EP0893241A1 - Method and apparatus for adhering automatically a heat-shrinkable plastic film on the bottom of an open crate. - Google Patents

Abstract

The containers (1) are arranged one after the other on an endless belt (2) which is arranged horizontally. The height (h) and/or transverse width (a) of each new container is measured as it arrives. The position of the adhesion equipment (6) and application equipment (7) is regulated. The regulation of the positions of adhesion equipment and application equipment is made according to the measured dimensions of the containers as they arrive. They are positioned o as to be as close as possible to the upper edge of each containers and/or to follow the variations in the transverse dimension (a) of each container.

Description

The present invention relates to a method and a machine for automatic bonding of a heat-shrinkable plastic film on the bottom a rigid container open at its upper part and in section horizontal rectangular or square.

For the shipment of various product groups corresponding at different commands, we are using more and more containers of cardboard or similar materials, such as cases American, half American boxes, trays, etc ... on the bottom of which is glued the central part of a stretch of film heat-shrinkable plastic, the end portions of which are left free to be folded over the grouped products in the container after the preparation of an order. After placing the product group in the container, the latter is passed through a shrink tunnel and the film plastic then shrinks on the products while holding them firmly in place inside the container, which avoids having use of additional wedging elements.

The object of the present invention is to provide a method and a machine which allow to produce, at a high rate, order preparation packaging in large series, in automatically adapting to variations in height and / or horizontal section of successive containers.

To this end, this automatic film bonding process heat shrink plastic on the bottom of an open rigid container at its upper part and with rectangular horizontal section or square, is characterized in that the containers are moved, one to the other following the others, on an endless transporter extending longitudinally, for each new container arriving, we measure its height and / or its dimension in the transverse direction, that is to say perpendicular to the direction of advancement of the containers on the transporter, we then adjust, from the height measurement and / or the transverse dimension of each container, the position vertical and / or transverse extension of a gluing device and a device for applying the plastic film according to the corresponding dimensions of each container so as to place these devices as close as possible to the top edge of each containing and / or following variations in the transverse dimension of each container.

The invention also relates to a gluing machine automatic heat shrinkable plastic film on the bottom of a rigid container open at the top and in section horizontal rectangular or square, with a conveyor without horizontal end intermittently driven, a waiting station at the location of the upstream end part of the transporter on which successive containers are placed and, downstream of this item waiting, a film application station at the top which is located a device for applying a section of film thermoplastic on the bottom of each container, characterized in that it comprises, between the waiting station and the application station of the film, a gluing device for projecting glue, from the top, on the bottom of each container, during longitudinal displacement between the two stations, means for put and hold the containers in position on the transporter, in such a way that one of their longitudinal walls is always located in the same vertical and longitudinal reference plane, means for measuring the height and / or the transverse dimension of each container at the waiting station and means for adjust the vertical position and / or the transverse extension of the gluing device and film application device plastic depending on height and / or size transverse of each container so as to place these two devices as close as possible to the top edge of each container, whatever its height, and / or to be made correspond the transverse extension of the two devices gluing and applying the film to the transverse dimension of each container.

