A core winder for forming a log core, a method for forming the core, and a tissue paper log comprising the core.

Abstract

This core winder provides a compact core that can be easily extracted while keeping the overall volume of the log compact. [Solution] The core winder (100) comprises: a dispensing station (10) configured to dispense two or more reels (11) of corrugated cardboard strips (201, 202); a forming station (20) located downstream of the dispensing station (10) and configured to overlap at least the upper strip (201) and lower strip (202) dispensed from the reels (11) and wind them spirally, joining them together to form a tube; and a cutting station (30) located downstream of the forming station (20) and configured to cut the forming tube to obtain a core.

Description

Technical Field

[0001] The present invention relates to a core winder for forming a core for a tissue paper log. The present invention further relates to a method of forming such a core, and a tissue paper log comprising said core.

[0002] The present invention is usefully applied in the field of so-called "tissue" type paper, that is, paper for products such as toilet paper, kitchen paper, etc., and particularly relates to "coreless" applications where the finished paper roll lacks a core.

Background Art

[0003] It is known to manufacture a laminated tissue paper roll consisting of a plurality of plies, generally two or three plies, from a paper material reel, a so-called log, which has the same diameter as the final paper roll but a longer length. Such a log is obtained by winding paper plies that have been previously subjected to various processing steps onto a cardboard core generally formed in the shape of a tubular element by a rewinding machine.

[0004] To form a paper roll for the end use, this log is cut into a plurality of units, and single paper rolls of shorter length are manufactured.

[0005] In so-called "coreless" roll applications without a core, the paper is wound in layers to form a roll. One of the known possible solutions is to manufacture a log with a core, where the core performs a structural support function during the winding process, and then remove the core before cutting the log into single rolls.

[0006] The process of extracting a conventional cardboard core from a log is known to be an important process because the core itself or the wound paper is often damaged. In particular, the innermost paper spiral connected to the core is deformed or torn.

[0007] To overcome these problems, Patent Document EP2711320B1 discloses a reel having a deformable plastic core, which is extracted by deforming it axially to reduce its diameter.

[0008] A disadvantage is that the method described in the document is limited to core materials and requires that certain mechanical property requirements be met for the material to be elastically deformable and reusable, such as a tensile yield strength ratio of greater than 2%.

[0009] Furthermore, the described method requires manufacturing a core longer than the length of the wound paper roll in order to grip and deform it axially for extraction. A disadvantage is that this type of log is bulkier than conventional logs where the core is the same length as the paper roll.

[0010] Disadvantages include the fact that plastic cores are more expensive than those made from cardboard, and they must be discarded if damaged. [Overview of the Initiative] [Problems that the invention aims to solve]

[0011] The fundamental problem of this invention is to provide a core winder that can form easily extractable cores while keeping the overall volume of the log compact.

[0012] A further object of the present invention is to provide a method for manufacturing such a core, and a tissue paper log comprising such a core. [Means for solving the problem]

[0013] The problems listed above, as well as the objectives mentioned and other objectives that will become clearer below, are achieved by the core winder according to claim 1, the method for forming a core according to claim 6, and the tissue paper log comprising the core according to claim 11.

[0014] Other features are described in the dependent claims.

[0015] In the following, with reference to the accompanying drawings, further features and advantages of a core winder, a method for forming a core, and a tissue paper log comprising the core will be described in an illustrative and non-limiting manner as preferred but non-limiting embodiments of the present invention. [Brief explanation of the drawing]

[0016] [Figure 1] A side perspective view of a core winder according to a preferred embodiment of the present invention is shown. [Figure 2] Figure 1 shows a detailed enlarged view of the core winder. [Figure 3] Another lateral perspective view of the core winder shown in Figure 1 is presented. [Figure 4] Figures 1 and 3 show a side perspective view of the corrugated cardboard tube being formed by the core winder. [Figure 5] A side view of a tissue paper log according to the present invention is shown. [Modes for carrying out the invention]

[0017] The core winder indicated by reference numeral 100 will be described below with reference to the attached drawings.

