Device for stacking flexible packaging

Abstract

Device (1) for stacking flexible packaging (2) containing bulk goods, such as bags of tubers or ground material, comprising: ▪ a feed group (3) for the packaging; ▪ a stacking group with a base support frame (11) defining a receiving space (10) for a platform (9) on which the packages (2) are stacked, wherein the platform (9), when arranged in the receiving space (10), has a surface substantially in a stacking plane; ▪ a transfer unit (4) with a gripping element (5) configured to capture and release the packages (2); the transfer unit (4) is configured to transfer packages (2) from the feed group (3) to the stacking group and release them above the platform (9) to determine their position and orientation above the receiving space (10); ▪ a compacting unit (6) configured to extend around the receiving space (10) in a top view according to a top view of the receiving space (10); the compacting unit (6) is configured to compact layers of packaging (2) placed successively on the platform (9) such that the base area of ​​each layer in said top view is substantially the same as the base area of ​​each subsequent layer.

Description

TECHNICAL AREA

[0001] The present invention relates to the field of industrial systems for handling and stacking deformable load units, in particular flexible packaging containing bulk goods, by means of an automatic device configured to create palletized structures suitable for storage, handling and transport. STATE OF THE ART

[0002] Prior art provides for automatic devices for stacking flexible packaging containing bulk goods, such as bags of vegetables or granular material, which are unstable under load and require special measures to form regular stacks. A typical solution in the prior art involves the use of a cuboid receiving box, often in the form of a rigid trough or structure with inflexible perimeter walls, within which the packaging is placed layer by layer by a handling robot. The walls of the box act as mechanical restraints to hold and align the individual bags, thus compensating for their deformability and preventing misalignment during vertical stacking.

[0003] However, such solutions have significant operational drawbacks. In particular, the movements required of the palletizing robot are extensive and complex, as it must precisely position each package within the volume limited by the container, thus impairing efficiency and increasing cycle times. Furthermore, the structural complexity of the container, which must withstand the stresses of progressive filling and the lateral forces of the bags, significantly impacts costs, space requirements, and maintenance. A known alternative solution is stacking using an anthropomorphic arm, which enables high stacking accuracy but has cycle times that still have considerable room for improvement.

[0004] Consequently, there remains a need for alternative solutions that make it possible to obtain compact and geometrically uniform stacks of deformable packaging, eliminating the need for rigid containers and simplifying the kinematics of automatic palletizing systems. TECHNICAL TASK

[0005] The automated stacking of flexible packaging containing bulk goods, such as bags of vegetables or granular material, presents significant operational challenges due to the inherent deformability of the packaging and the geometric variability of the products inside. Without rigid containers or boundary walls, forming orderly and stable stacks requires technical solutions capable of compensating for the unstructured mechanical behavior of the packaging.

[0006] The purpose of the present solution is to address and solve this technical problem by providing a system that ensures the alignment, stability, and geometric uniformity of each stacked layer, even under dynamic operating conditions and without fixed boundaries.

[0007] Within the scope of this task, one objective of the present solution is to provide a method and a device that enable and simplify the plant architecture and reduce its space requirements and mechanical complexity.

[0008] Another goal is to provide a solution that makes it possible to limit the range and complexity of the movements required by the robot or transmission unit and to improve the kinematics of the entire system.

[0009] Another goal of the solution is to optimize the palletizing sequence and cycle times.

[0010] The solution also aims to achieve a regular design for each layer of stacked packaging.

[0011] One objective of the present solution is to ensure that the base area of ​​each layer is essentially constant in order to guarantee an essentially cuboid profile with high overall regularity of the stack formed.

[0012] Furthermore, devices should be made available that allow parametric adjustment of the height and interaction forces with the packaging, depending on the type and physical properties of the contents of the manipulated packaging.

[0013] Another objective is to integrate all operational functions—including feeding, transfer, compaction, and control—into a single, coordinated architecture, thereby reducing the need for separate subsystems and simplifying plant management. Finally, the solution aims to improve the stability of the palletized unit after stacking is complete, facilitating rewrapping, transport, or automated storage, and enabling rapid adaptation to different product formats without invasive mechanical intervention. SUMMARY OF THE INVENTION

[0014] For the purposes of this description, the term "flexible bulk packaging" refers to loading units consisting of a deformable container (typically a bag made of plastic, mesh, or bonded film) filled with solid, non-cohesive products. These products may consist of discrete elements of variable shape and size, such as vegetables (e.g., potatoes, onions), granules, crushed or otherwise fractionated materials, which exhibit internal mobility and unstable behavior under load, resulting in geometric changes to the bag during handling or stacking.

