Machine for forming filter bags for infusion products
The machine addresses the challenge of safely and precisely changing tag strips by using a selector device and splicing units outside the operating zone, ensuring continuous production and reducing waste.
Patent Information
- Application Number
- JP2025517878
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-09-27
- Filing Date
- 2023-09-22
- Publication Date
- 2025-09-19
AI Technical Summary
Existing machines for forming filter bags for infusion products face challenges in safely and precisely changing tag strips due to the need for joining two different strips while the machine is running, leading to frequent shutdowns and waste due to imperfect joins.
A machine design with a selector device and splicing units outside the operating zone allows for synchronized replacement of tag strips without interrupting the machine's operation, using moving means to ensure continuous supply and precise splicing of tags onto the carousel.
Ensures precise and safe replacement of tag strips, reducing downtime and waste, and maintaining continuous production by performing splicing operations outside the protected operating zone.
Smart Images
Figure 2025531462000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a machine for manufacturing filter bags for infusion products such as tea.
[0002] The filter bag for infusion products such as tea comprises a mono- or bi-leaf filtering body containing a dose(s) of infusion product, the filtering body comprising a thread for connecting the filtering body with a tag. [Background technology]
[0003] There are prior art machines for forming these filter bags, which basically comprise a number of operating stations (arranged along a protected operating path) for forming the filter bags.
[0004] One of these stations is a rotating carousel with multiple grippers, on each of which is placed a filter bag containing a dose (or doses) of product and a tag connected to the thread, to which the stretch of the thread is applied during the stepwise rotational movement of the carousel.
[0005] In these machines, each component forming the filter bag (filter paper, product, thread and tag) has a corresponding supply station, including a station for supplying strips of tags, which is of particular interest in the present invention.
[0006] The supply station includes first and second reels each carrying first and second continuous strips of dags.
[0007] The first reel feeds the first strip of tags onto the wheel along a predetermined path to the carousel to form the filter bag, while the other reel waits to be used when the first strip of tags is nearly used up. The status of each reel, being nearly empty, is controlled by its respective sensor.
[0008] The second strip has an associated free end positioned adjacent to a zone of the predetermined path for supplying tags on the carousel. The free end of the waiting strip is provided with an adhesive bond.
[0009] In the same zone there are two rollers for transporting the first strip, one roller having a fixed axis of rotation and the other roller having a movable axis of rotation so that it can move towards and away from the one fixed roller.
[0010] When the first roll is exhausted, the unit is activated to move the second strip and connect it to the first strip by bilateral pressure, and the movable roller moves away from the fixed roller to allow the second strip to enter along a predetermined path.
[0011] With the machine running, and therefore with the first strip moving, the crimping must be done between the head of the first tag on the second strip and the tail of the tag on the nearly empty first strip, so that the two parts are flush with each other and match between the last tag (first strip) and the first tag (second strip).
[0012] Once the two strips are joined, the movable roller moves toward the fixed roller to continue feeding the second strip along the predetermined path.
[0013] At the same time, a cutting element separates the final stretch of the first strip of remaining dag upstream of the pair of rollers.
[0014] This type of operation must therefore be carried out in a very precise manner, since each tag, with its shape and printing on its surface, must be individually separated from the strip according to a predetermined feeding step and associated with a thread portion of the filter bag.
[0015] If the join between the two strips is not performed in the correct manner, i.e., not in a stepwise manner, the next subsequent tag fed to the carousel will be offset and therefore have an incorrect size and / or wording.
[0016] The presence of the tag on the carousel is controlled by a sensor located in close proximity to the carousel.
[0017] The photocell also detects whether the tag has the correct size and wording. If the photocell detects an incorrect tag, it begins transmitting a signal corresponding to a command to reject the respective filter bag. After a predetermined number or consecutive rejections, the machine is stopped for appropriate checking and retiming of the operating stations.
[0018] This type of prior art system therefore has the drawback that the safety of the system for changing the tag strips due to the emptying of the reel is limited, since it is necessary to join two different strips when the machine is running, i.e. when the operating strip is moving.
[0019] As previously mentioned, safety margins at the joints can cause frequent machine shutdowns. Summary of the Invention
[0020] SUMMARY OF THE INVENTION It is an object of the present invention to provide a machine for manufacturing filter bags for infusion products such as tea that overcomes the above-mentioned drawbacks of the prior art.
