Toilet roll and its manufacturing method

Abstract

To provide a toilet roll having a long winding length, saving a space for storage, etc., having the toilet paper with excellent texture and preventing the toilet roller from being rolled back.SOLUTION: A toilet roll is formed by winding up 2-ply toilet paper with two sheets superposed, where the winding length is 33 m or more and 100 m or less, the roll diameter is 100 mm or more and 134 mm or less, a basis weight per sheet is 11 g / m2 or more and 16 g / m2 or less, a TS750 outer surface is 12 dBV2rms or more and 30 dBV2rms or less, and the TS750 inner surface is larger than the TS750 outer surface. The toilet paper includes a first bonding embossment part defining a bonding area where the two sheets tightly adhere to each other, and a second bonding embossment part defining, along with the first bonding embossment part, the bonding area where the two sheets tightly adhere to each other and integrally bonding the two sheets along with the first bonding embossment part.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a toilet roll in which two-ply toilet paper sheets, each consisting of two overlapping sheets, are wound into a roll, and to a method for manufacturing the same. [Background technology]

[0002] In toilet rolls, where toilet paper is wound into a roll, efforts are being made to increase the length of each roll to save space when transporting and storing the rolls. Patent Document 1 focuses on the smoothness of two-ply toilet paper, and proposes a long-rolled toilet roll that improves texture by varying the TS750 values ​​measured by a tissue softness measuring device TSA on both sides of the toilet paper, setting the value on the outer surface to 12 to 27 dBV2rms and the ratio of the values ​​on the inner surface to the outer surface to 1.06 to 2.30. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 6262439 Summary of the Invention [Problem to be solved by the invention]

[0004] When toilet paper is made smooth and its texture improved as described above, when the manufactured toilet roll is used, the smoothness of the toilet paper means that only one of the two sheets that make up the two plies of toilet paper (the sheet on the outer surface of the toilet paper, which is the surface on the outside of the roll) is easily pulled out of the roll and used, while the other sheet (the sheet on the inner surface of the toilet paper, which is the surface on the inside of the roll) remains unused in the roll. This can easily lead to a condition known as "rewinding," in which the stacking order of the two sheets that make up the two plies of toilet paper is reversed.

[0005] Figure 8 is a diagram illustrating the "rewinding" of a toilet roll. Figure 8(a) shows a typical toilet roll 100 in its normal state. Figure 8(b) shows the toilet roll 100 shown in Figure 8(a) in its rewound state. As shown in Figures 8(a) and (b), rewinding reverses the stacking order of the sheets in the two-ply toilet paper 130, with sheet 110, which was previously on the outer side, now on the inner side, and sheet 120, which was previously on the inner side, now on the outer side.

[0006] When a toilet roll is rewound, problems can occur such as the two sheets that make up the toilet paper not being the same length and the ends being misaligned, the toilet paper being difficult to pull out as two plies from the roll and easily falling apart, and if the toilet paper has perforations, the perforations on the two sheets being misaligned.

[0007] The present invention aims to provide a toilet roll that has a long winding length per roll, which saves space when carrying and storing, has an excellent texture, and prevents the toilet paper from rewinding. [Means for solving the problem]

[0008] As a result of intensive research to solve the above problems, the inventors have discovered a toilet roll in which two sheets of toilet paper are overlapped and wound into a roll, the toilet roll having a roll length of 33 m or more and 100 m or less, a roll diameter of 100 mm or more and 134 mm or less, and a basis weight per sheet of 11 g / m 2 More than 16g / m 2The tissue softness measurement device TSA is used to measure the strength of the first maximum peak in the spectrum from the low frequency side (TS750 value), obtained by pressing a bladed rotor from above with a pressure of 100mN onto a toilet paper sample placed with the outer surface of the toilet roll facing up on the sample stage and then rotating it at a rotation speed of 2.0 per second, and measuring the vibration of the sample stage with a vibration sensor. The TS750 outer surface is 12dBV. 2 rms over 30dBV 2 It has been discovered that the above problem can be solved by a toilet roll characterized by having a TS750 inner surface, which is the intensity of the first maximum peak in the spectrum seen from the low frequency side (TS750 value) equal to or less than rms, and a tissue softness measuring device (TSA) is used to measure the vibration of a toilet paper sample placed on a sample stage with the inner side of the roll facing up, by pressing a bladed rotor from above with a pressing pressure of 100 mN and then rotating it at a rotation speed of 2.0 per second, and measuring the vibration of the sample stage with a vibration sensor. The TS750 inner surface is greater than the TS750 outer surface, and the toilet paper has a first bonding embossed portion for defining a bonding area where two sheets will come into close contact with each other, and a second bonding embossed portion that, together with the first bonding embossed portion, defines a bonding area where the two sheets will come into close contact with each other and bonds the two sheets together with the first bonding embossed portion.

