Dispenser

Abstract

A dispenser for dispensing at least one perforated web from a storage of web material, the dispenser including: a housing arranged to hold a storage of perforated web material, wherein a web path extends along a feeding direction in an interior of the housing from a storage position to a dispensing opening of the dispenser, and a separation arrangement being arranged along said web path, for separating the at least one perforated web along the perforations thereof, said separation arrangement including a first unit and a second unit, the second unit being arranged downstream said first unit, as seen in the feeding direction of the web path. The first unit is arranged to provide a tensioning force on said web, and the second unit being arranged to stretch the web material along the length of the web and along the width of the web.

Claims

1. A dispenser for dispensing at least one web material, said web material comprising perforation lines dividing said web material into individual products, from a storage of web material, the dispenser comprising: a housing comprising the storage of the web material, wherein said web material extends along a web path in a feeding direction in an interior of said housing from a storage position to a dispensing opening of the dispenser, and a separation arrangement being arranged along said web path, for separating said at least one web material along said perforation lines, said separation arrangement comprising a first unit and a second unit, said second unit being arranged downstream said first unit, as seen in said feeding direction of said web path, wherein said separation arrangement is adapted to provide a first pull force required to pull said web material downstream said first unit, and a second pull force required to pull said web material downstream said second unit, said first pull force being 10 to 50% of said second pull force.

2. A dispenser according to claim 1, wherein said first pull force is greater than 0.5 N.

3. A dispenser according to claim 1, wherein said second pull force is less than 8 N.

4. A dispenser according to claim 1, wherein said second pull force is less than a perforation strength of said perforation lines of said web material.

5. A dispenser according to claim 1, wherein said storage of web material is in the form of a stack.

6. A dispenser according to claim 1, wherein said web material comprises a first web being divided into sheet products defined between subsequent perforation lines extending over a width of said first web.

7. A dispenser according to claim 6, wherein said web material comprises at least a second web being divided into sheet products defined between subsequent perforation lines extending over a width of said second web, and wherein said first and second webs are interfolded so that said perforation lines of said first web are offset from said perforation lines of said second web in a length direction of said first web.

8. A dispenser according to claim 1, wherein said web material comprises a plurality of individual web sections, said web sections being interconnected by connecting members.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The various aspects of the invention, including its particular features and advantages, will be readily understood from the following detailed description and the accompanying drawings, in which:

(2) FIG. 1 illustrates a dispenser according to embodiments,

(3) FIG. 2 illustrates a dispenser for dispensing web material according to embodiments,

(4) FIG. 3 illustrates the dispenser of FIG. 2 with a door in an open position,

(5) FIGS. 4A-4B illustrate details of the dispenser according to embodiments, and

(6) FIG. 5 illustrates schematically a cross section through a stack of web material according to embodiments.

DETAILED DESCRIPTION

(7) The present invention will now be described more fully with reference to the accompanying drawings, in which example embodiments are shown. However, this invention should not be construed as limited to the embodiments set forth herein. Disclosed features of example embodiments may be combined as readily understood by one of ordinary skill in the art to which this invention belongs. Like numbers refer to like elements throughout. Well-known functions or constructions will not necessarily be described in detail for brevity and/or clarity.

(8) FIG. 1 illustrates a dispenser 2 according to embodiments. The dispenser 2 comprises a housing 4, which housing 4 comprises a door 6. The door 6 is illustrated in an open position to reveal an interior of the housing 4. The dispenser 2 is arranged for dispensing web from a stack 8 of web material. Accordingly, the housing 4 is arranged to hold the stack 8 of web material. The stack 8 comprises continuous web material which is Z-folded in an accordion-like manner. The web material comprises a first web, which may be divided into individual products defined between subsequent perforation lines, extending over a width of the first web. The stack 8 may be a stack as illustrated in FIG. 5.

