Abstract:
By controlling the profile of a folded stack when placed into an oval dispenser, it is possible to reduce the compression of the folded stack by the dispenser&#39;s sidewall, thereby reducing or eliminating sheet tears when dispensing the sheet-material from the dispenser. In particular, by making the folded stack thicker in the middle and thinner at the edges, as a result of providing a variable width flat stack prior to folding the flat stack, the folded stack will better fit into an oblong or circular dispenser.

Description:
BACKGROUND 
     Increasingly, producers of sheet dispensers, such as facial tissue cartons, are interested in alternative shapes besides the typical parallelepiped shapes generally offered. A parallelepiped (rectangular prism) dispenser shape can offer several advantages, such as efficient packing of the product, efficient distribution of the product, and efficient board utilization to make the carton. However, consumers have grown accustomed to such shapes and there is little differentiation from one product to another. Graphical treatments can help, but the basic dispenser shapes are still largely the same for all manufacturers. 
     One common tissue dispenser is an upright carton having a cubical shape containing an inverted U-shaped, V-folded, interleaved stack of facial tissues. An upright carton typically has a square top and bottom having dimensions of approximately 4.4 inches by 4.4 inches. The height of the upright tissue carton is approximately 5 inches. When this tissue packaging was first introduced by Kimberly-Clark Corporation many years ago, it was a unique and differentiated packaging format to the traditional flat, rectangular tissue cartons. As such, it drove consumer interest, enabling Kimberly-Clark Corporation to offer the packaging format as a premium product. Patent protection for the upright tissue carton and the tissue stack folding method has expired, enabling many other manufacturers to enter the market. 
     Alternatively shaped tissue dispensers to the ubiquitous flat or upright tissue cartons could offer an advantage in product differentiation. Alternatively shaped tissue dispensers could be offered as a new premium product and upright tissue dispensers as a mid-tier product. However, alternatively shaped dispensers are typically not as well suited to the size of standard tissue stacks, which often fit better and dispense better from the traditional shapes. For example, dispensers having an oval cross section can provide a distinctive look, but the depth of the oval dispenser as measured from the front face can be less than the 4.4 inch depth in an upright tissue carton. The decreased depth can significantly reduce the number of sheets that can fit into the oval dispenser and/or cause dispensing problems (sheet tears, multiple dispensing, and sheet fallback) when dispensing. Dispensing problems can cause a perception of poor quality in the mind of the user/purchaser, making it more difficult to position an oval shaped dispenser as a premium product. 
     Therefore, a need exists for dispenser shapes that are significantly differentiated from existing upright or rectangular tissue carton shapes; yet, at the same time, can dispense tissue stacks as well or better than current upright or rectangular dispensers for a similar sheet count stack. Furthermore, a need exists for packaging the same number of tissue sheets in an oval or circular dispenser as currently placed into existing upright dispensers without increasing the incidence of dispensing failures. 
     SUMMARY 
     The inventors have discovered that by controlling the profile of the folded stack when placed into an oval or circular dispenser, it is possible to reduce the compression of the folded stack by the dispenser&#39;s sidewall, thereby reducing or eliminating sheet tears when dispensing the sheet-material from the dispenser. In particular, by making the folded stack thicker in the middle and thinner at the edges, the folded stack will better fit into an oblong dispenser having an oval top and bottom. 
     Hence, in one aspect, the invention resides in a product including: a flat stack of a plurality of folded sheets formed from a sheet-material, the flat stack having a variable width and a substantially uniform length, the flat stack having an upper portion and a lower portion; the flat stack folded about a transverse fold axis to form a folded stack having an arched stack top and a stack bottom comprising two legs; and the folded stack placed into a dispenser. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above aspects and other features, aspects, and advantages of the present invention will become better understood with regard to the following description, appended claims, and accompanying drawings in which: 
         FIG. 1  is a perspective view showing one embodiment of the sheet-material dispenser of the present invention. 
         FIG. 2  is a top view of  FIG. 1  prior to opening the sheet-material dispenser. 
         FIG. 3  is a perspective view of one embodiment of a stack containing a plurality of sheets formed from a sheet-material. 
         FIG. 3A  is a partially exploded end view of the stack of  FIG. 3  showing a fold configuration for the plurality of sheets. 
         FIG. 3B  is a perspective view of the stack of  FIG. 3  folded about a transverse fold axis. 
         FIG. 3C  is a top view of the sheet-material dispenser of  FIG. 1  with the top removed and the folded stack of  FIG. 3B  inserted into the dispenser. 
         FIG. 4  is a perspective view of another embodiment of a stack containing a plurality of sheets formed from a sheet-material. 
         FIG. 4A  is a partially exploded end view of the stack of  FIG. 4  showing a fold configuration for the plurality of sheets. 
         FIG. 4B  is a top view of the sheet-material dispenser of  FIG. 1  with the top removed and the stack of  FIG. 4  folded about a transverse fold axis and inserted into the dispenser. 
