Modular wrapping machine

Abstract

A wrapping machine features a modular configuration, allowing for the replacement of one or more modules after delivery and simplifying the assembly of multiple machine configurations using a relatively small number of modules.

Description

[0001] Modular wrapping machine DESCRIPTION

[0002] TECHNICAL FIELD

[0003] The present invention relates to a modular packaging machine for packaging a product using reel-fed packaging material.

[0004] BACKGROUND ART

[0005] There is a growing need to achieve the benefits of modular production, enabling faster manufacturing and delivery while reducing production costs for packaging machines of various models.

[0006] OBJECTIVES AND BRIEF SUMMARY OF THE INVENTION

[0007] The objective of the present invention is achieved through a machine defining a process path for a product, preferably but not exclusively stacked as a horizontal or vertical stack of tissues or a matrix of adjacent rolls of paper, e.g., kitchen or toilet paper, in a parallelepiped shape to be packaged, comprising:

[0008] - In one or more modules: a product feeding unit equipped with at least one conveyor with a first servomotor, an introduction unit receiving the product from the conveyor, having a second servomotor, for preparing the product, e.g., compression or alignment, a reel-holder unit with a third servomotor to handle a reel of sheet material, and a frame.

[0009] - a heated belt module for heating purposes to activate an adhesive applied to the sheet material wrapped around the product or to seal the sheet material wrapped around the product forming a package and to fix opposing lateral flaps of the package through dedicated folding guides interacting with the flaps and is equipped with a fourth servomotor for product movement and mountable preferably in a forward or rearward position relative to the process direction of the product along the process path.

[0010] Alternatively, placed between the introduction unit and the heated belt module:

[0011] - in one or more modules: a traction belt assembly located upstream of the heated belt module relative to the process direction and downstream of the conveyor, to wrap the sheet material around the product, the assembly having a first process parameter, such as a maximum processing speed or a maximum product size, and a fifth servomotor for wrapping the sheet material or moving the product; or

[0012] - In one or more modules: a wrapping assembly configured to wrap the reel- fed sheet material around the product and having a second process parameter, e.g., a second maximum processing speed or a second maximum product size, which is larger than the first process parameter, and a sixth servomotor for wrapping the sheet material or moving the product.

[0013] Wherein:

[0014] - the frame includes a first mounting interface, preferably holes, for mounting the traction belt assembly, and a second mounting interface, preferably additional holes, for mounting the wrapping assembly. The first and second interfaces are configured such that the traction belt assembly cannot be mounted on the second interface, and the wrapping assembly cannot be mounted on the first interface.

[0015] - at least two servomotors are synchronized to operate according to a phase diagram that links the motor positions to a virtual axis completing 360° each machine cycle, during which the product advances one step on the machine.

[0016] The frame is elongated in a first direction, and the product feeding module is elongated in a second direction, with the first and second directions being transverse, preferably perpendicular.

[0017] According to the present invention, a relatively small number of modules enables a wide variety of configurations, alongside cost and production speed advantages. Provisions are also included to prevent incorrect assembly during machine construction and / or synchronization errors between the servomotor machine axes.

[0018] Additionally, the machine includes at least two wrapping assemblies for sheet material wrapping around the product, which can be replaced to adjust a process parameter of the machine, such as the maximum processing speed (e.g., the number of packaged products per minute) or the product size to be wrapped, and so on.

[0019] In a preferred embodiment, the machine comprises an electrical panel with a plurality of electronic servo-controllers for the said servo-actuators and a control unit for data exchange with the plurality of servo- controllers, wherein at least one servocontroller of said plurality is pre-mounted in the panel, pre-connected for data exchange with the control unit, and disconnected from the servo -actuators during machine operation. For instance, such an additional servo -controller can be associated with the sixth servo-actuator but is disconnected and unused when the fifth servo-actuator is in use.

[0020] In this way, on board of the electrical panel more electronic servo-controllers than the servo-actuators required for one or more machine configurations are provided, so as to facilitate module replacement after the machine is delivered, as the servomotor is originally present on the machine post-assembly at the manufacturer and is already data-exchange connected to the control unit. In this way, a module replaced post-delivery is "plug-and-play," i.e., each servo-acuator of the additional or replacement module finds a pre-installed servo-controller in the electrical panel, already pre-connected to the machine's control unit. The control unit is implemented, by way of example, using a plurality of PLC elements.

