JP7700892B2 - Toilet roll - Google Patents

Description

The present invention relates to a toilet roll in which toilet paper is wound into a roll.

In recent years, efforts have been made to reduce the space required for carrying and storing toilet rolls by increasing the length of the toilet paper wound around the toilet roll (hereinafter also referred to as the toilet roll winding length) (Patent Document 1). It is also known that by reducing the basis weight of the toilet paper, the length of the toilet roll can be increased while maintaining the toilet roll winding diameter within a specified dimension (Patent Document 2). It is also known that by increasing the roll density of the toilet paper, the length of the toilet paper can be increased while maintaining the toilet roll winding diameter within a specified dimension (Patent Document 3).

Patent No. 6712491 JP 2006-87703 A JP 2018-061676 A

However, when attempting to lengthen the length of a toilet roll while maintaining the roll diameter within a specified dimension, the toilet paper ends up being wound tightly into a roll. At this time, the toilet paper is generally subjected to greater pressure in areas that are relatively closer to the center of the roll in the radial direction of the toilet roll (inner winding areas) than in areas that are relatively farther from the center of the roll in the radial direction of the toilet roll (closer to the outer periphery of the roll) (outer winding areas). This causes differences in the paper quality of the toilet paper depending on the radial position within the toilet roll, resulting in a problem of differences in the feel of the toilet paper between the beginning and end of use of the toilet roll.

In addition, when trying to increase the roll length by increasing the roll density, the pressure on the inner roll area of the toilet roll increases, causing a difference in the paper quality of the toilet paper between the inner roll area and the outer roll area, resulting in a difference in the texture of the toilet paper between the beginning and end of use of the toilet roll.

Therefore, the present invention aims to provide a toilet roll in which the difference in texture between the beginning and end of use is suppressed, even for toilet rolls with a long roll length.

After extensive research, the inventors discovered that by adjusting the winding density of the toilet roll according to its position within the toilet roll so that the pressure applied to the toilet paper wound onto the toilet roll is smaller in the inner winding region toward the center of the roll than in the outer winding region on the outer periphery of the toilet roll, it is possible to reduce the pressure applied to the inner winding region and suppress the difference in texture between the beginning and end of use of the toilet roll.

Specifically, the present invention has the following configuration.
[1] A toilet roll in which a single ply of toilet paper is wound around a paper core in a roll shape, the roll length is 90 m or more, and the outer winding density ODE of the toilet roll calculated for the outer winding region of the toilet roll corresponding to the region of the toilet paper whose length from the end of the toilet roll center side is in the range of 85% to 95% of the winding length is higher than the inner winding density IDE of the toilet roll calculated for the inner winding region of the toilet roll corresponding to the region of the toilet paper whose length from the end of the toilet roll center side is in the range of 5% to 15% of the winding length.
[2] The toilet roll according to [1], characterized in that the outer winding density ODE ₉₀ , calculated as the winding density of the roll-shaped portion where toilet paper is wound from the end of the toilet roll on the center side of the roll to 90% of the winding length, is more than 1.00 times and not more than 1.50 times the inner winding density IDE ₁₀ , calculated as the winding density of the roll-shaped portion where toilet paper is wound from the end of the toilet roll on the center side of the roll to 10% of the winding length.
[3] The toilet roll according to [1] or [2], characterized in that the outer winding density ODE is 1.15 m/ ^cm2 or more and 1.55 m/ ^cm2 or ^less , and the inner winding density IDE is 0.80 m/ ^cm2 or more and 1.20 m/cm2 or less.
[4] The toilet roll according to any one of [1] to [3], characterized in that the toilet paper is embossed, and an embossing depth of the outer rolled region measured for the outer rolled region is smaller than an embossing depth of the inner rolled region measured for the inner rolled region, the embossing depth of the outer rolled region being 80 μm or more and 115 μm or less, and the embossing depth of the inner rolled region being 85 μm or more and 145 μm or less.
[5] A toilet roll in which toilet paper having a number of plies p (p is an integer of 2 or more) is wound around a paper tube into a roll shape,
The number of plies p and the winding length L (m) satisfy the relationship L≧90/p,
The toilet roll is characterized in that an outer winding density ODE of the toilet roll calculated for an outer winding region of the toilet roll corresponding to a region of the toilet paper whose length from the end of the toilet roll center side is in the range of 85% to 95% of the winding length L is higher than an inner winding density IDE of the toilet roll calculated for an inner winding region of the toilet roll corresponding to a region of the toilet paper whose length from the end of the toilet roll center side is in the range of 5% to 15% of the winding length L.
[6] The toilet roll according to [5], characterized in that the outer winding density ODE ₉₀ , calculated as the winding density of the roll-shaped portion where toilet paper is wound from the end of the toilet roll on the roll center side to a length that is 90% of the winding length L, is more than 1.00 times and not more than 1.50 times the inner winding density IDE ₁₀ , calculated as the winding density of the roll-shaped portion where toilet paper is wound from the end of the toilet roll on the roll center side to a length that is 10% of the winding length L.
[7] The toilet roll according to [5] or [6], characterized in that the outer winding density ODE is 1.10 m/ ^cm2 or more and 1.75 m/ ^cm2 or ^less , and the inner winding density IDE is 0.90 m/ ^cm2 or more and 1.40 m/cm2 or less.
[8] The toilet roll according to any one of [5] to [7], characterized in that the toilet paper is embossed.
[9] The toilet roll according to [8], wherein the embossing is a single embossing.

According to the present invention, it is possible to provide a toilet roll in which the difference in the texture of the toilet paper between the beginning and end of use is suppressed. According to the present invention, even if the roll diameter of a toilet roll with a long roll length is compactly stored within a specified dimension, it is possible to reduce the change in the texture of the toilet paper from the beginning to the end of use of the toilet roll. Therefore, according to the present invention, it is possible to provide a toilet roll with a long roll length, which has a roll diameter within a specified dimension that can be freely rotated and stored in a general toilet roll holder, and in which the change in the texture of the toilet paper is small from the beginning to the end of use. Furthermore, according to the present invention, it is possible to save space when carrying and storing the toilet roll.

FIG. 2 is a diagram illustrating the configuration of a toilet roll according to an embodiment of the present invention. FIG. 2 is a diagram illustrating the configuration of a toilet roll according to an embodiment of the present invention. FIG. 1 is a diagram showing an example of a manufacturing device applicable to the manufacture of a toilet roll according to an embodiment of the present invention. FIG. 4 is a diagram for explaining a method for measuring an embossing depth.

The toilet roll according to the embodiment of the present invention will be described below with reference to the drawings. In the drawings, the same reference numerals indicate the same or similar configurations. The following embodiment and drawings are described for illustrative purposes and are not intended to limit the present invention.

The first to fourth embodiments of the present invention described below relate to single-ply toilet rolls in which so-called single-ply toilet paper formed from one sheet is wound up. The fifth to ninth embodiments relate to multi-ply toilet rolls in which so-called multi-ply toilet paper formed from two or more sheets is wound up.

(First embodiment)
[Toilet roll]
FIG. 1 is a schematic perspective view for explaining the configuration of a toilet roll according to a first embodiment of the present invention.

Referring to FIG. 1, the toilet roll 10 according to the first embodiment of the present invention is a single-ply toilet roll in which a so-called single-ply toilet paper 13 consisting of a single sheet 11 is wound into a roll by a predetermined length L around a paper tube 14, which is a cylindrical core.

[Sheet]
The sheet 11, which is a component of the toilet paper 13, is obtained by papermaking a slurry containing a pulp component, which is a fiber raw material.

[Pulp component]
Pulp components include wood pulp, non-wood pulp, and waste paper pulp.

Examples of wood pulp produced using wood as a raw material include chemical pulps such as hardwood pulp (hardwood kraft pulp (LKP)), softwood pulp (softwood kraft pulp (NKP)), sulfite pulp (SP), dissolving pulp (DP), soda pulp (AP), unbleached kraft pulp (UKP), and oxygen bleached kraft pulp (OKP). Other examples include semi-chemical pulps such as semi-chemical pulp (SCP) and chemi-ground wood pulp (CGP), groundwood pulp (GP), and mechanical pulps such as thermomechanical pulp (TMP, BCTMP), but are not limited thereto.

Non-wood pulps produced from plants or animals other than wood include, but are not limited to, cotton pulps such as cotton linters and cotton lint, non-wood pulps such as hemp, wheat straw, and bagasse, and cellulose, chitin, and chitosan isolated from sea squirts and seaweed.

Recycled paper pulp is pulp produced using recycled paper, i.e. pulp that has been made into paper. Examples of recycled paper pulp include, but are not limited to, so-called milk carton pulp, which is made from paper cartons for filling and packaging liquids, such as milk cartons, and deinked pulp, which is made from newspapers, magazines, etc.

The pulp components may be one of the above, or two or more may be mixed together. These pulp components have a significant effect on the quality of the toilet paper 13, so they are appropriately mixed in a predetermined type and ratio according to the required quality. For example, only wood pulp (100% by mass) can be used as the pulp component.

As the wood pulp, at least one selected from coniferous pulp and hardwood pulp can be preferably used. Coniferous pulp has long and strong fibers, and can impart strength to the sheet produced. Hardwood pulp has short and flexible fibers, and can provide uniformity, good texture, softness, and the like to the sheet produced. In an embodiment of the present invention, it is preferable to use a combination of coniferous pulp and hardwood pulp, and it is more preferable to use a combination of coniferous kraft pulp (NKP) and hardwood kraft pulp (LKP).

When softwood pulp and hardwood pulp are used in combination, the L/N ratio, which indicates the blending ratio (mass ratio) of softwood pulp to hardwood pulp, is, for example, preferably 10/90 to 90/10, more preferably 20/80 or more, even more preferably 30/70 or more, even more preferably 60/40 or more, more preferably 80/20 or less, and even more preferably 70/30 or less.

[Optional ingredients]
Various chemicals may be added to the sheet 11 as optional components in order to achieve the required quality and stabilize the operation. Examples of optional components include dry strength agents, wet strength agents, softeners, bulking agents, dyes, fragrances, dispersants, drainage improvers, pitch control agents, retention improvers, sizing agents, and the like. Examples of dry strength agents include cationic starch, polyacrylamide (PAM), carboxymethyl cellulose (CMC), and the like. Examples of wet strength agents include polyamide epichlorohydrin, urea, melamine, thermally crosslinked polyacrylamide, and the like. Examples of softeners include anionic surfactants, nonionic surfactants, cationic surfactants, and zwitterionic surfactants, and the like. The above optional components may be used alone or in combination of two or more types.

[toilet paper]
In the first embodiment of the present invention, the toilet paper 13 is a single-ply toilet paper, and is composed of one sheet 11. In this specification, the toilet paper 13 and the sheet 11 can be interpreted as synonymous. The toilet paper 13 may be embossed for the purpose of improving the feel such as softness and aesthetics, and may also have perforations for easy separation.

[Basis weight of toilet paper/Basis weight of sheet]
The basis weight of the toilet paper 13 is the basis weight of one sheet 11 constituting the single ply of toilet paper 13. The basis weight of the toilet paper 13 can be obtained by measuring the basis weight of the sheet 11 in accordance with the provisions of Japanese Industrial Standards JIS P8124.

In an embodiment of the present invention, the basis weight of the toilet paper 13 is preferably 13.0 g/m ² or more and 21.0 g/m ² or less, and more preferably 14.0 g/m ² or more and 19.0 g/m ² or less.

If the basis weight is lower than 13.0 g/ ^m2 , the feeling of use will generally be poor due to a decrease in the amount of pulp contained, resulting in a decrease in water absorption, and the strength of the toilet paper 13 will be reduced, making it more susceptible to unintended breakage.

When the basis weight is higher than 21.0 g/m ² , the thickness of the toilet paper 13 generally becomes thicker, and it may become difficult to maintain the winding diameter of the toilet roll 10 at a predetermined dimension.

When the basis weight of the toilet paper 13 is within the range of 13.0 g/ ^m2 or more and 21.0 g/ ^m2 or less, the strength, water absorption, and usability of the toilet paper 13 are ensured, while the roll diameter DR of the toilet roll 10 can be easily maintained at a specified dimension.

In this example, one end of the toilet paper 13 is adhered and fixed to the outer periphery of the paper tube 14 with a pick-up glue (adhesive). This prevents the toilet paper 13 from peeling off and becoming detached from the paper tube 14.

[Paper tube]
The cardboard tube 14 has a cylindrical shape, around which the toilet paper 13 is wound to form the toilet roll 10. The core diameter DC, which is the outer diameter of the cardboard tube 14, is set according to the size of the members (core, hooks, etc.) of the toilet roll holder that support the rotation of the toilet roll 10. The core diameter is preferably 37 mm or more and 42 mm or less, more preferably 38 mm or more and 41 mm or less.

[Toilet roll diameter]
Referring to FIG. 1 , the roll diameter of the toilet roll 10 refers to the roll diameter (diameter) of the toilet paper 13 wound in a roll shape on the toilet roll 10.

