EP1422143A1 - Apparatus for wrapping a load by means of a plastic foil - Google Patents

Abstract

The machine for wrapping a load (CH) in a plastic film has guide rollers to orient the film for full coverage of the load side and upper surfaces (16,17). The rollers include a pair (15) adjacent to the load and a return roller (28) at an angle. The assembly is mounted to tilt between horizontal and vertical positions. The feed reel (11) and the guide rollers can be mounted on a carriage (CM). The load is mounted on a turntable (13).

Description

Technical field of the invention

The invention relates to a machine for packaging a load by means of a film. made of flexible plastic, comprising a turntable supporting the load, means for supporting a film storage reel, means for film guide inserted between the reel and the turntable, to cover without discontinuity by wrapping the lateral face and the upper horizontal face of the load, and means for translational movement between a low position and a high position, separated from each other by an adjustable vertical stroke in depending on the height of the load.

State of the art

A wrapping machine for wrapping a shaped palletized load parallelepiped is known from document EP-A-0 467 729, in which the same film is used to obtain a total covering of the four planes of the face lateral, and from the upper horizontal face. We rotate the storage reel film in the horizontal position at the start of the packaging cycle, when covering of the upper face, and at the end of the cycle to perform the welding. The coil is actuated on the other hand to pivot to the vertical position for wrap the side panel. Stop means are necessary to ensure positive locking of the spool axis in the two positions of operation. In addition to this double orthogonal pivoting of the coil, a vertical sliding movement thanks to a mobile carriage on which is mounted the coil. Such kinematics is complicated, and does not allow use large capacity film reels. The pivoting mounting of the reel on the carriage makes it difficult to load the reel and pass the film packaging. The pre-stretching device must also be pivotally mounted to follow the reel.

The document EP-A-0 522 928 describes a wrapping machine by wrapping, in which the means supporting the coil comprise a vertical mast and a mobile carriage mounted vertically sliding and pivoting about an axis. The coil thus describes a double movement of sliding and rotation along a ring surrounding the table.

To deposit a packaging film on the vertical planes of the lateral face, and on the upper side of a palletized load, we also know the technique of cover with stretch or heat shrink film. This technique is more difficult to implement than that of wrapping.

Document US-A-4 409 776 relates to a packaging machine by wrapping a palletized load with a film having a sticky side. A first layer of film is applied to the load, the non-sticky side directed towards the load. A 180 ° turn of the reel orients the sticky side of the film on the reel opposite the sticky side of the first layer of film wrapped on the load. The wrapping of the second layer ensures adhesion of the two layers of film.

Document US 5,140,798 describes a wrapping machine by wrapping of a palletized load, in which the coil extends vertically, with the pivoting guide device directly receiving the film coming from the coil. The stretch film used has a sticky side to obtain good cohesion by superimposing the layers. Such a device can cause a uncontrolled conformation of the film between the reel and the application device, the guiding of the film not being positively controlled during pivoting of the device application. This results in a high risk of the film sticking to itself during the pivoting movement of the application device.

Subject of the invention

The object of the invention is to remedy the aforementioned drawbacks, and to realize a wrapping machine by wrapping, allowing to increase the rates by the use of a large capacity film reel, regardless of the reel layout, and precisely apply the film flat on top load with a minimum of wrinkling to guarantee a good seal.

The device according to the invention is characterized in that the film is brought to a multidirectional guidance device grouping a pair of rollers guide and an inclined return device, the assembly being mounted to tilt around a tilt axis between a horizontal position and a position vertical.

The presence of this multidirectional guidance system and the deflection device between the reel and the plate, allows the same film to be used continuously for the covering of the lateral face and the upper face of the load, in always keeping the coil in the same direction, without movement of failover.

According to a preferred embodiment, the film storage reel and the multidirectional guidance device are mounted on a mobile carriage constituting said means for translational movement. The guidance system multidirectional comprises for example a pair of non-motorized rollers between which the film passes.

The film storage reel can also be fixed by extending horizontally or vertically near the ground. The film is then brought to the multidirectional guidance via an accumulator device placed before the return device.

