STACK OF PAPER SHEETS, DISPENSER HAVING SUCH A STACK AND METHOD FOR FORMING SUCH A STACK

Abstract

A stack of paper sheets, particularly for use as dispenser napkins, includes a plurality of folded sheets. Each folded sheet is folded along a first folding line so that a part of a free edge opposite to the first folding line is located on an outer surface of the folded sheet and inward of the outer peripheral edges of the folded sheet, whereby a starter fold is formed. Each folded sheet is further folded along a second folding line non-parallel to the first folding line, the second folding line separating the folded sheet in two panels connected at the second folding line. Two consecutive folded sheets are interfolded so that one panel of one folded sheet is disposed between two panels of the consecutive folded sheet. Also, a method for manufacturing such a stack and folding the sheets included in the stack as well as a dispenser containing such a stack are disclosed.

Claims

1. A stack of paper sheets for use as napkins, comprising: a plurality of folded sheets, wherein each folded sheet is folded along a first folding line so that a part of a free edge opposite to the first folding line is located on an outer surface of the folded sheet and inward of outer peripheral edges of the folded sheet to form a starter fold, wherein each folded sheet is further folded along a second folding line non-parallel to the first folding line, the second folding line separating the folded sheet in two panels connected at the second folding line, wherein two consecutive folded sheets are interfolded so that one panel of one folded sheet is disposed between two panels of the consecutive folded sheet, and wherein each folded sheet is further folded along a third folding line parallel to the first folding line forming a backfold, the backfold and the starter fold being located on opposite sides of an intermediate sheet before being folded about the second folding line.

2. The stack according to claim 1, wherein the first folding line extends perpendicular to the second folding line.

3. The stack according to claim 1, wherein the starter fold extends along the two panels on surfaces of the two panels facing away from each other.

4. The stack according to claim 1, wherein a width of the starter fold perpendicular to the first folding line and a width of the backfold perpendicular to the third folding line sum up to a total width of the folded sheet between the first folding line and the third folding line.

5. The stack according to claim 1, wherein the backfold extends along the two panels on surfaces of the panels facing each other.

6. The stack according to claim 1, wherein the free edge of the starter fold is formed by a fourth folding line.

7. The stack according to claim 6, wherein the fourth folding line is a half fold of a base sheet.

8. The stack according to claim 6, wherein the fourth folding line is parallel to the first folding line.

9. The stack according to claim 1, wherein the folded sheet is folded about two of the second folding lines separating the folded sheet in three panels connected at the second folding lines.

10. A dispenser comprising: a housing for accommodating the stack according to claim 1; and a dispensing opening, the part of the free edge of the starter fold being accessible via the dispensing opening when the stack is accommodated in the housing.

11. A method for forming a stack of folded paper sheets, the method comprising: a) folding a plurality of sheets to form intermediate folded sheets folded along a first folding line so that a free edge opposite to the first folding line is located inward of outer peripheral edges of the intermediate folded sheet to form a starter fold; b) folding the intermediate folded sheets along a second folding line non-parallel to the first folding line to form the folded sheets so that a part of the free edge of the starter fold is located inward of the outer peripheral edges and on an outer surface of the folded sheet, the second folding line separating the folded sheet in two panels connected at the second folding line; c) interfolding two consecutive folded sheets so that one panel of one folded sheet is disposed between the two panels of the consecutive folded sheet; and d) enfolding the sheets along a third folding line parallel to the first folding line forming a backfold so that the backfold and the starter fold are located on opposite sides of the sheet, wherein step d) is performed before step b).

12. A method according to claim 11, further comprising the step of folding the sheets along a fourth folding line before the step a).