[0018] The core winder 100 is configured to form a core 200 for a tissue paper log 300 from corrugated cardboard strips 201 and 202.

[0019] According to the present invention, the core winder 100 comprises a dispensing station 10 configured to dispense two or more reels 11, 12 of corrugated cardboard strips 201, 202. In the example shown in the drawings, two reels 11, 12 are dispensed simultaneously. Thus, the core 200 is formed by two corrugated cardboard strips 201, 202 that are formed overlapping each other, in particular the upper strip 201 and the lower strip 202.

[0020] The core winder 100 includes a forming station 20 downstream of the payout station 10.

[0021] The forming station 20 is configured to wind at least an upper strip 201 and a lower strip 202 being fed out from the reels 11, 12 on top of each other in a spiral manner and join them to form a tube 203.

[0022] The core winder 100 includes a cutting station 30 downstream of the forming station 20.

[0023] The cutting station 30 is configured to cut the formed tube 203 to obtain a core 200.

[0024] According to the present invention, the core winder 100 is characterized by including a supply assembly 40 for an adhesive film 41. The supply assembly 40 is configured to pay out the adhesive film 41 that can be connected to the upper strip 201, thereby obtaining a core 200 at least partially covered with the adhesive film 41.

[0025] The supply assembly is preferably configured to directly connect the adhesive film 41 to the upper strip 201 at a low temperature.

[0026] The adhesive film 41 has an adhesive surface and a non - adhesive surface. The adhesive surface is intended to contact the upper strip 201, while the non - adhesive surface is preferably intended to directly contact a tissue paper wound onto the core 200 during the rewinding process.

[0027] Preferably, the entire adhesive surface is covered with an adhesive.

[0028] In particular, after being connected to the upper strip 201 at the adhesive surface, the adhesive film 41 can remain fixed to the upper strip 201.

[0029] In particular, the term "connected" means that one end edge of the adhesive film 41 is attached to the upper strip 201 at one point. In other words, at least one free end of the adhesive film 41 is fixed to the upper strip 201 at at least one point.

[0030] An advantage is that when the molding station 20 winds the strips 201 and 202 together, the adhesive film 41 that was previously attached to the upper strip 201 is also attached to the upper strip 201 at the same time, so that the upper strip 201 is covered at least partially with the adhesive film 41.

[0031] The adhesive film 41 makes the outer surface of the core 200 slippery.

[0032] Therefore, because it is covered with the adhesive film 41, the core 200 is more easily separable from the paper ply and thus extractable compared to known ones.

[0033] Preferably, the adhesive film 41 is a plastic film.

[0034] The supply assembly 40 is configured to feed out the adhesive film 41 at the same time as the reels 11 and 12 are fed out.

[0035] According to one embodiment, the adhesive film 41 can be manually connected to the upper strip 201 by an operator. Alternatively, the supply assembly 40 may include an arm or other element configured to connect the adhesive film 41 to the upper strip 201.

[0036] According to the first preferred embodiment, the adhesive film 41 is connected to the upper strip 41 at the molding station 20.

[0037] Preferably, the supply assembly 40 is located at the dispensing station 10, which is upstream of the molding station 20.

[0038] In other words, preferably, at the start of the process, the adhesive film 41 is supplied and connected to the upper strip 201, that is, at least the free end of the adhesive film 41 is fixed to the upper strip 201 at at least one point before the strips 201 and 202 are wound and joined at the forming station 20. In this way, the adhesive film 41 connected to the upper strip 201 at the forming station 20 at the start of the process adheres to the upper strip 201 at each point as the strips 201 and 202 are wound up when forming the tube 203.

[0039] According to the second embodiment, which is an alternative to the first embodiment, the adhesive film 41 can also be connected to and applied to the strip 201 between the molding station 20 and the cutting station 30.