[0021] In a preferred embodiment, the control unit is programmed to store at least one machine cycle function for each of the said servomotors and to receive at least one input data point representing the servomotors connected for data exchange and power supply with the electrical panel and to associate based on the input data each pre-stored machine cycle function with the corresponding servomotor, wherein at least one machine cycle function is pre-stored in the control unit and remains deactivated when the machine is in operation because the corresponding servomotor is not in use on the machine.

[0022] This further simplifies both the machine assembly process at the production workshop and the installation of a module purchased after the machine is already in operation since an additional or replacement module for one already installed on the machine finds the relevant control software pre-stored in the control unit. For example, such an additional machine cycle function can be associated with the sixth servomotor and remains deactivated and unused when the fifth servomotor is installed on the machine.

[0023] In one embodiment, at least the heated belt module and, alternatively, the LS sliding assembly or the HS drum assembly are mounted on the frame.

[0024] In this way, the frame serves as an assembly jig for the modules.

[0025] According to an embodiment, the frame includes a first plurality of advanced mounts and a second plurality of rearward mounts, and the belt module is mounted to the frame via either the first or second plurality of mounts.

[0026] In this way, the frame serves as a mounting jig for assembling the modules both at the machine manufacturer and after the machine has been delivered, ensuring compliance with the strict mounting tolerances required by the high product processing speeds on the machine.

[0027] BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will now be described non-restrictively with reference to the following drawings, in which:

[0029] Figure 1 is a perspective view of a modular machine according to the present invention in a first embodiment having a drum assembly (top) or in a second embodiment having a sliding module (bottom);

[0030] Figure 2 is a perspective view of a product (top) and a package made with sheet material (bottom) using the machine shown in Figure 1 ; Figure 3 is an exploded perspective view of some modules of the machine according to the present invention;

[0031] Figure 4 is an enlarged perspective view of the frame of the machine shown in Figure 1;

[0032] Figure 5 shows two details of an embodiment of the frame in the presence of the drum assembly (top) and the sliding assembly (bottom);

[0033] Figure 6 is a perspective view of another embodiment of the machine according to the present invention where, compared to Figure 1, a reel module differs; and

[0034] Figure 7 is a perspective view of a feeding module in another embodiment compared to Figure 1 , where a synchronizer is also present.

[0035] DETAILED DESCRIPTION OF THE INVENTION

[0036] Figure 1 illustrates two embodiments of a modular wrapping machine designed to package a product with sheet material into a parallelepiped-shaped package. The product is preferably, but not exclusively, a stack of two-dimensional items such as tissues, napkins, etc., or other unstacked items like matrices of rolls of kitchen or toilet paper and the sheet packaging material is for example cellulose- based, plastic materials such as polypropylene or low-density polyethylene (LDPE), or combinations thereof, e.g., polyethylene -coated paper (a multilayer structure with a cellulose-based layer and a plastic layer, e.g., polyethylene applied to the cellulose layer), supplied in reels.

[0037] Each machine (1) defines an "L"-shaped process path (P) and a process direction (F), indicated by arrows F, for a product (T) received, for example, in stacks and released at the end of the process path enclosed in a parallelepiped-shaped package (I) formed by folding and bonding a sheet of the packaging material. Figure 2 also shows the flaps (A) of the package folded and sealed / glued.

[0038] Each machine in Figure 1 includes at least one common module, onto which at least one other module can be mounted alternatively to achieve at least two distinct configurations differing in at least one process parameter, such as the maximum speed of packaged products per unit time or different dimensions, rigidity (soft or box-type), or other structural characteristics of the product (T) to be processed.

[0039] In more detail, the embodiment in Figure 1 includes the following common modules, which may, depending on the embodiment, be combined in various ways.

