Stretching and covering machine with perforator

Abstract

Various embodiments of the present disclosure provide a stretch covering machine and a method of operating the stretch covering machine to perforate a tubular film and wrap an article with the tubular film. The method includes drawing the tubular film from the film roll and perforating the tubular film after the tubular film has been drawn from the film roll so as to form perforations arranged along the length of the tubular film. Using a retraction device, the tubular film is lowered around the article to enclose the article within the interior of the tubular film.

Description

[0001] Priority

[0002] This application claims the benefit and priority of U.S. Provisional Patent Application No. 63 / 429,128, filed Nov. 30, 2022, the entire content of which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to a stretch hood machine for wrapping a load with a tubular stretch film, and more particularly to a stretch hood machine configured to perforate a tubular film and wrap a load with the tubular film. Background Art

[0004] Stretch hood machines use a tubular plastic stretch film to wrap a load. These stretch hood machines include a frame that supports a film supply assembly, a film opening assembly, and a reefing-and-wrapping assembly. The reefing-and-wrapping assembly includes a wrapping carriage that supports four reefing devices. Each reefing device includes a support that supports a drive roller and a vertically extending reefing finger. A motor drives the drive roller, and the reefing finger supports a freely rotatable guide roller. The drive roller is movable toward and away from the guide roller.

[0005] To wrap a load, the film supply assembly pulls a tubular film from a film roll, cuts the film to a desired length to form a tubular film section, and in some cases thermally seals the top of the tubular film section completely closed. The film opening assembly opens the bottom portion of the tubular film section such that its perimeter is generally rectangular. Each reefing device moves laterally inwardly relative to the tubular film section to a respective insertion position, at which the reefing devices form an insertion configuration. Then, the wrapping carriage rises relative to the tubular film section until the reefing fingers of the reefing devices enter the open bottom portion of the tubular film section near the four corners of the bottom portion. Then, the reefing devices move laterally outwardly to respective reefing positions, at which the reefing devices form a reefing configuration in preparation for reefing the tubular film section onto the reefing fingers. The drive roller of the reefing device moves toward its respective guide roller to engage the outer surface of the tubular film section and force the inner surface of the tubular film section against the guide roller, thereby clamping the tubular film between the rollers. The motor drives its respective drive roller in a reefing rotational direction to reef (or gather) the tubular film section onto the reefing fingers.

[0006] After retraction, each retraction device moves laterally outwardly to a respective package position where the retraction devices form a package configuration. Since the film is elastic, the film stretches during this movement. The package configuration (and thus the package positions) is determined based on the size and shape of the load, so the size of the perimeter of the tubular film section is set to surround the load once the retraction devices reach the package configuration. After the retraction devices reach the package configuration, the package carriage descends relative to the load. During this descent, the drive rollers of the retraction devices are driven by a motor to pay out the remainder of the film from the retraction fingers at a pay-out speed in the pay-out rotational direction (opposite to the retraction rotational direction). When this occurs, the film attempts to return to its unstretched size and shape and laterally shrinks onto the load, which integrates the load and / or secures the load to the pallet. This completes the packaging process, and the conveyor transports the load out of the stretch hood machine.

[0007] In some cases, it is desirable to provide ventilation for the load, for example to avoid moisture-related problems. One possible way to provide ventilation is to use a perforated film roll instead of a standard film roll. This provides a passage between the interior of the tubular film and the surrounding environment, which reduces the likelihood of unwanted moisture accumulation. However, the transition between perforated film and standard film can be time-consuming and costly. Summary of the Invention

[0008] Various embodiments of the present disclosure provide methods and stretch hood machines configured to perforate a tubular film and wrap a cargo load with the tubular film.

[0009] In one embodiment, a method of operating a stretch hood machine to wrap an article with a tubular film includes pulling the tubular film from a film roll. The method further includes perforating the tubular film after the tubular film has been pulled from the film roll to form perforations disposed along the length of the tubular film. Further, the method includes retracting the tubular film onto retraction fingers of a plurality of retraction devices and lowering the retraction devices around the article to wrap the article within the interior of the tubular film.

[0010] In one embodiment, a stretch hood machine includes: a machine frame; a package carriage movable relative to the machine frame between an upper position and a lower position; and a plurality of retraction devices supported by the package carriage and configured to wrap a tubular film around an article. A film supply assembly is configured to pull the tubular film from a film roll, cut the tubular film from the roll to form a section of tubular film, and guide the section of tubular film to the retraction devices. The machine further includes a perforator to form perforations disposed along the length of the tubular film after the tubular film has been pulled from the roll and before the retraction devices retract the section of tubular film. Brief Description of the Drawings

[0011] Figure 1 is a perspective view of an embodiment of a stretch sleever of the present disclosure.

[0012] Figure 2 shows Figure 1 a block diagram of certain components of the stretch sleever.

[0013] Figure 3 is Figure 1 a side view of one of the retracting devices of the stretch sleever, where the retracting carriage is in its original position.

[0014] Figure 4 is after the film opening device has opened the bottom of the tubular film section and before the retracting fingers of the retracting device have been inserted into the bottom of the tubular film section, Figure 1 a perspective view of the film opening device and the retracting device of the stretch sleever.

[0015] Figure 5 corresponds to Figure 4 a simplified top plan view.

[0016] Figure 6 is similar to Figure 4 a perspective view, but is after the retracting fingers of the retracting device have been inserted into the bottom of the tubular film section and after the retracting carriage of the retracting device has moved to its corresponding retracting position.

[0017] Figure 7 corresponds to Figure 6 a simplified top plan view.

[0018] Figure 8 corresponds to Figure 6 of Figure 3 a side view of the retracting device.

[0019] Figure 9 is similar to Figure 6 a perspective view, but is after the retracting device has retracted the tubular film section onto its retracting fingers.

[0020] Figure 10 corresponds to Figure 9 of Figure 3 a side view of the retracting device.

[0021] Figure 11 is a perspective view of a tubular film roll.

