FR3021038A1 - WELDED RIBBON SACHET - Google Patents

Abstract

The invention relates to a bag (100) having a closure device (120), the closure device (120) comprising: - a first channel (130) and a second channel (140) extending between the edges ( 117, 118) of the bag, and - a first ribbon (136), housed in the first channel (130), and a second ribbon (146), housed in the second channel (140), the first ribbon (136) protruding the first end (132) of the first channel (130) and the second band (146) projecting from the second end (144) of the second channel (140), the first band (136) and the second band (146) being soldered to the second edge (118) of the bag (100).

Description

FIELD OF THE INVENTION The present invention relates to the field of sachets. More specifically, the present invention relates to the field of bags whose closure is provided by pulling on ribbons or cords. In the remainder of the description, the term "cord" or "ribbon" will be used interchangeably without this being considered as limiting. The term cord or tape as used in the context of the present patent application covers in particular any type of cord, tape, wire or equivalent means capable of fulfilling the function corresponding to the present invention. STATE OF THE ART It has already been proposed many bags comprising a closure cord. For example, FIGS. 1 and 2 are shown respectively in a perspective view and in a cross-sectional view of a bag of this type known from the state of the art. FIG. 1 shows a bag 10 comprising two main sheets 12, 14. The sheets 12 and 14 are generally rectangular and parallel to one another. The sheets 12 and 14 are connected at a bottom 16 and two sides 17, 18 opposite each other, parallel to each other and perpendicular to the bottom 16, and an open mouth 19 opposite the bottom 16. The bag 10 FIG. 1 furthermore comprises, near the mouth 19, two series of parallel channels 30, 32 and 40, 42 respectively receiving a drawstring or closure tape 31, 33 and 41, 43. A first series of channels comprises two parallel channels 30, 32 adjacent the mouth 19 respectively on each of the two sheets 12, 14.

A second series of channels comprises two other channels 40, 42 parallel to each other, respectively on each of the two sheets 12, 14 set back from the mouth 19. Each of the two channels 30, 32 of the aforementioned first series receives a cord strand 31, 33. These two strands of cords 31, 33 are interconnected by nodes 35, 36 on either side of the bag 10, on the outside of the bag 10. Each of the channels 40, 42 of the second series receives a strand of cord 41, 43. The two strands 41, 43 are interconnected by nodes 45, 46 on either side of the bag 10, on the outside of the bag. By pulling on respective opposite ends of the two sets of cords, for example by pulling in opposite directions respectively on the nodes 35 and 46 as shown diagrammatically in FIG. 1 by the arrows referenced A and B, a tightening is obtained, then the closure of the mouth 19 of the bag 10. In theory the cordet bags of the type illustrated in Figures 1 and 2 attached are of real interest insofar as they allow in principle a simple opening and a simple and reversible closure of the bags 10. However, it is difficult to make these bags 10 simply and quickly. It is indeed necessary, on the manufacturing line to tie together the strands 31 and 33, 41 and 43 in order to make knots. However, this knot requires the use of specific machines and slows the pace very strongly. Moreover, there is a significant risk of having to stop the production line at the knotters (which make the knots on the strands). It is also not possible to deliver sachets comprising strands 31, 33, 41, 43 not tied. Of course, the rate of manufacture of the bags could be significantly increased, but the strands would likely exit their respective channels 30, 32, 40, 42 during the handling of the bags.

But the field of cordsets has clearly been the subject of little remarkable innovation for many years. On the other hand, it should be noted that in practice the cordet bags of the type illustrated in the accompanying FIGS. 1 and 2 tend to fall into disuse. Document WO 2006/110415 has proposed, in the field of the packaging of hygienic products, a bag comprising, at the mouth of the mouth, two peripheral channels in which are housed strands of a closure cord. The strands are welded to the edges of the bag, and the channels further include a cutout opening into the top edge of the bag allowing a user access to the strands. By pulling the strands through the cuts, the user can then bring the edges of the bag close and thus close the mouth. This closure system has the advantage of avoiding the formation of 15 knots at the ends of the strands, the strands being held by the edges of the bag with the aid of a weld. However, this system requires placing the channels and the cord at the free end of the mouth of the bag, and therefore can not be used for bags requiring closure at a distance from the mouth. Furthermore, in use, it is difficult to close the bag in a relatively tight manner, since when pulling on the strands to close the bag, there is generally a non-negligible hole between the sheets of the bag. bag. This type of bag is therefore not suitable for use in other areas than sanitary products, and in particular in the field of food. SUMMARY OF THE INVENTION The object of the present invention is to improve the known pouch bags in order to facilitate their uses, in particular to facilitate the closing and opening of such pouches. An auxiliary object of the invention is to allow to restart the development of the string bags.