[0040] For example, the supply assembly 40 can be located downstream of the molding station 20 and upstream of the cutting station 30.

[0041] Preferably, the supply assembly 40 includes a spindle 42 that engages with a roll 41' of adhesive film 41 and is configured to feed out the roll 41' while the feeding station 10 feeds out reels 11, 12.

[0042] The spindle 42 is, for example, an expandable type.

[0043] Preferably, the supply assembly 40 further includes a brake 43 configured to apply tension to the adhesive film 41 of the unwound roll 41'.

[0044] More preferably, the core winder 100 includes a control unit 44 that is in signal communication with the brake 43. The control unit 44 is configured in particular to adjust the braking action of the brake 43 as a function of the feed rate.

[0045] More preferably, the supply assembly 40 is integrated with the spindle 42 and includes a disc 45 connected to a brake 23. The brake 43 is configured to more or less brake the disc 45 in particular to adjust the tension of the adhesive film 41 being fed out, which depends on the type of corrugated cardboard of the strips 201, 202 on the reels 11, 12 being fed out. In fact, the feeding speed of the reels 11, 12 depends on the type of corrugated cardboard.

[0046] Preferably, the brake 43 includes a pneumatic or electro-pneumatic caliper configured to act on the disc 45.

[0047] Preferably, the core winder 100 includes a position sensor (not shown in the accompanying drawings) configured to detect interruptions in the unwound adhesive film 41.

[0048] The position sensor is preferably arranged in a signal communication state with the control unit 44.

[0049] In particular, the control unit 44 is configured to stop the unwinding of the reels 11 and 12, the unwinding of the adhesive film 41, the winding of the tube 203, and the cutting of the tube 203 when an interruption in the unwinding of the adhesive film 41 is detected, for example, due to a break.

[0050] The present invention is applicable to a known type of core winder 100 by incorporating a supply assembly 40 for the adhesive film 41 and appropriately configuring a control unit 44.

[0051] Therefore, the feeding station 10, the forming station 20, and the cutting station 30 are preferably of a known type.

[0052] Preferably, the feeding station 10 comprises two or more feeding rollers 13, 14, each configured to house and feed out reels 11, 12.

[0053] The supply assembly 40 is preferably mounted downstream of the feed rollers 13 and 14.

[0054] Preferably, the feeding station 10 further includes switching rollers 15, 16 for each feeding roller 13, 14. The switching rollers 15, 16 intervene by switching positions with the feeding rollers 13, 14 when the reels 11, 12 on the feeding rollers 13, 14 are finished.

[0055] More preferably, the dispensing station 10 includes an oil dispenser 17 configured to apply oil to the underside of the lower strip 202 of the first reel 11 being dispensed from each dispensing roller 13.

[0056] More preferably, the dispensing station 10 includes an adhesive dispenser 18 configured to apply adhesive to the underside of the upper strip 201 of the second reel 12 being dispensed from each dispensing roller 14. In this way, the upper strip 201 can be joined to the lower strip 202 when forming the pipe 203.

[0057] The oil applicator 17 and adhesive applicator 18 are known, as are the replacement rollers 15 and 16.

[0058] The molding station 20 preferably comprises a known support spindle 21 and belt 22.

[0059] Preferably, the core winder 100 also includes a transport station 50 interposed between the forming station 20 and the cutting station 30. The transport station 50 is configured to dry the adhesive and stabilize the formed tube 203 as it is transported from the forming station 20 to the cutting station 30.

[0060] According to the second embodiment, the supply assembly 40 can be placed at any position within the transport station 50.

[0061] Preferably, the adhesive film 41 is an adhesive tape, and preferably has a polymer support, such as PE, PP, or PVC.

[0062] An advantage is that the adhesive film 41 is already available in the form of a roll with the adhesive already applied, and therefore there is no need to form a roll of adhesive film 41 or to provide an adhesive assembly for applying the adhesive to the non-adhesive film. This significantly simplifies both the structure of the core winder 100 and the process of forming the core 200.