[0022] Figure 12A is a schematic perspective view of an exemplary embodiment of a perforator of the present disclosure in a first position.

[0023] Figure 12B is Figure 12ASchematic perspective view of the perforator in the second position.

[0024] Figure 13 Is a schematic perspective view of another exemplary embodiment of the perforator of the present disclosure.

[0025] Figure 14A Is a schematic perspective view of another exemplary embodiment of the perforator of the present disclosure in the first position.

[0026] Figure 14B Is Figure 14A Schematic perspective view of the perforator in the second position.

[0027] Figure 15 Is a schematic view of another exemplary embodiment of the perforator of the present disclosure.

[0028] Figure 16 Is a schematic front view of an exemplary embodiment of a section of a perforated tubular film.

[0029] Figure 17 Is a schematic front view of another exemplary embodiment of a section of a perforated tubular film.

[0030] Figure 18 Is a schematic front view of another exemplary embodiment of a section of a perforated tubular film.

[0031] Figure 19 Is a schematic depiction showing a perforated stretch hood that is wrapped around an article. Detailed Description

[0032] Various embodiments of the present disclosure provide a stretch hood machine that is configured to perforate a tubular film and wrap a cargo load with the tubular film. Figures 1 to 10 , Figure 12A , and Figure 12B Illustrates an embodiment of the stretch hood machine 10 of the present disclosure, and an embodiment of the components and parts of the stretch hood machine 10. The stretch hood machine 10 includes a machine frame 100, a film supply assembly 200 supported by the machine frame 100, a film opening assembly 300 supported by the machine frame 100, a retracting and wrapping assembly 400 supported by the machine frame 100, an operator interface 500, and a controller 600. A coordinate system CS (as Figure 1 shown) is used herein as a reference system for the directional movement of a plurality of different components of the stretch hood machine 10 in the X direction, the Y direction, and the Z direction (which are perpendicular to each other in this exemplary embodiment).

[0033] The machine frame 100 is formed by a plurality of tubular and / or solid members and other elements (not individually labeled) and is configured to support the other components and parts of the stretch hooding machine 10. The machine frame 100 defines an enclosure area inside thereof and has a feed area (not labeled) and a discharge area (not labeled), at the feed area where a pallet load (such as the load L on the pallet P) is conveyed into the enclosure area for wrapping, and at the discharge area where the pallet load is conveyed out of the enclosure area after wrapping. The machine frame 100 shown is merely an exemplary configuration and any suitable configuration may be employed.

[0034] The film supply assembly 200 includes suitable components that are configured to form a section of tubular film 40 (shown in Figure 11 ), and then the stretch hooding machine 10 uses this section of tubular film to wrap the load L. More specifically, and as is known in the art, the film supply assembly 200 includes components suitable for pulling a length of tubular film 40 from a roll of tubular film R rotatably mounted to the machine frame 100, cutting this length of tubular film 40 from the roll R to form a section of tubular film 40, and optionally perforating a portion of the tubular film 40, as described in more detail below. When pulling the tubular film 40 from the roll R, the controller 600 controls the perforation of the tubular film 40. As is known in the art, when wrapping the load L, the controller 600 (partially) determines the length of the section of tubular film 40 based on the height of the load L.

[0035] The film opening assembly 300 includes suitable components that are configured to open the bottom portion of the section of tubular film 40, causing it to form a generally rectangular perimeter in preparation for receiving by the receiving and wrapping assembly 400. More specifically, and as is known in the art, the film opening assembly 300 includes four suction boxes and four corresponding holding devices (not labeled) that are capable of moving laterally inwards and outwards relative to the section of tubular film 40 in the X and Y directions and generally parallel to the X–Y plane. To open the bottom portion of the section of tubular film 40, the suction boxes move laterally inwards in the X and Y directions such that they are positioned adjacent to the outer surface of the bottom portion of the section of tubular film 40. A vacuum is generated to pull the bottom portion of the section of tubular film 40 onto the suction boxes, thereby partially opening the bottom portion. Then, the holding devices clamp the section of tubular film, and the suction boxes and the holding devices move laterally outwards in the X and Y directions and generally parallel to the X–Y plane to open the bottom portion of the section of tubular film 40 in preparation for receiving. At this time, the perimeter of the bottom portion of the section of tubular film 40 forms a generally rectangular shape in preparation for receiving. This is merely one example of the film opening assembly 300, and other embodiments of the film opening assembly 300 may include any other suitable components.

[0036] The stowage and wrap assembly 400 includes a wrapping carriage (not shown for clarity); a wrapping carriage actuator 410; a first stowage device 420, a second stowage device 430, a third stowage device 440, and a fourth stowage device 450; and a first set of stowage device actuators 420a and a second set of stowage device actuators 440a. The wrapping carriage includes a suitable frame and is vertically movable in the Z direction between an upper position and a lower position relative to the machine frame 100. The wrapping carriage actuator 410 is operably connected to the wrapping carriage to move the wrapping carriage between its upper position and lower position, and the wrapping carriage actuator may include any suitable actuator (such as an electric motor or a hydraulic motor).

[0037] Figure 3 , Figure 8 ,as well as Figure 10 4. The first retracting device 420 is shown, which includes: a first support member 421; a first retracting finger 422, which extends generally vertically in the Z direction from one end of the first support member 421; a freely rotatable first guide roller 422a, which is mounted to the first retracting finger 422; a first track 423, which is supported by the first support member 421; a first bracket 424, which is mounted to the first track 423 and is configured to move along the first track 423 in an original position (spaced from the first guide roller 422a) Figure 3 ) and the retracted position adjacent to the first guide roller 422a ( Figure 8 and Figure 10 ); a first drive roller 425, which is supported by the first bracket 424; a first roller actuator 426, which is supported by the first bracket 424 and is operably connected to the first drive roller 425 to rotate the first drive roller 425 in opposite retracting rotation directions and releasing rotation directions; and a first bracket actuator 427, which is operably connected to the bracket 424 to move the bracket 424 between its original position and the retracted position.

