ES2279936T3 - PROCEDURE AND DEVICE FOR PLACEMENT OF AN EXTENSIBLE PLASTIC FILM PACKING COVER ON A PALETIZED LOAD. - Google Patents

Abstract

Placement procedure on a palletized load (CM) of a flexible packaging wrap obtained from an extensible film wrap, consisting of: - opening the wrap to establish the volume above the load, - pleating the side parts of the accordion wrap on pleated fingers (12), causing motorized casters (14) to rotate in a first direction of rotation (F1, F2), each finger having an inclination in relation to the vertical direction, - to stretch then the pleated envelope in the horizontal transverse direction to obtain a larger opening than the perimeter of the load (CM) to be packed, - and to move the stretched envelope above the load (CM) in a vertical direction causing progressive unfolding during the sheathing. characterized in that the perimeter reduction around the fingers (12) is limited by a braking and compensation element (26) in the lower part (12A) of each inclined finger to distribute the folds regularly before the transverse stretching phase horizontal.

Description

Procedure and device for placing a plastic sheath wrapping on a load palletized

The invention relates to a method of placement on a palletized load of a flexible sheath of packaging obtained from a plastic wrap extensible, consisting of:

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        open the wrap to set the volume above the load,

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        pleat the side parts of the accordion wrap over pleating fingers, causing casters to intervene motorized that rotate in a first direction of rotation, having each finger an inclination in relation to the direction vertical,

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        stretch then the pleated wrap in the direction horizontal transverse to obtain a larger opening than the perimeter of the load to be packed,

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        and move the stretched envelope above the load according to a vertical direction causing progressive deployment of folds during the sheathing.

State of the art

The use of a film wrap extensible is well known for guaranteeing stability and tightness of a palletized load. Unlike the movie heat shrink, the placement of an extendable cover does not need a source of heat, since it is enough to stretch mechanically previously the matter of the plastic film in the sense horizontal cross section before wrapping the palletized load by pack in. After depositing the wrap stretched over the load, the narrowing of the material of the extensible film is performs naturally by elasticity, which keeps Firmly wrap around the load. The wrap can be made of polyethylene, or any other plastic material extensible.

The wrap is usually stored by rolled up according to a coil, and folded over its section presenting  Four bellows After the winding of the coil, the opening of the wrap is operated by a mechanical action away by the Four angles

Packing machines intended for threading an extendable film cover on the load, they have with this finally a separation device to open the film wrap extensible, and a pleating device to pleat the wrap in accordion on four solidarity fingers with a support box.

According to EP344815, a device for welding is arranged between the separation device and the pleating device to weld the wrap forming a joint welded After welding, the wrap is cut next transversely by a cutting device to make a sheath independent of the coil, and closed at the top. The Pleated sheath is then stretched in a horizontal plane parallel to the weld, and is positioned above the palletized cargo The sheath is deployed during sheathing, and deposited on and around the load after a movement vertical from top to bottom of the frame. Before being stretched by on top of the load, the case suffers in its extended state transverse a longitudinal stretch in the vertical direction of 5% at 15% of its initial vertical length.

The mechanism of the packing machine CO-VERPAL (registered trademark of the Thimon company), It is described in detail in EP1060988. The welding and shear cutting operations to form the cover, are made before deposit on the fingers of pleated, unlike the mechanism described above in the EP344815. The welding is then perfectly cooled when requested by transverse stretching, and resists better elongation constrictions. There are no specific means intended to effect a vertical lengthening of the envelope during the sheathing phase that follows the stretching phase cross.

In figures 1 to 3 representing the phases of pleating and transverse stretching of a packaging machine the prior art, the upper part 12B of each finger 12 is equipped with a stretching shoe 22 that has a curved shape advantageously adapted to film rubbing during Pleated and unfolding stages. The vertical flank of finger 12 it can be equipped with one or two free rollers 13, or be Equipped with a fixed rubbing slip liner weak, so that it imprisons the envelope and drags it towards down during pleating by motorized wheel 14. This The latter is dragged in rotation by a gearmotor 24, and cooperates by tilting with an actuator 20 between a separate position resting (not shown), and a working position (figures 1 to 3) in contact with finger 12.