[0009] Specifically, the present invention has the following configuration.

[0010] [1] A toilet roll in which two sheets of toilet paper are overlapped and wound into a roll, The roll length of toilet rolls is between 33m and 100m, and the roll diameter is between 100mm and 134mm. The basis weight per sheet is 11g / m 2 More than 16g / m 2 is as follows: Using the tissue softness measuring device TSA, a toilet paper sample is placed on the sample stage with the outer surface of the toilet roll facing up. A bladed rotor is pressed from above with a pressure of 100mN, and then rotated at a speed of 2.0 revolutions per second. The vibration of the sample stage is measured with a vibration sensor. The intensity of the first maximum peak in the spectrum from the low frequency side (TS750 value) is 12dBV. 2 rms over 30dBV 2 is less than or equal to rms, Using the tissue softness measuring device TSA, a toilet paper sample was placed on the sample stage with the inner side of the roll facing up. A bladed rotor was pressed from above with a pressure of 100mN, and then rotated at a speed of 2.0 revolutions per second. The vibration of the sample stage was measured with a vibration sensor. The intensity of the first maximum peak in the spectrum from the low frequency side (TS750 value) was obtained for the TS750 inner surface, which was greater than that of the TS750 outer surface. Toilet paper is a first bonding embossment for defining a bonding area where two sheets are to be closely attached to each other; a second bonding embossed portion that, together with the first bonding embossed portion, defines a bonding area where the two sheets come into close contact with each other, and integrally bonds the two sheets together with the first bonding embossed portion; A toilet roll comprising:

[0011] [2] The toilet roll according to [1], characterized in that the sheet contains wood pulp, and the recycled paper pulp content in the sheet, calculated by the formula R÷(W+R)×100, where W is the wood pulp content in the sheet and R is the recycled paper pulp content in the sheet, is 0% by mass or more and less than 40% by mass. [3] A toilet roll in which two sheets of toilet paper are overlapped and wound into a roll, The roll length of toilet rolls is between 33m and 100m, and the roll diameter is between 100mm and 134mm. The basis weight per sheet is 11g / m 2 More than 16g / m 2 is as follows: Using the tissue softness measuring device TSA, a toilet paper sample is placed on the sample stage with the outer surface of the toilet roll facing up. A bladed rotor is pressed from above with a pressure of 100mN, and then rotated at a speed of 2.0 revolutions per second. The vibration of the sample stage is measured with a vibration sensor. The intensity of the first maximum peak in the spectrum from the low frequency side (TS750 value) is 12dBV. 2 rms over 30dBV 2 is less than or equal to rms, Using the tissue softness measuring device TSA, a toilet paper sample was placed on a sample stage with the inner side of the toilet roll facing up, and a bladed rotor was pressed from above with a pressing pressure of 100mN, and then rotated at a speed of 2.0 revolutions per second. The vibration of the sample stage was measured with a vibration sensor, and the intensity of the first maximum peak (TS750 value) of the spectrum seen from the low frequency side was obtained. The TS750 inner surface was greater than the TS750 outer surface. Toilet paper is a first bonding embossment for defining a bonding area where two sheets are to be closely attached to each other; a second bonding embossed portion that, together with the first bonding embossed portion, defines a bonding area where the two sheets come into close contact with each other, and integrally bonds the two sheets together with the first bonding embossed portion; A method for producing toilet paper comprising: The method includes a forming step of forming two-ply toilet paper by overlapping two sheets, and a winding step of winding the formed two-ply toilet paper into a roll with a predetermined length and a predetermined winding diameter, The forming process is 12dBV on the outside of the TS750. 2 rms over 30dBV 2 rms or less, and the inside of the TS750 is larger than the outside of the TS750. (1) A no-embossing process in which two sheets of different paper quality are used and the two sheets are overlapped without embossing the entire surface of each sheet. (2) A double embossing process in which two sheets of the same or different paper quality are used, and the entire surface of each of the two sheets is embossed under different embossing conditions, and then the two sheets are stacked together. (3) A single embossing process in which two sheets of the same or different paper quality are used, and the two sheets are stacked together and embossed all over the surface of the two sheets at once. a first step selected from the following: a second step of performing a bonding embossing process after the first step to form a first bonding embossed portion for defining a bonding area where the two sheets will adhere to each other, and a second bonding embossed portion for defining a bonding area where the two sheets will adhere to each other together with the first bonding embossed portion and integrally bonding the two sheets together with the first bonding embossed portion; A method for producing toilet rolls, comprising: [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a toilet roll that has a long winding length per roll, which saves space when carrying and storing, has an excellent texture, and prevents the toilet paper from rewinding. [Brief explanation of the drawings]

