TECHNICAL FIELD The present invention relates to a continuous web of a web-shaped material separable into individual sheets by breaking the web in pre-defined separation areas comprising a plurality of slits and a plurality of connection areas in between the slits. The invention further relates to a roll of such a web and a set comprising a dispensing device and such a roll.

BACKGROUND OF THE INVENTION

It is well known to divide a continuous web into separable individual sheets by means of perforation. The perforation could consist of a number of slits separated by connection areas. Sometimes the perforation instead has a large number of point-like holes adjacent to each other or punched holes instead of slits. Traditionally, a straight perforation in the transverse direction of the web has been used.

The individual sheets may be tickets in a ticket dispensing machines, e.g. for queue tickets, coupons or receipts, which are adapted to be separated manually from each other. The individual sheets may also be sheets of tissue paper, e.g. toilet paper, household paper or wiping paper.

Depending on the application, it is sometimes desirable to be able to print information on the individual sheets such as queue number, date and time, name of an event, information, advertising or the goods purchased as well as the cost. It is thus in this case preferred that the individual sheets have an area suitable for printing. An appropriate shape of the print area is essentially square or rectangular. The sheet may be printed on both sides, but commonly only one side is used. The print may also be for decorative purposes.

On one hand the web should be strong enough, so that it does not break during manufacturing or in the dispensing device. On the other hand, it should be easy to separate an individual sheet, so the perforated web cannot be too strong. With the traditional straight perforation, it might be difficult to find a good trade-off since the two desires are contradictory. It is also desired that the web actually breaks in the perforation, giving a complete sheet, so that a possible print or feed out from a ticket dispensing machine is not negatively influenced by a tear.

SE529904 discloses a continuous web divided by a plurality of separation areas separating sheets. The separation areas consist of a number of separate slits, which are arranged in such a way that the connecting areas in between the slits are substantially subjected to a shear stress when a force is applied in essentially the longitudinal direction.

During manufacturing of the webs, it is common to use a knife or similar sharp edge device to provide the web with the slits of the separation areas. If a slit is a straight transverse line, this means that the knife will hit the material along a line. The pressure is thus distributed over the whole line, leading to that the specific pressure in each point along the line is not so high, as compared to if the knife would only hit point-wise.

Some persons wanting to detach a sheet grip the sheet at or close to one of the corners, while others grip the sheet close to the middle. It is therefore desirable to have a web which is easy to detach into sheets no matter where the sheet is gripped.

SUMMARY OF THE INVENTION

The object of the present invention is to overcome or ameliorate at least one of the disadvantages of the prior art, or to provide a useful alternative.

Preferably, a continuous web of a web-shaped material separable into individual sheets is provided, which works well during manufacturing and in the dispensing machine, at the same time as it is easy to detach an individual sheet. It is desirable that the sheets are easy to detach no matter where the person grips the sheet.

Advantageously, a continuous web of a web-shaped material divided into individual sheets is provided which is efficiently provided with slits in the separation areas during manufacturing.

It is further desirable to have a web providing a suitable printing area on the individual sheets. The object above may be achieved by the invention according to claim 1.

In a first aspect of the present invention there is provided a continuous web of a web- shaped material. The web has a first and a second longitudinal edge and a central axis extending in the longitudinal direction in between the first and second longitudinal edges. The continuous web is separable into individual sheets by pulling essentially in a longitudinal downstream direction of the continuous web and breaking the web in predefined separation areas extending from the first longitudinal edge to the second longitudinal edge. Each separation area comprises a plurality of adjacent elongate slits. For each longitudinal edge

- the first slit being closest to the longitudinal edge extends from an initial position adjacent the edge, in a direction towards the central axis and upstream the web to a final position, - the slit adjacent to the first slit extends from an initial position being downstream of the final position of the first slit and at least towards the central axis.

The adjacent slit may be inclined or transverse.

The continuous web according to the present invention works well during manufacturing and in the dispensing machine, at the same time as it is easy to detach an individual sheet.

The suggested arrangement of the separation area is easy to produce. If using a system with a roll provided with knives or sharp edges to make the slits, a knife/edge will hit the web material point-wise due to the inclined slits, so that the cutting force is used efficiently.

On each sheet there is provided an area which is suitable for printing e.g. information or advertising. Since the web according to the invention is adapted to break nicely at he separation areas giving complete sheets, this information will be easily understood without that the reader have to guess, which would have been the case if for example a corner of the sheet was missing. The continuous web may further have on or more subsequent slits, wherein for each subsequent slit located between each longitudinal edge of the continuous web and the central axis, the slit extends from an initial position being located downstream of the final position of the previous slit, in a direction at least towards the central axis. Especially the direction may be towards the central axis and upstream. The subsequent slits may thus be transverse and/or inclined.