In the case of a machine using stretch film, the film can be wound on the spool in a pre-stretched state. It is also possible to use a film pre-stretching device arranged at the exit of the reel, and comprising a couple of motorized rollers allowing the film to be unwound downstream at a higher speed than upstream. The stretched film flow is advantageously controlled by means of speed and / or force measurement to control the force of application of the film on the load.

According to another alternative embodiment, the device for pre-stretching the film is associated with the multidirectional guidance system.

In the case of a machine using heat-shrinkable film, the load wrapped by wrapping on the tray, then goes to a post shrinkage containing heating means for heat shrinking the charge film.

Brief description of the drawings

• la figure 1 est une vue schématique en perspective d'une machine d'emballage par banderolage selon l'invention, la bobine pouvant se déplacer parallèlement à l'axe de rotation de la charge ;
• les figures 2 à 12 illustrent les étapes successives de fonctionnement de la machine d'emballage de la figure 1 ;
• la figure 13 montre une vue similaire de la figure 1, illustrant une variante de réalisation à bobine fixe et plateau tournant ;
• la figure 14 représente une vue partielle de la figure 13 dans la phase de recouvrement de la face horizontale supérieure de la charge.

Other advantages and characteristics will emerge more clearly from the description which follows of an embodiment of the invention given by way of nonlimiting example, and represented in the appended drawings, in which:

• Figure 1 is a schematic perspective view of a wrapping machine by wrapping according to the invention, the coil being able to move parallel to the axis of rotation of the load;
• Figures 2 to 12 illustrate the successive stages of operation of the packaging machine of Figure 1;
• Figure 13 shows a similar view of Figure 1, illustrating an alternative embodiment with fixed coil and turntable;
• Figure 14 shows a partial view of Figure 13 in the covering phase of the upper horizontal face of the load.

Description of a preferred embodiment.

With reference to FIG. 1, a machine for packaging a palletized CH load, includes a reel 11 for storing a flexible film 12, a turntable 13 serving as a support for the CH load of parallelepiped shape, means actuating 14 in rotation of the plate 13, and film orientation means 12 to cover by side wrapping the side face 16 and the horizontal surface 17 higher of the CH load.

The lateral face 16 of the load CH comprises four planes 16a, 16b, 16c, 16d arranged in vertical planes two by two parallel, and delimiting the four corners of the vertical edges 19 parallel to the axis of rotation 20 of the load CH.

The film 12 used is a width of stretchable or heat-shrinkable plastic, in particular in polyethylene, said width being wound on the reel 11 according to a horizontal axis orthogonal to the axis of rotation 20 of the load CH. For exemple, the width of the width may be between 500mm and 1500mm, while the height of the load CH is generally greater than said width.

In the case of a stretch film 12, the pre-stretching takes place before it is deposited on the CH load, for example by means of a film directly wound in the pre-stretched state (case of the example illustrated in figure 1).

It is also possible to obtain pre-stretching via a couple of motorized or non-motorized rollers at the output of the coil 11, so that the film 12 is unwound downstream at a speed greater than the speed upstream (see figure 13).

The means for orienting the film 12 after unwinding the reel 11 are constituted according to the invention by a multidirectional guidance system 15 grouping a pair of guide rollers 21 between which the film passes, and a return device 28 at 45 °, the assembly being interposed between the coil 11 and the turntable 13, and tiltably mounted around a horizontal axis 22 of so as to occupy either a horizontal position or a vertical position. The return device 28 at 45 ° is interposed between the coil 11 and the two rollers guide 21 so as to position the width of film 12 parallel to the lateral surface 16 of the load CH.

The coil 11, the deflection device 28 and the pair of guide rollers 21 are carried by a movable CM carriage capable of moving in the direction vertical between a low position (Figures 2 and 3) and an extreme high position (figure 5). The vertical stroke of the CM carriage between the two extreme positions is adjustable according to the height of the CH load.

The turntable 13 includes a retaining clamp 23 capable of retaining a part end of the film 12 deposited at the base of the load CH, said clamp being able be additionally equipped with welding and film cutting means to ensure automatic operation of a production line.