         FIG. 5  is a perspective view of another embodiment of a stack containing a plurality of sheets formed from a sheet-material. 
         FIG. 5A  is a partially exploded end view of the stack of  FIG. 5  showing a fold configuration for the plurality of sheets. 
         FIG. 5B  is a top view of the sheet-material dispenser of  FIG. 1  with the top removed and the stack of  FIG. 5  folded about a transverse fold axis and inserted into the dispenser. 
         FIG. 6  is a perspective view of another embodiment of a stack containing a plurality of sheets formed from a sheet-material. 
         FIG. 6A  is a partially exploded end view of the stack of  FIG. 6  showing a fold configuration for the plurality of sheets. 
         FIG. 6B  is a perspective view of the stack of  FIG. 6  folded about a transverse fold axis. 
         FIG. 6C  is a top view of the folded stack of  FIG. 6B  inserted into a dispenser having a circular cross section. 
     
    
    
     Repeated use of reference characters in the specification and drawings is intended to represent the same or analogous features or elements of the invention in different embodiments. 
     DEFINITIONS 
     As used herein, forms of the words “comprise”, “have”, and “include” are legally equivalent and open-ended. Therefore, additional non-recited elements, functions, steps or limitations may be present in addition to the recited elements, functions, steps, or limitations. 
     As used herein, “sheet-material” is a flexible substrate, which is useful for household chores, cleaning, personal care, health care, food wrapping, and cosmetic application or removal. Non-limiting examples of suitable substrates for use with the dispenser include nonwoven substrates; woven substrates; hydro-entangled substrates; air-entangled substrates; paper substrates comprising cellulose such as tissue paper, toilet paper, or paper towels; waxed paper substrates; conform substrates comprising cellulose fibers and polymer fibers; wet substrates such as wet wipes, moist cleaning wipes, moist toilet paper wipes, and baby wipes; film or plastic substrates such as those used to wrap food; and shop towels. Furthermore, laminated or plied together substrates of two or more layers of any of the preceding substrates are also suitable. 
     As used herein, “wet sheet-material” includes substrates that are either wet or pre-moistened by an appropriate liquid, partially moistened by an appropriate liquid, or substrates that are initially dry but intended to be moistened prior to use by placing the substrate into an appropriate liquid such as water or a solvent. Non-limiting examples of suitable wet substrates include a substantially dry substrate (less than 10% by weight of water) containing lathering surfactants and conditioning agents either impregnated into or applied to the substrate such that wetting of the substrate with water prior to use yields a personal cleansing product. Such substrates are disclosed in U.S. Pat. No. 5,980,931 entitled Cleansing Products Having A Substantially Dry Substrate, issued to Fowler et al. on Nov. 9, 1999. Other suitable wet sheet-materials can have encapsulated ingredients such that the capsules rupture during dispensing or use. Other suitable wet sheet-materials include dry substrates that deliver liquid when subjected to in-use shear and compressive forces. Such substrates are disclosed in U.S. Pat. No. 6,121,165 entitled Wet-Like Cleaning Articles, issued to Mackay et al. on Sep. 19, 2000. 
     DETAILED DESCRIPTION 
     It is to be understood by one of ordinary skill in the art that the present discussion is a description of exemplary embodiments only and is not intended as limiting the broader aspects of the present invention, which broader aspects are embodied in the exemplary construction. 
     Referring now to  FIGS. 1 and 2 , one embodiment of an oblong dispenser  10  is illustrated. The dispenser includes a top  12 , a bottom  14 , and a sidewall  16 . The dispenser has a maximum length, Ld, measured along a dispenser longitudinal axis  18 , and a maximum width, Wd, measured along a dispenser transverse axis  19 . The dispenser is oblong with the dimension for Ld greater than the dimension for Wd. As used herein, “maximum” for a length, width, or height dimension is used to refer to the greatest dimension of the object in that specific direction when the shape of the object is such that it has a variable length, width, or height from the use of curved or tapered portions, for example. Maximum does not mean that the dimension referred to may not exceed a given dimension. Another embodiment of the object may have a different maximum length, width, or height. 
     In one embodiment of the oblong dispenser, the top and the bottom ( 12 ,  14 ) comprised an oval shape and the oval dispenser had a maximum length, Ld, of 5 and ⅞ inches and a maximum width, Wd, of 3 and ⅞ inches. An oval sheet-material dispenser is a visually striking and an alternatively shaped dispenser to the square or rectangular facial tissue boxes currently offered. In other embodiments of the dispenser, at least a portion of the sidewall  16  can be curved such as a racetrack dispenser having a curvilinear sidewall  16  with curved end portions and linear front and back faces. Such a dispenser from the top resembles a speed skating ice rink. In another embodiment, the entire sidewall  16  can be curved with the sidewall  16  not having any linear portions. In other embodiments, the oblong dispenser can have four substantially flat sidewall panels connected by curved sections or the oblong dispenser can be an elongated hexagonal shape, or other polygon shape. 
