A multi-use paper product and device for the production thereof

DESCRIPTION Technical field

The present invention relates to improvements to paper products, in particular tissue paper, especially to products composed of a continuous web material wound in rolls.

The invention also relates to a device for the production of this type of article.

State of the art Tissue or crepe paper is utilized with increasing frequency to produce a plurality of different articles for domestic and family use.

According to the type of use made of them, articles are produced and packaged in different ways. For example, napkins and handkerchiefs are produced with folded sheets and packaged in packs. Other articles, such as kitchen towels, are made up in the form of rolls. These rolls are composed of a continuous web material divided into single sheets, which are torn off along a perforation line at the time of use. Rolls of kitchen towel are usually inserted in dispensers, which facilitate their use. Object and summary of the invention An object of the present invention is to produce a paper product or article, in particular tissue paper, which can be used for a plurality of purposes especially in the domestic and family sphere.

In substance, the invention provides for a continuous paper web product wound in a roll, with two longitudinal edges and a plurality of transverse perforation lines, which divide the web material into detachable sheets, characterized by having at least one intermediate longitudinal line to facilitate folding or weakening line, between said two longitudinal edges. Longitudinal line is intended in general as a line, which has an orientation at least in part in the direction of length of the web material wound in the roll. Therefore, the line to facilitate folding or weakening line can be a longitudinal line parallel or substantially parallel to the longitudinal edges of the wound web material, or a longitudinal line extending diagonally, i.e. approximately coincident with one of the diagonals of the detachable sheet that normally has a quadrangular extension (typically square or rectangular). It would also be

_ possible to provide more than one line to facilitate folding or weakening line, approximately parallel to the longitudinal edges or diagonally, for example along the two intersecting diagonals of the quadrangular sheet of detachable web material. As will be apparent from some examples of embodiment described in greater detail hereunder, this positioning of perforation lines and lines to facilitate folding or weakening lines allows the product in roll form to be used as a normal kitchen towel or to obtain folded napkins. The latter are obtained by detaching a portion of material in sheet form from the roll and folding it into several parts longitudinally and/or transversely, i.e. along a perforation line or (in a possible modified embodiment of the invention) a score line interposed between two consecutive perforation and tearing lines. Lines to facilitate folding or weakening lines are intended in general as a preferential folding line, such as a score line, a mechanical ply-bonding line or a perforation line. In particular, when the line in question is a perforation line, it also produces a weakening of the fibrous structure of the web material, along which the fold can be made due to folding being facilitated by the perforation line, or along which the material can also be torn off, due to the weakening effect of the perforations. If the web material only has transverse perforation lines and no score lines interposed therebetween, the napkin can also be obtained with two adjacent portions, defined between two consecutive perforation lines, and folded in half along the longitudinal weakening line or line to facilitate folding. In this case a napkin folded in two rather than in four is obtained. According to a particularly advantageous possible embodiment of the invention, the product has a surface design, obtained by printing, by embossing, with a combination of printing and embossing or in any other suitable way. The consecutive perforation lines define, with said intermediate longitudinal line, areas with designs preferably separated from one another. This allows the napkin composed of several portions of sheet material, to be folded according in various ways, leaving one or other of the various designs provided on the product in view. It would also be possible for the two sides of the napkin to be decorated with different designs, to double the choices of the final user.

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The intermediate longitudinal weakening line or line to facilitate folding can be a line of longitudinal perforation, or a score or mechanical ply-bonding line, or in any case a line to weaken the paper fibers, obtained by action on said paper fibers of which the product is composed, the result of which is to produce an area in which folding of the article is facilitated. As already mentioned, the line can in any case extend in a strictly longitudinal direction, i.e. substantially parallel to the edges of the wound material, or can have an inclined orientation, i.e. approximately parallel to a diagonal of the detachable sheet. As already mentioned, the product can be divided into a plurality of sheets by transverse perforation lines. In the case of a napkin folded in four, when the product only has transverse perforation lines, and has no transverse score lines, the napkin is obtained by detaching four portions of paper material from the roll, included between a first and a third transverse perforation line. The four portions are then folded in four into a napkin along the intermediate perforation line between the two lines along which the material was torn off and along the intermediate longitudinal line. Alternatively, the napkin can be folded in two halves only and is obtained by detaching from the roll two portions of paper material delimited by a first and a second transverse perforation line. The two portions are then folded in half along only the intermediate longitudinal line.

