EP2142060A1

EP2142060A1 - Roll of fibrous cellulose-based product

Info

Publication number: EP2142060A1
Application number: EP08788057A
Authority: EP
Inventors: Donald Barredo
Original assignee: Georgia Pacific France SAS
Current assignee: Essity Operations France SAS
Priority date: 2007-03-28
Filing date: 2008-03-27
Publication date: 2010-01-13
Anticipated expiration: 2028-03-27
Also published as: US8383223B2; ES2929282T3; PL3590400T3; HUE046430T2; HUE060408T2; US20100112264A1; ES2755738T3; PL2142060T3; PT2142060T; MX2009010259A; EA200901306A1; WO2008135690A1; CA2682218A1; EP3590400A1; FI3590400T3; FR2914170B1; EP4029420A1; FR2914170A1; EP3590400B1; PT3590400T

Abstract

The present invention relates to the field of cellulose wadding products for sanitary or domestic use and in particular to products in roll form, such as rolls of toilet paper (or hygiene paper) and the like. The subject of the invention is a roll of fibrous cellulose-based product, characterized in that it comprises a wound web of cellulose wadding sheets (2) separated by perforated or prescored lines (4), the individual plies (3) of each sheet (2) being bonded to a peripheral surface (5) comprising between 4% and 60% of the total area of each sheet (2).

Description

Roll of fibrous cellulosic product

The present invention relates to the field of cellulose wadding products for sanitary or domestic use and is intended in particular products in rolls such as rolls of toilet paper (or toilet paper) and the like. It relates to a roll composed of articles based on one (or essentially made of) fibrous cellulosic product. More particularly and according to a preferred embodiment, it relates to a roller, some of which leaves, and even more preferably of which each sheet which composes it, has a single single pattern entirely comprised in the format of said one or more sheets, it is that is, not cut by one or more of the four edges that delimit the sheet (usually of shape or rectangular surface).

In general, products of the abovementioned type, which are packaged in the form of rolls, are already known. In these rolls, the product sheets to be dispensed are usually wound on a central mandrel of cylindrical section of cardboard or the like. In the field concerned, said rolled sheets of interest to the user are conventionally made from cellulosic fibrous products (or mainly cellulose) cellulose and assembled in the form of one or more superposed linked folds (layered products or the like). "Sandwich") which follow one after the other on the roll, said sheets being separated from each other, in the direction perpendicular to the direction of unwinding of the sheets by perforated or pre-cut lines making it possible to tear off or detach a or several sheets of the roll. In the case of rolls of multiply sheets, the different folds of the same size superimposed are, depending on the intended use of the sheet and / or the requirements imposed by the consumer's wishes and / or the constraints of production techniques, more or less strongly related to each other by using different techniques of assembly of said folds. Most often, the combination of folds in a product multiplied essentially in cellulose wadding is achieved by applying an adhesive between said plies. Said bonding is carried out by means of any adhesive product generally used in the field of sanitary and domestic papers to associate folds with each other such as, for example, an alcohol polyvinyl solution in an aqueous medium. This association by gluing can be combined with another type, just as classic, of association of folds which is purely mechanical and which consists in locally deforming, by crushing, folds to bind so that the latter, nested in each other under the pressure of a cylinder, are held together once the association operation is complete.

In the case of gluing, the glue had until now been uniformly deposited over the entire surface of the folds of the wound product. However, the removal of the adhesive being associated with the embossing pattern, this requires an embossing pattern that covers the entire surface of the product.

The patterns currently used are therefore of relatively small size and repeated a number of times in the direction and direction of each sheet, usually with at least two similar or identical patterns per sheet of paper, for example toilet paper. This creates a continuous succession of embossed patterns all along the successive sheets when unrolling the roll product, said patterns being cut more or less randomly when they meet one of the side edges of the ribbon formed by the succession of sheets hung together when they are rolled in the direction and when they meet a transverse edge which is formed in the cross direction when the user detaches a sheet of the roll and / or two sheets that follow. This is particularly critical and unsightly when the patterns are relatively large at their surface relative to the dimensions of the sheet since these cuts break the pattern and may, because of the geometric shape of certain patterns, reveal weakened areas where the The bonds are, by reason of the cutting of said motif, weakened compared to what would be the case in a whole uncut motive.