In an embodiment of the present invention, the roll diameter DR of the toilet roll 10 as a product specification, i.e., before the start of use, is set to a size that can fit within a typical toilet roll holder and be supported rotatably therein. The roll diameter DR of the toilet roll 10 is preferably 105 mm or more and 130 mm or less, more preferably 110 mm or more and 125 mm or less, and even more preferably greater than 110 mm and less than 125 mm.

If the reel diameter DR of the toilet roll 10 is less than 105 mm, the reel length of the toilet roll 10 may be limited. Also, if an attempt is made to ensure a long reel length of the toilet roll 10 with a reel diameter of less than 105 mm, the paper thickness and basis weight of the toilet paper 13 used in the toilet roll 10 are limited, making it difficult to ensure strength. Alternatively, if the toilet paper 13 is wound too tightly, pressure is applied to the toilet paper 13, deteriorating its texture and usability, and if an embossed surface is provided, the embossed surface may be crushed, deteriorating the cosmetic quality of the toilet roll 10.

The roll diameter can be measured, for example, using a vernier caliper. Since the shape of a toilet roll is not necessarily a perfect circle, the roll diameter can be measured at multiple points around the circumference of the roll and the roll diameter can be calculated as the average value.

[Toilet roll width]
The width H of the toilet roll 10 refers to the length of the toilet roll in the width direction (CD) of the toilet paper 13 wound around the toilet roll 10. The width H of the toilet roll 10 is generally equal to the width and length of the toilet paper 13 wound around the toilet roll 10, due to a manufacturing process that includes a step of obtaining a toilet roll of the product width by cutting a wide toilet roll. In an embodiment of the present invention, the width H of the toilet roll 10 is set to a length that can be accommodated within a general toilet roll holder and supported rotatably therein. The width H of the toilet roll 10, i.e., the width of the toilet paper 13, may be, for example, 110 mm to 120 mm, and is often about 114 mm. The width can be measured using, for example, a vernier caliper or a tape measure.

[Toilet roll length]
The winding length of the toilet roll 10 refers to the length of the toilet paper 13 wound into a roll in the toilet roll 10. In an embodiment of the present invention, the winding length L of the toilet roll 10 before the start of use as a product specification is 90 m or more, preferably 90 m or more and 180 m or less, more preferably 100 m or more and 150 m or less, and even more preferably, if the toilet paper 13 is embossed, 110 m or more and 140 m or less, and if the toilet paper 13 is not embossed, 120 m or more and 150 m or less.

If the roll length L of the toilet roll 10 is less than 90 m, the roll length per roll is short, and if the roll diameter DR is within a specified range, the desired effect of saving space when carrying and storing the toilet roll 10 cannot be obtained. In addition, when the toilet roll 10 is used, it is used up quickly, and frequent refilling of the toilet roll 10 is required.

When the roll length L of the toilet roll 10 is 90 m or more, the length of the toilet paper 13 per roll is long, and if the roll diameter DR is kept within a specified dimension, the toilet roll 10 can be transported and stored in a space-saving manner.

If the roll length L of the toilet roll 10 is too long, the roll diameter DR of the toilet roll 10 will generally be large, making it difficult for the toilet roll 10 to fit into a typical toilet roll holder. In this case, if an attempt is made to keep the roll diameter DR of the toilet roll 10 within a specified dimension, the toilet roll 10 will be wound tightly, increasing the pressure on the toilet paper 13 inside the toilet roll 10, which will tend to deteriorate the texture, feel, and aesthetic appeal of the toilet paper.

The roll length L of the toilet roll 10 can be determined, for example, by actual measurement.

[Toilet roll winding density]
In this specification, the winding density DE of the toilet roll 10 refers to the value obtained by multiplying the winding length L of the toilet roll 10 by the number of plies p (in this example, p = 1), and dividing the result by the roll cross-sectional area A of the toilet roll 10. The winding density of the toilet roll is an index that indicates the winding strength of the toilet paper 13 wound into a roll in the toilet roll 10. Generally, the higher the winding density, the tighter the winding, and the lower the winding density, the looser the winding.

In detail, the winding density of the toilet roll 10 is calculated according to the following formula (I):

(Winding density DE (m/cm ² ))=(Winding length L (m)×Number of plies p)÷(Roll cross-sectional area A (cm ² )) (I)

(c) to (e) in FIG. 2 are schematic diagrams showing cross sections of the toilet roll 10 taken along a direction perpendicular to the axial direction of the toilet roll 10.

Referring to FIG. 2(c), the roll cross-sectional area A of the toilet roll 10 with the roll length L is the area occupied by the annular portion (hatched portion in the figure) having the outer diameter OD and inner diameter ID formed by the wound toilet paper 13 in a cross section of the toilet roll 10 taken along a direction perpendicular to the axial direction of the toilet roll 10. The roll cross-sectional area A is equivalent to the area of a circle whose diameter is the outer diameter OD minus the area of a circle whose diameter is the inner diameter ID.

The outer diameter OD of the annular portion corresponds to the winding diameter DR of the toilet roll 10. The inner diameter ID of the annular portion corresponds to the core diameter DC of the paper tube 14. Therefore, the roll cross-sectional area A of the toilet roll 10 can be calculated by the following formula (II).

(Roll cross-sectional area A (cm ² ))={(winding diameter DR (cm)÷2) ² ×3.14-(core diameter DC (cm)÷2) ² ×3.14} ...(II)

For example, if the winding length L of the toilet roll 10 is 120 m, the winding diameter DR is 114 mm, and the core diameter DC of the paper tube 14 is 40 mm, in an embodiment of the present invention, the toilet paper 13 is single-ply and the number of plies p is 1, so from the above formulas (I) and (II), the winding density DE is calculated as (120 m × 1) ÷ {(11.4 cm ÷ 2) ² × 3.14 - (4.0 cm ÷ 2) ² × 3.14}, which is 1.34 m/cm ² .

[Outer winding area of toilet roll]
2(a) and 2(b) are schematic diagrams showing the state before and after unrolling, that is, before and after unrolling the toilet paper 13 from the toilet roll 10 having a roll length L. With reference to Fig. 2(b), the outer winding region OR of the toilet roll is the region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 85% to 95% of the winding length L of the toilet roll 10. With reference to Fig. 2(a), the outer winding region OR forms a cylindrical shape within the toilet roll 10.

[Inner winding area of toilet roll]
With reference to Fig. 2(b), the inner winding region IR of the toilet roll is a region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 5% to 15% of the winding length L of the toilet roll 10. With reference to Fig. 2(a), the inner winding region IR has a cylindrical shape within the toilet roll 10. With reference to Fig. 2(a), the outer winding region OR of the toilet roll 10 is located on the outer periphery side of the roll, farther from the center of the roll in the radial direction of the toilet roll 10, than the inner winding region IR.

[Outer winding density of toilet roll]
The outer winding density ODE of the toilet roll 10 refers to the winding density of the toilet roll 10 calculated with respect to the outer winding region OR of the toilet roll 10.

Figure 2 (d) shows the toilet roll 10 in a state where the toilet paper 13 is unwound from the toilet roll 10 with the winding length L shown in Figure 2 (c) and the winding length OL is set to a length in the range of 0.85L to 0.95L so that the outer winding area OR of the toilet paper 13 appears on the surface of the toilet roll 10. The winding density of the roll-shaped part of the toilet roll 10 where the toilet paper 13 has been wound up to this winding length OL is the outer winding density ODE of the toilet roll 10.

The roll diameter ODR of the toilet roll 10 in this state can be determined by actual measurement. The outer winding density ODE can be determined by the following formulas (I') and (II') by applying the above formulas (I) and (II) mutatis mutandis.

(Outer winding density ODE (m/cm ² ))=(winding length OL (m)×number of plies p)÷(roll cross-sectional area OA (cm ² )) (I')

(Roll cross-sectional area OA (cm ² ))={(winding diameter ODR (cm)÷2) ² ×3.14-(core diameter DC (cm)÷2) ² ×3.14} (II')

In the formula, the number of plies p is 1, and the winding length OL is 0.85L to 0.95L. When the winding length L of the toilet roll 10 shown in FIG. 2(c) is 120m, the winding length OL of the roll-shaped portion of the toilet roll 10 shown in FIG. 2(d) is in the range of 102m to 114m.

[Toilet roll inner winding density]
The inner winding density IDE of the toilet roll 10 refers to the winding density of the toilet roll 10 calculated with respect to the inner winding region IR of the toilet roll 10.

Figure 2 (e) shows the toilet roll 10 in a state where the toilet paper 13 is unwound from the toilet roll 10 with a winding length L, and the winding length IL is set to a length in the range of 0.05L to 0.15L so that the inner winding region IR of the toilet paper 13 appears on the surface of the toilet roll 10. The winding density of the roll-shaped portion of the toilet roll 10 where the toilet paper 13 has been wound up to this winding length IL is the inner winding density IDE of the toilet roll 10.

The roll diameter IDR of the toilet roll 10 in this state can be determined by actual measurement. The inner roll density IDE can be determined by the following formulas (I") and (II"), applying the above formulas (I) and (II).

(Inner winding density IDE (m/cm ² ))=(Winding length IL (m)×Number of plies p)÷(Roll cross-sectional area IA (cm ² )) ...(I'')

(Roll cross-sectional area IA (cm ² ))={(winding diameter IDR (cm)÷2) ² ×3.14-(core diameter DC (cm)÷2) ² ×3.14} (II'')

In the formula, the number of plies p is 1, and the winding length IL is a length of 0.05L to 0.15L. When the winding length L of the toilet roll 10 shown in FIG. 2(c) is 120 m, the winding length IL of the roll-shaped portion of the toilet roll 10 shown in FIG. 2(d) is in the range of 6 m to 18 m.

In the same manner, the winding density of the toilet roll 10 can be calculated for a specific region in the roll radial direction of the toilet roll 10 other than the outer winding region OR and the inner winding region IR of the toilet roll 10. In other words, the winding density of the roll-shaped portion wound around the paper tube 14 by a region of toilet paper 13 of any length shorter than the winding length L of the toilet roll 10 can be calculated by applying formulas (I) and (II) mutatis mutandis.

If the winding density when "any length shorter than the winding length L of the toilet roll 10" expressed as a percentage of the total length of the toilet paper 13, which is the winding length L, is n% (0<n<100), is described as winding density DEn, the outer winding density ODE corresponds to winding density DEn (85≦n≦95), and the inner winding density IDE corresponds to winding density DEn (5≦n≦15).

The toilet roll 10 according to the first embodiment of the present invention is a toilet roll in which a single ply of toilet paper is wound into a roll, and has a winding length of 90 m or more. The toilet roll 10 is characterized in that the outer winding density ODE, which is the winding density of the toilet roll calculated for the outer winding region OR of the toilet roll, which is the region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 85% to 95% of the winding length L of the toilet roll 10, is higher than the inner winding density IDE, which is the winding density of the toilet roll calculated for the inner winding region IR of the toilet roll, which is the region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 5% to 15% of the winding length L of the toilet roll 10.

That is, in this embodiment, the outer winding density ODE corresponding to the winding density DEn (85≦n≦95) is higher than the inner winding density IDE corresponding to the winding density DEn (5≦n≦15).

[Action and Effect]
In conventional toilet rolls, generally, a higher pressure (internal pressure) is applied to an area located relatively closer to the center of the toilet roll 10 in the radial direction than to an area located relatively closer to the outer periphery of the toilet roll 10 in the radial direction of the toilet roll 10. In addition, when high pressure is applied to the toilet paper inside the toilet roll, the paper thickness is reduced due to compression (higher density of the toilet paper), and if embossed, the embossing is crushed, leading to a deterioration in the texture of the toilet paper and the aesthetic appeal of the toilet roll. This phenomenon is noticeable in toilet paper with a long roll length.

In response to such problems with conventional toilet rolls, in the toilet roll 10 according to an embodiment of the present invention, the winding density of the toilet roll is adjusted according to the position in the radial direction of the toilet roll so that the outer winding density ODE calculated for the outer winding region OR located relatively toward the outer periphery of the roll in the radial direction of the toilet roll 10 is higher than the inner winding density IDE calculated for the inner winding region IR located relatively toward the center of the roll in the radial direction of the toilet roll 10.

In other words, in the present invention, the inner winding density IDE is relatively smaller than the outer winding density ODE, which makes it possible to reduce the pressure applied to the toilet paper 13 in the inner winding region IR even in a toilet roll 10 with a long winding length of a single ply. This makes it possible to suppress a reduction in paper thickness due to compression caused by internal pressure (increasing the density of the toilet paper) and crushing of the embossment if an embossment is applied.

Therefore, according to the present invention, it is possible to reduce the difference in the texture of the toilet paper between the beginning and end of use of the toilet roll 10.

In addition, in this embodiment, the winding density may also be adjusted in regions other than the outer winding region OR and the inner winding region IR, such as an intermediate region located between the outer winding region OR and the inner winding region IR (for example, a region of the toilet paper 13 in a range in which the length from the end 13e on the roll center side of the toilet roll 10 is greater than 15% and less than 85% of the winding length L of the toilet roll 10). For example, the winding density may be gradually decreased from the inner winding region IR to the outer winding region OR in the intermediate region. This increases the effect of suppressing the difference in texture in the length direction of the toilet paper, and reduces the change in the texture of the toilet paper from the beginning to the end of use of the toilet roll.

