Winding machine and winding method

Description

Winding machine and winding method The invention relates to machines and methods for wrapping a load with a film or foil of plastic material or a tape of paper material. It is well known in the packaging sector to wrap a load consisting of a single product or a plurality of products grouped and / or stacked on a pallet, a pallet or a pallet with a plastic film or a paper tape. Known wrapping machines comprise an unwinding unit that moves parallel to and / or around a winding axis and supports a reel of film or tape from which the film or tape is unwound to be wrapped around the load to form a series of bands or strips, generally with a helical shape, thanks to the combination of relative linear and rotational movements between the unwinding unit and the load. In wrapping machines equipped with a rotating load support table or platform, the load is rotated around a vertical winding axis (passing through the center of the table), while the unwinding unit is moved vertically with a reciprocating motion along a support column. In rotating-arm wrapping machines, the load remains fixed while the unwinding unit is moved relative to it, both by rotation around a vertical winding axis and by translation parallel to it, specifically along the vertical portion of the arm. The load is arranged inside the machine in a work area, aligned with the winding axis. Self-propelled wrapping machines, also known as self-propelled wrapping robots, are also known, configured to rotate around the load to wrap it with film or tape. These self-propelled wrapping machines include a carriage or wagon that supports a vertical upright along which the film or tape unwinding unit moves in a rectilinear, alternating motion. The wagon is typically equipped with motorized rear drive wheels and a front steering device that includes one or more steering wheels, controlled by a steering system. The steering system can be operated via a guide bar by an operator to manually guide the machine in a maneuvering configuration, or by a feeler element capable of following the profile or external shape of the load in a working configuration, in which the self-propelled machine rotates autonomously and automatically around the load to wrap it with film. In the simplest embodiments of turntable and rotating arm machines, as well as in the case of self-propelled wrapping machines, before the start of the wrapping or wrapping cycle an initial edge of the film or tape is fixed by an operator. R001.PAT.2283.IT to the load, in particular to the pallet on which the product is placed or the plurality of grouped and / or overlapping products that form the load. Automatic turntable and rotating arm wrapping machines feature gripping devices that grasp and hold the film or tape in the area between the unwinding unit and the load at the end of the wrapping process, and fastening / welding and cutting devices that secure and separate one end of the film from the load. More specifically, after cutting, a first end of the film or tape is held by the gripping device, while a second end is secured by a fastening / welding element to the film or tape already wrapped around the load. The first end of the film or tape is held by the gripping device at least during the initial wrapping phase of a subsequent load placed on the turntable. The gripping device is generally attached to a peripheral edge of the turntable or conveyor supporting the load. However, these gripping and fastening / welding and cutting devices are quite expensive and bulky and, in the case of rotary table machines, limit the accessibility of the table itself by the load. Also known are wrapping machines equipped with unwinding units equipped with blowing means configured to emit air blasts directed towards the load and capable of pushing an initial edge of film or tape exiting the unwinding unit towards and against the load so as to adhere to and / or hook onto the latter to allow the wrapping cycle to start. This solution allows the initial wrapping phase to be made almost automatic, especially in a self-propelled wrapping machine. However, the adhesion or anchoring of the film or tape to the load pushed by air blasts, even if previously electrostatically charged and / or covered with adhesive or glue, is problematic and unreliable, particularly in the case of unfavorable environmental conditions (high humidity, drafts). An object of the invention is to improve known machines and methods for wrapping a load with a plastic film of stretch material. Another object of the invention is to provide a wrapping machine and a wrapping method that allow a leading edge of film or tape to be automatically, reliably and safely attached to a load to initiate a wrapping cycle of the latter, regardless of environmental conditions. R001.PAT.2283.IT A further aim is to develop a winding machine and a method that allow operations to be performed on the film or tape during winding, such as printing text and images, applying labels, etc. Another goal is to create a wrapping machine that is reliable in operation and low in cost. In a first aspect of the invention, a wrapping machine according to claim 1 is provided. In a second aspect of the invention there is provided a method for wrapping a load according to claim 14. The invention will be better understood and implemented by referring to the attached drawings, which illustrate exemplary and non-limiting embodiments, in which: - Figure 1 is a perspective view of a wrapping machine according to the invention of the rotary table type, associated with a load to be wrapped and provided with an operating arm fixed to an unwinding unit and arranged in a non-operating position; - figure 2 is a top plan view of the wrapping machine of figure 1; - Figure 3 is a top plan view of the wrapping machine of Figure 1 in which the operating arm is arranged in the operating position against a wall of the load; - Figure 4 is an enlarged and partial perspective view of the wrapping machine of Figure 3 with the operating arm arranged in the operating position; - figure 5 is a side view of the wrapping machine of figure 4; - Figures 6 and 7 are top plan views of a variant of the rotary table wrapping machine of Figure 1 in which the operating arm is fixed to a support element of the unwinding unit and arranged in the non-operating position and in the operating position respectively; - Figure 8 is an enlarged and partial perspective view of the wrapping machine of Figure 7 with the operating arm arranged in the operating position; - Figure 9 is a perspective view of a rotating arm type wrapping machine according to the invention associated with a load to be wrapped and provided with an operating arm fixed to an unwinding unit and arranged in a non-operating position; - Figure 10 is a partial, enlarged perspective view of the wrapping machine of Figure 