EP2252534B1 - Paper roll with central hole and reinforcing member, and method for making said roll - Google Patents

Abstract

A roll of sheet product, in particular of tissue paper, with a central hole along its winding axis includes a cylindrical reinforcing element onto which the paper is wound. The reinforcing element includes at least one ring joined to the innermost turn of the roll, with a width less than the width of the roll and provided with a means of extracting the ring by pulling substantially along the axis of the roll.

Description

The present invention relates to the field of rolls of tissue paper or other similar material such as a nonwoven. It relates in particular to the field of products for sanitary and / or domestic use such as wiping rolls, towels or toilet paper.

"Tissue paper" means a paper whose characteristics are defined by the European standard EN 12625-1 . A roll is formed by winding-a continuous sheet which is composed of one or more folds of paper. The sheet is optionally precut in consecutive coupons in the direction of the winding, and is wound, preferably about an axis or a pin that can support or not a mandrel; the roll can thus comprise a central mandrel or not.

Depending on the application, the roll is unwound, either from its outer surface in the direction of the winding perpendicular to its axis, it is called tangential unwinding, or from the inside from the center in its axial direction. In the latter case, it is said that the roll is centrally rewind.

The present invention relates to rollers having a central, center-fed, and tangential-winding roll.

When the roll is for a center-feed type application, it may include a mandrel. The mandrel is a cardboard cylinder that extends over the width of the roll. It is generally formed of a cardboard strip wound helically spiral. In this case, it must first be extracted when the roller is put into service. For example, the mandrel can be designed so that it can be torn off when its edge is pulled at one end of the spiral cardboard spiral that forms it. However, practice shows that this solution is not always satisfactory, because the extraction of the mandrel is sometimes difficult if the fracture zone or areas are poorly formed. In addition, it can cause the first roll sheets that become difficult to use. The first turns of the sheet being most often glued to the mandrel, they are unfit for any use and are a waste.

This type of mandrel is expensive to produce, since it is generally composed of two or more bonded layers of cardboard and is associated with an adhesive "hook" of the first turn of the roll. It is no longer useful once removed, and becomes a waste.

To overcome this disadvantage, it is also proposed, according to the prior art, central unwind rolls without mandrel. These are a priori easier to implement by the user, because it is no longer necessary to remove a mandrel prior to their commissioning. To achieve these, one can, in manufacture, provide a temporary mandrel forming a pin on which the sheet is wound. The spindle is then removed before the rolls are packed. This technique presents constraints on the industrial level because it is necessary to add a pin extraction station to the winding line.

According to a method of manufacture without known chuck, the sheet is cut in line in the direction of the latter or longitudinal, before winding on the spindle, from a sheet of large width, in as many strips as individual rolls to obtain.

According to another method of manufacture, the mother sheet is wound directly on a pin, also without the interposition of a mandrel. The initial sheet, which is large in width, is first rolled up to form a single coil with the final diameter of the individual roll, called "log" in the field. After training, the log is extracted from the spindle and cut into individual rolls.

However, the sheet, whether cellulose wadding, creped dry or wet, dry paper or a nonwoven, has some elasticity. Because of the internal stresses of the roll, due for example to the clamping of the sheet on the spindle during the winding and / or the tension of the sheet that generates the unwinding / winding operation by the machine, it can not be avoided normally. reducing the diameter of the central hole by collapsing or collapsing at the center of the first turns after the pin has been removed. This collapse occurs, for example, after extraction of the spindle or at the time of cutting log, the pressure exerted by the saw or during packaging and overpacking operations.

There is a partial or total reduction of the central hole during handling and transport, due to vibrations and inevitable pressures to which the rollers are subjected.

When the central hole is completely reduced, it is difficult to reform at least by hand, and the grip of the first turn is not easy. It inevitably follows waste, especially the commissioning of the roller in a dispenser, because it is then necessary to grasp several turns at a time.

It is known to produce mandrelless rollers whose central hole remains formed after extraction of the spindle and / or after cutting by a saw. We can use for example a spindle whose profile, grooved or polygonal section, allows the formation of a central hole whose walls are self-supporting. An exemplary embodiment is illustrated by the patent FR 2,554,799 .

If the central hole is small diameter the first turns remain difficult to access. The primer is a tight, helical, low-pitched torch that is not conducive to easy extraction.