• La figure 1 est une vue en coupe verticale et longitudinale schématique d'une machine suivant l'invention et d'un contenant avant collage d'un film thermoplastique sur son fond, au cours de l'étape de départ d'un cycle de la machine.
• La figure 2 est une vue en coupe verticale et longitudinale schématique illustrant le contenant en cours d'encollage.
• La figure 3 est une vue en coupe verticale et transversale schématique illustrant la phase de tirage transversal du film.
• La figure 4 est une vue en coupe verticale et longitudinale schématique de la machine illustrant le contenant arrivé au poste d'application du film.
• La figure 5 est une vue en coupe verticale et transversale illustrant le poste d'application du film après tirage transversal complet du film au-dessus du contenant.
• La figure 6 est une vue en coupe verticale et longitudinale schématique de la machine illustrant le pressage du film sur le fond encollé du contenant.
• La figure 7 est une vue en coupe verticale et transversale schématique du poste d'application du film pendant le pressage du film.
• La figure 8 est une vue en coupe verticale et longitudinale schématique du contenant libéré après pressage du film sur son fond encollé.
• La figure 9 est une vue en coupe verticale et transversale schématique du poste d'application du film après le pressage du film et la libération du contenant.
• La figure 10 est une vue en coupe verticale et longitudinale simplifiée d'une forme d'exécution d'une machine suivant la présente invention, opérant sur des contenants de différentes hauteurs et/ou sections horizontales.
• La figure 11 est une vue en coupe verticale et transversale faite suivant la ligne XI-XI de la figure 10.
• La figure 12 est une vue en coupe verticale et transversale schématique d'une tête de pressage extensible réglée pour un contenant de petite dimension transversale.
• La figure 13 est une vue en coupe verticale et transversale schématique de la tête de pressage réglée pour un contenant de grande dimension transversale.

Various embodiments of the present invention will be described below, by way of non-limiting examples, with reference to the appended drawings in which:

• Figure 1 is a schematic vertical and longitudinal sectional view of a machine according to the invention and of a container before gluing of a thermoplastic film on its bottom, during the starting step of a cycle of the machine.
• Figure 2 is a schematic vertical and longitudinal sectional view illustrating the container during gluing.
• Figure 3 is a schematic vertical and cross sectional view illustrating the transverse film drawing phase.
• Figure 4 is a schematic vertical and longitudinal sectional view of the machine illustrating the container arrived at the film application station.
• FIG. 5 is a view in vertical and transverse section illustrating the station for applying the film after complete transverse drawing of the film above the container.
• Figure 6 is a schematic vertical and longitudinal sectional view of the machine illustrating the pressing of the film on the glued bottom of the container.
• Figure 7 is a schematic vertical and cross-sectional view of the film application station during film pressing.
• Figure 8 is a schematic vertical and longitudinal sectional view of the container released after pressing the film on its glued bottom.
• Figure 9 is a schematic vertical and cross-sectional view of the film application station after pressing the film and releasing the container.
• Figure 10 is a simplified vertical and longitudinal sectional view of an embodiment of a machine according to the present invention, operating on containers of different heights and / or horizontal sections.
• FIG. 11 is a view in vertical and transverse section taken along the line XI-XI of FIG. 10.
• Figure 12 is a schematic vertical and cross-sectional view of an expandable pressing head adjusted for a container of small transverse dimension.
• Figure 13 is a schematic vertical and cross sectional view of the pressing head adjusted for a container of large transverse dimension.

We will first describe, with reference to Figures 1 to 9, the different steps of the automatic bonding process of a heat-shrinkable plastic film on the bottom of a rigid container 1 open at its upper part and with a rectangular horizontal section or square, this process being implemented in a machine shown very schematically. In Figure 1 are shown several containers 1 having a variable height h and a horizontal section having a variable transverse dimension a and a longitudinal dimension b . In the following description, the expression "longitudinal" should be understood as referring to the longitudinal direction of movement, from left to right in the figures of the drawing, of the containers on a horizontal and longitudinal conveyor 2 of any suitable type , the expression "transverse" referring to the direction perpendicular to the previous one. In other words, each container 1 is placed, by all appropriate means, on the upstream or left end portion A of the endless conveyor 2 so that its "transverse" dimension a extends in the "transverse" direction of the conveyor 2. The conveyor 2 is driven in an intermittent movement and each container 1 is placed on the upstream end part A of the conveyor 2 while stopped, constituting a waiting station. While the container 1 is at a standstill at the waiting station or before arriving at this station, a measurement is made of its height h and of its cross section and more particularly of its transverse dimension a. This measurement step is represented by a block 3 in FIG. 1. The result of these measurements is transmitted to a general control device 4 which acts on a device 5 controlling the adjustment of the vertical position and / or of the transverse extension a sizing device 6 and a device 7 for applying the film. The film application device 7 is located above the extreme downstream part of the conveyor 2, defining a film application station B. The sizing device 6 is located between the waiting station A and the film application station B. The sizing device 6 can be independent of the film application device 7 or associated with it.

