EP2621845A1

EP2621845A1 - A method and means for the production of reels of nonwoven web or other web-like materials

Info

Publication number: EP2621845A1
Application number: EP11767804.5A
Authority: EP
Inventors: Giuseppe Acciari; Franco Lazzerini
Original assignee: A Celli Nonwovens SpA
Current assignee: A Celli Nonwovens SpA
Priority date: 2010-09-28
Filing date: 2011-09-15
Publication date: 2013-08-07
Anticipated expiration: 2031-09-15
Also published as: IT1401880B1; PL2621845T3; BR112013007122A2; CN103153828B; DK2621845T3; CN103153828A; BR112013007122B1; AR083104A1; TR201807107T4; ES2670437T3; ITFI20100204A1; EP2621845B1; WO2012042550A1

Abstract

A device is described for forming reels of web-like material around winding cores (10; 10X). To facilitate the tearing of the web-like material on completion of the winding process, one end of a tear-off tape (S) is attached to the winding core by means of an anchoring device (21). The tape is drawn from a crosswise guide 17 and wound in a helix around the winding core, thereby tearing off the web-like material.

Description

"A METHOD AND MEANS FOR THE PRODUCTION OF REELS OF NONWOVEN WEB OR OTHER WEB-LIKE MATERIALS "

Description

Technical field

The present invention relates to methods and machines for processing weblike materials and particularly, but not exclusively, for processing so-called nonwovens. The present invention specifically concerns improvements to the methods and devices for the production of reels or rolls of nonwoven and other weblike material wound around winding cores.

State of the art

The use of nonwoven webs is extremely widespread in various applications. They are used, for instance, to produce various components of baby diapers, sanitary towels and similar health products, and to make tablecloths, disposable clothing and disposable bed linen, especially for use in the medical and similar sectors.

Nonwoven is produced continuously and wound onto large reels formed around winding cores. In some cases, winding tubes are inserted over the winding cores. When winding is done directly on the core, the reel is subsequently unwound onto another machine or processing line and the core is reused to form a new reel after the previous reel has been completely unwound. When winding is done on cardboard tubes placed over the winding core, then the core can be slidingly removed from the cardboard tube and reused immediately for a new winding process. Cardboard tubes are used in particular when the nonwoven web is cut longitudinally into strips before winding, so that several reels are simultaneously formed side by side in a single step on the same winding core.

Reel-forming machines, or winders, are used to wind reels, wherein the winding cores are fed individually with the nonwoven web forming the reels. Winding is normally of the peripheral type, i.e. the core is kept pressed against one or more winding rollers. When a single winding roller is used, the nonwoven web is wound around it and the core is pushed against the winding roller by an appropriate mechanism, such as a pair of carriages engaging with the ends of the core. When two rollers are provided, the core can be placed in a winding cradle formed in between the two rollers lying on parallel axes. The web-like material is entrained around one of the two winding rollers. The winding roller, or rollers transmit(s) the rotational movement to the core and to the reel being formed around it so as to wind the required quantity of web-like material onto said core. When the winding of the reel of nonwoven web has been completed, the process is stopped and the severed end of the material is attached to a new winding core so as to enable a continuous sequential production of reels of nonwoven web.

A winder for forming reels on winding cores of the above-mentioned type is described, for instance, in WO-A-2007/096917.

Summary of the invention

The present invention relates to improvements to the methods and devices for winding reels of nonwoven web.

According to another aspect, the invention relates more in general to devices and winding cores for the production of reels of other types of web-like material.

Basically, the invention relates to improvements involving the system for severing the web-like material after completing the winding of a reel.

According to a first aspect, the invention basically involves a method for winding a nonwoven web onto winding cores comprising the following steps:

- feeding a nonwoven web onto a winding roller;

- winding the nonwoven web around a first winding core by means of said winding roller to form a reel of nonwoven web;

- juxtaposing a second winding core to the winding roller and making said second winding core rotate;

- anchoring a tear-off tape to one end of said second winding core and inducing the severing of the nonwoven web due to the effect of the helical winding of said tear-off tape around said second winding core. To ensure the proper helical winding of the tear-off tape and the tearing and anchoring of the nonwoven web to the winding core, the tear-off tape is placed inside a guide extending crosswise with respect to the machine direction, i.e. to the direction in which the nonwoven web advances through the machine. The term "crosswise with respect to the machine direction" does not necessarily mean an orientation at an angle of 90° in relation to the machine direction, because the tape can also be positioned at a slanting angle in relation to the angle orthogonal to the feeding direction of the nonwoven web. It is only necessary for it to have its ends respectively in the vicinity of the two longitudinal edges of the web-like material. _ .