9 showing in particular the operating arm in the non-operating position; - Figure 11 is a partial, enlarged perspective view of the wrapping machine of Figure 9 showing in particular the operating arm in the operating position; R001.PAT.2283.IT - figure 12 is a partial side view of the wrapping machine of figure 11; - Figure 13 is a partial top plan view of the wrapping machine of Figure 11 in which the operating arm is arranged in the operating position and, shown in the dotted line, in the non-operating position; - Figures 14 and 15 are partial and enlarged perspective views of a variant of the rotating arm wrapping machine of Figure 9 in which the operating arm is fixed to a support element of the unwinding unit and is arranged in the non-operating position and in the operating position respectively; - Figure 16 is a perspective view of a self-propelled wrapping machine according to the invention associated with a load to be wrapped and provided with an operating arm fixed to an unwinding unit and arranged in a non-operating position; - Figure 17 is a top plan view of the self-propelled wrapping machine of Figure 16; - Figure 18 is a top plan view of the self-propelled wrapping machine of Figure 16 in which the operating arm is arranged in the operating position against a wall of the load; - figure 19 is a side view of the wrapping machine of figure 16; - Figures 20 and 21 are top plan views of a variant of the self-propelled wrapping machine of Figure 16 in which the operating arm is fixed to a support element of the unwinding unit and is arranged in the operating position and in the non-operating position respectively; - figure 22 is a side view of the wrapping machine of figure 20; - Figure 23 is a perspective view of the wrapping machine of Figure 20. With reference to figures 1 to 23, a wrapping machine 1 according to the invention is illustrated, suitable for wrapping a load 100 with a film or tape 50 of plastic and / or paper material and comprising an unwinding unit 2 equipped with a reel 51 of film or tape 50 and roller means 20 suitable for at least unwinding and dispensing the film or tape 50, a support element 3; 13, 23 for slidingly supporting the unwinding unit 2 movable along a winding direction T, in particular almost vertical, and movement means 5; 15; 25 for moving the unwinding unit 2 and the load 100 around each other for a plurality of winding turns. The wrapping machine 1 also comprises blowing means 4 positioned downstream of the roller means 20, with reference to an unwinding direction of the film or tape 50, and R001.PAT.2283.IT configured to emit air blasts designed to push and transfer at least one leading edge 52 of the film or tape 50 unwound from the reel 51 against a wall 101 of the load 100. The wrapping machine also includes an operating arm 6; 16 provided with a working end 7; 17 suitable for supporting at least adhesion means 10 and movable into an operating position A in which the adhesion means 10 are in contact with, or are close to, the film or tape 50 exiting the unwinding unit 2, pushed by the air blasts, and are adjacent to and / or abutting the wall 101 of the load 101 to associate at least the initial edge 52 of the film or tape 50 with the latter. In particular, in the embodiment illustrated in figures 1 to 5, the winding machine 1 of the invention is of the type with a turntable or rotating platform, i.e. the movement means comprise a rotating table 5 which is adjacent to the support element 3, called column or pole, and suitable for receiving and supporting the load 100. The table 5 rotates around a winding axis Z, in particular almost vertical. The working arm 16 is movable, in particular in rotation around a first axis of rotation X1, between the operating position A (figs. 3-5) and a non-operating position B (figs. 1 and 2), in which the working end 17 is spaced from the load 100 and from the film or tape 50 unwound and dispensed by the unwinding unit 2. The first axis of rotation X1 is for example almost parallel to the winding direction T. In the illustrated embodiment, the operating arm 16 is connected to, and supported by, the unwinding unit 2 and comprises, for example, an articulated arm having at least two sections 16a, 16b rotatably connected to each other about a second rotation axis X2, parallel to the first rotation axis X1. More precisely, the operating arm 16 is connected by means of bracket means 30 to a portion of the unwinding unit 2 comprising an outlet opening 21 through which the film or tape 50 is dispensed. As illustrated in figures 1 and 2, in the non-operating position B, the operating arm 16 is folded back on itself, with the two sections 16a, 16b substantially facing each other and adjacent to a side wall of the unwinding unit 2. A first section 16a comprises the operating end 17, a second section 16b is instead connected via the bracket means 30 to the unwinding unit 2. Each section 16 is formed, for example, by a plurality of rectilinear elements that form a quadrangular frame. More precisely, each section 16 is formed by three vertical elements or uprights (two external and one central) and by two horizontal elements or crosspieces that join and connect the ends of the uprights. The working end 17 of the operating arm 16 therefore comprises the external upright of the first section 16a plus R001.PAT.2283.IT away (in operating position A) from the unwinding unit 2. In the operating position A, illustrated in figures 3 -5, the operating arm 16 is deployed so that the working end 17, supporting the adhesion means 10, is adjacent to and / or abuts a wall 101 of the load 100. First actuator means 31, of a known type and not described in further detail, are provided to move the operating arm 16 between the non-operating position B and the operating position A and vice versa, in particular to rotate the first section 16a around the first rotation axis X1 and the second section around the second rotation axis X2. The adhesion means 10 comprise, for example, at least one spreading element 11 adapted to spread at least the initial edge 52 on the wall 101. The spreading element 11 comprises a roller or a brush or a pad. In the embodiment illustrated in Figures 1-5, the adhesion means 10 comprise a pair of pads 11 arranged opposite each other on the opposite end portions of the external upright of the first section 16a which forms the working end 17 of the operating arm 16. In the illustrated embodiment, the adhesion means 10 also comprise an electrostatic charge generating device 12 capable of electrostatically charging the film or tape 50, particularly when made of plastic material, or electrostatically charging, alternatively or additionally, the wall 101 of the load 100. The generating device 12 is, for example, a device capable of generating and transferring electrostatic charges onto the film or tape 50 or onto the wall 101 of the