The four motorized wheels 14 are dragged in rotation in the direction of arrows F1 and F2 to guarantee the pleat of the cover 10 by accumulating it in accordion in the lower part 12A of the fingers 12. The upper part of the cover 10 ha previously closed by a welded joint 16.

The horizontal stretch of the sheath in the direction of arrows F3 and F4 is represented in figure 3. The motorized wheels 14 no longer rotate, and can remain supported in pleating fingers 12 so that they tighten with more or less force the upper horizontal part of the sheath 10 during the stretched across. It is also possible to control the actuators 20 to separate the motorized wheels 14 during this stretch stage in order to allow the film to partially slide over fingers 12 avoiding any possibility tear of the film. Such known mechanisms allow obtain a transverse slip index greater than 10%. The Extensible wrap quality allows to obtain in effect cross stretched from 50% to 100%.

The next phase of sheathing is carried out by a vertical displacement of the frame above the load, of way that causes the progressive unfolding of the cover on the load. After the deposit of the cover, the narrowing of the Extensible film material is naturally effected by elasticity, which guarantees the stable maintenance of the load. The relaxation of matter and the rubbing of the film on the fingers also create a vertical tension of the film on the burden that also contributes to strengthening the stability. This vertical tension is generated without a device particular vertical stretching, since a transverse stretch from 50% to 100% reduces the height of the envelope, and transmits to the load sufficient cohesion forces to ensure stability, since this vertical tension is preserved during cargo deposit.

The angle of inclination A of the fingers 12 with the vertical direction allows to facilitate the accumulation of folds during pleating by motorized casters 14. For a predetermined inclination, the game between the cover 10 and the fingers 12 increases progressively as we approach the bottom, with the consequence of a possibility of disorganization of the folds, which are no longer guided correctly during sliding to the base of the fingers

A weaker angle of inclination A of the fingers 12 would have as main inconvenience to hinder the effect of accumulation of the folds, since the sliding of the film towards the bottom could no longer be made of natural form. Motorized wheels 14, in addition to their function pleated, they must also exercise a second thrust function towards the bottom, which generates rubbing on the upper folds, with risks of formation of points or lines vertical fragility of the envelope before the phase of cross stretched.

In EP633186, the extensible film it is provisionally fitted laterally to the lower part of the load or pallet, against a stop that is located above of the fingers

Object of the invention

The object of the invention is to elaborate a stretching procedure of a packing sheath that allows obtain a free and regular accumulation without disorganization of folds during the pleating phase before transverse stretching, and avoid any risk of tearing the film during Next stage of sheathing.

A development of the invention consists in creating a regular and precise pleated braided cable during the stage of sheathed, and in depositing it on the load at any height, or on the palette.

Another development of the invention relates to a stretching procedure that allows a tension to be obtained controlled film during sheathing.

The stretching process according to the invention it is characterized because the perimeter reduction around is limited of the fingers by a braking and compensation element in the lower part of each inclined finger to distribute adjust the folds before the transverse stretch phase horizontal.

The rubbing of the wrap that descends to along the inclined fingers is done on the two edges of the fingers Any angle or protruding part on these edges I would be in danger of disorganizing the folds.

A disorganization of the folds after the stretching stage is in danger of disturbing the deployment  during the sheathing, creating seizures of the folds between they are likely to cause a tear of the envelope.

The inclination of the fingers facilitates the accumulation of folds, and limiting the perimeter of pleated at the bottom where the game is the most important, prevents disorganization of folds. The presence of the element of braking in the middle of the two edges limits the reduction of perimeter at the bottom of the fingers, without hindering the descent of the wrap along the fingers. All formation of successive seized folds is thus excluded during the transverse stretching, which allows to reliably avoid tears during the next sheathing stage.