[0015] In other words, these are deformable units without intrinsic structural stiffness that conform to the shape imposed by external constraints (such as overlapping bags or boundary walls) and tend to produce protrusions, lateral deformations, or instabilities when palletized without restraint.

[0016] Corresponding terms used in the present application, such as "flexible bag", "deformable casing for granular products", "bulk load in flexible packaging" or "loading unit with variable geometry", are to be understood as technically equivalent to the definition given above.

[0017] According to a first aspect, the invention relates to a device for stacking flexible packaging containing bulk goods, such as bags of lumps or ground material. This device can comprise a feeding unit for the packaging, a stacking unit with a base support frame that defines a receiving space for a platform on which the packaging is placed, and a transfer unit with a gripping element for grasping and releasing the packaging in a defined position and orientation.

[0018] According to the present solution, a compaction unit can be provided which extends around the receiving space and which includes a work carrier frame and a plurality of side elements which are movable between an open and a closed position and are configured to exert a lateral compaction of the successive packaging layers.

[0019] This compaction unit can be moved vertically in the stacking direction, for example via a motorized column, to position itself at the working height of the layer level to be compacted.

[0020] The lateral components can number four, arranged orthogonally to each other, each having a substantially flat pressure surface facing inwards and forming a working circumference in the closed position that corresponds to the shape of the underlying platform. This ensures a regular and uniform geometric state for each stacked layer.

[0021] A mechanical transmission with a safety clutch can be provided to protect the components in case of overload. The movement of the lateral components can be performed with differentiated speed profiles: high speed during the approach phase and reduced speed during the final phase (i.e., during interaction with the packaging) to optimize cycle times and precision.

[0022] The compacting unit can include integrated sensors to detect working heights, the position of side organs, and contact pressure, thus enabling parametric setting and automatic adjustment of operations.

[0023] An integrated control system can be provided that coordinates the compaction unit with the transfer unit, so that the compaction phases are carried out in parallel with the formation of the next layer by the gripping element, without affecting the cycle of the palletizing robot.

[0024] The transmission unit can include a multi-axis manipulator equipped with a vertical column and a movable boom, coupled with a gripping device to perform combined vertical, transverse, and rotational movements around the platform.

[0025] Furthermore, the device may include drive means that coordinate the transmission, compaction and stacking groups to ensure the automatic synchronization of the stacking and compaction operations layer by layer.

[0026] According to another aspect, the invention relates to a method for stacking flexible packaging containing bulk goods.

[0027] This process can include a step A in which a package is placed on the platform in a predefined position and orientation, followed by a step B in which a fully formed layer is compacted perpendicular to the stacking direction.

[0028] Steps A and B can be performed alternately and repeatedly until a stack is formed, which may be completed by step C of final packaging to stabilize the palletized unit for further transport or storage.

[0029] In a preferred configuration, the compaction step B can occur simultaneously with the formation step A of the next layer, thereby maximizing the time efficiency of the entire operating cycle.

[0030] The procedure can be carried out using a device that corresponds to one of the configurations described above.

[0031] The feeding and compacting units can gradually rise as the layers are formed to minimize the positioning times of the packages by the transfer unit.

[0032] In particular, the feeding group can include a vertically movable output area in the stacking direction, configured to be positioned at an optimized dispensing height to reduce the range of motion of the gripping element and to accelerate the transfer of the packages.

[0033] This enables significantly higher overall performance compared to conventional solutions.

[0034] It is therefore understood that the features shown can be implemented in one or more of the aspects specified for the present solution. DESCRIPTION OF THE FIGURES

[0035] Detailed features of a method and an apparatus for stacking flexible packaging according to the present solution are specified in the dependent claims.

[0036] Further features and advantages of the invention will become clearer from the description of a preferred, but not exclusive, embodiment of a method and apparatus for stacking flexible packaging, which is illustrated in an exemplary, non-limiting embodiment in the accompanying drawings, wherein: ▪ Fig. Figure 1 shows a schematic perspective view of an apparatus according to the present solution. DETAILED DESCRIPTION

[0037] With reference to the aforementioned figure, the present solution relates to a device 1 for stacking flexible packaging 2 containing bulk goods, such as bags of tubers or ground material, intended to form an ordered stack on a platform 9.

[0038] The device can include a feed unit 3 for the packages 2, configured to supply one or more packages 2 to a transfer unit 4. This transfer unit 4 can include a gripper 5 configured to individually grasp, transport, and place each package 2 on the platform 9 in a predefined position and orientation.