[0040] A product feeding module (Ml) includes a product conveyor and a transport servomotor (SI), for example, to drive a transport belt (N), chain, or similar. The servomotor (SI) is controlled to move the conveyor via a corresponding electronic machine axis, allowing temporal and spatial synchronization of the product with subsequent process stations of the machine. In one embodiment, the products to be covered with sheet material are pre-spaced correctly on the conveyor, and the servomotor (SI) is controlled to maintain temporal synchronization. In the embodiment shown in Figure 7, while the product (T) rests on the belt (N), a sequencer (S), including at least one corresponding servomotor, is controlled to spatially separate products supplied in bulk or too closely spaced according to a predefined step.

[0041] A product introduction module (M2) includes a corresponding servomotor for performing a product preparation operation such as compressing or aligning the product (T) before its first interaction with the sheet material. Compression may be vertical (e.g., for a stack of napkins) or lateral (e.g., for a matrix of paper rolls). Alignment may be performed when the sheet material is bundling two stacked or side-by-side boxes to achieve a defined relative position between the boxes, e.g., in contact or stacked, in either case without undercuts. This is achieved in various ways, e.g., by synchronized pushers acting to achieve the desired position with or without box compression, monitored by a camera. For instance, the introduction module M2 also includes a second synchronized servomotor to change the direction of product T relative to the feeding module Ml.

[0042] A reel-holder module M3 includes a support controlled by a servomotor to maintain a reel (not shown) on a predefined axis, e.g., horizontal, and to unwind the reel, providing the predefined sheet length suitable for completing the package around the product T. Figures 3 and 6 illustrate two different embodiments of corresponding reel-holder modules M3 and Ml 3.

[0043] An unwinding and cutting module M4 includes guide rollers and at least one pulley or roller tensioner (not shown) to guide the sheet material from the reel to the product T while maintaining a predetermined tension or a tension within a range of values and a cutting servo-actuator S3 to cut the desired length of packaging material synchronously with the constant advancing step of the product T along the process path P. For instance, the reel has an optical mark related to the position of a repeated print on the sheet material and the module M4 includes a sensor, e.g., optical, to detect this mark, after cutting the sheet, appropriate actuators position the cut sheet relative to the product T so that the print is in a desired relative position. It is noteworthy that as the reel unwinds, its diameter decreases and thus, module M3 must synchronize with the machine's step but apply a variable motion law based on the remaining paper quantity on the reel since the diameter decreases during the use and, thus, the reel rotation speed must be increased to achieve the same sheet length to be cut, e.g., to allow the sensor to detect two consecutive marks. A base frame M5, mounted on the floor during use and comprising a plurality of interfaces and mounting attachments to rigidly and removably secure one or more modules of the machine. The interfaces and mounting attachments comprise various components commonly used in machinery assembly to achieve rigid and removable fixing, such as holes, studs, bolts, pins, etc.

[0044] A belt module M6 having a transport servo-actuator S4 for driving belts preferably arranged on opposite sides of the product T and a bonding heater S5 for sealing the sheet material or reactivating previously applied glue to affix the folded flaps A by welding or bonding. The belt module M6 outputs the product T wrapped in the folded sheet material, and the frame has rearward attachments Al and forward attachments A2 (relative to the arrow F) for mounting the belt module M6 in a corresponding forward or rearward position.

[0045] It is common to the modular machines an electrical panel QE that controls the machine axes of the servo-actuators / servo-motors mentioned above and those of the assemblies described in the following paragraphs. Specifically, the electrical panel houses the electronic servo-controllers to power at least some of the machine's servoactuators. These servo- controllers can also receive / send command and feedback signals to and from the corresponding servo-actuators. Additionally, the electrical panel includes a control unit, preferably implemented with PLC elements, which exchanges data with the servo-controllers, the sensors of the machine 1, and with that of the servo-motors. The servo-motors include at least rotary or linear electric motors and onboard sensors to provide feedback for motor control. Servo-controllers can be onboard the servo-motors, but at least a plurality of the servo- controllers are mounted in the electrical panel QE and connected to the corresponding servo-motors via power supply cables. the electrical panel QE and connected to the corresponding servo-motors.