[Manufacturing apparatus and method applicable to the manufacture of toilet rolls according to embodiments of the present invention]
An example of a manufacturing apparatus and a manufacturing method applicable to manufacturing the toilet roll 10 according to the embodiment of the present invention will be described with reference to Fig. 3. Specifically, the toilet roll 10 whose configuration is shown in Fig. 1 and Fig. 2 can be manufactured, for example, as follows.

[Manufacture of raw roll]
First, a raw roll 11R is manufactured to manufacture the sheet 11, which is a component of the toilet paper 13. In detail, a papermaking machine (not shown) is used to make and wind a wide (several times to twenty-odd times the width H of the toilet roll) and long sheet 11L from a papermaking slurry (paper material), to manufacture a single-ply raw roll 11R on which the sheet 11L is wound.

As a papermaking machine, known papermaking machines such as the twin wire former type, cylinder former type, suction pressed former type, and crescent former type can be used.

The papermaking machine may be equipped with a creping section that performs creping. In the creping section, during the raw roll manufacturing process, a creping doctor can give the sheet, as necessary, very fine wavy wrinkles called crepes while the sheet (web) being made is being dried. Creping can give the sheet softness, bulkiness (bulk), absorbency, aesthetics (crepe shape), and a good feel to the touch.

The papermaking machine may also be equipped with a calendar section. In the calendar section, the dried sheet may be subjected to a calendaring process, in which the sheet is sandwiched and pressed from above and below by a pair of calendar rolls, as necessary. This compresses the sheet 11L, adjusting and equalizing the paper thickness, and smoothing the surface. The calendaring section may be provided separately from the papermaking machine, and the calendaring process may be performed in any manufacturing process after the raw roll manufacturing process. The calendaring process may be performed in multiple stages.

[Manufacturing of toilet rolls]
FIG. 3 is a schematic diagram showing an example of a manufacturing apparatus that can be used to manufacture the toilet roll 10 according to an embodiment of the present invention.

[Example of toilet roll manufacturing equipment]
FIG. 3 shows an example of the configuration of a manufacturing device capable of manufacturing the toilet roll 10 using the raw roll 11R.

The original roll 11R is rotatably attached to the original roll stand and is rotated and driven by a sheet payout device (not shown) to pay out the sheet 11L.

The speed at which the sheet 11L is unwound from the original roll 11R is referred to as the sheet unwinding speed Vu. As the sheet unwinding device, any known device that can unwind the sheet 11L from the original roll 11R at a predetermined unwinding speed and can change the unwinding speed steplessly can be used. The sheet unwinding device may adjust the unwinding speed of the sheet 11L, for example, by controlling the rotation speed of a drive unit that can rotate a shaft passed through the core of the original roll 11R. Alternatively, the sheet unwinding device may adjust the unwinding speed of the sheet 11L by controlling the rotation drive speed of a rotary drive belt that abuts against the outer periphery of the original roll 11R and rotates the original roll 11R. The control of the rotation speed and the rotation drive speed for adjusting the unwinding speed can be performed, for example, by changing the supply voltage or the supply current to the drive unit.

The sheet 11L unwound from the original roll 11R is wrapped around a guide roll 30 and guided to the embossing section 21 located downstream of the original roll stand. Downstream of this embossing section 21, a perforation forming section 25 and a winding section 26 are further arranged in this order.

[Embossed section]
The sheet 11L may be embossed. The embossing unit 21 is, in short, a unit that embosses the sheet 11L to emboss substantially the entire surface of the sheet. The embossing refers to a process that forms an embossed convex portion on one surface of the sheet to be embossed and an embossed concave portion formed by the back side of the embossed convex portion on the other surface.

The embossing section 21 includes a roll set consisting of an embossing roll and a backup roll. The backup roll can be displaced by any known means, such as an air cylinder.

The backup roll may be configured to be selectively displaced between a first position in contact with the embossing roll and a second position away from the embossing roll by displacement of the backup roll.

The embossing roll is a roll having an uneven portion on its outer circumferential surface that corresponds to the desired embossing pattern. In this example, the outer circumferential surface of the embossing roll is formed with uneven portions that correspond to the embossing pattern of the toilet paper 13 (sheet 11) shown in FIG. 4(a). At least the uneven portion of the embossing roll is made of metal, and the embossing roll may be a male (convex) steel roll. This embossing roll is rotated by a driving means (not shown).

The backup roll is a driven roll that is used in contact with the embossing roll and has a cylindrical outer shape. The surface portion of the backup roll is made of a hard rubber-like elastic material such as elastically deformable hard synthetic rubber.

Referring to FIG. 3, when embossing is performed, sheet 11L transported from original roll 11R to embossing section 21 is inserted into a paper path that passes between a backup roll and an embossing roll. While sheet 11L is pressed against the embossing roll by the backup roll, it receives the driving force of the embossing roll and is sent to the downstream side of the roll set. This pressing between the backup roll and the embossing roll forms an emboss on sheet 11L.

In addition, when embossing of the sheet 11L is not required, such as when manufacturing a non-embossed toilet roll, the sheet 11L transported from the original roll 11R may be guided downstream without coming into contact with the embossing roll, for example by being guided only to the backup roll.

After passing through the embossing section 21, the sheet 11L is wound around a guide roll 32 located downstream.

[Guide roll/expander roll]
The guide roll 32 guides the sheet 11L sent out from the embossing section 21 to the downstream side. The guide roll 32 may be an expander roll.

An expander roll is a roll used to remove wrinkles and shrinkage that occur in a sheet as it travels. Expander rolls used in the papermaking and coating processes in the field of papermaking technology can be used, and there are no particular limitations on the type of expander roll that can be applied.

Applicable types of expander rolls include, for example, rubber expander rolls in which a rubber cylinder is rotatably attached to the outer circumference of a bow-shaped non-rotating shaft via a spool containing ball bearings, or steel expander rolls that are not covered with a rubber cylinder, expander rolls with a curved overall shape and spiral grooves, and worm rolls with a linear overall shape and spiral grooves symmetrically provided from the center on the surface of the roll that rotates integrally with the rotating shaft.

When the expander roll 32 is a curved roll, the curved roll rotates around a stationary axis, and the widening effect pushes the sheet 11L outward from the center, stretching and removing wrinkles. This is based on the principle that when the sheet 11L flows while in contact with a typical straight roll (a roll whose overall shape is straight and has no grooves, etc.), with a sufficient wrap angle, the sheet 11L advances in a direction perpendicular to the roll axis.

When the expander roll 32 is a roll with an overall linear shape, the sheet 11L that contacts the surface of the roll that rotates integrally with the rotating shaft is pushed out so as to be expanded along a spiral groove that extends symmetrically from the center of the expander roll 32 and is provided on the surface of the expander roll 32. This makes it possible to stretch and remove wrinkles in the sheet 11L.

Referring to FIG. 3, a feeding means F is provided between the embossing section 21 and the perforation forming section 25 downstream of the embossing section 21 to feed the sheet 11L to the perforation forming section 25. The expander roll 32 is provided upstream of the feeding means F, preferably near the upstream side of the feeding means F, to remove wrinkles and shrinkage of the traveling sheet 11L to be fed into the feeding means F. This makes it possible to prevent the occurrence of wrinkles that may occur when the sheet 11L is passed through the feeding means F without passing through the expander roll 32.

The sheet 11L guided by the guide roll or expander roll 32 is fed into the feeding means F arranged downstream.

[Feeding means]
In the embodiment of the present invention, the feeding means F refers to a means configured to be able to feed out a long sheet that has been fed therein by using a driving force.

An example of the feeding means F is a feed roll. The feed roll has a configuration including at least one driving roll (also called a feed roll) that has a structure that prevents slippage between the sheet 11L and the feed roll. The feed roll may be in the form of a roll (also called a pinch roll) that sandwiches the sheet 11L between two rolls and presses against each other with a certain pressure from above and below (both sides of the sheet 11L) to regulate the feeding, or may be in the form of a feed roll and a nip roll in which the nip roll applies pressure to press the sheet 11L against the feed roll and feeds it using the driving force of the feed roll, or may be in any other known form.

The sheet 11L is fed by the feeding means F to the perforation forming section 25 located downstream.

[Perforation forming section]
The sheet 11L may have perforations formed therein.
The perforation forming section 25 is, in short, a unit that performs perforation forming, that is, forms perforations in the sheets that are fed in.

The perforation forming section 25 is configured to be able to form tear perforations that cross the width of the sheet 11L at regular intervals along the longitudinal direction (MD direction) of the sheet 11L. Any known perforation forming means can be used to form the tear perforations.

In this example, the perforation forming means comprises a rotary blade holder 28h that is driven to rotate, to which a comb-tooth cutter 28c is attached, the cutting edge of which is discontinuous and linear along a direction parallel to the axis of rotation of the rotary blade holder, and a fixed blade holder 29h that is held in a fixed state opposite the rotary blade holder 28h, to which a linear cutter 29c is attached, the cutting edge of which is linear and continuous along a direction parallel to the axis of rotation of the rotary blade holder 28h.

The perforation forming means passes the long sheet 11L between the comb-tooth cutter 28c of the rotary blade holder 28h and the linear cutter 29c of the fixed blade holder 29h. This forms tearing perforations along the width of the sheet 11L that correspond to the cutting edge of the comb-tooth cutter 28c, straddling both widthwise edges of the sheet 11L.

More specifically, the sheet 11L passes across the cutting edge of the linear cutter 29c attached to the fixed blade holder 29h, and the comb-tooth cutter 28c of the rotary blade holder 28h rotates at a peripheral speed corresponding to the speed at which the sheet 11L passes. As the comb-tooth cutter 28c passes the linear cutter 29c, perforations are formed in the sheet 11L. The perforations formed by the comb-tooth cutter 28c and the linear cutter 29c extend across both widthwise edges of the sheet 11L, and serve as tearing perforations for separating the sheet 11L along its width.

If perforations are not required, the rotary blade holder 28h can be held in a position and orientation such that the cutting edge of the comb-tooth cutter 28c of the rotary blade holder 28h does not come into contact with the sheet 11L, allowing the sheet 11L to pass without contacting either the cutting edge of the comb-tooth cutter 28c of the rotary blade holder 28h or the cutting edge of the linear cutter 29c.

After passing through the perforation forming section 25, the sheet 11L is sent to the winding section 26 located downstream.

[Winding section]
The winding section 26 winds the leading end of the sheet 11L delivered from the perforation forming section 25 around a long core (paper tube 14L) in the axial direction with an adhesive, winding the sheet 11L by a predetermined length around the paper tube 14L, and then cuts the rear end of the sheet 11L with a cutter roll 33, which is a cutting means, to form a wide toilet roll 10L, i.e., a toilet roll with a large dimension in the CD direction. This wide toilet roll 10L is also called a winding roll.

In detail, the winding section 26 includes a winding roll W, a nip roll N, and a bed roll B. The winding roll W, the nip roll N, and the bed roll B are arranged to surround the paper tube 14L mounted on the manufacturing device to wind up the sheet 11L. The winding roll W, the nip roll N, and the bed roll B can each be rotated and driven by a drive device (not shown) so that the speed can be changed steplessly. The rotational drive speed of each roll can be controlled by changing the supply voltage and supply current to the drive device.

The sheet 11L sent out from the perforation forming section 25 is wound around the winding roll W in the winding section 26, then passed between the nip roll N and the paper tube 14L, and further passed between the bed roll B and the paper tube 14L to be wound around the paper tube 14L. The winding roll W, nip roll N, and bed roll B come into contact with the outer circumference of the sheet 11L wound around the paper tube 14L, and are rotated in the respective rotational directions indicated by the arrows in FIG. 3, whereby the sheet 11L is wound into a roll around the paper tube 14L to form the toilet roll 10L.

The wide toilet roll 10L thus formed, i.e., the winding roll 10L, is then cut by a cutting section (not shown) to a predetermined width H according to the product specifications, etc., to form individual toilet rolls 10.

[Means for achieving the invention]
As described above, the toilet roll 10 according to the embodiment of the present invention is characterized in that the outer winding density ODE calculated for the outer winding region OR located relatively toward the outer periphery of the roll in the radial direction of the toilet roll 10 is higher than the inner winding density IDE calculated for the inner winding region IR located relatively toward the center of the roll in the radial direction of the toilet roll 10. An example of a means for achieving the configuration of the present invention that satisfies such a relationship of winding density according to the position in the radial direction within the toilet roll 10 will be described.

In the manufacturing device of FIG. 3, the winding speed Vw of the sheet 11L by the rotation of the winding roll W of the winding section 26 is controlled to be faster than the feed speed Vu of the sheet 11L from the original roll 11R by the sheet unwinding function, preferably to have a constant speed difference, thereby adjusting the tension of the sheet 11L between the original roll 11R and the winding roll (toilet roll 10L) (also called "draw adjustment"). The draw adjustment is performed to prevent excessive tension from being generated in the sheet 11L or the sheet 11L from sagging during the winding roll formation process from unwinding the sheet 11L from the original roll 11R to winding it up on the winding roll 10L, which can cause problems such as paper breaks or wrinkles.