[0039] The platform 9 can be arranged in a receiving space 10, which is defined by a base support frame 11, the upper surface of which lies essentially in a stacking plane.

[0040] According to the invention, the device 1 can include a compacting unit 6 configured to extend around the receiving space 10 in a top view and serving to compact the successive layers S1, S2 of packages 2 placed on the platform 9, so that each layer has the same footprint, uniform with the others. The stacking unit can define a stacking direction Z extending vertically from the receiving space 10.

[0041] The compacting unit 6 can comprise a work carrier frame 12, which is movable along the stacking direction Z, as well as a plurality of compaction elements 13, which are extensively connected to the frame 12 and configured to extend in transverse directions X, Y to the stacking direction Z. This structure makes it possible to exert lateral pressure on the packaging 2 of each individual layer.

[0042] The compression elements 13 can be movable between an open position, in which they release access to the receiving space 10, and a closed position, in which they form a boundary frame for a layer of packaging 2.

[0043] The compaction elements 13 can be designed such that, in the closed position, they define a perimeter in plan view that essentially corresponds to that of the platform 9. This can make it possible to stack all layers S1, S2 ... geometrically uniformly along direction Z, even in the absence of a rigid outer container.

[0044] Each compaction element 13 can have a substantially flat pressure surface 13a designed to interact with the outer profile of the packaging 2 and compact it so that the resulting base area of ​​the layer corresponds to the imprint of the platform 9. The compaction unit 6 can be movable relative to the base support frame 11 along the Z direction, for example by means of a motorized column 14. In this way, the compaction unit 6 can be positioned at a variable working height corresponding to the level of the layer being formed.

[0045] The feed group 3 can include an output area 3a configured to provide the packaging 2 to the transfer unit 4. The output area 3a can be movable along the Z direction, allowing it to be positioned at a variable dispensing height, thereby minimizing the stroke of the gripper 5 for transferring the packaging 2.

[0046] The transmission unit 4 can be designed as a multi-axis manipulator and comprise a column unit 4a, a boom unit 4b and the gripping element 5.

[0047] The column unit 4a can guide the vertical movement V and the rotary movement R of the boom unit 4b, while the latter enables a transverse movement and rotary movement of the gripping element 5, thus ensuring maximum flexibility in positioning.

[0048] Drive units, not shown here, can be provided to coordinate the movements of the transfer unit 4, the compacting unit 6, and the stacking group, thus achieving a synchronized cycle in which each layer is efficiently stacked and compacted. Compared to the prior art, the present solution allows fixed boundary structures to be replaced by a dynamic, adaptive system that replicates the geometric constraint function only at the required time and height. The result is a significant reduction in mechanical complexity and cycle times, combined with greater geometric uniformity and stability of the stack, achieved through active, parameterizable means that can be fully integrated into existing palletizing systems.

[0049] The solution also relates to a method for stacking flexible packaging 2 containing bulk goods on a platform 9 using a device 1 as described above.

[0050] The process may include a step A in which at least one of the packages 2 is grasped by a gripping device 5 and placed on the platform 9.

[0051] The storage can take place in a position and orientation that is predefined relative to platform 9, so that an ordered stack is progressively built up along the stacking direction Z.

[0052] Step B can follow, in which, after the formation of a complete layer of packaging 2 in step A, the compaction unit 6 is activated to exert a transverse pressure on the layer. The compaction elements 13 move inwards and laterally compact the layer S1, S2 to reduce the base area to a perimeter P that essentially corresponds to that of the platform 9.

[0053] The procedure may involve repeating steps A and B alternately until the stack is completely formed.

[0054] Compaction step B can be performed partially or completely simultaneously with formation step A; that is, while the gripping element 5 picks up a package 2 to form another layer S2, compaction step B is carried out. This allows for the synchronization of the processes and a significant reduction in cycle times.

[0055] According to a further embodiment, the method can include a step C in which the stack thus formed is packaged, for example by wrapping it with a plastic film or similar material, to prevent displacement or deformation during handling, transport or storage.

[0056] Thanks to this method, it is possible to achieve the previously described objectives: the elimination of fixed boundary structures, the simplification of the robot systems' kinematics, the reduction of the required movement paths for positioning, the guarantee of a consistent geometric design for each layer, the assurance of the stack's final stability, and dynamic adaptation to varying operating conditions. In particular, the solution allows for the replacement of static boundary control with active dynamic compaction, which is executed at the appropriate time and only to the necessary extent. This transition from passive boundary control to active control represents a functionally new approach to handling unstable loads.