[0046] The control unit is programmed to store at least two machine cycles, each representing a phase diagram linking the positions of the servo-motors to a virtual axis completing 360° during each machine cycle in which the product advances one step along the machine. According to one embodiment of the modular concept of machine 1, the electrical panel QE is pre-installed with a plurality of servocontrollers, and the control unit is preloaded with a plurality of machine cycle functions for the corresponding servo-actuators in a way to ensures that in at least one machine configuration, there is at least one unused servo- controller and / or one deactivated machine cycle function because the corresponding servo -actuator is not present in that configuration. A machine cycle function is a software routine that governs the motion of a corresponding servo-actuator during a machine cycle. Since the machine 1 can be configured in at least two ways, the control unit stores at least two machine cycles — for example, one for a configuration with relatively low processing speed and another for a configuration with relatively high processing speed.

[0047] Alternatively, only the electronic servo-controllers for the product feed module Ml, the product introduction module M2, the reel holder module M3, the cutting module M4, and the belt module M6 there are in the electrical panel QE. Depending on the final configuration of the machine, additional servo-controllers for other assemblies or modules are then added, e.g., those associated with the low- speed configuration or the high-speed configuration.

[0048] For example, sensor signals processed by the control unit include upstream and downstream consent signals, product presence in one or more machine stations (e.g., at the entry of one or more modules), reel presence onboard the machine, the presence of the mark on the sheet referenced earlier, and excessive torque in one or more servo-motors, indicating for example jams.

[0049] Preferably, the electrical panel QE is part of the reel module M3, as this module is present in all configurations achievable through the modules. Additionally, in a preferred embodiment of the present invention, at least the power cabling between the electrical servo-controllers and servo-actuators has a length that allows them to be shared between at least two modules present alternatively in two different configurations of the machine 1 , or to be applied to the same module which changes position in two different configurations of the machine 1.

[0050] According to the present invention, between the product feed module Ml and the belt module M6, either a low-speed sliding group M7 or a high-speed drum group M8 is mounted on the frame M5. To reduce potential assembly errors, the frame M5 defines a first mounting interface IM1 for the sliding group M7 and a second mounting interface IM2 for the drum group M8 and the mounting interfaces IM1 and IM2 are configured so that the sliding group M7 cannot be mounted (e.g., due to interference or similar issues) on the second mounting interface IM2, and the drum group M8 cannot be mounted (e.g., due to interference or similar issues) on the first mounting interface IM1. mounting interface IM1

[0051] The groups M7 and M8 define a station on the machine where the product T is wrapped with the sheet material along four consecutive sides. The lateral zones of the sheet material are then folded in the belt module M6 to become flaps, which are glued or welded. In the low-speed sliding group M7, during each step, the product T is loaded onto the group, wrapped on four sides with the sheet material in a known manner during a single machine step, as described, for example, in EP1260437. According to one embodiment, the group M7 is configured to wrap the sheet material around the product T and apply glue or weld it along a line adjacent to the product introduction module M2. The group M7 includes multiple servo-motors acting on the product T and / or the sheet material. During each machine step, the sliding group M7 a single product T to be processed is present.

[0052] The high-speed drum group M8 comprises, as known and described, for example, in EP3212507, a rotating drum driven by a servo-motor with a horizontal axis, onboard of which, for each step, more than one product T is present, preferably three products T are provided in corresponding angularly equidistant positions, one of which, the lower one, is empty. In three steps onboard the drum, the product is wrapped on three consecutive sides with the sheet material, glue is applied, or the material is welded along the fourth consecutive side of the product T and the resulting semi-finished product is then transferred facing the belt module M6, where, in subsequent steps, the lateral flaps A are folded and glued / welded. Due to the drum’s rotation, the glue or welding on the fourth consecutive side is positioned to face the belt module M6 when the product T exits the high-speed module M8. The seat onboard the drum can be more than four, and the machine cycle is adapted accordingly.

[0053] According to one embodiment, the electronic control unit receives as input a parameter representative of the servo-motors connected for power supply and data exchange with the electrical panel (QE). This parameter can be simple, e.g., the number of servo-actuators, if each input number corresponds to one and only one machine configuration. Based on this input to the control unit, the machine cycle functions of the configuration to which the number refers are automatically identified, for instance, through a pre-stored list where each input number is associated with a list of machine cycle functions and the corresponding list of servo - actuators that execute them. For example, the parameter is manually entered by the user through an appropriate I / O interface connected for data exchange with the electronic control unit.