[0038] The second receiving device 430 is similar to the first receiving device 420 and thus not shown separately. The second receiving device includes: a second support member 431; a second receiving finger 432 that extends generally vertically from one end of the second support member 431; a freely rotatable second guide roller 432a that is mounted to the second receiving finger 432; a second rail 433 that is supported by the second support member 431; a second carriage 434 that is mounted to the second rail 433 and is configured to move along the second rail 433 between an original position spaced apart from the second guide roller 432a and a receiving position adjacent to the second guide roller 432a; a second drive roller 435 that is supported by the second carriage 434; a second roller actuator 436 that is supported by the second carriage 434 and is operatively connected to the second drive roller 435 to rotate the second drive roller 435 in opposite receiving and releasing rotational directions; and a second carriage actuator 437 that is operatively connected to the carriage 434 to move the carriage 434 between its original position and the receiving position.

[0039] The third receiving device 440 is similar to the first receiving device 420 and thus not shown separately. The third receiving device includes: a third support member 441; a third receiving finger 442 that extends generally vertically from one end of the third support member 441; a freely rotatable third guide roller 442a that is mounted to the third receiving finger 442; a third rail 443 that is supported by the third support member 441; a third carriage 444 that is mounted to the third rail 443 and is configured to move along the third rail 443 between an original position spaced apart from the third guide roller 442a and a receiving position adjacent to the third guide roller 442a; a third drive roller 445 that is supported by the third carriage 444; a third roller actuator 446 that is supported by the third carriage 444 and is operatively connected to the third drive roller 445 to rotate the third drive roller 445 in opposite receiving and releasing rotational directions; and a third carriage actuator 447 that is operatively connected to the carriage 444 to move the carriage 444 between its original position and the receiving position.

[0040] The fourth receiving device 450 is similar to the first receiving device 420 and thus is not shown separately. The fourth receiving device includes: a fourth support member 451; a fourth receiving finger 452 that extends generally vertically from one end of the fourth support member 451; a freely rotatable fourth guide roller 452a that is mounted to the fourth receiving finger 452; a fourth rail 453 that is supported by the fourth support member 451; a fourth carriage 454 that is mounted to the fourth rail 453 and is configured to move along the fourth rail 453 between an original position spaced apart from the fourth guide roller 452a and a receiving position adjacent to the fourth guide roller 452a; a fourth drive roller 455 that is supported by the fourth carriage 454; a fourth roller actuator 456 that is supported by the fourth carriage 454 and is operatively connected to the fourth drive roller 455 to rotate the fourth drive roller 455 in opposite receiving and dispensing rotational directions; and a fourth carriage actuator 457 that is operatively connected to the carriage 454 to move the carriage 454 between its original position and the receiving position.

[0041] The first receiving device 420, the second receiving device 430, the third receiving device 440, and the fourth receiving device 450 are mounted to the frame of the package carriage in a generally rectangular arrangement. A first set of receiving device actuators 420a are operatively connected to the first receiving device 420 and the second receiving device 430 to move the first receiving device 420 and the second receiving device 430 laterally inwards and outwards relative to the package carriage (and the load L and the tubular film 40 section) in the X and Y directions and generally parallel to the X-Y plane. A second set of receiving device actuators 440a are operatively connected to the third receiving device 440 and the fourth receiving device 450 to move the third receiving device 440 and the fourth receiving device 450 laterally inwards and outwards relative to the package carriage (and the load L and the tubular film 40 section) in the X and Y directions and generally parallel to the X-Y plane.

[0042] The first set of retracting device actuators 420a includes a first X actuator and a first Y actuator that are independently controlled from each other. The first X actuator is operatively connected to the first retracting device 420 and the second retracting device 430 and is configured to move the first retracting device 420 and the second retracting device 430 relative to the package carrier in the X direction. The first Y actuator is operatively connected to the first retracting device 420 and the second retracting device 430 and is configured to move the first retracting device 420 and the second retracting device 430 relative to the package carrier in the Y direction. In this exemplary embodiment, the first X actuator and the first Y actuator include electric motors controlled by separate variable frequency drives, but in other embodiments the actuators can be any suitable actuators (such as hydraulic motors controlled by proportional solenoid valves). In this exemplary embodiment, the first X actuator moves the first retracting device and the second retracting device simultaneously and at the same rate in the X direction toward and away from the load. Similarly, the first Y actuator moves the first retracting device and the second retracting device simultaneously and at the same rate in the Y direction toward and away from the load.

[0043] The second set of retracting device actuators 440a includes a second X actuator and a second Y actuator that are independently controlled from each other. The second X actuator is operatively connected to the third retracting device 440 and the fourth retracting device 450 and is configured to move the third retracting device 440 and the fourth retracting device 450 relative to the package carrier in the X direction. The second Y actuator is operatively connected to the third retracting device 440 and the fourth retracting device 450 and is configured to move the third retracting device 440 and the fourth retracting device 450 relative to the package carrier in the Y direction. In this exemplary embodiment, the second X actuator and the second Y actuator include electric motors controlled by separate variable frequency drives, but in other embodiments the actuators can be any suitable actuators (such as hydraulic motors controlled by proportional solenoid valves). In this exemplary embodiment, the second X actuator moves the third retracting device and the fourth retracting device simultaneously and at the same rate in the X direction toward and away from the load. Similarly, the second Y actuator moves the third retracting device and the fourth retracting device simultaneously and at the same rate in the Y direction toward and away from the load.

[0044] In other embodiments, the stretch hood machine includes a separate set of one or more retracting device actuators for each individual retracting device. In some of these embodiments, each set of retracting device actuators includes independently controlled X and Y actuators similar to those described above.

