JP7494697B2 - Toilet roll and its manufacturing method - Google Patents

Description

The present invention relates to a toilet roll in which two sheets of toilet paper are overlapped and wound into a roll, and a method for manufacturing the same.

Toilet rolls are made of two-ply toilet paper, each consisting of two sheets stacked together, wound into a roll, and by increasing the length of each roll, toilet roll products can be transported and stored in a more compact space.

In order to increase the winding length while maintaining the roll diameter within a specified dimension, it is effective to reduce the basis weight of the sheet, but this generally reduces the strength and also the bulk and usability. Patent Document 1 proposes a toilet roll that ensures the softness of the sheet by making the surface of the sheet uneven, and by focusing on the winding density of the roll, etc., the winding length per roll is increased without reducing the basis weight, ensuring the softness of the sheet and roll.

Cited Document 1 discloses that the uneven shape of the sheet surface is preferably an embossment with a depth of 0.05 mm to 0.40 mm, and that the type of embossing is preferably a single embossing, in which the embossed convex portion is pressed against only one side of the two-ply toilet paper, because double embossing, in which each sheet of two plies is embossed and then superimposed, can result in an excessively thick paper and a low winding density, making it impossible to ensure the proper winding length.

By the way, soft toilet paper generally has tearing perforations that run widthwise of the toilet paper and are spaced at regular intervals along the length of the toilet paper to make it easier to separate the toilet paper from the toilet roll.

JP 2016-198409 A

When a two-ply toilet paper with a single embossing as described above is provided with a tearing perforation, if the roll is wound tightly so that the diameter of the roll falls within a specified range while the roll length is increased, longitudinal misalignment is likely to occur between the two sheets that make up the two-ply toilet paper. This misalignment becomes greater the longer the roll length. Furthermore, this misalignment becomes greater when the paper quality of the sheets is smooth. As a result of the misalignment, the two-ply toilet paper may peel off from each other, making it difficult to pull out the two-ply toilet paper as a unit from the toilet roll, or the perforations of the two sheets that make up the two-ply paper may shift in position, making it impossible to cleanly separate the toilet paper at the perforation.

The present invention aims to provide a two-ply toilet roll that has a roll diameter within a specified dimension, a long winding length per roll, ensures the softness of the toilet paper, and prevents misalignment of perforations and peeling of the plies.

As a result of intensive research to solve the above problems, the present inventors have discovered a toilet roll in which two sheets are overlapped to form a two-ply toilet paper, the toilet roll having a roll length of 40 m or more and 100 m or less, a roll diameter of 100 mm or more and 134 mm or less, a basis weight per sheet of 11 g/m2 or more and 20.5 g/m2 or less, a winding density of the toilet roll of 0.65 m/cm2 or more and 2.05 m/cm2 or less, and the toilet paper has a single embossment on the entire surface of the paper and a bonding to prevent the plies of the two sheets from peeling off. The inventors have found that the above-mentioned problems can be solved by a toilet roll in which a toilet paper has a single embossment and a bonding embossment, and is wound up so that the embossed recesses are on the outside of the roll, the toilet paper has tear perforations that cross the width direction of the toilet paper at regular intervals along the longitudinal direction of the toilet paper, the embossing depth of the single embossment and the bonding embossment is 0.8 mm or less , the bonding embossment is formed so as not to protrude outward in the thickness direction from both the front and back sides of the toilet paper, and the embossing depth of the bonding embossment is deeper than the embossing depth of the single embossment .

Specifically, the present invention has the following configuration.

[1] A toilet roll in which two sheets of toilet paper are overlapped and wound into a roll,
The length of the toilet roll is 40 m or more and 100 m or less,
The roll diameter of the toilet roll is 100 mm or more and 134 mm or less,
The basis weight per sheet is 11 g/m or more and 20.5 g/m or less,
The winding density of the toilet roll is 0.65 m/cm2 or more and 2.05 m/cm2 or less,
The toilet paper has a single embossment on the entire surface of the paper and a joining embossment for preventing ply separation of two sheets, and is wound up so that the embossed recess is on the outside of the roll.
The toilet paper has tearing perforations formed at regular intervals along the length of the toilet paper, which cross the width of the toilet paper.
The embossing depth of the single embossment and the bonding embossment is 0.8 mm or less;
The joining embossments are formed so as not to protrude outward in the thickness direction from both the front and back sides of the toilet paper ,
The toilet roll according to claim 1, wherein the embossing depth of the bonding embossment is deeper than the embossing depth of the single embossment .

[2] The roll length of the toilet roll is 40 m or more and 60 m or less,
The basis weight per sheet is 13.0 g/ ^m2 or more and 20.5 g/ ^m2 or less,
The toilet roll according to [1], characterized in that the winding density of the toilet roll is 0.65 m/ ^cm2 or more and 1.70 m/ ^cm2 or less.

[3] The roll length of the toilet roll is 60 m or more and 80 m or less,
The basis weight per sheet is 12.0 g/ ^m2 or more and 18.5 g/ ^m2 or less,
The toilet roll according to [1], characterized in that the winding density of the toilet roll is 0.85 m/ ^cm2 or more and 1.90 m/ ^cm2 or less.

[4] The roll length of the toilet roll is 80 m or more and 100 m or less,
The basis weight per sheet is 11.0 g/ ^m2 or more and 17.0 g/ ^m2 or less,
The toilet roll according to [1], characterized in that the winding density of the toilet roll is 1.05 m/ ^cm2 or more and 2.05 m/ ^cm2 or less.

[5] A toilet roll according to any one of [1] to [4], characterized in that the embossing depth of the single embossment and the joining embossment is 0.05 mm or more and 0.6 mm or less.

[6] A toilet roll according to any one of [1] to [5], characterized in that the embossing depth of the single embossing and the joining embossing is 0.1 mm or more and 0.4 mm or less.

[7] The toilet roll according to any one of [1] to [6], characterized in that the embossed pattern of the single embossing is a collection of dots set to occupy a specific area, and the arrangement direction of the dots is arranged at an inclined angle to the width direction and length direction of the toilet paper.

[ 8 ] A method for producing a toilet roll, comprising:
A step of performing single embossing on a laminated sheet formed by overlapping two sheets;
applying a bonding embossment to the single-embossed laminated sheet;
forming a tear perforation in the laminated sheet having the bonding embossing;
A step of winding up the laminated sheet having the tear perforations formed thereon into a roll so that the embossed recesses of the single embossing are on the outside of the roll;
Including,
In a single embossing step, an embossing roll is pressed against the surface of the laminated sheet that is to be the outer side of the roll to form embossed recesses having an embossing depth of 0.8 mm or less on the surface;
In the step of applying the bonding embossing, the bonding embossing is formed so as not to protrude outward in the thickness direction from both the front and back sides of the laminated sheet after the bonding embossing is applied ;
A method for manufacturing a toilet roll , characterized in that in the step of applying a bonding embossment, the bonding embossment is formed to have an embossing depth deeper than that of the single embossment .