In a modified embodiment of the invention, a transverse score line is positioned between two consecutive transverse perforation lines. In this case, when one wishes to obtain a napkin, a portion delimited between two transverse perforation lines, and containing an intermediate transverse score line besides the longitudinal line to facilitate folding, is detached from the roll. Alternatively, if a perforation line is present longitudinally, the napkin is obtained by tearing the paper along half of a transverse perforation line and along the longitudinal perforation line and folding the torn off paper obtained in two along the transverse score line. Alternatively, between two perforation lines defining the detachable sheet, a further perforation line with greater tensile strength can be produced, which in this case forms a transverse line to facilitate folding.

In a further embodiment, the individual roll can have more than one

_ _ longitudinal score line; in the case of two lines, these can be parallel to each other and to the edges of the paper material and be used to longitudinally fold the portion torn from the roll, to form a napkin folded in three or (particularly if there is also a transverse score line, a weakening line or a line to facilitate folding defined in another way) six parts, possibly all of the same size.

Preferably, the product is composed of a plurality of plies bonded together, e.g. two or more plies preferably glued to one another. The plies are advantageously plies of tissue paper with a grammage suitable to obtain a product with an overall grammage ranging from 20 to 90 g/m ² . According to a different aspect, the invention relates to a rewinding machine for producing rolls of wound web material, comprising: a winding unit; a feed path of the web material towards said winding unit; along said feed path a perforator unit to produce transverse perforation lines on the web material. According to the invention, the rewinding machine is characterized in that positioned along said feed path is a device to produce, on the web material, at least one longitudinal weakening line or line to facilitate folding. The rewinding machine can comprise, upstream of the winding unit, an embossing unit, in which at least one embossing roller can have protrusions that produce the weakening line or line to facilitate folding. Further advantageous characteristics and embodiments are indicated in the appended claims and in the description hereunder of preferred embodiments of the invention. Brief description of the drawings

The present invention will be better understood by following the description and accompanying drawing, which shows non-limiting practical embodiments of the invention. More specifically, in the drawing:

Figure 1 shows a perspective view of a product in a roll according to the invention in a first embodiment;

Figures 2A-2D show a second embodiment of the product according to the invention and a schematic representation of its use;

Figure 3 shows a schematic side view of a device for producing the product according to the invention;

Figure 4 shows a varied embodiment;

Figure 5 shows a varied embodiment of a product in a roll according to

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the invention;

Figure 6 shows a manner of using the product in Figure 5;

Figures 7 and 8 show varied embodiments equivalent to Figures 1 and 5; Figure 9 shows the flat development of a modified embodiment of a perforator roller for a perforator unit utilizable in a modified embodiment of the invention;

Figure 1OA shows a roll produced according to a different embodiment of the invention; Figure 1OB shows a sheet detached from the roll in Figure 10A and folded along the intermediate diagonal line to facilitate folding;

Figure 11 shows the flat development of a portion of an embossing roller to produce a material of the type shown in Figures 10A; 10B;

Figure 12 shows a diagram of an embossing unit which can use the roller in Figure 11 and be positioned upstream of the winding unit; and

Figure 13 shows a roll of web material according to yet another embodiment of the invention. Detailed description of preferred embodiments of the invention

Figure 1 schematically shows a first embodiment of a paper web product in a roll according to the invention. Figure 1 shows an unwound portion of the wound roll, indicated generically with R. The web material N which forms the roll R has two parallel longitudinal edges and a plurality of equidistant transverse perforation lines 3. These divide the web material N into single sheets F, which can be detached individually to be utilized. In a median position between the two longitudinal edges 1, the web material N has an intermediate longitudinal weakening line, or line to facilitate folding, indicated with 5. This line can be a mechanical ply-bonding line, a score line or a perforation line. Irrespective of its nature, this line can be continuous or discontinuous, for example it can be omitted in the sections at the level of the transverse perforation lines 3. In this way, each sheet delimited between two transverse perforation lines 3 is composed of two adjacent portions more or less identical to each other, separated by the intermediate longitudinal line. The single adjacent portions, rectangular or square in shape, are indicated with 7.

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As can be seen in Figure 1 , four adjacent portions 7, i.e. with a vertex in common, are characterized by variable designs. In this embodiment, the four designs represent objects relating to seaside vacations (beach umbrella, life buoy, scuba mask, glass, slice of watermelon, sailboat). These decorative designs are repeated with constant spacing along the length of the wound web material N forming the roll R. Several different designs can be made on this material, alternating in each of the bands into which the roll is divided by the line 5. In the example shown the designs are positioned so that, for example, the four lower portions which have a common vertex on the line 5 are characterized by designs all different from one another, while the four subsequent portions have two identical decorative designs (scuba masks) in the two portions positioned symmetrically with respect to the common point of the four vertices of the portions.