During the first step of the method according to the present invention, that is to say while the container 1 is stationary at the stand A, it is automatically adjusted, from the measurements of the height h and / or the transverse dimension a of the container 1, the vertical position of the devices 6 and 7, so that they are located as close as possible to the upper edge of the container 1, and / or the transverse extension of these devices so that it corresponds to the transverse dimension a of the container.

Once the appropriate settings for devices 6 and 7 done, we go to the second step of the process which consists of spray glue on the bottom of container 1 using the device 6 which has glue nozzles directed downwards.

The gluing step can be carried out by causing a longitudinal movement of the gluing device 6 above the container 1 kept stationary on the conveyor 2. According to a variant, gluing can take place, as illustrated on Figure 2, during the movement of the container 1 of the station waiting A to the film application station B. In this case, the gluing device 6 has a fixed longitudinal position and it can then be associated with the film application device 7, being mounted on the upstream or left side of it, so that it can be moved vertically together with the device 7.

Figure 3 schematically illustrates the drawing in the direction transverse, by means of a movable clamp 8, of the thermoplastic film retractable 9 which is unwound from a side reel 11 located at the film application station B. The movable clamp 8 to transverse movement is part of the device 7 for applying the film, as will be described in more detail below.

Figures 4 and 5 show the container 1 arrived at the film application station B and stopped at this station, before applying the film 9 on its glued bottom. Longitudinal glue strips 12 which have been previously projected onto the bottom of the container 1, by the sizing device 6, have been indicated in these figures. In FIG. 5, it can be seen that the film 9 has been drawn transversely over the containing 1 and beyond it, over a variable length which depends on its height h and / or its transverse dimension a . While the container 1 with a glued bottom is at station B, a new container 1, of height h and / or of transverse dimension a identical or different, is placed at the waiting station A.

The next step in the process consists of pressing the film 9 inside the container 1, so as to apply it against its bottom 1, as illustrated in FIGS. 6 and 7. At this effect, a pressing head 13, movable vertically, which is part of the film application device 7 and which is located above of this film, is lowered so as to enter the container 1 and to apply the film 9 under pressure against its bottom, for one sufficient period of time, of the order of 2 seconds, for example to ensure effective bonding. During the end of pressing, a cutting device 14 is actuated to separate the film section which is stuck inside the container 1, of the supply reel 11.

After the expiration of the period of time scheduled for the pressing, the pressing head 13 is moved upwardly to be released from container 1, as shown in the Figures 8 and 9. Container 1, provided with the film section heat-shrinkable 9 the central part of which is glued to the bottom of the containing 1 and whose end parts are free, can then be evacuated as a result of restarting the transporter 2.

We will now describe, with reference to FIGS. 10 to 13, a non-limiting embodiment of a machine implementing the process according to the present invention.

In the embodiment shown in Figures 10 and 11, the endless transporter 2 which causes the displacement successive longitudinal of the various containers 1, includes a path horizontal transfer 15 of which the upstream end part is made up by horizontal and transverse rollers 16 and the downstream part by a smooth plate 17. The various containers 1 are moved on the rollers 16 and on the support plate 17 by sliding on them and they are driven by transverse push bars 18 attached at their ends to endless chains 19 extending longitudinally, on either side of the transfer path 15, and driven by a motor 21. The motor 21 is supplied in a way intermittent and the spacing between the push bars 18 is chosen in such a way that during each walking period of the motor 21, each container 1 is driven from the waiting station A to film B application station or from this latter station on a evacuation conveyor located in the extension of carrier 2 and not shown.