According to a development of the invention, a cable Regular pleated braiding can be created in the movie during the sheathing phase, interrupting the downward movement of the cover at a predetermined level, and spinning the casters in a second direction of rotation opposite to the first. For a double finger scrolling, twisted cable film can be accurately deposited at any height level of the palletized cargo We can thus create, either a minifunda to any load level or pallet, either tightness and maintenance of the top of the load, or the tank of the twisted cable over the top of the support vane authorizing a precise release of the input of a clamp automatic palletizer

According to another development of the invention, during the twisted wire formation, we block the lower portion of the sheath part deposited against the stretch shoe, which It is located on the top of the fingers. As a result generates a controlled mechanical tension in the film, with a possibility of vertical stretching of the cover whose value is between 5% and 50% vertical elongation.

The formation of braided cable according to these developments, it is only possible if the organization of folds is perfect.

The invention also relates to a device of packing a palletized cargo by means of a cover constituted by an extensible plastic film, and comprising a control panel equipped with pleated and stretched fingers, each finger consisting of a stretching shoe, a lower part inclined and a motorized wheel driven in rotation by a gearmotor, means to swing each wheel motorized between a separate rest position, and a position of work in contact with the finger, and means of actuation of the box to carry out the sheathing of the load. The bottom inclined of each finger comprises a braking element and of compensation arranged in the lower zone of accumulation of folds where the game between the pleated cover before the phase of stretched transverse, is the most important, being rectilinear said braking and compensation element, and extending vertically forming a protrusion in the central area of the bottom inclined finger.

According to a preferred embodiment, the braking and compensation element has a lower width to the finger, and is in solidarity with its base with the mobile support of the finger The opposite end of the braking element is arranged under a roller on which the motorized wheel is applied during pleating.

According to another feature, an element of fixation is mounted on the support of each finger extending almost at the level of the stretch shoe above the wheel corresponding motorized. The fixing element is associated with an actuator to be moved between a locked position supported against the shoe, and an unlocked position separated from said shoe. The fixing element may be formed by a stop with flexible bead intended to jam a part of the cover against said shoe in locked position.

Brief description of the drawings

Other advantages and features will be deducted from clearer way from the following description of a way of embodiment of the invention provided by way of example no limiting, and represented in the accompanying drawings, in the which:

fig. 1 is a schematic elevation view of a pleating device of an extendable sheath that equips a prior art packing machine;

fig. 2 represents a plan view of the Figure 1;

fig. 3 is a view identical to that of the Figure 1 showing the phase of transverse stretching of the sheath pleated;

fig. 4 is a perspective view of a finger pleated according to the invention;

fig. 5 shows a cross-sectional view of the finger according to line 5-5 of figure 4;

fig. 6 is a view of the finger equipped with a fixing device during the formation of a braided cable pleated;

the figs. 7A-7C illustrate schematically the movement of a finger during deposit of the pleated braided cable over the load;

the figs. 8 to 11 represent the different stages of the sheathing procedure, respectively during the normal route of descent of the frame, during the formation of a pleated braided cable, during transverse separation of fingers, and during the deposition of the twisted cable on the load;

fig. 12 shows a partial view in perspective of the sheath with pleated braided cable tank on the top of the palette, leaving the entrance of the tongs of a palletizer;

fig. 13 is a variant of Figure 10, without special fixing device.

Description of a preferred embodiment

Referring to figures 4 and 5, the part inclined lower 12A of each finger 12 is provided with an element of rectilinear braking 26, which extends vertically forming a projection of the central zone, and has a width L1 less than the L2 of the finger 12. The base of the braking element 26 is in solidarity with the mobile support 28 of finger 12, and its end opposite is located below the lower roller 13 without touching it. The value of angle A can be between 0 and 25 °.

The braking element 26 constitutes a means of compensation arranged in the lower accumulation zone where the play between the sheath 10 pleated and the bottom 12A inclined Finger 12 is the most important. The presence of the elements of braking 26 on the four fingers 12 inclined limits the reduction perimeter around fingers 12, while allowing a unobstructed accumulation of the folds at the bottom 12A, and a uniform and regular distribution of the folds along the neighboring vertical edges A1 and A2. The transverse stretch of the cover 10 can then be made as in figure 3 (arrows F3 and F4), by separation in a horizontal plane from the supports 28 through the four corners of the frame, and avoiding all formation of irregular or seized folds that are at risk of tears during the sheathing phase.

