EP4620846A1

EP4620846A1 - Wrapping machine and related method

Info

Publication number: EP4620846A1
Application number: EP25165003.2A
Authority: EP
Inventors: Antonio Grassi
Original assignee: Ercopac Srl
Current assignee: Ercopac Srl
Priority date: 2024-03-22
Filing date: 2025-03-20
Publication date: 2025-09-24

Abstract

Wrapping machine (100) for wrapping a palletised load (500) comprising, a wrapping apparatus (30) configured to support and unwind a reel (520) of protective packaging material (510) in particular an extensible film to be wrapped around a side surface (504) of the palletised load (500), a positioning device (20) of a cover sheet (530), said cover sheet (530) being adapted to cover an upper surface (505) of the palletised load (500) and comprising side portions ( 531) which protrude from said upper surface (505) and which fold downwards near the side surface (504) in particular along fold lines (531a) at edges (505a) of said upper surface (505), characterised in that the wrapping machine (100) further comprises a pressor device (40) for retaining the cover sheet (530) on the upper surface (505) of the palletised load (500), preferably exerting a vertical direction force and comprises lifting means (200) for lifting the side portions (531) of the cover sheet (530) moving them away from the side surface (504) of the palletised load (500).

Description

FIELD OF APPLICATION OF THE INVENTION

This invention fits into the field of wrapping machines for wrapping palletised loads, in particular by means of extensible film.
In particular, said wrapping machines comprise, in combination or integrated therein, a sheet-laying apparatus for laying a cover sheet on the palletised load, in a position above the load.

STATE OF THE ART

Automatic wrapping machines for the packaging and the stabilization of palletized loads, i.e. articles stacked on loading pallets, are known in the state of the art.
This allows preserving the integrity of the load and facilitates the transport and storage of the articles.
The known wrapping machines can be of various types, for example with rotating arm and fixed palletised load or with fixed arm and rotating palletised load, or of another type.
The wrapping machines generally use extensible-type film to protect all or part of the vertical surface of the load.
When a more complete protection is required, these wrapping machines are combined with apparatuses that apply cover sheets on the top of the palletized loads to be wrapped, so as to preserve them from external agents such as water or dust that could otherwise deposit and/or penetrate inside.
Furthermore, depending on the type of wrapping of the palletized load, such as of the anti-dust or waterproof type, the film is wrapped around the load in different ways, and also the cover sheet can consequently be applied at different moments.
Said apparatuses that apply cover sheets can be integrated into the wrapping machine, or be autonomous and generally inserted before the load wrapping station.
In fact, immediately after the application of the cover sheet, the load reaches the wrapping position inside the wrapping machine and a pressor device is positioned on the top of the same load, keeping the cover sheet in the correct position during the wrapping.
Subsequently, a wrapping head, which supports a film reel suitable for wrapping the load sideways, is placed next to the load itself; the relative rotation between the wrapping head and the load causes the film, suitably pre-stretched, to be wrapped around the load as desired.
In well-known machines, especially when wrapping occurs by rotating the pallet and keeping the reel fixed, a pressor device is often present, i.e. an element with a flat surface adapted to rest on the upper surface of the pallet and to exert a pressure that prevents the pallet from tilting and the product from falling while being wrapped. Said pressor device is rotatable around a vertical rotation axis and rotates integrally with the pallet; it is generally driven into rotation by contact with the rotating pallet itself.
The presence of the pressor device is important to ensure the reliability of the wrapping.
When the sheet-laying apparatus is autonomous with respect to the wrapping machine, a reduction in working times is possible as it allows to disguise the time required for inserting the cover sheet in the time for wrapping the palletized load preceding it.
In machines of the known type, the upper cover sheet-laying apparatus may comprise a portal structure or an anthropomorphic robot, capable of being placed over the palletized load, along the advancement line of said load through the machine.
In fact, a known anti-dust type wrapping mode involves firstly, the application of the cover film on the top of the palletised load, and then the wrapping of the film on the side surface of the entire load, in particular starting from the top and then descending towards the base.
On the contrary, an anti-water wrapping mode, involves wrapping the film from the base of the load to then rise up to the top, and subsequently the cover film can be applied.
The film that laterally surrounds the load must be applied in such a way as to block the upper cover sheet firmly in place to prevent the penetration of external agents.
A required cycle that guarantees excellent load insulation involves wrapping the film on the side surface of the entire load up to the top, then involves inserting the cover film on the top and then performing a subsequent wrapping of the film on the side surface to retain the side edge of the cover film.
Known machines involve performing this cycle by wrapping the film on the side surface of the entire palletised load and simultaneously keeping the pressor device in the operating position.
Next, they involve moving the pressor device away from the load in order to apply the cover film to the top of the load. They involve repeating the wrapping of the side surface while retaining the side edge of the cover film. This second wrapping can take place with the pressor device in a non-operating position, i.e. remaining detached from the pallet.
Removing the pressor device may affect the stability of the load and the positioning of the top cover film.
Alternatively, before the second wrapping, the pressor device can be repositioned to rest on the upper surface of the pallet and exert the pressure necessary to ensure the stability of the pallet during its rotation.
This repositioning of the pressor device slows down the load wrapping cycle, reducing the machine production capacity.
It should be considered that the production capacity of the machine running this cycle is already slowed down by the fact that it involves interrupting the wrapping process to insert the cover film.