     Referring now to  FIGS. 3 ,  3 A,  3 B, and  3 C, a flat stack  20  of a plurality of individual folded sheets  22  of a sheet material  24  having substantially the same unfolded sheet width is illustrated. The flat stack  20  has a substantially uniform maximum length, Ls, measured along a stack longitudinal axis  26 , and a variable width, W, measured in the direction of a stack transverse fold axis  28 . In particular, an upper portion  29  of the flat stack  20  has a smaller width, Wu, than a lower portion  30  of the flat stack. The difference between the widths of Wu and Wl can be created by folding the same width sheets  22  along the longitudinal axis in the upper portion  29  with more folds than the number of folds along the longitudinal axis for the sheets in the lower portion  30 . For example, the sheets  22  in the upper portion  29  could be W-folded and the sheets in the lower portion  30  Z-folded or V-folded. Alternatively, the upper portion  29  could be Z-folded and the lower portion  30  could be V-folded. 
     In one embodiment as best seen in  FIG. 3A , the flat stack  20  contained individual tissue paper sheets  22  that are folded and interleaved for pop-up dispensing. During pop-up dispensing, withdrawing one sheet from the dispenser pulls at least a portion of the next sheet out of the dispenser for easier access to the next sheet. In the illustrated embodiment, the upper portion  29  of the flat stack  20  includes a plurality of Z-folded sheets having a leading panel  31 , a center panel  32 , and a trailing panel  33  separated by two fold lines  41 . The leading panel  31 , center panel  32 , and trailing panel  33  are approximately equal in width. The Z-folded sheets are interleaved, with the leading panel  31  of a subsequent sheet placed between the center panel  32  and the trailing panel  33  of a preceding sheet. The lower portion  30  of the flat stack includes a plurality of V-folded sheets having a leading panel  31  and a trailing panel  33  separated by a fold line  41 . The V-folded sheets are interleaved, with the leading panel  31  of a subsequent sheet placed between the leading panel  31  and trailing panel  33  of a preceding sheet. The leading panel  31  and trailing panel  33  are approximately equal in width. At the interface between the upper portion  29  and the lower portion  30 , the transition sheet  40  is Z-folded with a shorter leading panel  31  and longer center and trailing panels ( 32 ,  33 ) to smoothly transition from the upper Z-fold to the lower V-fold. 
     Referring to  FIGS. 3B ,  3 C, and  2 , after assembling the flat stack  20  of interfolded sheets  22 , the flat stack is folded approximately 180 degrees about the stack transverse fold axis  28  adjacent the lower portion  30  to form a folded stack  34  having an arched stack top  36  and a stack bottom  37  comprising two opposing legs  38  located on opposite sides of the transverse fold axis  28  and extending there from. The folded stack  34  is then inserted into the oval dispenser  10  such that the transverse fold axis  28  is substantially parallel to the dispenser longitudinal axis  18  with the stack bottom  37  adjacent the dispenser bottom  14 . 
     As seen in  FIG. 3C , this results in the folded stack  34  substantially filling out the interior length and width of the oval dispenser  10  without the folded stack  34  being unduly compressed by the oval dispenser&#39;s sidewall  16 . Since the upper portion  29  of the folded stack  34  is narrower, it fills in the wider center section of the oval dispenser  10 . The thickness of the folded stack  34  is reduced near the narrower end portions of the oval dispenser  10  thereby reducing compression while dispensing the initial sheets; especially at the edges  39  of the folded stack  34  where the fold lines  41  are located. Sheet-material  24  that would have been excessively compressed at the edges  39  has been relocated to the wider center section of the oval dispenser. As such, improved dispensing occurs because the initial sheets in the folded stack are compressed much less by the oval sidewall  16  when the same number and equivalent thickness sheets comprise the folded stack  34  as opposed to the same number of sheets formed into an entirely V-folded interleaved folded stack  34 . 
     It is believed one of the primary causes of sheet dispensing failures in oval dispensers containing folded stacks  34  is tearing of the initial sheets upon withdrawing them from the dispenser. Sheet tears are believed to occur by attempting to place too many individual sheets in the folded stack  34 , thereby increasing its overall size such that it must be significantly compressed by the sidewall  16  in order to fit into the oval dispenser  10 . As such, increasing the size of the dispensing opening  42  (see  FIG. 1 ) or increasing the maximum height of the oval dispenser are not effective measures for reducing sheet tears as sheet counts are increased in an oval dispenser containing a folded stack  34 . 