13. A method according to claim 11, wherein the sheets are fed in a machine direction and the first folding line is parallel to the machine direction and the second folding line is transverse to the machine direction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Further features, embodiments and examples are explained in the following detailed description referring to the accompanying drawings. The drawings show in:

[0025] FIG. 1 A-C: a process of folding a sheet and forming a stack according to a first embodiment;

[0026] FIG. 2: a perspective view of one folded sheet of the stack of FIG. 1;

[0027] FIG. 3 A-D: a process of folding a sheet and forming a stack according to a second embodiment;

[0028] FIG. 4: a perspective view of one folded sheet of the stack of FIG. 3;

[0029] FIG. 5: a perspective view of one folded sheet of a stack according to a third embodiment;

[0030] FIG. 6: a perspective view of one folded sheet of a stack according to a fourth embodiment;

[0031] FIG. 7: a perspective view of one folded sheet of a stack according to a fifth embodiment;

[0032] FIG. 8: a perspective view of one folded sheet of a stack according to a sixth embodiment;

[0033] FIG. 9: a perspective view of one folded sheet of a stack according to a seventh embodiment; and

[0034] FIG. 10: a schematic side view of the folded sheets of FIG. 9 showing the interfolding.

DETAILED DESCRIPTION OF PARTICULAR EMBODIMENTS

[0035] The same reference numerals have been used for the same or similar elements throughout the various embodiments disclosed in FIGS. 1A to 10. In order to avoid repetition these elements have not always been described anew in all of the embodiments. Further it is noted that folding lines extending in the machine direction (MD) are perpendicular to folding lines extending in the cross machine direction (CD) in the embodiments.

[0036] FIGS. 1A-C and 2 show a first embodiment. Each folded sheet 30 of the first embodiment is ¼ in size compared to the completely unfolded sheet (in the following referred to as base sheet 10).

[0037] FIG. 1A shows a perspective of the base sheet 10. The base sheet 10 has a rectangular shape having a first pair of parallel peripheral edges 11.sup.1 and 11.sup.2 and a second pair of parallel peripheral edges 12.sup.1 and 12.sup.2. The base sheet may be formed of one or more paper plies.

[0038] The base sheet 10 is folded about a first folding line 13 indicated by the broken line in FIG. 1A. In particular, the left hand peripheral edge 12.sup.1 is folded about the first folding line 13 towards an upper surface 14 of the base sheet 10 as indicated by the arrow.

[0039] As a result, a starter fold 16 is formed on the upper surface 14 of the base sheet 10 and later the outer side of the folded sheet 30. The starter fold 16 has a free edge corresponding to the left hand peripheral edge 12.sup.1 and is connected to the remainder of the base sheet 10 at the first folding line 13. The free edge of the starter fold 16 is located within the outline of the thus obtained intermediate folded sheet 20.

[0040] Further, the base sheet 10 is folded about a third folding line 15 indicated by the broken line in FIG. 1A. In particular, the right hand peripheral edge 12.sup.2 is folded about the third folding line 15 towards a lower surface of the base sheet 10 (opposite to the upper surface 14) as indicated by the arrow.

[0041] As a result, a backfold 17 is formed on the back surface of the base sheet 10 and later the inner side of the folded sheet 30. The backfold 17 is connected to the remainder of the base sheet 10 at the third folding line 15. A free edge of the backfold corresponds to the right hand peripheral edge 12.sup.2 of the base sheet 10.

[0042] It is also clear from the above, that the first folding line 13 and the third folding line 15 are parallel to the peripheral edges 12.sup.1 and 12.sup.2.

[0043] In a particular embodiment of the manufacturing process a web having a total width W corresponding to the length of the peripheral edges 11.sup.1 and 11.sup.2 is fed in a machine direction (MD) parallel to the peripheral edges 12.sup.1 and 12.sup.2. Subsequently, a plurality of sheets may be formed by cutting the web in a cross machine direction (CD) to form the peripheral edges 11.sup.1 and 11.sup.2. The folding about the first folding line 13 and the third folding line 15 may be achieved in the machine direction (MD) either concurrently, before or after the mentioned cutting.

[0044] Thus, one obtains an intermediate folded sheet 20 as shown in FIG. 1B.

[0045] Subsequently and as shown in FIG. 1B, the intermediate folded sheet 20 is folded about a second folding line 18 towards the back in FIG. 1B as shown by the arrow. In the manufacturing process, this folding about the second folding line 18 is performed in the cross machine direction (CD). Thereby, the intermediate folded sheet 20 is separated into a first panel 19 and a second panel 21 by the second folding line 18.