load 100 by exploiting electrostatic induction and / or the triboelectric effect. For example, the generating device 12 may comprise one or more charging bars provided with tips powered by high voltage electric current capable of generating positive or negative ions to electrostatically charge the material of the film or tape 50. As is known, the electrostatic charges contribute to achieving the adhesion of the film or tape 50 to the wall 101. Alternatively, the pads or rollers or brushes 11 that spread the film or tape on the wall 100 of the load may be electrostatically charged (by electrostatic induction and / or triboelectric effect) so as to transfer electrostatic charges to the film or tape 50 and allow its adhesion to the wall 100. Alternatively, the adhesion means 10 may comprise the spreading elements 11 or the electrostatic charge generating device 12. The electrostatic charge generating device 12 can be controlled, for example by a management and control unit of the wrapping machine 1, to regulate the electrostatic charge to be created on the film or tape. In particular, the power of R001.PAT.2283.IT power supply of the generating device 12 and its operating duration depend not only on the type of material of the film or tape 50 and the products to be wrapped, but also on the environmental conditions (temperature, humidity, air currents) of the room in which the wrapping machine 1 operates. To this end, the wrapping machine 1 may include sensors capable of detecting environmental conditions, in particular humidity, temperature, air currents, so as to appropriately modify the power supply of the generating device 12 and the duration of its operation. For example, in the case of dry air, i.e. with very low residual humidity, the film or tape 50, especially if made of plastic material, tends to become electrostatically charged very easily and therefore a lower power supply and a shorter operating time of the electrostatic charging generating device 12 are required.This allows for reduced energy consumption during the load wrapping cycle. Additionally or alternatively, the adhesion means 10 may comprise one or more gluing devices 18 configured to deliver adhesive or glue at least to the leading edge 52 of film or tape 50 and / or to the wall 101 of the load 100 to enable firm adhesion of the leading edge 52 of film to the load, particularly in the initial phase of the wrapping cycle. The gluing devices 18 provided on the operating arm 16 may also be used during a wrapping cycle, typically with paper tape, to secure the various strips of tape together as they are wrapped around the load. The adhesion means 10 may further comprise one or more sealing devices 19 configured to seal, for example thermally or ultrasonically, and thereby secure an end flap of the film or tape 50 onto the bands or strips of film or tape already wrapped around the load 100 at the end of the wrapping cycle. With particular reference to figure 5, the blowing means 4 are fixed to the unwinding unit 2 at its outlet opening 21 through which the film or tape 50 unwound from the reel 51 is dispensed and exits. In the illustrated embodiment, the blowing means 4 comprises a plurality of blowing devices 41 arranged along two parallel rows on opposite sides of the outlet opening 21, i.e., on opposite sides of the film or web 50. The blowing devices 41 are configured to emit air puffs towards the load 100 and towards the leading edge 52 of film so as to push and guide the latter along an unwinding direction S towards a wall of the load itself. The blowing means 41 are for example fans driven by respective electric motors. It is also envisaged that the winding machine 1 includes additional blowing means 14 R001.PAT.2283.IT fixed to the operating arm 16, in particular at its working end 17 and arranged to emit further blasts of air capable of maintaining at least the initial edge 52 of film or tape 50 adhering to the wall 101 of the load 100, thus cooperating with the adhesion means 10. Again, the additional blowing means 14 may comprise a plurality of additional blowing devices 42 arranged along two parallel rows on opposite sides of the operating arm 16, preferably at its operating end 17. The wrapping machine 1 of the invention may further include printing means 28 attached to the working end 17 of the working arm 16 and arranged to make graphic prints on the film or tape 50 applied to the load 100. The wrapping machine 1 of the invention may further include labeling means 29 attached to the working end 17 of the working arm 16 and arranged to apply adhesive labels or tags to the film or tape 50 applied to the load 100. The operation of the turntable wrapping machine 1 of the invention involves, in an initial phase, the activation of the blowing means 4 to deliver air blasts and the actuation of the roller means 20 to unwind an initial edge 52 of film or tape 50 from the reel 51 and move it through the exit opening 21 of the unwinding unit 2. The initial edge 52 of film or tape exiting the unwinding unit is hit by the air blasts and then pushed and transferred towards the load 100 and against one of its walls 101. The operating arm 16, initially arranged in the non-operating position B in which it is folded back on itself, is then moved by the first actuator means 31 into the operating position A in such a way that the adhesion means 10 are in contact with, or close to, the film or tape 50 and are adjacent to and / or abutting the wall 101 of the load 101 to associate at least the initial edge 52 of the film or tape 50 with the latter. More precisely, the initial edge 52 of film is, for example, electrostatically charged by the electrostatic charge generating device 12 and pressed and stretched on the wall 101 of the load by the pads 11, progressively during the rotation of the turntable 5 which is suitably moved. In this way, the initial edge 52 of film adheres and attaches to the load 100 to allow the film to gradually wrap around the load 100. During the rotation of the latter, successive strips of film or tape 50, dispensed by the unwinding unit 2, overlap, blocking it, on the initial edge 52. In this way, once the film or tape 50 is firmly fixed to the load, the rotation speed of the turntable 5 can be increased and with it the winding tension of the film or tape 50 around the load until the latter is completely wrapped. R001.PAT.2283.IT With reference to figures 7 to 8, a variant of the rotating table wrapping machine 1 is illustrated which differs from the embodiment described above and illustrated in figures 1 to 5 in that the articulated operating arm 16, formed by two sections 16a, 16b, is connected to, and supported by, the support element 3. More precisely, the operating arm 16 is connected to one side of the support element 3, for example the one facing the rotating table 5, so that it can rotate around the first rotation axis