FR2777498A1 - Manufacturing procedure for forming sachets - Google Patents

Abstract

The procedure for manufacturing a film (50) intended to form sachets consists of moving the film and fixing sequentially on it and transverse to its displacement direction (D) a closing device (1). This device includes a first band (2) supporting a male closing section (10) engaging another complementary female closing section supported by a second band (4). Each band comprises a thin transparent section (6,8) extending laterally on one side of the sections supported by each band.

Description

The present invention relates to the field of training machines,

  automatic filling and closing of packages, comprising closing devices, for example with male profiles and

complementary female.

  Such machines are often called FFS, corresponding

  with the initials of the English expression "Form, Fill and Seal machines".

  Document US 4,909,017 describes a process during which sachets are provided with a closure device, during their formation on an FFS machine. The bags are formed from a film of thermoplastic material. The film is in the form of a strip of material extending between two free longitudinal edges with reference to its displacement. This film is unwound upstream of a filling chute. The closing device is arranged on the film, also upstream of the chute, transversely with respect to the direction of movement of the film. The closing device is made up of two strips provided with complementary profiles. A first strip of the closure device is welded to the film upstream of the chute, on a part of the film intended to form a first wall of a bag. The sachet is then formed into

  wrapping the chute and welding the two longitudinal edges of the film.

  The second closure strip is then welded downstream of the chute

on a second bag wall.

  Document US 4,655,862 also describes a process for forming resealable bags, on FFS machines, during which sachets are provided with a closure device which is arranged perpendicular to the direction of formation of these bags. This closing device is deposited upstream of the filling spout, on a film in the form of a single strip. This strip comprises at least one folding zone transverse to the strip, so that the strip can be folded back on itself and facing each other, regions of the strip capable of cooperating together to ensure

closing the bag.

  The Applicant wished that the steps of maintaining, welding and fitting the closure device on the film be easier to

  realize that that of the processes described in the aforementioned documents.

  This object is achieved by a method of manufacturing a film intended to form sachets, comprising a step consisting in moving the film and in sequentially fixing on the film and transversely with reference to the direction of movement thereof, a closing device comprising a first strip supporting at least one closing profile engaged with another closing profile which is complementary thereto and supported by a second strip, or part of the first strip, which will be fixed to the film subsequently, characterized in that each strip comprises at least one veil extending widely laterally on one side of the one or more

  profiles supported by each strip.

  Such sails give the invention a number of advantages.

  Thanks to its larger cross-sectional area, a device for implementing the method according to the invention is easily worn and positioned. In addition, the sails can be set at temperatures

  low enough to avoid damaging the profiles.

  They also allow the step of fixing the closure device to the film to be carried out by welding the film with at least one zone of these webs different from that located under the profiles, which also makes it possible to avoid

  damage the profiles during this welding.

  Other aspects, aims and advantages of the invention will become apparent on

  reading of the detailed description which follows. The invention will also be better

  understood with reference to the accompanying drawings in which: - Figure 1 shows schematically, in cross section three examples of devices for implementing the method according to the invention; - Figure 2 shows schematically a perspective view of a closure device and of the welding means of this device on a film intended to form sachets by the method according to the invention; - Figure 3 shows schematically a perspective view of first and second means for welding a closure device, located respectively upstream and downstream, of a filling tube of a bag forming machine according to invention; - Figure 4 is a side elevational view of the second welding means of a closure device, of a bag forming machine according to the invention; - Figure 5 is a longitudinal section of the filling spout and the second welding means of the closure device, according to the plane V.V, of the bag-forming machine according to the invention, shown in Figure 4; - Figure 6 is a cross section of an example of a closure device for implementing the method according to the invention; - Figure 7 shows schematically, in cross section relative to the length of the closure device shown in Figure 6, second welding means and cutting means, of a bag forming machine according to the invention; - Figure 8 shows schematically a cross section of another example of a closure device for implementing the method according to the invention; - Figure 9 shows schematically, in cross section, relative to the length of the closure device shown in Figure 8, second welding means and cutting means of a bag forming machine according to the invention; - Figure 10 shows a schematic cross section of another example of a closure device for implementing the method according to the invention; - Figure 11 shows schematically, in cross section, another example of a closure device for implementing the method according to the invention; - Figure 12 schematically shows a front elevation view of a bag provided with another example of a closure device for implementing the method according to the invention; - Figure 13 shows schematically, in cross section, another example of the closure device for implementing the method according to the invention; - Figure 14 shows schematically, in cross section, the device shown in Figure 13 in closed configuration; - Figure 15 shows schematically, in cross section, another variant of the closure device for implementing the method according to the invention; - Figure 16 shows schematically, in cross section, the top of a bag provided with another variant of a closure device for implementing the method according to the invention; - Figure 17 shows schematically, in cross section, another variant of a closure device for implementing the method according to the invention; - Figure 18 shows schematically, in cross section, the closure device shown in Figure 17 in the closed configuration; FIG. 19 schematically represents, in cross section, another variant of a closure device for implementing the method according to the invention; - Figure 20 shows schematically, in cross section, the closure device shown in Figure 19, in the closed configuration; - Figure 21 shows schematically, in cross section, a variant of the fixing of a closure device on a film, by the