[0021] In particular, the object of the present invention is to provide a machine for producing filter bags for infusion products such as tea, which is able to ensure the replacement of the tag strips supplied with great precision and safety, without affecting the working parts of the machine.
[0022] A further object of the invention is to propose a method for changing the strips of tags, which is simple and safe, reduces the time taken to change the strips and also reduces the waste of strips from empty reels.
[0023] Said object is fully achieved by the machine for manufacturing filter bags for infusion products such as tea, and the method for changing tag strips, according to the present invention, as characterized in the appended claims. [Brief explanation of the drawings]
[0024] The principal features of the present invention will become more apparent from the following detailed description of a preferred, non-limiting embodiment, illustrated by way of example only in the accompanying drawings. [Figure 1] 1 shows part of a machine for forming filter bags for infusion products according to the invention; [Figure 2] 2 shows an enlarged detail of A shown in FIG. 1. [Figure 3] FIG. 2 shows a top view of an enlarged detail of B shown in FIG. 1. [Figure 4] 4A-4D show schematic top views of different configurations of the joining unit of FIG. 3; DETAILED DESCRIPTION OF THE INVENTION
[0025] With reference to the accompanying drawings, and in particular to Figure 1, a machine according to the present invention is generally designated 100 and is used to form filter bags S for infusion products.
[0026] In the example shown, the filter bags S may contain tea leaves and may each have at least one filtering chamber, a thread and a tag 4 .
[0027] This description shows only those parts of the machine 100 that are of particular interest.
[0028] The machine 100 comprises a carousel 1 which rotates in a stepped manner about an axis of rotation X (horizontal).
[0029] The carousel 1 has a number of grippers 2 arranged circumferentially (radially) and configured to hold respective filtering chambers with thread (applied during a series of steps at a previous operating station).
[0030] Each gripper 2 is configured to move, in stepwise rotations, each filtering chamber to a pick-up zone 3 (in particular to a single tag 4 to be joined to the thread).
[0031] The machine 100 also comprises a first reel 5 of a first continuous strip 6 (from which tags are to be cut) to be fed to the pick-up zone 3, and a second reel 8 of a second strip 9 (of tags to be cut) to be fed to the pick-up zone 3 as an alternative to the first strip 6.
[0032] The two reels 5 and 6 are rotatably keyed to the frame of the machine 100 about respective axes X5 and X8.
[0033] As shown, the machine 100 comprises a selector device 10 with a first channel 12 into which a first strip 6 arriving from a first reel 5 is engaged.
[0034] The selector device 10 comprises a second channel 13 into which a second strip 9 of tags arriving from a second reel 8 engages.
[0035] As also shown, the selector device 10 includes a shared outfeed 10 a in the pickup zone 3 .
[0036] As shown, the machine 100 also includes a first moving means 14 and a second moving means 15 arranged along the first channel 12 and the second channel 13, respectively, and configured to supply the first strip 6 and the second strip 9, respectively.
[0037] These first and second moving means 14, 15 are selectively actuated to alternately deliver the first strip 6 or the second strip 9 of tags.
[0038] These first and second moving means 14 and 15 are: the first strip 6 when it is detected that the second strip 9 is running out, or - selectively actuated to alternately supply the second strip 9 when it is detected that the first strip 6 is running out, to ensure continuity of operation;
[0039] As shown, the machine 100 also includes a tag cutting unit 11 located adjacent to the shared outfeed 10 a of the selector device 10 .
[0040] The cutting unit is configured to cut a single tag 4 at a time from the first strip 6 when the first strip 6 is supplied, or from the second strip 9 when the second strip 9 is supplied, so that the single tag 4 is associated with the thread of the filtering chamber that is brought to the pickup zone 3 by the gripper 2.
[0041] The machine 100 also comprises a first splicing unit 17 and a second splicing unit 18 for the first strip 6 and the second strip 9, respectively, arranged between the corresponding first reel 5 and second reel 8 and the corresponding first moving means 14 and second moving means 15 along the corresponding first path P6 and second path P9 of the first strip 6 and the second strip 9.
[0042] The first splicing unit 17 is configured to splice the final end of the first strip 6 with the initial end of a new first strip coming from a new first reel when no first strip 6 is supplied by the first moving means 14.
[0043] The second splicing unit 18 is designed to splice the final end of the second strip 9 with the initial end of a new second strip coming from a new second reel when no second strip 9 is supplied by the second moving means 15.