One end of the tear-off tape is brought up against one end of the winding core being made ready to replace the core around which a reel is being wound. While it waits, the tape is positioned upstream from the core with respect to the web-like material so that the core and the tear-off tape occupy positions on either side of the web-like material. When the nonwoven web has to be severed, the end of the tear-off tape is anchored to the new winding core and the rotation of the latter causes the helical winding of the tear-off tape and a consequent tearing or severing of the web-like material along a line that lies helically around the winding core.

The nonwoven web is preferably a material comprising at least one textile web with at least a part of staple fibres or cut fibres and/or continuous filaments of synthetic material.

The nonwoven web preferably comprises at least 15% by weight, and more preferably at least 20% by weight, of staple fibres of a synthetic material and/or filaments of a synthetic material. For example, the fibres and/or filaments can consist at least partially of a polymeric material, such as polyester or polypropylene. In some embodiments, the fibres or filaments are bicomponent materials, with an inner core made of a material that melts at a higher temperature than that of the outer coating. The whole textile web of the nonwoven web is preferably made of synthetic fibres or synthetic continuous filaments. The term textile web is used to mean the textile part of the nonwoven web, without any binders or additives. A textile web integrally composed of synthetic staple fibres or synthetic filaments therefore does not rule out the possible presence of additives such as surfactants, binder resins, inks, super- absorbent powders or other additives, auxiliary components or fillers, needed to consolidate the textile web, or to lend it particular characteristics or functions.

The fibres or filaments that form the textile web of the nonwoven web can be consolidated in various ways. In some embodiments, this consolidation is achieved with heat, by means of a partial melting of the fibres or filaments, e.g. by softening or melting the outer structure of bicomponent fibres or filaments, preferably limited to some softening or melting areas, zones or points. In other embodiments, the nonwoven web is consolidated with a system of mechanical or preferably hydraulic entanglement process (called hydroentanglement). In other embodiments again, the consolidation is achieved by means of binder resins.

In some embodiments, the nonwoven web has a weight per unit of surface - - area in the range of 8 to 400 g/m , and preferably from 10 to 150 g/m .

It has surprisingly been found that the tape-tearing system as described above enables a severing of the nonwoven web and its adhesion to the new winding core, even with nonwovens of heavy weight per unit of surface area and despite the inclusion of a phase for consolidating the fibres or continuous filaments, which tend to make the material highly tear-resistant, or lend it a consistency that gives the impression that mechanical, laser, or hydraulic cutting mechanisms are needed, such as those used in conventional systems for winding nonwoven webs.

According to advantageous embodiments, the method described herein involves a device for anchoring one end of the tear-off tape on the winding cores. The method also involves enabling the anchoring device to attach one end of the tear- off tape to the winding core. The use of an anchoring device of this type makes the method more effective and reliable because the tape is anchored more effectively to the winding core. The use of the anchoring device avoids drawbacks deriving, for instance, from the presence of particular additives in the nonwoven web, which could make other fixing methods ineffectual, such as those involving double-sided adhesive tape. The more effective anchoring of the tape to the winding core also enables a more precise tearing of nonwoven webs that are thicker, heavier per unit of surface area, or particularly tear-resistant.

In some embodiments, the anchoring device is a mechanical device that can interact, for instance, with an actuator carried by the reel winding machine or winder. In this case, the method comprises a step for activating said anchoring device by means of said actuator associated with said winding roller after the winding of said reel of nonwoven web or other web-like material has been completed. Upon completion of the reel, the actuator is activated. The actuator co-acts with the anchoring device and causes the anchoring device to engage the end of the tear-off tape and near the end of the core. Engagement of the tear-off tape on the core starts helical winding of the tear-off tape around the core, from one end toward the opposite end of the winding core. Winding of the tear-off tape causes tearing of the web-like material and anchoring of the leading edge of the web-like material to the winding core. Embodiments and possible features of a mechanical anchoring device are described below and in the attached claims, which form an integral part of the present description. An anchoring device can also be used advantageously to actuate a tape tear- off system for severing a web-like material other than a nonwoven webs, such as paper, cardboard, embossed paper, tissue paper or other cellulose-based products.

In some embodiments, the anchoring device comprises a mechanical member carried by the winding core and torsionally connectable to and disconnectable from the winding core, the actuation of the anchoring device comprising a phase of torsional coupling between said anchoring device and the corresponding winding core on which it is supported. The end of the tear-off tape is advantageously attached to the anchoring device and is consequently wound around said winding core when the anchoring device is torsionally connected to said winding core due to the effect of the rotation of said core.