[0045] The operator interface 500 is configured to receive input from an operator and, in some embodiments, is configured to output information to the operator. The operator interface includes one or more input devices configured to receive input from the operator. In various embodiments, the one or more input devices include one or more buttons (such as hard keys or soft keys), one or more switches, and / or a touch panel. In various embodiments, the operator interface 500 includes a display device configured to display information to the operator, such as information about the pallet load, the status of the wrapping operation, or the settings of the stretch wrapper 10. The operator interface may include other output devices in lieu of or in addition to the display device, such as one or more speakers and / or one or more lights. In some embodiments, the operator interface 500 is formed as part of the stretch wrapper 10 and is mounted, for example, to the machine frame 100. In other embodiments, the operator interface is remote from the stretch wrapper 10.

[0046] The controller 600 includes a processing device communicatively connected to a memory device. The processing device may include any suitable processing device, such as but not limited to a general-purpose processor, a dedicated processor, a digital signal processor, one or more microprocessors, one or more microprocessors associated with a digital signal processor core, one or more application-specific integrated circuits, one or more field-programmable gate array circuits, one or more integrated circuits, and / or a state machine. The memory device may include any suitable memory device, such as but not limited to read-only memory, random access memory, one or more digital registers, cache memory, one or more semiconductor memory devices, such as magnetic media like integrated hard drives and / or removable memory, magneto-optical media, and / or optical media. The memory device stores instructions executable by the processing device to control the operation of the stretch wrapper 10.

[0047] The controller 600 is communicatively and operably connected to the film supply assembly 200 and any perforators included therein (e.g., perforator 220, as further described below); the film opening assembly 300; the parcel carriage actuator 410; the first set of retraction device actuators 420a and the second set of retraction device actuators 440a; and the first set of roller actuators 426, the second set of roller actuators 436, the third set of roller actuators 446, and the fourth set of roller actuators 456; the first carriage actuator 427, the second carriage actuator 437, the third carriage actuator 447, and the fourth carriage actuator 457. The controller 600 is communicatively connected to the operator interface 500 to: (1) receive signals from the operator interface 500 representative of the input received by the operator interface 500; and (2) send signals to the operator interface 500 to cause the operator interface 500 to output (such as display) information.

[0048] At the start of the wrapping process, a tubular film section is produced. In this exemplary embodiment, the controller 600 controls the film supply assembly 200 to pull the tubular film 40 from the film roll R, optionally perforate the tubular film 40, and cut the film to a desired length (which depends on the height of the load) to form a section of the tubular film 40. Then the bottom portion of the tubular film section is opened. In this exemplary embodiment, the controller 600 controls the film opening assembly 300 (and more specifically, the suction box and the holding device) to open the bottom portion of the tubular film 40 section so that the shape of its perimeter is generally rectangular, as explained above.

[0049] Then the receiving devices are moved to their insertion positions. In this exemplary embodiment, the controller 600 controls the first set of receiving device actuators 420a and the second set of receiving device actuators 440a to move the respective receiving devices 420, 430, 440, and 450 laterally and inwardly relative to the tubular film 40 section (in the X and Y directions and generally parallel to the X-Y plane) to the respective insertion positions of the receiving devices, at which insertion positions the receiving devices form an insertion configuration. Figure 4 and Figure 5 The receiving devices 420, 430, 440, and 450 are shown in their insertion positions. The insertion positions are preset (e.g., by an operator) based on a number of factors, including the size of the film (e.g., its unstretched perimeter). At this time, as Figure 3 shown for the receiving device 420, the first brackets 424, the second brackets 434, the third brackets 444, and the fourth brackets 454 of the first receiving device 420, the second receiving device 430, the third receiving device 440, and the fourth receiving device 450 are in their respective original positions. Then the wrapping carriage is raised so that the receiving fingers of the receiving devices are received in the open bottom portion of the tubular film section. In this exemplary embodiment, the controller 600 controls the wrapping carriage actuator 410 to raise the wrapping carriage so that the receiving fingers 422, 432, 442, and 452 of the respective receiving devices 420, 430, 440, and 450 are received in the open bottom portion of the tubular film 40 section.

[0050] Then the receiving devices are moved to their receiving positions, and the receiving devices receive the tubular film sections onto the receiving fingers. In this exemplary embodiment, the controller 600 controls the first set of receiving device actuators 420a and the second set of receiving device actuators 440a to laterally move the respective receiving devices 420, 430, 440, and 450 relative to the tubular film 40 sections (in the X and Y directions and generally parallel to the X–Y plane) laterally in and out to their respective receiving positions, at which the receiving devices form a receiving configuration to prepare for receiving the tubular film 40 sections. Then, the controller 600 controls the first carriage actuator 427, the second carriage actuator 437, the third carriage actuator 447, and the fourth carriage actuator 457 to move the respective carriages 424, 434, 444, and 454 from their respective original positions to their respective receiving positions, which causes the drive wheels 425, 435, 445, and 455 of the receiving devices 420, 430, 440, and 450 to contact the inner surface F IS of the tubular film 40 section, and forces the outer surface F OS of the tubular film 40 section against the respective guide wheels 422a, 432a, 442a, and 452a. Figures 6 to 8 Shows the receiving devices in their receiving positions after the carriages of the receiving devices 420, 430, 440, and 450 have been moved to their respective receiving positions. In some embodiments, when the receiving devices are moved to their receiving positions, the carriages are moved to their receiving positions. Then, the controller 600 controls the first roller actuator 426, the second roller actuator 436, the third roller actuator 446, and the fourth roller actuator 456 to drive the first drive roller 425, the second drive roller 435, the third drive roller 445, and the fourth drive roller 455 in the receiving rotation direction, thereby receiving the tubular film 40 sections onto the receiving fingers 422, 432, 442, and 452. Figure 9 and Figure 10 Shows the receiving devices 420, 430, 440, and 450 after receiving.

[0051] The receiving devices then begin to move toward their respective wrapping positions to form a wrapping configuration. In this exemplary embodiment, the controller 600 controls the first set of receiving device actuators 420a and the second set of receiving device actuators 440a to move the respective receiving devices 420, 430, 440, and 450 from their respective receiving positions to their respective wrapping positions, thereby stretching the tubular film sections. Here, the wrapping positions of the respective receiving devices are laterally positioned in and out relative to the receiving positions (in the X and Y directions and generally parallel to the X-Y plane). Additionally, the receiving devices each follow a 45-degree path in the X-Y plane when moving from their respective receiving positions to their respective wrapping positions (although in other embodiments, the movement path and resulting angle may be different).

