Alignment device and method for aligning laminated sheet in a corrugated board laminator

Abstract

The alignment device for aligning a laminated sheet includes, in order in a forward feeding direction (DR) of the laminated sheet (100): a first conveying unit (B0) configured to convey the laminated sheet (100); an acceleration roller (R2) configured to increase a conveyance speed of the laminated sheet (100); and a second conveying unit (B1). The second conveying unit (B1) comprises at least one movable abutment element (46) arranged transversely to said forward feeding longitudinal direction (DR) of the laminated sheet and configured to align the laminated sheet (100).

Description

Technical Field

[0001] The present invention relates to the field of production of laminated corrugated board, in particular to a corrugated board laminating machine. The present invention is particularly developed for an alignment device for aligning laminated sheets and a method for aligning laminated sheets. Background Art

[0002] In many industrial applications, it is known to apply laminated sheets (e.g. sheets that have been pre-printed and cut to size) to multi-layer composite materials (e.g. corrugated board). One of the reasons for this choice is that printed sheets or using printed sheets directly in the corrugated board plant do not achieve the required quality, since online printing does not guarantee the same results as printing individual sheets, and the board in the production plant is subject to environmental conditions, temperature and humidity, which can affect the properties of the laminated sheet.

[0003] For these and other reasons, corrugated board, either in the form of a continuous web or individual sheets, is joined together with a laminate at the end of the corrugated board manufacturing process.

[0004] One of the main problems with this solution is ensuring that the laminate is perfectly aligned with the corrugated cardboard web or sheet, both along the sides and at the front, before being combined with the corrugated cardboard web or sheet. Otherwise, the laminate may leave exposed sections of the cardboard that must be trimmed or discarded, but in particular, images, text or patterns present on the laminate may not be aligned with the cardboard itself.

[0005] Alignment devices are known, such as those described in FR 2 857 655, that use translational members to modify the relative position of laminated sheets. In this solution, two independent translational members move the laminated sheet until at least one side edge and the leading edge of the sheet are aligned with at least one side edge and the leading edge of a cardboard sheet or web. These solutions are sometimes not particularly precise and, in any case, necessarily involve a series of sensors capable of detecting the various relative positions that the laminated sheets can assume during the alignment process, resulting in a particularly complex arrangement.

[0006] Other known types of devices, such as that described in EP 0 733 467 , include cutting blades that cut the cardboard web or sheet to size depending on the position of the leading or trailing edge of the laminate, thus allowing it to be aligned. These solutions present significant problems with precision and, in any case, result in a large amount of cardboard being discarded.

[0007] All known solutions therefore have numerous drawbacks related to the complex operation of the components used (eg numerous sensors), the complexity of the alignment operations (eg numerous displacements required to achieve a correct alignment) and the difficulty in maintaining high lamination speeds due to the numerous operations that must be performed.

[0008] Therefore, there is a need to provide an alignment device that overcomes or significantly reduces the above disadvantages. Summary of the Invention

[0009] This need is met by the characterizing features of the invention set out in the independent claim.The dependent claims define preferred and / or particularly advantageous features of the invention.

[0010] It is to be understood that elements and characteristic features of one embodiment may be incorporated in other embodiments without further recitation. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Reference will now be made in detail to various embodiments of the present invention, and particularly to the accompanying drawings, in which:

[0012] - Figure 1 shows a schematic layout of the end portion of a plant for producing laminated corrugated board;

[0013] - Figure 2 is a schematic planar representation of a plurality of laminated sheets;

[0014] - Figure 3 shows a schematic side view of an embodiment of an alignment device according to the present invention;

[0015] - Figure 4 yes Figure 3 A schematic side view of a first motorized conveyor unit of the apparatus shown in ;

[0016] - Figure 5 yes Figure 3 Another side view of the device shown in;

[0017] - Figure 6 It's seen from above Figure 3 A view of the alignment device shown in;

[0018] - Figure 7 is an axonometric view of a second motorized conveyor unit with a movable abutment element according to the present invention;

[0019] - Figure 8 yes Figure 7 A schematic side view of

[0020] - Figure 9a 、 9b and 9c are front views of the end portion of the second motorized conveying unit in three different operating states;

[0021] - Figure 10 is a schematic side view of another embodiment of an alignment device according to the present invention;

[0022] - Figure 11is a schematic side view of another embodiment of an alignment device according to the present invention;

[0023] - Figure 12 It's seen from above Figure 11 A view of the device shown in;

[0024] - Figure 13 is a schematic side view of one embodiment of an alignment device according to the present invention; and

[0025] - Figure 14 is a schematic side view of a corrugated board laminating machine comprising an alignment device according to the invention. DETAILED DESCRIPTION

[0026] Each example is intended solely to illustrate the present invention and should not be construed as limiting the present invention. For example, because the technical features shown or described constitute part of one embodiment, they may be incorporated into or associated with other embodiments to create additional embodiments. It should be understood that the present invention encompasses such modifications and variations.