[0044] As shown, the machine 100 also includes a partition wall 26 positioned to separate the first splice unit 17 and the second splice unit 18 from the carousel 1 .
[0045] In light of this, the partition wall 26 is provided with a first slit 26a and a second slit 26b to allow the first strip 6 and the second strip 9 to pass through, respectively, without obstructing the above-mentioned first path P6 and second path P9.
[0046] It should be noted that the partition wall 26 also separates the first and second splice units 17, 18 from the selector device 10 (as clearly shown in Figure 1).
[0047] With this in mind, the partition wall 26 is part of a protective guard 30 that surrounds the carousel 1 and subsequent stations of the machine 100 designed to form filter bags S.
[0048] It should be noted that the partition wall 26 is arranged in a plane parallel to the axis of rotation X of the carousel 1 .
[0049] In other words, the machine 100 comprises two zones separated by the guard 30, the first zone being open and containing the reels supplying the materials for forming the filter bags (filter paper, tags, bonding threads, distribution of the product to be packaged), while the second zone, protected by the guard, comprises all the stations for forming the filter bags.
[0050] It should be noted that, since the splicing unit is located outside the protective guard of the machine, all operations necessary for changing the empty reel and splicing the new strip with the remaining strip portion are carried out in a zone outside the operating zone protected by the guard and therefore do not affect the normal operation of the bag forming station, which can continue its operations safely.
[0051] It should be noted that the first moving means 14 and the second moving means 15 are connected to a shared control unit 7 (which is connected to the overall control unit of the machine), which is configured to selectively enable the first strip 6 to be synchronously fed to the cutting unit 11 with stepwise movements while the second strip 9 remains stationary, or the first strip 6 of the dog remains stationary while the second strip 9 is synchronously fed to the cutting unit 11 with stepwise movements.
[0052] As shown in detail in Figure 2, the selector device 10 comprises a wedge-shaped element 16 having an apex adjacent to the cutting unit 11 (the apex defining a shared outfeed 10a for both strips of tags when fed).
[0053] The body 16 has two opposing surfaces with a first channel 12 and a second channel 13 formed therein, respectively.
[0054] Each surface of the wedge-shaped body 16 is covered by a respective cover guard 16a and 16b, each guard 16a and 16b having a larger extension than the extension of the associated surface of the wedge-shaped body 15 so as to protrude relative to the apex of the wedge and defining a slit defining a shared outfeed 10a to allow controlled outfeeding of tags towards the pickup zone 3.
[0055] The first moving means 14 and the second moving means 15 each comprise a pair of rollers 14a and 15a facing each other for the first strip 6 and the second strip 9, respectively.
[0056] Each pair of rollers 14a and 15a is provided with a corresponding drive unit connected to the control unit 7 so as to synchronously feed the first strip of tags 6 into the pick-up zone 3 while keeping the second strip of tags 9 waiting and stationary, and when the first reel 5 is used up, to pull out the remaining part of the first strip of tags 6 along the first path P6 while simultaneously feeding the second strip 9 into the pick-up zone in a synchronous manner, thereby locking the first strip of tags 6 away from the pick-up zone 3 and vice versa.
[0057] As shown in Figures 1, 3 and 4, the machine 100 comprises the aforementioned first and second splicing units 17, 18 for the first and second strips 6, 9 of the tag, respectively.
[0058] The first connection unit 17 and the second connection unit 18 are arranged along the corresponding first path P6 or second path P9 of the strips 6, 9 between the respective first reel 5 and second reel 8 and the respective first moving means 14 and second moving means 15.
[0059] It should be noted that each of the first splicing unit 17 and the second splicing unit 18 is configured to align, in a synchronized manner, the final end of the corresponding first strip 6 and second strip 9 with the initial end of the new first and second strips from the new first and second reels when the corresponding strip 6 or 9 remains stationary by the respective moving means 14 and 15.
[0060] In other words, while one of the strips 6 or 9 is being fed to the carousel 1, the other strip 9 or 6 is stationary and may be replaced and aligned in a synchronized manner with a new strip, which will be spliced onto the part of the old strip still present along path P9 or P6.
[0061] With this in mind, as shown in Figures 3 and 4, each of the first joining unit 17 and the second joining unit 18 includes a support plate 19 arranged along a first path P6 and a second path P9 along which the first strip 6 and the second strip 9 slide, respectively.