[0054] This further simplifies both the assembly of the machine in the manufacturing workshop and the installation of a module purchased after the machine has already been put into operation.

Claims

CLAIMS1. Wrapping machine defining a processing path for a parallelepiped product (T) to be packaged, comprising:- In one or more modules: a product feeding unit (Ml) having at least one conveyor with a first servo-motor; an introduction unit (M2) receiving the product (T) from the conveyor and having a second servo-motor to perform preparation of the product (T), such as compression or alignment; a reel -holder unit (M3) having a third servo-motor for moving a reel of sheet material; a frame (M5);- a heated belt module (M6) for heating to reactivating an adhesive applied to the sheet material wrapped around the product (T) or for sealing the sheet material wrapped around the product (T) in a package and securing opposing lateral flaps (A) of the package applied around the product (T) using appropriate folding guides designed to cooperate with the flaps (A), mountable preferably in a first more forward position and a more rearward position with reference to a processing direction of the product along the processing path;Alternatively, positioned between the introduction unit (M2) and the heated belt module (M6):- In one or more modules: a slide group (M7) positioned upstream of the belt module (M6) with reference to the processing direction and downstream of the conveyor, for wrapping the product with the sheet material; orIn one or more modules: a wrapping group (M8) configured to wrap the sheet material from the reel-holder module (M3) around the product and having a second processing parameter, such as a second maximum processing speed or a second maximum product size, larger than the first processing parameter, and a sixth servomotor to wrap the sheet material or move the product;Wherein:- the frame (M5) comprises a first mounting interface (IM1), preferably holes, to mount the slide group (M7) and a second mounting interface (IM2), preferably additional holes, to mount the drum group (M8), the first and second interfaces being configured such that the slide group cannot be mounted on the second interface and the drum group cannot be mounted on the first interface.

2. A machine according to claim 1, wherein at least the servo-motors of the feeding module (Ml), the introduction module (M2), and the cutting module (M4) are synchronized using a phase diagram with a virtual axis that completes 360° for each machine cycle.

3. A machine according to any of the preceding claims, wherein the frame (M5) extends in a first direction and the feeding module (Ml) extends in a second direction, and the first and second directions are transverse, preferably perpendicular.

4. A machine according to any of the preceding claims, comprising a control unit and an electrical panel (QE) containing a plurality of electronic servo - controllers for said servo-actuators and connected for data exchange with the plurality of servo-controllers, wherein at least one servo-controller from said plurality is pre-mounted in the electrical panel, pre-connected for data exchange with the control unit, and disconnected from said servo-actuators when the machine is in use.

5. A machine according to claim 4, wherein a control unit is programmed to store at least one machine cycle function for each of said servo - actuators and to receive as input at least one piece of data representative of the servomotors connected for data exchange and power supply with the electrical panel (QE) and to associate, based on said data, each pre-stored machine cycle function with the corresponding servo-actuator, wherein at least one machine cycle function for a servo-actuator remains deactivated when the machine is configured according to said data because the corresponding servo-actuator is not present on the machine configured according to said data.

6. A machine according to any of claims 4 or 5, wherein the electronic control unit is connected for data exchange with a plurality of sensors generating corresponding signals, including signals from the servomotors, upstream and downstream approval signals, product presence signals in one or more stations of the machine, reel presence on the machine, and excessive torque in one or more of the servomotors.

7. A machine according to any of claims 4 to 6, wherein the electrical panel (QE) is part of the reel-holder module (M3).

8. A machine according to any of the preceding claims, wherein at least one other module among the said feeding module (Ml), introduction module (M2), reel-holder module (M3), and heated belt module (M6), is mounted on the frame (M5).

9. A machine according to claim 7, wherein the frame (M5) has a first plurality of forward mounting points and a second plurality of rearward mounting points, and the heated belt module (M6) is mounted on the frame via the first or second plurality of mounting points, respectively, when the machine comprises the drum group (M8) or the slide group (M7).

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