It will be understood that the designs represented here, and their positioning, are purely non-limiting examples. In fact, the decorative designs can be positioned so that each set of four portions having a common vertex is always characterized by four different designs. Preferably, the four designs contained in the four adjacent portions 7 differ from one another but all relate to the same subject, although this is not binding. For example, they can be composed of designs related to the four seasons, or can represent the colors or symbols of soccer teams, the flags of different countries, and so forth.

However, it would also be possible for the subjects to all be the same as one another along the entire length of the roll, to differ from one another in groups of four adjacent subjects and for the groups to be arranged in a checkerboard motif (in this case the final user can decide whether to take four identical subjects from the roll or, simply by staggering the perforation line by one step, to take two pairs of different subjects), to differ in groups of two subjects adjacent in a radial or transverse direction, or in any other way.

The designs of the single portions 7 can be printed or embossed designs or can be obtained with combinations of printing and embossing. The web material N is advantageously a multi-ply material, and according to an advantageous embodiment the various plies of which it is composed (typically two or more) are joined by embossing and gluing.

The product thus produced can be utilized by inserting the roll R in a

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usual dispenser for rolls of kitchen towel. When the product is used as kitchen towel, the user will tear off the required number of sheets F or portions 7 from the roll. If the intermediate longitudinal line 5 is a perforation line the user can take, time by time, a full sheet F composed of two adjacent portions 7, or a single portion by tearing it from the remaining material along a transverse perforation line 3 and along the intermediate longitudinal perforation line 5. If the roll R has the same axial length as common rolls of kitchen towel (approximately 240 mm) and the perforation lines are spaced approximately 120 mm apart, small square sheets can be torn off to be used, for example, as a coaster or on which to place biscuits, cakes or the like. In this way a considerable saving of paper is obtained compared to the use of conventional rolls, where each time a sheet of paper is torn off a quantity several times the quantity obtainable with a product according to the invention is taken and utilized. The product according to the invention, however, can be utilized advantageously as a napkin folded in four. When the user wishes to use the product in this way, he will take a block of four adjacent portions 7 from the dispenser each time, folding it along the two lines 3 and 5 dividing said portions. The perforation lines 3 and 5 facilitate folding in four along the center line. The napkin folded in four obtained will be characterized by two sides with different designs. Depending on how the group or block of four portions 7 is folded, sides with different designs will be exposed on the outside. This not only makes it possible to utilize the roll R (normally used as kitchen -towel) to obtain napkins folded tidily in four, but also, for example, to decorate a laid table with a distribution of various designs represented on the different sides of the folded napkins.

As in the napkin the designs must be as centered as possible in relation to the side of the folded napkin in view, in order to conceal any misalignments, i.e. lack of centering between the edges of the folded napkin and the main design, geometric motifs composed, for example, of embossing protrusions 11, are produced along the edges 1 , the transverse folding lines 3 and the intermediate longitudinal line 5 to facilitate folding (whether it is a mechanical ply-bonding line, a score line or a perforation line). These mask any defects and inaccuracy in positioning of the main designs or any

_ _ inaccuracy in the orthogonality between the lines 3 and 5, as both in an axial and in a longitudinal direction, the protrusions are not perfectly aligned with respect to those adjacent, to prevent offering the eye of the user a linear reference and thus ensure a certain degree of tolerance in the precision of the transverse 3 and longitudinal 5 perforation lines.

Figure 2 shows a different product obtained with the same concept. Figure 2A shows the roll with an end unwound and Figures 2B, 2C, 2D show the folding sequence of a napkin composed of a section of web material N comprising four adjacent portions 7. The same numbers indicate the same or corresponding parts to those in Figure 1. In Figure 2 the embossing protrusions along the lines 3 and 5 are omitted. The decorative designs of the portions 7 are represented by designs with a seaside theme. In the example illustrated the designs shown can be composed of embossing protrusions which, as in the case in Figure 1 , also serve the purpose of joining together the two or more plies of which the product is composed, in virtue of the fact that a glue, preferably colored, is distributed on these protrusions, to be used as a medium to bond the plies according to techniques known to those skilled in the art.