[0052] After the receiving device reaches the package configuration, the package carrier descends relative to the load (in the Figure 1 Z direction shown). During this descent, the motor drives the drive roller of the receiving device to pay out the remainder of the film from the receiving fingers at the pay-out speed in the pay-out rotation direction. When this occurs, the film attempts to return to its unstretched size and shape and laterally contracts onto the load, which integrates the load and / or secures the load to the pallet. This completes the packaging process, and the conveyor transports the load out of the stretch hood machine.

[0053] Figure 12A and Figure 12B An exemplary embodiment using a perforator 220 is shown to form perforations in a central portion of a section of tubular film 40 to package an article including a pallet P and a load L. In this exemplary embodiment, the tubular film roll R used is shown in Figure 11 . As shown, the tubular film 40 provided on the roll R has a tubular form that has an opening 41 at the free end of the tubular film 40, which provides access to the interior of the tubular film 40. The tubular film 40 unfolds from the roll as a flat sheet that has a width extending from an edge along a first side 42 of the sheet to an edge along a second side 45 of the sheet. Along each side of the sheet of the tubular film 40, a portion of the film is folded to form gussets. For example, as Figure 11 shown, a first gusset 43 is formed along the first side 42 and extends inwardly toward the center of the tubular film sheet to a fold edge 44. Similarly, a second gusset 46 is formed along the second side 45 and extends inwardly toward the center of the sheet to a fold edge 47. When the tubular film 40 is opened to provide an interior space for the load, the fold edges 44, 47 of the gussets 43, 46 move away from each other such that the interior of the tubular film 40 can expand.

[0054] When the tubular film 40 is flat, such as when the tubular film is removed from the film roll R and before the tubular film is opened, the area of the sheet between the first side 42 of the sheet and the fold edge 44 of the first gusset 43 is stacked in four layers. Similarly, the area of the sheet between the second side 45 of the sheet and the fold edge 47 of the second gusset 46 is also stacked in four layers. On the other hand, each of the first gusset 43 and the second gusset 46 has a width less than half the width of the film roll R, such that there is a gap between the fold edge 44 of the first gusset 43 and the fold edge 47 of the second gusset 46. In the gap area between the fold edge 44 of the first gusset 43 and the fold edge 47 of the second gusset 46, the flat tubular film 40 has two layers.

[0055] Figure 12A andFigure 12B Shows the perforator 220 associated with the film supply assembly 200 of the stretch hooding machine 10, as described in detail above. A roller 210, which is part of the film supply assembly 200, guides the tubular film 40 to the perforator 220, where the tubular film 40 is perforated to form holes through the layers of the tubular film. The stretch hooding machine may also include additional rollers to guide the tubular film 40 to other parts of the machine, such as a film opening assembly. Figure 12A and Figure 12B The illustrated perforator 220 includes a perforating roller 230 and a receiving roller 240 that are configured to receive the tubular film in a flat configuration and form holes through a portion of the tubular film.

[0056] The perforating roller 230 extends from a first side 42 of the tubular film to a second side 45 of the tubular film. The receiving roller 240 similarly extends from the first side 42 of the tubular film to the second side 45 of the tubular film. The perforating roller 230 includes perforating pins 232 that are positioned in rows along the circumference of the perforating roller 230. In the illustrated embodiment, there are two rows of perforating pins 232, the perforating pins are evenly spaced along these rows, and the two rows are equidistantly spaced around the circumference of the perforating roller 230. In other embodiments, there may be more than two rows of perforating pins. Further, in some embodiments, the rows of perforating pins may be non-uniformly spaced around the circumference of the perforating roller. Additionally, the spacing of the perforating pins along the rows may be non-uniform. For example, in some embodiments, gaps may be provided in the perforating pins along the rows to, for example, avoid the folded edges of gussets or the corners of an inflated tubular film.

[0057] Figure 12A Shows the perforator 220 in a disengaged state such that the tubular film 40 can move through the perforator 220 when a new section of the tubular film is pulled from the tubular film roll. Similarly, if the controller of the stretch hooding machine does not enable the perforator 220, the tubular film can be moved through the perforator without perforating the tubular film 40. Figure 12B Shows the perforator 220 in an engaged state to form perforations in the tubular film 40. In the illustrated embodiment, the perforating roller 230 can be laterally moved to reduce the distance between the perforating roller 230 and the receiving roller 240. When the perforating roller 230 is in the engaged position, the perforating pins 232 are configured to pierce through the layers of the tubular film 40 and press into the surface of the receiving roller 240. As the perforating roller 230 rotates about an axis, the perforating pins 232 pierce through the layers of the tubular film 40, and as the perforating pins 232 press into the surface of the receiving roller 240, holes are formed.

[0058] As described above, the region between the first side 42 of the sheet of the tubular membrane 40 and the folded edge 44 of the first gusset 43 is stacked in four layers, and the region between the second side 45 of the sheet and the folded edge 47 of the second gusset 46 is also stacked in four layers. In these regions, perforations will be formed through all four layers. In the two-layer central section of the tubular membrane, perforations will be formed through the two layers.

[0059] In the illustrated embodiment, as the perforating roller 230 and the receiving roller 240 rotate, the perforator 220 passes through the tubular membrane 40, thereby causing perforations to be formed each time the perforating pins 232 engage the receiving roller 240. More specifically, a perforation is formed each time the perforating roller 230 completes a half-turn rotation while the perforator 220 is in the engaged state. In other embodiments where the perforating roller has more than two rows of perforating pins, perforations can be formed incrementally based on the number of rows of perforating pins.