Upstream of intermittent conveyor 2 and at alignment with this is a selection station S comprising a feed conveyor 22 of any suitable type, on which are placed the containers arriving one after the other. This conveyor 22 is located at a level slightly lower than that of the support rollers 16 of the endless conveyor 2 so that the upstream end roller 16 forms a stop to stop each new container 1 arriving, thus causing an accumulation containers 1, one after the other, on the conveyor 22. A selector 23, fitted with an up and down system controlled by a jack 24, allows, at the appropriate time in the cycle of the machine, to slightly lift the downstream part of the first containing 1 found in the series of containers waiting on the feed conveyor 22, and pass it on the bench rollers 16, to place it at waiting station A.

At the selection station S, as well as at stations A and B there are, on one of the longitudinal sides of the conveyors, in this case on the right side in FIG. 11, fixed longitudinal guides 25, aligned, defining a vertical and longitudinal reference plane P and against which a longitudinal wall of the successive containers 1 is pressed. At the selection station there is also a side jogging bar 26 which is located opposite the corresponding fixed longitudinal guide 25, that is to say on the left side of the machine, and which is movable transversely, on slides 27, under the control of a jack 28. When this jack 28 is actuated in the appropriate direction, the jogging bar 26 is moved transversely towards the fixed guide 25 and it presses the container 1 located between them against the fixed guide 25 so that its right longitudinal wall is in the longitudinal reference plane P defined by the fixed guides 25. The magnitude of the displacement of the side jogging bar 26 is also used, in this embodiment of the machine, to measure the transverse dimension of each container 1. the extent of the transverse dimension has thus taken is transmitted to the general control apparatus 4 (Figure 1) and the latter controls the traverse along guides itudinaux mobiles 29,31, which are located respectively on the left side of the machine, that is to say opposite the fixed guides 25, at the position of stations A and B, so that these guides 29.31 mobile, serving the aligning bar 26, come to align longitudinally of the distance has opposed stationary guides 25, which corresponds to the transverse dimension of the container 1 in question.

The longitudinal guides 29, 31 are mounted mobile on respective cross slides 32.33 and their movements are controlled by respective transverse cylinders 34.35.

The height h of each container 1 is measured, at the standby station A, for example by means of a set of superimposed photoelectric cells 36 and arranged above the conveyor 2, on one side of the latter. These photoelectric cells 36 or any other equivalent means are connected to the general control device 4 to cause the automatic adjustment of the vertical position of the device 7 for applying the film as a function of the height h of each container 1.

The film application station B will now be described in detail. The device 7 comprises, in addition to the pressing head 13, a horizontal frame or apron 37 which is mounted vertically adjustable on the frame 38 of the machine. To this end, the right longitudinal side (Figure 11) of the frame 37 is attached to a pair of vertical endless chains 39, mounted movably on the frame 38 and driven by a motor 41 so that the frame 37 can be moved vertically and placed in a vertical position close to the upper edge of each container 1 located under it at station B, whatever the height h of this container.

The frame 37 carries several mobile assemblies. Firstly, in this non-limiting embodiment, it carries, on its upstream transverse side, nozzles forming part of the sizing device 6, the longitudinal position of which is fixed. More particularly, the sizing device comprises at least one vertical nozzle 42 and preferably two nozzles which are fixedly mounted on the frame, on the right side in FIG. 11, that is to say on the side of the vertical reference plane P, so as to project, on the bottom of each container 1, bearing on the fixed reference guide 25, during its longitudinal displacement from station A to station B, one or two strips of longitudinal adhesive 12. For this purpose, the axes fixed nozzles 42 are slightly offset towards the inside, relative to the fixed guides 25, so as to project their jets of glue at the appropriate places on the bottom of each container 1. The sizing device 6 also comprises, at the same level than the fixed nozzle or nozzles 42, one or two opposite nozzles which are mounted movable transversely on the frame 37, under the control of at least one jack 44. The transverse position of the nozzle 43 or of each nozzle 43 can thus be adjusted in function tion of the transverse dimension a of the container 1 located under the frame 37. The nozzles 42, 43 are supplied with adhesive under pressure, during the longitudinal movement of each container 1 beneath them, under the control of a photoelectric cell detecting the passage of the container, the duration of the projection of the glue jets being approximately 2 seconds.