Another disadvantage related to the type of bonding association referred to above is a stiffening of the paper sheet (because of the glue) and therefore a more difficult and more difficult winding. Furthermore, with an embossing-type mechanical treatment, there is an "upside-down" effect due to the protuberances, especially in the area of use, ie in the central zone of the paper sheet and an accelerated piercing. by a liquid of said paper by a so-called "tent" effect at the aforementioned association protuberances. Finally, the resistance at the level of the embossing patterns is weakened in the area of use due in particular to the destruction of the fibers.

These disadvantages are particularly important when the wrapped paper is toilet paper or the like of which the main qualities sought are above all the flexibility, softness, resistance to tearing (especially in the wet state) and the aesthetic appearance.

There is therefore a real need to be able to offer the consumer a roll of paper of this type which combines both a presentable aesthetic, preferably original and modifiable at will properties of resistance, flexibility and softness at least equivalent to those known coiled products where the patterns are repeated at very high frequencies and which are cut at the edges of the sheets in the wound or detached state of said roll. The present invention aims to overcome at least some of these disadvantages.

To this end, it proposes a new association scheme which, in a roll pack product, uses the standard configuration with a new arrangement of bonding and association points. Indeed, in order to obtain a zone of use that is as comfortable and efficient as possible for the user, said association points have been moved towards the periphery of the product, that is to say from the sheet and preferably from each sheet present on said roll. Two different zones are then created per sheet: a so-called "technical" or peripheral zone extending from the edges in the direction of travel and / or across and going towards the inside of the sheet and a so-called "use" zone located at center level of the product unit (a sheet).

Said technical zone, which can group several portions of disjoint zones (which also start from one or more edges towards the center of the sheet) serves mainly to ensure the combination of the folds and confers a certain desired peripheral rigidity, in particular by the consumer himself. The surface of the technical zone thus varies between a lower limit corresponding to a sufficient resistance to delamination and an upper limit where the product would become too rigid. Said use zone which can also group several portions of disjunct zones (at or near the center of the sheet) serves mainly to impart softness, thickness, flexibility, a barrier effect (diffusion) and / or resistance (for example to piercing).

The set of surfaces of the two aforementioned zones or the joining of the surfaces of all the partial technical and use areas which are complementary forms the total surface of the unit sheet whose succession is rolled up.

The subject of the present invention is therefore a roll of sheets based on a fibrous cellulosic product, such as toilet paper, comprising a wound strip consisting of a continuous succession of sheets made of cellulose wadding made by association with at least two individual plies, each sheet being retained, with detachment capability, with the one or both adjacent sheets by one, respectively two pre-cut lines, characterized in that said at least two individual plies of each sheet are bonded by gluing or by mechanical pressure along a peripheral zone of each sheet and in that the surface of said peripheral zone represents between 4% and 60% of the total area of each sheet.

According to a particularly preferred embodiment, the invention also relates to a roller characterized in that at least one sheet, preferably each sheet, has in its central zone not forming part of the peripheral zone, at least one pattern made by embossing and / or dry marking.

The invention will be better understood, thanks to the following description, which refers to preferred embodiments, given by way of non-limiting examples, and explained with reference to the appended diagrammatic drawings, in which: FIG. , schematically, a first example of a roll of sheets according to the invention; FIG. 2 schematically represents an enlarged view showing more precisely, and seen from above, an extract of a second example of a roll of sheets according to the invention; Figure 3 schematically shows an enlarged view, and seen from above, of a multiplied sheet of a product A not according to the invention and given as a comparative example; and FIG. 4 schematically represents an enlarged view, seen from above, of a multiplied sheet of a product B according to the invention. With reference to FIGS. 1 and 2, the subject of the present invention is thus a roll 1 of sheets 2 based on a fibrous cellulosic product, such as toilet paper, comprising a wound strip consisting of a continuous succession of sheets 2 to cellulose wadding base made by combining at least two individual plies 3, each sheet 2 being retained, with the ability to detach, with the adjacent sheet or sheets 2 by one or respectively two precut lines 4, characterized in that said at least two individual plies 3 of each sheet 2 are bonded by bonding or mechanical pressure along a peripheral zone 5 of each sheet 2 and in that the surface of said peripheral zone 5 represents between 4% and 60% of the total area of each sheet 2.