[0027] Figure 1 The layout of one of the possible embodiments of the end portion of an apparatus for producing laminated corrugated board comprising a corrugated board laminating machine according to the invention, in particular an alignment device for aligning the laminated sheets, is shown.

[0028] In this equipment part, the following components are present: a laminated sheet magazine 1, or sheet feeder, which is configured to store a plurality of laminated sheets 100; an inlet 5 for a multi-layer composite paperboard web; an area 4 for depositing glue onto the web of multi-layer composite paperboard 110; an area 2 for conveying the laminated sheets 100 in a forward feed direction DR; and a lamination area 3 for joining the laminated sheets 100 to the multi-layer composite paperboard 110.

[0029] Obviously, the incoming web of the multi-layer composite paperboard web 110 can be composed of a single flute or single face, or a corrugated paper web (corrugated paper web) bonded to a flat paper web (liner). According to other embodiments, the incoming web of the multi-layer composite paperboard 110 can be composed of a double flute or double face, which is formed by two flutes pre-bonded together. Furthermore, the incoming multi-layer composite paperboard can be a corrugated paperboard having a single or double corrugation, i.e., a single flute or a double flute, and also including a liner.

[0030] In other possible embodiments, a plurality of single multi-layer composite paperboard sheets 110 having predetermined sizes may be provided at the inlet 5 .

[0031] Each laminating sheet 100 comprises a front edge 101, a rear edge 102 and two side edges 103. In order to be able to achieve correct lamination 3 of the laminating sheet 100 together with the sheet or web of multilayer composite paperboard 110, in the lamination area 3, the conveying speed of the sheet or web of multilayer composite paperboard 110 and the speed of the laminating sheet 100 must be the same, and at least the front edge 101 and at least one side edge 103 of the laminating sheet 100 must be perfectly aligned with the front edge 111 and side edges 113 of the sheet or web of multilayer composite paperboard 110.

[0032] The alignment device for aligning the laminated sheets according to the invention, generally indicated by 10, is arranged between the area 2 for conveying the laminated sheets and the laminating area 3 for joining the laminated sheets to the multi-layer composite paperboard. The alignment device 10 defines a sliding / conveying plane for the laminated sheets 100, which are conveyed in a forward feed direction DR that substantially corresponds to the forward feed path of the multi-layer composite paperboard along the production plant.

[0033] The alignment device 10 according to the present invention comprises a first motorized conveying unit B0 for conveying the laminated sheet 100 .

[0034] exist Figure 4 In the illustrated embodiment, the first motorized conveyor unit B0 includes at least one belt 22 coupled to a first shaft 24 and a second shaft 25, and a separate actuator. Each of the shafts 24 and 25 has an axis of rotation, and at least one of the shafts is connected to the actuator to rotate about its axis of rotation and move the belt 22, thereby allowing the laminated sheet 100 to be conveyed in the forward feed direction DR. The belt 22 forms a sliding / conveying plane for the laminated sheet 100.

[0035] The first motorized conveyor unit B0 may also include one or more pressure rollers 26 arranged above the belt 22 and designed to facilitate conveying and positioning stability of the laminated sheet 100 .

[0036] In other embodiments, the first motorized conveyor unit B0 comprises a belt with a plurality of through openings (holes) and a suction system for facilitating the conveying and positioning stability of the laminated sheet 100 on the belt itself.

[0037] The alignment device 10 comprises a second motorized conveyor unit B1 for aligning the laminated sheets 100 , which is arranged downstream of the first motorized conveyor unit B0 along the feed path of the laminated sheets 100 in the forward feed direction DR.

[0038] The second motorized conveyor unit B1 includes at least one pair of belts 42, a pair of shafts 44, 45 on which the at least one pair of belts 42 are mounted, and an independent actuator 41 connected to at least one of the pair of shafts 44, 45. Each belt 42 has a predetermined perimeter development lengthwise and width, so that the sum of the widths of the belts 42 allows forming a sliding / conveying plane for the laminated sheet 100.