method according to the invention.

  In Figure 1, three closing devices 1 are shown for implementing the method according to the invention. These devices 1 comprise two strips 2, 4. Each strip 2, 4 comprises webs 6, 8 and sections 10, 12. The sections 10, 12 extend longitudinally on the strips 2, 4. The sections 10, 12 have forms capable of cooperating with each other in a complementary manner. For example, one of the profiles, known as the male profile, has a cross-sectional shape with an arrowhead, it can be inserted and kept in engagement in the profile 12, called the female profile,

throat-shaped.

  Each strip 2, 4 may comprise several sections 10, 12 similar, for example, to those described above. These profiles are then

parallel to each other.

  According to the present invention, the strips 2, 4 respectively comprise a first web 6 and a second web 8 which extend

  widely laterally on one side of the section or sections 10, 12.

  According to certain variants of the invention, this first veil 6 and this second veil 8 can be replaced by a first 6 and a second 8 parts of a single veil making it possible to join the two strips 2,4. The closure devices 1 of FIGS. 1 a and 1 b comprise two complementary sections 10, 12, each supported by one of the two parts 6, 8 of a single web, U-shaped in cross section relative to the longitudinal direction of the sections 10, 12. The sections 10, 12 of the closure device 1 of FIG. 1a are located near the bottom of the throat of the U. The sections 10, 12 of the closure device 1 of FIG. 1b are located near the free ends of the branches of the U. Sails 6, 8 of the

  closure device 1 of Figure 1lc are independent of each other.

  The profiles 10, 12 of the closure device 1 of FIG. 1c are located

  near a free sail 6, 8.

  These devices are particularly suitable for being fixed on the film 50, by the method according to the invention, since the surface of the webs 6, 8 is such that it makes it possible to weld these webs 6, 8 on the film

  on an area of these which is not under the profiles 10, 12.

  This facilitates the installation of the closure device 1 and the welding of

this one on film 50.

  Preferably at least one veil 6, 8 extends laterally over

  an area at least equal in surface to that located under the profiles 10, 12.

  Preferably, the method according to the invention is used for

  form sachets 30 on an FFS 100 machine.

  In this case, during the process according to the invention, the step of fixing the first web 6 to a film 50 is carried out upstream of a filling chute 130 of the FFS machine 100. In FIG. 2, is shown a portion of the film 50 intended to form sachets 30. The film moves in the direction of the chute 130 in the direction indicated by the arrow D. The film 50 has two free longitudinal edges 52, 54, parallel

to its direction of travel.

  Crosswise with respect to the direction of movement of the film, a closing device 1 is brought in. This device 1 is oriented on the film 50, so that the sections 10, 12 are generally

  perpendicular to the longitudinal edges 52, 54 of the film 50.

  This device 1 can be one of the three devices 1 shown in FIG. 1 or one of those presented below or even any

  which device 1 is suitable for implementing the method according to the invention.