The aforementioned objects are achieved according to the present invention by means of a bag having a first sheet and a second sheet together forming a first edge and a second edge of the bag, and a closure device, the closure device comprising: a first channel and a second channel extending between the edges, the first channel and the second channel each comprising a first end and a second end, and - a first ribbon, housed in the first channel, and a second ribbon, housed in the second channel, the first ribbon projecting from the first end of the first channel and the second ribbon projecting from the second end of the second channel, the bag being characterized in that the first ribbon is fixed by welding to the first channel, in an area adjacent to the second end of said first channel, and the second ribbon is attached by welding to the second channel, in an area adjacent to the first end of said second channel, the first end of the first channel and the second end of the second channel being adjacent to the first edge of the bag. Some preferred but non-limiting characteristics of the bag are the following: the first ribbon is welded to the second end of the first channel and the second ribbon is welded to the first end of the second channel; the first ribbon and the second ribbon protrude from the first ribbon; first channel and the second channel, respectively, at the first edge of the bag, - the second channel is closer to a mouth of the bag than the first channel, so that the first channel and the second channel are offset and not do not superimpose, - the first and second ribbon are made of a heat-sealable material, - the heat-sealable material comprises at least one of the following polymers: polypropylene and its copolymers, polyethylene and its copolymers, high-density polyethylene, low-density polyethylene, the sheets comprise an inner face formed of a heat-sealable material, and wherein the material constituting the first and second ribbons are identical to the material constituting the inner layer, the first and the second ribbon are made of a non-weldable material, the first and the second ribbon are made of cotton or polyester, the first channel and the second channel are adjacent to a mouth of the bag, or extend at a distance at least two centimeters, preferably at least three centimeters, from a mouth of the bag, the free ends of the ribbons are fixed together with in order to form a loop, and - the first and second tapes have a contact surface 15 with the first and second channels defined respectively so as to improve the setting of the welding of the first and second channels on the first and second tapes respectively. According to a second aspect, the invention also proposes a method of manufacturing a bag as described above, comprising the following steps: - bringing a film on a forming machine, - bringing a first and a second ribbon on the film, - forming a first and a second channel on the film, - folding the film on itself so as to form the first and second sheet of the bag, - solder the first sheet on the second sheet, so as to form a first edge and a second edge of the bag, the first sheet and the second sheet respectively comprising the first channel and the second channel extending between the edges, the first channel and the second channel each comprising a first end and a second end; , the method being characterized in that the first ribbon is soldered to the first channel, in an area adjacent to the second end of said first channel, and the second ribbon is t attached by welding to the second channel, in an area adjacent to the first end of said second channel, the first end of the first channel and the second end of the second channel being adjacent to the first edge of the bag. Some preferred but nonlimiting features of the manufacturing method are as follows: the first channel and the second channel are positioned offset on the first sheet and the second sheet, respectively; the method further comprises a step in which notches are formed in the film in an area corresponding to the first end of the first channel and the second end of the second channel, so that during the soldering step of the first edge and the second edge of the bag, the first and the second ribbons are not welded to the first edge of the bag, - the first channel and the second channel are formed by folding on itself a top of the sheets at the mouth or by welding a band on the sheets of the bag, and - the step of welding the first and second ribbons to the first and second channels and the welding step of the first sheet on the two sheet is performed simultaneously. According to a third aspect, the invention also proposes a machine for the manufacture of a bag as described above and comprising: - a device configured to bring a film to a forming machine, - a device configured to bring a first and a second ribbon 30 on the film, - a device configured to fold the film on itself so as to form the sheets of the bag, - solder bars, configured to weld the first sheet on the second sheet, so as to forming a first edge and a second edge of the bag, the first sheet and the second sheet respectively comprising a first channel and a second channel extending between the first edge and the second edge, the first channel and the second channel each comprising a first end and a second end, the machine being characterized in that it further comprises welding jaws configured to weld the first ribbon to the channel, in an area adjacent to the second end of said first channel, and the second band at the second channel, in an area adjacent to the first end of said second channel, the first end of the first channel and the second end of the second channel being adjacent at the first edge of the bag.