[0039] Each of the shafts 44 , 45 has a rotation axis, and at least one of the shafts 44 is connected to the actuator 41 to rotate about its rotation axis and move at least one pair of belts 42 and allow the laminated sheet 100 to be conveyed in the forward feed direction DR.

[0040] according to Figure 6 and Figure 7 In the embodiment shown, the second motorized conveyor unit B1 includes six belts 42 mounted on a pair of shafts 44, 45 and evenly distributed along the length of the shafts 44, 45. In other embodiments, the number, width and distribution of the belts 42 may vary. Figure 6 and Figure 7 The illustrations shown can vary greatly, as long as the belts 42 form a sliding / conveying plane for the laminate 100. For example, it is conceivable to have only three belts 42 of greater width, or twelve belts of lesser width, which are always evenly distributed along the length of the shafts 44, 45.

[0041] The second motorized conveyor unit B1 comprises at least one movable abutting element 46 engaging with each belt 42. Each movable abutting element 46 comprises at least one longitudinally elongated abutting wall 47. Each movable abutting element 46 is arranged on the corresponding belt 42 such that the abutting wall 47 is arranged transversely to the extension of the belt 42, i.e. transversely to the longitudinal axis coinciding with the forward feed direction DR.

[0042] Special References Figure 7 , and as will be more clearly shown below, when the abutment elements 456 are aligned with each other along the longitudinal axis AA, the plurality of longitudinally elongated walls 47 define an alignment plane for the laminated sheet, which is orthogonal to the sliding / conveying plane of the laminated sheet 100. Said alignment plane must be parallel to a plane orthogonal to the sheet or web of the multilayer composite paperboard 110, which plane passes along the leading edge 111 of the sheet or web of the multilayer composite paperboard 110.

[0043] according to Figure 8In the embodiment shown in , the second motorized conveyor unit B1 includes at least one second movable abutment element 46'. Each movable abutment element 46' also includes at least one abutment wall 47 extending in the longitudinal direction. Each movable abutment element 46' is arranged on the corresponding belt 42 so that the abutment wall 47 is arranged transversely to the extension of the belt 42, that is, transversely to the longitudinal axis coinciding with the forward feed direction DR. In this case, too, when the abutment elements 46' are aligned with each other along the longitudinal axis A'-A', the plurality of longitudinally extending walls 47 define an alignment plane for the laminate, which is orthogonal to the sliding / conveying plane of the laminate 100.

[0044] According to a particularly advantageous characteristic feature, each movable abutment element 46 ′ in each belt 42 is arranged equidistant from the first movable abutment element 46 relative to the circumferential extension of the belt 42. Thanks to this arrangement, during use, when the first set of movable abutment elements 46 passes below the sliding / conveying plane of the laminated sheets 100 after the belt 42 has rotated, having aligned a first laminated sheet 100, the second set of movable abutment elements 46 ′ moves upwards onto the sliding / conveying plane of the laminated sheets 100 in order to align the next laminated sheet 100.

[0045] Likewise, according to this embodiment, the second motorized conveyor unit B1 comprises a suction system provided with a suction port 97 arranged facing the belt 42 and connected to a suction duct 99. In this case, the belt 42 comprises through openings 43, i.e. holes, designed to attach the laminated sheet 100 by means of a suction airflow.

[0046] According to other embodiments, the alignment device 10 includes an optical measurement system S1 capable of detecting the transverse position of the sheets or webs of the laminated sheet 100 and the multi-layer composite paperboard 110. The alignment device 10 also includes a processing unit, such as an electronic board, connected to the optical measurement system S1 and the actuator 150. The processing unit is configured to receive and process data received from the optical measurement system S1 and operate the actuator 150 based on the processed data.

[0047] According to a further embodiment, the optical measuring system S1 is located directly above the belt 42 of the second motorized conveyor unit B1 .

[0048] According to a particularly advantageous characteristic feature, the inlet of the second motorized conveyor unit B1 is arranged at a distance from the outlet of the first conveyor unit B0 that is equal to the length of the laminated sheets to be joined and therefore must be variable according to the format.