According to another aspect, a subject of the invention is also a winding core for winding a web-like material and forming a reel around said winding core, comprising a longitudinal body with a winding side wall, on which said web-like material is wound, and two ends, and wherein a device for anchoring a tape for tearing off the web-like material is associated with at least one of said ends of said winding core.

Embodiments and features of a winding core according to the invention are described below and detailed in the attached claims.

According to yet another aspect, the invention concerns a machine for the production of reels of web-like material around winding cores, comprising: a path for feeding said web-like material forward; at least one winding roller; means for feeding said winding cores towards said winding roller; and a guide for inserting a tear-off tape between said winding roller and a winding core being fed by said winding roller feeding means, said guide extending crosswise to the web-like material feeding path; and wherein an actuator is associated with said winding roller for enabling a device carried by said winding core for anchoring said tear-off tape. In some embodiments, the guide advantageously ends adjacent to one end of the winding roller and said actuator is positioned in the vicinity of said end of the winding roller.

According to another aspect again, the invention relates to a winding system for the production of reels of web-like material, comprising at least:

- a machine for the production of reels of web-like material around winding cores, comprising: a path for feeding said web-like material; at least one . . winding roller; a winding core feeder for feeding winding cores towards said winding roller; and a guide for inserting a tear-off tape between said winding roller and a winding core being fed by said feeder to said winding roller, said guide extending crosswise to the web-like material feeding path;

- at least one winding core as described above.

Brief description of the drawings

The invention is better clarified in the description given below and in the attached drawings, which show a non-limiting practical embodiment of the invention.

More in particular, in the drawings:

Figs. 1 and 2 are side views of a winder or reel-winding machine according to the invention;

Figs. 3 and 4 are views from above of the winder in Figs. 1 and 2 in two subsequent moments of the phase for severing the web-like material after completing the formation of a reel;

Figs. 5 and 6 are longitudinal sections of a device for anchoring a tear-off tape used to sever the web-like material in a first embodiment;

Figs. 7 and 8 are sections similar to those of Figs. 5 and 6 in a second embodiment of the anchoring device;

Fig. 9 is a section along ΙΧ-ΓΧ of Fig.7;

Figs. 10 A to 10D show a sequence illustrating the method for anchoring the tear-off tape to the anchoring device of Figs. 7 to 9.

Detailed description of embodiments of the invention

Figs. 1 to 4 show the main components of a winder or reel-winding machine according to the invention. The following description is limited to the components of the winder needed to understand the present invention, on the understanding that other parts of the machine not described herein are known to a person skilled in the art. For instance, the winder can be generally of the type described in WO-A- 2007/096917, the content of which forms an integral part of the present description and a person skilled in the art can find therein further details for the design of parts not described here.

Basically, the reel-winding machine or winder globally indicated by the numeral 1, comprises a winding roller 3 around which a web-like material N, and particularly, for example, a nonwoven web, is wound that is fed along a feeding path defined by a plurality of rollers 5 upstream from the winding roller 3. The winding roller 3 is motorized and turns in the direction of the arrow f3 to feed the web-like material towards a reel B being formed. The reel B is wound (Figs. 1 and 2) around a winding core globally indicated by the numeral 10. The winding core rests in a known manner on a pair of essentially horizontal guides 11 provided on the sides 13 of the machine. The reel is held with its surface pressed in a known manner against the winding roller 3 so that it is maintained in rotation due to friction against said winding roller 3 and thus takes up the web-like material or nonwoven web N fed from said roller 3.

Above the guides 11 there is a pair of guides 15 that form a store of empty winding cores 10 waiting to be fed to the winding area of the machine 1. The numeral 10X indicates a winding core positioned above the winding roller 3 and ready to replace the core 10 around which the reel B is being formed, after the latter has been completed. In a known manner, the core 10X can be made to rotate, by means of a geared wheel at the end of the core for example, before it comes into contact with the web-like material or nonwoven web N being fed around the winding roller 3.

Associated with the winding roller 3 there is a guide 17 basically consisting of a C-shaped profile that extends from a first end 17X on one side of the machine (Figs. 3 and 4) to an end 17Y on the opposite side. The "C "-shaped guide 17 has an opening that faces upwards in the portion coming between the end 17X and a curve 17Z on the side of the machine 1 opposite that of the end 17X. In line with the curve 17Z the guide bends so that the terminal end 17Y has the guide opening facing downwards.