The frame 37 also carries means which allow the transverse drawing of the plastic film 9 above the container 1. These means comprise the movable longitudinal clamp 8 which extends longitudinally and which is moved transversely by transverse endless chains 45 mounted mobile on the frame 37 and driven by a motor 46. The frame 37 also carries, in its straight part, that is to say on the side of the vertical reference plane P, a longitudinal clamp 47 in a fixed position. The opening and mobile clamp 8 and fixed clamp 47 are closed by cylinders themselves actuated by the control unit general 4 (figure 1).

The plastic film 9 is unwound from the reel 11 which is located on the right side of the machine, at station B, which is driven in rotation by a motor 48. The unwound film 9 passes through a hauling device 49 which comprises fixed rollers 51 and movable rollers 52 carried by an articulated arm 53 pivoting around an axis 54. After having passed through the device hauling 49, the film is engaged in the fixed clamp 47. The unwinding of the coil 11 takes place between two cycles, while the end of the film 9 is held by the fixed clamp 47 closed. The arm articulated 53, mechanically controlled, rotates towards the low by causing a certain length of film 9 to unwind and constituting a reserve of available film. This allows, when the introduction of the film 9, by the pressing head 13, into the containing 1, to the arm 53 of the hauling device 49 which is then made free without constraint, to return to the high position under the effect of the traction of the film 9, as it is represented on the figure 11.

The frame 37 also carries the cutting device 14. This cutting device 14 includes a vertical knife 55 which is located near the fixed clamp 47, inwards. The knife 55 is secured to an endless chain 56 extending horizontally and longitudinally, driven by a motor 57, so that it can cut the film 9, in the transverse direction of this film, during the end pressing on the bottom of container 1.

As previously indicated, the device 7 film application also has, above the opening central of the frame 37, the pressing head 13 which is mounted movable vertically on the frame 38 of the machine. This pressing head 13 is attached to a vertical arm 58 sliding in a slide vertical 59 secured to a bracket 61. This bracket 61 is attached to vertical endless chains 62 which are carried by the frame 38 and which are driven by a motor 63. The starting of the motor 63, in the appropriate direction, by the control unit general 4, causes the vertical movement of the pressing head 13 to lower it, through the central opening of the frame 37, to the interior of the container 1, in order to press the film 9 on its bottom glued, and to make it rise, after pressing, above the frame 37, as shown in FIG. 11.

The pressing head may have a constant transverse dimension, if the transverse dimension of the containers does not vary, or otherwise vary if the machine works with containers to transverse dimension is variable. In the latter case the pressing head 13 is extendable in the transverse direction and a non-limiting embodiment of this head is shown in FIGS. 12 and 13. The pressing head 13 comprises, at its lower part, two elements of square shaped pressing, namely a fixed pressing element 64 and a transversely movable pressing element 65, each comprising a respective vertical wing 64 a , 65 a and a respective horizontal wing 64 b , 65 b . Each of the horizontal wings 64b, 65b which extend towards one another, of the pressing elements 64, 65 is advantageously provided, on its underside, with a layer of elastic material 66, such as a layer of foam. The movable pressing element 65 is moved transversely under the control of a jack 67 by means of a connection mechanism 68 with pivoting rods and slides, as shown in FIGS. 12 and 13. L actuation of the cylinder 67, in one direction or the other, makes it possible to lengthen or shorten the pressing head 13 in the transverse direction, in order to adapt it to the transverse dimension a of the container 1. During the descent of the pressing head 13 inside the container 1, the horizontal wings 64b, 65b, are applied, with the lower layers of foam 66 which they carry, on the film 9 extending horizontally and they drives down to the bottom of the container 1. When the wings 64 b , 65 b reach the bottom of the container 1, the head 13 is immobilized in the pressing position while the bracket 61 continues its downward travel. The wings 64b, 65b exert pressure on the film 9 which is applied to the strips of glue 12 previously deposited on the bottom of the container.