  Preferably, the device 1 has a length approximately equal to half the dimension of the film 50, taken perpendicular to its direction of movement D. The device 1 can be placed near one of the longitudinal free edges 52, 54. Preferably , the device 1 is fixed approximately centered with respect to the two longitudinal free edges 52, 54. A device 1 is guided, pulled or pushed by means on rollers and / or by a reciprocating mechanism to be positioned on the surface of the film 50. The device 1 is disposed on the film 50, so that one of the two strips 2, 4 is laid flat on one face of the film 50, on a portion of the film 50 capable of forming a first bag wall 30. In FIG. 2, it is the strip 2 provided with the veil 6 which rests

on the surface of the film 50.

  The device 1 is advantageously provided prior to its positioning on the film 50, with two welding points 42, 44. Each is located at a longitudinal end 3, 5 of the strips 2, 4 and more precisely at the level of the sections 10, 12 and thus contributes to ensuring the watertightness of the

closing device 1.

  The device 1 is placed on the film 50 under first transverse welding means 110. These first transverse welding means 110 for example, comprise a welding bar 112, transverse and two longitudinal bars 114 relative to the direction of movement D of the film 50. The length of the sealing bar 112 is approximately equal to that of the device 1 to be placed and fixed on the film 50. The two sealing bars 114 are located at the ends of the sealing bar 112, perpendicular to this one, and have a

  length approximately equal to the width of the device 1.

  The sealing bars 112, 114 are then lowered and pressed

  on the edge of the sails 6, 8 together or independently of one another.

  Thus, according to a variant of the method according to the invention, the step of fixing the first web 6 to the film 50 is carried out only by the longitudinal ends 3, 5 of the strips 2, 4, thanks to the longitudinal sealing bars 114. According to another variant of the method according to the invention, the first veil 6 is fixed on the film 50 using the sealing bar 112, only on the edge of the veil 6 intended to be towards the outside of the bag 30 relative to the profiles 10, 12, when this bag 30 is formed. According to yet another variant of the method according to the invention, the fixing of the first web 6, upstream of the chute, is carried out by combining the two preceding variants. Advantageously, for certain closing devices 1, the first veil 6 is fixed at at least two points 47, 49 located on either side of the profile 10 supported by the veil 6, this profile being considered relative to its longitudinal direction . The first web 6 is thus secured to the film 50, at a point situated towards the front and at a point situated towards the rear, relative to the direction of movement D. This makes it possible to prevent the device 1 from turning over during the formation of the sachet on the chute 130 (fig. 2 and fig. 21). A machine according to the present invention can also allow this variant of the

method according to the invention.

  Advantageously also, the fastening of the closure device 1 on the film 50 can be carried out, before formation of the bag 30, simultaneously with the production of the welding spots 42, 44. In this case, the device 1 is routed on the film 50 without that the weld points 42, 44 have not been made. Then, once the device is in place, appropriate sealing bars 114 weld the longitudinal ends 3, 5 of the strips 2, 4

  by the same operation as that which performs the welding points 42, 44.

  In FIG. 3, the formation of a bag 30 is shown from the film 50, around the chute 130. The film 50 provided with the device 1 is conveyed to the chute 130. It is then wrapped around this chute 130. The longitudinal free edges 52, 54 are brought back one on the other, parallel to the axis of the trough 130, to be welded one on the other thanks to longitudinal welding means 120 able to form a weld longitudinal 40. By thus folding the film 50, longitudinally with respect to its direction of movement, a second wall 34 is formed

bag 30.

  A bag 30 has two longitudinal folds 31, 33, an opening closed by the device 1, and is hermetically closed by the longitudinal weld 40 and a transverse weld 46. The transverse weld 46 extends between the longitudinal folds 31, 33 and is located on the edge of the walls 32, 34

  longitudinally opposite the device 1.

  In FIG. 4 are shown second transverse welding means 116. These second transverse welding means 116 are adapted to fix the second web 6 of the device 1 to the second wall 34 of

  bags 30 downstream of the chute 130.

  As shown in FIG. 5, the second transverse welding means 116 make it possible both to weld the device 1 to the walls 32, 34 and to form the transverse weld 46. Preferably, cutting means 140 are mounted integrally with second means of transverse welding 116, in order to proceed to the cutting of the successive sachets. These cutting means 140 are capable of forming a

  transverse cutting relative to the displacement of the film 50.