(9) In an interior of the housing 4, a web path extends from a stack position 10 to a dispensing opening 12 of the dispenser 2. The stack position 10 in the housing 4 is a portion of the housing 4 adapted to hold the stack 8 of web material. Accordingly, the stack position 10 extends over the portion adapted to hold the stack 8, from the top of the stack 8 when the dispenser 2 has been newly replenished with web material, as illustrated in FIG. 1, to a stack supporting lower surface inside the housing 4 when nearly all the web material has been dispensed from the stack 8. The dispensing opening 12 is arranged in the door 6 of the housing 4.

(10) In the illustrated embodiment, the web path extends in a first direction 14 in a first portion 16 of the housing 4 and in a second direction 18 in a second portion 20 of the housing 4. The first direction 14 is directed substantially opposite to the second direction 18. The web path has been illustrated with broad arrows, and a tail 21 of the web material extending along the web path has been illustrated with broken lines, in FIG. 1.

(11) The housing 4 comprises an access opening 22 in a first side portion 24 of the housing 4. The access opening 22 provides access to the interior of the housing 4. The door 6 is arranged to open and close the access opening 22. The web path is accessible along a third direction 26, in both the first and second portions 16, 20 of the housing 4, via the access opening 22. Thus, an attendant may open the door 6 to access the access opening 22 and the interior of the housing 4, e.g. for replenishing the dispenser 2 with a stack 8 of web material and/or for threading the tail 21 of web material from the stack position 10 along the web path to the dispensing opening 12. The third direction 26 is substantially perpendicular to the first and second directions 14, 18.

(12) Seen in a direction from the access opening 22, i.e. in the third direction 26, the first portion 16 of the housing 4 is arranged after the second portion 20 of the housing 4. The first portion 16 of the housing 4 is arranged adjacent to a first wall 27 of the housing 4. The first wall 27 is arranged opposite to the access opening 22. The second portion 20 of the housing 4 is arranged adjacent to the access opening 22.

(13) Although the arrangement of the web path as described in the above provides advantages, it is not necessary to obtain the advantages of the aspects of the invention. Instead, other arrangements of web paths may be conceivable, for example where the web path run in only one direction, or in two directions not being opposite to one another.

(14) An arrangement for dispensing the web material is arranged along the web path. The arrangement may be adapted such that passages thereof, through which the web passes, may be automatically adjusted in accordance with intermittent thickness variations in the web material. The arrangement may further be arranged such that a correct tension, web stretch and pull force is maintained irrespective of the presence of intermittent variations in web material thickness.

(15) In the dispenser 2 illustrated in FIG. 1, the arrangement comprises a first support element 28 for the web material and a second support element 30 for the web material. Part of the web path extends between the first and second support elements 28, 30 and over the first support element 28. The first direction 14 extends from the stack position 10 to the first support element 28, and the second direction 18 extends from the first support element 28 to the second support element 30. The web path is accessible at a level 32 defined between the first support element 28 and the second support element 30, in both the first and second portions 16, 20 of the housing 4, via the access opening 22.

(16) The first and second support elements 28, 30 are comprised in a separation arrangement 60 for separating an individual product of web material from the tail 21 of the web material. The separation arrangement 60 comprises a first unit 61 and a second unit 62, which is arranged downstream of the first unit 61. The first and second units 61, 62 are adapted to cooperate in order to provide the desired dispensing of individual web products through the dispensing opening 12.

(17) The first unit 61 comprises the first support element 28, which in turn comprises a first roller 38. The first roller 38 may be resiliently arranged, by being pivotally suspended in the housing 4. It may also be biased, e.g. by spring biasing, thereby biasing the first roller 38 toward a default position. Thereby, the first roller 38 may be deflected during forces provided between the first roller 38 and the web material as the web material moves along the web path. The first roller 38 may be directly or indirectly suspended in the housing 4. The first unit 61 is configured to provide a tensioning force on the web material. The tensioning force prevents the web material 8 from moving backwards towards the stack position 10, or in a lateral direction during, the use of the dispenser or in case of web-breakage. Moreover, the tensioning force provides a pretension to the web material 8 before reaching the second unit 62. In the embodiment illustrated in FIG. 1, the tensioning force may be realized by friction between the surface of the first roller 38 and the web material, and by the inertia of rotation of the first roller 38. The first roller 38 may be provided with a coarse or rough surface, such as to provide a friction against the web material high enough to provide a desired tensioning force. Such a coarse surface may be a provided by mechanically or chemically modifying the surface of the roller or by applying a coating thereto. The first roller 38 may also be arranged such as to have a resistance against rotation thereof, especially in a direction opposite the intended direction of movement of the web material 8 along the web path.