     As used herein, the interleaved distance is the contact distance as measured in the width direction of a following sheet that touches one or more panels of a preceding sheet. Referring to  FIG. 3A , the interleaved distance of the sheets  22  in the upper portion  29  is approximately equal to the width of the leading panel  31  or approximately equal to Wu. The interleaved distance of the sheets  22  in the lower portion  30  is approximately equal to the width of the leading panel  31  or approximately equal to W 1 . As such, the interleaved distance varies from the upper portion  29  to the lower portion  30 . In particular, the interleaved distance for the upper portion  29  is less than the interleaved distance for the lower portion  30 . It is believed improved dispensing can occur by reducing the interleaved distance for the upper portion  29 . By having less interleaved distance, it can be easier to remove a sheet from upper portion  29  when the folded stack  34  is placed into the oval dispenser  10 . With too much interleaved distance, the compressive forces from the sidewall  16  acting on the folded stack  34  can cause the sheet to tear during removal from the dispenser. The total frictional force generated by the interleaved contact can exceed the tear strength of the sheet. By reducing the interleaved distance, sheet tears can be reduced while maintaining acceptable pop-up dispensing of the sheets  22  in the upper portion  29 . 
     In various embodiments, the upper portion  29  comprises at least 6 folded sheets, preferably 8 folded sheets or more, or more preferably 10 folded sheets or more. If the number of folded sheets in the upper portion  29  becomes too great, the thickness of the folded stack  34  can become too large, increasing the compression on the folded stack  34  by the sidewall  16  of the oval dispenser  10  in the center portion of the oval dispenser. Therefore, the upper portion  29  comprises about 30 folded sheets or less, or about 20 folded sheets or less. The upper portion  29  can comprise any range of the stated number of sheets such as from about 6 to about 30, or about 8 to about 20 folded sheets. Alternatively, for an oval shaped dispenser, the number of the individual folded sheets in the upper portion  29  divided by the total number of individual folded sheets in the flat stack  20  (upper portion  29 +lower portion  30 ), expressed as a percentage, can be between about 0.5 percent to about 25 percent, or between about 0.5 percent to about 20 percent, or between about 0.5 percent to about 15 percent for the upper portion  29 . 
     For an oval dispenser  10  having a maximum width, Wd, of approximately 3 and ⅞ inches and a maximum length, Ld, of 5 and ⅞ inches, the ratio of the number of the individual folded sheets in the upper portion  29  compared to the number of individual folded sheets in the lower portion  30  can be calculated based on compressing each portion of the folded stack  34  to the same extent by the sidewall  16  of the dispenser  10 . In one embodiment, the sheets in the upper portion  29  are folded into three panels and the sheets in the lower portion  30  are folded into two panels. If the unfolded sheet width is approximately 8.4 inches, the edges  39  where the lower portion  30  touches the sidewall  16  is approximately 1.27 inches above the carton longitudinal axis  18 . The edges  39 , where the upper portion  29  touches the sidewall  16 , are approximately 1.65 inches above the carton longitudinal axis  18 , or approximately 0.37 inches above the edges  39  of the lower portion  30 . When the number of sheets in the lower portion  30  is represented by n 1  and the number of sheets in the upper portion  29  is represented by n 2 , then, for equivalent compression at all edges  39  by the sidewall  16 , 2n 1 =1.27 and 3n 2 =0.37. Solving for the ratio of the number of sheets in the upper portion to the number of sheets in the lower portion, n 2 /n 1 =approximately 0.19. Therefore, if 70 sheets were desired in the lower portion  30 , the number of sheets in the upper portion  29  to have approximately the same sidewall compression for each portion would be 70 multiplied by 0.19 or approximately 13 sheets. 
     Referring now to  FIGS. 4 ,  4 A, and  4 B, a flat stack  20  of a plurality of individual folded sheets  22  of a sheet material  24  having substantially the same unfolded sheet width is illustrated. The flat stack  20  has a substantially uniform maximum length, Ls, measured along a stack longitudinal axis  26 , and a variable width, W, measured in the direction of a stack transverse fold axis  28 . In particular, an upper portion  29  of the flat stack  20  is offset a distance of O from the lower portion  30  of the flat stack. As such, the width of the flat stack  20 , where the upper portion  29  contacts the lower portion  30 , is wider than the width of the upper portion, Wu. In this embodiment, the width, Wu, of the upper portion is substantially the same as the width, Wl, of the lower portion  30  of the flat stack. The maximum width of the flat stack  20  is approximately equal to Wu+O. Equalizing the widths between Wu and Wl can be done by folding the sheets  22  along the longitudinal axis in the upper portion  29  with the same number of folds as the sheets in the lower portion  30 . For example, the sheets  22  in both the upper portion  29  and lower portion  30  could be W-folded, Z-folded, or V-folded. In other embodiments, the width of the upper portion  29  and lower portion  30  can be different. For example, the upper portion  29  can be V-folded and the lower portion  30  J-folded such that Wl is greater than Wu. 
     In one embodiment, as best seen in  FIG. 4A , the flat stack  20  contains individual tissue paper sheets  22  that are folded and interleaved for pop-up dispensing where withdrawing one sheet from the dispenser pulls at least a portion of the next sheet out of the dispenser for easier access to the next sheet. The upper portion  29  of the flat stack  20  includes a plurality of V-folded sheets having a leading panel  31  and a trailing panel  33  separated by a fold line  41 . The leading panel  31  and trailing panel  33  are approximately equal in width. The V-folded sheets are interleaved, with the leading panel  31  of a subsequent sheet placed between the leading panel  31  and trailing panel  33  of a preceding sheet. 
