FR3021039A1 - 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 welded respectively to the first and second channels (130, 140) 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 first edge and the second edge, 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 (146) 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; and the second ribbon is soldered to the second channel.

Some preferred but non-limiting characteristics of the bag are the following: the first ribbon is welded in an area adjacent to the second end of the first channel and the second ribbon is welded in an area adjacent to the first end of the second channel; 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 end of the first channel and the first end of the second channel are adjacent to the first edge of the bag, - the first end. of the first channel and the second end of the second channel are adjacent to the first edge of the bag, - the first ribbon and the second ribbon project from the first channel and the second channel, respectively, at the edges of the bag, - the first ribbon is welded into a first zone extending away from the second end of the first channel and the second the ribbon 30 is welded in a second zone extending at a distance from the first end of the second channel the first ribbon further projecting from the second end of the first channel and the second ribbon further projecting from the first end of the second channel the first zone extends in the central part of the first sheet and the second zone extends in the central part of the second sheet; the second channel is closer to a mouth of the bag than the first channel; that the first channel and the second channel are staggered and do not overlap, - the first ribbon and the second ribbon comprise a heat-sealable material, - the heat-sealable material comprises a polyolefin polymer or copolymer, - the heat-sealable material comprises: at least one of the following polymers: polypropylene and its copolymers, polyethylene and its copolymers, high density polyethylene, polyethylene bass density, the first sheet and the second sheet comprise an inner face formed in a heat-sealable material, and the material constituting the first and second ribbons is identical to the material constituting the inner face of the sheets, the first ribbon and the second ribbon; ribbon comprises a non-fuse material, the non-fuse material comprises cotton or polyester, the channels are adjacent to a mouth of the bag or extend at a distance of at least two centimeters, preferably at least three centimeters, a mouth of the bag, and - wherein the first and second ribbons have a contact surface respectively with the first and second channels defined to improve the grip of the first and second channels on the first and second ribbons; respectively. According to a second aspect, the invention also proposes a method for manufacturing a bag as described above, comprising the following steps: bringing a film to a forming machine, bringing a first and a second ribbon onto 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 sheets 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; characterized in that the first tape is soldered to the first channel and the second tape is soldered to the second channel. Some preferred but non-limiting 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 first ribbon and the second ribbon comprise a material heat-sealable, the method further comprising a step in which notches are formed in the film at the first end of the first channel and the second end of the second channel, so that during the soldering step from the first sheet on the second sheet to form the first edge and the second edge of the bag the first and second ribbons are not welded to the edges of the bag, the first ribbon and the second ribbon comprise a heat-sealable material, the first ribbon being welded at the second end of the first channel and the second ribbon attached by welding at the first end of the second channel by means of welding jaws having, in a welding face, a notch configured to face the first end of the first channel and the second end of the second channel the step of welding the first and second ribbons to the first and second channels and the step of welding the first sheet to the second sheet are carried out simultaneously, and the first channel and the second channel are formed by folding on it; -Even of a top of the leaves at the mouth or by welding a band reported on the sheets of the bag.

According to a third aspect, the invention also proposes a machine for the manufacture of a bag as described above, comprising: - a device configured to bring a film to a forming machine, - a device configured to bring a first and a second ribbon 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 to 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 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 first nal and the second ribbon to the second channel. Some preferred but non-limiting features of the machine are the following: the welding jaws are configured to weld the first ribbon in an area adjacent to the second end of the first channel and the second ribbon in an area adjacent to the first end of the second ribbon channel, - the machine further comprises a device configured to form notches on the film, in an area of the film for receiving the first end of the first channel and the second end of the second channel, - the welding jaws and / or the solder bars have, in a welding face, a notch configured to face the first end of the first channel and the second end of the second channel, the solder jaws have a solder face, said solder face having a convex cross-section in order to apply a pressure gradient and temperature to the first ban and second ribbon when soldering to the first and second channels, respectively. - A convexity of the cross section of the weld face is configured so that the pressure gradient and temperature gradually decreases within the welds in the direction of at least one boundary of said welds.

