WO2002047982A1

WO2002047982A1 - Installation for packaging liquid doses in sealed bags and use thereof

Info

Publication number: WO2002047982A1
Application number: PCT/IB2001/002296
Authority: WO
Inventors: Etienne Susini
Original assignee: Walk Pak Holding Nv
Priority date: 2000-12-12
Filing date: 2001-12-04
Publication date: 2002-06-20
Also published as: US20030208993A1; EP1215121A1; AU2002218435A1; EP1361981A1

Abstract

The invention concerns an installation for packaging liquid doses in sealed bags produced from a longitudinally open blown tubing (G), comprising a vertical frame (B), means (50, 51, 74-77) for moving along said blown tubing (G), a pipe (41) supplying said liquid, means for welding (38, 39) said opening, means for welding (68) the opposite edges of said tubing (G) beneath the end of said pipe (41) and cutting means (42, 43, 72, 73). A first welding and cutting station (3) is arranged on either side of said pipe (41), to provide first weld seams and cuts, a second welding and cutting station (4) is arranged beneath the end of said pipe (41) to produce transverse weld seams to link the two adjacent ends of the first weld seams located on either side of said feeding pipe of two adjacent pairs of said first weld seams and to form cut-outs.

Description

INSTALLATION FOR PACKAGING LIQUID DOSES IN WATERPROOF BAGS AND ITS USE.

The present invention relates to an installation for conditioning doses of liquid in sealed bags made from a sheath of a flexible heat-sealable material, open longitudinally, comprising a vertical frame comprising means for making the sheath pass from above below, a supply rod for said liquid entering said sheath through said longitudinal opening, means for welding said longitudinal opening below the passage of said filling rod through said longitudinal opening, transverse welding means for connecting the opposite longitudinal edges of said jacket below the end of distri bution ^¬ of said rod feeding and cutting means for separating the pouches containing said doses, and the use of this facility.

A sachet of this type, further comprising a valve adjacent to a pocket containing a straw, one end of which is engaged in the inlet of the valve, its manufacturing and packaging process are described in EP-0 948 446. In this Regarding the actual packaging, this document however gives relatively few details and does not disclose the means used for this purpose. It does not disclose a solution allowing continuous packaging. As described, the shape of the sachets is given by the edges of the strip material and by transverse welds, connecting the two longitudinal edges of the strip material, giving a quadrilateral profile to the sachet.

The process of continuous vertical packaging of bags of cartons or parallelepiped bricks from a continuous tubular material is well known. However, the vertical packaging installations used for this purpose only make it possible to produce volumes with a quadrangular profile or volumes with regulated surfaces, dictated by the tubular shape of the sheath from which they originate, leaving little or no room for fantasy and not allowing to give an original character, even playful to the sachets thus produced. In addition, a given installation can only produce sachets of identical shape and size. Only the decoration and / or the inscriptions carried on the external surface of the sachet make it possible to personalize the sachet according to the product which it contains and / or the brand of the manufacturer of the product packaged in this sachet.

The main object of the present invention is to allow the liquid to be conditioned continuously, advantageously, but not exclusively, in the blanks of sachets as described in the above-mentioned document and to form sachets capable of having various shapes and easily modifiable as desired. the needs or the shape that you want to give to the sachet with a minimum of work.

To this end, the present invention firstly relates to an installation for conditioning doses of liquid in sealed bags made from a sheath of a flexible heat-sealable material, according to claim 1. It then relates to a use of this installation according to claim 10.

One of the advantages of this installation is to give the sachet most of the shape of its periphery before filling, leaving between the two welded parts on either side of the filling cane only a passage for this cane. , so that the liquid is practically already confined to the periphery of the sachet. This welding, giving the essentials of the shape of the bag, is accompanied by cutting. to separate the welded portions of the sheath in which the bag is formed. Thanks to this design, it becomes possible to vary the shape of the periphery given to the bag, since it is no longer dictated by the straight edges of the tubular sheath.