X1. Alternatively, the operating arm 16 can also be slidably connected to the support element 3 so as to vary its height from the ground and allow the initial edge 52 of film or tape to be fixed in different positions (heights) on the load 100. The operating arm 16 can be moved along the support element 3 manually or by means of opposite actuator means of a known type, for example similar to those which move the unwinding unit 2 along the support element 3 according to the winding direction T. The operation of this variant of the turntable wrapping machine 1 is substantially identical to that of the wrapping machine 1 described above and having the operating arm 16 fixed to the unwinding unit 2. With reference to figures 9 to 13, another embodiment of the winding machine 1 of the invention is illustrated, in particular, of the rotating arm type, i.e. with the movement means comprising a rotating arm 15 which supports the support element 13 and is rotatable around a winding axis Z, in particular vertical, so as to cause the support element 13 and the unwinding unit 2, moved along it around the load 100, to rotate. The rotating arm 15, of a known type, is arranged almost horizontally and is rotatably supported around the winding axis Z by a support frame 16 of the winding machine 1. In this embodiment, the operating arm 6 comprises a single section 6a connected to the unwinding unit 2 rotatable around the first rotation axis X1 by means of bracket means 30. In particular, the operating arm 6 is connected to the portion of the unwinding unit 2 at the outlet opening 21 through which the film or tape 50 is dispensed. As illustrated in figures 9 and 10 in the non-operating position B the operating arm 6 is rotated towards the unwinding unit 2 further away from the load 100. In the operating position A, illustrated in figures 11-13, the operating arm 6 is rotated R001.PAT.2283.IT towards the load 100 in such a way that the working end 7, supporting the adhesion means 10, is adjacent to and / or abuts a wall 101 of the aforementioned load 100. Section 6a is made up of a plurality of rectilinear elements that form a quadrangular frame. Specifically, section 6a is made up of three vertical elements or uprights (two external and one central) and two horizontal elements or crosspieces that connect and join the ends of the uprights. The working end 7 of the operating arm 6 comprises the external upright of section 6a furthest from the unwinding unit 2, the remaining external upright being rotatably connected to the bracket means 30. First actuator means 31, of a known type and not described in further detail, are provided to rotate the operating arm 16 around the first rotation axis X1 between the non-operating position B and the operating position A and vice versa. Also in this embodiment of the wrapping machine of the invention, the adhesion means 10 comprise, for example, one or more spreading elements 11 suitable for stretching at least the initial flap 52 on the wall 101 (for example a pair of pads 11 arranged on the opposite terminal portions of the external upright section 6a which forms the working end 7 of the operating arm 6) and a generating device 12 suitable for electrostatically charging the film or tape 50 and alternatively or in addition the wall 101 of the load 100. With particular reference to Figure 12, the blowing means 4 are fixed to the unwinding unit 2 at its outlet opening 21 through which the film or tape 50 unwound from the reel 51 is dispensed and exits. The blowing means 4 comprise a plurality of blowing devices 41 arranged along two parallel rows on opposite sides of the outlet opening 21 so as to emit air blasts capable of pushing and guiding the leading edge 52 of film or tape towards and against a wall 101 of the load 100. The operation of the rotating arm wrapping machine 1 of the invention involves, in an initial phase, the activation of the blowing means 4 to deliver air blasts and the actuation of the roller means 20 to unwind an initial edge 52 of film or tape 50 from the reel 51 and move it through the exit opening 21 of the unwinding unit 2. The initial edge 52 of film or tape exiting from the unwinding unit 2 is hit by the air blasts and then pushed and transferred towards the load 100, in particular against one of its walls 101. The operating arm 6, initially arranged in the non-operating position B, is then rotated by the first actuator means 31 into the operating position A such that the adhesion means 10 are in contact with, or close to, the film or tape 50 and are adjacent and / or R001.PAT.2283.IT contact with the wall 101 of the load 101 to associate with the latter at least the initial edge 52 of the film or tape 50. More precisely, the initial film edge 52 is, for example, electrostatically charged by the electrostatic charge generating device 12 and pressed and stretched on the wall 101 of the load by the pads 11, progressively during the rotation of the rotating arm 15 around the winding axis Z. In this way the initial film edge 52 adheres and attaches to the load 100 to allow the film to gradually wrap around the load 100. During the rotation of the rotating arm 15 and the unwinding unit 2, successive bands of film or tape 50, dispensed by the unwinding unit 2, overlap, blocking it, with the initial film edge 52. In this way, once the film or tape 50 is firmly fixed to the load, the rotation speed of the rotating arm 15 and the unwinding unit 2 can be increased and with it the winding tension of the film or tape 50 around the load 100 until the latter is completely wrapped. Figures 14 and 15 illustrate a variant of the rotating arm wrapping machine 1 which differs from the embodiment described above and illustrated in Figures 9 to 13 in that the operating arm 16, in addition to being connected to, and supported by, the support element 13 around the first rotation axis X1, is of the articulated type and comprises two sections 16a, 16b rotatably connected to each other around a second rotation axis X2, parallel to the first rotation axis X1. More precisely, the operating arm 16 is connected to one side of the support element 3, for example the one facing the load 100, so that it can rotate around the first rotation axis X1. As illustrated in figure 14, in the non-operating position B the operating arm 16 is folded back on itself, with the two sections 16a, 16b substantially facing each other and adjacent to a side wall of the unwinding unit 2. The first section 16a comprises the operating end 17, the second section 16b is instead connected to the support element 13. Each section 16 is made up of a plurality of rectilinear elements that form a quadrangular frame. More precisely, each section 16 is made up of three vertical elements or uprights (two external and one central) and two horizontal elements or crosspieces that join and connect the ends of the uprights. The working