EXPOSURE AND ADVANTAGES OF THE INVENTION

The technical problem underlying the present invention is to make available to the art a wrapping machine and related method for wrapping the palletised load that is structurally and functionally designed to overcome one or more of the limitations set forth above with reference to the aforementioned prior art.
In the context of the aforementioned problem, a main object of the invention is to make available a wrapping machine and related method which involves performing a wrapping cycle that ensures excellent load insulation, with a reliable operating cycle that does not involve any risk of the load falling.
A further object of the invention is also to make available to the art a wrapping machine and related method which involves performing a wrapping cycle, with cover film management, at a high production rate.
These and other objects are achieved by the characteristics of the invention as set forth in the independent claims. The dependent claims outline preferred and/or particularly advantageous aspects of the invention.
In particular, the present invention makes available a wrapping machine for wrapping a palletised load comprising, a wrapping apparatus configured to support and unwind a reel of protective wrapping material in particular an extensible film to be wrapped around a side surface of the palletised load
Preferably, the wrapping machine further comprises a cover sheet positioning device.
In particular, said cover sheet is adapted to cover an upper surface of the palletised load and comprises side portions which, once positioned on the upper surface, protrude from said upper surface and fold downwards near the side surface, in particular along fold lines at the edges of said upper surface.
Preferably the wrapping machine further comprises a pressor device to retain the cover sheet on the upper surface of the palletised load.
Preferably, the pressor device exerts a force on the upper surface of the palletised load in the vertical direction.
Preferably, the wrapping machine is configured to perform the wrapping by rotating said palletised load around its axis of symmetry.
Preferably the wrapping machine further comprises lifting means to lift the side portions of the cover sheet moving them away from the side surface of the palletised load.
Preferably, said lifting means are positioned at one or more sides of the palletised load.
Advantageously, said lifting means are positioned at each of the side portions of the cover sheet.
Advantageously, the lifting means make each of the side portions of the cover sheet rotate around the fold lines.
Preferably, the lifting means bring said side portions into a substantially horizontal position.
Preferably, the lifting means comprise blowing elements, preferably powered by compressed air, adapted to emit an air blow.
Preferably, the blowing elements are positioned below the side portions of the cover sheet.
Optionally, the blowing elements are positioned near a base of the palletised load so as to emit an upward air blow.
Preferably, the blowing elements are positioned below movement means.
Preferably, the pressor device comprises a support body adapted to rest on the upper surface.
Advantageously, the support body is planar.
Optionally, the support body comprises abutment means that extend so as to protrude from the upper surface of the palletised load when the pressor device is in operating position.
Optionally, the support body has a dimension greater than the upper surface, so that when the pressor device is in the operating position, a perimeter portion thereof protruding from the upper surface defines abutment means.
Preferably the support body has dimensions smaller than or equal to the upper surface.
Preferably, the abutment means are movable between a retracted position and an extended position.
Preferably the support body comprises retaining means to retain the side portions of the cover sheet in a substantially horizontal position.
Advantageously the retaining means are positioned at and below the abutment means to retain the side portions interposed between them.
Advantageously, the retaining means are movable between an operating position in which they retain the side portions of the cover sheet in a substantially horizontal position and a non-operating position in which they release them.
Optionally, the wrapping machine comprises lowering means for folding the side portions downwards near the side surface, in particular along fold lines at edges.
Preferably the lowering means are installed on the support body.
Advantageously the lowering means comprise second blowing elements, preferably powered by compressed air, adapted to emit an air blow.
In particular, the present invention also makes available a method which involves wrapping a palletised load by means of a protective wrapping material, in particular an extensible film for wrapping a side surface, and by means of a cover sheet for covering an upper surface of the palletised load comprising side portions which protrude from said upper surface and which fold downwards near the side surface, in particular along fold lines at edges of said upper surface.
Preferably while performing said wrapping, the method involves pressing the upper surface of the palletised load with a support body.
Preferably, said method involves performing a wrapping that comprises a first wrapping cycle to wrap part or all of the side surface, up to near the upper surface without encompassing the side portions of the cover sheet, and a second wrapping cycle that involves wrapping the side surface so that the protective wrapping material covers the side portions of the cover sheet.
Preferably, said method involves not detaching the support body from the upper surface of the palletised load while performing the entire wrapping process.
Preferably said method involves performing the wrapping of the palletised load, according to the steps of positioning the cover sheet on the upper surface of the palletised load.
Preferably, said method involves positioning the pressor device with a support body at the upper surface to retain the cover sheet and press it onto the palletised load.
Preferably said method involves lifting the side portions of the cover sheet and retaining them in a substantially horizontal position.
Preferably, said method involves performing a first wrapping cycle, which involves wrapping part or all of the side surface, in particular so that the protective wrapping material covers the upper side area of the palletised load, right up to the upper surface.
Preferably, said method involves, without moving the support body, releasing said side portions of the cover sheet so that they fold downwards near the side surface.
Preferably, said method involves performing a second wrapping cycle that involves wrapping the side surface so that the protective wrapping material covers the side portions of the cover sheet.
Preferably said method involves lifting the support body from the upper surface and evacuating the palletised load.
Preferably, said method involves lifting the side portions of the cover sheet by blowing air from below towards said side portions.
Preferably, said method involves releasing and folding the side portions downwards near the side surface, particularly along fold lines at edges by blowing air from above towards said side portions.
Preferably, said method involves performing the first and/or second wrapping cycle by rotating the palletised load.
Said objects and advantages are all achieved by the improved wrapping machine and associated method, subject matter of the present invention, which is characterized by what is provided for in the following claims.