Therefore, simply change the welding and cutting tools to change the profile given to the bag. The association of a given profile with an impression appropriate to the profile makes it possible to give particular aspects to the bag. Thus, for example, the profile can recall that of a fruit, the impression of the sachet then reproducing that of the skin of the fruit. Such a sachet can then be used to condition the juice of the fruit, the sachet of which reproduces the appearance. This aspect is obviously not limited to the above example; it can take that of imaginary or real characters, caricatures, objects reminiscent of sporting events, animals etc. The profile given to the bag can also be chosen to evoke a theme used in the context of an advertising campaign. Advantageously, in the case where the packaging installation is used for filling sachets whose blanks are produced according to the abovementioned EP-0 948 446, the work stations of the installation relating to the packaging of the liquid itself are preceded by a station intended to open the bottom of a pocket adjacent to the valve channel and to place a straw in this channel and in the adjacent pocket.

Other features and advantages of the present invention will become apparent on reading the description which follows made in connection with the appended drawings representing, schematically and by way of example, a particular embodiment of the installation which is the subject of this invention and its use. Figure 1 is an elevational view of this embodiment; Figure 2 is an enlarged partial view of Figure 1, illustrating the first welding and cutting station; Figure 3 is a view along III-III of Figure 2, welding and cutting tool removed; Figure 4 is a partial view of the welding and cutting tool alone seen along IV-IV of Figure 2; Figure 5 is a view along VV of Figure 1 showing the second welding and cutting station; FIG. 6 is a perspective view of the welding and cutting tools alone intended to be associated with the second welding and cutting station of FIG. 5; Figure 7 is an enlarged partial view of Figure 1; Figure 8 is a sectional view along VIII-VIII of Figure 7; Figure 9 is an enlarged partial view of a detail of Figure 8; Figure 10 is a diagram of the following operations of the second welding and cutting station.

The installation illustrated in FIG. 1 comprises a frame B comprising two parts side by side Bl and B2. The part Bl is intended for the formation of straws P and for feeding them in sachets of which blanks, in this example, are previously formed in a strip material in the form of a flattened sheath G. This sheath G is stored under the form of a coil (not shown) and is brought to the part B2 of the frame B by a roller 1, arranged at the top of this part B2 which is more specifically the object of the present invention.

This sheath G is open longitudinally along its left edge with reference to FIG. 1. In this example pie, going down, this sheath G passes through a straw loading station 2. This is obviously only necessary if straws P must be loaded into the bags formed in the sheath G and more particularly when these bags are provided valves. The sheath G then passes through a first welding and cutting station 3 and through a second welding and cutting station 4.

The first welding and cutting station 3 is shown in more detail in FIGS. 2 to 4 and includes a support frame 5 connected to the frame B2 by two slides 6 mounted on two vertical slides 7 secured to each of their ends by two plates fixing 8 parallel, fixed to the frame B2 by bolts 9. Clamping nuts with fins 10 are used to fix the slides 6 on the vertical slides 7. An adjustment wheel VR is integral with a shaft 70 whose end is in engagement with a screw jack 71 intended to vertically move the support frame 5 on the vertical slides 7. This adjustment is intended to adapt the position of the welding and cutting station as a function of the size of the sachets in which the liquid is conditioning.

Two tool supports 11 and 12 are slidably mounted each on two slides 13, respectively 14 fixed to two parallel sides of the support frame 5. Each of these supports 11, 12 is connected to a jack 15, respectively 16, for sliding these supports on the slides 13, 14. Each tool support 11, 12 comprises two tool holders 17, 18, respectively 19, 20. Each tool holder 17-20 has a fixing pin 21, 22, 23, respectively 24, each of which passes through supports 25, 26, 27, respectively 28, having the form of pairs of parallel plates, pierced with coaxial openings. At one of their ends, the fixing pins 21-24 end with heads 21a, 22a, 23a, respectively 24a, while keys 21b, 22b, 23b, respectively 24b hold them at their other ends.

The two tool holders 17, 18, respectively 19, 20 of the tool supports 11, 12 are slidably mounted each on two slides 29a, 29b respectively 30a, 30b. Wing nuts 17a, 18a, 17b, 18b, 19a, respectively 20a, two other nuts, symmetrical to the last two 19a, 20a not being visible, serve to tighten the tool holders 17-20 on the slides 29a, 29b , 30a, 30b. Two adjustment levers 31, 32 (FIG. 2) are integral with pins of which a threaded part is engaged with a nut (not shown), integral with each of the supports 17, respectively 18. These adjustment levers 31, 32 serve to move the supports relative to the slides 29a, 29b.