[0062] Each support plate 19 has at least one visual reference RV1 which can be aligned with a visual reference RV2 printed on the strips 6, 9 to enable accurate splicing (synchronizing the expiring strip that is no longer being fed into the pick-up zone 3 with the new strip).
[0063] It should be noted that each support plate 19 is connected to a first locking lever 20 configured to fix the non-advancing (running out) first strip 6 or second strip 9 in a predetermined position on the support plate 19, and a second locking lever 21 configured to fix a new strip in a predetermined position on the support plate 19.
[0064] The support plate 19 also includes a grooved track 22 that is disposed between the first locking lever 20 and the second locking lever 21 and that is configured to allow a web cutting element 23 (e.g., a slidable blade) to engage therewith.
[0065] Further, the support plate 19 is provided with a support lever 24 which is configured to be positioned adjacent to the grooved track 22 so as to allow the web cutting element 23 to slide along the grooved track 22 while resting on the support lever 24.
[0066] In other words, the new strip (see also Figure 4) - locking the end of the nearly empty reel with the first lever 20 in a synchronized manner (i.e. with the visual references RV1 and RV2 aligned), - cutting the connection between the empty reel and the last remaining part along path P6 or P9 with the web cutting element 23, with the cutting edge in the grooved track 22; -Replace the empty reel with a new one and unwind the new strip along the path, - positioning and locking the new strip on the plate 19 in a synchronized manner (i.e. with the visual references RV1 and RV2 aligned) with the second lever 21; - cutting a part of the new strip again in the web cutting unit 23 so that the cutting edge is in the grooved track 22 and in front contact with the edge of the final part, - It is joined to the last part of the finished strip by joining the two front contacting edges of the last part and the new strip with a joining web 25 (adhesive).
[0067] The present invention provides a method for selectively feeding strips of tags 4 into a machine 100 for forming filter bags S for infusion products such as tea.
[0068] The method comprises the following steps: - providing a carousel 1 rotating in stages about an axis of rotation X, said carousel 1 having a plurality of grippers 2 arranged circumferentially and configured to hold a respective filtering chamber provided with a thread, each gripper 2 moving a filtering chamber to a pick-up zone 3; - providing a first reel 5 of a first strip 6; - providing a second reel 8 of a second strip 9; - stopping the supply of the first strip 6 by the first moving means 14 when the first strip 6 is almost used up, and, in synchronism with this step, - actuating the supply of the second strip 9 by means of the second movement means 15; - cutting a single tag 4 at a time from the first strip 6 when the first strip 6 is provided, or from the second strip 9 when the second strip 9 is provided, so that the single tag 4 is associated with the thread of the filtering chamber in the pick-up zone 3, the cutting being carried out by a tag cutting unit 11 arranged close to the pick-up zone 3; - preparing a first splicing unit 17 and a second splicing unit 18 for the first strip 6 and the second strip 9, respectively, arranged between the corresponding first reel 5 and second reel 8 and the corresponding first moving means 14 and second moving means 15 along the corresponding first path P6 and second path P9 of the first strip 6 and the second strip 9, wherein the first splicing unit 17 is configured to splice the final end of the first strip 6 with the initial end of a new first strip coming from a new first reel when the first strip 6 is not being fed by the first moving means 14, and the second splicing unit 18 is configured to splice the final end of the second strip 9 with the initial end of a new second strip coming from a new second reel when the second strip 9 is not being fed by the second moving means 15; - preparing a partition wall 26 separating the first joining unit 17 and the second joining unit 18 from the carousel 1, the partition wall 26 being provided with a first slit 26a and a second slit 26b to allow the first strip 6 and the second strip 9 to pass through, respectively, without interfering with the first path P6 and the second path P9.
[0069] Preferably, the step of stopping the first strip 6 also includes the step of moving the first strip 6 away from the tag cutting unit 11, ie, pulling it out.