BRIEF DESCRIPTION OF THE DRAWINGS

This and other features will become more apparent from the following description of some preferred embodiments illustrated, by way of non-limiting example in the accompanying drawings.

Figure 1a: shows an axonometric view of a palletised load wrapping machine with a cover sheet positioning device;
Figure 1b: shows a plan view of the machine with cover sheet lifting means;
Figure 1c: shows a plan view of the pressor device;
Figure 2: shows a side view of the wrapping machine with the palletised load in the cover sheet insertion position;
Figure 3: shows a side view of the machine in a step of starting the first wrapping;
Figure 4: shows a side view of the machine in a step of ending the first wrapping;
Figure 5: shows a side view of the machine in a step between the first and second wrapping;
Figure 6: shows a side view of the machine in a step of starting the second wrapping;
Figure 7: shows a side view of the machine in a step of ending the second wrapping.

DESCRIPTION OF THE INVENTION

With particular reference to the figure, a machine 100 for wrapping a palletised load 500 is represented.
The palletized load 500 also referred to as pallet, generally comprises a support pallet 501 on which a plurality of products are stacked.
The dimensions of said palletised load 500 may vary between various sizes such as 900x600, 800x600, 800x1200, 100x1200, 1420x1120, etc., which are generally the standard dimensions of a support pallet 501.
In particular, said palletised load 500 is wrapped by means of protective packaging material 510.
Said packaging material can be of different types, preferably an extensible film. The extensible film 510 is for example made of polyethylene.
Alternatively, protective packaging materials 510 such as mesh-formed materials, paper-type materials, etc., may also be used.
In the following, the protective packaging material 510 will also be simply called film 510 without thereby restricting the field of application of the invention.
A side surface 504 of the palletised load 500 is wrapped by means of said protective packaging material 510.
Said machine 100 comprises a wrapping apparatus 30 configured to support and unwind a reel 520 of protective wrapping material 510 to be wrapped around the palletised load 500.
Said machine 100 preferably comprises movement means 10 adapted to support and/or move the palletised load 500 into the wrapping operating position.
Said wrapping apparatus 30 is configured to cooperate with said movement means 10.
As represented in the figure, said support means may provide drive means for advancing the pallet 500 as far as to the wrapping position. Alternatively, they can simply be rests for the pallet 500 that can be positioned in the wrapping position by means of external means such as a forklift or a pallet truck or agv.
As is known to a person skilled in the art, said movement means 10 can be, for example, of the roller conveyor or catenary type. The type of the movement means 10 generally depends on the conformation of the type of pallet 501, as well as on the type of stacked products and on their stability.
In the figures and in the description, we will often refer to roller conveyor-type movement means 10. It is understood, however, that the same considerations can be developed in relation to movement means 10 of a different type, such as with catenary.
Known wrapping machines 100 can be of various types, such as with rotating wrapping apparatus 30 and fixed palletised load 500 or with fixed wrapping apparatus 30 and rotating palletised load 500.
In case the machine 100 works with a rotating palletised load 500, a preferred embodiment provides that said movement means 10 are configured to rotate the palletised load 500.
Preferably, said rotation takes place according to a vertical axis X that substantially coincides with the axis of symmetry of the pallet 500 itself except for the positioning and conformation tolerances of said palletised load 500. Said wrapping apparatus 30 is further configured to cooperate with said movement means 10.
In case of a machine with a rotating palletised load, in fact, during the rotation of the movement means 10 and the relative pallet 500 in position on them, the wrapping apparatus 30 allows the unwinding of the reel 520 to transfer the film 510 around the side surface 504 of the load 500.
Generally, the machine 100 comprises blocking means that retain a first flap 511 of said film 510 unwound from the reel 520 so that said first flap 511 moves integral with the pallet 500 during the work cycle of the machine 100.
Said blocking means can be positioned at the base of the pallet 500, e.g. integrated into the movement means 10.
Alternatively, they can be positioned at the top of the pallet 500, e.g. integrated into a pressor device 40, which stabilises the palletised load 500 during wrapping.
Other solutions known to a person skilled in the art involving different configurations of the blocking means are to be considered within the scope of protection of the invention.
According to a preferred embodiment, said machine 100 comprises a lifting body 31 adapted to support and move a wrapping head 35, as depicted in the figures on which the reel 520 is installed.