[0060] Figure 13 An embodiment of a perforator for a stretch hood machine is shown, which provides multiple perforating rollers to form perforations of various configurations. In the illustrated embodiment, the perforator 1220 includes a first perforating roller 1230, a second perforating roller 1240, and a third perforating roller 1250. Similar to Figure 13 the illustrated perforating roller 230, each of the perforating rollers 1230, 1240, and 1250 extends from the first side 42 of the tubular membrane 40 to the second side 45 of the tubular membrane 40.

[0061] Each of the perforating rollers 1230, 1240, and 1250 includes various perforating pins of different configurations and shapes. The first perforating roller 1230 includes square perforating pins 1234, which have a rectangular prism shape and are configured to form square orifices in the tubular membrane. The second perforating roller 1240 includes small perforating pins 1244, which have a small cylindrical shape and are configured to form small circular holes in the tubular membrane. The third perforating roller 1250 includes large perforating pins 1254, which also have a cylindrical shape and are configured to form larger circular holes in the tubular membrane. The larger perforating pins 1254 of the third perforating roller 1250 have a diameter larger than the diameter of the small perforating pins 1244 of the second perforating roller 1240. In the illustrated embodiment, each of the perforating rollers 1230, 1240, 1250 includes two rows of perforating pins, which are equally spaced around the circumference of the perforating roller, thereby causing perforations to be formed each time the roller is engaged during a half-turn rotation.

[0062] Because there are various perforating rollers 1230, 1240, and 1250 in the perforator 1220, the controller of the stretch hood machine can selectively enable the first perforating roller 1230, the second perforating roller 1240, or the third perforating roller 1250 to form perforations. When a specific perforating roller is enabled, that perforating roller can form perforations of a corresponding shape in the tubular film, while the other perforating rollers remain disabled. The other two perforating rollers will remain disengaged. In the illustrated configuration, the perforating roller 1240 is engaged, while the perforating rollers 1230 and 1250 are disengaged.

[0063] It should be understood that Figure 13 the illustrated embodiment is only one possible embodiment of a perforator having selectable perforating rollers. In other embodiments, the perforating rollers can have perforating pins of several other shapes. Additionally, the perforator can have any number of perforating rollers, with each perforating roller having a different configuration of perforating pin shape, size, and number. For example, in some embodiments, there can be multiple perforating rollers that can have perforating pins of the same shape and size, but each perforating roller can have a different number of perforating pins. In this example, the user will be able to control the perforator and thus the number of perforations produced by controlling which specific perforating roller is engaged and which specific perforating roller is disengaged.

[0064] Figure 14A and Figure 14B Another embodiment of a perforator of a stretch hood machine is shown, which allows perforations to be formed in a tubular film. Figure 14A An embodiment of the perforator 2220 is shown, which is similar to Figure 12A the perforator shown in FIG. 12, except that the perforator 2220 includes a perforating track 2230 and a receiving track 2240 instead of including perforating rollers and receiving rollers. Figure 14A The perforator 2220 is shown in a disengaged state, while Figure 14B the perforator 2220 is shown in an engaged state.

[0065] In the disengaged state, when a new section of the tubular film is pulled from the tubular film roll, the tubular film 40 can move through the perforator 2220. Similarly, if the perforator 2220 is not enabled to engage, the tubular film 40 can move through the perforator with perforations. Figure 14BThe piercer 2220 is shown in an engaged state to form perforations in the tubular film 40. In the illustrated embodiment, the piercing track 2230 can be laterally moved to reduce the distance between the piercing track 2230 and the receiving track 2240. When the piercing track 2230 is in the engaged position, the piercing pin 2232 is configured to pierce through the layers of the tubular film 40 and press into the surface of the receiving track 2240. To form another set of perforations within the same section of the tubular film, the piercing track 2230 can be engaged and disengaged several times as the section of the tubular film is pulled through the piercer 2220.

[0066] In other embodiments, the piercer can include more than one piercing track and one receiving track, similar to Figure 13 the piercer shown. Further, in some embodiments, several piercing tracks can be configured to perform piercing simultaneously to form several rows of perforations at once. Additionally, in some embodiments, the piercing tracks can include piercing pins that differ in number, shape, and size.

[0067] Figure 15 Another embodiment of a piercer 3220 of a stretch hooder is shown that allows for the formation of perforations through a tubular film. The piercer 3220 includes a first track 3230 and a receiving track 3240. The first track 3230 includes a piercing assembly 3234 that traverses the length of the first track 3230 laterally based on the specific location where the perforations are to be formed. The piercing assembly 3234 includes piercing pins that can extend to pierce through the tubular film 40 and press into the receiving track 3240 to form perforations. To form multiple perforations, the piercing assembly 3234 can traverse the first track 3230 along the same axis to several points, thereby forming perforations at each point. The controller of the stretch hooder can operate the piercing assembly 3234 to perforate the tubular film at a uniform distance between points or at a non-uniform distance between points. Further, the controller can operate the piercing assembly to select to form a specific number of perforations. As in the above embodiments, the piercer 3220 can remain in a disengaged state such that the tubular film can pass through the piercer 3220 without perforations being formed in the tubular film 40. In other embodiments, the piercer can have several piercing assemblies. Additionally, the piercer can include more than one track, where each of the tracks can include at least one piercing assembly.

[0068] Figures 16 to 18 An exemplary embodiment of a perforated tubular film for use in a stretch hooder is shown. Figure 16An embodiment of a perforated tubular membrane 1640 is shown, which includes multiple rows of perforations 1652 spanning from a first side 1642 of the tubular membrane 1640 to a second side 1645 of the tubular membrane. Similar to the tubular membrane 40, the region of the sheet between the first side 1642 of the sheet and the folded edge 1644 of the first gusset 1643 is stacked in four layers, and the region of the sheet between the second side 1645 of the sheet and the folded edge 1647 of the second gusset 1646 is also stacked in four layers. In these regions, the perforations 1652 are formed through all four layers. In the two-layer central section of the tubular membrane, the perforations 1652 are formed through only two layers. In this embodiment, the perforations 1652 are configured such that when the perforated tubular membrane 1640 is wrapped around the load on the tray (as Figure 19 shown), the tubular membrane will be perforated on all four sides of the load. In other embodiments, the perforations can be non-uniformly spaced in both the vertical and horizontal directions. Additionally, the perforations can be of other shapes or sizes. Further, other embodiments can include more or fewer rows of perforations.