Inside the guide 17 there is a tape or strip S, made for instance of a plastic material, paper or cardboard, and possibly reinforced with synthetic resin. The tape or strip S serves the purpose of tearing or severing the web-like nonwoven material N in a manner described later on. Near the end 17X there is a brake 18 that exerts a braking effect on the tape S. Hereinafter, this tape S is called a "tear-off tape" because it cooperates with the winding core 10, 10X to induce the severing by tearing of the nonwoven web N.

A tear-off tape S preferably slightly longer than the guide 17 is inserted in said guide so that it extends partially with one of its ends SX from the end 17Y of the _ . guide 17 towards one end of the core 10X. The end SX of the tear-off tape S thus comes to be proximal to a device for anchoring the tear-off tape S to the winding core 10X that is waiting above the winding roller 3. Figs. 1 to 4 schematically show the anchoring device identified by the numeral 21. Embodiments of said device are described below with reference to the subsequent figures.

As shown in Figs. 3 and 4, if the end SX of the tear-off tape is inserted in the anchoring device and engages with the core 10X, when the core turns in the winding direction it entrains the tear-off tape S in its rotational movement, pulling it out of the guide 17 under the tensile effect exerted thereon. The brake 18 arranged near the end 17X causes the tape S to be submitted to a tensile force sufficient to make the tear-off tape S become arranged (Fig.4) in a helix around the winding core 10X. Since the tape lies inside the guide 17 (as shown in particular in Figs. 1 and 2), it comes to be underneath the nonwoven web N when it is drawn and wound in a helix around the winding core 10X and kept taut by the braking system 18 located at the end 17X. This causes the gradual tearing or severing of the nonwoven web N starting from the end of the core 10X with which the anchoring device is associated and continuing to the opposite end, thereby generating a head of web-like material N that extends along a line sloping at an angle to that of the helix formed by the tear-off tape S around the winding core 1 OX.

In addition to achieving the severing of the web-like material N, the tear-off tape S also gradually attaches the edge of the head thus generated to the new winding core 10X. Once this has been done, winding continues in a known manner and the core 10X is lowered from the position shown in Figs. 1 and 2 into a position in which said core has its ends resting on the guides 11 of the machine 1. A pair of carriages (not shown) engage with the ends of the core projecting from the reel being formed and push the reel that is being wound around the core against the surface of the winding roller 3, thereby making the winding core and the reel continue to rotate and thus winding the web-like material N.

The anchoring device 21 provided on each winding core 10, 10X enables the reliable attachment, or anchoring, of the end SX of the tear-off tape S to the winding core even when the web-like material N (as in the case of nonwoven web) is impregnated with substances such as surfactants or other additives used in the production of the web-like material. By contaminating the surface of the winding - - core, these additives could interfere with the anchoring of the tear-off tape S to the winding core 10, 10X if other anchoring methods, such as an adhesive tape, were used. In some embodiments, the anchoring device 21 is also used to retain the end of the tape S to avoid it flapping during the winding of the material and any subsequent manufacturing processes (unwinding for rewinding).

The anchoring device 21 can be made in various ways. Figs. 5 and 6 show one embodiment of the anchoring device 21.

Figs. 5 and 6 show in particular a longitudinal section of the end of a winding core 10, 10X associated with the mechanical anchoring device 21. In this embodiment, the core 10, 10X comprises a longitudinal body 31 consisting of a longitudinal wall 33 (which is essentially cylindrical for example), the outer surface of which defines the surface on which the nonwoven web N is wound.

At the end of the core 10, 10X, inside the wall 33 of the longitudinal body 31, there is a pin 35 fixed coaxially to the body 31 of the core 10, 10X, the axis of which lies along A-A. The pin 35 also extends outside the wall 33 and a sleeve 37 is idly thereon. The sleeve 37 is idly supported by bearings 38 in an area of the pin 35 having a narrower diameter. Outside the sleeve 37, there is a wheel 39 keyed onto the pin 35, that can be used to entrain the winding core 10, 10X in rotation before it comes into contact with the web-like material N being wound around the winding roller 3, all in a basically known manner.

A flange 41 is fixed to the sleeve 37 and faces towards the body 31 of the winding core 10, 10X. The flange 41 carries one or more magnets 43, which are preferably permanent magnets. In one embodiment, for example, there may be a single, ring-shaped magnet 43. Alternatively, there may be two, three, four, or more magnets 43, preferably arranged with a uniform angular pitch around the axis A-A of the winding core 10, 10X.