According to one variant, the above-mentioned surface represents between 50% (excluded) and 60% (inclusive) of the total area of each sheet 2. Preferably, the bonding between said at least two individual plies 3 of each sheet 2 is carried out by gluing.

A sheet 2 consists of at least two superposed individual plies 3, generally of the same size and of the same rectangular or even square shape, the standard dimensions of which usually vary between 90 mm and 140 mm for the length (ie in the direction of travel SM , that is to say parallel to the direction of travel of the wound product) and between 80 mm and 110 mm for the width (thus in the transverse direction ST, that is to say perpendicular to the direction of travel of the wound product ). In order to guarantee sufficient cohesion of the sheet 2 and to avoid any delamination of the latter, it will advantageously be possible to provide a connection of the plies 3 such that the resistance to delamination between each individual ply 3 is at least 1 g / cm.

For clarity, the individual individual plies 3 superimposed have not been shown in the accompanying figures. In the context of the present invention, it is assumed that the example shown comprises five rectangular superimposed folds of the same size (14 cm × 11 cm), the fold 3 represented in the appended figures being that located on the external face (visible to the user ) of the roll 1 according to the invention.

The other plies (not shown) may be single plies provided all over their face with a uniform and continuous uniform micro-embossing consisting of standard protuberances with a density of at least 20 protuberances / cm ² , preferably because of a density between 30 and 100 protuberances / cm ² . The plies 3, for example six in number, may be interconnected by peripheral gluing, for example gluing obtained by applying glue to a conventional embossing consisting of protuberances whose vertices are circular in shape of a diameter. between 0.1 mm and 1.5 mm, preferably between 0.6 mm and 1.1 mm distributed homogeneously according to a density of protuberances between 5 protuberances / cm ² and 80 protuberances / cm ² , preferably between 5 protuberances / cm and 30 protuberances / cm.

Alternatively, the bonding may be carried out by applying an adhesive on any embossing pattern but located in the peripheral zone 5, for example that resulting from the particular embossing shown in more detail in FIG. 2 for another example of a roll 1 according to FIG. 'invention. A preferred method of bonding is that described in the French patent published under No. FR-A-2,653,793 which ensures a uniform glue deposit in the bonding zone without stiffening the sheet.

Without departing from the scope of the present invention, the connection between said at least two individual plies 3 of each sheet 2 can be achieved by any mechanical connection known to those skilled in the art allowing to associate in a purely physical way at least two plies 3 between them, for example by mechanical pressure, embossing, knurling, etc.

The number of individual plies 3 forming each sheet 2 may be between two and ten and preferably between four and seven individual plies.

The plies 3 are normally made of cellulose wadding (pure or majority) with a grammage of between 10 g / m and 50 g / m 2 and may include the additives conventionally used in this field insofar as the latter do not interfere. critically with the other technical features of the invention. The grammages and the nature of the plies 3 may vary from one ply 3 to the other but are preferably the same or substantially the same for all the plies 3 or for a large part of the plies 3. The grammage of each sheet 2 is included between 30 g / m ² and 150 g / m ² , preferably between 85 g / m ² and 115 g / m ² .

According to a first aspect of the invention, the roll 1 according to the invention is characterized in that all of the bonding surfaces between said plies 3 of at least one sheet 2, preferably of each sheet 2 is smaller than the surface covered by said peripheral zone 5. In a particularly preferred manner, the connecting surface between said plies 3 of at least one sheet 2, preferably each sheet 2, is between 1% and 50%, preferably between 3% and 7% of the total area covered by said peripheral zone 5.