In particular, said wrapping head 35 is vertically movable along the lifting body 31.
Preferably the wrapping head 35 is vertically movable during the rotation of the palletised load 500 in order to wrap the palletised load 500 over a part or all of its height.
Said machine 100 preferably comprises a positioning device 20 of the cover sheet 530.
Said positioning device 20 is configured to position the cover sheet 530 so as to cover an upper surface 505 of the palletised load 500.
A preferred embodiment provides that the cover sheet 530 comprises side portions 531 that protrude from said upper surface 505 when positioned.
In particular, when the cover sheet 530 is placed on the upper surface 505, said side portions 531 protrude from each side of the pallet.
In particular, when the cover sheet 530 is positioned on the upper surface 505, said side portions 531 are adapted to fold downwards near the side surface 504, in particular along fold lines 531a at edges 505a of said upper surface 505.
Preferably said side portions 531 have a height of about 30 cm. Said positioning device 20 may be downstream of the wrapping apparatus 30.
It is therefore positioned at the movement means 10, in a station preceding the one where the wrapping of the protective packaging material 510 takes place, around the palletised load 500.
In this case, the sheet positioning device 20 can be managed together with the wrapping apparatus 30, or be a completely independent positioning device 20 of the sheet 530.
For example, the positioning device 20 of the sheet 530 can be centralised and serve one or more wrapping devices 30.
Alternatively, the sheet positioning device 20 can be integrated into the wrapping apparatus 30 itself.
It can therefore be positioned at the movement means 10, in the same station where wrapping of the protective packaging material 510 takes place, around the palletised load 500.
According to one aspect of the invention, the device 20 can be configured in different ways. In fact, it can provide a portal structure, a column structure, or alternatively an anthropomorphic robot structure.
Said positioning device 20 of the sheet 530 must be able to place itself over the palletized load 500 on which the cover sheet 530 is to be placed.
Said positioning device 20 of the sheet 530 may further comprise a feed device 53 configured to rotatably support a film reel 530b.
A plurality of said sheets 530 can be obtained from said reel 530b, by unwinding and cutting the film of the reel 530.
The cover sheet 530 thus made can be picked up by the positioning device 20 to deposit it on the palletized load 500.
In particular, the positioning device 20 lifts the sheet 530 and brings an edge thereof above the load 500.
At this point, the relative translation between the positioning device 20 and the load 500 causes the sheet 530 to be placed on top of the load 500 to cover the upper surface 505.
We will not go into the details of the positioning device 20 of the sheet 530 as it can be made in various ways known to a person skilled in the art.
However, it is understood that alternative solutions known to a person skilled in the art and any variations in detail that may be necessary for technical and/or functional reasons, are considered as of now to fall within the same protective scope.
One embodiment, depicted in the figure, provides that the machine 100 comprises a pressor device 40.
Said pressor device 40 comprises a lifting structure 42 on which a support body 45 is installed to move it in a vertical direction.
In particular, the support body 45 is adapted to rest on the upper surface 505.
Said support body 45 is preferably planar.
Said pressor device 40 is generally positioned above the pallet 500 that is to be wrapped.
Said pressor device 40 is configured to retain the cover sheet 530 on the upper surface 505 of the palletised load 500.
Preferably, said pressor device 40 retains the cover sheet 530 by exerting a force/pressure in a vertical direction on the pallet 500.
Said support body 45 may comprise a deformable lower surface 41 to better adapt to the conformation of the upper surface 505 on which it exerts force/pressure.
According to a preferred aspect of the invention, the support body 45 is adapted to remain in contact with the upper surface 505 of the load 500 during the entire wrapping cycle. This ensures maximum winding reliability by reducing the risk of product falls or pallet 500 instability.
Preferably in the machine 100 working with a rotating palletised load 500, the support body 45 is configured to be rotatable in particular around the axis of symmetry of the palletised load 500 on which it rests.
During the rotation of the load 500, the support body 45 follows said rotation by being pulled by friction and contact pressure with the upper surface 505.
Said pressor device 40 may comprise means to rotate the support body 45 with the correct orientation on the upper surface 505 before resting on it.
A required wrapping cycle that guarantees optimum load insulation, from external contamination, involves performing at least on the upper portion 500' of the pallet 500 a double wrapping involving:

a first wrapping in which the film 510 wraps the side surface 504 up to the upper surface 505 of the pallet 500 without affecting the cover sheet 530.
a second wrapping in which the film 510 wraps the side surface 504 up to the upper surface 505 of the pallet 500, encompassing the side portions 531 of the cover sheet 530 that are folded downwards near the side surface 504.

In known machines, this cycle is performed by placing the cover sheet 530 only after performing the first wrapping.
In fact, the first wrapping must not encompass the side portions 531 of the cover sheet 530.
If at the time of the first wrapping the cover sheet 530 was already in place, its side portions 531 would be folded by gravity downwards near the side surface 504, in particular along fold lines 531a at the edges 505a of said upper surface 505 and would therefore be encompassed in the first wrapping.
In order to insert the cover sheet 530 after the first wrapping, it is necessary to detach the support body 45 from the upper surface 505 of the pallet 500, position the cover sheet 530 and reposition the support body 45 in the operating position resting on the pallet 500.
Only after said steps can the second wrapping be performed.
Therefore, in addition to reducing the reliability of the machine due to the detachment of the support body 45 of the pressor device 40, a slow wrapping cycle is obtained.
In fact, the cover sheet 530 cannot be inserted either downstream of the wrapping apparatus 30 or before starting the first wrapping, but only between the first and second wrapping, thus interrupting the wrapping cycle. In fact, if this were the case, the side portions 531 of the cover sheet 530 would also be encompassed with the first wrapping.
In order to improve the performance of said cycle, a preferred embodiment provides that said machine 100 comprises lifting means 200, to lift the side portions 531 of the cover sheet 530 moving them away from the side surface 504 of the palletised load 500.
Thanks to this solution, it is possible to perform the first wrapping by wrapping the side surface 504 up to the upper surface 505 of the pallet 500 without affecting or encompassing the cover sheet 530.
This allows to perform the cycle described above with a high degree of reliability, as there is no need to detach the support body 45 of the pressor device 40.
It also guarantees faster cycle times as the cover sheet 530 can be inserted downstream of the wrapping apparatus 30 or before starting the first wrapping without causing an interruption between the first and second wrapping.
According to a preferred aspect of the invention, the lifting means 200 are positioned at one or more sides of the palletised load 500.
In particular, the lifting means 200 are located at each of the side portions 531 of the cover sheet 530.
Therefore, one possible solution provides that the lifting means 200 are arranged on each side of the pallet 500 so that each one operates on the respective side portion 531 of the cover sheet 530.
Advantageously, said lifting means 200 rotate each of the side portions 531 of the cover sheet 530 around the respective fold line 531a.
Preferably said rotation is performed to bring said side portions 531 into a substantially horizontal position.
It is therefore a rotation of approximately 90° preferably greater than or equal to 90°.
A rotation of more than 90° allows the side portions 531 not to interfere with the feed device 53 or with the film reel 530b. Due to the substantially horizontal position reached by the side portions 531 of the cover sheet 530, it is possible to reach, with the first wrapping, the height of the upper surface 505 of the pallet 500 without affecting or encompassing the cover sheet 530.
One possible embodiment provides that the lifting means 200 comprise blowing elements 201, adapted to emit an air blow.
Said lifting devices 200 are preferably powered by compressed air.
This solution allows to lift the side portions 531 of the cover sheet 530 without making contact to avoid problems related to grip uncertainty.
In addition, this solution is simple and cost-effective, as it does not require mechanical means and relative actuation.
However, alternative solutions that operate by contact are also possible, such as suction cups or grippers that engage on said side portions 531, in which case the solution is more complex, but ensures the precision of the lifting position of the side portions 531.
According to one embodiment, the blowing elements 201 are positioned below the side portions 531 of the cover sheet 530, i.e. in a position which is lower, in a vertical direction, than the area where said side portions 531 overlap with the side surface 504.
In the figure, a preferred embodiment provides that the blowing elements 201, are positioned near a base 502 of the palletised load 500.
Preferably, the air blow is emitted from the bottom upwards.
Preferably, the blowing elements 201 are positioned underneath the movement means 10.
This ensures that they do not hinder the exit of the pallet 500 or wrapping operations.
In the figure, the blowing elements 201 are arranged below the movement means 10 and in such a way that they are on each side of the pallet 500 when it is in the wrapping position.
If the movement means 10 are, for example, roller conveyors, the blowing elements 201 can be positioned in the space between the rolls.