Cooperating with the permanent magnet(s) 43 there is a basically disc-shaped cursor, globally indicated by the numeral 45, that is mounted slidingly on the pin 35 by means of bearings (e.g. sliding bearings), schematically indicated by the numeral 47 and contained inside a bushing 49 coaxial with the pin 35.

In some embodiments, the cursor 45 is composed of two portions. More in particular, in the embodiment illustrated, the cursor 45 has a first disc-shaped element 51 integral with the bushing 49, or forming part of the same piece as the latter. The disc-shaped element can advantageously include a ring 53 of elastically compressible material, e.g. plastic or rubber, cooperating in the manner described below with the circular terminal edge 33B of the cylindrical wall 33 forming the longitudinal body 31 of the winding core 10. The elasticity under compression of the material forming the ring 53 prevents the pressure between the edge 33B and the disc-shaped element 51 from cutting or severing the tear-off tape S during the use of the device 21.

A second portion of the cursor 45 is supported on the disc-shaped element 51 by means of a bearing 55. This second portion, which is also basically disc-shaped in the example illustrated, will hereinafter be indicated as the actuating element 57. The elements 51 and 57 are axially connected to one another but, due to the effect of the bearing 55, they are not torsionally coupled to one another and the disc-shaped element 51 can consequently rotate freely around the axis A-A of the winding core 10, independently from the actuating element 57.

A retainer device globally indicated by the numeral 61 can be advantageously associated with the cursor 45 so that, in the manner explained below, in particular operating conditions it keeps the cursor 45 abutting against the edge 33B of the wall 33, as shown in Fig.6.

In the embodiment illustrated, the retainer device 61 comprises a housing 63 integral with the wall 33 forming the longitudinal body of the core 31. Inside said housing, a stem 65 slides with its end 65A attached to the cursor 45 and, more precisely, to the disc-shaped element 51 of the cursor 45. The opposite end of the stem 65 has a striker plate 67 arranged so that a spiral compression spring 69 remains preloaded between the striker plate 67 and the bottom 63 A of the housing 63. When the cursor 45 is not connected to the magnets 43, it is kept abutting against the circular edge 33B under the effect of the thrust brought to bear by the compression spring 69. In some embodiments, there may be several retainer devices 61 arranged around the axis A-A of the winding core. The disc-shaped element 51 is torsionally connected to the core due to the effect of the presence and the particular shape of the retainer device 61. Thus, in this embodiment, when the winding core 10, 10X rotates around its own axis A-A, the disc-shaped element 51 also rotates with the core.

It is important to note that the device for retaining the cursor 45 on the winding core 10, 10X against the edge 33B may have a different shape from the one illustrated. For example, there may be radially engaging members that are elastically inserted inside cavities on the lateral surface of the bushing 49.

In the arrangement illustrated in Fig. 5, the cursor 45 is retained by the permanent magnets 43 that thus serve as a second retainer device, the action of which opposes that of the first retainer device 61. In this arrangement, between the cursor 45 (and, more precisely, the ring 53 integral therewith) and the edge 33B of the wall 33 there is a distance D greater than the width of a tear-off tape S. The tear-off tape S could also be inserted at a 90° angle in relation to its longitudinal length and, in this case, the distance D could be smaller (slightly greater than the thickness of the tape, instead of its width).

When the winding core 10 is inserted in the machine, occupying the position indicated by numeral 10X in Figs. 1 and 2, the mechanical anchoring device comes to be in the position shown in Fig.5 and located so that the space defined between the edge 33B and the ring 53 is in line with the end SX of the tear-off tape, i.e. the tape is positioned inside this space. In the arrangement shown in Fig. 5, the end SX of the tear-off tape S does not engage with the device 21, which can therefore rotate freely together with the winding core 10, 10X so that said core can be made to rotate at the peripheral speed corresponding to the speed of the web-like material N.

Near the device 21, there is an actuator in the winder consisting, for example, of a pair of cylinder-piston systems 81, carried by a fixed structure 83, as shown schematically in Figs. 5 and 6. The stems 82 of the cylinder-piston actuators 81 come to be facing the actuating element 57 of the cursor 45 and slightly distanced therefrom. When the tear-off tape S must be anchored to the core 10X, which has already started rotating, the actuators 81 are enabled so that they push the cursor 45 with the stems 82. The force exerted by the stems 82 of the cylinder-piston actuators 81 is sufficient to overcome the magnetic retaining force exerted by the magnets 43 so that the cursor 45 becomes detached from the flange 41 with the magnet 43 and occupies the position illustrated in Fig. 6.