[0063] Another part of the present invention is a method for forming a core 200 for tissue paper logs from corrugated cardboard strips 201, 202.

[0064] The process according to the present invention includes the step of unwinding two or more reels 11, 12 of corrugated cardboard strips 201, 202.

[0065] The process also includes overlapping at least the upper strip 201 and the lower strip 202 unwound from the reels 11 and 12, winding them spirally, and joining them to form a tube 203.

[0066] The process further includes cutting the formed tube 203 to obtain a core 200.

[0067] According to the present invention, the process further includes unwinding an adhesive film 41 that can be connected to the upper strip 201, thereby obtaining a core 200 that is at least partially covered with the adhesive film 41.

[0068] This process is preferably carried out by the core winder 100 described above.

[0069] Preferably, the step of unwinding the adhesive film 41 is performed simultaneously with the step of unwinding two or more reels 11, 12.

[0070] Preferably, the process further includes connecting the adhesive film 41 to the upper strip 201. The process of connecting the adhesive film 41 includes attaching the adhesive surface of the adhesive film 41 to the upper strip 201. Preferably, the adhesive surface of the adhesive film 41 is attached directly to the upper strip 201.

[0071] An advantage is that, during the winding process, the adhesive film 41 that was previously attached to the upper strip 201 also adheres to the upper strip 201, thereby covering the upper strip 201 at least partially with the adhesive film 41.

[0072] Preferably, the process of unwinding the adhesive film 41, the process of joining the adhesive film 41, and the winding process are carried out at a low temperature.

[0073] According to one embodiment, the connection process is preferably performed manually by an operator at the cutting station 30.

[0074] Preferably, the connection step is performed before the cutting step.

[0075] According to the first preferred embodiment, the connection step is performed before the winding step.

[0076] Alternatively, according to the second embodiment, the connection step may be performed after the winding step and in any case before the cutting step.

[0077] Preferably, the adhesive film 41 is connected to the upper strip 201 while the machine is stopped, after a sufficient amount of adhesive film and strips 201 and 202 have been unwound to reach the cutting station 30. Then, the core winder 30 is started, and the unwound adhesive film 41 and reels 11 and 12 continues, while the winding of strips 201 and 202 is also started to form a tube 203, which is then cut when it reaches a predetermined length.

[0078] Preferably, the step further includes a step of braking the unwinding of the roll 41' of the adhesive film 41 in order to apply tension to the adhesive film 41.

[0079] More preferably, the step includes stopping the supply assembly 40 if an interruption in the unwound adhesive film 41 is detected. The step also includes stopping the unwound of the reels 11, 12, the winding of the strips 201, 202, and the cutting of the formed tube 203.

[0080] Preferably, the process further includes applying oil to the underside of the lower strip 202 of the first reel 11 that is fed out from each feed roller 13.

[0081] Preferably, the process further includes applying adhesive to the underside of the upper strip 201 of the second reel 12 that is fed out from each feed roller 14.

[0082] The steps of applying oil and applying adhesive are preferably carried out simultaneously before the winding step, according to known embodiments.

[0083] Another part of the present invention is a tissue paper log 300, which forms a precursor for one or more coreless tissue paper rolls.

[0084] The log 300 comprises a core 200, which includes at least an upper strip 201 and a lower strip 202 made of corrugated cardboard, which are overlapped and spirally wound together. The core 200 further includes an adhesive film 41 positioned to at least partially cover the upper strip 201. The adhesive film 41 preferably completely covers the corrugated cardboard.

[0085] The adhesive film 41 is in direct contact with the upper strip 201.

[0086] The log 300 comprises at least one tissue paper ply 400, which is wound spirally and continuously on the core 200.

[0087] The tissue paper ply 400 is in direct contact with the adhesive film 41 from the non-adhesive side.

[0088] The tissue paper ply 400 is attached to the core 200 by the innermost first spiral with an adhesive having good "release" properties that allows it to dry and peel off easily.