If the diameter of the central hole is larger, it is necessary to associate the first turns between them. For this, we apply a bonding agent that is deposited directly on the sheet or indirectly via the spindle on the winding rolls, by a suitable system, at the time of winding of the first turns on the spindle. Any other principle of association of the first turns with each other, by a mechanical process in particular, is applicable. We thus consolidate these first turns which together withstand the efforts of internal constraints.

However, again, the waste can not be avoided during the commissioning of such a roll. Whether in the case of a direct use or in the case where one would use this roll in a central dispenser in which we must introduce the end of the sheet into a relatively narrow dispensing orifice, we are obliged to eliminate beforehand the first coils associated with each other.

In this latter embodiment, it is not possible for certain rollers to avoid sagging of the central hole, as in the cases mentioned above, because of shocks during transport. To avoid this risk, it is also expected to preferentially condition the rolls in cardboard boxes, unlike rollers with mandrel that are sufficient of a flexible envelope of paper or plastic. The cost is increased.

The interest that could be found in these mandrel-free rolls with respect to the mandrel rollers is thus diminished.

In the patent application DE 19946272 A1 , there is described a roll of tissue paper for which the mandrel is replaced by one or more rings whose total length is less than the length of the roll.

The Applicant has developed a mandrel-free mandrel-type roller comprising a central unwinding primer along its axis, intended to facilitate the gripping of the innermost turns of the roller. This technique is described in patent applications FR 2 869 891 and EP 1 636 123 . This is a specific solution to the problem of the collapse of the central hole of rolls without mandrel.

The present invention provides a different and inventive solution to this same problem and applies not only to the so-called center-fed rollers, but also to the tangential unwinding rollers.

Thus, the present invention relates to a roll of paper, especially tissue paper, comprising a central hole along its winding axis with a cylindrical reinforcing element on which the paper is wound and characterized in that said reinforcing element comprises at least one ring integral with the innermost turn of the roll, the ring being of width less than the width of the roll and provided with a means for extracting the ring by traction substantially along the axis of the roll .

Thanks to the invention, the ring or rings allow support of the hole from its manufacture, and until the end use, with little additional material vis-à-vis a roll without mandrel and without special reinforcement.

According to one embodiment, the ring comprises at least one slot allowing, from the outer edge of the ring, to fold the material constituting the ring towards the axis of the roll and thus to provide a tongue forming said extraction means. .

More particularly, the slot follows the curvature of the ring and is in particular an arc. The slot is preferably perpendicular to the axis of the ring. The extraction means is formed of the inwardly folded arcuate portion extending from the axial edge of the ring.

According to one variant, the slot is axial. Preferably the slot extends from one edge of the ring over a portion of the width of the ring. The extraction means is formed of the portion of the ring folded towards the axis of the roll.

Advantageously, the roll has two or more slots for increasing the number of gripping means forming the extraction means.

The ring is preferably made of cardboard, flush with or near one of the sides of the roll.

According to another variant, the ring comprises at least two layers with an outer layer in contact with the sheet of paper and an inner layer towards the axis of the roll, with a means for extracting the inner layer. This embodiment makes it easier to initiate the extraction of the ring when the sheet is tightened on the ring and exerts a significant pressure, the inner layer being subjected to less pressure than the layer directly in contact with the sheet. .

According to one embodiment of this variant, the ring is advantageously corrugated with a corrugated layer between two non-corrugated layers or formed of folds of different grammages including higher grammage for radially internal folds.

According to another embodiment of this variant, the outer layer and the inner layer are glued to each other, a part of the inner layer in contact with the outer layer not being bonded to the outer layer and forming the extraction means of the inner layer.

More particularly, the ring comprises at least two layers with an outer layer in contact with the sheet of paper and an inner layer towards the axis of the roll, the two layers being formed of helical turns, the turns of the inner layer partly overlapping and not being bound in the overlap area. According to a preferred embodiment, the turns of the outer layer and the turns of the inner layer are wound at the same winding angle and the turns of the inner layer have a width greater than that of the turns of the outer layer of to create said overlap. In particular, the turns of the outer layer are contiguous or substantially joined; they may not be perfectly joined.

According to another variant, the ring has a zone deformed by displacement towards the axis of the roller so as to form a spoiler.

According to another characteristic, the ring is held by gluing on at least said innermost turn of the roll.

According to a variant, the ring is held by mechanical connection on at least said innermost turn of the roll.

According to another characteristic, the ring has a width less than half the width of the roll, preferably less than one third of the width of the roll and more particularly less than a quarter of the width of the roll. The width is preferably at least one seventh of the width.