In Figure 6, a fixing element 30 is mounted on the support 28 of each finger 12, extending almost to the shoe level 22 above motorized wheel 14. He fixing element 30 is coupled to an actuator 32 so which is shifted between a locked position and a position of unlock The fixing element 30 is formed by way of example by a stop with flexible rubber tip, which is supported by lock position against shoe 22 to imprison the part bottom of the cover 10 by the four corners.

The actuator 32 may be constituted by a pneumatic, hydraulic or electric control cylinder. The gearmotors 24 of the four rotating casters 14 are piloted by variable speed drives depending on various parameters, and whose direction of rotation can be reversed during the pleated and sheathed phases.

In this way it is possible to make a cable twisted 34 pleated terminal at the end of sheath 10 during or at the end of the sheathing phase. Just interrupt the downward movement of the stretching frame in one place predetermined, and with tilting the wheels 14 in mode of pleated resting on rollers 13, but reversing the direction of rotation (arrow F5, figure 6) in relation to the (arrow F2, figure 1) used for pleating before transverse stretching. The folds of braided cable 34 accumulate between the roller upper 13 and the stretching shoe 22 during the rotation of the wheel 14 according to direction F5.

According to Figures 7A-7C, the twisted cable film of sheath 10 can then be deposited on palletized CH cargo after double displacement of the four fingers 12 according to arrows F6 and F7. TO from figure 7A corresponding to the cable formation braided 34 according to figure 6, we separated fingers 12 according to a first translation movement indicated by arrow F6 (figure 7B), followed by a second orthogonal release movement vertical (arrow F7, figure 7C) for cable application braided 34 on load CH.

In this way it is possible to obtain a deposit Precise braided cable 34 at any height level of the palletized cargo Simply interrupt the descent path of the frame at a predetermined height, and with activating the phase of pleated for the formation of braided cable 34 by means of the casters 14 that rotate according to the direction of arrow F5. This procedure allows to create a minifunda well at any level of the load or the pallet, well the tightness and maintenance of the top of the CH load, or the cable tank braided 34 on top of the palette authorizing a precise release of the input of a palletizer clamp automatic, as shown in figure 12.

The presence of fasteners 30 allows also make the previous function reliable, thanks to the binding of the cover 10 in the locked position of the actuators 32. A mechanical tension effect is thus generated in the vertical part upper of the caster deposited keeping the movie.

The different stages of implementation of procedure are illustrated in the figures 8-11:

Figure 8 shows the stage of sheathed with the CH load, which follows the stretching phase cross section of figure 3. During the descent path of the finger support frame 12, the fixing element 30 is found in a separate position, as well as the wheel 14 of pleated. The film of the cover 10 slides freely to the length of the curved shoe 22, and the unfolding of the folds is performs progressively and without hindrance during the tour of descent indicated by arrow F8.

In figure 9, the movement of lowering of the frame for the formation of a braided cable. He fixing element 30 of each finger 12 is actuated in the position of lock jamming the film against shoe 22 in the four angles After tilting the wheel 14 motorized against the rollers 13, we form the braided cable after the rotation of the caster in the direction of arrow F5.

In Fig. 10, the support 28 of the fingers 12 is then separated horizontally in the direction of the arrow F9. The fixing element 30 and the motorized wheel 14 of each finger 12 remain in contact with the sheath during that separation movement, so that they maintain a positioning correct twisted cable between shoe 22 and roller upper 13, and retain the tension of the film in the part of The case already deposited.

In Figure 11, the horizontally approach fingers 12 for the deposit of the twisted cable 34 in a precise place of load CH or pallet 36, followed by a movement of release of the support 28 from the fingers 12 towards the bottom according to arrow F7. The fixing element 30 is actuated then towards the unlocked position to release the cable braided 34 during your deposit. The vertical part of the cover 10 remains tensioned during the formation of the braided cable 34 pleated, and can even be stretched according to a value that can reach 5% to 50% vertical elongation.

Indeed, during the handling of loads, the vertical tension of the wrapping piece that joins the first layer of products with palette 36 is essential to ensure a Good posture of the load. At the end of the sheathing stage, the vertical stretching associated with the braided cable deposited against the pallet, guarantees the stability of the load.