(18) The second unit 62 of the separation unit 60 comprises the second support element 30. The second support element 30 comprises a second roller 34 and a third roller 36. A passage for the web material is formed between the second and third rollers 34, 36. The second and third rollers 34, 36 are arranged relative each other with a gap there between, such as not to contact each other. Thereby, the web material will substantially not be nipped or pressed during passage through the gap. However, the second and third rollers 34, 36 are arranged to contact the web material as it passes through the passage, such as to stretch the web material along its length and width.

(19) The second and third rollers 34, 36 may be resiliently arranged, by being pivotably suspended in the housing 4. They may be directly, or indirectly, suspended in the housing 4. By the resilient arrangement of the second and third roller 34, 36 the passage for the web material is automatically adaptable to webs of different thicknesses, as well as to intermittent variations in the thickness of the web. Thereby the web material is stretched upon passage through the passage, also at the regions comprising the intermittent thickness variations or adjacent to regions comprising the intermittent thickness variations.

(20) The second and third rollers 34, 36 may be biased, e.g. by use of biasing elements, such as springs (not illustrated). Thereby, the second and third rollers 34, 36 may be biased toward each other by springs, such as to form a default size of the gap forming the passage. By the spring biasing, the gap between the rollers changes automatically as the thickness of the web material passing through the gap varies.

(21) FIG. 2 illustrates a dispenser 2 for dispensing web material according to embodiments. The dispenser 2 comprises a housing 4, and the housing 4 comprises a door 6. In the door 6, a dispensing opening 12 is provided for dispensing the web material. The door 6 is arranged for opening and closing an access opening to an interior of the dispenser 2. The door 6 may be locked in a closed position by means of a locking arrangement 40.

(22) FIG. 3 illustrates the dispenser 2 of FIG. 2 with the door 6 in an open position. Again, the dispenser 2 is arranged for dispensing web material from a stack of continuous web material which may be Z-folded in an accordion-like manner, for example as illustrated in FIG. 5 and as described in detail below. The stack has been omitted in FIG. 3 for clarity reasons. However, from a stack position 10 a web path extends to the dispensing opening 12 of the dispenser 2. The stack position 10 is arranged in a lower portion of the housing 4.

(23) The housing 4 comprises an access opening 22 in a first side portion 24 of the housing 4. The access opening 22 provides access to the interior of the housing 4. The web path is accessible along a third direction 26, in both the first and second portions 16, 20 of the housing 4, via the access opening 22. The web path extends in a first direction 14 in a first portion 16 of the housing 4 and in a second direction 18 in a second portion 20 of the housing 4. The first direction 14 is substantially opposite to the second direction 18. The first direction 14 extends from the stack position 10 to a first support element 28, and the second direction 18 extends from the first support element 28 to a second support element 30.

(24) Although the arrangement of the web path as described in the above provides advantages, it is not necessary to obtain the advantages of the aspects of the invention. Instead, other arrangements of web paths may be conceivable, for example where the web path run in only one direction, or in two directions not being opposite to one another.

(25) In the dispenser illustrated in FIG. 3, the arrangement comprises a separation arrangement 60, which is arranged along the web path. The separation arrangement 60 comprises a first unit 61 and a second unit 62, each of which will be described in more detail below. The second unit 62 is arranged downstream of the first unit 61, seen in the direction of the web path indicated by the arrows 14, 18. Due to the separation arrangement 60, the web material is separated along its perforation lines when the user pulls the web tail protruding from the opening 12. As described above, the first and second units 61, 62 cooperate to feed the web material and separate individual products along the perforations. The first unit 61 will provide a tensioning force on the web material, and the second unit 62 will stretch the web material substantially simultaneously along the length of the web material and along the width of the web material as the web material passes through the separation unit 60, such that the web material may be properly separated by the consumer. The tensioning force may be at least 2 N/m, and may be adjustable, as described below. By configuring the first unit 61 such as to provide an adjustable tensioning force, the pull force required to separate the web material along the perforation lines may also be adjusted. The dispenser may thereby be used together with different types of web material.