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. 3 represents an external perspective view of a bag according to a first embodiment of the present invention; FIG. 4 represents an external perspective view of a bag according to an alternative embodiment of the first embodiment of the present invention; - Figures 5 and 6 show cross-sectional views of two embodiments of a pouch of the embodiment shown in Figure 4; - Figure 7 shows an external perspective view of the bag of Figure 3, in the closed position; FIG. 8 represents an external perspective view of a second variant embodiment of a bag according to the first embodiment of the present invention; Fig. 9 is an outer perspective view of a pouch according to a second embodiment of the present invention; - Figure 10a is a longitudinal sectional view of an embodiment of welding jaws that can be used for the manufacture of a bag according to the invention, said welding jaws being in position to weld the end of the channels on the corresponding leaves; Fig. 10b is a cross-sectional view of the solder jaws of Fig. 10a, in position to weld the ends of the channels to the corresponding sheets; - Figure 11a shows a detailed schematic view of the weld of the first ribbon on the second end of the first channel of the bag of Figure 4; FIG. 11b is a diagrammatic detail view of a second welding example according to the first embodiment of the invention of the first ribbon on the second end of the first channel of a bag; FIG. 12 is a schematic representation of an exemplary embodiment of a machine for manufacturing a bag according to the invention; and FIG. 13 is a flowchart representing various steps of an exemplary embodiment of the method of manufacturing a bag according to the invention. DETAILED DESCRIPTION OF AN EMBODIMENT The pouches according to the present invention may be the subject of numerous variants which will not all be described in detail hereinafter. 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 1 on itself, for example at an edge corresponding to its bottom 116 then ensuring the welding of the two sheets 112, 114 carried adjacent to the edges 117, 118. One can also ensure the folding of the film 1 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 1 is a material heat sealable, especially 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 1 in the composite material comprises an inner face 113 formed in a heat-sealable material, in particular 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 projecting from the second end 144 of the second channel 140. In addition, the first ribbon 136 is welded to the first channel 130 and the second ribbon 146 is welded to the second channel 140. It will be understood that the welding of the ribbons 136 , 146 to their respective channel 130, 140 makes it possible to block the ribbons 136, 146 in the channels 130, 140 without the need to form a node at their free end. Furthermore, the fixing of the ribbons 136, 146 to the channels 130, 140 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 method of manufacturing the bags 100 is thus greatly simplified, which allows to multiply by two or three their production rate. 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 7, 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 fixed on the first sheet 112 while the second channel 140 is fixed on the second sheet 114, in order to improve the closure of the bag 100. According to a first embodiment (see FIGS. 3 to 7) the first ribbon 130 is welded in an area adjacent to the second end 134 of the first channel 130 and the second ribbon 146 is welded in an area adjacent to the first end 142 of the second channel 140. The ribbons 136, 146 can then be welded either directly at the free ends 132, 144 respectively (see Figure 11a) or at a short distance from these free ends 132, 144 (see Figure 11b). According to a first variant embodiment, illustrated in FIGS. 3 and 4, the first end 132 of the first channel 130 and the first end 142 of the second channel 140 may be adjacent to the first edge 117 of the bag 100. Thus, in this first variant embodiment 3 to 6), the first ribbon 136 and the second ribbon 146 protrude from their respective channel 130, 140 at an opposite edge 117, 118 of the bag 100. The closure of the bag 100 therefore takes place pulling on the ribbons 136, 146 in the extension of their channel 130, 140 respectively, in opposite directions. Those skilled in the art will understand that, by pulling on the emergent ends of each of the ribbons 136, 146 as illustrated in FIG. 3 by the arrows referenced C and D, the closure of the mouthpiece 119 is easily obtained as illustrated on FIG. Figure 7.

To reverse the opening of a bag simply loosen the mouth 119 to obtain the opening of the mouth by reverse sliding ribbons 136, 146 in the channels 130, 140. In a second embodiment, illustrated in FIG. 8, 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, in this second embodiment, the first band 136 and the second band 146 protrude from their respective channel 130, 140 at the same edge 117 of the bag 100. The closure of the bag 100 is therefore done by pulling on the ribbons 136, 146 in the extension of their respective channel 130, 140, in the same sense, by grasping the first edge 117 of the bag at which the ribbons 136, 146. project. In a second embodiment, illustrated in Figure 9, the first ribbon 136 is welded to the channel 130 in a first z one 151 extending away from the second end 134 of the first channel 130 and the second ribbon 146 is welded to the channel 140 in a second zone 152 extending away from the first end 142 of the second channel 140. For example, the first zone 151 and the second zone 152 may extend in a central portion of the first sheet 112 and the second sheet 114, respectively. On the other hand, the first zone 151 and the second zone 152 may be superimposed or offset with respect to one another along the channels 130, 140.