[0046] Accordingly a folded sheet 30 as shown in FIG. 2 is obtained. At this stage, the peripheral edges 11.sup.1 and 11.sup.2 may be congruent in plan view. Thus, the outline of the folded sheet 30 is delimited by the first folding line 13, the second folding line 15 parallel thereto, the second folding line 18 perpendicular to the first folding line and the second folding line as well as the peripheral edges 11.sup.1 and 11.sup.2 parallel to the second folding line. Particularly considering FIG. 2, it becomes apparent that the free edge of the starter fold 16 formed by the peripheral edge 12.sup.1 is situated inward of the outer peripheral edges 13, 15, 18, 11.sup.1/2, i.e. the outline of the folded sheet 30. Thus, the free edge may easily be gripped by a user as will be explained in more detail below.

[0047] Further, the upper surface 14 of the base sheet 10 forms the outer surface of the folded sheet 30. The lower surface opposite to the upper surface 14 forms the inner surface of the folded sheet 30. Thus, the two panels 19, 21, connected at the second folding line 18, form a U-shape.

[0048] The back fold 17 is located on an inner surface side. In particular, outer surfaces 22 of the backfold 17 facing away from the back surface of the base sheet 10 face each other but are located on an inner surface side of the folded sheet 30.

[0049] The starter fold 16 is located on an outer surface side. In particular, outer surfaces 23 of the starter fold 16 facing the upper surface 14 of the base sheet 10 face away from each other.

[0050] The folding of the intermediate folded sheet 20 about the folding line 18 is used to interfold a plurality of consecutive folded sheets 30 to form a stack 40 as shown in FIG. 1C.

[0051] In particular and as indicated in FIG. 2, the two panels 21 and 19 sandwich another panel 19′ of a consecutive folded sheet 30′ (the panel 19′ of the consecutive folded sheet 30′ has been indicated only schematically in FIG. 2). In turn, the consecutive folded sheet 30′ sandwiches the panel 19 of the folded sheet 30 and the panel 21″ (not shown) of a further consecutive folded sheet 30″ (not shown) between its panels 19′ and 21′. This is repeated to form the stack 40 of a plurality of folded sheets 30.

[0052] Moreover, the width W1 of the starter fold 16, that is the length of a line perpendicular to and connecting the first folding line 13 and the peripheral edge 12.sup.1 and the width W2 of the backfold 17, that is the length of a line perpendicular to and connecting the third folding line 15 and the peripheral edge 12.sup.2 sum up to the width W3 of the remainder of the base sheet 10, that is the length of a line perpendicular to and connecting the first folding line 13 and the third folding line 15 (W1+W2=W3). It is to be understood that in other embodiments the width W1 and W2 do not need to sum up to the width W3. Accordingly, the planar size of the intermediate folded sheet 20 is 50% as compared to the planar size of the base sheet 10. Further, in particular embodiments, the free edge of the starter fold 16 and the free edge of the backfold 17 are congruent in plan view. As a result, the number of layers formed by the plurality of folded sheets 30 over the height H of the stack 40 is the same over the whole planar area of the stack 40. In particular, the number of layers per folded sheet in the height direction is four over the entire planar area. Thereby, a stable and easily compressible stack 40 is achieved.

[0053] As will be apparent from FIG. 1A, the width W1 is smaller than the width W2. Accordingly, the free edge of the starter fold 16 formed by the peripheral edge 12.sup.1 will be located closer to the peripheral edge (formed by the first folding line 13) of the intermediate folded sheet 20 than to the opposite peripheral edge (formed by the third folding line 15) of the intermediate folded sheet 20. Accordingly, the free edge is off-centered. If the width W1 and W2 is the same and W1+W2=W3 and/or if the width W1 is half the width W3, the free edge is centered.

[0054] Further, by folding the intermediate folded sheet 20 about the folding line 18, which is disposed in the center of the intermediate folded sheet 20, the planar size of the folded sheet is reduced to 50% of the planar size of the intermediate folded sheet 20 and to 25% of the planar size of the base sheet 10. Thus, a stack 40 with a relatively small footprint in plan view can be obtained, which in the present example is only ¼ of the original planar size of the base sheet 10. This size reduction is however mainly achieved by folding lines having a further function, namely the function of forming the starter fold 16 (the first folding line 13) and the function of interfolding the consecutive folded sheets 30 (the second folding line 18). Thus, these folding lines have a double function.