(26) The first unit 61 and the second unit 62, according to the embodiment illustrated in FIG. 3, will be described in detail.

(27) The first unit 61 comprises the first support element 28 and a contact element 42, which is arranged to contact the web material in order to provide the tensioning force. The first support element 28 comprises a first roller 38 pivotably suspended inside the housing 4, similar to the first roller 38 described with reference to FIG. 1. The contact element 42 is pivotably arranged inside the housing 4 and arranged to pivot towards the first support element 28 about a pivot axis 44. The contact element 42 may be arranged such that it can be displaced such that no part of it bears against the web supporting surface of the first roller 38 during feeding of the web material 8 in the dispenser 2. Thereby, it may be ensured that an attendant will thread a tail of web material from the stack position 10 over the first support element 28 and under the contact element 42, i.e. through the nip formed there between. After the web material 8 has been fed into the dispenser 2, along the web path, the contact element 42 may be returned to its default position, to provide the tensioning force.

(28) The contact element 42 abuts against the first support element 28, also when no web material extends along the web path. The contact element 42 extends substantially from a first wall 27 of the dispenser 2 to the first support element 28. The first wall 27 is arranged opposite to the access opening 22. The first axis 44 extends along the first wall 27. A nip formed by the first support element 28 and the contact element 42 may hold a tail of the web material and prevent the tail of the web material from sliding backwards towards the stack position 10, due to the tensioning force exerted on the web material by interaction of the first roller 38 and the contact element 42. The contact element 42 may be arranged to pivot towards the first support element 28 from above. Thereby the contact element 42 comes into contact with the web material due to gravity, and the tensioning force exerted by the contact element 42 is primarily provided by the weight of the contact element. The contact element 42 may be adapted such that one or more masses may be removably mounted thereto.

(29) FIGS. 4A-4B illustrate a detail of the first unit 61. FIG. 4B shows a cross section taken along the line A-A of FIG. 4A. FIG. 4B illustrates a first and a second position 64, 66 where masses may be mounted. By choosing the weight of the masses the magnitude of the tensioning force provided by the first unit 61 may be selectively adjusted.

(30) Alternatively, or additionally the contact element 42 may be spring biased against the first roller 38. Thereby, the first unit 61 is resiliently arranged, such that it is automatically adaptable to intermittent variations in the thickness of the web material. By the pivoting, eventually spring biased arrangement of the contact element 42 and the first roller 38 the nip formed there between is automatically adjusted to intermittent variations of the thickness of the web material.

(31) Further, either one or both of the first roller 38 and the contact element 42 may be provided with a coarse surface, which will also contribute to the tensioning force due to friction formed between the coarse surface and the web material. Such a coarse surface may be a provided by mechanically or chemically modifying the surface, i.e. the underside of the contact element 42, or by applying a coating thereto.

(32) By adjusting the tensioning force provided by the contact element 42, the web material may be held with sufficient tension in relation to the second unit 62, such that the second unit 62 may properly stretch the web material and enable dispensing a suitable length of web material 8.

(33) Due to the tensioning force, the web material 8 will be pre-tensioned before reaching the second unit 62. The contact element 42 may also ensure that the interfolded webs will not become displaced with respect to one another as they pass through the dispenser 2.

(34) The tensioning force will provide a braking force on the web material 8 and thereby provide resistance when a user pulls the web material 8 out of the dispensing opening 12. The first unit 61 thereby contributes to the pull force required to be applied by a user in order to pull a portion of the web material out of the dispensing opening.