By appropriately adjusting the rotational speed Vn of the nip roll N located downstream or the rotational speed Vb of the bed roll B with respect to the winding speed Vw of the winding roll W determined in this manner, the winding density of the toilet roll 10 according to the embodiment of the present invention can be achieved.

Specifically, for example, when the relative magnitude relationship of the speeds is "rotation speed Vn of nip roll N>winding speed Vw of winding roll W", the rotation speed of the downstream roll N is higher than the rotation speed (winding speed) of the upstream roll W, so that the sheet 11L is wound while receiving tension between the two rolls, resulting in a high winding density. Therefore, in the winding process of the toilet roll 10L, by controlling the speed so that the speed difference between the rotation speed Vn and the winding speed Vw is larger at the end of the winding (outer winding area OR) of the sheet 11L compared to the start of the winding (inner winding area IR), the winding density can be made higher in the outer winding area OR than in the inner winding area IR. At this time, the rotation speed Vb of the bed roll B located further downstream of the nip roll N is set to "rotation speed Vb of bed roll B ≧ rotation speed Vn of nip roll N", thereby making it possible to obtain a toilet roll 10L in which the occurrence of slackness, winding wrinkles, etc. is suppressed. When the rotation speed Vb of the bed roll B and the rotation speed Vn of the nip roll N are the same, unnecessary tension is prevented from being applied to the sheet 11L.

Similarly, for example, if the relative speed relationship is "rotational speed Vb of bed roll B > winding speed Vw of winding roll W," the rotational speed of downstream roll B is greater than the rotational speed (winding speed) of upstream roll W, so sheet 11L is wound while receiving tension between the two rolls, resulting in a high winding density. Therefore, in the winding process of toilet roll 10L, by controlling the speed so that the speed difference between rotational speed Vb and winding speed Vw is greater at the end of winding (outer winding region OR) of sheet 11L compared to the start of winding (inner winding region IR), the winding density can be made higher in the outer winding region OR than in the inner winding region IR.

At this time, the rotational speed Vn of the nip roll N, which is located downstream of the winding roll W and upstream of the bed roll B, may be set to "rotational speed Vb of bed roll B ≧ rotational speed Vn of nip roll N ≧ winding speed Vw of the winding roll W." In particular, by setting "rotational speed Vb of bed roll B = rotational speed Vn of nip roll N > winding speed Vw of the winding roll W" or "rotational speed Vb of bed roll B > rotational speed Vn of nip roll N = winding speed Vw of the winding roll W," a relatively large tension can be applied to the sheet 11L, and the winding density can be easily increased.

Alternatively, the winding density of the toilet roll 10 according to the embodiment of the present invention can be achieved by appropriately adjusting the feed speed Vf of the feed roll F located upstream of the winding roll W relative to the winding speed Vw of the winding roll W.

Specifically, for example, if the relative speed relationship is "winding speed Vw of winding roll W > feeding speed Vf of feed roll F," the rotation speed (winding speed) of the downstream roll W is greater than the rotation speed (feeding speed) of the upstream roll F, so the sheet 11L is wound around the toilet roll 10L while receiving tension between the two rolls, resulting in a high winding density. Therefore, in the winding process of the toilet roll 10L, the tension is controlled by adjusting the continuous paper feed speed from the feed roll F so that the speed difference between the winding speed Vw and the feeding speed Vf is relatively large at the end of the winding (outer winding area OR) of the sheet 11L compared to the start of the winding (inner winding area IR), thereby making it possible to make the winding density higher in the outer winding area OR than in the inner winding area IR.

The speed adjustment control for making the outer winding density ODE higher than the inner winding density IDE may be performed in a stepwise manner or may be performed continuously. Stepwise speed adjustment control can simplify the control. Continuous speed adjustment control can gradually increase the winding density of the toilet roll 10, thereby reducing not only the difference in texture between the beginning and end of use of the toilet roll, but also the change in the texture of the toilet paper from the beginning to the end of use of the toilet roll.

Second Embodiment
Next, a second embodiment of the present invention will be described. Unless otherwise specified, the configurations applicable to the above-mentioned embodiments are also applicable to this embodiment.

The toilet roll according to the second embodiment is a variation of the first embodiment.

Referring to FIG. 2(b), in this specification, the line at which the length from end 13e on the roll center side of the toilet roll 10 is 90% of the winding length L of the toilet roll 10 is also referred to as the "90% line." Similarly, the line at which the length from end 13e on the roll center side of the toilet roll 10 is 10% of the winding length L of the toilet roll 10 is referred to as the "10% line."

In this specification, the outer winding density ODE calculated as the winding density DEn (n=90) of the roll-shaped portion in which the toilet paper 13 is wound from the end 13e on the roll center side of the toilet roll 10 to 90% of the winding length L (0.90L), i.e., up to the 90% line, is referred to as the "outer winding density ODE ₉₀ ". Also, in this specification, the inner winding density IDE calculated as the winding density DEn (n=10) of the roll-shaped portion in which the toilet paper 13 is wound from the end 13e on the roll center side of the toilet roll 10 to 10% of the winding length L (0.10L), i.e., up to the 10% line, is referred to as the "inner winding density IDE ₁₀ ".

The toilet roll 10 according to the second embodiment has the same configuration as that of the first embodiment, and is further characterized in that the outer winding density ODE ₉₀ is greater than 1.00 times and not more than 1.50 times the inner winding density IDE ₁₀ , preferably 1.05 times or more and 1.45 times or less, and more preferably 1.10 times or more and 1.40 times or less.

The outer winding density ODE ₉₀ can be calculated using the formulas (I') and (II') described in the first embodiment. At this time, the length 0.90L, which is 90% of the winding length L, is used as the winding length OL. In addition, the toilet paper 13 is unwound from the toilet roll 10 of the winding length L, so that the outer winding region OR ₉₀ , which is the region including the 90% line of the outer winding region OR of the toilet paper 13, appears on the surface (outer peripheral surface) of the toilet roll 10, and the unwound toilet paper 13 is cut and removed at the 90% line. The value of the winding diameter actually measured for the toilet roll 10 (see the roll-shaped portion shown in (d) of FIG. 2) is used as the winding diameter ODR. The outer winding density ODE ₉₀ calculated in this way is hereinafter also referred to as the "outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ ".

Similarly, the inner winding density IDE ₁₀ can be calculated using the formulas (I'') and (II'') described in the first embodiment. At this time, a length of 0.10L, which is 10% of the winding length, is used as the winding length IL. In addition, the toilet paper 13 is unwound from the toilet roll 10 having the winding length L, so that the inner winding region IR ₁₀ , which is a region of the inner winding region IR of the toilet paper 13 including the 10% line, appears on the surface (outer peripheral surface) of the toilet roll 10, and the unwound toilet paper 13 is cut and removed at the 10% line, and the actual winding diameter value of the toilet roll 10 (see the roll-shaped portion shown in (e) of FIG. 2) is used as the winding diameter IDR. The inner winding density IDE ₁₀ calculated in this manner will hereinafter also be referred to as the "inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ ".

[Action and Effect]
The toilet roll 10 according to the second embodiment can achieve the following effects in addition to the same effects as those of the toilet roll 10 according to the first embodiment.

That is, in this embodiment, the outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ is greater than 1.00 times and equal to or less than 1.50 times the inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ , preferably equal to or greater than 1.05 times and equal to or less than 1.45 times, and more preferably equal to or greater than 1.10 times and equal to or less than 1.40 times.

In contrast, when the outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ is 1.00 times or less the inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ , the inner winding density IDE ₁₀ is equal to or greater than the outer winding density ODE _90. In this case, the effect of reducing the pressure (internal pressure) received by the inner winding region IR cannot be obtained, and the difference in texture of the toilet paper 13 between the outer winding region OR and the inner winding region IR becomes large.

In addition, when the outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ exceeds 1.50 times the inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ , high pressure (inner pressure) is applied to the outer winding region OR. As a result, the toilet paper 13 in the outer winding region OR is compressed, and the paper thickness is reduced (the toilet paper 13 is densified), and if embossed, the embossing is crushed, making it difficult to obtain a fluffy feel. In addition, because high pressure is applied to the outer winding region OR, the inner winding region IR, which is wound relatively loosely, is easily deformed by the influence.

As in this embodiment, when the outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ is greater than 1.00 and not more than 1.50 times the inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ , it is possible to achieve both the effect of reducing the pressure (internal pressure) in the inner winding region IR and the effect of preventing an excessive increase in pressure in the outer winding region OR. Therefore, the difference in texture of the toilet paper 13 between the outer winding region OR and the inner winding region IR is small, and the difference in texture from the beginning to the end of use of the toilet roll is unlikely to occur.

Third Embodiment
Next, a third embodiment of the present invention will be described. Unless otherwise specified, the configurations applicable to the first and second embodiments are also applicable to this embodiment.

The toilet roll according to the third embodiment is a variation of the first or second embodiment. The toilet roll according to the third embodiment has a similar configuration to the first or second embodiment, and is further characterized in that the outer winding density ODE is 1.15 m/ ^cm2 or more and 1.55 m/cm2 or ^less , and the inner winding density IDE is 0.80 m/ ^cm2 or more and 1.20 m/ ^cm2 or less.

In the third embodiment, the outer winding density ODE, as defined in the first embodiment, refers to the winding density of the toilet roll calculated for the outer winding region OR of the toilet roll, which is the region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 85% to 95% of the winding length L of the toilet roll 10, and corresponds to the winding density DEn (85≦n≦95) when the winding length is 0.85L to 0.95L.

In addition, the inner winding density IDE in the third embodiment, as defined in the first embodiment, refers to the winding density of the toilet roll calculated for the inner winding region IR of the toilet roll, which is the region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 5% to 15% of the winding length L of the toilet roll 10, and corresponds to the winding density DEn (5≦n≦15) when the winding length is 0.05L to 0.15L.

The outer winding density ODE and the inner winding density IDE can be calculated by applying the formulas (I) and (II) described in the above embodiment.
For example, when it is desired to calculate the outer winding density ODE or inner winding density IDE for an outer winding region ORn (85≦n≦95) or an inner winding region IRn (5≦n≦15) including an n% line at a position where the length from the end 13e on the roll center side of the toilet roll 10 is n% of the winding length L of the toilet roll 10, the outer winding density ODE or inner winding density IDE can be calculated by using the length (n/100)L, (85≦n≦95 or 5≦n≦15) as the winding length in formulas (I) and (II), and measuring the winding diameter of the toilet roll in a state where the toilet paper is unwound up to the n% line, cut, and removed, and substituting this value into the formula.

The outer winding density ODE, which is the winding density when the winding length OL is from 0.85L to 0.95L (when 85≦n≦95), is preferably from 1.15 m/ ^cm2 to 1.55 m/ ^cm2 , more preferably from 1.20 m/ ^cm2 to 1.50 m/ ^cm2 , and even more preferably from 1.25 m/ ^cm2 to 1.45 m/ ^cm2 .

The inner winding density IDE, which is the winding density when the winding length IL is from 0.05L to 0.15L (when 5≦n≦15), is lower than the outer winding density ODE and is preferably 0.80 m/ ^cm2 or more and 1.20 m/ ^cm2 or less, more preferably 0.85 m/ ^cm2 or more and 1.15 m/ ^cm2 or less, and even more preferably 0.90 m/cm2 or ^more and 1.10 m/ ^cm2 or less.

[Action and Effect]
The toilet roll 10 according to the third embodiment can achieve the following effects in addition to the same effects as those described in the first or second embodiment.

In the toilet roll 10 according to this embodiment, the winding density is adjusted so that the outer winding density ODE calculated for the outer winding region OR located relatively toward the outer periphery of the roll in the radial direction of the toilet roll 10 is higher than the inner winding density IDE calculated for the inner winding region IR located relatively toward the center of the roll in the radial direction of the toilet roll 10. The inner winding density IDE in the inner winding region IR, which is the inner side, is lower than the outer winding density ODE in the outer winding region OR, which is the outer side.

In this configuration, if the outer winding density ODE is below 1.15 m/cm ² , the inner winding density IDE will also be below 1.15 m/cm ^2. In this case, the toilet paper 13 will be wound relatively loosely into a roll. As a result, the roll diameter DR will be large, and the toilet roll 10 may not fit into a typical toilet holder.

Furthermore, when the outer winding density ODE exceeds 1.55 m/ ^cm2 , the toilet paper 13 is wound relatively tightly into a roll, and the effect of pressure in the paper thickness direction becomes large. As a result, the toilet paper 13 may be crushed and hardened by compression, or if the toilet paper 13 has an embossed surface, the embossed surface may be crushed, resulting in a deterioration in the texture of the toilet paper 13 and the aesthetic appearance of the toilet roll 10.