     The lower portion  30  of the flat stack  20  includes a plurality of V-folded sheets having a leading panel  31  and a trailing panel  33  separated by a fold line  41 . The leading panel  31  and trailing panel  33  are approximately equal in width. The V-folded sheets are interleaved, with the leading panel  31  of a subsequent sheet placed between the leading panel  31  and trailing panel  33  of a preceding sheet. At the interface between the upper portion  29  and the lower portion  30 , the transition sheet  40  is J-folded with a shorter leading panel  31  and a longer trailing panel  33  to smoothly transition the offset distance O from the upper portion  29  to the lower portion  30 . Desirably, the leading panel  31  is shortened by O/2 and the trailing panel  33  is lengthened by O/2. In this manner, the maximum surface area of the transition sheet  40  is in contact with both the upper portion  29  and the lower portion  30 . 
     Referring to  FIGS. 3B ,  4 B, and  2 , after assembling the flat stack  20  of interfolded sheets  22 , the flat stack is folded approximately 180 degrees about the stack transverse fold axis  28  adjacent the lower portion  30  to form a folded stack  34  having an arched stack top  36  and a stack bottom  37  comprising two opposing legs  38  located on opposite sides of the transverse fold axis  28  and extending there from. The folded stack  34  is then inserted into the oval dispenser  10  such that the transverse fold axis  28  is substantially parallel to the dispenser longitudinal axis  18  with the stack bottom  37  adjacent the dispenser bottom  14 . In this embodiment, the upper portion  29  would be offset from the lower portion  30  instead of being reduced in width as shown in  FIG. 3B . 
     As seen in  FIG. 4B , this results in the folded stack  34  substantially filling out the length and width of the oval dispenser  10  without the folded stack  34  being unduly compressed by the oval dispenser&#39;s sidewall  16 . Since the upper portion  29  and lower portion  30  of the folded stack  34  are offset, the folded stack  34  fills out the length of the oval dispenser  10 , reducing wasted space at the opposing end portions of the oval dispenser. As a result of the offset distance, O, the thickness of the folded stack  34  is reduced near the smaller radius end portions of the oval dispenser  10 , reducing the sidewall compression on the folded stack. The sidewall compression is particularly reduced while dispensing the initial sheets from the upper portion  29  since the edges  39  of the folded stack  34  having the fold lines  41  are compressed less. The upper portion  29  is offset such that at edges  39 A, where both the upper and lower portions ( 29 ,  30 ) of the folded stack  34  are present, the edges  39 A of the upper portion  29  are located closer towards the center portion of the oval dispenser where the dispenser&#39;s width is wider, reducing compression from the sidewall  16 . At the edges  39 B, where only the upper portion  29  is present, the sidewall compression is reduced even though the dispenser&#39;s width is smaller since the upper portion  29  can compress inwards into the void left in the middle of the folded stack  34  by the absence of the lower portion  30  that has been offset towards the other end of the dispenser. At the edges  39 C, where only the lower portion  30  of the folded stack  34  is present, the overall thickness of the folded stack is significantly less since the upper portion  29  is not present, thereby reducing compression of the stack by the sidewall  16  even though the oval dispenser&#39;s width is smaller at this location. As such, improved dispensing occurs because the initial sheets in the folded stack  34  are compressed less by the sidewall  16 . 
     For an oval shaped dispenser  10 , the number of sheets in the upper portion  29  can be approximately equal to the number of sheets in the lower portion  30 . In other embodiments, the upper portion  29  can contain either more sheets or fewer sheets than the lower portion  30 . For example, the upper portion can contain from about 20 percent to about 80 percent of the total sheets in the flat stack  20 . Alternatively, the upper portion  29  can contain from about 40 percent to about 60 percent of the total sheets in the flat stack  20 , or the upper portion  29  can contain about 50 percent of the total sheets in the flat stack. If the oval dispenser  10  has a maximum length of approximately 5 and ⅞ inches and the sheets have an unfolded width of approximately 8.4 inches, the offset distance, O, can be approximately 1 inch such that the maximum width of the folded stack  34  is approximately 5.2 inches (8.4/2+1) along the carton&#39;s longitudinal axis  18 . The offset distance, O, can be approximately 10 percent to approximately 60 percent of the width of the upper portion  29 , Wu. Alternatively, the offset distance, O, can be approximately 20 percent to approximately 40 percent of the width of the upper portion  29 , Wu. 