By using subsequent slits, the number of slits can easily be adapted to the width of the web.

The separation area may be arranged so that there is at least one slit having an initial position being located downstream of and closer to the central axis than the final position of previous slit. This arrangement gives a connection area having both transverse and longitudinal extension. Such a connection area would be stronger than a connection area having only longitudinal direction, i.e. a slit having an initial position being located directly downstream of the final position of previous slit. By varying the transverse extension of the connection area, i.e. how much closer the next slit is to the central axis, the strength of the separation area can be adjusted. It is for example possible to make the separation areas locally weaker, to for example provide a web which is easier to separate close to the edges than in the centre.

The continuous web may have a separation area, wherein the initial position of the first slit at the first longitudinal edge is at the same longitudinal position as the initial position of the first slit at the second longitudinal edge. It then does not matter if the person wanting to detach a sheet starts tearing from the left-hand edge or right-hand edge.

The slits may be arranged symmetrically around the central axis. This gives a well- balanced separation area which is easy to tear.

The separation area may further comprise an edge cut being essentially perpendicular to the edge. The edge cut facilitates the beginning of the tear. It also helps to detach complete sheets. The width e of the edge cut typically fulfils 0 < e < 10 mm, preferably 0 < e ≤ 5 mm and most preferably 0 < e ≤ 3 mm. The separation area may have a generally curved form. The shape of the curve could be chosen to facilitate tearing. If cutting the slits with knives on a roll, the curvature will help distributing the applied pressure, so that the web material is hit point-wise making it possible to have a high specific pressure.

In one embodiment, essentially the whole separation area is located on one side relative to a straight line between the first and second edge location, wherein the first edge location is the location where the separation area meets the first edge of the continuous web, and the second edge location is the location where the separation area meets the second edge of the continuous web. In a preferred embodiment, the generally curved form is arc-shaped, which gives a separation area which is easy to tear.

Further, at least one of the slits may be curved. The slit can thus be made in any desired way in order to get the desired separation area.

The angle between a slit and the longitudinal direction could be made greater for a subsequent slit than for the first slit being closest to the longitudinal edge.

In a second aspect of the invention, there is provided a roll comprising a rolled up continuous web with separable sheets as described above.

In a third aspect, there is provided a set comprising a dispensing device and a roll according to the second aspect. The dispensing device has a dispensing opening comprising a lip. Often there is an upper and a lower lip. The generally curved form of the separation areas separating the sheets of the web in the roll may be selected so that it mimics the curvature of at least one of the lips of the dispensing opening. This facilitates detaching the web into sheets, at the same time as it gives a visually pleasing impression.

BRIEF DESCRIPTION OF THE DRAWINGS The present invention will hereinafter be explained in greater detail by means of non- limiting examples and with reference to the appended drawings in which:

Fig 1 is a part of a continuous web according to a first embodiment of the invention, Fig 2 is a part of a continuous web according to a second embodiment of the invention,

Fig 3 is a part of a continuous web according to a third embodiment of the invention,

Fig 4 is a part of a continuous web according to a fourth embodiment of the invention.

Fig 5 is a part of a continuous web according to a fifth embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS The invention will, in the following, be exemplified by embodiments. It is to be understood, however, that the embodiments are included in order to explain principles of the invention and not to limit the scope of the invention, defined by the appended claims.

Figure 1 illustrates a part of a continuous web 2 of a web-shaped material according to a first embodiment of the invention. The web 2 has a central axis A and a first 8 and second

10 longitudinal edge. The web 2 is divided into individual sheets 4 by separation areas 6.

In the separation area 6, the continuous web is weaker than for the rest of the web, so that the web more easily breaks off in the separation area. Each separation area 6 comprises a plurality of slits 12, 14, 16 and a plurality of connection areas 18, 20. The connection areas are located between the ends of adjacent slits and connect the sheets when they are in the web. When a sheet 4 is detached from the web 2, the sheet is separated by tearing in the connection areas 18, 20.

The first slit 12, 16 being closest to respective longitudinal edge 8, 10 extends from an initial position adjacent the edge, in a direction towards the central axis (A) and upstream the web to a final position. The slit 14 adjacent to the first slit 12, 16 extends from an initial position being downstream of the final position of the first slit 12, 16 and at least towards the central axis (A). The connection areas 18, 20 therefore have a longitudinal extension. By using an arrangement comprising connection areas with longitudinal extension, it is secured that the connection areas at least partly are subjected to shear forces when tearing off an individual sheet.

The directions upstream and downstream relates to the main pulling direction when detaching the individual sheets. A thought person wanting to detach a sheet is supposed to grip the last sheet at the free end of the web and detach it from the web. With the illustrated web of Figure 1 , the sheets 4 are intended to be torn off starting from the bottom of Figure 1. The downstream direction therefore is downwards in Figure 1.