end 17 of the operating arm 16 therefore comprises the external upright of the first section 16a furthest (in the operating position A) from the unwinding unit 2. In the operating position A (fig. 15), the operating arm 16 is deployed in such a way that the working end 17, supporting the adhesion means 10, is adjacent to and / or abuts R001.PAT.2283.IT a wall 101 of load 100. It is envisaged that the operating arm 16 can also be connected in a sliding manner to the support element 13 so as to vary its height from the ground and allow the initial edge 52 of film or tape to be fixed in different positions (heights) on the load 100. The operating arm 16 can be moved along the support element 13 manually or by means of opposite actuator means of a known type, for example similar to those which move the unwinding unit 2 along the support element 13 according to the winding direction T. This variant of the rotating arm wrapping machine 1 also differs from the embodiment described above and illustrated in figures 9 to 13 in that the adhesion means 10 supported by the articulated operating arm 16 also comprise a welding device 19 configured to weld and therefore fix a terminal edge of the film or tape 50 onto the bands or strips of film or tape 50 already wrapped around the load 100 at the end of the wrapping cycle. The operation of this variant of the rotary arm wrapping machine 1 is substantially identical to that of the rotary arm wrapping machine 1 described above and illustrated in figures 9 to 13 and having the operating arm 6 fixed to the unwinding unit 2. With reference to figures 16 to 19, another embodiment of the wrapping machine 1 of the invention is illustrated, in particular of the self-propelled type, also called a wrapping robot, in which the movement means comprise a self-propelled carriage or trolley 25 to which the support element 23 is fixed and which is provided with at least one traction wheel 26 and guide means 27 to direct the carriage 2 so that it rotates around the load 100 for a plurality of wrapping revolutions during a wrapping cycle. The unwinding unit 2 is moved along the support element 23 in the winding direction T. Also in this embodiment, the operating arm 6 is connected to, and supported by, the unwinding unit 2, in particular it comprises a single section 6a connected to the unwinding unit 2 rotatable about the first axis of rotation X1 by bracket means 30. In particular, the operating arm 6 is rotatably fixed to the portion of the unwinding unit 2 which comprises the outlet opening 21 through which the film or tape 50 is dispensed. As illustrated in figures 16 and 17 in the non-operating position B the operating arm 6 is rotated towards the unwinding unit 2 further away from the load 100. R001.PAT.2283.IT In the operating position A, illustrated in figures 18 and 19, the operating arm 6 is rotated towards the load 100 in such a way that the working end 7, supporting the adhesion means 10, is adjacent to and / or abuts a wall 101 of the aforementioned load 100. Section 6a is made up of a plurality of rectilinear elements that form a quadrangular frame. Specifically, section 6a is made up of three vertical elements or uprights (two external and one central) and two horizontal elements or crosspieces that connect and join the ends of the uprights. The working end 7 of the operating arm 6 comprises the external upright of section 6a furthest from the unwinding unit 2, the remaining external upright being rotatably connected to the bracket means 30. First actuator means 31, of a known type and not described in further detail, are provided to rotate the operating arm 6 around the first rotation axis X1 between the non-operating position B and the operating position A and vice versa. Also in this embodiment of the wrapping machine of the invention, the adhesion means 10 comprise, for example, one or more spreading elements 11 suitable for spreading at least the initial flap 52 on the wall 101 (for example a pair of pads 11 arranged on the opposite terminal portions of the external upright section 6a which forms the working end 7 of the operating arm 6) and a generating device 12 suitable for electrostatically charging the film or tape 50 and alternatively or in addition the wall 101 of the load 100. With particular reference to Figure 19, the blowing means 4 are fixed to the unwinding unit 2 at its outlet opening 21 through which the film or tape 50 unwound from the reel 51 is dispensed and exits. The blowing means 4 comprise a plurality of blowing devices 41 arranged along two parallel rows on opposite sides of the outlet opening 21 so as to emit air blasts capable of pushing and guiding the leading edge 52 of film or tape towards and against a wall 101 of the load 100. The self-propelled wrapping machine 1 comprises further blowing means 14 fixed to the working arm 6, in particular adjacent to its working end 7 so as to emit further blasts of air capable of maintaining at least the initial edge 52 of film or tape 50 adhering to the wall 101 of the load 100, thus cooperating with the adhesion means 10. The further blowing means 14 comprise a plurality of further blowing devices 42 arranged along two parallel rows on opposite sides of the working arm 6, for example fixed to the central upright of the section 6a. The wrapping machine 1 of the invention further includes printing means 28 fixed R001.PAT.2283.IT at the working end 17 of the operating arm 16 and arranged to perform graphic prints on the film or tape 50 applied to the load 100. The operation of the self-propelled wrapping machine 1 of the invention involves, in an initial phase, the activation of the blowing means 4 and of the further blowing means 14 to deliver air blasts and the actuation of the roller means 20 to unwind from the reel 51 an initial edge 52 of film or tape 50 and move it through the exit opening 21 of the unwinding unit 2. The initial edge 52 of film or tape exiting from the unwinding unit 2 is hit by the air blasts and then pushed and transferred towards the load 100, in particular against one of its walls 101. The operating arm 6 initially arranged in the non-operating position B is then rotated by the first actuator means 31 into the operating position A such that the adhesion means 10 are in contact with, or close to, the film or tape 50 and are adjacent to and / or abutting the wall 101 of the load 101 to associate at least the initial edge 52 of the film or tape 50 with the latter. More precisely, the initial edge 52 of film is, for example, electrostatically charged by the electrostatic charge generating device 12 and pressed and stretched onto the wall 101 of the load 100 by the spreading elements 11, progressively during the rotation of the self-propelled wrapping machine around the load 100. In this way the initial edge 52 of film adheres and attaches to the load 100 to allow the film to gradually