Thus, it avoids too much stiffness of the sheet 2, and in a new and unexpected way is obtained a roll 1 formed of flexible sheets 2.

The connecting surface has been adjusted so as to preserve the flexibility of the strip of the roll 1 formed by the succession of sheets 2 when they are still attached to each other, in particular to ensure a good winding of said sheets 2 while keeping a good resistance to the delamination of the latter.

By peripheral zone 5 is meant the zone starting from one or more or even all four edges or ends of the surface defining the sheet 2 (including or including them) and extending towards the center of said sheet 2. This avoids any yawn folds 3 or the formation of folds that adversely affect the appearance of the product. An example of a simple geometry of this peripheral zone 5 is a continuous rectilinear strip of constant thickness all around said rectangular sheet 2. Of course, the shape of said peripheral zone 5 may be irregular and / or discontinuous and / or curvilinear, etc., as long as it can define a surface in which the association between the plies 3 to be bonded takes place and that it is located on the outskirts of sheet 2.

Advantageously, the roll 1 according to the invention consists of relatively "thick" sheets 2 which, while keeping good softness, curl perfectly to form a roll 1. According to a preferred embodiment, the roll 1 according to the invention is characterized in that the connection between said at least two individual plies 3 of each sheet 2 is made around the entire periphery of at least one sheet 2, preferably each sheet 2.

Advantageously, the connection between said at least two individual plies 3 of each sheet 2 is made in said peripheral zone 5 in a discontinuous manner, preferably by connection points 6 and / or by straight lines or portions of straight lines 7 and / or by connecting line (s) curve (s) 7 '.

As shown in FIGS. 1 and 2, the roller 1 according to the invention is, in a particular glued example, characterized in that the adhesive is deposited in said peripheral zone 5 in a discontinuous manner, here by connection points 6, so bonding points (of form round or substantially round) distributed in said peripheral zone 5. For the sake of clarity only part of the bonding or bonding points 6 has been shown in FIG. 2, the other bonding or bonding points 6 being suggested by dots . Also for the sake of clarity, the existence of the neighboring sheets 2 to the left and to the right of the sheet 2 shown in FIG. 2 has only been suggested by the drawing of the general outline without representing the details of these sheets 2 which are identical to that shown in detail in the center of Figure 2.

Advantageously, and in the most general case with regard to the association of the various plies 3, the above-mentioned connection points 6 are located on at least one connecting straight line portion 7 originating from one or more of the four corners of at least one sheet 2, preferably each sheet 2, and directed towards the inside or the edge adjacent said corner of said sheet or sheets 2. In another aspect, the right portion or portions link 7 are not parallel to the sides defining the length and / or the width of a sheet 2, preferably each sheet 2.

It is thus possible to draw portions of straight connecting lines 7 evoking sun rays which radiate from one or all of the four corners of the sheet 2.

According to a variant, the roll 1 according to the invention is further characterized in that the connection points 6 are located on at least one curved connecting line 7 'in an arc of circle whose two ends are situated on one and the same edge. one or each sheet 2 and the concavity of which is directed towards the interior of said sheet or sheets 2. Such curved connecting lines 7 'have also been suggested in FIG. 2.

Advantageously, the spacing between the adjacent connection points 6 of the same portion of straight line 7 or curve T is not uniform, on at least one sheet 2, preferably on each sheet 2.

As can be seen in FIG. 2, the distance between two adjacent connection points 6 situated on the same connecting straight line 7 may vary and, as shown, for example be reduced as one approaches the center of the sheet 2. This makes it possible to create aesthetic effects and to play on the density of connection points 6 in the peripheral zone 5. Indeed, by decreasing the area of association at the peripheral zone 5 is increased, by constant embossing, the pressure applied locally to the fold 3 and thus the penetration of the adhesive in the various folds 3 superimposed to assemble. According to one variant, provision can be made for the spacing of the connection points 6 to be uniform on at least one sheet 2, preferably on each sheet 2.