The successive stages of operation of the packaging machine 10 according to the invention are illustrated in FIGS. 2 to 12, the same film being used at the same time for continuously covering the upper face 17 and the face lateral 16 of the CH load:

In the first step of starting the cycle illustrated in FIG. 2, the load C H is deposited on the plate 13, which is rotated in the direction of the arrow F1 by the actuating means 14, constituted by way of example by a gearmotor. The end of the film 12 is maintained during the movement of rotation of the load CH by the retaining clamp 23 being in the closed state. The CM carriage supporting the return device 28 and the guide rollers 21 is placed in the lowered position, so as to start the wrapping of the face lateral 16 from the base of the load CH. The guide rollers 21 and the return device 28 are pivoted by a quarter turn in the direction of arrow F2 towards the horizontal position, allowing the start of flat winding of the film 12 on a reduced width of the different planes 16b, 16c, 16d.

In Figure 3, an upward movement of the CM carriage drives the rollers guide 21 and the upward deflection device 28 authorizing the deposition of the film on the faces 16a, 16b without trapping the retaining clamp 23. Next, a downward movement of the carriage so as to cover the reduced width of the film, allowing the opening of the clamp 23. The guide rollers 21 and the return device 28 remain in a horizontal position during this first step.

In FIG. 4, the guide rollers 21 and the deflection device 28 are tilted to the vertical position (arrow F3) to position the film 12 parallel to the lateral face 16 before it is deposited on the load CH. The cart C M slides to the high position (arrow F4), until the guide rollers 21 slightly exceed the horizontal plane of the upper face 17 of the load CH. During this vertical sliding movement of the carriage CM, the film 12 envelops the entire lateral surface 16 of the load CH following the rotation of the plate 13 in the direction of arrow F1.

Referring to Figure 5, the guide rollers 21 and the deflection device 28 rotate to the horizontal position (arrow F5) with an upward movement and lowering of the CM carriage intended to apply the film 12 to cover part of the upper face 17.

In FIG. 6, the guide rollers 21 and the deflection device 28 pivot in opposite direction to the vertical position, while the CM carriage remains in position high. The film 12 is then ready to be deposited in parallel on one of the planes of the side face 16.

During these operations, the load CH rotates continuously with or without variation of speed.

With reference to FIGS. 7 and 8, maneuvers identical to those are carried out previously described for FIGS. 5 and 6 so as to cover another part of the upper face 17. The carriage CM for supporting the coil 11, guide rollers 21, and of the deflection device 28, remains in the high position during these operations. These operations can be repeated to ensure partial or total sealing of the face 17 of the CH load.

FIG. 9 represents the wrapping operation of the planes of the lateral face 16, by sliding the CM carriage towards the low position, the guide rollers 21 and the return device 28 remaining held in the vertical position.

In FIG. 10, the tilting of the guide rollers 21 and of the return 28 to the horizontal position allows pleating of the width at one predetermined height of the base, for example between 3 cm and 20 cm. The open clamp 23 recovers this pleated part of the film during the continued rotation of the CH load on the plate 13.

In FIG. 11, the rotation of the plate 13 is stopped, without modifying the position of the CM carriage and guide rollers 21. Closing of the retaining clamp 23 then allows the film strip 12 to be cut after having welded the terminal part charged to CH.

In FIG. 12, the load CH packaged on its five faces, is released from the plate 13, which is immobilized in rotation. The film 12 held in the clamp 23, is in waiting for a new packaging cycle.

On the plate 13 can be mounted a handling table equipped with organs motorized rolling, transmission chains or a conveyor belt to automatically route the packaged CH load from an upstream station or evacuate it to a downstream station.