[0070] The method also comprises, after stopping the first strip 6, keeping the first reel 5 of the first strip 6 stationary, the following steps: - separating the last part of the first strip 6 from the first reel 5 that is running out; - disassembling a first empty reel 5; - assembling a new first reel of a new first strip; - locking the final section to the support plate 19 using the first locking lever 20; - placing the initial part of the new first strip on the support plate 19 superimposed on the final part, so that the indicator elements RV2 of the final and initial parts respectively coincide with the visual references RV1 present on the support plate 19; - locking the initial part on the support plate 19 by means of the second locking lever 21; - cutting the final part and the initial part; - applying a joining web 25 for joining the final and initial parts; - Releasing the final and initial parts from the support plate 19 and unlocking the first and second locking levers 20 and 21 respectively so that a new first strip 6 can be fed to the tag cutting unit 11.
Claims
1. A machine for forming filter bags (S) for infusion products, comprising: a carousel (1) rotating in stages about an axis of rotation (X), the carousel (1) having a plurality of grippers (2) arranged circumferentially and configured to hold each filtering chamber provided with a thread, each gripper (2) being configured to move said filtering chamber to a pick-up zone (3); - a first reel (5) of a first strip (6) and a second reel (8) of a second strip (9), moreover, a selector device (10) comprising a first channel (12) for engaging the first strip (6) arriving from the first reel (5) and a second channel (13) for engaging the second strip (9) arriving from the second reel (8), said selector device (10) having a shared outfeed (10a) in said pick-up zone (3); - first and second moving means (14) and (15) arranged along said first and second channels (12) and (13), respectively, and configured to feed said first and second strips (6) and (9), said first and second moving means (14) and (15) comprising: - the first strip (6) when it is detected that the second strip (9) is running out, or - first and second moving means (14) and (15) selectively operated to alternately supply the second strip (9) when it is detected that the first strip (6) is running out, so as to ensure continuity of operation; a unit (11) for cutting tags, arranged close to the shared outfeed (10a) of the selector device (10), configured to cut a single tag (4) at a time from the first strip (6) when the first strip (6) is fed, or from the second strip (9) when the second strip (9) is fed, so that the single tag (4) is associated with the thread of the filtering chamber brought by the gripper (2) to the pick-up zone (3); - a first splicing unit (17) and a second splicing unit (18) for the first strip (6) and the second strip (9), respectively, arranged along the corresponding first path (P6) and second path (P9) of the first strip (5) and the second strip (8) between the corresponding first reel (5) and second reel (8) and the corresponding first moving means (14) and second moving means (15), each first splicing unit (17) being configured to move the first strip (6) along the corresponding first path (P6) and second path (P9) of the first strip (5) and the second strip (8), respectively; a first splicing unit (17) and a second splicing unit (18) configured to splice a final end of the first strip (6) with an initial end of a new first strip coming from a new first reel when the first strip (6) is not being supplied by a first moving means (14), and each second splicing unit (18) configured to splice a final end of the second strip (9) with an initial end of a new second strip coming from a new second reel when the second strip (9) is not being supplied by the second moving means (15); a partition wall (26) arranged to separate the first splicing unit (17) and the second splicing unit (18) from the carousel (1), the partition wall (26) being provided with a first slit (26a) and a second slit (26b) to allow the first strip (6) and the second strip (9), respectively, to pass through without interfering with the first path (P6) and the second path (P9).
2. 2. The machine of claim 1, wherein the partition wall (26) also separates the first splicing unit (17) and the second splicing unit (18) from the selector device (10).
3. 3. A machine according to claim 1 or 2, wherein the partition wall (26) is part of a protective guard (30) surrounding the carousel (1).
4. 4. A machine according to any one of claims 1 to 3, wherein the partition wall (26) is arranged in a plane parallel to the axis of rotation (X) of the carousel (1).
5. 5. The machine according to any one of claims 1 to 4, wherein the first and second movement means (14) and (15) are connected to a shared control unit (7) configured to selectively enable synchronous feeding of the first strip (6) to the tag cutting unit (11) with stepwise movement while the second strip (9) remains stationary, or keeping the first strip (6) stationary while simultaneously feeding the second strip (9) to the tag cutting unit (11) with stepwise movement.
6. 6. A machine according to any one of claims 1 to 5, wherein the selector device (10) comprises a body (16) having a wedge shape with an apex adjacent to the tag cutting unit (11), and the first and second channels (12, 13) are formed in two opposite surfaces of the body (16), respectively.
7. 7. A machine according to any one of claims 1 to 6, wherein each of the first splicing unit (17) and the second splicing unit (18) comprises a respective support plate (19) arranged along the first path (P6) and the second path (P9), respectively, along which the first strip (6) and the second strip (9) slide, respectively.