Some preferred but non-limiting features of the machine are the following: the machine further comprises a device configured to form notches on the film, in an area of the film intended to receive the first end of the first channel and the second end of the second channel, and - the welding bars have, in a welding face, a notch configured to come opposite the first end of the first channel and the second end of the second channel.

BRIEF DESCRIPTION OF THE DRAWINGS Other features, objects and advantages of the present invention will appear on reading the detailed description which follows, and with reference to the accompanying drawings given as non-limiting examples and in which: FIGS. and 2 previously described are an external perspective view of a bag according to the state of the art, and a cross-sectional view of the same bag known in the state of the art; FIG. 3a is an external perspective view of a bag according to a first embodiment of the present invention; Fig. 3b shows an outer perspective view of a pouch according to a second embodiment of the present invention; - Figure 4 shows a schematic view of the bag of Figure 3a in substantially closed position; FIG. 5 represents a cross-sectional view of the bag illustrated in FIG. 3a; FIG. 6 represents a cross-sectional view of a bag according to a variant of the embodiment illustrated in FIG. 5; FIG. 7a is a diagrammatic detail view of a first example of welding the first ribbon at the second end of the first channel of a bag according to one embodiment of the invention; FIG. 7b is a diagrammatic detail view of a second welding example of the first ribbon at the second end of the first channel of a bag; FIG. 8 is a diagrammatic detail view of the mechanical assembly of the first ribbon on the second end of the first channel of a bag according to a variant of the embodiment illustrated in FIG. 7a; FIG. 9 is a schematic representation of an exemplary embodiment of a machine for manufacturing a bag according to the invention; FIG. 10 is a longitudinal sectional view of an exemplary embodiment of solder bars that can be used for the manufacture of a bag according to the invention, said welding bars being in position for welding the sheets and forming edges ; and FIG. 11 is a flow chart showing various steps of an exemplary embodiment of the method of manufacturing a pouch according to the invention. DETAILED DESCRIPTION OF AN EMBODIMENT 302 103 8 9 The pouches according to the present invention may be the subject of numerous variants which will not all be described in detail below. Preferably the bag 100 comprises a first sheet 112 and a second sheet 114 parallel and adjacent at rest, interconnected on three of their sides corresponding to a bottom 116 and two side edges 117, 118 parallel to each other and orthogonal to the bottom 116 Such a bag 100 can be made according to many methods known to those skilled in the art. The bag 100 can be made using an element designed as a tubular extrusion or blowing so that a bag blank is in the form of a tube. This tube is closed, for example by welding, at its bottom 116 to close one end of the bag 100.

Such a bag 100 can also be made by folding a film on itself, for example at an edge corresponding to its bottom 116 while then ensuring the welding of the two sheets 112, 114 carried adjacent to the edges 117, 118 It is also possible to ensure the folding of the film at one of the edges 117, 118 by providing a weld at the bottom 116 and the complementary edge 118 or 117. Preferably, the material constituting the film is a heat-sealable material, in particular a thermoplastic material that can be welded. The plastic material may in particular belong to the family of polyolefins and comprise at least one of the following materials: polyethylene, polypropylene, low density polyethylene, high density polyethylene, or a copolymer of these monomers. The sheets 112, 114 may be transparent. They may, however, be provided with any appropriate printing or decoration. The sheets 112, 114 may also be made from a composite material, for example by incorporating sheets of paper and / or metal, for example into a sandwich structure. In this embodiment, the film in the composite material comprises an inner face 113 formed of a heat-sealable material, especially a thermoplastic material. The plastic material may in particular belong to the family of polyolefins and comprise at least one of the following materials: polyethylene, polypropylene, low density polyethylene, high density polyethylene, or a copolymer of these monomers. The sheets 112, 114 are chosen from a material and of a thickness which makes it possible to guarantee sufficient flexibility for the bag to allow its closure by necking of a mouth 119 opposite the bottom 116. The sheets 112, 114 are therefore flexible.