     Referring now to  FIGS. 5 ,  5 A, and  5 B, a flat stack  20  of a plurality of individual folded sheets  22  of a sheet-material  24 , having substantially the same unfolded sheet width, is illustrated. The flat stack  20  has a substantially uniform maximum length, Ls, measured along a stack longitudinal axis  26 , and a variable width, W, measured in the direction of a stack transverse fold axis  28 . In particular, an upper portion  29  of the flat stack  20  has a smaller width, Wu, than a middle portion  43  of the flat stack. The middle portion  43  of the flat stack  20  has a smaller width, Wm, than a lower portion  30  of the flat stack having a width Wl. The difference in widths between Wu, Wm, and Wl can be created by folding the same width sheets  22  along the longitudinal axis such that the width of the sheets in each portion is different. For example, the sheets  22  in the upper portion  29  can be Z-folded, the sheets in the middle portion  43  can be V-folded, and the sheets in the lower portion  30  can be J-folded. 
     In one embodiment, as best seen in  FIG. 5A , the flat stack  20  contained individual tissue paper sheets  22  that are folded and interleaved for pop-up dispensing. During pop-up dispensing, withdrawing one sheet from the dispenser pulls at least a portion of the next sheet out of the dispenser for easier access to the next sheet. In the illustrated embodiment, the upper portion  29  of the flat stack  20  includes a plurality of Z-folded sheets having a leading panel  31 , a center panel  32 , and a trailing panel  33  separated by two fold lines  41 . The leading panel  31 , center panel  32 , and trailing panel  33  are approximately equal in width. The Z-folded sheets are interleaved, with the leading panel  31  of a subsequent sheet placed between the center panel  32  and the trailing panel  33  of a preceding sheet. 
     The middle portion  43  of the flat stack  20  includes a plurality of V-folded sheets having a leading panel  31  and a trailing panel  33  separated by a fold line  41 . The V-folded sheets are interleaved, with the leading panel  31  of a subsequent sheet placed between the leading panel  31  and trailing panel  33  of a preceding sheet. The leading panel  31  and trailing panel  33  are approximately equal in width. At the interface between the upper portion  29  and the middle portion  43 , the transition sheet  40  is Z-folded with a shorter leading panel  31 , and longer center and trailing panels ( 32 ,  33 ) to smoothly transition from the upper Z-fold to the middle V-fold. 
     The lower portion  30  of the flat stack  20  includes a plurality of J-folded sheets having a leading panel  31  and a trailing panel  33  separated by a fold line  41 . The J-folded sheets are interleaved, with the leading panel  31  of a subsequent sheet placed above and in contact with the trailing panel  31  of a preceding sheet. The sheets are J-folded with the leading panel  31  being shorter in width than the trailing panel  33 . At the interface between the middle portion  43  and the lower portion  30 , the transition sheet  40  is J-folded with a shorter leading panel  31 , and a longer trailing panel  33  to smoothly transition from the middle V-fold to the lower J-fold. 
     Referring to  FIGS. 3B ,  5 B, and  2 , after assembling the flat stack  20  of interfolded sheets  22 , the flat stack is folded approximately 180 degrees about the stack transverse fold axis  28 , adjacent the lower portion, to form a folded stack  34  having an arched stack top  36  and a stack bottom  37  comprising two opposing legs  38  located on opposite sides of the transverse fold axis  28  and extending there from. The folded stack  34  is then inserted into the oval dispenser  10  such that the transverse fold axis  28  is substantially parallel to the dispenser longitudinal axis  18  with the stack bottom  37  adjacent the dispenser bottom  14 . In this embodiment, an intermediate width middle portion  43  would be present in the folded stack  34  in addition to the upper portion  29  and lower portion  30  as illustrated in  FIG. 3B . 
     As seen in  FIG. 5B , this results in the folded stack  34  substantially filling out the interior length and width of the oval dispenser  10  without the folded stack  34  being unduly compressed by the oval dispenser&#39;s sidewall  16 . Since the upper portion  29  of the folded stack  34  is narrower in width, it fills in the wider center section of the oval dispenser  10 . The thickness of the folded stack  34  is reduced for the middle portion  43  and lower portion  30  near the narrower end portions of the oblong dispenser  10  thereby reducing compression while dispensing the initial sheets; especially at the edges  39  of the folded stack  34  where the fold lines  41  are located. Sheet-material that would have been excessively compressed at the edges  39  has been relocated to the wider sections of the oval dispenser. As such, improved dispensing occurs because the initial sheets in the folded stack  34  are compressed much less by the sidewall  16  when the same number and equivalent thickness sheets comprise the folded stack as opposed to an entirely V-folded interleaved folded stack. 
     It is believed one of the primary causes of sheet dispensing failures in dispensers containing folded stacks  34  is tearing of the initial sheets upon withdrawing them from the dispenser. Sheet tears are believed to occur by attempting to place too many sheets into the folded stack  34 , thereby increasing its thickness such that it is significantly compressed by the sidewall  16  in order to fit into the oval dispenser. As such, increasing the size of the dispensing opening  42  or increasing the maximum height of the oval dispenser are not effective measures for reducing sheet tears. 