Figures 2 and 4 show in more detail three of the four tools, the fourth not being visible, 33, 34 and 35 mounted on the four tool holders 17-20. Each tool 33-35 has on its rear face a fixing block, of which only two 36, 37 are visible in FIG. 4. Each block is traversed by a bore 36a, 37a, intended for the passage of a fixing dowel 21, 23 respectively, the other two bores not being visible.

Each tool 33, 34 has, in its upper part, a welding electrode 38, 39 which can be seen in broken lines in FIG. 2. The flat surfaces of the tool 35 and of the non-visible tool making opposite the tool 34, are located opposite the electrodes 38, respectively 39 and constitute counter-electrodes. The welds formed by the two electrodes 38, 39 define the entire periphery of the bag with the exception of a vertical passage 40 (Figure 2) formed between the tools 33, 34 on the one hand and between the tool 35 and the tool not visible located in front of tool 34 (figure 2). The vertical passage 40 is intended to allow a liquid supply rod 41 to pass (FIG. 1).

The lower parts of the two tools 33, 34 (FIGS. 2 and 4) each comprise a mobile knife 42, 43 actuated by a jack 44, 45. These mobile knives 42, 43 have a shape corresponding to the outer edge of the welding electrodes 38, 39. The two tools, of which only the tool 35 is visible, have, opposite each movable knife 42, 43 a receiving groove, of which only the groove 46 is visible in FIG. 4, of shape corresponding to that of the movable knife 42.

The actuation mechanism of the second welding and cutting station 4 is illustrated in more detail in FIG. 5, while the tools intended to be associated with this actuation mechanism are illustrated in FIG. 6. The assembly of this actuation mechanism is carried by a • horizontal rectangular chassis 47, integral with two vertical slides 48, 49, each engaged with a linear motor 50, 51, each of which is fixed to the frame B2 (FIG. 1) by angles mounting 52.

The two short sides of the rectangular chassis 47 each carry a jack 53, 54, each of them being engaged with a slide 55, respectively 56, mounted on the chassis by means of guide rails (not shown) running along the two sides 47a, 47b of the chassis 47. The slide 55 carries a slide 57 movable perpendicular to the slide 55 by drive motors Ml, M2, that is to say transversely to the chassis 47. The slide 56 also carries a slide 58 also movable transversely to the chassis, by drive motors M3, M4.

Each slide 57, 58 carries two tool holders 59, 60, respectively 61, 62, each secured to a jack 63, 64, respectively 65, 66. A free roller 67, arranged transversely to the center of the frame 47 is intended to receive the bottom of the sheath G.

The tools intended to be mounted on the second welding and cutting station 4 are illustrated in perspective by FIG. 6. These tools include a welding electrode 68 located opposite a counter electrode 69, these two members 68, 69 being fixed to the supports 60, 62 by fixing pieces 100. Advantageously, the counter-electrode 69 is associated with cooling means. The other two supports 59, 61 carry the cutting members 72, 73. While the member 73 is a fixed counter-cutting member connected to the support 59 by fixing parts 100, the cutting member 72 is formed by a block mounted sliding on fixing rods 101 and pressed in the direction of the counter-cutting member 73 by return springs 102. This mounting allows the block to move back when it meets the counter-cutting member 73 and then let out the knives (not visible). The welding members 68, 69 and cutting 72, 73 are shaped to simultaneously close and then cut, the lower and upper parts of two adjacent sachets, to connect to each other, through the space 40 left free, the welds made in the first welding and cutting station 3 by the electrodes 38 and 39, thus forming a continuous weld delimiting a packaging volume for the liquid.

Two pairs of pinch lips 74, 75; 76, 77, are arranged respectively above and below these welding tools 68, 69 and cutting 72, 73 and are intended to be fixed to the slides 55, respectively 56. The lips 74 and 76 advantageously have an attached tongue 74a, 76a made of an elastically compressible material, such as an elastomeric material used to make the seals. These lips are used to pinch the sheath G during the welding and cutting operations. Since, as will be explained in the description relating to operation, the work station is moved up and down by the linear motors 50, 51 during the welding and cutting operations, the nipping lips 74-77 are also used to pull the sheath G without slipping during these welding and cutting operations. According to a preferred form of the present invention, the sachets formed by the welding and cutting units 3, 4 include a valve, for example, like the sachet described in EP-0 948 446.

