on the one hand and this weakest section 91a and the end of the channel 91 opening into the enclosure 90, on the other hand, is about 2/3, 1/3. The purpose of this valve, the channel 91 of which is divided into two parts, the border of which is situated at the level of the weakest section of the funnel 91a, is, in the case of an enclosure of 14

The variant illustrated in FIGS. 27 and 28 relates to a manufacturing process in which is integrated a unit for filling the enclosure with a liquid product intended to be packaged in this enclosure. As in the previous example, one starts with two films 100, 101 respectively to produce the valve 102 in the same manner as previously, by folding unequal widths 100a, 100b, the edge of the part 100a being welded to an edge of the film. 101.

Then, the film 101 with the valve 102 is put in tubular form around a filling hopper 103 and a longitudinal weld 104 (FIG. 28) is produced between the edge of the part 100b and the other edge of the film 101, closing thus the tubular element formed around the hopper 103. Transverse welds 105 are made at regular intervals as the tubular element advances. Between two transverse seals 105, a dose of product to be packaged is poured through the hopper 103 and the sachets thus filled are separated from each other in the middle of the width of the transverse seals 105.

FIGS. 29.30 illustrate yet another method of manufacturing a sealed package which differs from the forms of execution described hitherto by the fact that the channel 106 of the valve 107 is accessed by an opening 108 cut in a film 109 intended to form a wall of the sealed bag. As shown in FIG. 29, instead of forming the valve by folding a sheet, the same result can be obtained by welding the adjacent longitudinal edges of two strips 110, 111 of unequal widths. These two embodiments of the valve are interchangeable and depend on the choice of the manufacturer. Then, as can be seen in FIG. 29, the free edge of the strip 110 is welded to the internal face of the film 109, with the help of a separating guide 112, then it is the edge of the strip 111 which is welded to the same internal face of the film 109 with the help of another separating guide 113. The two respective free edges of the strips 110 and 111 are welded on either side of the opening 108 thus allowing access at channel 106 of valve 107. Finally, a film 114 is unwound and welded at the two edges 1 3

the enclosure itself, is integrated into the enclosure without being cut beforehand, avoiding having to position the valve, which constitutes a complex operation, slowing down the rate and costly in terms of investment.

Figure 25 illustrates a method of manufacturing a sealed enclosure that Figure 26 shows in section. This process is therefore carried out continuously from two films 92 and 93 which are unwound and on which folds and welds are carried out as they advance. The different stages of the process are illustrated by different perspective sections of the sheet materials. It is however specified that these sections are only there to show the various operations carried out but that the sheet materials are only sectioned when the sealed enclosure is finished. We first see the film 92 intended to form the valve. This film 92 is first of all folded longitudinally into two parts 92a, 92b of unequal widths. These two parts are welded by two longitudinal welds 94 with interruption between two parallel oblique welds 95 intended to provide the valve channel. In the next step, a cutout 96 is formed in the fold of the sheet 92 between the two oblique welds 95.

The second film 93 intended to form the sealed enclosure is unwound in the next step, along the edge of the part 92a of the valve formed in the film 92. The separator guide 97 is disposed in the path of the film 92 and is intended to be inserted between the parts 92a, 92b. This separator 97 is intended to allow the welding of the edge of the part 92a with that of the film 93 without the part 92b being welded to them.

In the following steps, the film 93 is shaped to produce the enclosure 98 illustrated in section in FIG. 26, with two lateral bellows 99. Finally, the second longitudinal edge of the film 93 is welded to the longitudinal edge of the part 92b of the film 92, these two longitudinal edges being previously folded at 90 °. Thus, this sealed enclosure has access to the inlet of the channel formed between the two oblique welds 95 located on a large face of the enclosure and no longer in an edge thereof as so far. 16

a film 120 welded like all the preceding valves to part 118a. Finally, the free edge of film 120 is welded to the adjacent edge of film 119. Thus, it has been shown that the valve can be integrated into a wall αe the sealed enclosure as in the case of FIGS. 1 to 19, that the valve can be produced in a film separate from that of the sealed enclosure as in the case of FIG. 20, that the valve can be produced using two films (FIG. 29) and finally that it can be produced by a film welded to a folded film of a wall of the bag. In all cases, the valve is obtained continuously with the sealed enclosure and therefore passes through the bag between two opposite edges of this sealed enclosure.

It is obvious to a person skilled in the art that the enclosure described above with its tight closing valve can be produced on other types of machine and that other embodiments are possible within the framework of the invention. defined by the claims.