According to a particularly preferred embodiment, the roll 1 according to the invention is characterized in that at least one sheet 2, preferably each sheet 2, has in its central zone 8 not forming part of the peripheral zone 5, at least one pattern 9 made by embossing and / or dry marking.

Advantageously, the pattern or patterns 9 are in the form of line (s) and / or point (s) of patterns 9 '. In a preferred manner, the pattern (s) 9 are in the form of at least one homogeneously embossed closed surface at the rate of an overall density of pattern points 9 'in the form of protuberances due to the embossment between 20 protuberances / cm ² and 100 protuberances / cm ² , preferably between 60 protuberances / cm ² and 100 protuberances / cm, the diameter of the circular section vertices of the protuberances being between 0.1 mm and 1.5 mm, preferably between 0 , 3 mm and 0.6 mm.

In the examples illustrated in FIGS. 1 and 2, the pattern 9 is a specific square geometrical shape or an embossed oval with conventional round protuberances.

Most preferably, the roll 1 according to the invention is characterized in that at least one sheet 2, preferably each sheet 2, comprises a single and unique pattern 9 entirely included in the surface not belonging to the zone device 5 of sheet 2 or each sheet 2.

In contrast to the repetitive patterns known, there is therefore no risk here that a pattern 9, preferably centered on the sheet 2, is cut by a lateral edge or an edge defined by a pre-cut line 4.

In this connection, it should be noted that the term pre-cut line 4 also includes non-rectilinear boundaries (for example waves) even though straight 4 pre-cut lines are widely preferred. These lines are classic and formed by all techniques known and usually employed by those skilled in the art, for example by stamping or cutting with appropriate blades in an ad hoc device at the winding head where the rollers are formed. The precut can be done according to perforations in the form of dotted (round) or dashes (segments).

According to another characteristic, there is, between the contour (s) 10 of the pattern (s) 9 and the contours 11 delimiting the peripheral zone 5, at least one free zone 12 having no embossing, dry marking or other distinctive sign. This reinforces the contrast between said pattern 9 and the rest of the fold 3.

According to a variant, the pattern (s) 9 comprise one or more digits and / or one or more letters.

It is thus possible to mark and personalize the product in roll with any message, an advertising slogan, the name (trademark of the product) or the like.

In a particularly interesting way, it is possible for the total number of different types of patterns 9 present on the same complete roll 1 to be an integer between 1 and 25, preferably between 1 and 6. In this way, it is possible to provide several different types of patterns 9 simultaneously present on the same roll 1, always one reason per sheet 2.

The present invention is also characterized in that said roll 1 comprises at least one sheet 2 having in its central zone 8, not forming part of the peripheral zone 5, no pattern 9 made by embossing and / or dry marking. It is thus possible to leave one or more blank sheets 2 at their central zones 8, which makes it possible to increase the number of combinations of products that can be obtained.

Advantageously, the sheets 2 having a pattern 9 alternate with leaves 2 having no pattern 9.

Preferably, the alternation consists of the succession of a sheet 2 provided with a pattern 9 with exactly one sheet 2 not provided with a pattern 9, etc.

To produce a product according to the invention, any conventional installation known in the paper industry can be used. In such a conventional plant two main plies 3 of cellulose wadding, one and / or the other may be laminates multiplis, from their The respective reels are guided to pass around two rubber cylinders and then between them and two steel embossing cylinders provided with appropriate reliefs. These reliefs may, for example, be distributed according to the patterns visible in FIGS. 1 and 2. One of the two aforementioned plies 3 is glued by means of a gluing roll (or applicator roll) made of rubber which comprises a part made of relief whose design corresponds to that of the peripheral area 5 sizing sheets 2 so that the glue driven by the applicator cylinder is distributed in this pattern. It is possible to emboss one or both sheets 2 over their entire surface. Gluing is performed only on the peripheral zone 5 corresponding to the raised part of the sizing cylinder. In another embodiment, one or both of the cylinders are provided with reliefs along a peripheral zone 5 of the desired roll product format. We can then use a smooth gluing cylinder. After sizing, the two main plies 3 are assembled in the nip between the embossing cylinders which rotate at equal speeds and opposite directions.