The bag 100 further comprises a closure device 120 comprising: - a first channel 130 and a second channel 140 extending between the edges 117, 118, the first channel 130 and the second channel 140 each comprising a first end 132, 142 and a second end 134, 144, and - a first ribbon 136, housed in the first channel 130, and a second ribbon 146, housed in the second channel 140, the first ribbon 136 projecting from the first end 132 of the first channel 130 and the second ribbon 146 protruding from the second end 144 of the second channel 140. The first ribbon 130 is attached to the first channel 130, in an area adjacent to its second end 134, and the second ribbon 146 is attached to the second channel 140, in an area adjacent to its first end 142. The ribbons 136, 146 can then be welded either directly to the free ends 132, 144 respectively (see FIG. 7a), or else ble distance of these free ends 132, 144 (see Figure 7b). Moreover, as can be seen in FIG. 3, the first end 132 of the first channel 130 and the second end 144 of the second channel 140 are adjacent to the first edge 117 of the bag 100. Thus, the first strip 136 and the second strip 146 make protruding from their respective channel 130, 140 at the same edge 117 of the bag. The closure of the bag 100 is therefore effected by pulling on the ribbons 136, 146 in the extension of their respective channel 130, 140, in the same direction, by grasping the first edge 117 of the bag at which the ribbons 136 project, 146. In order to reverse the opening of a bag, it suffices to loosen the mouth 119 to obtain the opening of the mouth by inverse sliding of the ribbons 136, 146 in the channels 130, 140. It will be understood that the fixing of the ribbons 136, 146 at the ends 134, 142 of their respective channel 130, 140 makes it possible to block the ribbons 136, 146 in the channels 130, 140 without having to form a node at their free end. Furthermore, this embodiment has the advantage of avoiding running the ribbons 136, 146 along the mouth 119 on the two sheets 112, 114 of the bag 100. The manufacture of the bags 100 is therefore clearly simplified, which makes it possible to multiply by two or even three the rate of manufacture of the bags. In addition, this embodiment has the advantage of allowing the closure device 120 to be produced at the mouth 119 or at a distance therefrom. For example, the closure device 120 may extend in the first quarter of the bag 100, typically two, preferably three centimeters from the mouth 119. A decorative effect is thus obtained when the bag 100 is closed as illustrated in FIG. Figure 4, the mouth 119 taking a flared tulip shape. Furthermore, the closure device 120 according to the invention makes it possible to simplify and improve the closure of the bag 100, in comparison with the conventional bag-and-cord bags. Indeed, the ribbons 136, 146 no longer form a loop surrounding the mouth 119 of the bag but comprise a single strand which extends between the two edges 117, 118 of the bag 100: during traction on the strands by a user therefore, the ribbons 136, 146 are no longer susceptible to turning in the channels 130, 140, which tends to reduce the efficiency of the efforts of the user. Moreover, unlike the bag described in WO 2006/110415, the tensile stress on the ribbons 136, 146 is applied in the direction of extension of the channels 130, 140 and not perpendicular thereto, which simplifies and significantly improves the approximation of the edges 117, 118 and therefore the closure of the bag 100. The bag 100 is therefore better closed, leaving only a small open passage or no passage. The first channel 130 is preferably affixed to the first sheet 112 while the second channel 140 is attached to the second sheet 114 to improve the closure of the bag 100. The first channel 130 and the second channel 140 may be staggered. relative to each other according to the height of the bag 100 (see FIG. 3b), that is to say that the second channel 140 may be closer to the mouth 119 of the bag than the first channel 130, so that they do not overlap when the bag 100 is laid flat. This offset of the first and second channels 130, 140 makes it possible, when the bag 100 is closed by pulling on the ribbons 136, 146, to deform the channels 130, 140 and therefore the mouth 119 by bringing the first channel 130 and the second channel closer together. channel 140. This deformation has the effect of accentuating the folding of the sheets 112, 114 and thus improving the sealing of the bag 100. Alternatively, the first channel 130 and the second channel 140 may instead be superimposed and not The ends of the first ribbon 136 and the second ribbon 146 may be attached at the second edge 118 of the bag 100 by any suitable means. For example, the ribbons 136, 146 are soldered at the second edge 118 of the bag, as referenced at 138, 148 in FIGS. 3a and 3b. The weld 138, 148 of the ribbons 136, 146 at the edge 118 of the bag 100 has the advantage of greatly accelerating the rate of manufacture of the bags 100. The weld 138, 148 can indeed be carried out very rapidly, using conventional means in the field of packaging bags. The weld 138, 148 may in particular comprise an ultrasonic weld, for example by points. The weld 138, 148 may be wide (depending on the height of the bag) to ensure a good attachment of the ribbon 136, 146 to the second edge 118 of the bag 100. Alternatively, the weld can also be obtained by multiple welding or wire. Furthermore, the welding of the second edge 118 of the bag 100 may in particular be carried out using conventional solder jaws equipped with a counter-element placed between the sheets 112, 114 during the welding of the strips 136, 146, in order to to avoid that the welding of the sheets 112, 114 causes the welding of the first end 132 of the first channel 130 and the second end 144 of the second channel 140. Notches 137, 147 (or clearances) can be formed on the film in the region of the film intended to receive the first end 132 of the first channel 130 and the second end 144 of the second channel 140, to avoid the welding of the strips 136, 146 on the film at the first end 132 of the first channel 130 and the second end 144 of the second channel 140 during the welding of the first edge 117 of the bag 100. The ribbons 136, 146 therefore remain free to move through the ends 132, 144 of the channels 130, 140. If necessary, the notches 137, 147 also make it possible to use ribbons 136, 146 having a length equal to the width (edge 117 at edge 118) of the bag 100, while ensuring good handling of said ribbons 136, 146 to close the bag 100. According to a first embodiment, the ribbons 136, 146 may be made of a heat-sealable material, typically a polyolefin such comprising a polymer or a copolymer among the following materials: polypropylene and its copolymers, polyethylene and its copolymers, high density polyethylene, low density polyethylene. In this way, during the welding of the end of the ribbons 136, 146 to the second edge 118 of the bag 100, the ends of the ribbons 136, 146 merge and form a solid junction with the film forming the edge 118 (see FIGS. 7b). Advantageously, the use of polyolefin tapes 136, 146, and in particular comprising a polymer or a copolymer of polyethylene, polypropylene, low density polyethylene, and / or high density polyethylene, also makes it possible to recycle the bag. To allow the soldering 138, 148 of the ends of the ribbons 136, 146 on the bag 100, the ribbons 136, 146 may also be made of a material compatible with the material making up the sheets 112, 114. For this purpose, the sheets 112 , 114 (or at least their facing face 113) and the ribbons 136, 146 may be made of an identical material or the like. For example, the sheets 112, 114 and the ribbons 136, 146 may be made of polyethylene or polypropylene.