In this embodiment, the first band 136 also projects from the second end 134 of the first channel 103 while the second band 146 also projects from the first end 142 of the second channel 140.

The closure of a bag 100 according to the second embodiment is therefore seizing the bag 100 in the first and the second zone 151, 152, at the level of the fixing of the ribbons 136, 146, and pulling on the ends free ribbons 136, 146 (or simultaneously, at a first edge 117 of the bag 100 and at the second edge 118 of the bag 100). This closure is particularly easy insofar as the distance to be traveled by the edges 117, 118 to reach the closed configuration of the bag 100 is reduced (by half when the zones 151 and 152 are in the middle of the channels 130, 140). reduces both the time required to close the bag 100 and the friction associated with the pleating of the sheets 112, 114. The opening can also be done by pulling on the edges 117, 118 of the bag 100, or by holding in hands the first 151 and the second 152 area and pulling on the first 117 and the second 118 edge of the bag 100. Here again, the opening is simplified by the separation of the channels 130, 140 in two parts by the weld in the first 151 and the second zone 152. Whatever the embodiment, the first channel 130 and the second channel 140 may be offset relative to one another according to the height of the bag 100 (see FIG. to say that the second me channel 140 may be closer to the mouth 119 of the bag 100 that the first channel 130, so 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 closing the bag 100 by pulling on the ribbons 136, 146 in opposite directions, to deform the channels 130, 140 and thus the mouth 119 by bringing the first channel closer together. 130 and the second channel 140. This deformation has the effect of increasing the folding of the sheets 112, 114 and thus improve the sealing of the bag 100.

Alternatively, the first channel 130 and the second channel 140 may on the contrary be superimposed and not be offset relative to each other according to the height of the bag 100.

As indicated above, the ends of the first ribbon 136 and the second ribbon 146 are fixed to the corresponding channel 130, 140 by welding, as referenced at 138, 148 in FIGS. 3, 4, 11a and 11b. The weld 138, 148 of the ribbons 136, 146 to the channels 130, 140 has the advantage of greatly accelerating the rate of manufacture of the bags 100. The weld 138, 148 can indeed be carried out very quickly, using means Conventional in the field of sachets. 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 edge 118, 117 of the bag 100. Alternatively, the weld can also be obtained by multiple welding or wire. In a first embodiment, the ribbon 136, 146 may be made of a heat-sealable material, typically a polyolefin comprising a polymer or a copolymer among the following materials: polypropylene and its copolymers, polyethylene and its copolymers, high density polyethylene, low polyethylene density. In this way, during the welding of the end of the ribbon 136, 146 to the channel 130, 140, the end of the ribbon 136, 146 melts and forms a solid junction with the channel 130, 140 of the bag 100. To allow welding 138, 148 of the ends of the ribbons 136, 146 on the bag 100, the ribbons 136, 146 may 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 inner layer) and the ribbons 136, 146 may in particular 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.

This embodiment has the advantage of making it possible to obtain single-material sachets 100, which widens the field of use of the sachets 100, while at the same time greatly increasing the rate of manufacture of the sachets.

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, enables the bag to be recycled.

In a second embodiment, the ribbon 136, 146 may be made of a non-fusible material (ie not heat-sealable) at the soldering temperatures on the bag material, typically cotton or polyester. The Applicant has indeed noticed that it is not necessary for the strips 136, 146 to melt locally at the weld to fix them to the bag 100. The welding, for example with ultrasound, makes it possible to imprison mechanically ribbons 136, 146 in their respective channel 130, 140. The weld 138, 148 of the ends of the first ribbon 136 and the second ribbon 146 on their corresponding channel 130, 140 produces a shearing effect of the ends of the ribbons 136, 146, thus making it possible to form connection points between the bag 100 and ribbons 136, 146. This embodiment has the advantage of making it possible to increase very considerably the rate of manufacture of the bags, avoiding the creation of nodes at the ends of the ribbons 136, 146. The quantity of material The need for ribbons 136, 146 may be further reduced in comparison with knotted ribbon bags.