[ 9 ] The method for producing a toilet roll according to [8], characterized in that the embossing roll has an embossing pattern which is a collection of dots set to occupy a predetermined area, and the embossing pattern is arranged so that its arrangement direction forms an inclined angle with respect to the width direction and length direction of the laminate sheet.

[ 10 ] The method for producing a toilet roll according to any one of [ 8 ] to [ 9 ], characterized in that the toilet roll is the toilet roll according to any one of [1] to [ 7 ].

According to the present invention, it is possible to provide a two-ply toilet roll in which the roll diameter is within a predetermined dimension, the roll length per roll is long, the softness of the toilet paper is ensured, and misalignment of perforations and peeling of the plies are prevented.
Therefore, according to the present invention, it is possible to provide a toilet roll in which the roll diameter is within a predetermined dimension while the roll length per roll is long, thereby saving space during transport and storage, the softness of the toilet paper is ensured, providing an excellent feeling of use, and the misalignment of perforations and peeling of the ply are prevented, thereby preventing inconvenience during use. According to the present invention, it is possible to provide a toilet roll in which the misalignment of perforations and peeling of the ply are prevented, regardless of the paper quality, particularly even when the sheet is very smooth.

FIG. 1 is a diagram illustrating a configuration of a toilet roll according to an embodiment of the present invention. 1 is a diagram illustrating a configuration of toilet paper according to an embodiment of the present invention. FIG. FIG. 4 is a diagram illustrating a method for measuring an embossing depth. FIG. 1 is a diagram showing an example of a manufacturing facility applicable to the manufacture of a toilet roll according to an embodiment of the present invention. FIG. 11 is a diagram illustrating the configuration of toilet paper according to a second embodiment of the present invention.

The toilet roll and its manufacturing method according to the embodiment of the present invention will be described below with reference to the drawings. The following embodiment and drawings are described for illustrative purposes and are not intended to limit the present invention.

First Embodiment
(Toilet roll)
FIG. 1 is a schematic diagram illustrating the configuration of a toilet roll according to an embodiment of the present invention.
Referring to FIG. 1, a toilet roll 10 according to an embodiment of the present invention is a so-called two-ply toilet paper 13, consisting of two overlapping sheets 11 and 12, wound into a roll by a predetermined length around a paper tube 14, which is a cylindrical core.

(Sheet)
Each of the two sheets 11, 12 that constitute the toilet paper 13 is obtained by papermaking a slurry that contains 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.
Examples of non-wood pulps produced using plants or animals other than wood as raw materials 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.
Examples of waste paper pulp produced using waste paper (pulp produced from papermaking) as a raw material include 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., but is not particularly limited to these.

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, so they are appropriately mixed in the specified types and proportions to meet the required quality.

For example, at least one selected from coniferous pulp and hardwood pulp can be preferably used as the pulp component. 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, and more preferably 80/20 or less, even more preferably 70/30 or less.

(Optional ingredients)
Various chemicals may be added to the sheet 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, etc. Examples of dry strength agents include cationic starch, polyacrylamide (PAM), carboxymethyl cellulose (CMC), etc. Examples of wet strength agents include polyamide epichlorohydrin, urea, melamine, thermally crosslinked polyacrylamide, etc. Examples of softeners include anionic surfactants, nonionic surfactants, cationic surfactants, and zwitterionic surfactants, etc. The above optional components may be used alone or in combination of two or more.

In an embodiment of the present invention, the types (paper quality such as material and physical properties) of the two sheets 11, 12 that are stacked on top of each other may be the same or different depending on the required quality, etc.

(Toilet roll length)
In an embodiment of the present invention, the toilet roll winding length, which is the length of the toilet paper 13 wound around the paper tube 14, is 40 m or more and 100 m or less. The winding length can be determined, for example, by actually measuring the length of the toilet paper 13 while unwinding it from the toilet roll 10.
Conventionally, the mainstream toilet paper has a roll length of about 30 m. In contrast, when the roll length of the toilet roll is in the range of 40 m to 100 m, the length of the toilet paper 13 per roll is long, and the effect of saving space when carrying and storing the toilet roll is obtained. When the roll length of the toilet roll exceeds 100 m, the roll diameter of the toilet roll generally becomes large, and the toilet roll 10 becomes difficult to fit into a general toilet roll holder. When the roll length of the toilet roll is less than 40 m, the effect of saving space when carrying and storing is small.

(Toilet roll diameter)
In an embodiment of the present invention, the roll diameter DR of the toilet roll, which is the roll diameter of the toilet paper 13 wound into a roll, is 100 mm or more and 134 mm or less. The roll diameter DR can be measured using, for example, a vernier caliper.
When the toilet roll winding diameter DR is in the range of 100 mm or more and 134 mm or less, the toilet roll 10 can be accommodated in a general toilet roll holder and can be supported therein so as to be freely rotatable. When the toilet roll winding diameter DR is larger than 134 mm, the toilet roll 10 is difficult to accommodate in a general toilet roll holder. In addition, when the toilet roll winding diameter DR is smaller than 100 mm, the toilet roll winding length is limited, making it difficult to save space during transportation and storage by increasing the winding length. In addition, when attempting to secure a long winding length of the toilet roll with a small winding diameter DR, the paper thickness and bulkiness of the toilet paper 13 and the basis weight of the constituent sheets 11 and 12 are limited, making it difficult to ensure a good feeling of use and strength.

(Toilet roll winding density)
In an embodiment of the present invention, the winding density of the toilet roll is 0.65 m/cm ² or more and 2.05 m/cm ² or less. The winding density of the toilet roll is calculated by the following formula (I).
(Winding density) = (Winding length x Number of plies) ÷ (Cross-sectional area of toilet roll) (Formula I)

The cross-sectional area of the toilet roll corresponds to the area of the portion of the side surface of the toilet roll 10 shown in Fig. 1(b) that is constituted by the toilet paper 13. In other words, the cross-sectional area of the toilet roll is the area of a circle whose diameter is the winding diameter DR minus the area of a circle whose diameter is the core diameter DC, which is the outer diameter of the paper tube 14. The cross-sectional area of the toilet roll is calculated by the following formula (II).
(Cross-sectional area) = (Toilet roll roll diameter DR ÷ 2) ² × 3.14 - (Core diameter DC ÷ 2) ² × 3.14 (Formula II)

For example, if the toilet roll 10 has a winding length of 50 m, a winding diameter DR of 118 mm, and a core diameter DC of the paper tube 14 of 38 mm, the toilet paper 13 has two plies, so the winding density is calculated as (50 m x 2) ÷ {(118 mm ÷ 2) ² x 3.14 - (38 mm ÷ 2) ² x 3.14}, which is 1.02 m/cm ² .