According to a second embodiment, the ribbons 136, 146 are formed in a non-fuse material (such as cotton or polyester for example). In this embodiment, the welding of the second edge 118 of the bag 100 at the second end 134 of the first channel 130 and the first end 142 of the second channel 140 then has the effect of mechanically trapping the corresponding ends of the first and second ends the second ribbon 136, 146 at the second edge 118 of the bag 100. The solder 138, 148 of the edge 118 of the bag 100 at the second end 134 of the first channel 130 and the first end 142 of the second channel 140 produces a shearing effect of the ends of the ribbons 136, 146, making it possible to form connection points between the bag 100 and the ribbons 136, 146. The weld 138, 148 preferably covers the entire width (depending on the height of the bag 100, between its bottom and its mouth 119) of the ribbon 136, 146 and extends in part on the channels 130, 140 around the ribbons 136, 146, so as to ensure an optimum shearing effect. The mechanical assembly can be performed using welding jaws configured to simultaneously weld the second end 134 of the first channel 130 and the first end 142 of the second channel 140, so as to mechanically trap the corresponding ends of the first and second Ribbon 136, 146. The mechanical imprisonment of the ribbons 136, 146 is particularly effective when ultrasonic welding jaws, in particular by points, are used. Such solder jaws effectively provide an optimum shearing effect of the ribbons 136, 146.

Whatever the mode or embodiment of the bag 100, the ribbons 136, 146 may further have a contact surface with their respective channel 130, 140 defined to improve the grip of the weld 138, 148 of the channel 130 , 140 on the ribbon 136, 146. For this purpose, it is for example possible to increase the roughness of the ribbon 136, 146 or to define a shape of the ribbon 136, 146 making it possible to improve the setting of the weld 138, 148 on In particular, a tape 136, 146 in the form of a strip will have a greater contact area than a generally cylindrical strip 136, 146, and thus the setting of the weld 138, 148 on the ribbon 136, 146 will be improved.