  Also preferably, the second transverse welding means 116 are each provided with a groove 117. This groove 117 extends over the entire length of the second transverse welding means 116. The grooves 117 of each second welding means 116 are in screw screw and are turned towards each other to form a cavity. These grooves 117 make it possible not to weld the walls 32, 34 to each other over a small transverse area, downstream of the closure device. This transverse zone makes it possible to form tongues 36, 38 allowing the gripping of the walls 32, 34 in order to separate them and open the

bag 30.

  Several variants of the device will be described below.

  1 for the implementation of the method according to the invention.

  FIG. 6 shows a closure device 1 provided, in addition to its webs 6, 8 and its profiles 10, 12, with two strips 18, 20 capable of forming a peelable weld. These peelable weld strips 18, 20 extend over the entire length of the device 1, at the edges of the free ends of the sails 6, 8. This peelable weld 18, 20 therefore joins the sails 6, 8, or parts of sails, of the side which will be located towards the outside of the bag 30 relative to the

  profiles 10, 12, after complete formation of this sachet.

  Figure 7a illustrates, at the second transverse welding means 116, the positioning and welding of the device 1 on the walls 32, 34. The device of Figure 6 is shown in the closed configuration. The peelable weld strips 18, 20 are pre-welded to each other. The free edge of one 6 of the webs 6, 8 of the device 1 is fixed to the wall 34 by means of the first welding means 110. Optionally, according to a variant of the method according to the invention, the peelable weld strips 18, 20 are not pre-welded and are then welded together and to the wall 34 during the operation of fixing the web 6 to this wall 34 by the first welding means 110. According to yet another variant of the method according to the invention, All the walls 32, 34, the webs 6, 8 and the peelable weld strips 18, 20 are welded by the second transverse welding means 116. After the wall 32 has been brought closer to the free edge of the other 8 sails 6, 8, the device 1 is fixed to the walls 32, 34, simultaneously with the formation of the weld 46 and the cutting of the walls 32, 34, between the weld 46 of a bag and the closing device 1 of the next bag (fig. 7b). As described above, the groove 117 of the second transverse welding means 116 makes it possible to keep two zones of the walls 32, 34 which are not welded, in order to constitute tongues 36,

  38 on the side of the sections 10, 12 located towards the outside of the bag 30.

  FIG. 8 shows a closure device provided with two protective strips 14, 16. These protective strips 14, 16 extend over the entire length of the free longitudinal edges of the sails 6, 8. These protective strips are provided a barrier layer on their faces caused to be opposite, which allows the protective strips not to weld together. As shown diagrammatically in FIG. 9, the device 1 is welded to the walls 32, 34 with second transverse welding means 116, not provided with grooves 117. In FIG. 9b, it is noted that the walls 32, 34 are welded to the device 1 both at the level of the peelable welding strips 18, 20 and at the level of the protective strips 14, 16. But the protective strips 14, 16 are not welded together. There are thus tabs 36, 38 capable of gripping the

  walls 32, 34 of the bag 30 in order to open the latter.

  FIG. 10 schematically represents a closure device 1, provided with a line of perforations 22. This line of perforations 22 is, when the device 1 is in the open position between the sections 10 and 12, at approximately equal distance from each. This line of perforations 22 extends over the entire length of the device 1 at the bottom of the

  U-shaped groove formed by the latter, when it is in the closed configuration.

  After opening the bag 30, by separating the peelable weld strips 18, 20 and the complementary sections 10, 12, the device 1 is torn apart.

  level of the perforation line 22.

  FIG. 11 represents a variant of the device 1 presented in FIG. 10. According to this variant, a thin veil 7 forms the groove of the U between the sections 10, 12. This thin veil 7 can easily be torn to open the bag 30 but it provides, as long as it is intact, a means for providing additional sealing to the closure device 1. If this veil 7 extends sufficiently, it can turn towards and between the veils 6, 8 when the contents of the bag 30 are poured, to protect the sections 10, 12 from the contents of the bag 30. The sections 10, 12 thus protected remain clean and able to cooperate effectively with each other when desired

close the bag 30.