[0013] [Figure 1] 1 is an external view showing an example of the configuration of a toilet roll according to an embodiment of the present invention. FIG. [Figure 2] FIG. 1 is a schematic cross-sectional view of a tissue softness measuring device TSA. [Figure 3] 1 is a schematic cross-sectional view of an example of a sample measured by the measurement device TSA. [Figure 4] FIG. 2 is a diagram illustrating the measurement principle of the measurement device TSA. [Figure 5] FIG. 2 is a diagram illustrating the measurement principle of the measurement device TSA. [Figure 6] FIG. 10 is a diagram showing an example of a measurement result obtained by the measurement device TSA. [Figure 7] FIG. 1 is a schematic diagram showing an example of manufacturing equipment applicable to the manufacture of toilet rolls. [Figure 8] FIG. 10 is a diagram illustrating rewinding of toilet paper. [Figure 9] 10A and 10B are diagrams showing examples of the structure of the joining embossed portion. DETAILED DESCRIPTION OF THE INVENTION

[0014] (Embodiment) A toilet roll according to an embodiment of the present invention will now be described with reference to the drawings. The following embodiments and drawings are provided for illustrative purposes and are not intended to limit the present invention.

[0015] (Toilet roll) FIG. 1 is a schematic external view illustrating an example of the configuration of a toilet roll according to an embodiment of the present invention.

[0016] 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, which is made up of two overlapping sheets 11 and 12, wound into a roll of a predetermined length around a paper tube 14, which is a cylindrical core.

[0017] (sheet) Each of the two sheets 11 and 12 that make up the toilet paper 13 is obtained by papermaking a slurry containing a pulp component, which is a fiber raw material. The two sheets 11 and 12 may be of the same or different paper quality.

[0018] (pulp component) Pulp components include wood pulp, non-wood pulp, and recycled paper pulp.

[0019] 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-groundwood pulp (CGP), and mechanical pulps such as groundwood pulp (GP), and thermomechanical pulp (TMP, BCTMP), but are not limited thereto.

[0020] 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.

[0021] Examples of waste paper pulp produced using waste paper (pulp produced from papermaking) as a raw material include, but are not limited to, so-called milk carton pulp, which is made from paper cartons used to fill and package liquids, such as milk cartons, and deinked pulp, which is made from newspapers, magazines, etc.

[0022] The pulp component may be one of the above types, or a mixture of two or more types. These pulp components have a significant effect on the quality of the toilet paper 13, so they are appropriately blended in a predetermined type and blending ratio according to the required quality.

[0023] For example, only wood pulp (100% by mass) can be used as the pulp component. At least one selected from softwood pulp and hardwood pulp can be preferably used as the wood pulp. Softwood pulp has long, strong fibers and can impart strength to the sheet produced. Hardwood pulp has short, 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 softwood pulp and hardwood pulp in combination, and it is more preferable to use softwood kraft pulp (NKP) and hardwood kraft pulp (LKP) in combination.

[0024] 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 preferably, for example, 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.