Furthermore, if the inner winding density IDE is below 0.80 m/ ^cm2 , the toilet paper 13 will be wound loosely on the roll center side where the inner winding region IR is located. Therefore, the part of the toilet paper 13 included in the inner winding region IR may be misaligned in the axial direction of the toilet roll 10 (the length direction of the paper tube 14), causing a problem of protruding beyond the width H of the roll.

Furthermore, when the inner winding density IDE exceeds 1.20 m/ ^cm2 , the outer winding density ODE also exceeds 1.20 m/ ^cm2 . In this case, the influence of the pressure applied in the paper thickness direction of the toilet paper 13 inside the toilet roll 10 becomes large. This may cause the toilet paper 13 to be crushed and hardened, or if the toilet paper 13 is embossed, the embossment may be crushed, resulting in a deterioration in the texture of the toilet paper 13 and the aesthetic appearance of the toilet roll 10.

In this embodiment, the winding densities are adjusted so that the outer winding density ODE is 1.15 m/cm ² or more and 1.55 m/cm ² or less, and the inner winding density IDE is 0.80 m/cm ² or more and 1.20 m/cm ² or less. According to the configuration of this embodiment, although the winding density varies depending on the position within the toilet roll 10, the winding density is well balanced, and it is possible to provide a toilet roll in which the occurrence of the above-mentioned concerns is prevented.

(Fourth embodiment)
Next, a fourth embodiment of the present invention will be described. Unless otherwise specified, the configurations applicable to the first to third embodiments are also applicable to this embodiment.

The fourth embodiment is a variation of the first to third embodiments, and in addition to the same configuration as any one of the first to third embodiments, the fourth embodiment further has the following configurations (1) to (4).
(1) The toilet paper 13 is embossed.
(2) The outer rolled region embossing depth measured for the outer rolled region OR is less than the inner rolled region embossing depth measured for the inner rolled region IR.
(3) The depth of the outer embossing is 80 μm or more and 115 μm or less.
(4) The depth of the inward embossing is 85 μm or more and 145 μm or less.

[Emboss]
FIG. 4(a) is a schematic diagram corresponding to a portion of the developed view of the toilet roll 10 shown in FIG. 2(b), and shows, in one drawing, a schematic view of the vicinity of the outer winding region OR and the inner winding region IR of the toilet paper 13 unwound from the toilet roll 10.

Referring to (a) and (b) of FIG. 4, the toilet paper 13 (sheet 11) according to this embodiment is embossed with an embossed convex portion on one of the two surfaces and an embossed concave portion on the other surface formed by the back side of the embossed convex portion. The embossing can be mainly applied for the purpose of improving qualities such as touch (softness), flexibility, bulkiness, water absorbency, and cosmetic properties. In particular, for the purpose of improving touch and cosmetic properties, the toilet paper 13 is preferably wound around the toilet roll 10 so that the embossed concave portion is located on the outer peripheral surface of the toilet roll 10 and the embossed convex portion is located on the inner peripheral surface of the toilet roll 10. In addition, as an embossing pattern for this purpose, any embossing pattern formed over substantially the entire surface of the sheet 11 in the form of dots, lines, or a combination of these can be applied.

[Emboss depth]
In a fourth embodiment, the outer rolled region embossing depth measured with respect to the outer rolled region OR is configured to be less than the inner rolled region embossing depth measured with respect to the inner rolled region IR.

As described above with reference to (a) and (b) of Figure 2, the "outer winding region OR" is the region of the toilet paper 13 in which, when the toilet paper 13 is unwound from the toilet roll 10 having a winding length L, the length from the end 13e on the roll center side of the toilet roll 10 is in the range of 85% to 95% of the winding length L of the toilet roll 10.

The "outer winding region embossing depth D1 measured with respect to the outer winding region OR" is the depth D of the embossing recess included in the outer winding region OR, measured along the "90% line" (see FIG. 4(a)), which is a line drawn to bisect the outer winding region OR in the length direction of the toilet paper 13 (see FIG. 4(b)). For example, when the winding length L of the toilet roll 10 is 120 m, the 90% line is located at a position 108 m in length from the end 13e of the toilet roll 10 on the roll center side.

Similarly, the "inner roll region IR" is the region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 5% to 15% of the roll length L of the toilet roll 10 when the toilet paper 13 is unwound from the toilet roll 10 having the roll length L, as described above with reference to (a) and (b) of Figures 2.

The "inner roll region embossing depth D2 measured for the inner roll region IR" is the depth D of the embossed recess contained within the inner roll region IR, measured along the "10% line" (see FIG. 4(a)), which is a line drawn to bisect the inner roll region IR in the length direction of the toilet paper 13 (see FIG. 4(b)). For example, when the winding length L of the toilet roll 10 is 120 m, the 10% line is located 12 m from the end 13e of the toilet roll 10 on the roll center side.

[Method of measuring embossing depth]
Referring to FIG. 4, the emboss depth D (D1, D2) is obtained by measuring the height difference of the emboss using a shape measuring laser microscope. The shape measuring laser microscope scans the XY plane in the observation field of view divided into a plurality of pixels with a laser light source, via an objective lens, and detects the reflected light for each pixel with a light receiving element. Then, the objective lens is driven in the height (Z-axis) direction, and the height information and the reflected light amount are detected with the Z-axis position with the highest reflected light amount as the focal point. By repeating the scan in this manner, a light amount super-depth image and a height image (information) that are focused on the whole can be obtained. The laser light source is a pinhole confocal optical system, so the measurement accuracy is high.

As a shape measurement laser microscope, a One Shot 3D Microscope (VR-3200) (manufactured by KEYENCE) can be used. In addition, as software for observing, measuring, and analyzing images from the laser microscope, the product name "VR-H1A" can be used. Measurement conditions are a magnification of 12 times and a field of view area of 24 mm x 18 mm. Note that the measurement magnification and field of view area may be changed as appropriate depending on the size of the embossing desired.

The embossing depth analysis is carried out according to the following procedure.
(1) For the target image, surface shape correction is performed to remove waviness across the entire field of view.
(2) By measuring the line roughness, the roughness profile between two points on either side of the embossment to be measured is measured, and the inclination is corrected.
(3) The embossing depths Z1 and Z2 at the embossing start point X1 and end point X2 are calculated from the data on the position X (μm) in the planar direction of the embossing and the embossing depth Z (μm) (see FIG. 4C).
(4) The average value of the embossing depths Z1 and Z2 is defined as the maximum embossing depth Zmax, and the difference between this and the minimum embossing depth Zmin located between the embossing start point X1 and end point X2 is defined as the embossing depth ΔZ (see FIG. 4(c)).
ΔZ=Zmax - Zmin
(5) The above measurements (1) to (4) are carried out for any 10 embossments on the toilet paper 13, and the average value of ΔZ is defined as the embossment depth D.

In detail, for the "outer roll region embossing depth D1 measured with respect to the outer roll region OR," any 10 embossments are selected from the embossments on the "90% line" (see FIG. 4(a)). If the number of embossments on the 90% line is less than 10, embossments that are close to the 90% line are selected.

Furthermore, for the "inward rolling region embossing depth D2 measured for the inward rolling region IR," any 10 embossings are selected from the embossings on the "10% line" (see FIG. 4(a)). If the number of embossings on the 10% line is less than 10, the embossings closest to the 10% line are selected.

[Action and Effect]
The toilet roll of this embodiment is an embossed product, and is configured such that the outer winding region embossing depth D1 measured for the outer winding region OR is smaller than the inner winding region embossing depth D2 measured for the inner winding region IR. In other words, the inner winding region IR has a larger embossing depth than the outer winding region OR, and the embossing makes it easier to obtain a fluffy feel. Therefore, it is possible to offset the effects of compression due to internal pressure, and to suppress the difference in texture between the inner winding region and the outer winding region.

In this embodiment, the outer winding region embossing depth D1 (measured along the 90% line) is 80 μm or more and 115 μm or less, preferably 85 μm or more and 110 μm or less, and more preferably 90 μm or more and 105 μm or less. In addition, the inner winding region embossing depth D2 (measured along the 10% line) is 85 μm or more and 145 μm or less, preferably 90 μm or more and 140 μm or less, and more preferably 95 μm or more and 135 μm or less. By setting the embossing depth within this range, the desired effect of embossing can be achieved, for example, the effect of improving quality such as touch (softness), flexibility, bulkiness, water absorption, and aesthetics, and it is also possible to prevent the winding diameter from exceeding a predetermined dimension due to the embossing depth becoming too deep.

[Means for achieving the invention]
The embossing depth can be controlled to vary depending on the region in the longitudinal direction of the toilet paper within a single toilet roll by changing the processing conditions during embossing.
With reference to the embossing section 21 of the manufacturing apparatus shown in Fig. 3, the embossing is performed by passing the sheet 11L between an embossing roll having a convex structure constituting an embossed pattern and a backup roll having a hard rubber-like elastic body on its surface, and pressing the embossed pattern into the sheet 11L. By changing the amount of pressing and/or the pressing pressure when pressing the embossed pattern, an embossed shape having an embossing depth in the above range can be formed. By increasing the amount of pressing and/or the pressing pressure, the embossing depth can be deepened.

Fifth Embodiment
Next, a fifth embodiment of the present invention will be described. Unless otherwise specified, the configurations applicable to the above-mentioned embodiments are also applicable to this embodiment.

The toilet roll 10 according to the first embodiment shown in FIG. 1 is a single-ply toilet roll in which a single ply of toilet paper 13 made of one sheet 11 is wound up, whereas the toilet roll 10 according to the fifth embodiment is a multi-ply toilet roll in which multiple plies of toilet paper 13 made of two or more sheets 11 are wound up.

The toilet roll according to the fifth embodiment has the following configurations (1) to (3).
(1) The toilet roll is a toilet roll in which p plies (p is an integer of 2 or more) of toilet paper are wound into a roll.
(2) The number of plies p and the winding length L (m) satisfy the relationship L≧90/p.
(3) The outer winding density ODE of the toilet roll calculated for the outer winding region of the toilet roll, which corresponds to the region of the toilet paper whose length from the end of the toilet roll on the roll center side is in the range of 85% to 95% of the winding length L, is higher than the inner winding density IDE of the toilet roll calculated for the inner winding region of the toilet roll, which corresponds to the region of the toilet paper whose length from the end of the toilet roll on the roll center side is in the range of 5% to 15% of the winding length L.

Regarding configuration (1), in this embodiment, the number of plies p, which is the number of sheets 11 that make up the toilet paper 13, is 2 or more, preferably 2 or more and 4 or less, and more preferably 2.

Regarding configuration (2), the number of plies p and the winding length L (m) satisfy the relationship of the formula L≧90/p, and the winding length L is preferably 45 m or more, more preferably 45 m or more and 90 m or less, and even more preferably 50 m or more and 75 m or less, and if the toilet paper 13 is embossed, it is preferably 60 m or more and 70 m or less, and if it is not embossed, it is preferably 65 m or more and 75 m or less.

In this embodiment of the multi-ply toilet roll 10, if the winding length L of the toilet roll 10 is less than 45 m, the winding length per roll is short, and if the winding diameter DR is within a predetermined range, the desired effect of saving space when carrying and storing the toilet roll 10 cannot be obtained. In addition, when using the toilet roll 10, it will be used up quickly, requiring frequent refilling of the toilet roll 10.

If the roll length L of the toilet roll 10 is too long, the roll diameter DR of the toilet roll 10 will generally be large, making it difficult for the toilet roll 10 to fit into a typical toilet roll holder. In this case, if an attempt is made to keep the roll diameter DR of the toilet roll 10 within a specified dimension, the toilet roll 10 will be wound tightly, increasing the pressure on the toilet paper 13 inside the toilet roll 10, which will tend to deteriorate the texture, feel, and aesthetic appeal of the toilet paper.

Regarding configuration (3), the "outer winding density ODE of the toilet roll" and the "inner winding density IDE of the toilet roll" in this embodiment can be calculated using the same method and formula as described with reference to FIG. 2 in the first embodiment. In other words, the following formula can be used for the calculation.

(Outer winding density ODE (m/cm ² ))=(winding length OL (m)×number of plies p)÷(roll cross-sectional area OA (cm ² )) (I')
(Roll cross-sectional area OA (cm ² ))={(winding diameter ODR (cm)÷2) ² ×3.14-(core diameter DC (cm)÷2) ² ×3.14} ...(II')
(Inner winding density IDE (m/cm ² ))=(Winding length IL (m)×Number of plies p)÷(Roll cross-sectional area IA (cm ² )) ...(I'')
(Roll cross-sectional area IA (cm ² ))={(winding diameter IDR (cm)÷2) ² ×3.14-(core diameter DC (cm)÷2) ² ×3.14} ...(II'')

In the formula, the number of plies p is p≧2 (p is an integer), the winding length OL is 0.85L to 0.95L, and the winding length IL is 0.05L to 0.15L. The winding diameter ODR, winding diameter IDR, and core diameter DC can be measured.

In FIG. 2(b), it is stated that "L≧90", but this defines the winding length for an embodiment in which the number of plies is p=1. In the fifth embodiment in which the number of plies is p≧2 (p is an integer), the winding length is defined by "L≧90/p".