Sachets 100 Machine 100 The sachets 100 can then be obtained using a machine 200 comprising: a device 210 configured to feed a film 1 onto a forming machine, a device 220 configured to cut the a device 230 configured to feed a first and second ribbon 136, 146 to the film 1, optionally an apparatus 240 for forming the first channel 130 and the second channel 140 on the film 1 (or variant for bringing the first channel 130 and the second channel 140 onto the film 1), - first solder bars 250, configured to weld the first channel 130 and the second channel 140 on the film 1, - welding jaws 260, configured to weld the first ribbon 136 to the second end 134 of the first channel 130 and the second ribbon 146 to the first end 142 of the second channel 140. The machine 200 may further comprise a device 270 for folding the film 1 of to form the first 112 and the second sheet 114, as well as conventional solder bars 280 for welding the first sheet 112 to the second sheet 114, so as to form the first edge 117 and the second edge 118 of the bag 100. Weld bars 280 may include ultrasound electrodes. The machine 200 may further comprise a device 215 configured to form notches 137, 147 on the film 1, in the region of the film 1 for receiving the first end 132 of the first channel 130 and the second end 144 of the second channel 140. These notches 137, 147 are intended to avoid the welding of the ribbons 136, 146 on the film 1 during the welding step S7 of the first edge 117 of the bag 100. The realization of the notches 137, 147 in the film 1 makes it possible to remove material at the ends 132, 144 to remain free of the channels 130, 140, so that, when welding the first edge 117 of the bag 100 by the welding bars 280, the heat applied by the bars 280 does not have the effect of locally melting the film 1 and welding these ends 132, 144, thus ensuring that the ribbons 136, 146 remain free of movement at these ends 132, 144. In this case, the 280 welding bars can in o In a soldering face 282, it has to be provided with a notch 284 configured to face the notches 137, 147 (see FIG. 10). It will be understood that it is preferable to avoid that the portions of the strips 136, 146 projecting from the channels 130, 140 at the notches 137, 147 are mechanically cut or trapped in the edges 117, 118, when the welding bars 280 weld the first sheet 112 to the second sheet 114, so as to form the first edge 117 and the second edge 118 of the bag 100.

Method S for Making Sachets 100 The sachet 100 may be obtained according to a manufacturing method S comprising the following steps. In a first step Si, a film 1 for forming the sheets 112, 114 of the bag 100 is fed to a forming machine 200. In a second step S2, the ribbons 136, 146 are fed to the film 1, for example longitudinally with respect to a running direction of the film 1. During a third step S3, optional, notches 137, 147 are formed on the film 1, in the region of the film 1 intended for receive the first end 132 of the first channel 130 and the second end 144 of the second channel 140. In a fourth step S4, the film 1 is cut at the notches 137, 147. This cut has the effect of separating the part of the film 1 intended to form the bag of the remainder of the film 1. At this stage of the process S, a film 1 is thus obtained whose length is substantially equal to the final distance between the edges 117, 118 of the bag 100, the film being provided with notches 137, 147 at both ends In a fifth step S5, the sides of the film 1 are folded back on themselves to form the first 130 and second 140 channels, so that the channels 130, 140 extend. parallel to the running direction of the film 1. The sides of the film 1 are then welded to the film 1 by providing one or two weld lines 131, 133; 141, 143 of the fold thus formed on the sheets 112, 114 to define between the weld lines 131, 133 and 141, 143 the channels 130, 140 (see Figure 5). Alternatively, strips 139, 149 for forming the channels 130, 140 may be attached and welded to the inside or outside of the film 1, over the tapes 136, 146 (see Figure 6). Of course, at this step S5 of the method S, the channels are open 130, 140 at their ends 132, 134, 142, 144 to allow the emergence of the ribbons 136, 146.

In a sixth step S6, the first ribbon 136 is welded to the second end 134 of the first channel 130 and the second ribbon 146 is welded to the first end 142 of the second channel 140 using the solder jaws 260.

During a seventh step S7, the film 1 provided with the channels thus closed at one end 134, 142 only is folded back on itself so as to form the first 112 and the second 114 sheet. The first 117 and second 118 edges of the sheets 112, 114 are then welded together by the solder bars 280.