According to one aspect of the invention, in order to prevent the rotation of the side portions 531 from going too far beyond the substantially horizontal position and to prevent their position from being incorrectly controlled, the support body 45 may comprise abutment means 41.
Said abutment means 41 preferably extend so as to protrude from the upper surface 505 of the palletised load 500 when the support body 45 is in the operating position.
In particular, one possible embodiment provides that the support body 45 has a dimension greater than the upper surface 505.
In such a case, the support body 45 comprises a perimeter portion that protrudes from the upper surface 505 and defines the abutment means 41.
For example, the support body 45 may be a rectangular plane with an area greater than the upper surface 505.
When the pressor device 40 is in the operating position, with the support body 45 resting on the upper surface 505, the protruding perimeter portion defines a support surface for the side portion 531 which is lifted by the blowing elements 201.
This prevents the side portion 531 from rotating beyond 90°, for example by positioning itself so that it cannot fall along the side surface 504 at the end of the action of the blowing elements 201.
Said embodiment of the abutment elements 41 is a simple and cost-effective solution.
According to an alternative embodiment, depicted in the figure, the support body 45 has a dimension lower than or equal to the upper surface 505.
In this case, the abutment means 41 may be movable between a retracted position and an extended position.
In particular, when the abutment means 41 are in the extended position, they define a support for the side portion 531 that is lifted by the blowing elements 201.
At the end of the lifting of the side portion 531, the abutment means 41 can be returned to the retracted position.
This allows to reduce the bulkiness of the support body 45.
An advantageous variant may provide for the support body 45 to be divided into two parts 45a 45b, of which an outer perimeter part 45a surrounding an inner part 45b.
Preferably said inner part has a dimension lower than the upper surface 505.
Preferably the outer perimeter part 45a can be lifted in relation to the inner part 45b.
Said outer perimeter part 45a may comprise the perimeter portion, which protrudes from the upper surface 505.
In particular, after the side portions 531 have been lowered near the side surface 504 to perform the second wrapping wherein the film 510 wraps the side surface 504 up to the upper surface 505 of the pallet 500 encompassing said side portions 531 of the cover sheet 530, the outer perimeter portion 45a is lifted with respect to the inner perimeter portion 45b which remains resting on the upper surface 505 of the pallet 500.
This makes it possible to continue wrapping the load 500 at the cover sheet 530, even protruding onto the upper surface 505 of the pallet 500 to obtain a greater wrapping further stabilising the cover sheet 530.
In addition, wrapping is obtained ensuring maximum reliability as the pallet 500 is always retained by the inner part 45b of the support body 45 resting on the upper surface 505 of the pallet 500.
According to an advantageous embodiment, the support body 45 of the pressor device 40 may comprise retaining means, not shown in the figure, to keep the position of the side portions 531 under control when they are lifted.
Such retaining means are adapted to hold the side portions 531 of the cover sheet 530 in a substantially horizontal position.
According to one embodiment, the retaining means are positioned at and below the abutment means 41.
In this way, the side portions 531 are interposed between the retaining means and the abutment means 41.
This can also allow to interrupt blowing once the retaining means have operated, thus saving energy.
Alternatively, in the absence of the retaining means, the side portions 531 are retained in a lifted position while continuing to emit air from the blowing elements 201.
Preferably, such retaining means are movable between an operating position in which they retain the side portions 531 in a substantially horizontal position and a non-operating position in which they release them.
Advantageously, the machine 100 comprises lowering means 202 for folding the side portions 531 downwards near the side surface 504, in particular along fold lines 531a at the edges 505a.
Preferably such lowering means 202 are installed on the support body 45.
The lowering means 202 ensure that the side portions 531 return to the initial position they had before being lifted.
In this way, the side portions 531 descend to their initial position along the side surface 504, not only by the force of gravity.
An advantageous embodiment provides that the lowering means 202, comprise second blowing elements 203, preferably powered by compressed air, adapted to emitting an air blow.
Thus, the machine 100 described allows to apply the operating method also covered by the present invention.
In particular, said method involves performing the wrapping of a palletised load 500 by means of a protective packaging material 510 in particular an extensible film to wrap a side surface 504 and by means of a cover sheet 530 to cover an upper surface 505 of the palletised load 500.
In particular, the cover sheet 530 comprises side portions 531 protruding from said upper surface 505 and folding downwards near the side surface 504, in particular along fold lines 531a at edges 505a of said upper surface 505.
Said method involves performing the wrapping of the palletised load 500, preferably according to the following steps:

positioning the cover sheet 530 on the upper surface 505 of the palletised load 500,
positioning the pressor device 40 with the support body 45 at the upper surface 505 to retain the cover sheet 530 and pressing onto the palletised load 500,
lifting the side portions 531 of the cover sheet 530 and retaining them in a substantially horizontal position,
performing a first wrapping cycle that involves wrapping part or all of the side surface 504, in particular so that the protective packaging material 510 covers the upper area of the palletised load 500, up to near the upper surface 505,
without moving the support body 45, releasing said side portions 531 of the cover sheet 530, so that they fold downwards near the side surface 504,
performing a second wrapping cycle, which involves wrapping the side surface 504 so that the protective packaging material 510 covers the side portions 531 of the cover sheet 530,
lifting the support body 45 from the upper surface 505 and evacuating the palletised load 500.

Before lifting the support body 45 from the upper surface 505 and evacuating the palletised load 500, an advantageous variant may provide that the outer perimeter portion 45a of the support body 45 is lifted relative to the inner portion 45b which remains resting on the upper surface 505 of the pallet 500, in order to continue wrapping the load 500 at the cover sheet 530, even protruding onto the upper surface 505 of the pallet 500. An advantageous embodiment of said method involves lifting the side portions 531 of the cover sheet 530 by blowing air from below towards said side portions 531.
Furthermore said method may involve releasing and folding the side portions 531 downwards near the side surface 504, in particular along fold lines 531a at edges 505a by blowing air from above towards said side portions 531.
A preferred embodiment shown in the figure provides that the first and/or second wrapping cycle takes place by rotating the palletised load 500.
It is understood however that what is described above is given for exemplary and non-limiting purposes, therefore, possible variants of detail that may be required for technical and/or functional reasons are considered from now as to fall within the same protective scope defined by the hereinafter reported claims.