In this position, the end SX of the tear-off tape S remains trapped between the ring 53 and the edge 33B of the wall 33, sufficient pressure being exerted between these two elements thanks to the continuing thrust exerted by the stems 82 of the cylinder-piston actuators 81. The winding core 10, 10X is rotating around its axis A- A. The disc-shaped element 51 is torsionally connected to the winding core 10, 10X and thus rotates with the latter. The tear-off tape S, held between the edge 33B of the wall 33 of the core 10, 10X and the disc-shaped element 51, begins to wind helically around the wall 33 forming the body 31 of the winding core 10, 10X.

Thanks to the torsional uncoupling achieved by means of the bearing 55 the actuating element 57 is not involved in the rotational movement around the axis A-A of the winding core 10, 10X, while it remains torsionally engaged with the stems 82 of the cylinder-piston actuators 81. This condition persists so long as it is necessary to exert a sufficient retaining force on the end SX of the tear-off tape S and said retaining force cannot be achieved due to the effect of the spring 69 of the retainer device 61 alone.

Once the tear-off tape S has been completely wound in a helix around the winding core 10, 10X and the web-like material N has begun to wind around said winding core, it is no longer necessary to exert a strong retaining force on the end SX of the tear-off tape S and the cylinder-piston actuators 81 can thus be disabled. In these conditions, the cursor 45 remains in the arrangement shown in Fig. 6 due to the effect of the compression spring 69 of the retainer device 61 alone until the moment in which the core is removed from the reel that has been formed so that it can be used for another winding cycle. Before the core is used in the next cycle, the anchoring device 21 is "reset", a procedure that involves the transfer of the cursor 45 along the pin 35 against the force of the spring 69 of the retainer device 61 until the actuating element 57 engages magnetically with the magnets 43 carried by the flange 41 integral with the sleeve 37.

Figs. 7 to 10 show a modified embodiment of the device for anchoring the tear-off tape S. The same numbers are used to indicate the same or equivalent parts corresponding to those illustrated in Figs. 5 and 6.

In this embodiment, an element 91 for anchoring the tear-off tape S is associated with the disc-shaped element 51 (complete with the ring 53 of elastically compressible material that advantageously has a high friction coefficient, which cooperates with the edge 33B of the wall 33). The function and structure of the anchoring member 91 are easier to understand by referring to Figs. 9 and 10, which show a section of the anchoring member 91 along the plane ΓΧ-ΓΧ of Fig. 7.

In this case, the disc-shaped element 51 is torsionally as well as axially disconnected from the core 10, 10X and can consequently remain still when the core 10; 10X begins to rotate around its axis A- A.

The tear-off tape S is connected in this case with its end SX to the anchoring member 91, which is torsionally coupled to the disc-shaped element 51 and begins to rotate therewith when, due to the effect of the cylinder-piston actuators 81, the cursor 45 is pushed until the ring 53 abuts against the edge 33B of the wall 33 of the winding core 10, 10X. Before the cylinder-piston actuators 81 take effect by pressing the disc-shaped element 51 against the edge 33B of the wall 33 of the winding core 10, 10X, the disc-shaped element 51 does not rotate; it remains idly supported on the pin 35. In the embodiment shown in Figs. 9 and 10, the anchoring member 91 has a plurality of curved blades 91 A arranged around the axis A- A of the winding core 10, 10A to form a set of fin-like elements extending radially outwardly. The blades 91 A are contained inside a space formed between two ring-shaped crowns 91 B and 91 C integral with the disc-shaped element 51. The ring 91 C faces towards the one or more magnets 43 carried by the flange 41 integral with the sleeve 37 mounted idly on the pin 35 of the winding core 10, 10X. When the cylinder-piston actuators 81 push with the stems 82 against the actuating element 57, the latter causes the detachment of the cursor 45 and, more precisely, of the ring 91 C from the one or more permanent magnets 43, inducing the juxtaposition and consequent torsional coupling due to friction of the cursor 45 with the wall 33 of the winding core 10, 10X. The disc- shaped element 51 is torsionally coupled with the winding core 10, 10X and begins to rotate therewith, while the actuating element 57 remains angularly fixed and temporarily coupled to the stems 82 of the cylinder-piston actuators 81.