Nonetheless, as in the case in Figure 2, the designs can be composed of printed designs and bonding of the plies can be obtained by applying glue

(e.g. applied on small embossing points not represented in the drawing and with uniform distribution or a distribution in phase with the printed designs, according to techniques known in the field of ply embossing and laminating).

As when the web material N is utilized as web to produce napkins folded in four the napkin must not be torn along the intermediate transverse line 3, according to a possible embodiment the transverse lines 3 are composed of perforation and tearing lines alternated with score lines with 1 :1 alternation. This can, for example, be obtained by equipping the perforation unit with scoring blades alternated with perforation blades. Figure 4 schematically shows a roll R in which score lines, indicated with 3C, are interposed between transverse perforation lines 3.

Alternatively, the perforation unit can comprise perforation blades of two different types, alternated with each other: a first type of blade produces perforation lines at the level of which the single sheet of web material is torn

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off, while a second type of blade produces more resistant perforation lines, that is, less liable to tear, at the level of which transverse folding is facilitated.

Figure 5 shows a different embodiment of the roll in Figure 1. The same numbers indicate the same or equivalent parts to those in Figure 1. The product represented here corresponds to the one in Figure 1, with the exception that the geometric embossing motifs 11 are not provided along the intermediate longitudinal line 5 for weakening or to facilitate folding.

Moreover, they are only provided along one in every two perforation lines 3. If the transverse lines are composed of perforation lines 3 alternated with score lines 3C as in Figure 4, the geometric motifs 11 will be produced along the perforation lines 3 and not along the score lines 3C.

In this configuration four adjacent portions 7 define a napkin foldable in four along the lines 3 and 5, which is decorated along the four edges by strips or bands of decorative embossed motifs or the like 11 , in the same way normally occurring on conventional napkins. Advantageously, if the embossing motifs 11 are also used to laminate and join the two or more plies of which the finished product is composed, this also serves to prevent separation and flapping of the plies, as the bonding points are very dense along the four edges of the napkin and prevent it from opening; at the same time, the softness of the napkin is not impaired, as there is no excessive stiffening of the center part of the napkin thanks to the presence of a small amount of glue. The napkin thus obtained is consequently more similar to a conventional napkin, of the type packaged in packs of pre-folded napkins.

Figure 6 shows the same product in Figure 5 utilized as normal kitchen towel by detaching a single portion 7, in which the plies are perfectly glued on two sides, while in the rest of the sheet obtained, formed of the single portion 7, the plies are glued only in more widely scattered areas. Instead, in the case in Figure 1 , each portion is surrounded by areas of glue with high density, so that each portion 7, if separated from the adjacent portions, has a perfectly glued border.

Figures 7 and 8 show varied embodiments of the products in Figures 1 and 5 respectively. The same numbers indicate the same or equivalent parts. In these examples of embodiment, the single portions into which the paper web material is divided have designs distributed in such a way that the four

_ portions with a common vertex always have four different designs.

Figure 3 schematically shows a rewinding machine for producing a roll of web material according to the invention. The rewinding machine has a winding unit 21 , composed in this example of a winding cradle formed by three winding rollers 23, 25 and 27. It would also be possible to use other winding systems, such as a central or spindle winding unit.

A perforator unit 29, comprising a beam 31 supporting fixed counter- blades utilizable alternatively, and a perforator roller 33 equipped with a plurality of perforation blades, are positioned upstream of the winding unit. As mentioned, the roller 33 can have perforation blades only, or an alternate arrangement in which a scoring blade is inserted between each pair of perforation blades; said scoring blade cooperates with the counter-blade, to make a score on the web material rather than a perforation. Alternatively, as mentioned, the scoring blade can be replaced by a toothed blade, which produces a more resistant perforation to those produced by the other perforation blades.

A device 35 to produce the intermediate longitudinal line or lines 5 to facilitate folding is positioned upstream of the perforator unit 29. These lines can be perforation, mechanical ply-bonding or also score lines. Depending on the type of machining performed on the web material, the device 35 will be equipped with different tools. In the example illustrated, the device 35 has a counter-pressure roller 37 made of hardened steel or another hard material, cooperating with which are circular tools 39 that can be composed of toothed perforation wheels or mechanical ply-bonding wheels. As is known, rewinding machines process webs of paper material of considerable width, even up to 5 meters to produce logs with a high axial length which are then cut transversely to obtain rolls R. Therefore, the device 35 will in general have a plurality of tools 39 axially aligned with one another to produce on the ply or web of paper an adequate number of intermediate perforation lines, mechanical ply-bonding lines or score lines, which will be centered on the center lines of the single rolls to be obtained by transversely cutting the log L formed in the winding unit.