wrap around the load 100. During the rotation of the self-propelled wrapping machine 1, successive strips or bands of film or tape 50, dispensed by the unwinding unit 2, overlap, blocking it, with the initial edge 52 of film or tape. In this way, once the film or tape 50 is firmly fixed to the load, the rotation speed of the self-propelled carriage 25 can be increased and with it the winding tension of the film or tape 50 around the load until the latter is completely wrapped. With reference to figures 20 to 23, a variant of the self-propelled wrapping machine 1 is illustrated which differs from the embodiment described above and illustrated in figures 16 to 19 in that the operating arm 16 is of the articulated type, formed by two sections 16a, 16b, and is connected to, and supported by, the support element 23. More precisely, the operating arm 16 is connected to one side of the support element 23, for example the one facing the load 100, so that it can rotate around the first axis of rotation X1. R001.PAT.2283.IT Alternatively, the operating arm 16 can also be slidably connected to the support element 23 so as to vary its height from the ground and allow the initial edge 52 of film or tape to be fixed in different positions (heights) on the load 100. The operating arm 16 can be moved along the support element 23 by means of opposite actuator means of a known type, for example similar to those which move the unwinding unit 2 along the support element 23 in the winding direction T. This variant of the self-propelled wrapping machine 1 of the invention also differs from the embodiment described above and illustrated in figures 16 to 19 in that the adhesion means 10 comprise one or more spreading elements 11 capable of spreading at least the initial flap 52 on the wall 101 (for example a pair of pads 11 arranged on the opposite end portions of the external upright section 6a which forms the working end 7 of the operating arm 6) and in place of the electrostatic charge generating device 12 a gluing device 18 configured to dispense adhesive or glue at least on the initial flap 52 of 50 and / or on the wall 101 of the load 100, in particular in the case in which the film or tape is made of paper material. The gluing device 18 may also be used by holding the operating arm in operating position A during a paper wrapping cycle to secure the various strips of film or tape together as they are wrapped around the load. The wrapping machine 1 of the invention further includes labeling means 29 attached to the working end 17 of the working arm 16 and arranged to apply adhesive labels or tags to the film or tape 50 applied to the load 100. The operation of this variant of the self-propelled wrapping machine 1 is substantially identical to that of the self-propelled wrapping machine 1 described above and having the operating arm 6 fixed to the unwinding unit 2. The invention also concerns a method for wrapping the load 100 with a film or tape 50 of plastic and / or paper material using the wrapping machine 1 described above and illustrated in figures 1 to 23. In particular, the wrapping method comprises the steps of: - unwinding said film or tape 50 from a reel 51 by means of roller means 20 and releasing an initial edge 52 of film 50 exiting from the unwinding unit 2; - emitting air blasts by blowing means 4; 14 to push and guide the leading edge 52 of film or tape towards and against a wall 101 of the load 100; - move into operating position A an operating arm 6; 16 so that adhesion means 10 supported by a working end 7; 17 of the operating arm 6; 16 are R001.PAT.2283.IT in contact with, or close to, the film or tape 50 and adjacent to and / or abutting the wall 101 of the load 100 to associate with the latter at least the initial edge 52 of the film or tape 50; - start a wrapping cycle. The joining step comprises spreading at least the initial edge 52 of film or tape on the wall 101 by means of at least one spreading element 11 of the adhesion means 10, in particular the spreading element 11 comprising a roller or a brush or a pad. The joining step also comprises electrostatically adhering at least the initial edge 52 of film or tape 50 to the wall 101 of the load 100 by electrostatically charging the film or tape 50 by means of at least one electrostatic charge generating device 12 of the adhesion means 10. The joining step further comprises fixing at least the initial edge 52 of film or tape 50 to the wall 101 of the load 100 by means of adhesive or glue dispensed at least onto the initial edge 52 of film or tape 50 and / or onto the wall 101 by at least one gluing device 18 of the adhesion means 10. The method also provides for moving the operating arm 6; 16 to the non-operating position B after a defined operating time during the winding cycle. Thanks to the wrapping machine 1 and the wrapping method of the invention, it is therefore possible to automatically attach a leading edge 52a of film or tape to a wall 101 of the load 100 so as to begin a wrapping cycle reliably and safely without operator intervention, particularly regardless of environmental conditions. In particular, by means of the air blasts delivered by the blowing means 4, the leading edge 52 of the film or tape, unwound from the reel by the roller means 20 and moved out through the exit opening 21 of the unwinding unit 2, is pushed and transferred towards the load 100 and against one of its walls 101. The adhesion means 10 supported by the operating arm 16 moved by the first actuator means 31 in the operating position A and thus placed in contact with, or close to, the film or tape 50 and adjacent to and / or abutting the wall 101 of the load 101 allow the initial edge 52 to be electrostatically charged (via the electrostatic charge generating device 12) and to be pressed and stretched on the wall 101 progressively during the relative rotation between the load and the unwinding unit. In this way the initial edge 52 of film adheres and attaches to the load 100 in a firm and reliable manner regardless of the environmental conditions (wind, humidity, etc.) which allows the film or tape 50 to gradually wrap around the load 100. During the rotation of the latter, successive bands of R001.PAT.2283.IT film or tape 50, dispensed by the unwinding unit 2, overlaps, blocking it, to the initial edge 52 of film. In this way, once the film is firmly fixed The operating arm 6, 16 is furthermore capable of supporting a gluing device 18 of the adhesion means configured to dispense adhesive or glue at least onto the leading edge 52 of 5 50 and / or onto the wall 101 of the load 100, in particular in the case where the film or tape is made of paper material. The gluing device 18 may also be used by holding the operating arm in operating position A during a paper wrapping cycle to secure the various strips of film or tape together as they are wrapped around the load.