[0055] The stack may be accommodated in a dispenser 41 as schematically indicated in FIG. 1C. The dispenser 41 has a dispensing opening 42, which in the present example may be situated at an outer edge of the dispenser 41 in a plan view.

[0056] The dispenser 41 as shown in FIG. 1C may have been refilled with a stack 40 recently so that no folded sheet 30 protrudes from the dispensing opening 42. Yet, the free edge of the starter fold 16 formed by the peripheral edge 12.sup.1 is visible and accessible through the dispensing opening 42. If a user intends to withdraw a folded sheet 30 from the dispenser 41, the user can thus readily grab the free edge of the starter fold 16 and withdraw the folded sheet 30 through the dispensing opening 42 and from the dispenser 41. Because of friction forces between the panel 19′ of the consecutive folded sheet 30′ and the inner surfaces of the panels 19 and 21 of the folded sheet 30, the panel 19′ of the consecutive folded sheet 30′ is entrained by the withdrawal of the folded sheet 30. As a result, after complete withdrawal of the folded sheet 30, the panel 19′ of the consecutive folded sheet 30′ protrudes from the dispensing opening 42. Thus, the consecutive folded sheet 30′ can be withdrawn even more easily. This process is continued as long as the folded sheets 30 are interfolded. If more than one stack 40 is disposed within the dispenser 41, with the last sheet of the first stack and the first folded sheet of the second stack not being interfolded, the first folded sheet of the second stack will again not protrude from the dispensing opening 42. Yet, in this case, the user can again grab the starter fold 16 of the first folded sheet of the second stack as explained above.

[0057] In addition, when withdrawing the folded sheet 30 from the dispenser 41, the folded sheet 30 is automatically unfolded about the first folding line 13, the second folding line 18 and the third folding line 15. By unfolding about the second folding line 18, the folded sheet 30 already doubles its size again to the intermediate folded sheet 20. The unfolding about the first folding line 13 and the third folding line 50 again doubles the size of the intermediate folded sheet 20 to the full size of the base sheet 10. Accordingly, the user can automatically get the benefit of the full area of the base sheet 10 without having to manually unfold the sheet/napkin.

[0058] FIGS. 3A-D and 4 show a second embodiment. Each folded sheet 30 of the second embodiment is ⅛ in size compared to the completely unfolded base sheet 10.

[0059] The main difference between the first and second embodiment is, that the base sheet 10 is in a first step, shown in FIG. 3A, folded about a fourth folding line 50 in half as shown by the arrow. Thus, the planar size of the thus folded intermediate folded sheet 1 is reduced by 50% compared to the planar size of the base sheet 10. In the manufacturing process, the fourth folding line 50 is as well created in the machine direction (MD), yet before the formation of the first folding line 13 and the third folding line 15.

[0060] The intermediate folded sheet 1 shown in FIG. 3B is in principle similar to the base sheet 10 in FIG. 1A except that it is double layered because of the folding about the fourth folding line 50. As a result, the free edge of the starter fold 16 is formed by the fourth folding line 15. As a consequence, the starter fold 16 is double layered (see FIG. 4) and the free edge is “closed” in that the two layers of the starter fold 16 are connected by the fourth folding line 50. This configuration provides for a more stable starter fold 16 which is easy to grab.

[0061] To the contrary, the free edge of the backfold 17 is formed by the aligned peripheral edges 12.sup.1 and 12.sup.2 of the base sheet 10. Hence, also the backfold 17 is double layered, but the free edge thereof is “open” in that the two layers are unconnected.

[0062] After folding about the first folding line 13 and the third folding line 15, one obtains a further intermediate folded sheet 20 as shown in FIG. 3C in principle corresponding to the intermediate folded sheet 20 of FIG. 1B. The further intermediate folded sheet 20 is because of W1+W2=W3 only 50% in planar size of the intermediate folded sheet 1 and hence only 25% in plan a size of the base sheet 10.