When the winding density of the toilet roll is 0.65 m/ ^cm2 or more and 2.05 m/ ^cm2 or less, it is possible to obtain a toilet roll that satisfies the above-mentioned winding diameter and winding length and ensures the softness of the toilet paper. When the winding density of the toilet roll is greater than 2.05 m/ ^cm2 , the sheet is tightly wound, making it difficult to ensure the softness of the toilet paper. When the winding density of the toilet roll is less than 0.65 m/ ^cm2 , the paper thickness and bulkiness are low, and good usability and strength cannot be obtained, or the winding length is short.

(toilet paper)
The toilet paper 13 is a so-called two-ply toilet paper, and has the form of a laminated sheet in which two sheets 11 and 12 are overlapped.

(Basis weight per sheet)
In an embodiment of the present invention, the basis weight per sheet of the two sheets 11 and 12 constituting the toilet paper 13 is 11.0 g/m ² or more and 20.5 g/m ² or less. The basis weight per sheet can be obtained by measuring the basis weight of the two-ply toilet paper 13 in accordance with the provisions of Japanese Industrial Standards JIS P8124 and dividing the basis weight by 2, which is the number of plies. That is, the two-ply toilet paper 13 is conditioned according to the method specified in Japanese Industrial Standards JIS P8111, and the conditioned two-ply toilet paper 13 is cut into a predetermined size, for example, a size of 10 cm x 10 cm, while the two sheets 11 and 12 are stacked, the weight of the cut-out two-ply toilet paper 13 is measured, and the weight is divided by 0.01 m ² , which is the cut-out area of the two-ply toilet paper 13, to measure the basis weight of the two-ply toilet paper 13, and the basis weight is divided by 2, which is the number of plies, to obtain the basis weight per sheet.

When the basis weight per sheet is less than 11.0 g/ ^m2 , the strength is low, and the bulkiness and usability are poor. On the other hand, when the basis weight per sheet is more than 20.5 g/ ^m2 , the paper thickness generally increases, and the roll diameter of the toilet roll increases. In this case, if the roll diameter DR of the toilet roll is to be within the range of the roll diameter according to the embodiment of the present invention described above, it becomes difficult to ensure the roll length of the toilet roll. In addition, if the roll length is to be within the range according to the embodiment of the present invention described above, it becomes necessary to reduce the paper thickness, and the texture of the toilet paper is impaired, such as by reducing the bulkiness and becoming hard.

(Embossed)
1A, in an embodiment of the present invention, an embossed portion 13a and a bonding embossed portion 13b are provided on the surface of toilet paper 13. The embossed portion 13a and the bonding embossed portion 13b can be provided by embossing.

(Embossed part)
In detail, on the toilet paper 13, a large number of embossed portions 13a, each having an embossed recess on one side and an embossed protrusion on the other side, are continuously formed over the entire surface of the paper by repeating the embossing pattern P. Here, in this specification, the term "entire paper surface" does not mean strictly 100% of the paper surface area, but should be construed as meaning approximately 100% of the paper surface area, and preferably 90% or more of the paper surface area.

In the example shown in FIG. 1(1), the embossed pattern P is a collection of dots in a point-symmetric shape, with the embossed portions 13a arranged concentrically, and is set to occupy a roughly square area with sides of approximately 28.5 mm surrounded by a two-dot chain line. Note that the configuration of the embossed pattern P applicable to the embodiment of the present invention is not limited to the example shown in FIG. 1(1).

The toilet paper 13 is wound in the toilet roll 10 so that the embossed recesses are on the outside of the roll and the embossed protrusions are on the inside of the roll. By providing embossed recesses on the outer surface of the toilet paper 13 in this way, the feel of the outer surface of the toilet paper 13 is improved and the softness of the sheet can be improved.

(Embossed)
Embossing refers to a process in which an embossed convex portion is formed on one of the two surfaces of a sheet to be embossed, and an embossed concave portion formed by the back side of the embossed convex portion is formed on the other surface. Embossing can be performed by a known method. For example, embossing may be performed by a "matched" embossing roll in which a male (convex) embossing roll and a female (concave) embossing roll of approximately complementary shapes mesh together, or by a so-called "mismatched" embossing roll in which the male (convex) embossing roll and the female (concave) embossing roll are not identical in shape and apply a shear force to the sheet when they mesh together, or by a male (convex) embossing steel roll and a plain rubber roll.

(Single embossing)
Generally, there are two types of embossing for two-ply toilet paper: so-called double embossing, in which each of the two sheets that are constituent elements of the toilet paper is embossed and then stacked together, and so-called single embossing, in which the two sheets are stacked together and then the entire laminate is embossed. The embossing applied to the embodiment of the present invention is single embossing, in which the sheets 11 and 12 that are constituent elements of the two-ply toilet paper 13 are stacked together and then embossed.

In the case of double embossing, two sheets that have been embossed to increase the paper thickness are stacked together, which increases the overall paper thickness of the toilet paper. Therefore, when trying to wind up the toilet paper into a toilet roll with a specified roll diameter, it may be difficult to increase the roll length. Also, if the embossing depth is made shallow in order to reduce the paper thickness, it may not be possible to provide the sheet with sufficient softness. In contrast, in the case of single embossing, two sheets are stacked together and then embossed, so the overall paper thickness of the toilet paper is kept relatively low. Therefore, in an embodiment of the present invention, by adopting single embossing, it is possible to impart softness to the sheet without increasing the paper thickness.

(embossing depth)
Referring to (a) of Figure 2, in an embodiment of the present invention, the embossing depth D, which is the depth of the embossed recess of the embossed portion 13a of the toilet paper 13, is preferably 0.8 mm or less, more preferably 0.05 mm or more and 0.6 mm or less, and even more preferably 0.1 mm or more and 0.4 mm or less.