A common problem when using webs of continuous material with detachable sheets, is 5 that persons wanting to detach a sheet may grip the sheet to be detached at varying locations. Some persons grip close to central axis (A), while others may grip close to the corners of the free end. With conventional designs of the separation area, there is a risk that the sheet will not detach properly when gripping close to the corners. Instead the material of the web could break outside the separation area leading to an incomplete 10 sheet.

The separation area 6 of Figure 1 has however been specially designed so that it also may work for persons gripping at the corners. If somebody is gripping and pulling from the lower left-hand corner, the right-hand connection area 20 would be subjected to

15 essentially shear forces while the left-hand connection area 18 is subjected to a mixture of shear and length forces. Therefore the right-hand connection area 20 would break first. Once it is broken, all force is taken by the left-hand connection area 18 which then breaks subsequently. Correspondingly, if somebody is gripping from the lower right-hand corner, the left-hand connection area 18 would break first. If somebody is gripping close to the

20 central axis, both connection areas 18, 20 are subjected to mainly shear force and would break more or less at the same time.

The separation area 6 signals to the person wanting to detach a sheet that the web is most easily broken in that area. In order to enhance the signalling, an extra print in a 25 differing colour could be made on the same side as the information/ advertising print or on the back side. Such a signal print may be printed over the whole width of the separation area or mark the separation area at the edges.

The number of slits may be 3, 4, 5, 6 or more. Both an even number and an odd number 30 of slits would work. The length of the slits may vary, but they are typically 3-30 mm, preferably 5-15 mm. All slits may have the same length, or the length may vary over the width of the web. By adjusting the number of slits and their length, adaptation could be done for the width of the web and the used web material. Purely as an example, typical webs for queue tickets are between 20 and 120 mm wide, preferably between 30 and 35 100 mm and most preferably 40 and 80 mm. The longitudinal extension of a connection area is in the case of queue tickets typically between 0.1 and 5 mm, preferably 0.3 and 3 mm.

It is preferred that each slit comprises one slit section as in Fig 1 or a hole. However it is also possible that a slit comprises two, three or more slit sections/holes separated from each other by small portions of the web material. The slit sections belonging to the same slit are in that case aligned with each other. The small web portions between the individual slit sections of the same slit have essentially no or only a tiny longitudinal extension and can thus be differed from the above-mentioned connection areas. These small web portions also have to be torn off when detaching the sheet. It would also be possible to let each slit comprise a line of holes very close to each other.

The longitudinal extension f of the separation area depends on the width of the web but is typically between 1 and 30% of the web width, preferably between 2 and 20% and most preferably between 3 and 10%. For an exemplary 60 mm wide web, this is between 0.6 and 18 mm, preferably between 1.2 and 12 mm and most preferably between 3.6 and 6 mm. It differs from 0, since 0 would be a straight transverse line. The longitudinal extension f is taken as the longitudinal difference between the lowermost point of the lowest slit and the uppermost point of the highest slit. Low and high are seen in relation to the downstream direction.

As mentioned above, the web of Figure 1 is intended to be detached starting at its lower end. It would however also work to detach sheets from the upper side of Fig 1. A possible person gripping at the corner would in that case first break the connection area being closest to the same longitudinal edge.

In Figure 2, the separation area 6 comprises a first slit at each edge 12, 16 and a plurality of subsequent slits 22, 24, 26, 28, 30, 32. For each side of the central axis A, a subsequent slit extends from an initial being located downstream of the final position of the previous slit, in a direction towards the central axis A and upstream. The previous slit is the adjacent slit being closer to the closest edge. For example, for slit 22 the first slit 12 is the previous slit, while for slit 24, the slit 22 is the previous slit etc. It would also be possible to let one or more of the subsequent slits to be transverse. In order to improve the tear-off characteristics, the web 2 may be provided with an edge cut 34, 36 as illustrated in the third embodiment seen in Figure 3. The edge cut 34, 36 is essentially perpendicular to the edge and it is intended to work as a starting point for the tearing when detaching a sheet. If there are edge cuts at both longitudinal edges, one of the edge cut may act as a starting point for the tear and the other as an end point, giving a distinct tear helping to provide complete sheets. A typical edge cut has a width e, which fulfils 0 < e < 10 mm, preferably 0 < e < 5 mm and most preferably 0 < e < 3 mm.