[Roll diameter DR of toilet roll 10]
In this multiple-ply embodiment, the roll diameter DR of the toilet roll 10 is preferably 100 mm or more and 140 mm or less, more preferably 110 mm or more and 135 mm or less, and even more preferably greater than 110 mm and 130 mm or less.

The roll diameter DR of the toilet roll 10 is set to a size that fits within a typical toilet roll holder and can be supported rotatably therein. If the roll diameter DR of the toilet roll 10 is less than 100 mm, the roll length of the toilet roll 10 may be limited to a short length. In addition, if an attempt is made to ensure a long roll length of the toilet roll 10 with a roll diameter of less than 100 mm, the paper thickness and basis weight of the toilet paper 13 used in the toilet roll 10 are limited, making it difficult to ensure strength. Alternatively, if the toilet paper 13 is wound tightly, pressure is applied to the toilet paper 13, deteriorating its texture and usability, and if an embossed surface is provided, the embossed surface may be crushed, resulting in a deterioration in the cosmetic quality of the toilet roll 10.

[Card core diameter]
The core diameter DC, which is the outer diameter of the cardboard tube 14, is the same as in the single-ply embodiment and is set according to the size of the components of the toilet roll holder (such as the core and hooks) that support the rotation of the toilet roll 10, and is preferably 37 mm or more and 42 mm or less, and more preferably 38 mm or more and 41 mm or less.

[Basic weight]
In this embodiment of the multi-ply toilet paper 13, the basis weight of the toilet paper 13 is calculated as the basis weight per one of the multiple sheets 11 that make up the multi-ply toilet paper 13. The basis weight of the toilet paper 13 can be obtained by measuring according to the provisions of Japanese Industrial Standards JIS P8124.

In this embodiment of the multiple plies, the basis weight of the toilet paper 13 is preferably 10.0 g/m ² or more and 18.0 g/m ² or less, and more preferably 11.0 g/m ² or more and 17.0 g/m ² or less, per sheet.

When the basis weight is lower than 10.0 g/ ^m2 per sheet, the feeling of use generally becomes poor due to a decrease in the amount of pulp contained, resulting in a decrease in water absorption, and the strength of the toilet paper 13 is also reduced, making it more susceptible to unintended breakage.

When the basis weight is higher than 18.0 g/m ² per sheet, the thickness of the toilet paper 13 generally increases, and it may become difficult to maintain the winding diameter of the toilet roll 10 at a predetermined dimension.

When the basis weight of the toilet paper 13 is within the range of 10.0 g/ ^m2 or more and 18.0 g/ ^m2 or less per sheet, the strength, water absorption, and usability of the toilet paper 13 are ensured, while the roll diameter DR of the toilet roll 10 can be easily maintained at a specified dimension.

[Action and Effect]
The toilet roll 10 according to the fifth embodiment is a multi-ply product, whereas the toilet roll 10 according to the first embodiment is a single-ply product. The toilet roll 10 according to the fifth embodiment can achieve the following effects.

In the toilet roll 10 according to this embodiment, the winding density of the toilet roll is adjusted according to the position in the radial direction of the toilet roll so that the outer winding density ODE calculated for the outer winding region OR located relatively closer to the outer periphery of the roll in the radial direction of the toilet roll 10 is higher than the inner winding density IDE calculated for the inner winding region IR located relatively closer to the center of the roll in the radial direction of the toilet roll 10.

That is, in this embodiment, the inner winding density IDE is relatively smaller than the outer winding density ODE. This makes it possible to reduce the pressure applied to the toilet paper 13 in the inner winding region IR even if the winding length of the toilet roll 10, which is made up of two or more plies, is increased. This makes it possible to reduce the paper thickness due to compression caused by the internal pressure (increasing the density of the toilet paper) and to prevent the embossing from being crushed if the embossing is applied.

Therefore, according to the present invention, it is possible to reduce the difference in the texture of the toilet paper between the beginning and end of use of the toilet roll 10.

In addition, in this embodiment, the winding density may also be adjusted in regions different from the outer winding region OR and the inner winding region IR, such as an intermediate region located between the outer winding region OR and the inner winding region IR (for example, a region of the toilet paper 13 in a range in which the length from the end 13e on the roll center side of the toilet roll 10 is greater than 15% and less than 85% of the winding length L of the toilet roll 10, see FIG. 2). For example, the winding density may be gradually decreased from the inner winding region IR to the outer winding region OR in the intermediate region. This increases the effect of suppressing the difference in texture in the length direction of the toilet paper, and reduces the change in the texture of the toilet paper from the beginning to the end of use of the toilet roll.

Sixth Embodiment
The toilet roll according to the sixth embodiment is a variation of the fifth embodiment. Unless otherwise specified, configurations applicable to the fifth embodiment are applicable to this embodiment.

The toilet roll 10 according to the sixth embodiment has a similar configuration to that of the fifth embodiment, and furthermore, the "outer winding density ODE ₉₀ calculated as the winding density of the roll-shaped portion in which toilet paper is wound from the end of the toilet roll on the roll center side to 90% of the winding length L" is more than 1.00 times and not more than 1.50 times, preferably 1.05 times or more and 1.45 times or less, and more preferably 1.10 times or more and 1.40 times or less, of the "inner winding density IDE ₁₀ calculated as the winding density of the roll-shaped portion in which toilet paper is wound from the end of the toilet roll on the roll center side to 10% of the winding length L".

The outer winding density ODE ₉₀ can be calculated using the formulas (I') and (II') described in the fifth embodiment. At this time, the length 0.90L, which is 90% of the winding length L, is used as the winding length OL. In addition, the toilet paper 13 is unwound from the toilet roll 10 of the winding length L, so that the outer winding region OR ₉₀ , which is the region including the 90% line of the outer winding region OR of the toilet paper 13, appears on the surface (outer peripheral surface) of the toilet roll 10, and the unwound toilet paper 13 is cut and removed at the 90% line. The value of the winding diameter actually measured for the toilet roll 10 (see the roll-shaped portion shown in (d) of FIG. 2) is used as the winding diameter ODR. The outer winding density ODE ₉₀ calculated in this manner is also referred to as the "outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ ".

Similarly, the inner winding density IDE ₁₀ can be calculated using the formulas (I'') and (II'') described in the first embodiment. At this time, a length of 0.10L, which is 10% of the winding length, is used as the winding length IL. In addition, the toilet paper 13 is unwound from the toilet roll 10 having the winding length L, so that the inner winding region IR ₁₀ , which is a region of the inner winding region IR of the toilet paper 13 including the 10% line, appears on the surface (outer peripheral surface) of the toilet roll 10, and the unwound toilet paper 13 is cut and removed at the 10% line. The value of the actually measured winding diameter of the toilet roll 10 (see the roll-shaped portion shown in (e) of FIG. 2) is used as the winding diameter IDR. The inner winding density IDE ₁₀ calculated in this manner is also referred to as the "inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ ".

[Action and Effect]
The toilet roll 10 according to the sixth embodiment can achieve the following effects in addition to the same effects as those of the toilet roll 10 according to the fifth embodiment.

That is, in this embodiment, the outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ is greater than 1.00 times and equal to or less than 1.50 times the inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ , preferably equal to or greater than 1.05 times and equal to or less than 1.45 times, and more preferably equal to or greater than 1.10 times and equal to or less than 1.40 times.

In contrast, when the outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ is 1.00 times or less the inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ , the inner winding density IDE ₁₀ is equal to or greater than the outer winding density ODE _90. In this case, the effect of reducing the pressure (internal pressure) received by the inner winding region IR cannot be obtained, and the difference in texture of the toilet paper 13 between the outer winding region OR and the inner winding region IR becomes large.

In addition, when the outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ exceeds 1.50 times the inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ , high pressure (inner pressure) is applied to the outer winding region OR. As a result, the toilet paper 13 in the outer winding region OR is compressed, and the paper thickness is reduced (the toilet paper 13 is densified), and if embossed, the embossing is crushed, making it difficult to obtain a fluffy feel. In addition, because high pressure is applied to the outer winding region OR, the inner winding region IR, which is wound relatively loosely, is easily deformed by the influence.

As in this embodiment, when the outer winding density ODE ₉₀ calculated for the outer winding region OR ₉₀ is greater than 1.00 and not more than 1.50 times the inner winding density IDE ₁₀ calculated for the inner winding region IR ₁₀ , it is possible to achieve both the effect of reducing the pressure (internal pressure) in the inner winding region IR and the effect of preventing an excessive increase in pressure in the outer winding region OR. Therefore, the difference in texture of the toilet paper 13 between the outer winding region OR and the inner winding region IR is small, and the difference in texture from the beginning to the end of use of the toilet roll is unlikely to occur.

Seventh Embodiment
The toilet roll according to the seventh embodiment is a variation of the fifth or sixth embodiment. Unless otherwise specified, configurations applicable to the fifth or sixth embodiment are applicable to this embodiment.

The toilet roll according to the seventh embodiment has a similar configuration to the fifth or sixth embodiment, and further has an outer winding density ODE of 1.10 m/ ^cm2 or more and 1.75 m/ ^cm2 or less, and an inner winding density IDE of 0.90 m/ ^cm2 or more and 1.40 m/ ^cm2 or less.

In the seventh embodiment, the outer winding density ODE, as defined in the above embodiment, refers to the winding density of the toilet roll calculated for the outer winding region OR of the toilet roll, which is the region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 85% to 95% of the winding length L of the toilet roll 10, and corresponds to the winding density DEn (85≦n≦95) when the winding length is 0.85L to 0.95L.

In the seventh embodiment, the inner winding density IDE, as defined in the above embodiment, refers to the winding density of the toilet roll calculated for the inner winding region IR of the toilet roll, which is the region of the toilet paper 13 whose length from the end 13e on the roll center side of the toilet roll 10 is in the range of 5% to 15% of the winding length L of the toilet roll 10, and corresponds to the winding density DEn (5≦n≦15) when the winding length is 0.05L to 0.15L.

The outer winding density ODE and the inner winding density IDE can be calculated by applying the formulas (I) and (II) described in the above embodiment.

In detail, the winding density of the toilet roll 10 is calculated according to the following formula (I):

(Winding density DE (m/cm ² ))=(Winding length L (m)×Number of plies p)÷(Roll cross-sectional area A (cm ² )) (I)
(Roll cross-sectional area A (cm ² ))={(winding diameter DR (cm)÷2) ² ×3.14-(core diameter DC (cm)÷2) ² ×3.14} ...(II)
For example, when it is desired to calculate the outer winding density ODE or inner winding density IDE for an outer winding region ORn (85≦n≦95) or an inner winding region IRn (5≦n≦15) including an n% line at a position where the length from the end 13e on the roll center side of the toilet roll 10 is n% of the winding length L of the toilet roll 10, the outer winding density ODE or inner winding density IDE can be calculated by using the length (n/100)L, (85≦n≦95 or 5≦n≦15) as the winding length in formulas (I) and (II), and measuring the winding diameter of the toilet roll in a state where the toilet paper is unwound up to the n% line, cut, and removed, and substituting this value into the formula.

The outer winding density ODE, which is the winding density when the winding length OL is between 0.85L and 0.95L (when 85≦n≦95), is 1.10 m/cm ² or more and 1.75 m/cm ² or less. In addition, when the toilet paper 13 is embossed, the outer winding density ODE is preferably 1.15 m/cm ² or more and 1.60 m/cm ² or less, more preferably 1.20 m/cm ² or more and 1.50 m/cm ² or less, and when the toilet paper 13 is not embossed, it is preferably 1.30 m/cm ² or more and 1.70 m/cm ² or less, more preferably 1.40 m/cm ² or more and 1.65 m/cm ² or less.

The inner winding density IDE, which is the winding density when the winding length IL is 0.05L to 0.15L (when 5≦n≦15), is lower than the outer winding density ODE, and is 0.90 m/cm ² or more and 1.40 m/cm ² or less. In addition, when the toilet paper 13 is embossed, the inner winding density IDE is preferably 0.95 m/cm ² or more and 1.30 m/cm ² or less, more preferably 1.00 m/cm ² or more and 1.20 m/cm ² or less, and when the toilet paper 13 is not embossed, it is preferably 1.00 m/cm ² or more and 1.35 m/cm ² or less, more preferably 1.10 m/cm ² or more and 1.30 m/cm ² or less.

[Action and Effect]
The toilet roll 10 according to the seventh embodiment can achieve the following effects in addition to the same effects as those described in the fifth or sixth embodiment.

In the toilet roll 10 according to this embodiment, the winding density is adjusted so that the outer winding density ODE calculated for the outer winding region OR located relatively toward the outer periphery of the roll in the radial direction of the toilet roll 10 is higher than the inner winding density IDE calculated for the inner winding region IR located relatively toward the center of the roll in the radial direction of the toilet roll 10. The inner winding density IDE in the inner winding region IR, which is the inner side, is lower than the outer winding density ODE in the outer winding region OR, which is the outer side.

In this configuration, if the outer winding density ODE is below 1.10 m/cm ² , the inner winding density IDE will also be below 1.10 m/cm ^2. In this case, the toilet paper 13 will be wound relatively loosely into a roll. As a result, the roll diameter DR will be large, and the toilet roll 10 may not fit into a typical toilet holder.