As the embossing depth D increases, the unevenness of the embossing becomes more pronounced. The unevenness of the embossing increases the bulk of the toilet paper 13, and the paper thickness T of the toilet paper as a whole increases. Although it depends on the winding length of the roll, if the embossing depth D exceeds the above range, the paper thickness T becomes too high, and the winding diameter DR of the toilet roll 10 exceeds the above specified range, which may make it difficult to hold the toilet roll 10 rotatably in the toilet holder. Also, if the embossing depth D is small and the unevenness of the embossing is insufficient, it may not be possible to impart sufficient softness to the toilet paper 13.

(Method of measuring embossing depth)
A method for measuring the emboss depth D will be described. The emboss depth D can be 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 focus. By repeating the scan in this manner, a light amount super-depth image and a height image (information) that are in focus 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 measuring laser microscope, for example, a product named "One Shot 3D Measuring Macroscope VR-3100" manufactured by KEYENCE Corporation can be used. As an observation, measurement, and image analysis software for laser microscope images, for example, a product named "VR-H1A" can be used. In this embodiment, the measurement is performed under conditions of a measurement magnification of 12 times and a field area of 24 mm x 18 mm. Note that the measurement magnification and field area may be changed as appropriate depending on the size of the embossing desired.

As shown in FIG. 2(b), the embossing depth is measured on the surface of the toilet paper 13 on the sheet 11 side on which the embossed recesses are formed (the surface on the outside of the toilet roll 10). First, the longest part a is found, which is the longest straight-line distance between two opposing points on the periphery of the recesses of the embossed part 13a.

Figure 3(a) shows a height profile on the XY plane taken by a shape measuring laser microscope, and the height of the surface of the toilet paper 13 is represented by shading. The dark areas in Figure 3(a) show individual embossed portions 13a. The longest part a of one embossed portion 13a can be identified from Figure 3(a). By drawing a line segment A-B that crosses this longest part a, the height (measured cross-sectional curve) profile of the embossed portion 13a is obtained as shown in Figure 3(b). At this time, the color shading of the XY plane image indicates the convex portions (non-embossed portions) and concave portions of the embossing on the sheet 11 side of the toilet paper 13, so it is sufficient to determine the line segment A-B so that it crosses the portion where the convex portion and the concave portion are adjacent to each other.

The height profile in FIG. 3(b) is a (measured) cross-sectional curve S that represents the unevenness of the actual sample surface (the surface on the sheet 11 side) of toilet paper 13, and also contains noise (steep peaks due to fiber clumps on the toilet paper surface, whisker-like fibers, and areas without fibers). Therefore, when calculating the height difference of the unevenness, it is necessary to remove such noise peaks.

3C, a "contour curve" W is calculated from the cross-sectional curve S of the height profile, two inflection points P1 and P2 that are upwardly convex are found on this contour curve W, and then the minimum value between the inflection points P1 and P2 is found and this minimum value is set as the minimum depth value Min. Furthermore, the average value of the depth values of the inflection points P1 and P2 is set as the maximum depth value Max.
In this manner, the embossing depth D is calculated by the following formula (III).
Embossing depth D=maximum value Max−minimum value Min (Equation III)
Moreover, the distance (length) on the XY plane between the inflection points P1 and P2 is defined as the length of the longest portion a.

The "contour curve" shown in FIG. 3(c) is a curve obtained by removing surface roughness components with wavelengths shorter than λc: 800 μm (where λc is the "filter that defines the boundary between roughness and waviness components" described in JIS-B0601 "3.1.1.2") from the cross-sectional curve shown in FIG. 3(b) using a low-pass filter. If λc is set to be equal to or smaller than the distance between P1 between adjacent embossed portions 13a (hereinafter also referred to as the emboss pitch), there is a possibility that the peaks will be recognized as noise. Therefore, λc is set to be less than the emboss pitch. For example, when the emboss pitch is 800 μm or less, λc is set to, for example, 250 μm. The distance between P1 between adjacent embossed portions 13a is the distance between two P1s when P1, P2, and P1 are arranged in this order between adjacent embossed portions 13a by similarly determining P1 and P2 for the next embossed portion 13a connected to the left or right of FIG. 3(c).

Similarly, referring to FIG. 2(b), the embossing depth D is also measured for the longest part b, where the linear distance between two opposing points on the periphery of the embossed recess of the embossed part 13a in the direction perpendicular to the longest part a is the longest. The larger of the embossing depths D of the longest part a and the longest part b is adopted as the embossing depth D of that one embossed part 13a. The above measurements are performed on any 10 embossed parts 13a on the surface of the sheet 11 side of the toilet paper 13, and the average value is adopted as the final embossing depth D.

When measuring the embossing depth D, it is measured at a portion that is 10% of the winding length of the toilet roll 10 from the end of the toilet paper 13 on the outer winding side of the toilet roll 10 (the position where the toilet paper 13 begins to be used on the toilet roll 10). For example, if the winding length is 50 m, the embossing depth D is measured at a portion 5 m from the end, which is 10% of 50 m from the end. Note that if the 10% portion of the winding length corresponds to the perforation 15, it is measured at a portion on the outer winding side of the roll than the perforation 15. This is because the embossing depth D changes depending on the degree of crushing of the embossing at the beginning and end of winding the toilet paper 13 on the toilet roll 10. This makes it possible to reduce the influence of the measurement position as a factor in fluctuation of the measurement value.

(Embossment for joining)
1(1), in an embodiment of the present invention, the toilet paper 13 is provided with a bonding embossed portion 13b for bonding the constituent sheets 11, 12 to each other. The bonding embossed portion 13b is provided only in a partial area of the paper surface to prevent ply peeling of the sheets 11, 12 constituting each layer of the toilet paper 13, and defines a bonding area that bonds the sheets 11 and 12 together.

The joining embossed portion 13b may be formed, for example, as shown in FIG. 1(a), on both side edges in the width direction (CD direction) of the toilet paper 13 so as to extend along its length direction (MD direction). The pattern of the joining embossed portion 13b formed in this way is also referred to as an edge embossment.

The edge embossing is provided so as not to overlap the center of the toilet paper in the width direction. This prevents the edge embossing from reducing the texture of the center of the toilet paper surface. The edge embossing may be provided, for example, within a range of 10 to 50 mm from each edge of the toilet paper in the width direction.

In edge embossing, a group of multiple joining embossed portions 13b may be provided continuously in the longitudinal direction. In addition, in edge embossing, a group of multiple joining embossed portions 13b may be provided intermittently in the longitudinal direction.

The joining embossed portion 13b is preferably formed so as not to protrude outward in the thickness direction from either the front or back of the toilet paper 13. By doing so, on both the front and back of the toilet paper, the surface of the joining embossed portion 13b becomes a recess that is at the same level as the surface of the toilet paper or has a height (depth) less than that, so the smooth feel of the surface of the toilet paper is not impaired.