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, it is for example it is 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 grip of the weld 138, 148 on the ribbon 136, 146. In particular, a ribbon 136, 146 The shape of a strip will have a larger contact area than a generally cylindrical strip 136, 146, and thus the grip of the weld 138, 148 on the strip 136, 146 will be improved. Bag production machine 200 The bags 100 can then be obtained using a machine 200 comprising: a device 210 configured to bring a film 1 onto a forming machine; a device 220 configured to cut the film; a device 230 configured to bring a first and a second ribbon 136, 146 onto the film 1, optionally an apparatus 240 for forming the first channel 130 and the second channel 140 on the film 1 (or alternatively 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 soldering the first ribbon 136 to the first channel 130 and the second ribbon 146 to the second channel 140, the first end 132 of the first channel 130 and the first end 142 of the second channel 140 being adjacent to the first edge 117 of the bag The machine 200 may further comprise a device 270 for folding the film 1 to form the first 112 and the second sheet 114, as well as solder bars 280 for welding the first sheet 112 to the second sheet 114, in order to form the first edge 117 and the second edge 118 of the bag 100. The solder bars 280 may in particular comprise ultrasonic electrodes.

In the case where the tapes are formed in a heat-sealable material, according to the first embodiment described above, the machine 200 may further comprise a device 215 configured to form notches 137, 147 (or clearances) on the film 1 in the region of the film 1 intended to receive 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 strips 136, 146 on the film 1 during the step S7 welding the edges 117, 118 of the bag 100. The embodiment of the notches 137, 147 in the film 1 makes it possible to remove the material at the ends 132, 144 to remain free of the channels 130 , 140, so that when welding the edges 117, 118 of the bag 100 by the solder 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 or co uper the ends 132, 144 of the ribbons 136, 146, thus ensuring that the ribbons 136, 146 remain free of movement at these ends 132, 144. In particular, in the case of the embodiment of a bag 100 according to the In a second embodiment, the device 215 may be configured to form notches 137, 147 on the film 1, in the region of the film 1 for receiving the ends 132, 134, 142, 144 of the channels 130, 140. Thus, when welding the edges 117, 118 of the bag 100 by the solder bars 280, the ribbons 136, 146 are ensured to remain free of movement at each of the ends 132, 134, 142, 144 of the channels 130, 140. When the machine 200 comprises a device 215 configured to form notches 137, 147 on the film 1, the welding bars 280 may further have, in a welding face, a notch configured to come opposite the notches 137, 147. It will be understood indeed that, the ribbons 136, 146 being formed in a heat-sealable material, it is preferable to prevent their projecting portions of the channels 130, 140 at the notches 137, 147 from being cut by the solder bars 280, when the latter weld the first sheet 112 onto the second sheet 114, so as to form the first edge 117 and the second edge 118 of the bag 100. Where appropriate, the notches 137, 147 also make it possible to use strips 136, 146 having a length equal to the width ( edge 117 on board 118) of the bag 100, while ensuring a good handling of said ribbons 136, 146 to close the bag 100. Optionally, the welding of the ribbons 136, 146 can be performed simultaneously. For this, and especially in the case of the production of a bag 100 according to the first embodiment, the welding jaws 260 may have, in a welding face 262, a notch 264 configured to come opposite the first end 132 of the first channel 130 and the second end 144 of the second channel 140, in order to weld only the second end 134 of the first channel 130 and the first end 142 of the second channel 140 (see Figure 10a). It will be understood that, since the ribbons 136, 146 are formed in a heat-sealable material, it is preferable to prevent their parts which project from the channels 130, 140 from coming into direct contact with the welding jaws 260. These jaws 260 are particularly suitable when the first and second channels 130, 140 are offset. A single welding step is then necessary to fix the ribbons 136, 146 in the channels 130, 140. This gives a bag 100 whose channels 130, 140 are offset. This variant embodiment is particularly advantageous insofar as it makes it possible to weld ribbons 136, 146 in a reliable and fast manner to the bag 100. Alternatively, the solder jaws 260 may be conventional and furthermore comprise a configured counter-element. to be placed between the sheets 112, 114 during the welding of the ribbons 136, 146 in their respective channel 130, 140, in order to prevent the welding of the ribbons 136, 146 to the first channel 130 and the second channel 140 from causing the welding the portion facing the second channel 140 or the first channel 130, respectively. In this case, the channels 130, 140 may be shifted as well as aligned (that is to say superimposed).