When the end SX of the tear-off tape S is inserted in the space between the rings 9 IB, 91 C, the curved blades 91 A engage with the end SX of the tear-off tape S to prevent it from sliding out, as shown in the sequence of Figs. 10A to 10D, when the anchoring member 91 begins to rotate around the axis A- A. Basically, therefore, when the components 51, 91 are torsionally connected to the winding core 10, 10X, the anchoring member 91 rotates integrally with the core, the curved blades 91 A retaining the end SX of the tear-off tape, which begins to wind helically around the winding core 10, 10X, tearing the web-like material N as described previously.

It is important to note that the anchoring member 91 can also be of a different shape, with other mechanisms for engaging with the tear-off tape SX. For example, there could be teeth, pressure pads, nails, hooks or other means by which the user can fix the end SX of the tear-off tape S. The embodiment illustrated is particularly advantageous because it does not require any manual action by the operator on the device for anchoring the tear-off tape S, since it suffices to insert its end SX between the hub of the anchoring device 45 and the curved blades 1 A. The mechanical constraint between the head or end SX of the tear-off tape S and the mechanical anchoring member 91 is thus achieved by simply rotating the member 91 due to the effect of the shape of the blades 91 A and the position of the end SX of the tear-off tape S.

Here again in this embodiment, the cursor 45 remains pressed against the edge 33B of the wall 33 of the winding core 10, 10X even when the cylinder-piston actuators 81 are disabled and the core 10, 10X moves away from them, taking a different position in the winding machine. This juxtaposition is guaranteed by the presence of compression springs in the retainer devices 61. In this case, the retainer devices 61 are supported by the sleeve 37. They also serve the same purpose as the retainer device 61 described with reference to Figs. 5 and 6. The force of the springs of the retainer devices 61 ensures that the cursor 45 remains engaged with the winding core, keeping the end of the tear-off tape S stably attached to the core, and preventing it from flapping while the winding core rotates, both during the reel B forming phase and during any subsequent unwinding phase.

As in the example in Figs. 5 and 6, so too in this case, the device 21 must be

"reset" before it can be reused, bringing the cursor 45 to engage with the one or more permanent magnets 43.

Needless to say, the drawings only show an example, given simply as a practical demonstration of the invention, which can vary in format and layout without departing from the scope of the inventive concept. Any presence of reference numbers in the attached claims is merely to facilitate the reading of the claims with reference to the description and the drawings, and shall not be construed to limit the scope of the patent as explained in the claims.

Claims

1. A method for winding a web-like material onto winding cores comprising the following stages:

- feeding a web-like materialto a winding roller;

- winding the web-like materialby means of said winding roller around a first winding core to form a reel of web-like material;

- approaching a second winding core to the winding roller and driving said second winding core into rotation;

- providing an anchoring device arranged on said second winding core for anchoring one end of a tear-off tape to said second winding core;

- actuating said anchoring device by means of an actuator associated with said winding roller on completion of the winding of said reel of web-like material on said first winding core, to anchor said end of the tear-off tape to said second winding core; - causing severing of the web-like material by helically winding said tear-off tape around said second winding core.

2. Method according to claim 1, wherein said web-like material is a nonwoven web.

3. Method according to claim 2, wherein said nonwoven web comprises at least one textile web at least partly consisting of staple fibres and/or continuous filaments of synthetic material.

4. Method according to claim 2 or 3, wherein said nonwoven web comprises at least 15% by weight, and preferably at least 20% by weight, of staple fibres of synthetic material and/or filaments of synthetic material.

5. Method according to claim 3 or 4, wherein said synthetic material is a polymeric material.

6. Method according to claim 3, 4 or 5, wherein said synthetic material is a polymeric material chosen from the group comprising polyester and polypropylene.

7. Method according to one or more of the claims 3 to 6, wherein said nonwoven web comprises continuous filaments of polymeric material.

8. Method according to one or more of the claims 3 to 7, wherein said nonwoven web comprises a textile web consisting exclusively of continuous filaments of synthetic material and/or staple fibres of synthetic material.

9. Method according to one or more of the claims 3 to 8, wherein said nonwoven web comprises a textile web consisting of discontinuous fibres.

10. Method according to one or more of the claims 3 to 9, wherein said fibres and/or continuous filaments are thermally bonded by means of a partial melting process.

11. Method according to one or more of the claims 3 to 10, wherein said staple fibres and/or said continuous filaments are bonded by means of at least one chemical resin.

12. Method according to one or more of the claims 3 to 10, wherein said staple fibres and/or continuous filaments are bonded by means of a hydro- entanglement procedure.

13. Method according to one or more of claims 2 to 12, wherein said nonwoven web has a weight per unit of surface area in the range of 8 to 400 g/m², and preferably in the range of 10 to 150 g/m .