(Emboss depth of embossed part for joining)
The embossing depth of the joining embossed portion 13b can be measured by the same method as the method for measuring the embossing depth of the embossed portion 13a described above. In an embodiment of the present invention, the joining embossing depth, which is the depth of the embossed recess of the joining embossed portion 13b of the toilet paper 13, is preferably 0.8 mm or less, more preferably 0.05 mm or more and 0.6 mm or less, and even more preferably 0.1 mm or more and 0.4 mm or less.

(Tear-off perforations)
1(a), in an embodiment of the present invention, in order to facilitate separation of the toilet paper 13 from the toilet roll 10 after it has been pulled out, the toilet paper 13 has tear perforations 15 extending in the width direction of the toilet paper formed at regular intervals in the longitudinal direction of the toilet paper 13. Taking into consideration the amount of paper needed when using the toilet and ease of use, this regular interval in the longitudinal direction is, for example, 100 to 300 mm, but is not limited to this and can be set as desired.

The number, dimensions, widthwise distribution, etc. of the tearing perforations 15 are determined so that the toilet paper 13 does not tear unintentionally and so that the toilet paper 13 easily tears when a shear force is applied to the toilet paper 13. From the viewpoint of ease of tearing, it is preferable that the tearing perforations 15 extend through the thickness direction of the toilet paper 13 and across both side edges of the toilet paper 13 in the width direction.
The tear perforations may be provided by any known perforating device.

(Examples of a toilet roll manufacturing method and manufacturing equipment according to an embodiment of the present invention)
An example of a method and equipment applicable for manufacturing a toilet roll according to an embodiment of the present invention will be described with reference to Figure 4. The toilet roll 10 can be manufactured, for example, as follows.

(Manufacturing of raw rolls)
Raw rolls 11R, 12R are manufactured to manufacture toilet paper 13 having sheets 11, 12 as components. In detail, using a papermaking machine (not shown), wide (several times to twenty-odd times the width of the toilet roll) and long sheets 11L, 12L are made from a papermaking slurry (paper material) while being wound up, to manufacture raw rolls 11R, 12R on which sheets 11L, 12L are wound. As the papermaking machine, for example, a known papermaking machine such as a twin wire former, a cylinder former, a suction pressed former, or a crescent former 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 include 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 sheets 11L and 12L, adjusting and equalizing the paper thickness, and smoothing the surface. The calendar 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.

(Toilet roll manufacturing)
A toilet roll is manufactured using the raw rolls 11R and 12R. Fig. 4 is a schematic diagram showing an example of a manufacturing facility applicable to the manufacture of the toilet roll according to the embodiment of the present invention. The method described below and the manufacturing facility shown in Fig. 4 are for illustrative purposes and do not limit the present invention.
The web roll 11R and the web roll 12R are rotatably attached to a web roll stand 20, and are driven to rotate by a web sheet pay-out device (not shown) to pay out the sheets 11L and 12L.
The sheets 11L and 12L fed from the original rolls 11R and 12R are wound around a polymerization roller 30, overlapped with each other, and transported to an embossing section 21 disposed downstream of the original roll stand 20. Further downstream of the embossing section 21, a perforation forming section 22 and a winding section 23 are disposed in this order.

The embossing section 21 is, in short, a unit that performs embossing on the sheets 11L and 12L.
The embossing section 21 includes an embossing roll unit 21A and a joining embossing roll unit 21B. The embossing roll unit 21A applies single embossing to the entire surface of the toilet paper 13L, and the joining embossing roll unit 21B applies edge embossing to both side edges in the width direction of the toilet paper 13L.

The embossing roll unit 21A includes an embossing roll 24 and a backup roll 25 that is arranged to be movable in the direction opposite the embossing roll, and the overlapped sheets 11L and 12L are inserted between them.

The embossing roll 24 is rotatable, and the outer peripheral surface of the embossing roll 24 is formed with uneven portions corresponding to the embossing pattern P of the embossed portion 13a shown in FIG. 1. In this example, at least the uneven portion of the embossing roll 24 is formed of metal, while the surface portion of the backup roll 25 is formed of a hard rubber-like elastic material such as elastically deformable hard synthetic rubber.

When the backup roll 25 is pressed against the outer circumferential surface of the embossing roll 24 with a predetermined pressure, a common embossing process (single embossing) is applied to the sheets 11L and 12L passing between them. At this time, the embossing depth of the single embossing formed can be controlled by varying the predetermined pressure when the backup roll 25 is pressed against the outer circumferential surface of the embossing roll 24.

Next, downstream of the embossing roll unit 21A in the embossing section 21, a bonding embossing roll unit 21B having a bonding embossing wheel 26 and a receiving roll 27 facing each other is placed, and the laminate of the sheets 11L and 12L (toilet paper 13L) is inserted between them and pressed to form a bonding embossing section to prevent peeling.

In the embossing section 21, the wide toilet paper 13L formed by stacking sheets 11L and 12L together is sent to the perforation forming section 22 located downstream.

The perforation forming unit 22 forms tearing perforations that cross the width of the toilet paper 13L at regular intervals along the longitudinal direction (MD direction) of the toilet paper 13L. Any known perforation forming means can be used to form the tearing perforations.

In this example, the perforation processing device is provided with 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 rotation axis 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 rotation axis of the rotary blade holder 28h.

The perforation processing device passes the long toilet paper 13L 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 that correspond to the cutting edge of the comb-tooth cutter 28c along the width of the toilet paper 13L, straddling both widthwise edges of the toilet paper 13L.

More specifically, the toilet paper 13L 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 that corresponds to the speed at which the toilet paper 13L passes. As the comb-tooth cutter 28c passes the linear cutter 29c, perforations are formed in the toilet paper 13L. The perforations formed by the comb-tooth cutter 28c and the linear cutter 29c extend across both widthwise edges of the toilet paper 13L, and serve as tearing perforations for separating the toilet paper 13L along its width.

In the perforation forming section 22, the wide toilet paper 13L with the tearing perforations formed therein is sent to the winding section 23 arranged downstream thereof.
In the winding section 23, the tip of the toilet paper 13L delivered from the perforation forming section 22 is wound around a wide (i.e., axially long) paper tube 14L, which serves as the core, using adhesive (pickup glue).