The packaging installation according to the present invention comprises, upstream of the welding and cutting stations 3, 4, a station 2 for loading the straws P into the channels formed by the valves formed in the sheath G. This station will now be described with particular reference to Figures 7 and 8. A transfer disc 78 is pivotally mounted about a horizontal axis perpendicular to the plane of the sheath G. For this purpose, the center 78a of the disc 78 is fixed and the disc 78 is fixed to a drive hub 78b pivotally mounted by means of ball bearings 79. A pinion 78c secured to the hub 78b is connected to a pinion 80a of a drive motor 80 by a toothed belt 81. The surface of the disc carries twelve radial slides 82, slidably mounted in supports 82a. Each radial slide 82 is pushed towards the center of the transfer disc 78 by return springs 83 and each of them carries a pusher 84. Radial housings 82b are mounted in the radial slides 82 to receive the straws P. A radial slide 82 on two carries a straw P folded in the insertion position. Advantageously, these straws are previously shaped as described in WO 99/3791. The pushers 84 of the other radial slides 82 located between those which carry the straws P are shaped as perforation members. In fact, the valves V described in EP 0 948 446 mentioned above occupy the right part of the sheath G (FIG. 7) and their inlet is closed by a cover which the pushers 84 shaped as perforation members are intended to perforate to give access to the valve channel V.

FIG. 9 shows the device for guiding and clamping the different layers of films forming the sheath in which the valves V are formed. In fact there are two guiding and clamping devices 85, 86, one located above and the other below the axis of perforation and insertion of straws P, constituted by a horizontal line passing through the center of the transfer disc 78.

Each guide and clamping device 85, 86 co - carries two fixed support surfaces 87, 88 arranged in a V shape between which pass the edge of the transfer disc 78, as well as the ends of the slides 82, 82a. These support surfaces 87, 88 are fixed to a part of the frame B2. Clamping surfaces 89, 90, 91 are integral, one 89, with a cylinder 92, the other 90, 91 with a cylinder 93. Two other cylinders, associated with homologous clamping surfaces, and of which only the cylinder 93a is visible in FIG. 7 operate in an identical manner and serve the same purpose as the cylinders 92, 93. They are arranged symmetrically above the valve V and thus make it possible to tighten the layers of film of the sheath G above this valve V. A film intended to form the outside wall of the sachets as well as a film intended to form the seal of closing of a pocket to contain the curved part of the straw P are disposed between the support surface 87 and the clamping surface 89. The film forming the other wall of the bag and a first film forming the valve V are tightened between the two clamping surfaces 90, 91, while the second film of the valve is clamped between the clamping surface 91 and the bearing surface 88. Ball and spring spacers 94, 95 are intended to separate the two clamping surfaces 90, 91 in the open position of the jack 93.

The fixed center 78a of the transfer disc 78 carries a jack 96 aligned with the horizontal axis of perforation and insertion of straws P passing through the center of this transfer disc 78 and through the valve channel V aligned with the diameter of this transfer disc 78.

A feeding station 97 for the transfer disc 78 in straws P is diametrically opposite to the loading station 2 for straws P in the channels of the valves V. This station includes fiber optic positioning means 98, to ensure precise angular alignment transfer disc 78. A pusher 99 is slidably mounted along an axis passing through the center of the transfer disc 78. The front part of this pusher 99 has a smaller diameter than the rear part, in order to be able to penetrate into the duct of the straw P to keep it aligned by pushing it into a housing 82b secured to the transfer disc 78.

The operation of the packaging installation will now be explained with reference to FIGS. 10 and 11 which give the chronology of the operations relating to the first and second welding and cutting stations 4. Since the operations relating to the processing station loading of straws 2 takes place on the sheath G at standstill, like those of the first welding and cutting station, while the second welding and cutting station 4 also serves to advance the sheath step by step and therefore performs an alternating vertical movement simultaneously with the welding and cutting operations, the operations of the straw loading station 2 and the first welding station and cutting 3, are carried out between the operations of the second welding and cutting station 4.

First of all, it should be noted that the liquid supply rod 41 descends to a level arriving at mid-height of the cutting tools 42, 43 (FIGS. 1, 2 and 4), that is to say at a level located substantially below the first welding station, thus making it possible to supply the liquid with a continuous and constant flow rate without the liquid overflowing. During the stopping of the sheath G, the straw loading station 2 first of all performs the drilling operation of the film closing the inlet of the valve V. For this purpose, the jacks 92, 93 tighten the surfaces d pressing and clamping 87-91 against each other, immobilizing the sheath G. The jack 96 placed in the center of the transfer disc 78 is actuated and pushes the slide 82 secured to a drill 84 in the direction of the sheath G for creating an opening through the latter allowing access to the channel of the valve V. The jack 96 goes back and the slide 82 is brought back by the return springs 83.