This dimension reduces the cost of the material to a chuck solution over the entire width of the roll, while being sufficient to prevent collapse of the central hole.

Advantageously, at least the ring has a thickness of between 0.1 and 4 mm. Depending on the material used, the thickness of the wall of the ring is determined to ensure sufficient resistance to crushing.

When necessary to maintain the hole a second ring is disposed in the central hole near the other edge. It can be maintained without sticking in the hole to the extent that it does not participate in the extraction of the sheet. It can also in the case of use with tangential unwinding forming a support bearing on an axis of the distributor on which the roller is installed.

The invention also relates to the use of a roll in a center-fed paper dispensing system.

A method of manufacturing a roll according to the invention comprises placing on a spindle rings arranged for, after transverse cutting forming two of said rings, to provide an extraction means on each of said rings, the winding of a large sheet on the spindle, the extraction of the spindle and the log section obtained across said rings so as to obtain rollers with said rings. If necessary, the rings are temporarily fixed in rotation and in translation on the spindle, the time to allow the winding of the sheet without sliding. Preferably the rings are fixed temporarily on the spindle by mechanical means, in particular by crimping. Another method of manufacture includes placing rings in the central hole in the roll after the roll has been wound.

If we consider an embodiment with tangential unwinding, the reinforcing element may comprise a first and a second ring each bonded to at least said innermost turn of the roll and each being intended to serve as a rotary support for the roll .

• La figure 1 est une vue schématique en perspective d'un rouleau avec deux anneaux pour une utilisation avec dévidage tangentiel;
• La figure 2 est une vue schématique en perspective d'un rouleau avec deux anneaux pour un dévidage central ;
• La figure 3 est une autre vue schématique en perspective d'un rouleau avec un seul anneau.
• La figure 4 représente deux rouleaux avec un moyen d'extraction conforme à l'invention, l'un en position avant mise en service l'autre avec le moyen d'extraction dégagé ;
• La figure 5 représente un autre mode de réalisation de l'invention avec un anneau dans lequel on dégage des languettes ;
• La figure 6 montre schématiquement une étape de fabrication des rouleaux avec formation d'un log et son sciage en rouleaux individuels
• La figure 7 montre un anneau double formant une bague du mode de réalisation de la figure 4 ;
• La figure 8 montre un anneau double formant une bague du mode de réalisation de la figure 5 ;
• La figure 9 montre une variante de réalisation de l'invention avec un anneau formé de carton ondulé ;
• La figure 10 montre une autre variante de réalisation de l'invention avec un anneau formé d'une bande en spirale ;
• La figure 11 montre une variante de réalisation avec un anneau multiplis ;
• La figure 12 montre une autre variante avec un anneau formant un becquet ;
• La figure 13 montre une autre variante de réalisation de l'anneau par enroulement en hélice de deux bandes.

Other features, details and advantages of the invention will emerge from the following description, given by way of illustration and in no way limitative, with reference to the appended drawings in which:

• The figure 1 is a schematic perspective view of a roll with two rings for use with tangential unwinding;
• The figure 2 is a schematic perspective view of a roller with two rings for central unwinding;
• The figure 3 is another schematic perspective view of a roll with a single ring.
• The figure 4 represents two rollers with extraction means according to the invention, one in position before commissioning the other with the extraction means disengaged;
• The figure 5 represents another embodiment of the invention with a ring in which tabs are disengaged;
• The figure 6 shows schematically a stage of manufacture of the rollers with formation of a log and its sawing in individual rolls
• The figure 7 shows a double ring forming a ring of the embodiment of the figure 4 ;
• The figure 8 shows a double ring forming a ring of the embodiment of the figure 5 ;
• The figure 9 shows an alternative embodiment of the invention with a ring formed of corrugated cardboard;
• The figure 10 shows another alternative embodiment of the invention with a ring formed of a spiral band;
• The figure 11 shows an alternative embodiment with a multiplied ring;
• The figure 12 shows another variant with a ring forming a spoiler;
• The figure 13 shows another embodiment of the ring by helically winding two strips.

The Figures 1 to 3 illustrate roller embodiments according to the application filed on 04/02/2008 under the registration number FR 0800581 by the plaintiff.

The rolled sheet is an absorbent paper for sanitary or domestic use. It is a paper obtained wet, creped or not, preferably a tissue paper. It can also be dry paper or a nonwoven. The embodiment of the figure 1 illustrates a particularly suitable roll for a tangential feeding use for which the sheet is unwound from the cylindrical outer surface.