A predetermined length of toilet paper 13L is wound around paper tube 14L to form a roll (log) that will become wide toilet roll 10L (i.e., the dimension in the CD direction is large), and the end of the toilet paper 13L is cut off by cutter roll 31. The end of the log is glued to the surface of the log (the outer peripheral surface of the roll) with adhesive (tail seal glue) to prevent it from unraveling, forming wide toilet roll 10L.
The wide toilet roll 10L is then cut into individual toilet rolls 10 by a cutting section (not shown) to a predetermined width according to product specifications, etc.
The above-mentioned manufacturing method and manufacturing apparatus are merely examples, and do not limit the manufacturing method according to the present invention and applicable manufacturing apparatus.

For example, in the above example, two raw cloth rolls 11R, 12R were mounted on the manufacturing apparatus of Fig. 4, and the sheets 11L, 12L were laminated in the apparatus of Fig. 4. However, the sheets 11L, 12L may be laminated in advance in a separate device such as a winder or ply machine to form a two-ply raw cloth roll, and this single two-ply raw cloth roll may be mounted on the manufacturing apparatus of Fig. 4 to manufacture the toilet roll.
Also, in the winding section 23, instead of the toilet roll 10L, a roll having a longer winding length than the toilet roll 10L may be formed, and this may be mounted as a secondary raw roll on another device having a winding function such as a winder, and the toilet roll may be manufactured through a process of forming a log of a predetermined length.

<Manufacturing method of toilet roll according to an embodiment of the present invention>
Thus, the method for producing a toilet roll according to an embodiment of the present invention generally comprises:
(a) a step of performing single embossing on a laminated sheet formed by overlapping two sheets;
(b) applying a bonding embossment to the single-embossed laminated sheet;
(c) forming a tear perforation in the laminated sheet having the bonding embossment;
(d) winding the laminated sheet having the tear perforations formed therein into a roll so that the embossed recesses of the single embossing are on the outside of the roll;
including.

In the manufacturing method according to the embodiment of the present invention, before the step (a),
(x) forming each of the two sheets;
(y) stacking the two sheets together to form a laminated sheet;
may also include

In the manufacturing method according to the embodiment of the present invention, after the step (d),
(z) cutting the formed wide toilet roll into a product width;
may also include

In addition, the manufacturing method according to the embodiment of the present invention may include or omit other steps as necessary, as long as the effects of the present invention can be achieved.

In the manufacturing method according to an embodiment of the present invention, in the single embossing process, the embossing depth of the embossed recesses can be controlled by changing the embossing pressure conditions under which the embossing roll is pressed against the laminated sheet (toilet paper).

(Action and Effect)
The toilet roll according to this embodiment is a toilet roll in which two sheets of toilet paper are overlapped and wound into a roll.
The length of the toilet roll is 40 m or more and 100 m or less,
The roll diameter of the toilet roll is 100 mm or more and 134 mm or less,
The basis weight per sheet is 11 g/ ^m2 or more and 20.5 g/ ^m2 or less,
The winding density of the toilet roll is 0.65 m/ ^cm2 or more and 2.05 m/ ^cm2 or less,
The toilet paper has a single embossment on the entire surface of the paper and a joining embossment for preventing ply separation of two sheets, and is wound up so that the embossed recess is on the outside of the roll.
The toilet paper has tearing perforations formed at regular intervals along the length of the toilet paper, which cross the width of the toilet paper.
The embossing depth of the single embossing and the bonding embossing is 0.8 mm or less.

According to an embodiment of the present invention having such a configuration, it is possible to provide a two-ply toilet roll in which the roll diameter is within a predetermined dimension, the roll length per roll is long, the softness of the toilet paper is ensured, and misalignment of perforations and peeling of plies are prevented.

Therefore, according to the present invention, a toilet roll can be provided in which the roll diameter is within a predetermined dimension while the roll length per roll is long, thereby saving space during transport and storage, and the softness of the toilet paper is ensured, providing an excellent feel when used, and since misalignment of perforations and peeling of the ply are prevented, there is no inconvenience when using the toilet roll. According to the present invention, it is possible to provide a toilet roll in which misalignment of perforations and peeling of the ply are prevented, regardless of the paper quality, particularly even when the sheet is very smooth.

Second Embodiment
A second embodiment of the present invention will be described with reference to Fig. 5. Unless otherwise specified, configurations applicable to the first embodiment are also applicable to this embodiment.

Figure 5 is a front view illustrating an example of the configuration of toilet paper in a toilet roll according to the second embodiment of the present invention. In this example, the embossed pattern P of the embossed portion 13a of the toilet paper 13 is a collection of dots arranged in a concentric circle, forming a point-symmetric shape, and is set to occupy a substantially square area with one side of about 28.5 mm surrounded by a two-dot chain line. The embossed pattern P is also arranged so that its arrangement direction forms an inclination angle with respect to the width direction and length direction of the toilet paper 13. In this example, the inclination angle of the arrangement direction of the embossed pattern P with respect to the width direction and length direction is 7.5 degrees. Note that in the present invention, the inclination angle need only be 0 degrees, and is not limited to 7.5 degrees.

In this way, the second embodiment of the present invention is characterized in that the embossed pattern P, which is continuously repeated across the entire surface of the toilet paper 13, is arranged so that the arrangement direction is inclined with respect to both the width direction (CD direction, the left-right direction in the figure) and the length direction (MD direction, the up-down direction in the figure) of the toilet paper 13.

(Action and Effect)
When the embossed pattern formed repeatedly over the entire surface of the toilet paper is arranged along the width direction and/or length direction of the toilet paper, the embossed portions tend to pile up in the radial direction of the roll so that they appear at the same position when viewed from the outer circumferential surface of the roll when the toilet paper is wound up. When the embossed portions pile up, a phenomenon occurs in which the piled up portions bulge outward from the outer periphery of the roll. Due to the influence of the bulging portions, it becomes difficult to control the winding diameter of the roll to be small, and as a result, there is a limit to how long the winding length can be increased. In addition, the feel of the toilet roll when held in the hand is no longer uniform around the outer periphery of the roll, and the softness of the roll decreases.

In contrast, in the embodiment of the present invention, the embossed pattern P on the surface of the toilet paper 13 is arranged so as to be inclined with respect to the width direction and the length direction of the toilet paper 13. According to this configuration, in the toilet roll 10 in which the toilet paper 13 is wound, the positions of the stacking of the embossed portions 13a are distributed on the outer circumferential surface of the roll. This suppresses the occurrence of the phenomenon in which the stacked portions bulge out on the outer circumferential surface of the roll. Therefore, according to this embodiment, the effect of reducing the roll winding diameter is higher when compared with toilet rolls other than this embodiment having the same winding length. In addition, according to this embodiment, the roll winding length can be increased when compared with toilet rolls other than this embodiment having the same winding diameter. In addition, according to this embodiment, the variation in winding tightness on the outer circumferential surface of the toilet roll 10 is reduced, and a soft roll is obtained.