Figure 4 illustrates a fourth embodiment having a separation area 6 with a generally curved form. In this case the generally curved form is unimodal i.e. having one maximum. If a straight line 38 is drawn between the first edge location 40 and the second edge location 42, the whole separation area is located on one side of this line. An edge location is the location where the separation area 6 meets the longitudinal edges 8, 10 of the web 2. The invention would also work for curves having more than one extreme point, e.g. one maximum and one minimum; however the curves tend to be better balanced with an uneven number of extreme points, e.g. one max or max-min-max. For the generally curved separation area 6 of Figure 4, the longitudinal extension f is taken as the longitudinal difference between the lowermost point of the lowest slit and the uppermost point of the highest slit. Low and high are seen in relation to the downstream direction. The sheets are intended to be pulled starting from the bottom of Figure 4.

The illustrated curve of Figure 4 is arc-shaped, which is a suitable form. In geometry, an arc is a closed segment of a differentiable curve in the two-dimensional plane. For the present invention suitable arcs are circular arcs or elliptical arcs, being a segment of the circumference of a circle or an ellipse, respectively.

The general curved shape of the separation area of Figure 4 is further longitudinally symmetric, i.e. it has a symmetry axis lying in the longitudinal direction. In this case, the symmetry axis is located at the central axis A, which often is preferred since most persons grab the sheet in the centre when detaching it from the web, and if grabbing close to the corner, it is as easy to tear from the left-hand side as from the right-hand side.

In Figure 4 each slit has a different orientation from its adjacent slit. Orientation is defined as the angle α, β between the slit and the longitudinal direction. It may, however, also be possible that two or more slits have the same orientation. A few slits may be in the transverse direction, like the central slit of Fig 4, but normally the majority of the slits have an orientation α, β being between 45° and 90°. In Figure 4 it is illustrated that the angle between a slit and the longitudinal direction is greater for a subsequent slit (22, 24, 26, 27, 28, 30, 32) having the angle β than for the first slit (12, 16) being closest to the longi- tudinal edge (8, 10) having the angle α.

The individual slits may be curved as in Figure 5. For a curved slit 44, the orientation is defined as the orientation of a straight line between the ends of that slit. The slits are more oriented close to the edges. The web of Figure 5 also has edge cuts like the ones of Figure 3.

The transverse and longitudinal displacements between adjacent slits may vary over the width of the web. It is for example possible to make the web weaker at the edges by having less transverse displacement at the edge than in the centre. It would also be possible to let the web be weaker in the centre.

Suitable material for the continuous web are thin web-shaped materials like paper, tissue paper, cardboard, non-woven, foil, plastic or fabric as well as laminates combining one or more of these materials. The dimensions of the slits and the locations of the slits may preferably be adapted to the web material used.

Webs according to the invention usually have a preferred direction for detaching sheets starting at on end of the web, which define the downstream direction. However, it would also work to detach the sheets starting from the other end of the web, but this is less preferred.

Since it is usually not known on before-hand where the person wanting to detach a sheet places his grip, it is usually preferred to make the separation area symmetric around the central axis.

For the application as queue tickets, paper is the most common material. Paper normally has an inherent fiber orientation distribution caused by the manufacturing method. Normally more fibres are oriented in the machine direction MD of the paper machine than in the cross-machine direction CD. More fibres also lead to higher strength in MD than CD. The web is therefore strongest in the longitudinal direction, which coincides with the machine direction MD of the paper machine. When the web is handled during production and during feeding in the dispensing device, the applied forces are mainly in the longitudinal direction, which is in the direction in which the web is strongest. When detaching sheets from a web according to the invention, the tear force is more or less a shear force, which is more difficult for the web to withstand. Depending on the strength of the individual fibres as compared to the strength of the fibre-to-fibre bindings, the web in the connection areas will either break in the fibre-to-fibre bindings or by breaking off individual fibres.

The separation areas according to the invention would also work for applications within the tissue industry, for example toilet paper, household towel, hand wiping or object wiping. These products are often sold on rolls, where the user tears off as much tissue as he needs. Tissue paper is often perforated to make the tear-off easier or to allow consumption control. Since tissue rolls normally are wider than queue ticket rolls, the number of slits and the lengths of the slits should be adapted both to the appropriate web width and to the paper characteristics.

In most applications the web is rolled up in the form a roll, but it is also possible to for example make a stack by folding the web back and forth. The stack may comprise two or more webs which are folded into each other.

In use, the web is commonly supplied by a dispensing device. The roll is suspended in or on the device and the web is fed so that it is easy for the user to detach a sheet. Examples of such dispensers are queue ticket machines and dispensers for tissue paper. As an extra feature the curvature of the separation areas of the web can be formed in such a way that it mimics the curvature of one or both lips of the dispensing machine.

The invention has been described above by way of example only and the skilled person will appreciate that many modifications of the above-described embodiments are conceivable within the scope of the appended claims.

Examples of such modifications are varying web materials, geometric form of the separation area, number and lengths of slits, distance in between slits, using edge cuts or not, use of curved and/or or straight slits etc.