  This veil 7 can also form a funnel or a pouring spout, when

  is pulled out of the bag 30 (fig. 12).

  To form a pouring spout, for example, the veil 7 is made up of two roughly trapezoidal elements arranged one on the other and linked together on the two non-parallel edges of the trapezoids and on the shorter edge of the two parallel edges. The length of the longer side of the two parallel edges of the trapezoid is equal to the size of the bag

  transversely to the direction of movement D of the film 50.

  These two non-parallel edges are welded between and with the ends

  longitudinal 3, 5 opposite bands 2, 4.

  In FIG. 13 is shown a closure device 1 comprising, in addition to the peelable weld strips 18, 20, the profiles

  complementary 10, 12 and the sails 6, 8, a sealing membrane 26.

  This membrane 26 is welded over the entire length of the device 1, for example near the peelable weld 18, between this peelable weld strip 18 and the profile 10. This sealing membrane 26 extends laterally in the direction of the another profile 12 coming to cover the profile 10. Figure 14 shows the device 1 shown in Figure 13 in the closed position. We can see that the waterproofing membrane 26 is taken

between profiles 10 and 12.

  FIG. 15 represents a device similar to that of FIGS. 13 and 14, with the difference that it comprises two sealing membranes 26

  each welded to one of the sails 6, 8.

  Figures 16 to 20 show variants of a closure device 1 comprising at least one peelable weld strip 18, 20, 21

and a line of perforations 19.

  FIG. 16 shows a device 1 which has a single peelable weld strip 21 fixed between the webs 6 and 8. the line of perforations 19 is located on the edge of the peelable weld strip 21 situated towards the outside of the bag 30 and between the webs 6 and 8. This line of perforations extends over the entire length of the device 1. It makes it possible to tear off the peelable weld more easily when the walls 32 are moved apart

and 34 to open the bag 30.

  Figure 17 shows a device 1 in the open configuration. The line of perforations 19 is located between the sections 10 and 12, at approximately equal distance from each of them, at the junction of the webs 6 and 8. Strips of peelable weld 18, 20 run along this line of

  perforations 19 over the entire length of the closure device 1.

  FIG. 18 represents, in the closed position, the device 1 of FIG. 17 fixed on a bag 30. To open the bag 30, its walls 32, 34 are moved apart, which induces a stress between the webs 6 and 8 and causes the tearing of the line of perforations 19. This bag 30 could possibly be closed by pressing one on the other the strips of

  peelable solder 18 and 20, if they are for example adhesive tapes.

  This then ensures a greater seal than with cooperation alone

  profiles 10, 12 one with the other.

  Figures 19 and 20 show a closure device such as that shown in Figures 17 and 18, further comprising a sealing membrane 26. This sealing membrane 26 is welded to the web 8, near the weld strip peelable 20 and extends laterally at

above profile 12.

  FIG. 21 shows a closing device fixed on a film 50 (for example before passing over the filling chute 130 of an FFS machine). This device 1 consists of two webs 6, 8 joined together to form a U. The web 6 is fixed to the film 50 by two welding points 47, 49, located on either side of the position of the profile 10 on the web 6. These welding points 47, 49 can be produced before the device 1 is folded back on itself in order to make the sections 10, 12 cooperate with each other. The welding points 47, 49 can be more or less extended in the longitudinal direction of the strips 2, 4. They can optionally also extend over the entire length of the device 1. According to another variant, the device 1 cannot be retained to the film 50 only by a single 47 of these welding points 47, 49. Preferably, in this case the point 47 is that located downstream relative to the displacement D of the film 50, so as to avoid the device 1 overturning in passing on the chute

filling 130.

  Advantageously, one of these welding points 47, 49 is located on the side of the sections 10, 12 which will be inside the bag 30 once it has been formed. In this case, no equivalent welding point will be made opposite, on the second web 8. In this way, a hinge configuration is formed which offers better resistance to

  internal pressure in the bag 30 (Figure 22).

  It will be understood that the invention also extends to a machine for manufacturing a film 50 intended to form sachets 30, comprising first welding means 110 transverse to the direction of movement of the film 50, capable of fixing a closing device 1 provided

sails 6, 8 on the film 50.