The configuration of the embossed pattern P applicable to this embodiment is not limited to the example shown in FIG. 5. For example, the embossed pattern P may be set to occupy an equilateral triangular area on the surface of the toilet paper 13, and the embossed pattern P may be arranged in a dense state. The embossed pattern P may also be one in which the embossed portions 13a are arranged in a spiral shape at regular intervals, or one in which the embossed portions 13a are arranged in a rotationally symmetric shape along an arbitrary curve.

<Preferred aspects of the embodiment of the present invention>
The first and second embodiments of the present invention described above are widely applicable to toilet rolls with a wound length of 40 m or more and 100 m or less. Preferred aspects according to the wound length of the toilet roll are described in more detail below.

(1) When the roll length of the toilet roll is 40 m or more and 60 m or less: (a) The basis weight per sheet is 13.0 g/ ^m2 or more and 20.5 g/ ^m2 or less, preferably 13.5 g/ ^m2 or more and 19.5 g/ ^m2 or less, and more preferably 14.5 g/ ^m2 or more and 17.5 g/ ^m2 or less.
(b) The winding density of the toilet roll is 0.65 m/ ^cm2 or more and 1.70 m/ ^cm2 or less, preferably 0.75 m/ ^cm2 or more and 1.55 m/ ^cm2 or less, and more preferably 0.80 m/ ^cm2 or more and 1.40 m/ ^cm2 or less.

(2) When the roll length of the toilet roll is 60 m or more and 80 m or less: (a) The basis weight per sheet is 12.0 g/ ^m2 or more and 18.5 g/ ^m2 or less, preferably 13.0 g/ ^m2 or more and 17.5 g/ ^m2 or less, and more preferably 14.5 g/ ^m2 or more and 16.5 g/ ^m2 or less.
(b) The winding density of the toilet roll is 0.85 m/ ^cm2 or more and 1.90 m/ ^cm2 or less, preferably 0.95 m/ ^cm2 or more and 1.70 m/ ^cm2 or less, and more preferably 1.00 m/ ^cm2 or more and 1.55 m/ ^cm2 or less.

(3) When the roll length of the toilet roll is 80 m or more and 100 m or less: (a) The basis weight per sheet is 11.0 g/ ^m2 or more and 17.0 g/ ^m2 or less, preferably 12.0 g/ ^m2 or more and 16.0 g/ ^m2 or less, and more preferably 13.0 g/ ^m2 or more and 15.5 g/ ^m2 or less.
(b) The winding density of the toilet roll is 1.05 m/ ^cm2 or more and 2.05 m/ ^cm2 or less, preferably 1.20 m/ ^cm2 or more and 1.95 m/ ^cm2 or less, and more preferably 1.30 m/ ^cm2 or more and 1.80 m/ ^cm2 or less.

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 modified according to the application or purpose, including any configuration not directly related to the present invention.

Papermaking was carried out using the same slurry (stock) for papermaking having a pulp composition of 30% by mass of softwood bleached kraft pulp (NBKP):70% by mass of hardwood bleached kraft pulp (LBKP), and a number of raw rolls were obtained in which the sheets made by papermaking were wound up. Two of the raw rolls were used to manufacture toilet rolls according to the manufacturing equipment and manufacturing method shown in Figure 4, and two-ply toilet rolls of Examples 1 to 3 shown in Table 1 were obtained.
Here, the embossing pattern and its arrangement for single embossing were as shown in FIG.
The following measurements and evaluations were carried out for the toilet rolls of Examples 1 to 3. The measurements were carried out by conditioning the samples in an environment conforming to Japanese Industrial Standard JIS P8111 (temperature 23±1°, humidity 50±2% RH).

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

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

[Toilet roll length [m]]
While unwinding the toilet paper from the manufactured toilet roll, the length of the toilet paper wound around the paper tube from the end to the start was measured. The measurement was performed in increments of 0.5 m, and fractions were rounded down.

[Winding density [m/cm ² ]]
It was calculated according to the following formulas (I) and (II).
(Winding density) = (Winding length x Number of plies) ÷ (Cross-sectional area of toilet roll) (Formula I)
(Cross-sectional area) = (Toilet roll roll diameter DR ÷ 2) ² × 3.14 - (Core diameter DC ÷ 2) ² × 3.14 (Formula II)

[Basis weight (per sheet) [g/m ² ]]
The toilet paper was pulled out from the toilet roll, and the basis weight of the two-ply toilet paper was measured according to Japanese Industrial Standard JIS P8124, and divided by 2, the number of plies, to obtain the basis weight per sheet. Specifically, the two-ply toilet paper was conditioned according to the method specified in Japanese Industrial Standard JIS P8111, and the conditioned two-ply toilet paper was cut into a size of 10 cm x 10 cm while the two sheets were still stacked, the weight of the cut two-ply toilet paper was measured, and the weight was divided by 0.01 ^m2, the cut area of the two-ply toilet paper, to obtain the basis weight of the two-ply toilet paper, and the basis weight was divided by 2, the number of plies, to obtain the basis weight per sheet.

[Emboss depth of single embossing [μm]]
The embossing depth (μm) of the single embossing was measured according to the above-mentioned method of measuring the height difference of the embossing using a shape measuring laser microscope and calculating it. The measurement was performed at a portion corresponding to 10% of the winding length of the toilet roll from the end of the toilet paper on the outer winding side of the roll (the position where the toilet paper 13 begins to be used in the toilet roll 10).

[Emboss depth of joint embossing (edge embossing) [μm]]
The embossing depth (μm) of the joint embossing (edge embossing) was measured according to the above-mentioned method of measuring the height difference of the embossing using a shape measuring laser microscope and calculating it. The measurement was performed at a portion corresponding to 10% of the winding length of the toilet roll from the end of the toilet paper on the outer winding side of the roll (the position where the toilet paper 13 begins to be used in the toilet roll 10).

<Evaluation>
Sensory evaluation was performed for the following items, and the results were expressed with symbols (◎: excellent, ◯: good, △: acceptable, ×: unacceptable).

[Toilet paper softness]
The softer the feel when the toilet paper pulled out from the toilet roll was stroked against the skin, the softer and better the toilet paper was considered to be. In detail, toilet paper that felt painful when stroked against the skin was rated as poor (x), toilet paper that felt hard but not painful was rated as fair (△), toilet paper that felt soft was rated as good (◯), and toilet paper that felt extremely soft was rated as excellent (◎).