[0049] The alignment device 10 comprises an acceleration unit R2 which is arranged adjacent to the second motorized conveyor unit B1. In the embodiment shown in the figures, the acceleration unit R2 is arranged above the motorized conveyor unit B1 and, in particular, in the end of the motorized conveyor unit B1 along the forward feed path of the laminated sheet 100 in the forward feed direction DR.

[0050] The acceleration unit R2 is configured to increase the conveying speed of the laminated sheet 100 and may include a plurality of acceleration rollers 70 connected to an independent actuator 78 via a shaft for rotation about its rotation axis. The acceleration unit R2 may also include a plurality of pressure wheels 72 arranged vertically above the acceleration rollers 70 and distributed transversely relative to the axis defined by the forward feed direction DR.

[0051] In other embodiments, the acceleration unit R1 comprises a single acceleration roller connected to a separate actuator.

[0052] The acceleration unit R2 also includes an actuator 76, which is directly connected to the pressure wheel 72 and is configured to shift the pressure wheel 72 from an operating position in which the pressure wheel 72 contacts the laminated sheet 100 and applies a thrust thereto to a stationary position in which the pressure wheel 72 does not contact the laminated sheet 100 during use.

[0053] according to Figure 9a 、 9b In one embodiment of the invention shown in Figures 1 and 9c, the alignment device 10 includes an actuator 150 connected to the second motorized conveyor unit B1, which is configured to, during use, move the motorized conveyor unit B1, and therefore the belt 42, transversely relative to a longitudinal axis coinciding with the forward feed direction DR of the laminated sheets. According to a particularly advantageous feature, the actuator can be an electric jack 150 fixed to a support structure 152 of the alignment device 10. As will be more clearly shown below, the electric jack 150 is particularly designed to move the second motorized conveyor unit B1, and therefore the belt 42, quickly, frequently, and with great precision. Obviously, different types of actuators 150 are conceivable, such as those operated by servo motors or electric pistons, or any other known type of actuator, as long as it is capable of moving the second motorized conveyor unit B1 quickly, frequently, and with great precision.

[0054] According to the embodiment shown, the second motorised conveyor unit B1 can be mounted on a secondary structure attached to the primary structure by means of one or more guides allowing the aforementioned lateral displacement of the second motorised conveyor unit B1 relative to a longitudinal axis coinciding with the forward feed direction DR of the laminated sheets.

[0055] The corrugated board laminating machine further comprises a laminating unit R3 for joining a laminated sheet to a sheet or web of multilayer composite board, which is arranged downstream of the second conveying unit B1 along the forward feed path of the laminated sheet 100 in the forward feed direction DR.

[0056] In the embodiment shown in the figure, the laminating unit R3 includes a pair of rollers 62, 64 arranged one above the other and at least one independent actuator 61. Each of the rollers 62, 64 has a rotation axis, and at least one of the two rollers (e.g., roller 64) is connected to the actuator 61 to rotate about its rotation axis and press the sheet or web of the laminated sheet 100 and the multi-layer composite paperboard 110 between the two rollers 62, 64 and help bond them together and transport them in the forward feed direction DR. Figure 3 In the embodiment shown, the roller 64 is configured as a return roller for a belt that moves a sheet or web of multi-layer composite paperboard 110. Figure 6 In the embodiment shown, the roller 62 is also connected to a separate actuator 63 .

[0057] According to other embodiments, the laminating unit R3 includes a roller and a mat.

[0058] according to Figure 10 In another embodiment shown, the alignment device 10 according to the present invention comprises, along the forward feeding path of the laminated sheet 100 in the forward feeding direction DR:

[0059] - a first motorized conveying unit B0 for conveying the laminated sheet 100;

[0060] - a second motorized conveyor unit B1 for aligning the laminated sheets 100 , arranged downstream of the first motorized conveyor unit B0 ;

[0061] - an acceleration unit R2 arranged close to the second motorized conveyor unit B1 ; and

[0062] A laminating unit R3 for joining laminated sheets to sheets or webs of multilayer composite paperboard, arranged downstream of the second conveying unit B1 .

[0063] The technical characteristics of the motorized conveying units B0, B1, the acceleration unit R2 and the laminating unit R3 are the same as described above and therefore are not repeated for the sake of brevity but are incorporated by reference.