  The invention also extends to a machine for forming, filling and automatic closings, which comprises first transverse welding means, upstream of a chute 130 for filling and

  second transverse welding means 116 downstream of the chute 130.

  The concept of transversality being understood here with reference to the direction of movement of the film 50. It will also be understood that the invention relates to a film 50 for the formation of sachets 30, provided with closing devices 1 such as those described above with only the first veil 6 attached to the

film 50.

Claims (34)

  1. A method of manufacturing a film (50) intended to form sachets (30), comprising the steps of moving the film (50) and sequentially fixing it on the film (50) and transversely with reference to the direction of displacement (D) thereof, a closure device (1) comprising a first strip (2) supporting at least one closure profile (10), in engagement with another closure profile (12) which is complementary thereto and supported by a second strip (4), or a part of the first strip (2), which will be fixed to the film (50) later, characterized in that each strip (2, 4) comprises at least one veil (6, 8 ) extending widely laterally on one side of the section or sections (10, 12) supported by each strip.   2. Method according to claim 1, characterized in that the fixing step is carried out by welding the film (50) with at least one area of the   sails (6, 8) different from that located under the profiles (10,12).   3. Method according to one of claims 1 and 2, characterized in that   at least one veil (6, 8) extends laterally over an area at least   equal in surface to that located under the profiles (10,12).   4. Method according to one of the preceding claims, characterized   in that it is used to form sachets (30) on a   automatic formation, filling and closing.   5. Method according to one of the preceding claims, characterized   in that it is used to fix, on the film (50), a closure device (1) comprising two complementary profiles (10, 12), each supported by one of the two parts (6, 8) facing each other a single U-shaped veil, in cross section with respect to the longitudinal direction of the profiles (10, 12).   6. Method according to one of claims 4 and 5, characterized in that   that a step of fixing a first web (6) on the film (50) is carried out upstream of a filling chute (130) of the forming machine,   automatic filling and closing.   7. Method according to one of claims 4 to 6, characterized in that   that a step of fixing a second web (8) on a second wall (34) of   bag (30) is made downstream of the chute (130).   8. Method according to one of the preceding claims, characterized   in that it is used to fix the closure device (1) so that the profiles (10, 12) are generally perpendicular to the   longitudinal edges (52, 54) of the film (50).   9. Method according to claim 8, characterized in that it is used to fix the closure device (1) approximately   centered with respect to the longitudinal edges (52, 54) of the film (50).   10. Method according to one of the preceding claims, characterized   in that the fixing of a first veil (6) on the film (50) is carried out by   the longitudinal ends (3, 5) of the strips (2, 4).   1l. Method according to one of Claims 1 to 9, characterized in that   that the fixing of a first veil (6) on the film is carried out on the edge of the veil (6) intended to be towards the outside of the bag (30) relative to the profiles (10, 12)   12. A method characterized in that it conforms to the claims and 11 taken in combination.   13. Method according to one of the preceding claims, characterized   in that the step of fixing the first web (6) to the film (50) is carried out at a single point (47, 49) located downstream from the displacement (D) of the film (50).   14. Method according to one of the preceding claims, characterized   in that the step of fixing a first web (6) to the film (50) is carried out with at least two points (47, 49) located on either side of the profile (10) supported by this web (6), this profile (10) being considered   relative to its longitudinal direction.   15. Method according to one of the preceding claims, characterized   in that the step of fixing the first veil (6) to the film (50) is carried out with a welding point located on the side of the profiles (10, 12) which will be inside the bag (30), once it has formed and in that there is no equivalent welding point located opposite, on the second web (8), this configuration in particular making it possible to constitute a hinge opposing better resistance to a internal pressure at bag (30).   16. Method according to one of the preceding claims, characterized   in that it is used to fix on the film (50), a closure device (1) comprising a peelable weld (18, 20, 21) joining the sails or parts of sails (6, 8), on the side which will be located towards the outside of the bag (30) by   relative to the profiles (10, 12), after complete formation of this bag (30).   