Then, the motor 80 rotates the transfer disc 78 by 30 °, corresponding to an angular pitch separating two adjacent slides 82, to place a slide 82 in which a straw P has been loaded. The jack 96 is then actuated again to engage the front end of the straw P in the channel of the valve V. The depth of engagement of the straw P in the valve V is chosen so that the valve remains closed. The cylinder 96 returns in its initial position and the springs 83 bring the slide 82 back, while the straw P remains engaged in the channel of the valve V.

The drilling and loading operations for the straw P which have just been described are carried out simultaneously with the welding and cutting operations of the first welding and cutting station 3. The chronology of these is illustrated in FIG. 10 The cylinders 15 and 16 press the tools 33, 34 and the tools which face them and of which only the tool 35 is visible in FIGS. 2 and 4, one against the other. The welding electrodes 38, 39 are then supplied with current pulses to weld the sheath G. Then, the actuator 44 is actuated to cause the knives 42, 43 to penetrate into the receiving grooves which face them and of which only the groove 46 is visible in FIG. 4, thus cutting the sheath G outside the welds formed by the electrodes 38, 39 and thus separating them from the rest of the sheath G.

As can be seen in FIG. 1, the welding electrodes 38, 39 and the knives 42, 43 are at two different levels, so that the welding and cutting operations carried out almost simultaneously by the welding station and cutting, are carried out on two different sachets succeeding each other along the sheath G. Thus, a sachet is welded while that which is just below it is filled with liquid and simultaneously cut. During the following operating cycle, the sachet which has been welded is lowered by one step and is therefore opposite the knives 42, 43. The chronology of the welding and cutting operations of the second welding station and of section 4 is illustrated by FIG. 11 with more specific reference to FIGS. 5 and 6. Firstly, which is located at the end of the operations. tions of the first welding and cutting station 3, the jacks 53, 54 push the tools 72-77 against each other, so that the sheath G is pinched between the lips 74, 75, on the one hand, and between the lips 76, 77 on the other hand, these two nip lines lying above, respectively below the welding tools 68, 69 and cutting 73, 74. During the operations which will follow, the assembly organs mounted on the chassis 47 will be driven downwards by the linear motors 50, 51. The length of the downstroke will correspond exactly to the length separating two successive sachets or to that separating two successive valves V, which amounts to the same thing. However, while the valves V are formed on the sheath G with regular and precise spacings before the operation of conditioning the liquid in the sachets, the sachets are formed only during the conditioning operation, simultaneously with it, so that it is the valves V which serve as means of reference.

Then, the jacks 64, 66 controlling the welding tools 68, 69 corresponding to the welding electrode and counter-electrode, press these tools against each other. The electrodes are supplied with pulsed current, which makes it possible to limit the welding time, then to cool immediately afterwards in an extremely short time, the counter-electrode 69 being able to serve as a cooling member by being connected to means (not shown) for example a bimetal with Peltier effect, to quickly lower its temperature, while keeping the welded parts tight, which is not possible with resistance heating. Cooling after welding while keeping the parts tight is important in this case. Indeed, at the time of this welding, the bag is filled with liquid and has therefore been deformed, so that the welded surface gondola. By keeping it tight during cooling, the appearance of this welded portion is significantly improved.

Then the jacks 64, 66 are open and it is the slides 57, 58 to be moved by the drive motors Ml, M2, M3, M4 to bring the cutting tools 72, 73 in place of the welding tools , that is to say by moving the sliders 57, 58 to the right with respect to FIG. 5. After this displacement, it is the jacks 59 and 60 which bring the cutting tools 72, 73 together by projecting the knives from the tool 72 for making them penetrate into the grooves of the counter-cutting tool 73 by cutting in passing the sheath portion G corresponding to the previously welded portions. Note in Figure 6 that the welded portions and the cut portions are used to connect to each other the two portions previously welded by the electrodes 38, 39 (Figure 2) and cut by the knives 42, 43, share and other of the space 40 left free to allow the passage of the liquid supply rod 41. However, while the first welding and cutting station 3 performs the welding and cutting operations respectively on two successive sachets, the second welding and cutting station 4 simultaneously performs welding and then cutting of two lower, respectively upper, parts of two successive sachets. At the same time, the lower bag, the upper part of which has been sealed, is separated from the sheath G after the cutting operation.