Claims

1. Wrapping machine (1) for wrapping a load (100) with a film or tape (50) of plastic and / or paper material, comprising: - an unwinding unit (2) provided with a reel (51) of said film or tape (50) and roller means (20) suitable for at least unwinding and dispensing said film or tape (50); - a support element (3; 13, 23) for slidingly supporting said unwinding unit (2) movable along a winding direction (T), in particular almost vertical; - movement means (5; 15; 25) for moving said unwinding unit (2) and said load (100) around each other for a plurality of winding turns; - blowing means (4) configured to emit air blasts capable of pushing and transferring at least one initial edge (52) of said film or tape (50) unwound from said reel (51) and exiting from said unwinding unit (2) against a wall (101) of said load (100); characterised in that it comprises an operating arm (6;16) provided with a working end (7; 17) suitable for supporting at least adhesion means (10) and movable into an operating position (A) in which said adhesion means (10) are in contact with, or close to, said film or tape (50) exiting from said unwinding unit (2) and pushed by said air blasts and are adjacent to and / or abutting said wall (101) of said load (101) to associate with the latter at least said initial edge (52) of said film or tape (50).; 2. Wrapping machine (1) according to claim 1, wherein said operating arm (6; 16) is movable, in particular in rotation around a first rotation axis (X1), between said operating position (A) and a non-operating position (B), wherein said working end (7; 17) is spaced from said load (100) and from said film or tape (50) unwound and dispensed by said unwinding unit (2).