[0064] According to these embodiments, the alignment device 10 includes a separate second acceleration unit R1 that is arranged between the first motorized conveyor unit B0 and the second motorized conveyor unit B1 along the forward feed path of the laminated sheet 100 in the longitudinal forward feed direction DR. The second acceleration unit R1 is configured to increase the conveying speed of the laminated sheet 100 from the first motorized conveyor unit B0 to the second motorized conveyor unit B1.

[0065] The second acceleration unit R1 includes a plurality of acceleration wheels 32 and an independent actuator 31. The acceleration wheels 32 can be engaged with a shaft 33 having a rotation axis and connected to the actuator 31 to rotate about its rotation axis and move the acceleration wheels 32.

[0066] In other embodiments, the second acceleration unit R1 comprises a single acceleration roller connected to a separate actuator.

[0067] According to further embodiments of the present invention, the second acceleration unit R1 further comprises a pressure system, such as a plurality of pressure rollers 34, which are arranged to be superimposed on the acceleration wheel or roller and are configured to increase the friction force applied by the acceleration wheel 32 to the laminated sheet 100. According to these embodiments, the second acceleration unit R1 further comprises an actuator 35, which is connected to the pressure rollers 34 to move the pressure rollers 34 from an operating position to a rest position during use, in which the pressure rollers 34 are in contact with the laminated sheet 100, facilitating the thrust provided by the acceleration wheel 32, and in which the pressure rollers 34 are not in contact with the laminated sheet 100.

[0068] According to other embodiments, the alignment device 10 along the forward feeding path of the laminated sheet 100 in the forward feeding direction DR comprises:

[0069] - a first motorized conveying unit B0 for conveying the laminated sheet 100;

[0070] - a second acceleration unit R1 arranged between the first motorized conveyor unit B0 and the second motorized conveyor unit B1;

[0071] - a second motorized conveyor unit B1 for aligning the laminated sheets 100 , arranged downstream of the first motorized conveyor unit B0 ;

[0072] - a first acceleration unit R2 arranged in the vicinity of the second motorized conveyor unit B1 ; and

[0073] A laminating unit R3 for joining laminated sheets to sheets or webs of multilayer composite paperboard, arranged downstream of the second conveying unit B1 .

[0074] The technical characteristics of the motorized conveying units B0, B1, the acceleration units R1, R2 and the laminating unit R3 are the same as described above and therefore will not be repeated for the sake of brevity but are incorporated by reference.

[0075] According to these embodiments, the alignment device 10 includes a third conveying unit B2 for aligning the laminated sheets 100 arranged between the motorized conveying unit B1 and the laminating unit R3 along a forward feeding path of the laminated sheets 100 in the forward feeding direction DR.

[0076] Special References Figure 11 and 12 The third conveyor unit B2 includes at least one pair of belts 52, a pair of shafts 55 on which the belts 52 are mounted, and an independent actuator 51. Each of the shafts 55 has an axis of rotation, and at least one of the shafts 55 is connected to the actuator 51 to rotate about its axis of rotation and move the at least one pair of belts 52, thereby allowing the laminated sheet 100 to be conveyed in the forward feed direction DR. Each belt 52 has a predetermined longitudinal circumferential extension and width, such that the sum of the widths of the belts 52 allows the formation of a sliding / conveying plane for the laminated sheet 100. The at least one pair of belts 52 is longitudinally staggered relative to the pair of belts 42 of the second motorized conveyor unit B1.

[0077] The third motorized conveyor unit B2 comprises five belts 52 mounted on shaft 55 and shaft 45 of the second motorized conveyor unit B1. The belts 52 are evenly distributed along the length of the shafts 45, 55 and are longitudinally staggered relative to the belts 42 of the second motorized conveyor unit B1.

[0078] In other embodiments, the number, width and distribution of the belts 52 may vary as long as the belts 42 can form a sliding / conveying plane for the laminated sheet 100. Figure 12 For example, it is conceivable that the number of belts 52 is equal to or greater than the number of belts 42 of the second motorized conveyor unit B1.

[0079] according to Figure 13 In another embodiment shown, the alignment device 10 includes, in the forward feeding direction DR, a forward feeding path of the laminated sheet 100:

[0080] - a first motorized conveying unit B0 for conveying the laminated sheet 100;

[0081] - a second motorized conveyor unit B1 for aligning the laminated sheets 100 , arranged downstream of the first motorized conveyor unit B0 ;

[0082] - an acceleration unit R2 arranged near the second motorized conveyor unit B1;

[0083] a third conveyor unit B2 for aligning the laminated sheets 100 , arranged between the motorized conveyor unit B1 and the laminating unit R3 ; and

[0084] A laminating unit R3 for joining laminated sheets to sheets or webs of multilayer composite paperboard, arranged downstream of the third conveying unit B2.