Once the cutting is complete, the jacks 59, 60 are brought back, then it is the turn of the jacks 53, 54 to be brought back. At the same time, at the end of this welding and cutting operation of the second welding and cutting station 4, the sheath G is lowered by a step corresponding to the height of a sachet, so that the first welding and cutting station 3 can start its operating cycle again.

While the first welding and cutting station 3 is carrying out its operations, the chassis 47 of the second welding and cutting station 4 is brought up one step by the linear motors 50, 51.

It is also during this time interval that the operations of perforation and loading of straw 2 take place that we will describe, since it is also on the stationary sheath that these operations are carried out. After displacement of the sheath G by the second welding and cutting station 4, a valve V is aligned in the extension of the diameter of the transfer disc 78. A slide 82 carrying a piercing 84 is positioned on the diameter of the disc transfer 78 aligned with the valve conduit V. The four cylinders 92, 93, 93a (the cylinder 92a not being visible) push the bearing surfaces 89, 90 against each other as well as against the support surfaces fixed 87, 88, on either side of the valve V. The intermediate support surface 91 is clamped between the support surfaces 90 and support 88. The different layers of film forming the sheath G are thus firmly held on either side of valve V.

The jack 96 pushes the radial slide 82 in the direction of the valve V, so that the piercer 84 perforates the film which closed the inlet of the channel of the valve V. It will be recalled that in this example, it is assumed that the sheath G and the valve V are shaped as described in EP-0 948 446 to which one can refer. However, the invention can obviously also be applied to other types of sachets provided with valves. When the jack 96 moves back, the return springs 83 bring the slide 82 back with the piercer 84. The motor 80 then drives the transfer disc one step, in this example, this step corresponding to 30 °, thus placing a next slide 82 carrying a straw P on the line connecting the center of the transfer disc 78 to the channel of valve V. The jack 96 is again actuated to push the slide 82 and engage the straw P in the channel of the valve V. Once the engagement of the straw P is completed, the four jacks 92, 93, 93a ( the cylinder 92a not being visible) recoil, loosening the film layers of the sheath G.

Simultaneously with the straw loading operation

P in the valve channel, the pusher 99 diametrically opposite the valve V with respect to the transfer disc, is also actuated to push a straw P in the slide 82 diametrically opposite.

This operation of perforating and loading the straw P being simultaneous with the operation of the first welding and cutting station 3, a new cycle of the second welding and cutting station 4 with drawing of the sheath G can start again.

Claims

1. Installation for conditioning doses of liquid in sealed bags made from a sheath (G) of a flexible heat-sealable material, open longitudinally, comprising a vertical frame (B) comprising means (50, 51, 74-77) to scroll this sheath (G) from top to bottom, a feed rod (41) of said liquid penetrating said sheath (G) through said longitudinal opening, welding means (38, 39 ) from said longitudinal opening below the passage of said feed rod (41) through said longitudinal opening, transverse welding means (68) for connecting the opposite longitudinal edges of said sheath (G) below the distribution end of said feed rod (41) and cutting means (42, 43, 72, 73) for separating the sachets containing said doses from said sheath, characterized in that it comprises a first welding station and cutting (3), arranged by t and other of said feed rod (41), to provide first welds and cuts outside these first welds, a second welding and cutting station (4) below the end of said supply rod (41), to form transverse welds to connect the two adjacent ends of the first welds located on either side of said supply rod of two adjacent pairs of said first welds and to form cutouts to the exterior of said transverse welds.

2. Installation according to claim 1, characterized in that said first and second welding and cutting stations (3, 4) each comprise at least two supports (11, 12; 59-62) arranged on either side of said sheath (G), guide means (13, 14; 47a, 47b) of these supports (11, 12; 59-62) in a direction transverse to the travel of said sheath (G), actuation means (15, 16; 53, 54) to move said supports (11, 12; 59-62) along their respective guide means, in opposite directions to each other to bring them closer or away from each other, welding means (38, 39, 68, 69), cutting means (42, 43, 72, 73) and fixing means (21-24, 36, 100, 101) for connecting said welding means (38 , 39, 68, 69) and cutting (42, 43, 72, 73) removably to said respective supports (11, 12; 59-62).