In the case where the container 1 is a cardboard box with internal flaps of the bottom not contiguous, the layers of foam 66 advantageously have, in their median parts, transverse bosses 66 a (FIG. 10) whose width corresponds substantially to the distance between the edges of the internal flaps, in order to be able to effectively press the film also in the space between the edges of the internal flaps.

The machine also advantageously includes blow guns air which are associated with the film application device 7 and which allow the parts to be folded down inside the container free extremes of the thermoplastic film section of which only the central part is glued to the bottom.

The machine according to the invention achieves a rate high production of around 660 to 720 containers per hour, or from 10 to 12 containers per minute.

Claims (14)

Method for automatically bonding a heat-shrinkable plastic film (9) to the bottom of a rigid container (1) open at its upper part and with a rectangular or square horizontal section, characterized in that the containers are moved, one to the other following the others, on an endless conveyor (2) extending longitudinally, we measure, for each new container (1) arriving, its height ( h ) and / or its dimension ( a ) in the transverse direction, c ' that is to say perpendicular to the direction of advancement of the containers (1) on the conveyor (2), we then adjust, from the measurement of the height ( h ) and / or the transverse dimension ( a ) of each container, the vertical position and / or the transverse extension of a sizing device (6) and a device (7) for applying the plastic film as a function of the corresponding dimensions of each container (1) so as to place these devices as close as possible to the top edge of each container and / or to follow the variations in the transverse dimension (a) of each container (1). Method according to Claim 1, characterized in that the bottom of each container (1) is glued by causing a relative longitudinal displacement between the container (1) and the sizing device (6) and by spraying glue, starting from from the top, during this movement, on the bottom of each container (1) so as to form on this bottom longitudinal strips of glue (12). Automatic gluing machine for a heat-shrinkable plastic film (9) on the bottom of a rigid container (1) open at its upper part and with a rectangular or square horizontal section, comprising an endless horizontal conveyor (2) driven intermittently, a waiting station (A) at the location of the extreme upstream part of the transporter on which the successive containers (1) are placed and, downstream of this waiting station (A), a station (B) of applying the film to the upper part of which is located a device (7) for applying a section of thermoplastic film (9) to the bottom of each container (1), characterized in that it comprises, between the station d waiting (A) and the station (B) for applying the film, a gluing device (6) for projecting glue, from the top, onto the bottom of each container (1), during its longitudinal displacement between the two stations (A, B), means (26, 29, 31) for placing and holding the containers in position s (1), on the conveyor (2), so that one of their longitudinal walls is always situated in the same vertical and longitudinal reference plane (P), means (36, 26) for measuring the height ( h ) and / or the transverse dimension ( a ) of each container (1) located at the waiting station (A) and means (5) for adjusting the vertical position and / or the transverse extension of the gluing (6) and the device (7) for applying the plastic film as a function of the height ( h ) and / or the transverse dimension ( a ) of each container (1) so as to place these two devices (6, 7) as close as possible to the upper edge of each container (1), whatever the height thereof, and / or to make the transverse extension of the two sizing devices (6) and application of the film (7) at the transverse dimension ( a ) of each container (1). Machine according to claim 3 characterized in that it comprises, upstream of the waiting station (A), a selection station (5) comprising a conveyor (22) for bringing the containers (1), aligned with the conveyor endless (2) and located at a level lower than that of the endless conveyor (2), a side jogging bar (26), located on a first side of the feed conveyor (22), movable transversely under the control of a jack (28), and cooperating with a fixed longitudinal guide (25) disposed on the second opposite side of the conveyor (22) and defining the vertical reference plane (P), the magnitude of the displacement of the side jogging bar (26) for measuring the transverse dimension (a) of each container (1), and means (23,24) for passing, one after the other, the containers (1), accumulated on the conveyor d brought (22) to the waiting station (A) on the endless conveyor (2). Machine according to Claim 4, characterized in that it comprises, at the location of the waiting