[0057] The method, when carried out with a device 1 such as that described above, integrates and coordinates the functions of gripping, depositing, compacting and controlling, operates continuously, efficiently and adaptably, and represents a significant advancement over prior art solutions.

[0058] It is therefore clear that the present solution achieves the stated task and the set objectives by providing a method and a device for stacking flexible packaging that ensures the formation of geometrically uniform stacks without the use of rigid containers, through active and coordinated lateral compaction that acts selectively on each stacked layer.

[0059] The ability to synchronize the depositing and compaction steps allows for a significant reduction in cycle times without sacrificing precision or stability.

[0060] The adjustable working height of the compaction unit, along with the configurable output area, enables automatic adaptation to varying operating conditions and allows the system to minimize gripper movements. The complete integration of feeding, transfer, compaction, and control results in a functionally unified architecture, which increases overall reliability and reduces the system's mechanical complexity.

Claims

[1] Device (1) for stacking flexible packaging (2) containing bulk goods, such as bags of tubers or ground material, comprising: ▪ a feed group (3) for the packaging; ▪ a stacking group with a base support frame (11) defining a receiving space (10) for a platform (9) on which the packages (2) are stacked, wherein the platform (9), when arranged in the receiving space (10), has a surface substantially in a stacking plane; ▪ a transfer unit (4) with a gripping element (5) configured to capture and release the packages (2); the transfer unit (4) is configured to transfer packages (2) from the feed group (3) to the stacking group and release them above the platform (9) to determine their position and orientation above the receiving space (10); ▪ a compacting unit (6) configured to extend around the receiving space (10) in a top view according to a top view of the receiving space (10); the compacting unit (6) is configured to compact layers of packaging (2) placed successively on the platform (9) such that the base area of ​​each layer in said top view is substantially the same as the base area of ​​each subsequent layer. [2] Device according to claim 1, wherein the stacking group defines a stacking direction (Z) extending vertically from the receiving space (10) when the device (1) is in operation; wherein the compacting unit (6) comprises a work carrier frame (12) and compacting elements (13) which are extensibly connected to the frame (12) to extend in compaction directions transverse to the stacking direction (Z). [3] Device according to claim 2, wherein the compacting elements (13) are movable on the frame (12) between an open position and a closed position; the compacting elements (13) are shaped and movable such that in the closed position they form a frame which, in plan view with respect to the receiving space (10), defines a working area which essentially corresponds to that of a platform (9) which is arranged in operation in the receiving space (10), so that layers of packaging (2) are stacked geometrically uniformly along the stacking direction (Z). [4] Device according to claim 3, wherein the compacting elements (13) each have a substantially planar pressure surface (13a) designed to interact with and compact the packagings (2), and positioned such that in the closed position each pressure surface (13a) is directed inwards towards the working circumference to compact the packagings (2) so that they assume a base surface substantially congruent with the platform (9) in plan view, on which they are stacked in operation. [5] Device according to claim 1 and one of claims 2 to 4, wherein the compacting unit (6) is movable relative to the frame (11) along the stacking direction (Z) so that it can be positioned at a stacking height on which a layer of packaging (2) is formed during operation of the device (1). [6] Device according to claim 1 and one of claims 2 to 5, wherein the feed group (3) comprises a discharge area (3a) in which it provides at least one package (2) to the gripping element (5) of the transfer unit (4) for transfer into the stacking group, wherein the discharge area (3a) is movable along the stacking direction (Z) so that it can be positioned at a discharge height at which, during operation of the device (1), the movement of the gripping element (5) is minimized in order to transfer a package (2) from the discharge area (3a) to the layer of packages (2) to be formed. [7] Device according to claim 1 and any one of claims 2 to 6, wherein the transmission unit (4) comprises a multi-axis manipulator comprising a column unit (4a), a boom unit (4b) connected to the column unit (4a), and the gripping element (5) connected to the boom unit (4b); wherein the column unit (4a) is configured to guide a movement of the boom unit (4b) along and around the stacking direction (Z), and wherein the boom unit (4b) is configured to guide a movement of the gripping element (5) transverse to and around the stacking direction (Z). [8] Device according to claim 1 and one of claims 2 to 7, comprising drive means (15) connected to the transmission unit (4), the stacking group and the compacting unit (6) to coordinate their operations during operation such that layers of packaging (2) are stacked on a platform (9) arranged in the receiving space (10), each stacked layer being compacted by the compacting unit (6) before another layer is formed on top of it.

Images