3. Winding machine (1) according to claim 1 or 2, wherein said operating arm (6; 16) is connected to, and supported by, said unwinding unit (2), in particular it is connected to said unwinding unit (2) rotatably around a first axis of rotation (X1), in particular almost parallel to the winding direction (T).

4. Winding machine (1) according to claim 1 or 2, wherein said operating arm (6; 16) is connected to, and supported by, said support element (3; 13, 23), in particular is connected to said support element (3; 13, 23) rotatably around R001.PAT.2283.IT a first axis of rotation (X1), in particular almost parallel to the winding direction (T).

5. Wrapping machine (1) according to one of the preceding claims, wherein said operating arm (16) comprises an articulated arm having at least two sections (16a, 16b) rotatably connected to each other around a second rotation axis (X2).

6. Wrapping machine (1) according to one of the preceding claims, wherein said adhesion means (10) comprise at least one of: spreading element (11) adapted to spread at least said initial edge (52) on said wall (101), in particular said spreading element (11) comprising a roller or a brush or a pad, electrostatic charge generating device (12) adapted to electrostatically charge said film or tape (50) and / or said load (100), gluing device (18) configured to dispense adhesive or glue at least on said initial edge (52) of film or tape (50) and / or on said wall (101) of said load (100), welding device (19) adapted to fix said film or tape (50) on said load (100).

7. Wrapping machine (1) according to one of the preceding claims, wherein said blowing means (4) are fixed to said unwinding unit (2) at an exit opening (21) of the latter through which said film or tape (50) emerges, in particular they are positioned downstream of said roller means (20) with reference to an unwinding direction (S) of said film or tape (50).

8. Wrapping machine (1) according to claim 9, wherein said blowing means (4) comprise a plurality of blowing devices (41) arranged parallel to each other on opposite sides of said film or tape (50).

9. Wrapping machine (1) according to one of the preceding claims, comprising further blowing means (14) fixed to said operating arm (6; 16), in particular at its working end (7; 17), and arranged to emit further air blasts capable of maintaining at least said initial edge (52) of said film or tape (50) adhering to said wall (101) of said load (100).

10. Wrapping machine (1) according to one of the preceding claims, wherein said operating arm (6; 16) is arranged to support at least one of printing means (28) arranged to perform graphic prints on said film or tape (50) applied on said load (100), labelling means (29) arranged to apply labels on the film or tape (50).

11. Winding machine (1) according to one of the preceding claims, wherein said movement means (5; 15; 25) comprise a rotating table (5) adjacent to said support element (3) and suitable for receiving and supporting said load (100), in particular said table (5) being rotatable around a winding axis (Z), in particular vertical.

12. Winding machine (1) according to one of claims 1 to 10, wherein said movement means (5; 15; 25) comprise an arm (15) supporting said support element (13) and rotating around a winding axis (Z), in particular vertical, so as to rotate said support element (13) and said unwinding unit (2) around said load (100).

13. Winding machine (1) according to one of claims 1 to 10, wherein said movement means (5; 15; 25) comprise a self-propelled carriage (25) supporting said support element (23) and provided with at least one traction wheel (26) and guide means (27) to direct said carriage (2) so that the latter during a winding cycle rotates around said load (100) for a plurality of winding turns.

14. A method for wrapping a load (100) with a film or tape (50) of plastic and / or paper material by means of a wrapping machine (1) according to one of the preceding claims comprising: - unwinding said film or tape (50) from a reel (51) by means of roller means (20) and releasing a leading edge (52) of film or tape (50) exiting the unwinding unit (2); - emitting air blasts by means of blowing means (4; 14) to push and guide said leading edge (52) of film or tape towards and against a wall (101) of said load (100); - moving into operating position (A) an operating arm (6; 16) so that adhesion means (10) supported by a working end (7; 17) of said operating arm (6; 16) are in contact with, or close to, said film or tape (50) and adjacent to and / or abutting said wall (101) of said load (100) to associate with the latter at least said initial edge (52) of said film or tape (50);- start a wrapping cycle.; 15. Method according to claim 14, wherein said associating comprises spreading at least said initial flap (52) on said wall (101) by means of at least one spreading element (11) of said adhesion means (10), in particular said spreading element (11) comprising a roller or a brush or a pad.

16. Method according to claim 14 or 15, wherein said associating comprises electrostatically adhering at least said leading edge (52) of said film or tape (50) to said wall (101) by electrostatically charging said film or tape (50) by means of R001.PAT.2283.IT at least one electrostatic charge generating device (12) of said adhesion means (10) and / or comprises fixing at least said leading edge (52) of film or tape (50) to said wall (101) of said load (100) by means of adhesive or glue dispensed at least to said leading edge (52) of film or tape (50) and / or to said wall (101) by at least one gluing device (18) of said adhesion means (10).