According to a variant, a single or multiple ply 3 is waffled between a rubber cylinder and a suitably etched steel cylinder, that is to say with reliefs along the periphery of the desired product format. The adhesive is deposited on the summits of the reliefs. Finally, it is applied to the fold 3 a second, respectively third fold 3 by means of a third rubber marrying type cylinder. The second and third plies 3 can also be embossed before their association. This third cylinder thus ensures the association of the second and third fold 3 respectively with the first. For the third cylinder can also be used a steel cylinder.

The sheet 2 multiplied thus resulting from the manufacturing device is driven to a winder head where it is optionally cut to the desired format and where the pre-cut lines 4 are formed at regular intervals in the strip of sheets 2 by an appropriate device of prior to winding the product in the form of the roll 1. Tests: Tests were carried out to verify the technical effectiveness of the invention with respect to another roll product given by way of comparative example. A first roll product A of which a detached sheet 2 has been schematically shown in FIG. 3 consists of six plies of pure cellulose wadding each having a basis weight of 18.7 g / m ² . This product A was obtained by combining said plies 3 by an embossing / bonding with Forbo SWFT L998 / 4 adhesive according to the pattern shown in FIG. 3 where the embossing / gluing is carried out by the connection points 6, namely, bonding in the form of large protuberances 6 and distributed over a large part of the sheet 2 and mainly in the central zone 8 of the latter. The four zones simply embossed (without gluing), for example by a conventional micro-embossing, are located at the four corners of said sheet 2. In these areas the embossing is of the type constituting the pattern 9 in FIGS. 2, that is to say consisting of pattern points 9 '. All other sheets 2 (not shown) of the roll 1 of product A are made in the same way. The latter was compared with a product B according to the invention consisting of the same plies as the product A but according to an association of said plies by an embossing / bonding according to the invention. The folds 3 of the sheet 2 of the product B have been associated in the pattern shown in FIG. 4 (which also represents a sheet 2 detached from the roll 1) where the embossing / gluing is carried out by the connection points 6, namely gluing points in the form of large protuberances 6 and distributed only on the peripheral zone 5 of the sheet 2. The simply embossed zone (without gluing) is located at the central zone 8 of said sheet 2. In this single zone the embossing is of the type constituting the pattern 9 in Figures 1 and 2, that is to say consisting of pattern points 9 '. All other sheets 2 (not shown) of the roll 1 of product B are also made in the same way.

The results of the different comparative tests are given below.

Dry resistances in N / m according to standard NF EN 12625-4:

SM resistance ST resistance

Product A 656 289

Product B

(invention) 791,310 At configuration settings and identical starting fabric, there is a clear improvement in strength with an embossing / association only periphery of the product.

There is a 20% improvement in the resistance in the running direction and 7% in the resistance in the cross direction.

In addition, it has been found during tensile tests that the non-associated central zone 8 offers the best protection for the user. Indeed, the first folds 3 to yield are in central folds, while with the associated use zone, the first folds 3 that break are those from the outside.

Barrier effect (diffusion):

A penetration test was carried out on the two previous products A and B:

The test consists in homogeneously distributing drops of ten microliters of distilled water in the central zone 8 of use and in checking whether these drops or not pass through the product.

With the product B according to the invention only 9% of the drops pass through, unlike a conventional embossing / association (product A) where 100% of the drops pass through.

Flexibility:

The flexibility of the format, expressed in N, is determined by the so-called "Ring & Rod" method which consists in passing a sheet of a given surface through a hole of diameter slightly greater than the large diameter of a truncated cone surrounded by the sheet. The tensile force on the sheet (in N) is measured before and during its passage through the hole (in mm). When passing through the hole, the slope of the curve changes and the value of the force is measured at the point of inflection. We obtained for the two products mentioned above:

Product A: 215 +/- 20C cN Product B (according to the invention): 175 +/- 15 cN There is therefore an improvement in the order of 23% of the flexibility compared to a known product.