1 5

longitudinal of the film 109. Then, as in all the previous embodiments, all of the superimposed films and, for example, only welded longitudinally except for the channel 106, are welded transversely and cut in the middle of the width of the transverse seal to separate the bags.

In the various embodiments of the method according to the invention described so far, when it is not desired to weld together all the thicknesses of superimposed films but only some of them, a separator is inserted between the films, produced in a material which cannot be welded with that of these films. Alternatively, the separator can be replaced by a heat-resistant varnish applied to the back of the film, the obverse of which must be welded, this varnish conforming to the shape of the weld or welds to be made on the face to be welded. Thus, the valve can be welded at the same time as the valve is welded to the film forming the walls of the sealed bag, by coating the valve film with such a varnish at the location of the valve formation welds. For example, the heat-resistant varnish could be a polyurethane varnish or an acrylic varnish.

FIG. 31 is a variant of the sealed bag illustrated in FIG. 5. In this variant, the film 24 forming the valve 24a, 24b is provided with a cut-out opening 115 blocked by a tongue 116 partially welded or glued to the film 24 to close the opening 115 hermetically. By grasping the non-welded part of the tongue 116, it can be torn off in order to deflate the bag.

This bag also includes a flap 117 welded to the edge 36 and formed by a pocket intended to receive a postal dispatch note. This flap 117 normally covers the tongue 116 sticks to the sheet 26 and thus prevents accidental tearing of this tongue.

Finally, FIG. 32 shows a last variant of the sealed enclosure in which the enclosure is formed of two films 118, 119, the film 118 being folded back to form one of the parts 118a of the valve, the other part of which is formed by

Claims

18

sheet (70) and this strip (71), the free edge of this strip (71) as well as the free edges of said sheet (70) being tightly assembled to the adjacent edge of a second wall, applied against the face of the first wall (70) adjacent to said marginal strip so as to form said enclosure, containing said folded marginal strip.

3. Sealed enclosure, in particular intended to be inflated, according to claim 1, characterized in that the two said connecting lines (30, 31) stop at a distance from the free edge of said strip (24a) adjacent to the opening. inlet of the conduit, and that the latter is fixed to said sheet (24) by a first assembly line (28) parallel to said free edge and passing through the respective ends of said two connecting lines (30,31) s 'stopping at a distance from this free edge, and by a second assembly line (29) substantially following the opposite edge (29') to said free edge of said strip (24a), these first and second assembly lines (23, 29) fixing said marginal strip (24a) to said sheet (24) stopping in said zone extending between the two said non-convergent connecting lines (30,31).

4. Sealed enclosure, in particular intended to be inflated, according to claim 3, characterized in that it comprises four superimposed walls, (24,25,26,27) assembled to each other on at least two opposite sides, both outer walls (26,27) and the two inner walls (24,25) being assembled respectively to each other on a third side (37) forming the bottom, while each outer wall (26,27) is assembled to the adjacent internal wall (24,25) along the fourth side (35,36), thus forming a pocket inside the enclosure.

5. Sealed enclosure, in particular intended to be inflated, according to claim 4, characterized in that the four superimposed sheets (24,25,26,27) have adjacent contours and are .assembled over their entire periphery except along the opening of said pocket where the edges of the internal walls (24,25) are separated from each other.

6. Waterproof enclosure, in particular intended to be inflated, 17

1. Watertight enclosure provided with a valve, at least part of which extends inside the enclosure and is formed between two flexible sheets (24a, 24b; 40a, 40b) joined according to two non-converging connecting lines ( 30,31,43,44) to form a conduit between them by spacing said flexible sheets (24a, 24b, 40a, 40b) from one another, allowing the passage of a fluid between the interior and the outside the enclosure, these sheets (24a, 24b, 40a, 40b) being intended to be pressed against each other as soon as one ceases to apply a force to them to spread them apart, thus preventing said fluid from leaving of the enclosure, characterized in that said flexible sheets (24a, 24b, 40a, 40b) extend between two opposite edges of the enclosure, that these sheets are tightly connected to each other said non-converging connecting lines forming said conduit at said opposite edges of the enclosure and that the edges of these sheets, adjace nts at the inlet end of said duct are tightly connected to at least one wall of said enclosure, on either side of an access passage at the inlet end of said duct.

2. Sealed enclosure according to claim 1, characterized in that said duct is formed in a marginal strip (71) adjacent to an edge of a sheet (70) forming at least one of the walls of said enclosure, this marginal strip being folded around a line (73) parallel to said edge of said sheet (70), two non-converging tight connecting lines (74,75) joining the two parts folded over one another of said marginal strip (71 ), these lines (74,75) starting from the folded edge (73) in the direction of the opposite parallel edge of this marginal strip the two parts thus folded are themselves applied against one face of said sheet (70) with the free edge of the marginal part (71) situated substantially adjacent to the respective adjacent edges of said sheet (70) and of said marginal strip (71), forming a fold between this 20

by a strip welded to the edge of said sheet, this strip and this sheet being made of two different materials.