Claims

Wrapping machine (100) for wrapping a palletised load (500) comprising, a wrapping apparatus (30) configured to support and unwind a reel (520) of protective packaging material (510) in particular an extensible film to be wrapped around a side surface (504) of the palletised load (500), a positioning device (20) of a cover sheet (530), said cover sheet (530) being adapted to cover an upper surface (505) of the palletised load (500) and comprising side portions ( 531) which protrude from said upper surface (505) and which fold downwards near the side surface (504) in particular along fold lines (531a) at edges (505a) of said upper surface (505),characterised in that the wrapping machine (100) further comprises a pressor device (40) for retaining the cover sheet (530) on the upper surface (505) of the palletised load (500), preferably exerting a vertical direction force and comprises lifting means (200) for lifting the side portions (531) of the cover sheet (530) moving them away from the side surface (504) of the palletised load (500).
Wrapping machine (100) according to claim 1, wherein the lifting means (200) are positioned at one or more sides of the palletised load (500), in particular at each of the side portions (531) of the cover sheet (530).
Wrapping machine (100) according to any one of the preceding claims, wherein the lifting means (200) rotate each of the side portions (531) of the cover sheet (530) around the fold lines (531a), preferably bringing said side portions (531) to a substantially horizontal position.
Wrapping machine (100) according to any one of the preceding claims, wherein the lifting means (200) comprise blowing elements (201), preferably positioned below the side portions (531) of the cover sheet (530), preferably powered by compressed air, adapted to emit an air blow.
Wrapping machine (100) according to claim 4, wherein the blowing elements (201), are positioned near a base (502) of the palletised load (500), so as to emit an upward air blow and preferably positioned below movement means (10).
Wrapping machine (100) according to any one of the preceding claims, wherein the pressor device (40) comprises a preferably planar support body (45) adapted to rest on the upper surface (505).
Wrapping machine (100) according to claim 6, wherein the support body (45) has a dimension greater than the upper surface (505), so that when the pressor device (40) is in the operating position, a perimeter portion thereof protruding from the upper surface (505) defines abutment means (41).
Wrapping machine (100) according to any one of claims 6 to 7, wherein the support body (45) has dimensions lower than or equal to the upper surface (505) and preferably comprises abutment means (41) extending so as to protrude from the upper surface (505) of the palletized load (500) when the pressor device (40) is in the operating position and said abutment means (41) are movable between a retracted position (R) and an extended position (E).
Wrapping machine (100) according to any one of claims 6 to 8 wherein the support body (45) comprises retaining means, for retaining the side portions (531) of the cover sheet (530) in a substantially horizontal position preferably said retaining means, are positioned at and below the abutment means (41) to retain the side portions (531) interposed between them.
Wrapping machine (100) according to claim 9, wherein the retaining means, are movable between an operating position in which they retain the side portions (531) of the cover sheet (530) in a substantially horizontal position and a non-operating position in which they release them.
Wrapping machine (100) according to any one of claims 6 to 10, comprising lowering means (202), preferably installed on the support body (45) for folding the side portions (531) downwards near the side surface (504), in particular along fold lines (531a) at edges (505a) said lowering means (202), preferably comprise second blowing elements (203), preferably powered by compressed air, adapted to emit an air blow.
Method carried out by the machine (100) according to claim 1, which involves performing the wrapping of a palletised load (500) by means of a protective packaging material (510) in particular an extensible film to wrap a side surface (504) and by means of a cover sheet (530) to cover an upper surface (505) of the palletised load (500) comprising side portions (531) protruding from said upper surface (505) and folding downwards near said side surface (504), in particular along fold lines (531a) at edges (505a) of said upper surface (505), and while performing said wrapping it involves pressing the upper surface (505) of the palletised load (500) with a support body (45), said method involves performing a wrapping comprising a first wrapping cycle to wrap part or all of the side surface (504), up to near the upper surface (505) without encompassing the side portions (531) of the cover sheet (530), and a second wrapping cycle which involves wrapping the side surface (504) so that the protective packaging material (510) covers the side portions (531) of the cover sheet (530), characterised in that said method involves not detaching the support body (45) from the upper surface (505) of the palletised load (500) while performing the entire wrapping.
Method according to claim 12, which involves performing the wrapping of the palletised load (500) according to the following steps:
- positioning the cover sheet (530) on the upper surface (505) of the palletised load (500),

- positioning the pressor device (40) with support body (45) at the upper surface (505) to retain the cover sheet (530) and pressing onto the palletised load (500),

- lifting the side portions (531) of the cover sheet (530) and retaining them in a substantially horizontal position,

- performing a first wrapping cycle that involves wrapping part or all of the side surface (504), in particular so that the protective packaging material (510), covers the upper side area of the palletised load (500), up to near the upper surface (505),

- without moving the support body (45), releasing said side portions (531) of the cover sheet (530), so that they fold downwards near the side surface (504),

- performing a second wrapping cycle, which involves wrapping the side surface (504) so that the protective packaging material (510) covers the side portions (531) of the cover sheet (530),

- lifting the support body (45) from the upper surface (505) and evacuating the palletised load (500).
Method according to any one of claims 12 to 13, which involves lifting the side portions (531) of the cover sheet (530) by blowing air from below towards said side portions (531) and preferably involves releasing and folding the side portions (531) downwards near the side surface (504), in particular along fold lines (531a) at edges (505a) by blowing air from above towards said side portions (531).
Method according to any one of claims 12 to 14, wherein the first and/or second wrapping cycle occurs by rotating the palletised load (500).