[0069] Figure 17 An exemplary embodiment of a perforated tubular membrane for use in a stretch hood machine is shown. Figure 17 A perforated tubular membrane 1740 including multiple rows of perforations 1752 is shown. Similar to the tubular membrane 40, the region of the sheet between the first side 1742 of the sheet and the folded edge 1744 of the first gusset 1743 is stacked in four layers, and the region of the sheet between the second side 1745 of the sheet and the folded edge 1747 of the second gusset 1746 is also stacked in four layers. The perforations 1752 are vertically spaced in the tubular membrane section between the folded edge 1744 of the first gusset 1743 and the folded edge 1747 of the second gusset 1746. Since the perforations 1752 are formed only between the folded edges 1744, 1747 of the gussets 1743, 1746, the perforations 1752 pass through only two layers of the membrane. Thus, in this embodiment, when the perforated tubular membrane 1740 is wrapped around the load on the tray, the perforations 1752 will be on two sides of the load. In other embodiments, the perforations can be non-uniformly spaced in both the vertical and horizontal directions. Additionally, the perforations can be of other shapes or sizes. Further, other embodiments can include more or fewer rows of perforations. Figure 18 Another exemplary embodiment of a perforated tubular membrane is shown, which includes perforations 1852 having a diameter greater than Figure 17 the diameter of the perforations 1752 of the embodiment shown.

[0070] Figure 19Shows a section of perforated tubular film 1940 that has been wrapped around a load L on a tray P by a stretch hood system. For clarity, Figure 19 the stretch hood machine is not shown in Figure 19 . The tubular film 1940 includes perforations 1952 that can help control moisture or other environmental conditions inside the tubular film.

[0071] Further, in some embodiments, the perforator includes other cutting devices (including laser cutters or water jets).

[0072] Although the above embodiments are described in the context of a tubular film from a single roll of film, in some embodiments, the stretch hood machine can include a plurality of rolls of film. For example, the stretch hood machine can hold rolls of film having different widths, strengths, or other characteristics. In some embodiments that include multiple rolls of film, the stretch hood machine can be configured to direct film from each roll of film to the same perforator or multiple perforators. In other embodiments, the stretch hood machine can include a separate perforator associated with each of the rolls of film. For example, a first perforator can be configured to perforate film from a first roll, and a second perforator can be configured to perforate film from a second roll.

[0073] The present disclosure also provides a method for performing a series of wrapping operations to wrap an article with and without forming perforations in a tubular film. For example, in a series of wrapping operations, a first wrapping operation includes: receiving a first article in a stretch hood machine; pulling a tubular film from a roll of film; perforating the tubular film after the tubular film has been pulled from the roll of film so as to form perforations disposed along the length of the tubular film; advancing the tubular film onto the advancing fingers of a plurality of advancing devices; lowering the advancing devices around the article to wrap the article inside the tubular film; and removing the wrapped first article from the stretch hood machine.

[0074] A second wrapping operation in this series of wrapping operations includes: receiving a second article in the stretch hood machine; pulling additional tubular film from the roll of film; positioning the additional tubular film on the advancing devices without perforating the additional tubular film; advancing the additional tubular film onto the advancing fingers of the advancing devices; lowering the advancing devices around the article to wrap the second article inside the additional tubular film; and removing the wrapped second article from the stretch hood machine.

[0075] Forming the perforations in the first wrapping operation can be performed using any one of the described perforators according to any one of the methods described above.

[0076] Accordingly, in various embodiments, the present disclosure provides a method of operating a stretch hooder to wrap an article with a tubular film. The method includes pulling a section of the tubular film from a film roll and perforating the tubular film after the tubular film has been pulled from the film roll so as to form perforations disposed along the length of the tubular film. The method further includes advancing the tubular film onto the advancing fingers of a plurality of advancing devices and lowering the advancing devices around the article to wrap the article within the interior of the tubular film.

[0077] In various such embodiments of the method, the tubular film is perforated as the tubular film travels from the film roll to the advancing fingers.

[0078] In various such embodiments of the method, the perforations are arranged to permit airflow through the film.

[0079] In various such embodiments of the method, the perforations are arranged in columns extending along the length of the tubular film.

[0080] In various such embodiments of the method, the perforations in the tubular film are arranged to be spaced apart from the corners of the article when the article is wrapped within the interior of the tubular film.

[0081] In various such embodiments of the method, the method further includes using a controller of the stretch hooder to select the number of perforations formed along the length of the tubular film.

[0082] In various such embodiments of the method, the method further includes using a controller of the stretch hooder to select a first set of perforating pins for perforating the tubular film.

[0083] In various such embodiments of the method, the stretch hooder includes a second set of perforating pins.

[0084] In various such embodiments of the method, the first set of perforating pins is different in size from the second set of perforating pins.

[0085] In various such embodiments of the method, the first set of perforating pins is different in shape from the second set of perforating pins.

[0086] In various such embodiments of the method, the method further includes: removing a first article from the stretch hooder, receiving a second article in the stretch hooder, pulling additional tubular film from the film roll, and positioning the additional tubular film on the advancing devices without perforating the additional tubular film. The method further includes advancing the additional tubular film onto the advancing fingers of the advancing devices; and lowering the advancing devices around the article to wrap the second article within the interior of the additional tubular film.

[0087] In various such embodiments of the method, the tubular film pulled from the roll is an unperforated film.

[0088] In various such embodiments of the method, the method further comprises: removing a first article from the stretch hooder, placing a second article in the stretch hooder, pulling additional unperforated tubular film 40 from a film roll, positioning the additional unperforated tubular film on a pick-up device, picking up the additional unperforated tubular film onto pick-up fingers of the pick-up device, and lowering the pick-up device around the article to enclose the second article within the interior of the additional unperforated tubular film.