(35) The second unit 62 comprises the second support element 30. The second support element 30 comprises a separation unit 46 adapted for separating an individual product from the web material coming from a stack of web material 8 inside the dispenser 2. The separation unit 46 is adapted for separating an individual product from a web material comprising perforation lines dividing the web material in to the individual products. The separation unit 46 comprises a second roller 34 having a second rotation axis and a third roller 36 having a third rotation axis. The second and third rotation axes extend in parallel with each other. A passage for the web material is formed between the second and third rollers 34, 36. Similar to the second unit 62 described with reference to FIG. 1, the second and third roller 34, 36 are arranged such that they are not in contact with each other. The passage has a minimum open gap.

(36) The second and third rollers 34, 36 are arranged such that the distance between their respective rotational axes is adjustable. Hence, the size of the minimum open gap of the passage is adjustable.

(37) Similar to the first roller 38 described above, one or both of the second and third roller 34, 36 are pivotally arranged, and are preferably biased in directions toward one another, for example by spring biasing. The second unit 62 is thereby resilient, such that the passage for the web material may automatically adapt to intermittent thickness variations in the web material. Especially, the size of the open gap will be automatically adjusted to intermittent thickness variations in the web material passing through the passage.

(38) The second and third rollers 34, 36 are provided with protrusion elements 48 spaced along the first and second rotation axes. In the illustration of FIG. 3, each of the second and third roller 34, 36 is provided with a plurality of protrusion elements 48. However, it would also be possible that the second and third rollers be provided with corresponding shapes such as to form other shapes, such as to thereby stretch the web material along its width.

(39) The protrusion elements 48 may be integral with the rollers 34, 36, or may be separate elements attached to the rollers. The protrusion elements 48 may be made of a material, such as rubber or another elastomeric material, providing friction between their outer portions and the web material. Outer portions of the protrusion elements 48 on the second roller 34 overlap partially with outer portions of the protrusion elements 48 on the third roller 36 with a radial overlap length forming an undulated passage for a web material between the second and third rollers 34, 36. The radial overlap length may be between 2-40 mm, preferably 2-20 mm, more preferably 3-12 mm, or most preferably between 4-10 mm. Thereby an undulating passage for a web material may be formed between the second and third rollers 34, 36 such that the shape of the passage for a web material formed between the protrusion elements is meandering along an imaginary line extending along a width direction. The undulated passage forms a friction nip, in which the second and third rollers 34, 36 engage frictionally with the web material passing there through. Due to the frictional engagement of the web material, a sheet of web may be separated from the tail of web material in the separation unit 46 along a perforation of the web material as a user pulls on the web material to dispense a sheet of web.

(40) Due to the adjustable distance between the rotational axes of the second and third rollers the radial overlap length in the undulating passage is variable. The distance between the rotational axes may be chosen such that an undulating passage providing an optimal pinch force is achieved depending on the type of the web material.

(41) The protrusion elements may be of any suitable shape. Thus, the protrusion elements may be in the form of disc elements, propeller-shaped elements, cylinder elements or the like. The cross-section in a radial plane of the protrusion elements may be rounded at the outer periphery of the protrusion element. The cross-section at the outer periphery of the protrusion element may also be rectangular, triangular, wavy or the like. The protrusion elements may be covered by a sleeve or ring of an elastomeric material encircling the outer periphery of each individual protrusion element. The elastomeric material may be glued, vulcanized or simply stretched around the outer portion of the protrusion element.

(42) The maximum radial extensions of the protrusion elements may be equal to or greater than the widths of said protrusion elements. The more the difference between the maximum radial extensions and the widths of the protrusion elements, the greater the undulation amplitude of the passage formed between the protrusion elements. This, in turn, means that with increasing undulation amplitude the pinch force increases. The spacing of the protrusion elements may be the same along the width direction of the first and/or said second roller. Also, the spacing of the protrusion elements may vary along the width direction of the first and/or said second roller. That is, the protrusion elements may be uniformly or non-uniformly distributed along the first and/or second roller. Thus, the protrusion elements may be sparsely arranged in the central portion of the rollers, and concentrated in the peripheral portions of the rollers. If such an arrangement is used, a wrinkleless portion of the web material in the central portion of the roller may be more suitable for gripping by the user when the web material is to be separated.