17. Method according to one of the preceding claims, characterized   in that it is used to fix on the film (50), a device (1) for closing while preserving an area of the walls (32, 34) of the bag (30), not welded, of the   side of the profiles (10, 12) located towards the outside of the bag (30).   18. Method according to one of the preceding claims, characterized   in that it is used to fix on the film (50), a closure device (1) comprising two protective strips (14, 16), which do not weld together, to form tabs (36, 38 ) suitable for gripping walls (32, 34).   19. Method according to one of the preceding claims, characterized   in that it is used to fix on the film (50), a closure device (1) which comprises a sealing membrane (26) caught between the profiles (10, 12).   20. Method according to one of the preceding claims, characterized   in that it is used to fix on the film (50), a device (1) which comprises   a membrane (7) capable of forming a pouring spout or a funnel.   21. Method according to one of claims 5 to 17, characterized in that   that it is used to fix on the film (50) a closing device (1) provided with a line of perforations (19, 22) between the profiles (10, 12) and at   approximately equal distance from each of them.   22. Machine for manufacturing a film (50) intended to form   sachets (30), by the method according to one of the preceding claims,   characterized in that it comprises first transverse welding means (110), relative to the direction of movement of the film (50), capable of fixing a closure device (1) provided with webs (6, 8), on the film (50).   23. machine for manufacturing a film (50) according to claim 22, characterized in that the first welding means (110) are able to weld only one zone of the webs (6, 8) different from that located under the profiles (10, 12).   24. Automatic forming, filling and closing machine   for implementing the method according to one of claims 4 to 21,   characterized in that it comprises first welding means (110), upstream of a filling chute (130) and second welding means (116) downstream of the chute (130), these first and second means welding (110, 116) being transverse with reference to   the direction of movement of the film (50).   25. Machine according to any one of claims 22 to 24,   characterized in that the first (110) and second (116) welding means are able to weld only one zone of the webs (6, 8) different from   the one located under the profiles (10, 12).   26. Machine according to any one of claims 22 to 25,   characterized in that it allows the first veil (6) to be fixed, at at least two points (47, 49) located on either side of the profile (10) supported by this veil (6), this profile (10) being considered in relation to its longitudinal direction.   27. Machine according to one of claims 22 to 26, characterized in   that the first welding means (110) comprise two longitudinal bars (114), relative to the direction of movement (D) of the film (50), capable of carrying out the fixing of a first web (6) on the film (50), by the longitudinal ends (3, 5) of the strips (2, 4).   28. Machine according to one of claims 22 to 27, characterized in   that the first welding means (110) comprise a welding bar (112) capable of fixing a first web (6), on the film (50), only on the edge of this web (6) intended to be towards the outside of the bag (30) relative to the profiles (10, 12), when this bag (30) is formed. 29. Device (1) for closing bags (30) for implementation   of the method according to claims 1 to 21 characterized in that it comprises   two sails (6, 8) extending widely laterally on at least one side   of a set of one or more profiles (10, 12).   30. Device according to claim 29, characterized in that it comprises a peelable weld (18, 20, 21) joining the sails (6, 8) or parts of sails, on the side which will be located towards the outside of the bag ( 30) by   relative to the profiles (10, 12), after complete formation of this bag (30).   31. Device according to one of claims 29 and 30, characterized in   what it can be fixed on walls (32, 34) while retaining a zone of the walls (32, 34) of bag (30), not welded, on the side of the profiles (10,   12), located towards the outside of the bag (30).   32. Device according to any one of claims 29 to 31,   characterized in that it comprises two protective strips (14, 16), which do not weld together, to form tongues (36, 38) suitable for gripping the walls (32, 34).   33. Device according to any one of claims 29 to 32,   characterized in that it comprises a sealing membrane (26) intended   to be taken between the profiles (10, 12).   34. Device according to any one of claims 29 to 33,   characterized in that it comprises a membrane (7) capable of forming a spout pourer or funnel.   35. Device according to any one of claims 29 to 34,   characterized in that it is provided with a line of perforations (19, 22), between   the profiles (10, 12) and at approximately equal distance from each of them.   36. Film for the formation of sachets (30) provided with device (1) for   closure according to any one of claims 29 to 35, with   only a first veil (6) fixed to the film (50).