Note that when the ribbons 136, 146 are formed in a non-fuse material, in particular cotton or polyester, the notches 137, 147 and the notches 264 (on the welding jaws 260 and the welding bars 280) are optional. . Indeed, such ribbons 136, 146 are not likely to melt or be cut during the application of these welding means 280 and 260. It is therefore not necessary to adapt the sizing of the welding means to the size of the ribbons 136, 146 chosen, no notching being necessary.

When the first ribbon 130 is welded in an area adjacent to the second end 134 of the first channel 130 and the second ribbon 146 is welded into an area adjacent to the first end 142 of the second channel 140, the step of attaching the ribbons 136 , 146 and the soldering step of the edges of the bag 100 can therefore be performed simultaneously using conventional welding means (ultrasound, etc.). This embodiment thus makes it possible to accelerate the manufacture of the bags 100 even more, and to reduce their cost of production. The Applicant has found that the welding of the ribbons 136, 146 to the corresponding channels 130, 140 can weaken the bag 100 by forming a break in continuity at the limits 138a, 148a of the weld 138, 148. Indeed, at the of these limits 138a, 148a of the welds 138, 148, the ribbons 136, 138 and the film 1 forming the bag 100 are weakened by the welds 138, 148 which create a preferred line of rupture in case of significant effort applied to the bag 100 (either on the ribbons 136, 146 or on the sheets 112, 114, by a user or the contents of the bag 100). The solder face 262 of the solder jaws 260 may therefore be configured to suppress, or at least reduce, that break line. For this, as illustrated in FIG. 10b, the welding face 262 may have a convex cross-section, configured to apply a pressure and temperature gradient on the film 1 during the welding of the first 136 and second 146 ribbon on the first 130 and second 140 channels. By cross section, here will be understood the section of the welding jaws 260 which is perpendicular to the welding plane of the jaws 260. In practice, in the case of the welding of the strips 136, 146 at the edges 117, 118 of the bag 100 the radius of curvature of the convex cross-section is chosen so that the portion of the welding jaws 260 configured to face and form the outer limit 138b, 148b of the welds 138, 148 (at the edges 117, 118) is closer to the weld than the portion of the welding jaws 260 configured to face and weld the inner limit 138a, 148a of the welds 138, 148 (at the sheets 112, 114). In this way, the temperature and pressure applied by the solder jaws 260 progressively reduce the outer limit 138b, 148b of the welds 138, 148 (ie at the ends 134, 142 of the channels 130, 140) towards the internal limit. 138a, 148a welds 138, 148 (or towards the center of the sheets 112, 114 of the bag 100). In the case of a weld 138, 148 made at a distance from the edges 117, 118 of the bag 100, two discontinuities of continuity are formed on either side of the weld 138, 148: the convex cross-section of the welding jaws 260 is therefore adapted to reduce these two lines of rupture. In practice, the radius of curvature of the convex cross section is chosen so that the portion of the welding jaws 260 configured to face and form a central portion 25 of the welds 138, 148 is closer to the weld than the portion welding jaws 260 configured to face and weld the outer boundaries of the welds 138, 148. With this convexly shaped cross section, the welding jaws 260 are capable of applying a progressively decreasing pressure and temperature. The residual stresses in the film 1 and the ribbons 136, 146 therefore also decrease continuously, thus reducing (or even eliminating) the rupture line present at the boundaries of the welds 138, 148.