When notches 137, 147 have been formed in step S4 on the film 1, the application of the solder bars 280 on the edges 117, 118 of the sheets 112, 114 has the effect of not welding the ends 132. and 144 channels 130, 140 at the edges 117, 118 respectively, thus leaving the ribbons 136, 146 free to move through these ends 132, 144. In an alternative embodiment, the steps S6 and S7 can be performed simultaneously. For this purpose, the ribbons 136, 146 are welded to the channels 130, 140 at the same time that the sheets 112, 114 are welded together to form the edges 117, 118 of the bag 100. A single welding device is then necessary to perform these two steps S6, S7. The channels 130, 140 may be made, as illustrated in Figure 5, by folding on itself the top of each of the sheets 112, 114 and providing two weld lines 131, 133; 141, 143 of the fold thus formed on the sheets 112, 114 to define between the weld lines 131, 133 and 141, 143 the channels 130, 140. It is also possible, as illustrated in FIG. 6, to add strips 139, 149 on the inside or on the outside of the sheets 112, 114, respectively welded at two parallel lines 131, 133; 141, 143 to define the channels 130, 140 above.

Obviously to allow emergence of ribbons 136, 146, the end of the channels 130, 140 opposite the connection points must be open.

Naturally, the present invention is not limited to the embodiments that have just been described but extends to any variant within its spirit. In particular the configuration of the bags 100 may be subject to many variants known to those skilled in the art. It is thus possible to provide expansion bellows at the bottom 116 and / or side edges 117, 118. These arrangements are known to those skilled in the art and will not be described in more detail later. Moreover, the sheets 112, 114 shown in the appended figures have a rectangular outline. Of course, the invention is not limited to this particular geometry. The welds made on the bags to delimit the channels 130, 140 may be continuous or discontinuous. It can be provided that the strips 136, 146 are engaged inside the channels 130, 140 along their entire length or that they emerge punctually from the channels thanks to discontinuities or windows formed locally in the sheet 112, 114 composing the channels 130, 140. The ribbons 136, 146 may be single-material or multi-material, for example bimaterial.

According to another variant embodiment, it is possible to provide a sliding agent on the ribbons 136, 146 and / or inside the channels 130, 140 in order to facilitate the sliding of the ribbons 136, 146 in the channels 130, 140. where appropriate, the free ends of the ribbons 136, 146 may be secured together to form a loop. Fixing can be performed using a knot, a clip or a clamp reported on their free ends, or (when the tapes are formed in a heat-sealing material), by welding.

The present invention applies to many types of market, such as for example the field of hygiene and the food industry, without being limiting.

Claims (20)