The roller 1 comprises a central recess (or hole) 2, cylindrical or substantially cylindrical, generally created during the formation of the turns. In the central recess 2 are arranged two rings 31, 32 each near a flat flank 4 of the roll 1 or flush with it. The rings 31, 32 are put in place either simultaneously or after the formation of the roll.

In known embodiments, the axis of the rolls without mandrel is in fact made of a sheet of paper wound at its center, with crumpled turns. It follows a problem of attachment to the axis of the distributor, with braking or blocking rotation.

According to this embodiment the two rings 31, 32 serve as a rotational support for the fixed element (axis) around which the roller can rotate, reduce friction between these parts, thereby improving the rotation of the roller on its support and therefore the unwinding the paper on the roll 1. Each of the rings 31, 32 is bonded by bonding its outer surface to the innermost turn of the roll. Two lines of glue 5, 6 are provided along two circumferences of each ring. The connection can also for example be made with glue points and / or lugs, protuberances which protrude from the outer surface of the ring 31, 32 and come hang on. in the first turn (s). The bond may be of a chemical or mechanical nature.

The width of each ring 31, 32 is here substantially the same, in order to better distribute the external forces on each ring. The ring width is less than half the width of the roll, preferably less than one third or even one fifth of that of the roll. For example, it is between 10 mm and 50 mm and more preferably between 15 mm and 25 mm.

Moreover, depending on the nature of the material of the ring, its thickness is between 0.1 mm and 4 mm.

The two rings 31, 32 are connected to the innermost turns of the roller and they serve as a support bearing on the element (s) (axes) fixed that support (s) the roller, ensuring its perfect rotation.

According to figure 2 , two rings 31, 32 are integrated in the recess (hole) central 2. Here the two rings 31, 32 are not identical: one of the rings, 31, corresponds to the technical description given above in this sense it is initially totally bound to the interior of the recess 2 (for example by glue lines 5, 6). The second ring 32, disposed near the second side (not referenced) of the roll 1 has a width less than that of the first ring 31; it is not fixed by gluing or other means inside the recess 2, but is simply placed or pressed or force-fitted. Here the first ring 31 serves to prevent the collapse of the central recess 2, and to extract the innermost turns of the roll 1.

The user grasps the ring 32 (not linked to the first turns), pulls it axially towards the outside of the roll, This ring 32 has an anti-collapse function of the recess 2, either during the manufacture of the roll or during from its use Then the user grasps the ring 31 and pulls axially outwardly of the roll thus initiating the first turns and the central unwinding of the roll 1.,

Proper identification (visual or otherwise) may be provided to differentiate the two rings, indicating for example that an extraction must be performed at the level of the first ring 31.

The figure 3 illustrates another embodiment that differs from that of the figure 2 by the absence of the second ring 32. The only ring provided 31 has the characteristics described above: it is fixed inside the recess 2, near one of the flanks 4 of the roll 1. The single ring 31 is sufficient to prevent the collapse of the turns, and this ring can further be used to extract the innermost turns of the roll 1, even if the recess on the side opposite the ring 31 is collapsed, collapsed. The mode of realization according to the figure 3 with a single ring 31, can be used for tangential unwinding in the case where only one fixed element is provided for supporting the roll 1.

Whatever the embodiments, the ring or rings 31, 32 are made of a sufficiently strong material not to collapse under the effect of the internal pressure of the roller. Directed deformation can, however, be used to facilitate extraction as is further developed. They are preferably in a recyclable material such as cardboard.

According to the present invention, at least one of the rings is provided with a means assisting the extraction out of the central hole at the time of commissioning of the roll.

On the figure 4 there is shown a first embodiment of the extraction means. The cylindrical roller 10 is formed of the winding of a sheet about an axis and comprises a central hole 13 along this axis. A ring 40 is housed in the hole near the sidewall 14 of the roll. Only one ring is visible. The roll may have two. The width of the ring is smaller than that of the roll. For a 100 mm wide roll, the ring preferably has a width of between 15 and 25 mm.

An extraction means 42 is formed of a portion of the ring delimited by a slot 41 in a circular arc, in particular parallel to the sidewall 14. The length of the arc is less than half a circumference. The extraction means is released by deforming this ring portion towards the axis of the roll. As can be seen on a roll of the figure, two extraction means 42 have been provided. To extract the ring, the fingers are slid into the hole and the two means 42 are gripped. causes the ring. If the ring is bound to the innermost sheet of the roll it is also dragged. The slot may be any shape along the curved surface of the ring as it allows the portion to bend toward the center to form a finger grip.