[Ply peeling, misalignment of perforations]
The toilet roll was held rotatably by a holder, and 50 cm of toilet paper was pulled out from the toilet roll and repeatedly broken at the perforations in the outer sheet of the roll, and the presence or absence of peeling between the two sheets of the two-ply and the presence or absence of misalignment of the perforations was confirmed.

Products with no ply peeling between the two sheets were rated as excellent (◎), products with some ply peeling but no problem in use were rated as good (◯), products with ply peeling that was usable but inconvenient were rated as acceptable (△), and products with severe ply peeling that caused the two sheets to separate and be difficult to handle as a unit were rated as unacceptable (×).

Those where there was no misalignment of the perforations between the two sheets were rated as excellent (◎), those where there was some misalignment of the perforations but the toilet paper could be neatly torn at the perforation were rated as good (◯), those where there was some misalignment of the perforations but the two sheets could somehow be torn at the perforation by slowly applying shear force little by little were rated as acceptable (△), and those where there was a large misalignment of the perforations and the toilet paper could not be neatly torn at the perforation were rated as unacceptable (×).
The test results are shown in Table 1.

As shown in Table 1, Examples 1 to 3, which have roll lengths of 50 m, 60 m, and 90 m, respectively, all had roll diameters of 100 mm or more and 134 mm or less. In other words, the roll diameters of Examples 1 to 3 are large enough to be rotatably stored in a typical toilet roll holder, and are longer than the conventional mainstream roll length of 30 m, allowing for space-saving transport and storage of the rolls.

In addition, in Examples 1 to 3, the longer the roll length, the higher the winding density, but the embossing depth of the single embossing applied across the entire paper surface was set low at 0.8 mm or less. This made it possible to control the roll diameter to a small size while ensuring the softness of the toilet paper without significantly reducing the basis weight per sheet.

In addition, examples 1 to 3 each had an edge embossed to prevent ply peeling and perforation misalignment.

10 Toilet roll 11, 12, 11L, 12L Sheet 11R, 12R Original roll 13, 13L Toilet paper 13a Embossed portion 13b Joint embossed portion (edge embossed portion)
14, 14L core (paper tube)
20 Original roll stand 21 Embossing section 21A Embossing roll unit 21B Joining embossing roll unit 22 Perforation forming section 23 Winding section 24 Embossing roll 25 Backup roll 26 Joining embossing wheel 27 Receiving roll 28c Comb-tooth cutter 28h Rotary blade holder 29c Linear cutter 29h Fixed blade holder 30 Polymerization roller 31 Cutter roll D Embossing depth DC Core diameter DR Winding diameter P Embossing pattern a, b Longest section

Claims (10)

A toilet roll in which two sheets of toilet paper are overlapped and wound into a roll,
The roll length of the toilet roll is 40 m or more and 100 m or less,
The roll diameter of the toilet roll is 100 mm or more and 134 mm or less,
The basis weight per sheet is 11 g/ ^m2 or more and 20.5 g/ ^m2 or less,
The winding density of the toilet roll is 0.65 m/ ^cm2 or more and 2.05 m/ ^cm2 or less,
The toilet paper has a single embossment on the entire surface of the paper and a joining embossment for preventing the ply separation of the two sheets, and is wound up so that the embossed recess is on the outside of the roll;
The toilet paper has tearing perforations that cross the width of the toilet paper at regular intervals along the longitudinal direction of the toilet paper,
The embossing depth of the single embossment and the bonding embossment is 0.8 mm or less;
The joining embossments are formed so as not to protrude outward in the thickness direction from both the front and back sides of the toilet paper ,
The toilet roll according to claim 1, wherein the embossing depth of the bonding embossment is deeper than the embossing depth of the single embossment . The roll length of the toilet roll is 40 m or more and 60 m or less,
The basis weight per sheet is 13.0 g/ ^m2 or more and 20.5 g/ ^m2 or less,
The toilet roll according to claim 1, characterized in that the winding density of the toilet roll is 0.65 m/ ^cm2 or more and 1.70 m/ ^cm2 or less. The roll length of the toilet roll is 60 m or more and 80 m or less,
The basis weight per sheet is 12.0 g/ ^m2 or more and 18.5 g/ ^m2 or less,
The toilet roll according to claim 1, characterized in that the winding density of the toilet roll is 0.85 m/ ^cm2 or more and 1.90 m/ ^cm2 or less. The roll length of the toilet roll is 80 m or more and 100 m or less,
The basis weight per sheet is 11.0 g/ ^m2 or more and 17.0 g/ ^m2 or less,
The toilet roll according to claim 1, characterized in that the winding density of the toilet roll is 1.05 m/ ^cm2 or more and 2.05 m/ ^cm2 or less. The toilet roll according to any one of claims 1 to 4, characterized in that the embossing depth of the single embossment and the joining embossment is 0.05 mm or more and 0.6 mm or less. The toilet roll according to any one of claims 1 to 5, characterized in that the embossing depth of the single embossment and the joining embossment is 0.1 mm or more and 0.4 mm or less. The toilet roll according to any one of claims 1 to 6, characterized in that the embossed pattern of the single embossing is a collection of dots set to occupy a predetermined area, and the arrangement direction of the dots is arranged at an inclined angle with respect to the width direction and the length direction of the toilet paper.
A method for producing a toilet roll, comprising the steps of:
A step of performing single embossing on a laminated sheet formed by overlapping two sheets;
applying a bonding embossment to the laminated sheet on which the single embossing has been applied;
forming a tear perforation in the laminated sheet on which the bonding embossing has been applied;
A step of winding up the laminated sheet having the tear perforations formed thereon into a roll such that the embossed recesses of the single embossing are on the outside of the roll;
Including,
In the single embossing step, an embossing roll is pressed against the surface of the laminated sheet that is to be on the outer side of the roll to form embossed recesses having an embossing depth of 0.8 mm or less on the surface;
In the step of applying the bonding embossing, the bonding embossing is formed so as not to protrude outward in a thickness direction from both the front and back surfaces of the laminated sheet after the bonding embossing is applied ;
A method for manufacturing a toilet roll , characterized in that in the step of applying a bonding embossment, the bonding embossment is formed to have an embossing depth deeper than that of the single embossment . The method for manufacturing a toilet roll according to claim 8, characterized in that the embossing roll has an embossing pattern which is a collection of dots set to occupy a predetermined area, and the arrangement direction of the embossing pattern is arranged at an inclined angle with respect to the width direction and the length direction of the laminated sheet. The method for producing a toilet roll according to any one of claims 8 to 9 , wherein the toilet roll is the toilet roll according to any one of claims 1 to 7 .

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