[0063] In a next step and as explained with respect to the first embodiment above, the further intermediate folded sheet 20 is then folded about a second folding line 18 extending in the cross machine direction (CD). Thus, the size of the further intermediate folded sheet 20 is further reduced by 50% to obtain the folded sheet 30. In total, the folded sheet 30 is accordingly only 12.5% in planar size of the base sheet 10 in this embodiment.

[0064] In addition and as in the first embodiment, the folding about the second folding line 18 serves to interfold a plurality of folded sheets 30 to form a stack 40 as shown in FIG. 3D.

[0065] Again because of the configuration of the width W1, W2 and W3, the number of layers over the height H of the stack is the same. In the particular example, the number of layers per sheet is eight over the whole planar area of each folded sheet 30.

[0066] The remainder of the second embodiment is the same as that of the first embodiment and reference is made to the above description.

[0067] A third embodiment is shown in FIG. 5. The embodiment in FIG. 5 differs over the first embodiment only in that the backfold 17 is omitted. To put it differently, the base sheet 10 is only folded once about the first folding line 13 and no folding about the third folding line 15 is performed. The width W1 of the starter fold 16 may be increased compared to the first and second embodiment to half the width W3 of the remainder of the base sheet 10. Accordingly, the free edge formed by the peripheral edge 12.sup.1 is located in the center of the folded sheet 30 in plan view, that is centrally between the folding line 13 and the peripheral edge 12.sup.2.

[0068] In this example, the planar size of the base sheet 10 is reduced by ⅓ when folding the base sheet 10 about the first folding line 13 for forming the starter fold 16. Accordingly, the size of the intermediate folded sheet 20 in this embodiment is about 66% of that of the base sheet 10.

[0069] Afterwards, the intermediate folded sheet 20 is again folded about the second folding line 18 used for interfolding as in the first and the second embodiment. Thereby, the planar size of the folded sheet 30 is only 50% of the planar size of the intermediate folded sheet 20 and only ⅓ (about 33.3%) of the planar size of the base sheet 10.

[0070] A fourth embodiment is shown in FIG. 6. As explained with respect to the second embodiment, in this embodiment the starter fold 16 is double layered to provide for a more stable starter fold 16 which is hence easier to be grabbed. The fourth embodiment provides an alternative to achieve such a starter fold 16 even without first folding the base sheet 10 into half as in FIG. 3A of the second embodiment.

[0071] Similar to the first embodiment one starts from a base sheet 10, folding the base sheet 10 about a first folding line 13 and a third folding line 15. The first folding line 13 and the third folding line 15 separate the base sheet 10 into 3 portions of equal width W1=W2=W3.

[0072] Subsequently, the portion folded about the first folding line 13 is again folded in half about a fifth folding line 51 in an opposite direction. The fifth folding line 51 is parallel to the first folding line 13 and hence also the third folding line 15. Accordingly, a starter fold 16 having a width W4=0.5*W1 is formed.

[0073] The free edge of the starter fold 16 is formed by the fifth folding line 51. Hence, the free edge is, as in the second embodiment, “closed” in that the two layers forming the starter fold 16 are connected at the fifth folding line 51. In this embodiment, the free edge of the starter fold 16 is again centered relative to the outline between the first folding line 13 and the third folding line 15.

[0074] Further and different to the first embodiment, the backfold 17 extends over the entire inner side of the panels 19, 21. That is, the width W2 of the backfold 17 is the same as the width W3 of the remainder of the folded sheet 30.

[0075] The planar size of the folded sheet 30 is, in this embodiment, ⅙ of the size of the base sheet 10.

[0076] A fifth embodiment is shown in FIG. 7. The fifth embodiment differs from the fourth embodiment only in that also the backfold 17 is folded in half similar to the starter fold 16 in the fourth and the fifth embodiment. For this purpose, the backfold 17 is after being folded about a third folding line 15 folded in half about a sixth folding line 52 in an opposite direction. Accordingly, the width W5 of the backfold 17 is 0.5*W2 (W5=0.5*W2). The benefit of this fifth embodiment compared to the fourth embodiment is that the same number of layers may be achieved over the height H of the stack and over the entire planar area thereof. In particular and considering FIG. 7, the number of layers per sheet 30 is six over the whole width W3. To the contrary, the number of layers in the fourth embodiment in FIG. 6 is six in the left portion of the width W3 and four in the right portion of the width W3 (the left and right portion are divided in the center of the width W3). Accordingly, the stack formed from sheets 30 as shown in the fifth embodiment would be more stable and can be more easily compressed as compared to the one shown in the fourth embodiment.