[0085] The technical characteristics of the motorized conveying units B0, B1, B2, the acceleration unit R2 and the laminating unit R3 are the same as described above and therefore are not repeated for the sake of brevity but are incorporated by reference.

[0086] The present invention also includes a method for aligning laminated sheets in a corrugated board laminator.

[0087] The corrugated board laminating machine according to the present invention comprises a laminated sheet magazine 1 or sheet feeder, a conveying area 2 for conveying laminated sheets in a forward feeding direction DR, an inlet 5 for a multi-layer composite board web moving in a longitudinal direction DR2, an alignment device 10 for aligning the laminated sheets 100, and a laminating unit R3 for joining the laminated sheets 100 to sheets of multi-layer composite board 110.

[0088] exist Figure 14 In the illustrated embodiment, the corrugated board laminator may further include a discard unit 219 , a longitudinal cutting or trimming unit 220 , a vinyl gluing unit 230 , and a transverse cutting unit 240 .

[0089] The method of aligning laminated sheets according to the present invention comprises a first step involving feeding the laminated sheets 100 from the laminated sheet magazine 1 to the motorized transport unit B1 at a first predetermined feeding speed V0 along a forward feeding path of the laminated sheets 100 in a forward feeding direction DR.

[0090] Specifically, the laminated sheets 100 stored in the laminated sheet magazine 1 are taken out and conveyed to the first motorized conveyor unit B0 and placed on the belt 22. The actuator rotates the pair of shafts 24 and 25, causing the belt 22 to move at a first predetermined speed V0. Thus, the laminated sheets 100 are advanced in the forward feed direction DR at the first predetermined speed V0 by the belt 22.

[0091] The method comprises a second step consisting in feeding the laminated sheet 100 against at least one movable abutment element 46, 46' engaged with the motorized conveyor unit B1 and arranged on a sliding / conveying plane, wherein said movable abutment element 46, 46' moves at a predetermined movement speed V1. The value of the movement speed V1 is less than the value of the first feeding speed V0.

[0092] Specifically, a pair of shafts 44, 45 on which the at least one pair of belts 42 are mounted are rotated by the independent actuator 41, so that the at least one pair of belts 42 and each movable abutment element 46, 46' engaged with the corresponding belt 42 are moved at the second predetermined moving speed V1. During this step, the laminated sheet 100 continues to advance at the first predetermined feeding speed V0.

[0093] Since the value of the feed speed V0 at which the laminated sheet 100 is conveyed is greater than the value of the moving speed V1 of the movable abutment elements 46 , 46 ′, the laminated sheet 100 abuts against each of the movable abutment elements 46 , 46 ′.

[0094] This arrangement prevents the laminated sheet 10 from undesirably rotating during its movement along the forward feed path in the forward feed direction DR, which rotation could result in incorrect alignment of the laminated sheet 100 with the sheet or web of the multilayer composite paperboard 110. In particular, the leading edge 101 of the laminated sheet 100 will be aligned with the alignment axis AA, A'-A' defined by the longitudinally extending walls of the movable abutment elements 46, 46' and, therefore, with the axis defined by the leading edge 111 of the sheet or web of the multilayer composite paperboard 110.

[0095] The second motorized conveyor unit B1 is activated and controlled to ensure a predetermined synchronization with the remaining conveyor units and the conveying of the laminated sheet 100. For example, when the laminated sheet 100 arrives at the second motorized conveyor unit B1, one of the two movable abutment elements 46, 46' arranged on each belt 42 is located facing the leading edge 101 of the laminated sheet 100. In addition, the rotation speed of the shaft 44 and the speed V1 of the belts must be such that a half-turn of each belt 42 is synchronized with the arrival of a new laminated sheet 100.

[0096] The method comprises a third step involving feeding the laminated sheet 100 from the motorized conveying unit B1 to the laminating unit R3 at a second predetermined feeding speed V2 in order to join the laminated sheet 100 to the multilayer composite paperboard sheet 110. The value of the speed V2 is greater than the value of the speed V1 and the value of the speed V0 and corresponds to the forward feeding speed V of the sheet or web of the multilayer composite paperboard 110. c The sheet is fed from the acceleration unit R2 to the lamination unit R3.