[0089] In various embodiments, the present disclosure provides a stretch hooder. The stretch hooder includes a machine frame, a wrapping carriage, a plurality of pick-up devices supported by the wrapping carriage, a film supply assembly, and a perforator. The wrapping carriage is movable relative to the machine frame between an upper position and a lower position. The pick-up devices are configured to pick up a section of tubular film, stretch the section of tubular film, and pay out the section of tubular film. The film supply assembly is configured to pull tubular film from a film roll, cut the tubular film from the roll to form the section of tubular film, and guide the section of tubular film to the pick-up devices. The perforator is configured to form perforations disposed along the length of the tubular film after pulling the tubular film from the roll and before the pick-up devices pick up the section of tubular film.

[0090] In various such embodiments of the stretch hooder, the stretch hooder further includes a controller configured to selectively enable the perforator.

[0091] In various such embodiments of the stretch hooder, the perforator includes a first set of perforation pins and a second set of perforation pins.

[0092] In various such embodiments of the stretch hooder, the stretch hooder further includes a controller configured to selectively enable the first set of perforation pins or the second set of perforation pins.

[0093] In various such embodiments of the stretch hooder, the first set of perforation pins is different in size from the second set of perforation pins.

[0094] In various such embodiments of the stretch hooder, the first set of perforation pins is different in shape from the second set of perforation pins.

[0095] In various such embodiments of the stretch hooder, the stretch hooder further includes a controller configured to determine the number of perforations formed in the tubular film.

[0096] Various different changes and modifications to the above-described embodiments of the present disclosure will be apparent to those skilled in the art. These changes and modifications can be made without departing from the spirit and scope of the subject matter and without diminishing its intended advantages. Not all of the depicted branches described in the present disclosure are required, and some implementations may include additional, different, or fewer branches compared to those explicitly described in the present disclosure. The arrangement and type of components; the shape, size, and material of the components; and the additional and connection manners of the branches can be varied without departing from the spirit or scope of the claims set forth herein. Additionally, unless otherwise stated, any directions mentioned herein reflect the orientation of the branches shown in the corresponding drawings and do not limit the scope of the present disclosure. This specification is intended to be considered as a whole and interpreted in accordance with the principles of the present invention as taught herein and understood by those of ordinary skill in the art.

Claims

1. A method of operating a stretch wrapper machine to wrap an article with a tubular film, the method comprising: Pull a tubular film from a film roll; Perforate the tubular film after the tubular film has been pulled from the film roll so as to form perforations arranged along the length of the tubular film; Feed the tubular film onto the feeding fingers of a plurality of feeding devices; And Lower the feeding devices around the article to wrap the article inside the tubular film.

2. The method according to claim 1, wherein, Perforate the tubular film as the tubular film travels from the film roll to the feeding fingers.

3. The method according to claim 1, wherein, The perforations are arranged to allow air flow through the film.

4. The method according to claim 1, wherein, The perforations are arranged in columns extending along the length of the tubular film.

5. The method according to claim 1, wherein, The perforations in the tubular film are arranged to be spaced apart from the corners of the article when the article is wrapped inside the tubular film.

6. The method according to claim 1, further comprising: Use the controller of the stretch hooding machine to select the number of the perforations formed along the length of the tubular film.

7. The method according to claim 1, further comprising: Use the controller of the stretch hooding machine to select a first set of perforation pins for perforating the tubular film.

8. The method according to claim 7, wherein, The stretch hooding machine includes a second set of perforation pins.

9. The method according to claim 8, wherein, The first set of perforation pins is different in size from the second set of perforation pins.

10. The method according to claim 8, wherein, The first set of perforation pins is different in shape from the second set of perforation pins.

11. The method according to claim 1, further comprising: Remove the first article from the stretch hooding machine; Receive a second article in the stretch hooding machine; Pull an additional tubular film from the film roll; Position the additional tubular film on the feeding device without perforating the additional tubular film; Feed the additional tubular film onto the feeding fingers of the feeding device; And Lower the feeding device around the article to wrap the second article inside the additional tubular film.

12. The method according to claim 1, wherein, The tubular film pulled from the roll is an unperforated film.

13. The method according to claim 12, further comprising: Remove the first article from the stretch hooding machine; Place a second article in the stretch hooding machine; Pull an additional unperforated tubular film from the film roll; Position the additional unperforated tubular film on the feeding device; Feed the additional unperforated tubular film onto the feeding fingers of the feeding device; And Lower the feeding device around the article to wrap the second article inside the additional unperforated tubular film.

14. A stretching and sleeving machine, the stretching and sleeving machine comprising: Machine frame; A wrapping carriage that is movable relative to the machine frame between an upper position and a lower position; A plurality of feeding devices supported by the wrapping carriage and configured to feed a section of tubular film, stretch the section of tubular film, and pay out the section of tubular film; A film supply assembly configured to pull a tubular film from a film roll, cut the tubular film 40 from the roll to form the section of tubular film, and guide the section of tubular film to the feeding device; And A perforator configured to form perforations arranged along the length of the tubular film after the tubular film is pulled from the roll and before the feeding device feeds the section of tubular film.

15. The stretching and sleeving machine according to claim 14, further comprising: A controller configured to selectively enable the perforator.

16. The stretching and sleeving machine according to claim 14, wherein The perforator includes a first set of perforation pins and a second set of perforation pins.

17. The stretching and sleeving machine according to claim 16, further comprising: A controller configured to selectively enable the first set of perforating pins or the second set of perforating pins.

18. The stretching and sleeving machine according to claim 17, wherein The first set of perforating pins is different in size from the second set of perforating pins.

19. The stretching and sleeving machine according to claim 17, wherein The first set of perforating pins is different in shape from the second set of perforating pins.

20. The stretching and sleeving machine according to claim 14, further comprising: A controller configured to determine the number of perforations formed in the tubular film.

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