Figure 9 shows the flat development of a perforation roller of a different conformation. In this case the perforator roller, which can be utilized in place

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of the roller 33, has perforation blades L oriented according to an angle α with respect to the axis A-A of rotation of the roller. Moreover, positioned between adjacent blades L are auxiliary blades LI ₁ which can for example be composed of plastic blades or in any case of elements that produce a deformation such as a score, but not a cut or perforation, on the web material. The auxiliary blades L1 have an inclination of approximately 45° with respect to the blades L and produce on the web material lines to facilitate folding or weakening lines which extend more or less in coincidence with one of the diagonals of each sheet defined, in the finished roll, by the longitudinal edges 1 and the transverse perforation lines.

Figure 10 schematically shows the finished product obtained after winding of the log and longitudinal cutting. The same numbers indicate the same or equivalent parts to those in the example illustrated in Figure 4. The longitudinal weakening line or line to facilitate folding is indicated with 5X. It is longitudinal in the sense that it extends with an angle differing by 90° with respect to the edges 1 of the web material N, that is to say, it has a component parallel to the longitudinal extension of the web material. However, it is not parallel to the edges 1 , but has a diagonal inclination. This line can be produced so that it does not reach the edges 1 , but extends to a lesser degree to avoid difficulties in phasing between perforation and score.

In place of a perforation roller, the line or lines to facilitate folding or weakening lines can be produced with an embossing roller of an embossing unit of the type illustrated schematically in Figure 12, and which can be positioned upstream of the winding unit of the rewinding machine. The numeral 101 indicates the embossing roller, 103 a pressure roller coated in an elastically yielding material, forming a counter-pressure roller with which the embossing roller 101 cooperates. V1 and V2 indicate two plies fed to the embossing unit, 105 indicates a glue dispenser, 107 a second counter- pressure roller and 109 a guide roller of the web material N obtained by joining the plies V1 and V2 by embossing and gluing. These embossing units are known per se and will not be described in greater detail herein.

Figure 12 shows a plan development of a portion of the cylindrical surface of the embossing roller 101. This has embossing protrusions 111 that impress on the ply V1 a permanent deformation composed of corresponding

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protrusions in the material forming the ply. Besides the protrusions 111 that make the decorative embossing, the roller 101 also has linear protrusions 113, which produce the lines to facilitate folding or the weakening lines. In this example, these are protrusions inclined by approximately 45° with respect to the axis A-A of the embossing roller, as they produce diagonal lines 5X (Figures 10, 10A). It would also be possible to produce on the embossing roller 101 annular protrusions to produce lines to facilitate folding or weakening line that are substantially parallel to the edges 1 of the final web material N wound on the roll R. Figure 13 shows a varied embodiment of the product in Figures 10A,

1OB. In this case, besides the embossed designs D produced in the triangular portions 7, into which the line 5X divides the single sheet F, embossings G are also provided along the edges 1 and along the perforation lines 3 delimiting the sheet F. These embossings G can be deeper, that is to say, they can have heights greater than those defining the designs D. In this way the glue applied by the glue dispenser 105 of the embossing unit is only applied to the embossings G, leaving the central area of the single sheet F softer. If the line 5X is produced by a linear protrusion of the embossing roller, as in the case of Figure 11 , it can have a height equivalent to that of the embossings G, so that the glue is also applied, although in very small quantities, in the central area of each sheet F, which (in combination with the glue on the perimeter embossings G of each sheet) guarantees sufficiently stable bonding by gluing of the two or more plies (i.e. V1 , V2) forming the web material N. The absence of glue on the designs D inside the sheet F makes it possible to obtain the further advantage of improving differentiation between the two sides of the web material, in the case in which it is provided with different motifs or embossed designs on said opposite sides.

In the case in which the web material N is equipped with inclined longitudinal lines to facilitate folding or weakening lines, these can also be positioned alternately, i.e. be inclined by +45° in one sheet and by -45° in the subsequent sheet. Moreover, as mentioned, two lines to facilitate folding or weakening lines can be provided on the same sheet F along the two diagonals of said sheet F.

It is understood that the drawing only shows non-limiting practical

embodiments of the invention provided by way of example, and that said invention can vary in forms and arrangements without departing from the concept on which it is based. Any reference numbers in the appended claims are provided purely to facilitate reading in the light of the description and of the drawings and do not in any way limit the scope of protection.