[0025] (optional ingredient) Various chemicals may be added as optional components to the sheets 11 and 12 to achieve the required quality and stabilize operations. Examples of optional components include dry strength agents, wet strength agents, softeners, bulking agents, dyes, fragrances, dispersants, drainage aids, pitch control agents, retention aids, and sizing agents. Examples of dry strength agents include cationized starch, polyacrylamide (PAM), and carboxymethyl cellulose (CMC). Examples of wet strength agents include polyamide epichlorohydrin, urea, melamine, and thermally crosslinkable polyacrylamide. Examples of softeners include anionic surfactants, nonionic surfactants, cationic surfactants, and zwitterionic surfactants. The above optional components may be used alone or in combination.

[0026] In the embodiment of the present invention, the types (paper quality such as material and physical properties) of the two sheets 11 and 12 to be superimposed on each other may be the same or different depending on the required quality and the like.

[0027] One end (starting 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) (not shown). This allows the toilet paper 13 to be wound around the paper tube 14 when the toilet roll 10 is manufactured, and also prevents the toilet paper 13 from peeling off and becoming detached from the paper tube 14 in the toilet roll 10.

[0028] (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 inner diameter of the cardboard tube 14 is set according to the size of the components (core, hooks, etc.) of the toilet roll holder that support the rotation of the toilet roll 10. For example, the inner diameter according to the Japanese Industrial Standards (JIS) is 38 mm (±1 mm), and the core diameter DC, which is the outer diameter of the cardboard tube 14, is generally around 38 mm to 40 mm, although this depends on the thickness of the cardboard tube 14.

[0029] The material of the cardboard tube 14 may be any material that can be coated on its outer surface with pick-up glue, pick up and glue the beginning end of the toilet paper 13, and wind the toilet paper 13, and is often made from cardboard such as cardboard tube base paper, cardboard base paper, or kraft paper. The cardboard tube 14 may also be made from a strip of paper wound in a spiral shape, for example.

[0030] (Pickup glue) The pick-up glue is an adhesive for adhering and fixing the beginning end of the toilet paper 13 to the outer surface of the paper tube 14. There are no particular restrictions on the type of adhesive, but it is preferable that the adhesive be one that can quickly adhere and fix the toilet paper 13 and has an adhesive strength that can withstand the tensile force when the toilet paper 13 is wound up. As such an adhesive, a water-soluble adhesive is preferable, and a cellulose derivative adhesive is more preferable. Among commercially available cellulose derivative adhesives, for example, Kanebinol TV976 and Kanebinol TV986 (both trade names, manufactured by Nippon NSC Co., Ltd.) are preferably used because they have strong wet tack and excellent pick-up properties.

[0031] (Toilet roll length) In an embodiment of the present invention, the roll length of the toilet roll 10, which is the length of the toilet paper 13 wound around the paper tube 14, is 33 m or more and 100 m or less. The roll length can be determined, for example, by actually measuring the length of the toilet paper 13 while unwinding it from the toilet roll 10.

[0032] When the roll length of the toilet roll 10 is within this range, the length of toilet paper 13 per roll is long, making it possible to save space when carrying and storing the toilet roll 10. When the roll length of the toilet roll 10 exceeds 100 m, the diameter of the roll of the toilet roll 10 generally becomes large, making it difficult for the toilet roll 10 to fit into a typical toilet roll holder. Furthermore, when the roll length of the toilet roll 10 is less than 33 m, the roll length per roll is short, making it difficult to save space when carrying or storing the toilet roll 10.

[0033] (Toilet roll diameter) In an embodiment of the present invention, the roll diameter DR of the toilet roll 10, 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.

[0034] When the roll diameter DR of the toilet roll 10 is within this range, the toilet roll 10 can fit into a typical toilet roll holder and be supported rotatably therein. If the roll diameter DR of the toilet roll 10 is larger than 134 mm, the toilet roll 10 will have difficulty fitting into a typical toilet roll holder. Furthermore, if the roll diameter DR of the toilet roll 10 is smaller than 100 mm, the roll length of the toilet roll 10 is limited, making it difficult to save space during transport and storage by increasing the roll length. Furthermore, attempting to ensure a long roll length of the toilet roll 10 with a small roll diameter DR limits the paper thickness and bulk of the toilet paper 13 and the basis weight of the constituent sheets 11 and 12, making it difficult to ensure a good feel in use and strength.

[0035] (Toilet roll density) The winding density of the toilet roll 10 is calculated by the following formula (I).