8. 8. A machine as claimed in claim 7, wherein each support plate (19) has at least one visual reference (RV1) which can be aligned with a visual reference (RV2) printed on said strips (6, 9) to allow accurate joining.
9. 9. A machine according to claim 7 or 8, wherein each support plate (19) is associated with a first locking lever (20) configured to lock the non-advancing first or second strip (6, 9) in place on said support plate (19), and a second locking lever (21) configured to lock the new strip in place on said support plate (19).
10. 10. The machine of claim 9, wherein each support plate (19) comprises a grooved track (22) arranged between the first locking lever (20) and the second locking lever (21) and configured to receive a web cutting element (23) therein.
11. 11. The machine according to claim 10, wherein the support plate (19) also comprises a support lever (24) configured to be placed in the grooved track (22) and allowing the web cutting element (23) to slide along the grooved track (22) while resting on the support lever (24).
12. 12. A machine according to any one of claims 1 to 11, wherein the first and second moving means (14, 15) each comprise a pair of opposing rollers (14a, 15a).
13. 13. A machine according to any one of claims 1 to 12, wherein the first reel (5) and the second reel (8) rotate on respective axes of rotation (X5, X8) parallel to the axis of rotation (X) of the carousel (1).
14. 14. A machine according to any one of claims 1 to 13, wherein the first reel (5), the second reel (6) and the carousel (1) are arranged in vertical, coplanar and continuous planes.
15. 1. A method for replacing a strip of tags during the formation of a filter bag (S) for an infusion product, comprising: - providing a carousel (1) rotating in stages about an axis of rotation (X), said carousel (1) having a plurality of grippers (2) arranged circumferentially and configured to hold each filtering chamber provided with a thread, each gripper (2) moving said filtering chamber to a pick-up zone (3); - providing a first reel (5) of a first strip (6); - providing a second reel (8) of a second strip (9); - by means of first moving means (14) stopping the supply of said first strip (6) when it is nearly used up, and, in synchronism with said step, - actuating the supply of said second strip (9) by means of second movement means (15); - cutting a single tag (4) at a time from the first strip (6) when the first strip (6) is supplied, or from the second strip (9) when the second strip (9) is supplied, so that the single tag (4) is associated with the thread of the filtering chamber in the pick-up zone (3), the cutting being carried out by a tag cutting unit (11) arranged close to the pick-up zone (3); - providing first splicing units (17) and second splicing units (18) for the first strip (6) and the second strip (9), respectively, arranged between the corresponding first reels (5) and second reels (8) and the corresponding first moving means (14) and second moving means (15) along the corresponding first paths (P6) and second paths (P9) of the first strip (5) and second strip (8), wherein each first splicing unit (17) comprises: each second splicing unit (18) is configured to splice a final end of the first strip (6) with an initial end of a new first strip coming from a new first reel when the first strip (6) is not supplied by the first moving means (14), and each second splicing unit (18) is configured to splice a final end of the second strip (9) with an initial end of a new second strip coming from a new second reel when the second strip (9) is not supplied by the second moving means (15); - providing a partition wall (26) separating the first splicing unit (17) and the second splicing unit (18) from the carousel (1), the partition wall (26) being provided with a first slit (26a) and a second slit (26b) to allow the first strip (6) and the second strip (9), respectively, to pass through without interfering with the first path (P6) and the second path (P9).
16. 16. The method according to claim 15, wherein the step of stopping the first strip (6) also comprises the step of moving or withdrawing the first strip (6) away from the tag cutting unit (11).
17. After stopping said first strip (6), while keeping said first reel (5) of said first strip (6) stationary, the method comprises the steps of: - separating the last part of said first strip (6) from said first reel (5) that is running out; - disassembling said first empty reel (5); - assembling a new first reel of a new first strip; - locking said final part onto the support plate (19) using the first locking lever (20); - placing the initial part of the new first strip on the support plate (19) superimposed on the final part, in such a way that the indicator elements (RV2) of the final part and of the initial part coincide with the visual references RV1 present on the support plate (19); - locking said initial part on said support plate (19) by means of a second locking lever (21); - cutting said final part and said initial part; - applying a joining web (25) to join said final part and said initial part; - releasing the final and initial portions from the support plate (19) and unlocking the first (20) and second (21) locking levers, respectively, so that the new first strip (6) can be fed to the tag cutting unit (11).