(43) In the dispensers described above and illustrated in FIGS. 1-4B the first unit 61 and the second unit 62 of the separation unit 60 are adapted such as to cooperate to enable proper dispensing of individual sheet of web material, with proper tearing of the web along perforated lines, while at the same time a relatively low pull force needs to be applied to a free end of the web. The first unit 61 and the second unit 62 both contribute to the pull force required to pull web material out of the dispensing opening 12. The first unit 61 is arranged to contribute a resistance force against movement of the web material which has to be overcome by a first pull force required to pull the web material downstream of the first unit 61. This first pull force is influenced by parameters such as the rotational friction of the third roller 38, the surface friction causing friction between the surface of the third roller 38 and the magnitude of the tensioning force provided by the first unit 61.

(44) A second pull force is defined as the pull force required for pulling the web material downstream the second unit 62. Therefore, both the first and the second units 61, 62 influences the magnitude of the second pull force. The first unit 61 contributes to the first pull force as defined above. The second unit 62 contributes to the second pull force by e.g. its relative position with respect to the first unit 61 and by the specific arrangements of the components of the second unit 62, such as the rotational friction of the second and third rollers 34, 36, the friction between the web material and the protruding elements 48, and the size of the gap allowing passage of the web material. Thereby, the first and second units 61, 62 cooperate to have a combined effect to the dispensing mechanism of the web material.

(45) The separation unit 60 is adapted such that the first pull force is in the range of 20 to 50% of the second pull force. Preferably, the first pull force is 30 to 40% of the second pull force. The second pull force is less than 6N, preferably less than 5N, most preferred less than 4N, and is thereby less than the pull force required to manually separate a sheet from the stack, when the stack is resting freely.

(46) Thus, by using the separation unit according to the present invention, the risk that any given preformed perforation line would break before that particular perforation line has reached the dispensing opening is reduced. At the same time, the separation unit according to the present invention facilitates the separation of the web material such that the force needed for separation of the web material is reduced.

(47) The first and second pull forces are defined as measured according to a pull force measurement method as follows, for web material comprising perforation lines dividing the web material into individual products, e.g. as illustrated with reference to FIG. 5, in the dispenser illustrated with reference to FIG. 3. Also, the perforation strength of the web material, i.e. the strength of the perforation lines, may be measured according to the method as follows.

(48) Force Gauge used: Mecmesin BFG 50 N

(49) Clamp, small (3×1 cm)

(50) General Description of Method:

(51) The method is to be performed in an environment with 50% RH, at 23° C. The web material is to be conditioned in this environment for 24 hours before the method is performed. For further information, reference is made to the ISO-187 standard.

(52) Always attach the clamp (about 1 cm from the edge of the refill) and then pull the refill by at an even speed similar to the speed used when dispensing (.sup.˜1 m/s). The force Gauge should be set to register the maximum force during the pull. Do 10 tests in the same way and note the values. Note any tabbing or tearing or failures that may occur. Always zero the instrument before measuring.

(53) 1. Measure the Perforation Strength of the Web Material.

(54) a. Place the web material on a smooth flat surface. To lock the web material in place, put a weight (or clamp) on the web beyond a first perforation line. Attach the clamp and zero the force gauge, then pull slowly (.sup.˜1 m/s). Register the maximum force which is reached when a perforation line breaks. b. Move the web material forward and put the weight beyond the next product. Then attach the clamp and pull in the same manner as before and register the maximum force when the next perforation line breaks. c. Repeat the above steps until you have at least 10 recorded perforation strengths. Calculate the average perforation strength.
2. Measure the Pull Force Downstream the First Unit a. Arrange the web material in the dispenser, along the web path so as to extend through the first unit. b. Measure downstream the first unit and upstream the second unit by attaching the force gauge clamp to the web material, zero the instrument and pull straight down about 50 cm at a slow speed (1 m/s). Register the maximum force. c. Repeat the above step until you have at least 10 recorded pull force values. Calculate the average pull force value.
3. Measure the Pull Force Downstream the Second Unit, a. Arrange the web material in the dispenser, along the web path so as to extend through the first unit and the second unit. b. Measure downstream the second unit by attaching the force gauge clamp to the web material, zero the instrument and pull straight down at a slow speed (1 m/s) until a perforation line breaks. Register the maximum force. Note any tabbing and tearing. Note any failures to break the perforation (double dispensing). c. Repeat the above step until you have at least 10 recorded pull force values. Calculate the average pull force value.