Sweetness:

Product A: backside effect, even minimal Product B: no back-up effect as there are no sticky pins.

Comparative consumer tests have been carried out between the product B according to the invention and known products, for example of the trademark "MOLTONEL" (registered trademark), tests according to which a clear improvement has been recognized with regard to both the softness, thickness and economy. The benefit that comes first is relative to softness, then comes the thickness and then the economy of use. It is the simultaneity and the synergy of these three characteristics which confer on the invention both its novelty and its inventiveness.

Of course, the invention is not limited to the embodiments described and shown in the accompanying drawings. Modifications are possible, particularly from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

1. Roll (1) of sheets (2) based on a fibrous cellulosic product, such as toilet paper, comprising a wound strip consisting of a continuous succession of sheets (2) based on cellulose wadding made by association at least two individual plies (3), each sheet (2) being detachably retained with the adjacent one or both sheets (2) by one or two precut lines (4), respectively said at least two individual plies (3) of each sheet (2) being bonded by bonding or mechanical pressure along a peripheral area (5) of each sheet (2) and the area of said peripheral area (5) representing between 4% and 60% of the total area of each sheet (2), characterized in that the connection between said at least two individual plies (3) of each sheet (2) is made all around at least one sheet (2) preferably each sheet (2).

2. Roller (1) according to claim 1, characterized in that all of the bonding surfaces between said folds (3) of at least one sheet

(2), preferably each sheet (2) is smaller than the area covered by said peripheral area (5).

3. Roller (1) according to any one of claims 1 or 2, characterized in that the connection between said at least two folds (3) of each individual sheet (2) is made in said peripheral zone (5) so discontinuous, preferably by connecting points (6) and / or straight lines or portions of connecting lines (7) and / or by line connection (s) curved (s) (7 ').

4. Roller (1) according to one of the preceding claims, characterized in that at least one sheet (2), preferably each sheet

(2), has in its central zone (8) not part of the peripheral zone (5), at least one pattern (9) made by embossing and / or dry marking.

5. Roller (1) according to claim 4, characterized in that the pattern or patterns (9) are in the form of line (s) and / or point (s) of patterns (9 ').

6. Roller (1) according to any one of claims 4 or 5, characterized in that at least one sheet (2), preferably each sheet (2), comprises a single pattern (9) fully included in the surface not belonging to the peripheral zone (5) of the sheet (2) or of each sheet (2).

7. Roller (1) according to any one of claims 4 to 6, characterized in that there is between the contour (s) (10) of the pattern or patterns (9) and the contours (11) delimiting the peripheral zone. (5), at least one free zone (12) having no embossing, dry marking or other distinctive sign.

8. Roller (1) according to any one of claims 4 to 7, characterized in that the total number of different types of patterns (9) present on the same roll (1) complete is an integer between 1 and 25 preferably between 1 and 6.

9. Roller (1) according to any one of claims 1 to 3, characterized in that it comprises at least one sheet (2) having in its central zone (8) not forming part of the peripheral zone (5) no pattern (9) made by embossing and / or dry marking.

10. Roller (1) according to any one of claims 4 to 8 and according to claim 10, characterized in that the sheets (2) having a pattern (9) alternate with leaves (2) having no pattern ( 9).

11. Roller (1) according to any one of claims 1 to

10, characterized in that the bonding surface between said plies (3) of at least one sheet (2), preferably of each sheet (2), is between 1% and 50%, preferably between 3% and 7% of the total area covered by the peripheral area (5).

Roller (1) according to any one of claims 1 to

11, characterized in that the number of individual folds (3) forming each sheet (2) is between 2 and 10 and preferably between 4 and 7 individual folds (3).

13. Roller (1) according to any one of claims 1 to 12, characterized in that the basis weight of each sheet (2) is between 30 g / m ² and 150 g / m ² , preferably between 85 g / m ² and 115 g / m ² .

14. Roller (1) according to any one of claims 1 to 13, characterized in that the connection between said at least two plies (3) of each individual sheet (2) is made by gluing.