15. A tight enclosure according to claim 13, characterized in that said marginal strip (85) consists of one of the layers from which the sheet (84) is formed, forming at least one of the walls of the enclosure.

16. A sealed enclosure according to claim 2, characterized in that a cutout (74a, 74b) is provided over a portion of the length of each of said assembly lines (74.75) in the middle part of their width. starting from said folded edge.

17. A sealed enclosure according to claim 1, characterized in that said non-converging connecting lines (36,87) each have a progressive widening (86a, 87a) extending in the channel (91) of the valve going from the outer end to the inner end of this channel, this widening stops suddenly, the channel (91) being thus divided longitudinally into two portions, an outer portion intended to serve as a receiving element of a distribution conduit liquid and an internal portion closing the valve and the opening of which is controlled by the longitudinal displacement of the end of said tubular member from the external portion to the internal portion of said channel (91).

18. Sealed enclosure according to claim 1, characterized in that a third rectangular wall (77) is fixed along a portion of the length of two opposite edges (78,80) of the enclosure and along the edge (79) connecting these two opposite edges so as to form an open pocket along its fourth side, this pocket being closed by an adhesive strip (83), covering the part of the wall of the enclosure not covered by this third wall (77).

19. A sealed enclosure, in particular intended to be inflated according to claim 4, characterized in that one of its walls (24) is perforated (115) and that a tongue (116) is glued or welded to the external face of the wall (24) for hermetically closing the opening, an unglued or welded part of this tongue (116) serving as a gripping element to release the opening (115). 19

according to claim 4, characterized in that the two internal walls (24,25) are joined to one another (33) to form a pocket inside the periphery of the enclosure and the opening of which is located opposite the opening of the enclosure.

7. Waterproof enclosure, in particular intended to be inflated, according to claim 6, characterized in that the edges of the pocket delimited inside the periphery of the enclosure are flared.

8. A tight enclosure according to claim 1, characterized in that a bellows (49; 61.62) is interposed between at least two adjacent edges of the two walls (40,48) of said enclosure and is welded to each of these edges.

9. A sealed enclosure according to claim 8, characterized in that said bellows (49; 61.62) is constituted by a laminate whose internal layer coming into contact with the respective adjacent edges of said walls is made of heat-weldable thermoplastic material. and whose outer layer is made of a non-heat sealable material.

10. A sealed enclosure according to claim 8, characterized in that said cutting (41) is carried out before folding said marginal strip and that this cutting is closed using a perforable seal (42).

11. Sealed enclosure according to one of claims 2 and 8, characterized in that a pre-cutting of said sheet is carried out in the area between the two assembly lines (43,44) intended to be perforated by introduction a rod between the assembly lines (43,44).

12. Waterproof enclosure according to claim 2, characterized in that a cutting or pre-cutting (32,41) interrupts the fold (29,45) in the zone extending between the two assembly lines (30 , 31,43,44) to allow the passage of the fluid in the conduit thus formed.

13. A tight enclosure according to claim 2, characterized in that said marginal strip is formed by a strip of the sheet forming at least one of the walls of the enclosure.

14. A sealed enclosure according to claim 2, characterized in that said marginal strip (71.71 ′) is made up 20. A tight enclosure according to claim 19, characterized in that a flap is fixed in the extension of one of the walls of the enclosure and is capable of being removably attached to this enclosure by covering said tongue. (116).

21. Method for packaging a drink in the sealed enclosure according to one of claims 1, 2 and 7, characterized in that said valve (30,31,43,44) adja¬ cente is first formed one of the edges of one of the walls (24,40) of the enclosure, the second wall (26,48) of the enclosure is scanned to the first wall so as to close the bottom of the enclosure as well as the lateral edges, a metered quantity of liquid is introduced between the non-welded edges of the upper edge of the enclosure and the enclosure is closed by welding the two upper edges to one another (35,55,57).

22. A method of manufacturing the sealed enclosure according to one of claims 1-20, characterized in that both the valve and the sealed enclosure are made from endless sheet material like gold, scrolls in overlapping the different sheets as and when scrolling by folding and / or adding other sheet material and welding parallel to the running direction apart from said two non-converging connecting lines and finally welded transversely to the running direction different sheets of sheet material on either side of the same valve and the sealed enclosures thus obtained are separated from each other, along said transverse welding lines.