(55) FIG. 5 illustrates schematically a cross section through a stack 8 of web material according to embodiments. The stack 8 is adapted for being placed in a stack position 10 of a dispenser 2 according to any one of FIGS. 1 to 3. A tail 21 of web material from the stack 8 is threaded along a web path of a relevant dispenser 2. The web material in the stack 8 of web material is a continuous web material which is Z-folded in an accordion-like manner. The web material comprises a first web 50 divided into sheet products defined between subsequent perforation lines 52, extending across the first web 50. The web material further comprises at least one second web 54 divided into individual products defined between subsequent perforation lines 56 extending across the second web 54. The first and second webs 50, 54 are interfolded so that the perforation lines 52 of the first web 50 are offset from the perforation lines 56 of the second web 56 in a longitudinal direction of the first web 50.

(56) The web material may comprise a plurality of individual web sections interconnected by connecting members 58. Thereby, separate stacks 8 of web material may be interconnected to form one large stack. To this end, at one end or at both ends of the stack 8, the stack 8 may be provided with connecting members 58 for interconnecting the web material of one stack 8 with that of a further stack 8. The connecting members may comprise an adhesion arrangement, or preferably, mechanical arrangements such as hook- and loop interconnections. Thus, replenishing a dispenser 2 with stacks 8 of web material may be facilitated. These connecting members 58 provide the intermittent thickness variations to the web material discussed above.

(57) Advantageously, the perforation lines are formed by alternating bonds and slots. It has been found that a remaining bonded length being the total bond length/(total bond length+total slot length) is between 4% and 50%, preferably between 4% and 25%, most preferred between 4% and 15%, is suitable for the most relevant applications of the stack.

(58) The total bond length/(the total bond length+total slot length) may be used as an indication of the strength of the perforation line. It is desired to provide perforation lines which are strong enough to enable feeding of the web material from the stack in a suitable dispenser, but which are also weak enough to enable separation of the sheets. In this context, it is known that other parameters will also influence the strength of the perforation line, such as the paper quality, and the size, shape and distribution of the slots and tabs. The above-mentioned measure may therefore be useful for guiding the person skilled in the art when selecting suitable perforation lines.

(59) However, for determining the “perforation strength” of the perforation lines, the remaining bonded length measure is inadequate, and instead the method to measure the perforation strength as described in the above should be used.

(60) Example embodiments described above may be combined as understood by a person skilled in the art. It is also understood by those skilled in the art that the dispenser proposed herein comprising resilient units may be used with a stack of non-perforated web material, in which case a separation unit comprising a cutting element may be provided in the dispenser. The cutting element may for instance be a cutting knife, a rotating cutting cylinder, or a serrated edge.

(61) Although the invention has been described with reference to example embodiments, many different alterations, modifications and the like will become apparent for those skilled in the art. For instance, each one of the first and second layers of the web material may comprise one or more sub-layers. The sub-layers may be at least partially connected to each other. The web material in a stack of continuous web material may be V-folded or W-folded in an accordion-like manner.

(62) Therefore, it is to be understood that the foregoing is illustrative of various example embodiments and that the invention is defined only the appended claims.

(63) As used herein, the term “comprising” or “comprises” is open-ended, and includes one or more stated features, elements, steps, components or functions but does not preclude the presence or addition of one or more other features, elements, steps, components, functions or groups thereof.