In figure 12, we appreciate that the cable braided is located just above the pallet release  36 to authorize the entry of the clamp of a palletizer.

Referring to figure 13, the element of fixing 30 is suppressed, and the end of the stretch shoe 22 forms a projection sufficient to retain the braided cable at the top of the finger This braided cable is a continued deposited in the load according to the same cycle previously described.

The invention also applies to a flat wrap, open for depression, and taken by four points for the holster box.

Claims (14)

1. Placement procedure on a load (CM) palletized from a flexible packaging wrapper obtained from from an extensible film wrap, consisting of:

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open the wrap to set the volume above the load,

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pleat the side parts of the accordion wrap on fingers (12) pleated, causing casters to intervene (14) motorized rotating in a first direction of rotation (F1, F2), each finger having an inclination in relation to the direction vertical,

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stretch then wrap pleated in the horizontal transverse direction to obtain a opening larger than the perimeter of the load (CM) by pack in,

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Y move the stretched envelope above the load (CM) according to a vertical direction causing progressive deployment during the sheathing.

characterized in that the perimeter reduction around the fingers (12) is limited by a braking and compensation element (26) in the lower part (12A) of each inclined finger to distribute the folds regularly before the transverse stretching phase horizontal. 2. Method according to claim 1, characterized in that during the sheathing phase, we interrupt the movement of lowering the sheath (10) to a predetermined level, and a twisted cable (34) is formed by rotating the casters (14) in a second direction of rotation (F5) opposite the first. Method according to claim 2, characterized in that the deposited portion of the sheath (10) is locked against the stretching shoe (22) in the upper part (12B) of the fingers during the formation of the twisted cable (34). Method according to claim 2 or 3, characterized in that the braided cable (34) is retained against a protruding part of the shoe (22) in the upper part of the finger. 5. Method according to one of claims 1 or 2, characterized in that during or at the end of the sheathing phase, we block the sheath (10) against the fingers (12) to obtain a controlled vertical mechanical tension in the film. Method according to claim 4 or 5, characterized in that the film of the sheath (10) is stretched according to a value between 5% and 50% vertical elongation. 7. Packing device for a load palletized (CH) by means of a cover (10) constituted by a extensible plastic film, and comprising:

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a control panel equipped with pleated and stretched fingers (12), each finger consisting of a stretching shoe (22) and a part sloping bottom,

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a motorized wheel (14) driven in rotation by a gearmotor (24) to cooperate with each finger (12),

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some means for tilting each motorized wheel (14) between a separate resting position and a working position in contact with the finger (12),

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some means for actuating the panel to carry out the sheathing of the load (CM),

characterized in that the inclined lower part (12A) of each finger (12) comprises a braking and compensation element (26) disposed in the lower zone of accumulation of the folds where the play between the pleated sheath before the transverse stretching phase , is the most important thing, said braking and compensation element (26) being rectilinear, and extending vertically forming a projection of the central area of the inclined lower part (12A) of the finger (12). 8. Packaging device according to claim 7, characterized in that the braking element (26) has a width (L1) smaller than that of the finger (12), and is connected at its base with the mobile support (28) of the finger ( 12). 9. Packaging device according to claim 7, characterized in that the opposite end to the braking element (26) is arranged under a roller (13) on which the motorized wheel (14) is applied during the pleating. Device according to claim 8 or 9, characterized in that a fixing element (30) is mounted on the support (28) of each finger (12) extending almost to the level of the shoe (22) stretched above the wheel (14) corresponding motorized. Device according to claim 9 or 10, characterized in that the fixing element (30) is associated with an actuator (32) to be moved between a locking position supported against the shoe (22), and a separate unlocking position of said shoe. 12. Device according to claim 10, characterized in that the fixing element (30) is formed by a stop with flexible bead intended to block a part of the cover (10) against said shoe (22) in the locked position. 13. Device according to claim 11, characterized in that the actuator (32) is constituted by a pneumatic, hydraulic or electric control cylinder. 14. Device according to one of claims 7 to 12, characterized in that the gearmotor (24) of each wheel (14) is driven by a speed variator in reverse of the direction of rotation.