3. Installation according to one of the preceding claims, characterized in that the supports (59, 60) of the cutting and welding means (69, 73) of said second welding and cutting station (4) located on one side of said sheath (G) and the supports (61, 62) of the cutting and welding means (68, 72) of this same welding and cutting station (4) located on the other side of said sheath (G) are each integral with an independent actuating member (63-66) for moving the supports (59, 60) arranged on one side of said sheath (G) and those (61, 62) arranged on the other side of this sheath (G), against each other and to separate them from each other, and in that two sliding devices (57, 58), are displaceable according to two horizontal trajectories and parallel to each other, each of them being kinematically integral with two of said supports (59, 60, 61, 62) located on the same side of said sheath (G), and are taken e with drive means (M1-M4) for sliding them along said paths, alternately in two opposite directions, so as to alternate said welding means, respectively cutting in a working position determined relative to said sheath (G).

4. Installation according to claim 3, characterized in that each of the two sliding devices (57, 58) kinematically integral with said respective supports (59-62) arranged on either side of said sheath (G), are integral with two respective sliding members (55, 56) mounted on guide means (47a, 47b) defining a horizontal trajectory, perpendicular to those of said sliding devices (57, 58), said sliding members each engaging with means drive (53, 54) to bring them closer, alternately away from one another, pinching means (74-77) of said sheath (G) being integral with said sliding members (55, 56) , the guide means (47a, 47b) of these sliding members (55, 56) being integral with a frame (47) engaged with vertical guide and drive means (50, 51) for driving said frame alternately from top to bottom and from bottom to top, the long ur of this race being determined as a function of the vertical dimension of said sealed bags.

5. Installation according to claim 3, characterized in that the vertical position of the welding means (38, 39) and cutting (42, 43) of said first welding and cutting station is fixed during the packaging process, these means welding (38, 39) and cutting (42, 43) being aligned vertically on either side of said sheath (G) with a spacing corresponding to the pitch separating two of said successive sealed bags.

6. Installation according to claim 5, characterized in that said welding means (38, 39) and cutting (42, 43) are integral with a common support (5) connected to said frame (B2) by height adjustment means (7, 70, 71, VR) and locking (10) of these adjustment means.

7. Installation according to one of the preceding claims, characterized in that said welding means (38, 39, 68) are constituted by electric pulse heating means.

8. Installation according to one of the preceding claims, characterized in that said welding means

(68) have a counter support (69) associated with cooling means.

9. Installation for conditioning doses of liquid in sealed bags comprising a valve (V) formed by a channel formed between two thermoplastic films disposed inside said sheath at the location of each of said bags, extending transversely to said sheath and a pocket whose bottom is adjacent to the inlet of said valve channel (V), according to one of the preceding claims, characterized in that it comprises, upstream of said first welding station and cutting (3), a station (2) for introducing one end of a straw (P) into said valve channel (V), this station (2) comprising means (84) for piercing the bottom of said pocket adjacent to the inlet of said valve channel (V) and means (82) for inserting one end of a straw (P) into the inlet of said valve channel (V) and the rest of said straw (P) in said pocket .

10. Installation according to claim 9, characterized in that said station (2) for introducing a straw (P) into said valve channel (V) comprises means (87-93) for flattening and tightening said sheath (G), on either side of said valve channel (V), a transfer disc (78) pivotally mounted and substantially coplanar with said sheath (G) flattened, a plurality of radial housings (82b) for said straws (P), distributed equiangularly on this transfer disc (78), an equivalent series of radial guide means (82) for said means (84) for piercing the bottoms of said pockets, alternating with said housings (82b), means (80, 81) for moving said transfer disc (78) step by step to successively bring a piercing member (84) and one of said radial housings (82b) in alignment with each of said valve channels (V), and means (96) for moving radially and alternately outward from said transfer disc (78) said piercing member (84) and said straw (P) when they are respectively in alignment with said valve channel (V).

11. Use of the installation according to one of the preceding claims for conditioning by continuous rerα- pleating of said sheath (G) by said liquid simultaneously with the steps of welding and cutting of the periphery of said sachets.