[0089] The core 200 can preferably be manufactured by the core winder 100 and process described above.

[0090] The core 200 of the log 300 according to the present invention is similar to known cores, but further differs in that it includes an adhesive film 41 arranged to cover the corrugated cardboard.

[0091] In fact, core 200 is intended to be extracted from log 300 afterward.

[0092] An advantage is that the adhesive film 41 applied to the corrugated cardboard core reduces friction, increases the smoothness between the core 200 and the tissue paper ply wound spirally on top of it, and makes it easier to separate the ply from the core 200 when extracting the core 200.

[0093] The core winder, process, and log configured in this manner are subject to numerous modifications and variations within the scope of the invention's concept. Furthermore, all details can be replaced by technically equivalent elements. In practice, the materials used are arbitrary, depending on the technical requirements, as long as they are suitable for the specific application, and the dimensions and associated shapes are also arbitrary.

Claims

1. A core winder (100) for forming cores (200) for tissue paper logs (300) from corrugated cardboard strips (201, 202), A dispensing station (10) configured to dispense two or more reels (11, 12) of cardboard strips (201, 202), A forming station (20) is located downstream of the dispensing station (10) and is configured to spirally wind at least the upper strip (201) and lower strip (202) dispensed from the reels (11, 12) so that they overlap each other, and to join them together to form a tube (203). A cutting station (30) is located downstream of the molding station (20) and is configured to cut the formed pipe (203) to obtain a core (200), Equipped with, The aforementioned core winder (100) The assembly includes a supply assembly (40) for the adhesive film (41), The supply assembly (40) is configured to unwind an adhesive film (41) that can be connected to the upper strip (201) in order to obtain a core (200) that is at least partially covered with the adhesive film. Core winder (100).

2. The supply assembly (40) is A spindle (42) is configured to engage with the roll (41') of the adhesive film (41) and to feed out the roll (41') while the feeding station (10) feeds out the reels (11, 12), A brake (43) configured to apply tension to the adhesive film (41) of the roll (41') that is being unfurled, The brake (43) and the control unit (44) arranged in a signal communication state, A core winder (100) according to claim 1, comprising:

3. The core winder (100) according to claim 1, wherein the supply assembly (40) is located in the dispensing station (10) which is upstream of the molding station (20).

4. The core winder (100) according to claim 1, wherein the supply assembly (40) is located downstream of the molding station (20) and upstream of the cutting station (30).

5. The core winder (100) according to claim 1, further comprising a position sensor configured to detect interruptions in the unwinding of the adhesive film (41).

6. A method for forming a core (200) for tissue paper logs from corrugated cardboard strips (201, 202), A process of unwinding two or more reels (11, 12) of corrugated cardboard strips (201, 202), The process involves winding at least the upper strip (201) and the lower strip (202) unwound from the reels (11, 12) in a spiral shape so that they overlap each other, and joining them to form a tube (203), To obtain the core (200), the process involves cutting the formed tube (203), Includes, The aforementioned method, A method characterized by including the step of unwinding an adhesive film (41) that can be connected to the upper strip (201) in order to obtain a core (200) that is at least partially covered with an adhesive film (41).

7. The method according to claim 6, further comprising the step of connecting the adhesive film (41) to the upper strip (201).

8. The method according to claim 7, wherein the connecting step is performed before the cutting step.

9. The method according to claim 7, wherein the connecting step is performed before the winding step.

10. The method according to claim 6, further comprising the step of stopping the supply assembly (40) when an interruption in the dispensing of the adhesive film (41) is detected.

11. A core (200) comprising at least an upper corrugated cardboard strip (201) and a lower corrugated cardboard strip (202) that are spirally wound and joined together so as to overlap each other, and an adhesive film (41) positioned to at least partially cover the upper strip (201), At least one tissue paper ply (400) is wound spirally and continuously on the core (200), A tissue paper log (300) equipped with [a specific feature].

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