[0077] The planar size of the folded sheet 30 is, in this embodiment again, ⅙ of the size of the base sheet 10.

[0078] A sixth embodiment is shown in FIG. 8. The sixth embodiment differs from the first embodiment in that the intermediate or middle portion having the width W3 of the base sheet 10 is folded about a seventh folding line 53 and an eighth folding line 54 to ⅓ of its size. In particular, the seventh folding line 53 and the eighth folding line 54 separate the middle portion of the base sheet 10 in three portions of equal width (W3=3*W6). Accordingly and as compared to the first embodiment, the footprint of the folded sheet 30 can be further reduced. In particular, the planar size of the folded sheet 30 is only ⅛ of the planar size of the base sheet 10.

[0079] That remainder of the sixth embodiment is the same as that of the first embodiment.

[0080] Moreover and as will be apparent from the comparison of the first and second embodiments above, any of the third to sixth embodiment may additionally include first folding the base sheet 10 into half along the fourth folding line 50 and only subsequently starting with the folding process described in these embodiments.

[0081] In addition, it is to be understood that in view of the description above the first folding line 13 may be selected so that the free edge of the starter fold 16 is centered or off-centered in all of the above embodiments. Further and if a backfold 17 is present, the width of the backfold 17 can be adjusted as desired. Yet, to achieve the same number of layers over the height H of the stack 40, the width of the backfold 17 is the same as the width of the starter fold 16. In particular embodiments, the free edges of the starter fold 16 and the backfold 17 are aligned or congruent in plan view.

[0082] Moreover, the interfolding has been explained with respect to a U-folded sheet 30. Yet, the interfolding can also be achieved when the intermediate folded sheet 20 is folded in opposite directions about parallel but distanced second folding lines 18, whereby a Z-folded sheet is obtained similar to that described in US 2014/0057069 A1. Such an embodiment is shown in FIGS. 9 and 10. This embodiment is similar to the one described with respect to FIGS. 3 and 4 with the exception that the intermediate folded sheet 20 shown in FIG. 3C is folded twice about two parallel second folding lines 18. Accordingly and considering the folded sheet 30, a part of the outer surface 23 and, hence, of the free edge 50 of the starter fold 16 is located on the top of the folded sheet 30 in the stack and hence faces upward in the stack. In other words, the free edge 50 of the starter fold 16 is located on top of the top panel 62. The remainder of the starter fold 16, i.e. of the outer surface 23 and the free edge 50, are located on an inner side surface of the folded sheet 30 between the intermediate panel 60 and the bottom panel 61. Similar, the backfold 17 or more particularly its outer surface 22 is located on an inner side surface of the folded sheet 30 between the top panel 62 and the intermediate panel 60 whereas the remainder of the backfold 17 is located on an outer side surface of the folded sheet 30, namely the bottom surface of the bottom part 61 and the facing downward in the stack.

[0083] The interfolding of such folded sheets 30 is shown in FIG. 10. In particular, one panel, namely the bottom panel 62, of one folded sheet 30 is sandwiched between 2 panels, namely the top panel 61 and the intermediate panel 60 of the consecutive folded sheet 30 and so on. Yet, the interfolding can also be performed as shown in US 2014/0057069 A1 we see intermediate panel 60 and the bottom panel 62 of one folded sheet 30 being sandwiched between the top panel 61 and the intermediate panel 60 of the consecutive folded sheet 30 and so on.

[0084] The remainder of this embodiment is the same as that shown in FIGS. 3 and 4. Of course also the embodiment in FIGS. 1 and 2 and the embodiments in FIGS. 5 to 8 may be embodied in combination with a Z-fold about two second folding lines 18 as shown in FIGS. 9 and 10.

[0085] In view of the above, the described embodiments are not considered exclusive but may be modified and even combined in various ways.