Of course, the specific shape of the welding jaws 260 described above, and in particular the convex-shaped cross section of the welding face 262 of these jaws 260, can be used in other applications than the manufacture of bags 100. with ribbons 136, 146 according to the invention. For example, this specific form of welding jaws 260 equipped with the convex weld surface 262 can be used to weld any type of strip (support sails of a conventional closure device - whether with complementary male / female profiles or male / male, velvet-hook type, etc. -) on a film. This form of weld surface makes it possible to reduce or even eliminate the preferential rupture lines at the boundaries of the weld 138, 148.

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. In a third optional step S3, notches 137, 147 may be formed on the film 1, in the region of the film intended for receiving the ends 132, 134, 142, 144 of the channels 130, 140. In a fourth step S4, the film 1 is cut, if necessary 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 the free ends of the ribbons 136, 146 .

During a fifth step S5, the sides of the film 1 are folded back on themselves so as to form the first 130 and second 140 channels, so that the channels 130, 140 extend parallel to the direction of movement of the 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 method S, the channels are open 130, 140 at their ends 132, 134, 142, 144 to allow the emergence of ribbons 136, 146. During a sixth step S6 the first ribbon 136 is welded to the first channel 130 and the second ribbon 146 is welded to the second channel 140 by means of welding jaws 260. The solder jaws 260 may be conventional or include notches 264. During a seventh step S7, the film 1 provided with ribbons 136, 146 and welded in their respective channel 130, 140 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 during step S4 on the film 1, or when the ribbons 136, 146 are formed in a non-fuse material, 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, 134, 142, 144 of the channels 130, 140 at the edges 117, 118 respectively, thus leaving the ribbons 136, 146 free of movement through these ends 132, 134, 142, 144. In an alternative embodiment, when the first ribbon 130 is welded into an area adjacent to the second end 134 of the first channel 130 and that the second ribbon 146 is welded in an area adjacent to the first end 142 of the second channel 140, 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 260 or 280 is then necessary to perform these two steps S6, S7. 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 100 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, a sliding agent may be provided 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.

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 (29)