     As used herein, the interleaved distance is the contact distance measured in the width direction of a following sheet that touches one or more panels of a preceding sheet. Referring to  FIG. 5A , the interleaved distance of the sheets  22  in the upper portion  29  is approximately equal to the width of the leading panel  31  or approximately equal to Wu. The interleaved distance of the sheets  22  in the middle portion  43  is approximately equal to the width of the leading panel  31  or approximately equal to Wm. As such, the interleaved distance varies from the upper portion  29  to the middle portion  43 . In particular, the interleaved distance for the upper portion  29  is less than the interleaved distance for the middle portion  43 . It is believed improved dispensing can occur by reducing the interleaved distance for the upper portion  29 . By having less interleaved distance, it can be easier to remove a sheet from upper portion  29  when the folded stack  34  is placed into the dispenser  10 . With too much interleaved distance, the compressive forces from the sidewall  16  acting on the folded stack  34  can cause the sheet to tear during removal from the dispenser. The total frictional force generated by the interleaved contact can exceed the tear strength of the sheet. By reducing the interleaved distance, sheet tears can be reduced while maintaining acceptable pop-up dispensing of the sheets  22  in the upper portion  29 . 
     The optimum number of sheets for the upper, middle, and lower portions ( 29 ,  43 ,  30 ) of the flat stack  20  is related to the shape of the dispenser  10  and the sheet fold used for each portion. In the illustrated embodiment, the lower portion  30  is J-folded that results in a thickness of approximately 1.5 panels per sheet, the middle portion  40  is V-folded that results in a thickness of approximately 2 panels per sheet, and the upper portion is Z-folded that results in a thickness of approximately 3 panels per sheet. For a sheet width of approximately 8.4 inches and an oval dispenser 5 and ⅞ inches long by 3 and ⅞ inches wide, it is believed that the least sidewall compression occurs when the lower portion  30  contains approximately 44 percent of the total sheets, the middle portion  43  contains approximately 44 percent of the total sheets, and the upper portion  29  contains approximately 12 percent of the total sheets. Thus, in various embodiments of the invention, the upper portion  29  can contain from about 5 percent to about 20 percent of the total number of sheets in the flat stack  20 , the middle portion  43  can contain from about 20 percent to about 60 percent of the total number of sheets in the flat stack  20 , and the lower portion  30  can contain from about 20 percent to about 60 percent of the total number of sheets in the flat stack  20 . 
     Referring now to  FIGS. 6 ,  6 A,  6 B, and  6 C, a flat stack  20  of a plurality of individual folded sheets  22  of a sheet-material  24  having substantially the same unfolded sheet width is illustrated. The flat stack  20  has a substantially uniform maximum length, Ls, measured along a stack longitudinal axis  26 , and a variable width, W, measured in the direction of a stack transverse fold axis  28 . In particular, an upper portion  29  of the flat stack  20  has a smaller minimum width, Wu, which gradually increases in width than a lower portion  30  of the flat stack. The difference in widths between Wu and W 1  can be created by folding the same width sheets  22  along the longitudinal axis with an interleaved distance that is less than the width of the leading and trailing panels ( 31 ,  33 ) of the V-folded sheets contained in the upper and lower portions ( 29 ,  30 ). 
     In one embodiment, as best seen in  FIG. 6A , the flat stack  20  contains individual tissue paper sheets  22  that are folded and interleaved for pop-up dispensing. During pop-up dispensing, withdrawing one sheet from the dispenser pulls at least a portion of the next sheet out of the dispenser for easier access to the next sheet. The upper and lower portions ( 29 ,  30 ) of the flat stack include a plurality of V-folded sheets having a leading panel  31  and a trailing panel  33  separated by a fold line  41 . The V-folded sheets are interleaved, with the leading panel  31  of a subsequent sheet placed between the leading panel  31  and trailing panel  33  of a preceding sheet. The leading panel  31  and trailing panel  33  are approximately equal in width. 
     The sheets  22  are interleaved such that the interleaved distance is less than the width of the leading and trailing panels ( 31 ,  33 ). In the illustrated embodiment, the interleaved distance is approximately equal to Wu, which is approximately equal to ⅓ of the distance Wl. When the flat stack  20  contains a plurality of sheets  22 , the center  53  of the flat stack, where the sheets are interleaved, becomes taller than the edges. The edges  39  of the flat stack  20  droop and compress since there are less individual tissue layers at the edges of the flat stack than there are individual tissue layers at the center  53  of the flat stack where it is interleaved. As such, the height of the edges  39  of the upper portion  29  of the flat stack  20  is not coincident with the height of the center portion  53 . 
     Referring to  FIGS. 6B and 6C , after assembling the flat stack  20  of interfolded sheets  22 , the flat stack is folded approximately 180 degrees about the stack transverse fold axis  28 , adjacent the lower portion  30  to form a folded stack  34  having an arched stack top  36  and a stack bottom  37  comprising two opposing legs  38  located on opposite sides of the transverse fold axis  28  and extending there from. The folded stack  34  is then inserted into a dispenser  10  having a circular sidewall  16 . This results in the folded stack  34  substantially filling out the cross section of the circular dispenser  10  without the folded stack  34  being unduly compressed by the circular dispenser&#39;s sidewall  16 . 