14. Method according to one or more of the previous claims, wherein said anchoring device comprises a mechanical member sliding axially in relation to a wall of the winding core to make the tear-off tape become attached to the winding core, the actuation of the anchoring device comprising a step for pressing and holding one end of said tear-off tape between said wall of the winding core and said mechanical member.

15. Method according to one or more of the previous claims, wherein said anchoring device comprises a mechanical member torsionally connectable to and disconnectable from said winding core, the actuation of the anchoring device comprising a step for torsionally connecting at least one portion of said anchoring device to said winding core, the end of the tear-off tape being anchored to said at least one portion of the anchoring device and consequently being wound around said winding core when the anchoring device is torsionally connected to said winding core.

16. A winding core for winding a web-like material and forming a reel around said winding core, comprising a longitudinal body with a side winding wall, on which said web-like material is wound, and two ends, at least one of said ends being associated with a device for anchoring a tear-off tape to said winding core; wherein said anchoring device comprises a cursor axially movable in relation to said longitudinal body and cooperating with said side wall.

17. Winding core according to claim 16, wherein said cursor is supported on a stem coaxial to said side wall of the winding core.

18. Winding core according to claim 17, wherein said cursor comprises a first portion that can be torsionally connected to and disconnected from the lateral wall of the winding core.

19. Winding core according to claim 18, wherein said cursor comprises a second portion torsionally disconnected from said first portion and idle in relation thereto.

20. Winding core according to one or more of the claims 16 to 19, wherein said cursor comprises a gripping element for attaching said tear-off tape of the web-like material to said winding core.

21. Winding core according to claim 20, wherein said gripping element comprises a pressure-applying surface cooperating with a terminal edge of said lateral winding wall facing said pressure-applying surface, the gripping element being connected to said side wall when the pressure-applying surface is pressed against said terminal edge.

22. Winding core according to one or more of the claims 16 to 21, wherein said cursor comprises a disc-shaped element cooperating with said side wall and torsionally connectable to, or connected to said side wall, and an actuating element, idly supported in relation to the longitudinal axis of said winding core, and interfaceable with an external actuator, said actuating element being positioned and controlled so as to connect said disc-shaped element to said side wall of the winding core.

23. Winding core according to claim 22, wherein said disc-shaped element comprises a pressure-applying surface facing a terminal edge of said side wall of the winding core, said disc-shaped element being pressed with said pressure-applying surface by said actuating element against the terminal edge of the side wall of the winding core so as to connect said disc-shaped element to said side wall of the winding core, while the actuating element remains torsionally disconnected from said side wall of the winding core.

24. Winding core according to claim 22, wherein said disc-shaped element is integral with a device for anchoring the end of said tear-off tape.

25. Winding core according to claim 22 or 23 or 24, wherein said actuating element is idly supported on said disc-shaped element.

26. Winding core according to one or more of the claims from 16 to 25 comprising a first cursor retaining device that keeps said cursor in a position connected to said side wall of the winding core.

27. Winding core according to claim 26, comprising a second cursor retaining device that keeps said cursor in a position disconnected from said side wall of the winding core.

28. Winding core according to claim 27 comprising a sleeve coaxial to said side wall and idle in relation thereto, said sleeve being stationary in relation to the side wall and carrying said second retaining device.

29. A machine for the production of reels of web-like material formed around winding cores comprising: a path for feeding said web-like material; at least one winding roller; means for feeding said winding cores towards said winding roller; and a guide for inserting a tear-off tape between said winding roller and a winding core fed by said feeder towards said winding roller, said guide extending crosswise to the web-like material feeding path; and wherein an actuator is associated with said winding roller to activate a device for anchoring said tear-off tape, carried by said winding core.

30. Machine according to claim 29, wherein said guide ends adjacently to one end of said winding roller, and wherein said actuator is positioned in the vicinity of said end of the winding roller.

31. Machine according to claim 29 or 30, comprising at least one winding core according to one of more of the claims from 16 to 28 is provided.

32. A machine according to claim 29, 30 or 31, wherein a brake is associated with said guide, for tensioning the tear-off tape.

33. A winding system for the production of reels of web-like material comprising at least:

- a machine for the production of reels of web-like material formed around winding cores comprising: a path for feeding said web- like material; at least one winding roller; means for feeding said winding cores towards said winding roller; and a guide for inserting a tear-off tape between said winding roller and a winding core fed by said feed means to said winding roller, said guide extending crosswise to the web-like material feeding path;

- at least one winding core according to one or more of the claims from 16 to 28.