On the figure 5 another embodiment of the extraction means has been shown; the roll 10 as above comprises at least one ring 50 near the sidewall 14. This ring 50 comprises at least one axial slot 51 which extends from an edge, the edge located on the side of the sidewall 14. It may also be the edge opposite the flank 14. The slot extends over a portion of the width of the ring.

As we see on the figure 5 the ring here comprises two mutually parallel slots extending to the spiral junction 53 of the edges of the cardboard web which has been spirally wound to form the tube constituting the ring. This allows to create the slots 51 from the manufacture of the tube constituting the ring.

The two slots form between them a tongue 52.

To extract the ring from the central hole, the tongue 52 is folded towards the axis of the roll to disengage it. This tab is pulled outward to extract the ring. As in the previous case if the sheet is tied to the ring, it is dragged with it.

These solutions are advantageous in terms of the manufacture of rollers because they do not cause substantial changes. On the figure 6 an example of a manufacturing step has been schematized. The log 100 was formed by winding a wide sheet to the desired roll diameter and then slice the log by means of a saw S in individual rolls 10. The sheet was wound on a not shown pin and on this pin on has previously arranged double rings at regular intervals, each double ring forming a ring. Advantageously, the rings are fixed temporarily in rotation and in translation on the spindle in order to allow the sheet to be wound on the spindle and then extracted.

The rings are temporarily fixed on the spindle preferably by mechanical means, in particular by crimping. The rolls are obtained by sawing the log through the double rings. On the figure 7 , we see a ring 40 'with slots 41 transverse arcuate. By sawing the ring 40 'between two parallel slots 41, two rings 40, one ring for each of two consecutive rolls of the log 100 are obtained. figure 8 shows a ring 50 'with slots 51 parallel to the axis which give two rings 50 after sawing across the slots 51.

On the figure 9 another embodiment of the ring with extraction means is shown. The ring 60 is made of corrugated cardboard, material in itself well known. The ring thus comprises a corrugated layer 61 between an inner layer 62 and an outer layer 63. The inner layer 62 constitutes the extraction means of the invention. Indeed, when the ring is in place in the central hole of the roll, the corrugated layer supports the pressure forces of the roll, leaving the inner layer 62 subjected to a relatively lower pressure. Moreover, the inner layer is disengaged from the inner surface of the roller thereby allowing it to be grasped by the fingers.

The figure 10 shows another ring variant that can be used in accordance with the invention. Here the ring 70 is formed of a spiral winding, with overlapping turns 71 over a certain thickness. Of this way as in the previous case can be grasped easily the inner end 72 of the winding.

On the figure 11 another embodiment of the invention is shown. The ring 80 inside the central hole of the roll 10 is formed of at least two layers of cardboard. The radially outer layer 81, on the side of the tissue paper, is made of cardboard or kraft paper relatively light weight, from 80 g / m ² to 180 g / m ² . The radially inner layer or layers 82, are heavier weight, 500 g / m ² . The ring is made as a roll mandrel known per se. One or more strand forming strips are helically wound around a cylindrical shape; the turns of a strand are contiguous or substantially contiguous along a helical line 80 '. Preferably, the high-weight web is partially glued to permit release after saw cutting of a portion of the winding tip. This point 83 advantageously forms a pull tab of the ring before putting the roll into service.

The detachment of the radially inner layer 82 makes it possible to cause the radially outer layer 81 to yield by pressure and to release the ring completely. Upon extraction thereof, the first sheet of tissue paper adhered to the layer 81 is driven therewith.

We have shown on the figure 13 , an embodiment of the rings with two superposed layers, one internal 82, the other external 81. Two strips of cardboard 181 and 182 or other material, are wound helically around a cylindrical pin 100. The angle alpha of the helix relative to the axis of pin 100 is the same for both bands. It is chosen so that the turns of the outer band 181 are contiguous or substantially contiguous. The width of the inner band 182 is greater than that of the outer band 181. It follows a partial overlap of the turns of the inner band 182. By gluing the inside of the outer band 181, the two layers thus formed are secured. However, the overlap zone 182 'of the turns of the inner band is not glued. The rings obtained after cutting the tube formed by the two strips have inside, an unglued portion 182 'This part forms the gripping tab. This is an exemplary embodiment of a non-glued area to form a gripping means. This example is not limiting.