     Since the upper portion  29  of the folded stack  34  gradually increases in width due to the drooping edges  39 , it helps to fill out more of the circular dispenser&#39;s cross section. Furthermore, since the edges  39  of the folded stack  34  have less individual tissue layers than the center  53 , it is easier for the edges to bend and conform to the circular sidewall  16 . Sheet-material that would have been excessively compressed at the edges  39  has been relocated to the center  53  of the folded stack  34 . As such, improved dispensing occurs because the initial sheets in the folded stack are compressed much less by the sidewall  16 . 
     Referring back to  FIGS. 1 and 2 , the oblong dispenser  10  can further include a dispensing opening  42 , normally located in the top  12 . Alternatively, the dispensing opening  42  can be optionally located partially in the sidewall  16  and in the top  12 , or the dispensing opening can be placed in the bottom  14 . Alternatively, the folded stack  34  can be inverted prior to being placed into the dispenser  10  with the folded stack bottom  14  adjacent to the top  12 . The dispensing opening  42  can optionally include a dispensing window  44 . The dispensing window  44  can be made from a suitable material such as a film, nonwoven, or paper material that can retain a partially dispensed sheet  22 , such as a facial tissue, within the dispensing opening  42  for pop-up dispensing. The dispensing window  44  can have a dispensing orifice  45  that can be a slit; a curvilinear line; a geometric shape such as an oval, a circle, or a triangle; or X-shaped, +-shaped or H-shaped orifice. Alternatively, the dispensing window  44  can be eliminated and fingers or tabs projecting into the dispensing opening  42  can be used to retain a partially dispensed sheet  22 . 
     The dispensing opening  42  can be any size or shape such as square, circular, or oval. The dispensing opening generally will be larger in size for a reach-in dispenser and smaller in size for a pop-up dispenser. The oblong dispenser  10  can further include an optional removable surfboard or cover  46  that can be attached to the dispenser  10  by a perforated or weakened line  47 . The removable cover  46  can be used to prevent foreign materials from entering the filled dispenser and provides protection for the more fragile dispensing window  44  during loading and shipping. The oblong dispenser  10  can also include an optional film wrapper to further cover the dispensing opening  42  or outer portion of the dispenser. The film wrapper can be used to display printed information, such as a prominent trademark, size of the sheets, the number of sheets, or patent information, which can later be removed by the user so as to not detract from the graphic design of the dispenser. 
     The dispenser can be made from suitable materials that include, without limitation, cardboard, carton stock, paper board, polypropylene, polyethylene, polystyrene, ABS plastic, plastic, metal, wood, and glass, amongst other suitable alternatives. 
     In one embodiment, the oblong dispenser  10  included a formed oval sidewall  16  and bottom  14  made from carton stock or paperboard. The bottom  14  can be either recessed or even with the sidewall  16 . The upper end of the sidewall  16  was folded over on the inside of the dispenser  10  to form an edge or lip. The dispenser  10  included a snap-in top  12 , having an outer ring  48  formed from a plastic material that is molded around a paperboard center portion  54  containing the dispensing opening  42 , optional clear poly film dispensing window  44 , and optional removable cover  46 . A flange on the outer ring  48  engages with the edge or lip on the interior of the sidewall  16  to secure the top  12  in place. If desired, the outer ring  48  can include a stacking lip  56  for use with a recessed bottom  14  to nest or interlock vertically stacked dispensers. Suitable snap-in tops and dispensers are disclosed in pending U.S. patent application U.S. 2006/131319 A1 published Jun. 22, 2006 entitled  Container Caps and Containers  by McDonald. 
     Alternative methods of constructing the oblong dispenser  10  can be used. For example, a carton blank or tube can be utilized. The carton blank can comprise a plurality of panels that are folded, assembled, and glued together to form a dispenser. A circular or other cross section shaped tube with plugs or caps can be used to construct the dispenser. Injection molding or thermoforming can be used to form the dispenser. Other techniques known to those of skill in the art can be utilized to make the dispenser  10 . 
     In alternative embodiments of the invention, the flat stack  20  can comprise three, four, or more portions with each portion having a width that increases as you move from the top of the flat stack  20  to the bottom of the flat stack. Alternatively, the width of the folded sheets within the flat stack  20  may be made larger in stepwise increments or increase continuously and gradually from the top to the bottom of the flat stack. 
     Other modifications and variations to the present invention may be practiced by those of ordinary skill in the art, without departing from the spirit and scope of the present invention, which is more particularly set forth in the appended claims. It is understood that aspects of the various embodiments may be interchanged in whole or part. All cited references, patents, or patent applications in the above application for letters patent are herein incorporated by reference in a consistent manner. In the event of inconsistencies or contradictions between the incorporated references and this application, the information present in this application shall prevail. The preceding description, given by way of example in order to enable one of ordinary skill in the art to practice the claimed invention, is not to be construed as limiting the scope of the invention, which is defined by the claims and all equivalents thereto.