REVENDICATIONS1. Bag (100) having a first sheet (112) and a second sheet (114) together forming a first edge (117) and a second edge (118) of the bag, and a closure device (120), the closure device comprising a first channel (130) and a second channel (140) extending between the edges (117, 118), the first channel and the second channel each comprising a first end (132, 142) and a second end (134); , 144), and - a first ribbon (136), housed in the first channel (130), and a second ribbon (146), housed in the second channel (140), the first ribbon projecting from the first end (132). ) of the first channel and the second ribbon projecting from the second end (144) of the second channel, the bag (100) being characterized in that the first ribbon (136) is soldered (138) to the first channel (130) in an area adjacent to the second end (134) of said first channel (130) and the second end (146) is soldered (148) to the second channel (140) in an area adjacent to the first end (142) of said second channel (140), the first end (132) of the first channel (130) and the second end (144) of the second channel (140) being adjacent to the first edge (117) of the bag (100). The pouch (100) of claim 1, wherein the first ribbon (136) is welded to the second end (134) of the first channel (130) and the second ribbon (146) is welded to the first end (142). the second channel (140). Bag (100) according to one of claims 1 or 2, wherein the first ribbon (136) and the second ribbon (146) protrude from the first channel 302 103 8 22 (130) and the second channel (140) respectively at the first edge (117) of the bag (100). 4. Bag (100) according to one of claims 1 to 3, wherein the second channel (140) is closer to a mouth (119) of the bag (100) than the first channel (130), so that the first channel and the second channel are offset and do not overlap. 5. Bag (100) according to one of claims 1 to 4, wherein the first and second ribbon (136, 146) are made of a heat-sealable material. 6. Sachet (100) according to claim 5, wherein the heat-sealable material comprises at least one of the following polymers: polypropylene and its copolymers, polyethylene and its copolymers, high density polyethylene, low density polyethylene. The bag (100) according to one of the claims 6, wherein the sheets (112, 114) comprise an inner face (113) formed of a heat-sealable material, and wherein the material constituting the first and second ribbons ( 136, 146) is identical to the material constituting the inner layer. 8. Bag (100) according to one of claims 1 to 4, in the first 25 and the second ribbon (136, 146) are made of a non-weldable material. The bag (100) of claim 8, wherein the first and second strips (136, 146) are made of cotton or polyester. 30 Bag (100) according to one of claims 1 to 9, wherein the first channel (130) and the second channel (140) are adjacent to a mouth (119) of the bag (100), or extend to a distance at least two centimeters, preferably at least three centimeters, from a mouth (119) of the bag (100). 11. Bag (100) according to one of claims 1 to 10, wherein the free ends of the ribbons (136, 146) are fixed together to form a loop. Bag (100) according to one of claims 1 to 11, wherein the first and second ribbons (136, 146) have a contact surface respectively with the first and second channels (130, 140) defined to improve taking the solder (138, 148) of the first and second channels (130, 140) on the first and second ribbons (136, 146) respectively. 13. A method of manufacturing (S) a bag (100) according to one of claims 1 to 12, comprising the steps of: bringing (51) a film (1) on a forming machine, bring (S2) a first (136) and a second (146) ribbon on the film (1), - forming (S5) a first (130) and a second (140) channel on the film (1), - folding (S7) the film ( 1) on itself to form the first (112) and second (114) sheets of the bag (100), - soldering (S7) the first sheet (112) onto the second sheet (114), so as to forming a first edge (117) and a second edge (118) of the bag (100), the first sheet (112) and the second sheet (114) respectively comprising the first channel (130) and the second channel (140); extending between the edges (117,118), the first channel (130) and the second channel (140) each having a first end (132,142) and a second end (134,144), the method (S) being characterized in that the first ru ban (136) is soldered (138) to the first channel (130) in an area adjacent to the second end (134) of said first channel (130), and the second band 302 103 8 24 (146) is secured by welding (148) to the second channel (140), in an area adjacent to the first end (142) of said second channel (140) (S6), the first end (132) of the first channel (130) and the second end (144) ) of the second channel (140) being adjacent to the first edge (117) of the bag (100). The manufacturing method (S) according to claim 13, wherein the first channel (130) and the second channel (140) are positioned offset on the first sheet (112) and the second sheet (114) respectively. . 15. The manufacturing method (S) according to one of claims 13 or 14, further comprising a step (S3) during which notches (137, 147) are formed in the film (1) in an area corresponding to the first end (132) of the first channel (130) and the second end (144) of the second channel (140), so that in step (S7) of welding the first edge (117) and the second edge (118) of the bag (100), the first (136) and second (146) ribbons are not welded to the first edge (117) of the bag (100). 20 16. Manufacturing method (S) according to one of claims 13 to 15, wherein the first channel (130) and the second channel (140) are formed by folding on itself a top of the sheets (112, 114) at the mouth (119) or by welding (138, 148) of a band (139, 149) attached to the sheets (112, 114) of the bag (100). 17. Manufacturing method (S) according to one of claims 13 to 16, wherein the step (S6) of welding the first and second ribbons (136, 146) to the first and second channels (130, 140) and the solder step (S7) of the first sheet (112) on the second sheet (114) are performed simultaneously. 18. Machine (200) for the manufacture of a bag (100) according to one of claims 1 to 12, comprising: - a device (210) configured to bring a film (1) to a forming machine, - a device (230) configured to feed a first (136) and a second (146) ribbon (146) to the film (1), - a device (270) configured to fold the film (1) on itself so as to forming the sheets (112, 114) of the bag (100), - solder bars (280) configured to weld the first sheet (112) to the second sheet (114) to form a first edge (117) and a second edge (118) of the bag (100), the first sheet (112) and the second sheet (114) respectively comprising a first channel (130) and a second channel (140) extending between the first edge (117). ) and the second edge (118), the first channel (130) and the second channel (140) each having a first end (132, 142) and a second end (134, 144), the wherein (200) is characterized in that it further comprises solder jaws (260) configured to weld the first band (136) to the first channel (130) in an area adjacent to the second end (134) of said first channel (130). channel (130), and the second ribbon (146) at the second channel (140), in an area adjacent to the first end (142) of said second channel (140), the first end (132) of the first channel (130) and the second end (144) of the second channel (140) being adjacent to the first edge (117) of the bag (100). The machine (200) of claim 18, further comprising a device (215) configured to form notches (137, 147) on the film (1), in a region of the film (1) for receiving the first end (132) of the first channel (130) and the second end (144) of the second channel (140). 20. Machine (200) according to claim 19, wherein the welding bars (280) have, in a welding face (282), a notch (284) configured to come opposite the first end (132) of the first channel (130) and the second end (144) of the second channel (140).