In the alternative embodiment of FIG. 13, the reel 11 for storing the film 12 is fixed by being arranged with a horizontal axis at ground level. At the output of the coil 11 is a film pre-stretching device 24 for pre-stretching the film from the coil 11 before passing it through an accumulator device 25. The pre-stretching device 24 of a well-known type, comprises rollers 26 between which passes the film 12, the rollers 26 being driven at speeds circumferential by a geared motor mechanism 27 associated with a couple of pinions 29, 30 of different diameters. The accumulator device 25 includes a series of rollers spaced at various levels to store a certain length of pre-stretched film 12, allowing vertical movement of the carriage CM regardless of the height of the CH load. The return device 28 to 45 ° is interposed between the accumulator device 25 and the two guide rollers 21 so as to position the width of film 12 parallel to the lateral surface 16 of the CH load. The two accumulator and return device 25, 28 can move in vertical translation to perform a helical wrapping around of the CH load. The coil 11 and the pre-stretching device 24 remain subject on the ground, or on a fixed frame.

In FIG. 14, the deflection device 28 at 45 ° and the guide rollers 21 tilt (arrow F7) relative to a horizontal axis to perform the recovery of the upper face 17. The rest of the packaging cycle is similar to that described previously.

According to another variant (not shown), the film pre-stretching device can be mounted on the movable carriage CM of Figure 1, so as to move with the coil 11 between the low position and the high position.

It is also possible to integrate the pre-stretching device into the multidirectional film guide 15, for example by replacing the rollers 21 free in rotation of FIG. 1 by motorized or not motorized pre-stretching rollers, and rotating at different speeds.

In the case of a heat-shrinkable film, the load wrapped by wrapping on the plate 13, then passes into a retraction station containing a hood or a oven to heat shrink the film on the load CH.

According to another alternative embodiment, the carriage CM can be animated with a rotational movement around the load CH after neutralization of the means actuator 14 making the plate 13 fixed.

Depending on the desired packaging rates, it is also possible to make use of a cart animated with a relative movement of reverse rotation with respect to that of the load tray.

Claims (12)

Machine for packaging a load (CH) by means of a film (12) of flexible plastic material, comprising: a turntable (13) for supporting the load (CH), means for supporting a film storage reel (11), actuating means (14) for rotating the plate (13), guide means (15) of the film interposed between the reel (11) and the turntable (13), to cover the lateral face (16) and the upper horizontal face (17) of the load (CH) without banding , and means for translational movement of the guide means between a low position and a high position, separated from each other by a vertical stroke adjustable as a function of the height of the load (CH), characterized in that the film (12) is brought to a multidirectional guide device (15) grouping together a pair of guide rollers (21) and an inclined return device (28), the assembly being pivotally mounted around a pivot axis (22) between a horizontal position and a vertical position. Packaging machine according to claim 1, characterized in that the film storage reel (11) and the multidirectional guide device (15) are mounted on a mobile carriage (CM) constituting said means for translational movement. Packaging machine according to claim 1, characterized in that the reel (11) has a fixed axis, and is associated with an accumulator device (25) disposed before the return device (28). Packaging machine according to claim 3, characterized in that the accumulator device (25) and the deflection device (28) are movable so as to effect a helical wrapping around the load (CH). Packaging machine according to one of the preceding claims, making use of a stretch film, characterized in that the film (12) is wound on the reel (11) in a pre-stretched state. Packaging machine according to one of Claims 1 to 4, making use of a stretch film, characterized in that a film pre-stretching device (12) is arranged at the exit of the reel (11), and comprises a pair of motorized or non-motorized rollers (26) allowing the film to be unwound downstream at a speed greater than that upstream. Packaging machine according to one of Claims 1 to 4, making use of a stretch film, characterized in that a film pre-stretching device is associated with the multidirectional guide device (15). Packaging machine according to one of the preceding claims, characterized in that the multidirectional guide device (15) comprises a pair of non-motorized rollers (21) between which the film (12) passes. Packaging machine according to one of the preceding claims, characterized in that the deflection device (28) is inclined at 45 °, the spool (11) extending along a horizontal axis relative to the ground. Packaging machine according to one of claims 1 to 8, characterized in that the reel (11) extends vertically in a direction parallel to the axis of rotation of the plate (13). Packaging machine according to claim 2 or 3, characterized in that the carriage (CM) is rotated around the load (CH) after neutralization of the actuating means (14) in rotation. Packaging machine according to claim 2 or 3, characterized in that the carriage (CM) is driven in a relative movement of opposite rotation with respect to that of the plate (13) of the load (CH).

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