station (A) and the film application station (B), respective mobile longitudinal guides (29, 31), located from the first side of the endless conveyor (2), and on the second opposite side, fixed longitudinal guides (25) aligned along the vertical and longitudinal reference plane (P), the positions of the mobile guides (29,31) of the stations (A, B) being slaved to the position of the jogging bar (26) so that the movable guides (29,31) are aligned longitudinally at the distance ( a ) from the opposite fixed guides (25), which corresponds to the transverse dimension ( a ) of each container (1). Machine according to any one of Claims 3 to 5, characterized in that the waiting station (A) comprises means for measuring the height ( h ) of each container, such as for example a set of superimposed photoelectric cells (36) which are arranged above the conveyor (2), on one side thereof. Machine according to any one of Claims 3 to 6, characterized in that the film application station (B) comprises, above the endless conveyor (2), a horizontal frame or apron (37) which is mounted adjustable vertically on the frame (38) of the machine and, above the frame (37), a horizontal pressing head (13) mounted vertically movable and able to pass through the central opening of the frame (37). Machine according to claim 7 characterized in that the frame (37) carries, on its upstream transverse side, vertical nozzles (42,43) forming part of the gluing device (6) and directed downwards. Machine according to claim 8 characterized in that at least one vertical nozzle (42) is fixedly mounted on the frame, on the side of the vertical reference plane (P), and at least one opposite vertical nozzle (43) is mounted movable transversely on the frame (37), under the control of at least one jack (44), so that its transverse position can be adjusted as a function of the transverse dimension ( a ) of the container (1) located under the frame (37 ). Machine according to any one of Claims 7 to 9 characterized in that the frame (37) carries means which allow transversely pull the plastic film (9) over each container (1), these means comprising a first clamp longitudinal (47) fixed position, located on the side of the vertical plane reference (P), a second longitudinal clamp (8) which is mounted movable transversely on the frame (37), opposite the first fixed clamp (47), opening and closing of the first clamp mobile (8) and the second fixed clamp (47) being caused by cylinders, and the plastic film (9) which is unwound from a reel lateral film (11), passing through a device for hauling (49), is engaged in the first fixed clamp (47) to be able to be grasped, at its end, by the second movable clamp (8). Machine according to claim 10 characterized in that the frame (37) carries a device (14) for cutting the plastic film (9), this device comprising a vertical knife (55) which is located near the first fixed clamp (47 ), inward, and which is integral with an endless chain (56) extending horizontally and longitudinally and driven by a motor (57) so as to be able to cut the film (9), in the transverse direction of this film, during the end of its pressing on the bottom of a container (1). Machine according to any one of Claims 7 to 11, characterized in that the pressing head (13) is secured to a vertical arm (58) sliding in a vertical slide (59) secured to a bracket (61) which is attached to vertical endless chains (62) which are carried by the frame (38) and which are driven by a motor (63), so as to lower the pressing head (13), through the central opening of the frame (37), inside the container (1), to press the film (9) on its glued bottom, and to make it rise, after pressing, above the frame (37). Machine according to claim 12 characterized in that the pressing head (13), extendable in the transverse direction, comprises, at its lower part, two pressing elements in the form of a square, namely a fixed pressing element (64) and a transversely movable pressing element (65), each comprising a respective vertical wing (64 a , 65 a ) and a respective horizontal wing (64 b , 65 b ), a jack (67) and a connection mechanism (68) to pivoting and sliding rods for horizontally and transversely displacing the movable pressing element (65), in order to lengthen or shorten the pressing head (13) in the transverse direction in order to adapt it to the transverse dimension ( a ) a container (1). Machine according to Claim 13, characterized in that the horizontal flanges (64 b, 65 b) of the respective pressing elements (64,65) bear on their lower faces, the elastic material layers (66), such as layers of foam, and the foam layer (66) optionally present in their middle portions, transverse projections (66 a), in case the container (1) is a cardboard box with inner flaps of the bottom non-contiguous, the bosses transverse (66 a ) having a width corresponding substantially to the distance between the edges of the internal flaps.

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