Furthermore, if the outer winding density ODE exceeds 1.75 m/ ^cm2 , the toilet paper 13 will be wound relatively tightly into a roll, and the effect of pressure in the paper thickness direction will be large. As a result, the toilet paper 13 will be crushed and hardened by compression, and if the toilet paper 13 has an embossed surface, the embossed surface will be crushed, which may result in a deterioration in the texture of the toilet paper 13 and the aesthetic appearance of the toilet roll 10.

Furthermore, if the inner winding density IDE is below 0.90 m/ ^cm2 , the toilet paper 13 will be wound loosely on the roll center side where the inner winding region IR is located. Therefore, the part of the toilet paper 13 included in the inner winding region IR may be misaligned in the axial direction of the toilet roll 10 (the length direction of the paper tube 14), causing a problem of protruding beyond the width H of the roll.

Furthermore, when the inner winding density IDE exceeds 1.40 m/cm ² , the outer winding density ODE also exceeds 1.40 m/cm ^2. In this case, the influence of the pressure applied in the paper thickness direction of the toilet paper 13 inside the toilet roll 10 becomes large. This may cause the toilet paper 13 to be crushed and hardened, or if the toilet paper 13 is embossed, the embossment may be crushed, resulting in a deterioration in the texture of the toilet paper 13 and the aesthetic appearance of the toilet roll 10.

In this embodiment, under the premise that the outer winding density ODE is higher than the inner winding density IDE, the winding densities are adjusted so that the outer winding density ODE is 1.10 m/cm ² or more and 1.75 m/cm ² or less, and the inner winding density IDE is 0.90 m/cm ² or more and 1.40 m/cm ² or less. According to the configuration of this embodiment, although the winding density differs depending on the position in the toilet roll 10, the winding densities are well balanced, and it is possible to provide a toilet roll in which the occurrence of the above-mentioned concerns is prevented.

Eighth embodiment
The toilet roll according to the eighth embodiment is a variation of the fifth, sixth or seventh embodiment. Unless otherwise specified, configurations applicable to the fifth, sixth or seventh embodiment are applicable to this embodiment.

The toilet roll 10 of the eighth embodiment has a configuration similar to that of the fifth, sixth or seventh embodiment, and further includes an embossed surface on the toilet paper 13.

Embossing is generally imparted to the toilet paper 13 for the purpose of improving the feel, such as softness, and cosmetic properties, etc. The embossing can be imparted, for example, by inserting the sheet to be embossed between a pair of rolls in an embossing unit 21 and pressing it using a toilet roll manufacturing device such as that shown in Figure 3.
Since the toilet roll 10 of the present embodiment is a multi-ply, any processing method can be adopted without particular limitation, such as so-called single embossing in which each sheet constituting the multi-ply is laminated and then embossed, or so-called double embossing in which each sheet is embossed and then laminated.

[Action and Effect]
The toilet roll 10 according to the eighth embodiment can achieve the following effects in addition to the same effects as those described in the fifth, sixth or seventh embodiment.

In the toilet roll 10 according to this embodiment, the toilet paper 13 is embossed. According to this embodiment, the embossing partially destroys the aggregate state of the fibers that make up the toilet paper 13, improving the qualities of the toilet paper 13, such as fluffiness, absorbency, and cosmetic properties.

Ninth embodiment
The toilet roll according to the ninth embodiment is a variation of the eighth embodiment. Unless otherwise specified, configurations applicable to the eighth embodiment are applicable to this embodiment.

In the toilet roll 10 of the ninth embodiment, the toilet paper 13 is embossed, and the embossing is single embossed.

Single embossing is a process in which the toilet paper 13 is made by stacking a specified number of sheets 11 together, and then pressing the protrusions of an embossing roll against only one side of the sheet 13 to form an embossment.

[Action and Effect]
In the case of double embossing, in which each sheet 11 is embossed and then the sheets 11 are stacked, if the same embossing height (embossed unevenness) as in single embossing is imparted, the thickness of the toilet paper 13 after stacking may become too thick and exceed the specified roll diameter. Also, if the embossing height imparted to each sheet 11 is lowered to achieve the specified roll diameter, the effect of embossing, such as the effect of improving quality such as softness, water absorbency, and cosmetic properties, will be inferior.

In contrast, with single embossing, the same pattern of embossed unevenness is applied to the entirety of the multiple plies, so the above-mentioned problems do not occur. Therefore, with this embodiment, it is easy to achieve both a specified winding diameter and improved quality effects such as softness, water absorbency, and cosmetic properties.

(Examples 101 to 118)
Through the following manufacturing process, single-ply toilet rolls according to Examples 101 to 118 of the present invention were manufactured.
(a) Using a twin-wire former type papermaking machine (not shown), a wide sheet 11L was made from a papermaking slurry (paper material) having a pulp composition in which the ratio (L/N ratio) of hardwood bleached kraft pulp (LBKP) to softwood bleached kraft pulp (NBKP) was 65% by mass:35% by mass, and a raw roll 11R on which the sheet 11L was wound was obtained.
(b) The original roll 11R was mounted on the sheet feeding function of the manufacturing apparatus shown in FIG. 3, and while the sheet 11L was being pulled out from the original roll 11R, embossing was performed in Examples 101 to 115 to give embossed unevenness, and in Examples 116 to 118, perforations were formed without embossing, and the end of the sheet 11L was pressed against a wide paper tube 14L coated with pick-up glue to adhere and fix it, and the sheet was wound up in a roll around the paper tube 14L.
(c) When the wound length reached a predetermined length, the end of the wound sheet 11L was cut off and the end of the sheet was adhered and fixed to the outer periphery of the roll with a tail seal glue to obtain a wide toilet roll 10L.
(d) The wide toilet roll 10L was cut to a specified width (114 mm) to produce the toilet roll 10 in which a single-ply toilet paper 13 composed of the sheet 11 was wound into a roll.
(Examples 201 to 214)
Through the following manufacturing process, two-ply toilet rolls according to Examples 201 to 214 of the present invention were manufactured.
(a) Using a twin-wire former type papermaking machine (not shown), a wide sheet 11L was made from a papermaking slurry (paper material) having a pulp composition in which the ratio (L/N ratio) of hardwood bleached kraft pulp (LBKP) to softwood bleached kraft pulp (NBKP) was 65% by mass:35% by mass, and a raw roll 11R on which the sheet 11L was wound was obtained.
(b) Two original rolls 11R were mounted on the sheet feeding function of the manufacturing apparatus shown in FIG. 3, and sheets 11L were pulled out from each of the two original rolls 11R. In Examples 201 to 210, after overlapping the sheets 11L, and in Example 211, before overlapping the sheets 11L, embossing was performed in the embossing section 21 to give embossed unevenness, and in Examples 212 to 2114, the sheets 11L were overlapped without embossing, then perforations were formed, and the ends of the sheets 11L were pressed against a wide paper tube 14L to which a pickup glue had been applied, adhesively fixed, and the sheets were wound up in a roll around the paper tube 14L.
(c) When the wound length reached a predetermined length, the end of the wound sheet 11L was cut off and the end of the sheet was adhered and fixed to the outer periphery of the roll with a tail seal glue to obtain a wide toilet roll 10L.
(d) The wide toilet roll 10L was cut to a specified width (114 mm) to produce a toilet roll 10 in which two plies of toilet paper 13 made of two sheets 11 were wound into a roll.

(Comparative Examples 101 to 104 and Comparative Examples 201 to 204)
Single-ply Comparative Examples 101 to 104 shown in Table 4 and two-ply Comparative Examples 201 to 204 shown in Table 7 were manufactured.

(Measurement and Evaluation)
The toilet rolls manufactured in the Examples and Comparative Examples were subjected to the following measurements and evaluations. The measurements were performed by conditioning the samples in an environment conforming to Japanese Industrial Standard JIS P8111 (temperature 23±1°C, humidity 50±2% RH).

<Measurement>
[Toilet roll length [m]]
The toilet paper was unwound from the toilet roll and the length of the toilet paper was measured. Measurements were taken in 0.5 m increments and the fractional parts were rounded down. The length and winding length used to measure the winding density were based on, for example, the product specifications of the toilet roll, and the length of the unwound toilet paper was measured while unwinding the toilet paper from the toilet roll, and the values were used to determine the length of the toilet paper wound around the paper core at that stage in the toilet roll.

[Toilet roll diameter [mm]]
The outer diameter of the toilet roll was measured with a vernier caliper and rounded off to the nearest whole number.

[Core diameter of paper tube [mm]]
The outer diameter of the paper tube of the toilet roll was measured with a vernier caliper and rounded off to the nearest whole number.

[Basic weight [g/m ² ]]
The toilet paper was unwound from the toilet roll, and the basis weight per sheet of the toilet paper was measured according to the provisions of Japanese Industrial Standard JIS P8124.

[Winding density]
The winding density of the toilet paper included in each toilet roll sample was calculated by the following formulas (I) and (II) when the total length (winding length) L of the toilet paper was taken as 100%. In addition, the winding density of the roll-shaped portion in which the toilet paper area having lengths of 90% (0.90L), 75% (0.75L), 50% (0.5), 25% (0.25L), and 10% (0.10L) from the edge of the toilet roll on the center side of the roll was wound around the paper core was calculated by applying the following formulas (I) and (II) mutatis mutandis and using those lengths as the winding length.

(Winding density (m/cm ² ))=(Winding length (m)×Number of plies)÷(Roll cross-sectional area (cm ² )) (I)

(Roll cross-sectional area (cm ² ))={(winding diameter (cm)÷2) ² ×3.14-(core diameter DC (cm)÷2) ² ×3.14} ...(II)

[Embossing depth]
The embossing depth was measured at positions on the toilet paper that were 90% (0.90L) and 10% (0.10L) in length from the edge of the toilet roll on the center side of the roll (i.e., the 90% line and the 10% line) according to the test device, conditions, and analysis method described above.

[HF value]
The HF values were determined for toilet paper areas with lengths of 90% (0.90L), 75% (0.75L), 50% (0.5), 25% (0.25L), and 10% (0.10L) from the edge of the toilet roll on the center side of the roll.

HF value (hand feel value) is a numerical value that can be used to quantitatively evaluate the smoothness, flexibility, volume, and other tactile sensations of sanitary tissue paper. The HF values of the toilet paper in the examples and comparative examples were measured using a tissue softness analyzer (manufactured by Emtec Electronic GmbH). A sample cut into a circle with a diameter of 112.8 mm was placed on a sample stand, and a bladed rotor was pressed into this sample from above with a pressing pressure of 100 mN. The bladed rotor was then rotated so that the rotation speed was 2.0 rpm, and the vibration frequency at that time was measured. In addition, the amount of deformation displacement in the vertical direction was calculated when the bladed rotor was pressed into another sample cut into a circle with a diameter of 112.8 mm with a pressure of 100 mN and 60 mN. The HF value is a value calculated from the vibration frequency and the amount of deformation displacement, and the calculation algorithm used was TP II. The above measurements were performed 10 times on the exposed surface of the toilet paper on the outside of the roll and the exposed surface of the toilet paper on the inside of the roll (i.e., the front and back surfaces of the sheet) of each sample, and abnormal values were removed from the obtained measurement data using the Hampel Identifier method, and the average value was calculated for each surface. Furthermore, the average HF value of both sides was calculated from the average HF value of each surface calculated in this way, and this was used as the HF value for evaluation. The above samples were measured in an environment conforming to ISO187 (temperature 23±1°C, relative humidity 50±2%). In addition, when measuring, calibration was performed using a standard sample (eme tec ref. 2X (nn.n)) according to the attached instructions, and the algorithm was set to TP II. The calculation software used was emtec measurement system Ver. 3.22.

The sample used to measure the HF value was cut from the edge of the toilet paper opposite the edge on the center side of the toilet roll, i.e., the side closer to the edge on the outer periphery, in the area of the toilet paper to be measured. Specifically, for example, when determining the HF value for an area of toilet paper that is 90% (0.90 L) in length from the edge on the center side of the toilet roll, samples were taken from the side of the toilet paper area closest to the 90% line, with as little space between them as possible.

The higher the HF value, the better the texture. The greater the difference in HF value between the outer rolled area (90%) and the inner rolled area (10%), the more the difference in quality is felt. If the difference in HF value between the outer rolled area (90%) and the inner rolled area (10%) exceeds 5.0 points, the difference in quality may be felt during use, and it is rated as undesirable. It is more preferable that the difference in HF value between the outer rolled area (90%) and the inner rolled area (10%) is 4.0 points or less, and even more preferable that it is 3.0 points or less.

The test results are shown in Tables 1 to 7.

(Test results for single-ply products)
First, referring to Tables 1 to 4, the test results for the single-ply examples and comparative examples will be examined.
As shown in Tables 1 to 4, all of Example 101 to Comparative Example 104 were single-ply toilet rolls in which a single-ply of toilet paper was wound into a roll, and the roll diameter was 90 m or more. In addition, the width dimension of each sample was 114 mm, and the core diameter was 38 mm to 41 mm.