[0097] Specifically, the acceleration roller 70 of the acceleration unit R2 is rotated at the second predetermined forward feed speed V2 by the independent actuator 78 , and the pressure wheel 72 is displaced to the operating position in contact with the laminated sheet 100 .

[0098] At this time, the laminated sheet 100 is moved by the acceleration roller 70 and the pressure wheel 72 at a third predetermined speed V2, leaving the motorized conveying unit B1 until it reaches the laminating unit R3 along the forward feed path in the forward feed direction DR, which is configured to join the laminated sheet 100 to the multi-layer composite paperboard 110.

[0099] Then, at the forward feed speed V c The moving sheet or web of multi-layer composite paperboard 110 (whose value corresponds to the value of the second moving speed V2) is joined together with the previously aligned laminated sheet 100 to form a laminated corrugated paperboard.

[0100] According to a further embodiment, the method according to the invention comprises, after the above-mentioned second step, i.e. when the laminated sheet 100 is located on the second motorized conveyor unit B1, the step of moving the second motorized conveyor unit B1 transversely with respect to a longitudinal axis coinciding with the forward feed direction DR from a first initial position to a second position in which the side edge 103 of the laminated sheet 100 is aligned with the side edge 113 of a sheet or web of multilayer composite paperboard 110 passing simultaneously at a predetermined speed under the alignment device 10.

[0101] Once the laminated sheet leaves the second motorized conveyor unit B1 , the second motorized conveyor unit B1 moves again to the initial position in order to receive the next laminated sheet 100 .

[0102] According to another embodiment, before moving the second motorized conveyor unit B1, the optical measurement system S1 detects the position of the side edge 113 of the sheet or web of the multilayer composite paperboard 110 and the position of the side edge 103 of the laminated sheet 100, in order to quantify the necessary transverse shift of the second motorized conveyor unit B1 so that the laminated sheet 100 is transversely aligned with the sheet or web of the multilayer composite paperboard 110.

[0103] According to other embodiments, when the optical measuring system S1 is located directly above the belt 42 , direct feedback on the edge position is also provided during the displacement of the second motorized conveyor unit B1 .

[0104] Some embodiments include the step of attaching the laminated sheet 100 to the belt 42 of the second motorized conveyor unit B1 after the leading edge 101 of the laminated sheet 100 has been aligned with the alignment axis AA defined by the longitudinally elongated walls of the movable abutment elements 46, 46'. This step is particularly useful in embodiments in which the second motorized conveyor unit B1 is displaced transversely relative to a longitudinal axis coinciding with the forward feed direction DR, so as to allow the side edges 103 of the laminated sheet 100 to be aligned with the side edges 113 of the sheet or web of multilayer composite paperboard 110. By attaching the laminated sheet 100 to the belt 42, undesirable movement of the laminated sheet 100 due to displacement of the second motorized conveyor unit B1 can be prevented, thereby preventing misalignment.

[0105] In particular, once the leading edge 101 of the laminated sheet 100 is aligned with the alignment axis AA defined by the longitudinally elongated walls of the movable abutment elements 46, 46', the suction system is activated and air drawn through the suction duct 99 and the through openings 43 formed in the belt 42 allows the laminated sheet 100 to attach to the belt 42. Once the laminated sheet 100 reaches the acceleration unit R2, the first set of movable abutment elements 46 are moved below the sliding / conveying plane of the laminated sheet 100 and the leading edge 101 of the laminated sheet 100 is engaged by the pair of rollers 62, 64, and the suction system is deactivated to allow the acceleration unit R2 to feed the laminated sheet to the laminating unit R3.

[0106] The method for aligning laminated sheets according to the present invention can also be implemented in different embodiments of the alignment device described above.

[0107] In an embodiment comprising a separate second acceleration unit R1 arranged between the first motorized conveyor unit B0 and the second motorized conveyor unit B1, the laminated sheet 100 is in any case fed by the second acceleration unit R1 at a speed greater than the value of the second predetermined speed V1 at which the belt 42 and, therefore, the at least one movable abutment element 46, 46' are moved. The second acceleration unit can simply facilitate the movement of the laminated sheet 100 from the first motorized conveyor unit B0 to the second motorized conveyor unit B1. The fact that the speed set by the second acceleration unit R1 can be greater or less than the first predetermined speed V0 set by the first motorized conveyor unit B0 is absolutely irrelevant for the purposes of the present invention.