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 (100), and a closure device (120), the device closure device (120) 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), and a first ribbon (136), housed in the first channel (130), and a second ribbon (146), housed in the second channel (140), the first band (136) projecting from 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 bag (100) being characterized in that the first ribbon (136) is welded (138) to the first channel (130) and the second ribbon (146) is fixed by welding (148) the second channel (140). 20 The pouch (100) of claim 1, wherein the first ribbon (136) is welded into an area adjacent to the second end (134) of the first channel (130) and the second ribbon (146) is welded into an area. adjacent the first end (142) of the second channel (140). The pouch (100) of claim 2, 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). 25 30 4. Bag (100) according to one of claims 2 or 3, wherein the first end (132) of the first channel (130) and the first end (142) of the second channel (140) are adjacent to the first edge (117). ) of the bag (100). 5. Bag (100) according to one of claims 2 or 3, wherein 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). Bag (100) according to one of claims 2 to 5, wherein the first ribbon (136) and the second ribbon (146) protrude from the first channel (130) and the second channel (140), respectively, to the level of the edges (117, 118) of the bag (100). The pouch (100) of claim 1, wherein the first ribbon (136) is welded into a first zone (151) extending away from the second end (134) of the first channel (130) and the second ribbon (146) is welded into a second zone (152) extending away from the first end (142) of the second channel (140), the first ribbon (136) further projecting from the second end (134) of the first channel (130) and the second ribbon (146) further projecting from the first end (142) of the second channel (140). Bag (100) according to claim 7, wherein the first zone (151) extends in the central part of the first sheet (112) and the second zone (152) extends in the central part of the second sheet ( 114). 9. Bag (100) according to one of claims 1 to 8, 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 (130) and the second channel (140) are offset and do not overlap. The bag (100) according to one of claims 1 to 9, wherein the first ribbon (136) and the second ribbon (146) comprise a heat-sealable material. The pouch (100) of claim 10, wherein the heat sealable material comprises a polyolefin polymer or copolymer. The pouch (100) according to claim 11, wherein the heat sealable material comprises at least one of the following polymers: polypropylene and its copolymers, polyethylene and copolymers thereof, high density polyethylene, low density polyethylene. The bag according to one of claims 10 to 12, wherein the first sheet (112) and the second sheet (114) comprise an inner face (113) formed of a heat-sealable material, and the material constituting the first (136). ) and second (146) ribbons is identical to the material constituting the inner face (113) of the sheets (112, 114). 14. Bag (100) according to one of claims 1 to 9, wherein - the first ribbon (136) and the second ribbon (146) comprise a non-fuse material. The bag (100) of claim 14, wherein the non-fusible material comprises cotton or polyester. 25 16. Bag (100) according to one of claims 1 to 15, wherein the channels are adjacent to a mouth (119) of the bag (100) or extend at a distance at least equal to two centimeters, preferably at minus three centimeters, from a mouth (119) of the bag (100). Bag (100) according to one of claims 1 to 16, wherein the first and second ribbons (136, 146) have a contact surface respectively with the first and second channels (130, 140) defined to Improving the seam engagement (138, 148) of the first and second channels (130, 140) on the first and second ribbons (136, 146) respectively. 18. A method of manufacturing (S) a bag (100) according to one of claims 1 to 17, 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), - to weld (S7) the first sheet (112) onto 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 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 ribbon (136) is welded (138) to the first channel (130) and the second ribbon (146) is soldered (148) to the second channel (140) (S6). The manufacturing method (S) according to claim 18, wherein the first channel (130) and the second channel (140) are positioned offset on the first sheet (112) and the second sheet (114), respectively. 20. Manufacturing method (S) according to one of claims 18 or 19, wherein the first ribbon (136) and the second ribbon (146) comprise a heat-sealable material, the method further comprising step (S3) in the course of which notches (137, 147) are formed in the film (1) at 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 sheet (112) on the second sheet (114) to form the first edge (117) and the second edge (118) of the bag (100), the first (136) and the second (146) ribbons are not welded to the edges (117, 118) of the bag (100). 21. Manufacturing method (S) according to one of claims 18 to 20, wherein the first ribbon (136) and the second ribbon (146) comprise a heat-sealable material, the first ribbon (136) being fixed by welding (138). ) at the second end (134) of the first channel (130) and the second strip (146) being welded (148) at the first end (142) of the second channel (140) (S6) to the first using welding jaws (260) having, in a welding face (262), a notch (264) configured to face the first end (132) of the first channel (130) and the second end (144) ) of the second channel (140). 22. Manufacturing method (S) according to one of claims 18 to 21, wherein the step (S6) of welding the first and second ribbons (136, 146) to the first and second channels (130, 140) and the soldering step (S7) of the first sheet (112) on the second sheet (114) are performed simultaneously. 23. Manufacturing method (S) according to one of claims 18 to 22, 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 a band (139, 149) attached to the sheets (112, 114) of the bag (100). 24. Machine (200) for the manufacture of a bag (100) according to one of claims 1 to 17, 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 of the bag (100), - solder bars (280), configured to weld the first sheet (112) on the second sheet (114), so as 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 machine (200) characterized in that it further comprises solder jaws (260) configured to weld the first ribbon (136) to the first channel (130) and the second ribbon (146) to the second channel (140). The machine (200) of claim 24, wherein the solder jaws (260) are configured to weld the first ribbon (136) in an area adjacent to the second end (134) of the first channel (130) and the second end (134) ribbon (146) in an area adjacent the first end (142) of the second channel (140). The machine (200) of claim 25, 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). 27. Machine (200) according to one of claims 24 to 26, wherein the welding jaws (260) and / or the welding bars (280) have, in a welding face (262), a notch (264). ) configured to face the first end (132) of the first channel (130) and the second end (144) of the second channel (140). 28. Machine (200) according to one of claims 24 to 27, wherein the welding jaws (260) have a welding face (262), said welding face (262) having a convex cross-section to apply a pressure and temperature gradient at the first ribbon (136) and second ribbon (146) when soldered to the first channel (130) and the second channel (140), respectively. The machine (200) of claim 28, wherein a convexity of the cross section of the weld face (262) is configured such that the pressure and temperature gradient gradually decreases within the welds (138, 148). in the direction of at least one boundary (138a, 148a) of said welds (138, 148).