Of all the single-ply samples, the toilet papers of Examples 101 to 115 and Comparative Examples 101 to 103 were embossed, but the toilet papers of Examples 116, 117, 118, and Comparative Example 104 were not embossed. Perhaps for this reason, the toilet rolls of Examples 116, 117, 118, and Comparative Example 104 had the longest winding length of all the single-ply samples, at 150 m.

In the toilet rolls of Examples 101 to 118 (all single-ply examples), the outer winding density of the toilet roll calculated for the outer winding region of the toilet roll, which corresponds to the region of the toilet paper whose length from the end of the toilet roll on the center side of the roll is in the range of 85% to 95% of the winding length, was higher than the inner winding density of the toilet roll calculated for the inner winding region of the toilet roll, which corresponds to the region of the toilet paper whose length from the end of the toilet roll on the center side of the roll is in the range of 5% to 15% of the winding length.

In addition, for the toilet rolls of Examples 101 to 118 (all single-ply examples), the outer winding density, calculated as the winding density of the roll-shaped portion in which toilet paper is wound from the end of the toilet roll on the center side of the roll to 90% of the winding length, was more than 1.00 times and not more than 1.50 times the inner winding density, calculated as the winding density of the roll-shaped portion in which toilet paper is wound from the end of the toilet roll on the center side of the roll to 10% of the winding length.

In addition, the toilet rolls of Examples 101 to 114 and Examples 116 to 118 all had an outer winding density of 1.15 m/cm ² or more and 1.55 m/cm ² or less, and an inner winding density of 0.80 m/cm ² or more and 1.20 m/cm ² or less.

In addition, the toilet roll of Example 115 had a basis weight of 19.8 g/ ^m2 , which was higher than the other samples, and accordingly had the shortest winding length of 100 m among all the samples. The inner winding density was in the range of 0.80 m/ ^cm2 or more and 1.20 m/cm2 or ^less , but the outer winding density was 1.12 m/ ^cm2 , which was slightly lower than 1.15 m/ ^cm2 .

Furthermore, the toilet rolls of Examples 101 to 115 are embossed products, and the embossing depth of the outer rolled region (90%) measured for the outer rolled region is smaller than the embossing depth of the inner rolled region measured for the inner rolled region, with the embossing depth of the outer rolled region being 80 μm or more and 115 μm or less, and the embossing depth of the inner rolled region being 85 μm or more and 145 μm or less.

The toilet rolls of Examples 101 to 118 (all single-ply examples) had a small difference in HF value between the outer rolled region (90%) and the inner rolled region (10%), about a few points, less than 5.0 points, which was favorable.

In addition, the HF values of the toilet rolls of Examples 101 to 118 (all single-ply examples) were almost constant even in areas other than the outer roll area (90%) and the inner roll area (10%), and there was little change in texture across the entire area of the toilet paper, regardless of the length of the toilet paper.

In Comparative Example 101, the winding density of the inner winding region (10%) was higher than that of the outer winding region (90%), and the winding density of the outer winding region (90%) was less than 1.0 times the winding density of the inner winding region (10%). In addition, the difference in HF value between the outer winding region (90%) and the inner winding region (10%) was large, exceeding 5.0 points, and there was a difference in the quality of the toilet paper between the beginning and end of the toilet roll.

In Comparative Example 102, the winding density of the inner winding region (10%) was similar to that of the outer winding region (90%). However, there was a large difference in HF value between the outer winding region (90%) and the inner winding region (10%), exceeding 5.0 points, and there was a difference in the quality of the toilet paper between the beginning and end of the toilet roll.

In Comparative Example 103, the winding density of the inner winding region (10%) was higher than that of the outer winding region (90%), and the winding density of the outer winding region (90%) was less than 1.0 times that of the inner winding region (10%). In addition, the winding density (100%) calculated as the winding density of the roll-shaped portion in which toilet paper has been wound up to 100% of the winding length was low, and therefore the winding diameter was very large, exceeding the dimensions that could be accommodated in a typical toilet roll holder and supported rotatably therein. In addition, the difference in HF value between the outer winding region (90%) and the inner winding region (10%) was large, exceeding 5.0 points, and there was a difference in the quality of the toilet paper between the beginning and end of the toilet roll.

In the non-embossed product, Comparative Example 104, the winding density of the inner winding region (10%) was almost the same as that of the outer winding region (90%). In addition, the difference in HF value between the outer winding region (90%) and the inner winding region (10%) was large, exceeding 5.0 points, and there was a difference in the quality of the toilet paper between the beginning and end of the toilet roll.

(Test results for multi-ply items)
Next, referring to Tables 5 to 7, the test results for the multi-ply (2-ply) examples and comparative examples will be discussed.

As shown in Tables 5 to 7, all of Example 201 to Comparative Example 204 were two-ply toilet rolls in which two plies of toilet paper were wound into a roll, and the roll diameter was 100 mm or more and 140 mm or less. In addition, the width dimension of each sample was 114 mm, and the core diameter was 38 mm to 41 mm.

Of all the multi-ply samples, the toilet paper of Examples 201 to 210 and Comparative Examples 201 to 203 were single embossed, the toilet paper of Example 211 was double embossed, and Examples 212 to 214 and Comparative Example 204 were not embossed. The sample without embossing had the longest winding length of all the multi-ply samples, at 75 m.

In the toilet rolls of Examples 201 to 214 (all multi-ply examples), the outer winding density of the toilet roll calculated for the outer winding region of the toilet roll, which corresponds to the region of the toilet paper whose length from the end of the toilet roll on the center side of the roll is in the range of 85% to 95% of the winding length, was higher than the inner winding density of the toilet roll calculated for the inner winding region of the toilet roll, which corresponds to the region of the toilet paper whose length from the end of the toilet roll on the center side of the roll is in the range of 5% to 15% of the winding length.

In addition, for the toilet rolls of Examples 201 to 214 (all multi-ply examples), the outer winding density, calculated as the winding density of the roll-shaped portion in which toilet paper is wound from the end of the toilet roll on the center side of the roll to 90% of the winding length, was more than 1.00 times and not more than 1.50 times the inner winding density, calculated as the winding density of the roll-shaped portion in which toilet paper is wound from the end of the toilet roll on the center side of the roll to 10% of the winding length.

In addition, the toilet rolls of Examples 201 to 214 (all multi-ply examples) all had an outer winding density of 1.10 m/cm ² or more and 1.75 m/cm ² or less, and an inner winding density of 0.90 m/cm ² or more and 1.40 m/cm ² or less.

The toilet rolls of Examples 201 to 211, which are embossed products, had higher HF values and better textures than the non-embossed products of Examples 212 to 214. Similarly, the toilet rolls of Comparative Examples 201 to 203, which are embossed products, had higher HF values and better textures than the non-embossed product of Comparative Example 204.

Furthermore, while the toilet rolls of Examples 201 to 211 and the toilet rolls of Comparative Examples 201 to 203 were both embossed products, the difference in HF value between the outer rolled region (90%) and the inner rolled region (10%) of the toilet rolls of Examples 201 to 211 was small, ranging from a few points to less than 5.0 points, which was favorable.

In addition, the HF values of the toilet rolls of Examples 201 to 214 (all multi-ply examples) were almost constant even in areas other than the outer roll area (90%) and the inner roll area (10%), and there was little change in texture across the entire area of the toilet paper, regardless of the length of the toilet paper.

In Comparative Example 201, the winding density of the inner winding region (10%) was almost the same as that of the outer winding region (90%). In addition, the difference in HF value between the outer winding region (90%) and the inner winding region (10%) was large, exceeding 5.0 points, and there was a difference in the quality of the toilet paper between the beginning and end of the toilet roll.

In Comparative Example 202, the winding density of the inner winding region (10%) was higher than that of the outer winding region (90%). In addition, the difference in HF value between the outer winding region (90%) and the inner winding region (10%) was large, exceeding 10 points, and there was a difference in the quality of the toilet paper between the beginning and end of the toilet roll.

In Comparative Example 203, the winding density of the inner winding region (10%) was higher than that of the outer winding region (90%), and the winding density of the outer winding region (90%) was less than 1.0 times that of the inner winding region (10%). In addition, the winding density (100%) calculated as the winding density of the roll-shaped portion in which toilet paper has been wound up to 100% of the winding length was low, and therefore the winding diameter was very large compared to other samples. In addition, the difference in HF value between the outer winding region (90%) and the inner winding region (10%) was large, greatly exceeding 5.0 points, and there was a difference in the quality of the toilet paper between the beginning and end of the toilet roll.

In the non-embossed Comparative Example 204, the winding density of the inner winding region (10%) was almost the same as that of the outer winding region (90%). In addition, the difference in HF value between the outer winding region (90%) and the inner winding region (10%) was large, exceeding 5.0 points, and there was a difference in the quality of the toilet paper between the beginning and end of the toilet roll.

In the above embodiment, the present invention has been described assuming that the toilet roll 10 has a paper tube 14. However, the present invention is not limited to this and can also be applied to a coreless toilet roll that does not have a paper tube 14.

The present invention should be interpreted only from the matters described in the claims, and in the above-described embodiment, any changes or modifications encompassed by the concept of the present invention are possible in addition to the matters described. In other words, all matters in the above-described embodiment are not intended to limit the present invention, and can be freely changed according to the application or purpose, including any configuration not directly related to the present invention.

B Backup roll F Feeding means N Nip roll Vb Rotational speed of backup roll Vf Feeding speed of feed roll Vn Rotational speed of nip roll Vu Payout speed of sheet Vw Winding speed of winding roll W Winding roll 10 Toilet roll 10L Wide toilet roll 11 Sheet 11L Wide sheet 11R Original roll 13 Toilet paper 14 Paper tube (winding core)
14L Wide paper tube 21 Embossing section 25 Perforation forming section 26 Winding section 28c Comb-tooth cutter 28h Rotary blade holder 29c Linear cutter 29h Fixed blade holder 30 Guide roll 32 Guide roll or expander roll 33 Cutter roll

Claims (7)

A toilet roll in which a single ply of toilet paper is wound around a paper tube into a roll,
The length of the roll is more than 90m.
The outer winding density ODE of the toilet roll calculated for the outer winding region of the toilet roll corresponding to the region of the toilet paper in which the length from the end of the toilet roll center side of the toilet roll is in the range of 85% to 95% of the winding length is higher than the inner winding density IDE of the toilet roll calculated for the inner winding region of the toilet roll corresponding to the region of the toilet paper in which the length from the end of the toilet roll center side of the toilet roll is in the range of 5% to 15% of the winding length ,
The toilet roll is characterized in that an outer winding density ODE ₉₀ calculated as the winding density of a roll-shaped portion in which the toilet paper is wound from the end of the toilet roll on the roll center side to a length that is 90% of the winding length is greater than 1.00 and less than 1.50 times an inner winding density IDE 10 calculated as the winding density of a roll-shaped portion in which the toilet paper is wound from the end of the toilet roll on the roll center side to a length that is ₁₀ % of the winding length. 2. The toilet roll according to claim 1 , wherein the outer winding density ODE is 1.15 m/cm ² or more and 1.55 m/cm ² or less, and the inner winding density IDE is 0.80 m/cm ² or more and 1.20 m/cm ² or less. The toilet paper is embossed,
an outer rolled region embossing depth measured with respect to the outer rolled region is less than an inner rolled region embossing depth measured with respect to the inner rolled region;
The outer roll region embossing depth is 80 μm or more and 115 μm or less,
The toilet roll according to claim 1 or 2 , wherein the embossing depth of the inner roll region is 85 μm or more and 145 μm or less. A toilet roll in which toilet paper having a number of plies p (p is an integer of 2 or more) is wound around a paper tube into a roll shape,
The number of plies p and the winding length L (m) satisfy the relationship of the formula L≧90/p,
The outer winding density ODE of the toilet roll calculated for the outer winding region of the toilet roll corresponding to the region of the toilet paper whose length from the end of the toilet roll center side is in the range of 85% to 95% of the winding length L is higher than the inner winding density IDE of the toilet roll calculated for the inner winding region of the toilet roll corresponding to the region of the toilet paper whose length from the end of the toilet roll center side is in the range of 5% to 15% of the winding length L ,
The toilet roll is characterized in that an outer winding density ODE ₉₀ calculated as the winding density of a roll-shaped portion in which the toilet paper is wound from the end of the toilet roll on the roll center side to a length that is 90% of the winding length L is greater than 1.00 times and less than 1.50 times an inner winding density IDE 10 calculated as the winding density of a roll-shaped portion in which the toilet paper is wound from the end of the toilet roll on the roll center side to a length that is ₁₀ % of the winding length L. 5. The toilet roll according to claim 4 , wherein the outer winding density ODE is 1.10 m/cm ² or more and 1.75 m/cm ² or less, and the inner winding density IDE is 0.90 m/cm ² or more and 1.40 m/cm ² or less. 6. The toilet roll according to claim 4 or 5 , wherein the toilet paper is embossed. 7. The toilet roll of claim 6 , wherein the embossment is a single embossment.

Images