[0108] Similarly, in an embodiment of the alignment device comprising a third conveyor unit B2 arranged between the second motorized conveyor unit B1 and the laminating unit R3, the laminated sheet 100 is in any case fed by the third acceleration unit B2 at a speed having a value greater than the value of the second predetermined speed V1 at which the belt 42 and therefore at least one movable abutment element 46, 46' moves.

Claims

1. An alignment device for aligning laminated sheets in a corrugated board laminating machine, the alignment device comprising, in sequence along a conveying path of the laminated sheets (100) in a forward feed direction (DR): - a first conveying unit (B0) configured to convey the laminated sheet (100) at a conveying speed, - an accelerating roller (R2) configured to increase the conveying speed of the laminated sheet (100), - a second conveying unit (B1), Its characteristics are: The second conveying unit (B1) comprises at least one movable abutment element (46) arranged transversely to the forward feed direction (DR) of the laminated sheet and configured to align the laminated sheet (100).

2. The alignment device according to claim 1, characterized in that The second conveying unit (B1) comprises at least one pair of belts (42), a pair of shafts (44, 45) on which the at least one pair of belts (42) are mounted, and the second conveying unit (B1) comprises at least one movable abutment element (46) which engages with each of the belts (42).

3. Alignment device according to any one of the preceding claims, characterized in that Each belt (42) has a circumferential extension of a predetermined length and a predetermined width, so that the sum of the widths of the belts (42) forms a sliding / conveying plane for the laminated sheet (100).

4. The alignment device according to claim 2, characterized in that Each movable abutment element (46) comprises at least one abutment wall (47) extending in the longitudinal direction, a plurality of longitudinally extending walls (47) defining an alignment plane of the laminated sheet (100), said alignment plane being orthogonal to said sliding / conveying plane of said laminated sheet (100) when said abutment elements (46) are aligned with each other along the longitudinal axis (AA).

5. Alignment device according to any one of the preceding claims, characterized in that The second conveying unit (B1) comprises at least one second movable abutment element (46'), which is arranged transversely to the forward feed direction (DR) of the laminated sheet (100) and is configured to align the laminated sheet (100).

6. Alignment device according to any one of the preceding claims, characterized in that The acceleration unit (R2) includes at least one acceleration roller (70) connected to an independent actuator (78) to rotate about its own rotation axis and configured to increase the conveying speed of the laminated sheet (100).

7. The alignment device according to claim 6, characterized in that The acceleration unit (R2) further comprises a plurality of vertically arranged pressure wheels (72) vertically stacked above the acceleration roller (70) and distributed transversely with respect to an axis defined by the forward feed direction (DR).

8. Alignment device according to any one of the preceding claims, characterized in that The alignment device comprises an actuator (150) connected to the second conveyor unit (B1) and configured to move the second conveyor unit (B1) transversely relative to a longitudinal axis coinciding with a forward feed direction (DR) of the laminated sheet (100).

9. A method of aligning a laminate sheet with a multi-layer composite paperboard sheet in a corrugated paperboard laminating machine, comprising the steps of: (a) feeding the laminated sheet (100) from the laminated sheet magazine (1) to the conveying unit (B1) on the slide / conveying plane at a predetermined first feed speed (V0) along the conveying path of the laminated sheet (100) in a forward feed direction (DR); (b) feeding the laminated sheet (100) from the conveying unit (B1) at a second predetermined feeding speed (V2) to a laminating unit (R3) configured to join the laminated sheet (100) to a multi-layer composite paperboard sheet (110); It is characterized in that, between step (a) and step (b), the method comprises the following steps: (c) feeding the laminated sheet (100) against at least one movable abutment element (46, 46') engaged with the conveying unit (B1) and arranged on the sliding / conveying plane, wherein the movable abutment element (46, 46') moves at a predetermined movement speed (V1); The value of the movement speed (V1) is smaller than the values ​​of the first feed speed (V0) and the second feed speed (V2).

10. The method according to claim 9, characterized in that Between step (c) and step (b), the method comprises the following steps: (d) moving the conveying unit (B1) transversely relative to a longitudinal axis coinciding with the forward feed direction (DR) from a first initial position to a second position in which the side edge (103) of the laminated sheet (100) is aligned with the side edge (113) of the sheet or web of multilayer composite paperboard (110).

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