On the figure 12 , the embodiment consists of a ring 90 housed in the central hole of the roll 10, on which axial markings 90F have been made, such as grooves, which at the time of cutting by the saw cause the deformation of the ring 90 under the pressure of the latter. These grooves are parallel to the axis of the roll and preferably formed on the outer face of the ring. The number of grooves is sufficient, especially six, so that the saw always supports near a marking line regardless of the angular position of the ring. The ring thus deformed has a tip or a spoiler 91 with an edge formed of the marking 90F constituting an easy grip for extraction. The ring 90 is advantageously formed like the previous ones of a single or multiple band wound in a spiral.

The invention is not limited to the embodiments described, it encompasses all variants within the scope of those skilled in the art and covered by the claims.

Claims (23)

1. Roll (10) of paper, in particular of tissue paper, comprising a central hole along its winding axis with a cylindrical reinforcing element on which the paper is wound, characterized in that said reinforcing element comprises at least one ring (40, 50, 60, 70; 80; 90) attached to the innermost turn of the roll (10), with a width less than the width of the roll and provided with a means of extracting the ring by pulling substantially along the axis of the roll.
2. Roll according to Claim 1, the ring (40; 50) of which includes at least one slot (41; 51) that makes it possible, from the outer edge of the ring, to fold the material forming the ring (40; 50) towards the axis of the roll and so provide a grasping tab forming said extraction means.
3. Roll according to the preceding claim, the slot (41) of which follows the curvature of the ring (40) and is in particular in arc-of-circle form.
4. Roll according to Claim 2, the slot (51) of which is axially oriented.
5. Roll according to the preceding claim, the slot (51) of which extends from an edge of the ring (50) over a part of the width of said ring.
6. Roll according to Claim 3, 4 or 5, comprising two slots (41; 51).
7. Roll according to Claim 1, the ring of which is flush with or slightly set back from one end of the roll (14).
8. Roll according to Claim 1, the ring (70; 80) of which comprises at least two layers with an outer layer in contact with the sheet of paper and an inner layer towards the axis of the roll, with a means of extracting the inner layer.
9. Roll according to Claim 8, of which the outer layer and the inner layer are glued to one another, a part of the inner layer in contact with the outer layer not being glued to the outer layer and forming the means of extracting the inner layer.
10. Roll according to Claim 8, the ring (80) of which comprises at least two layers with an outer layer in contact with the sheet of paper and an inner layer toward the axis of the roll, the two layers being formed by helical turns, the turns of the inner layer partially overlapping and not being linked in the overlap area.
11. Roll according to Claim 9, of which the turns of the outer layer and the turns of the inner layer are wound at one and the same winding angle and the turns of the inner layer have a width greater than that of the turns of the outer layer so as to create said overlap.
12. Roll according to the preceding claim, of which the turns of the outer layer are adjoining.
13. Roll according to Claim 8, the ring (60) of which is made of corrugated cardboard with a corrugated layer (61) between two non-corrugated layers (62, 63).
14. Roll according to Claim 1, the ring (90) of which has an area deformed by displacement towards the axis of the roll so as to form a grasping lug (91).
15. Roll according to any one of Claims 1 to 14, the ring of which is secured by gluing or by mechanical bonding to at least said innermost turn of the roll (10).
16. Roll according to any one of the preceding claims, the ring (40; 50; 60; 70; 80; 90) of which presents a width less than half the width of the roll (10), preferably less than a third of the width of the roll and more particularly less than a quarter of the width of the roll.
17. Roll according to the preceding claim, of which the width of the ring is at least equal to a seventh of the width of the roll.
18. Roll according to any one of the preceding claims, comprising a second ring in the central hole axially offset relative to the first ring, secured in position without gluing.
19. Use of a roll according to one of the preceding claims in a paper dispensing system with central unwinding.
20. Method of manufacturing a roll according to one of Claims 1 to 17, comprising the fitting on a spindle of hoops (40'; 50') arranged to, after transverse cutting forming two of said rings, provide an extraction means on each of said rings, the winding of a wide sheet onto the spindle, the extraction of the spindle and the cutting of the log obtained through said hoops so as to obtain rolls with said rings.
21. Method according to Claim 20, whereby the hoops are fixed temporarily in rotation and in translation onto the spindle.
22. Method according to the preceding claim, whereby the hoops are fixed temporarily onto the spindle by a mechanical means, notably by clamping.
23. Method of manufacturing a roll according to one of Claims 1 to 17, comprising the fitting of the ring or rings in the hole provided in the roll.

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