[0036] (Winding density) = (winding length x number of plies) ÷ (cross-sectional area of ​​toilet roll) (Equation I)

[0037] The cross-sectional area of ​​the toilet roll 10 corresponds to the area of ​​the portion of the side of the toilet roll 10 shown in Figure 1(b) that is made up of toilet paper 13. In other words, the cross-sectional area of ​​the toilet roll 10 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 of the paper tube 14. The cross-sectional area of ​​the toilet roll 10 is calculated using the following formula (II):

[0038] (Cross-sectional area) = (Toilet roll diameter DR ÷ 2) 2 ×3.14-(core diameter DC÷2) 2 ×3.14 (Formula II)

[0039] For example, if the toilet roll 10 has a roll length of 37.5 m, a roll diameter DR of 117 mm, and a core diameter DC of the paper tube 14 of 40 mm, the toilet paper 13 has two plies, so the roll density is (37.5 m × 2) ÷ {(117 mm ÷ 2)} 2×3.14-(40mm÷2) 2 × 3.14} to get 0.79 m / cm 2 This becomes:

[0040] (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 superimposed.

[0041] (basis weight per sheet) In the embodiment of the present invention, the basis weight of each of the two sheets 11 and 12 constituting the toilet paper 13 is 11 g / m 2 More than 16g / m 2 The basis weight per sheet can be calculated by measuring the basis weight of the two-ply toilet paper 13 and dividing the basis weight by 2, the number of plies, in accordance with the provisions of Japanese Industrial Standard JIS P8124. That is, the two-ply toilet paper 13 is conditioned according to the method specified in Japanese Industrial Standard JIS P8111, and the conditioned two-ply toilet paper 13 is cut into a predetermined size, for example, 10 cm x 10 cm, while the two sheets 11, 12 remain stacked, and the weight of the cut two-ply toilet paper 13 is measured and multiplied by 0.01 m of the cut area of ​​the two-ply toilet paper 13. 2 The basis weight of the two-ply toilet paper 13 is measured by dividing by 1 / 2, which is the number of plies, to obtain the basis weight per sheet.

[0042] The basis weight per sheet is 11g / m 2 If the weight is less than 16g / m, the strength will be low and the feeling of use will be poor due to the decrease in water absorption. 2If the thickness exceeds this range, the paper thickness will generally increase and the roll diameter of the toilet roll 10 will become larger. If the roll diameter of the toilet roll 10 is to be kept within the above range, it will be difficult to ensure the roll length of the toilet roll 10. Furthermore, if a roll length within the above range is to be obtained, it will be necessary to reduce the thickness of the sheets 11 and 12, which may cause the sheets 11 and 12 to become crushed and impair the texture of the toilet paper 13.

[0043] In the embodiment of the present invention, the toilet paper 13 is characterized in that a partial area of ​​the sheet is embossed for joining, in order to join two sheets that make up the two plies.

[0044] Furthermore, in an embodiment of the present invention, the toilet paper 13 may be an embossed product in which the entire sheet (entire surface) is embossed for the purpose of adding a pattern or changing the feel to improve the texture, or it may be a non-embossed product that has not been embossed in this way. If the toilet paper 13 is an embossed product, the embossing specification may be so-called single embossing or so-called double embossing. Embossing and bonding embossing will be described below.

[0045] (embossed) Embossing refers to a process in which embossed convex portions are formed on one of the two surfaces of a sheet to be embossed, and embossed concave portions, consisting of the backsides of the embossed convex portions, are formed on the other surface. Embossing can be performed by known methods. For example, embossing may be performed using "matched" embossing rolls, in which a male (convex) embossing roll and a female (concave) embossing roll of approximately complementary shapes engage with each other; alternatively, embossing may be performed using so-called "mismatched" embossing rolls, 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 engage with each other; or alternatively, embossing may be performed using a male (convex) embossing steel roll and a plain rubber roll.

[0046] (1) Embossing the entire sheet (entire surface) The embossing in one embodiment of the present invention shown in Figure 1 is so-called single embossing. That is, in toilet paper 13, its constituent sheets 11 and 12 are stacked on top of each other and then embossed as a whole. In the example of Figure 1, toilet paper 13 has a large number of embossed portions 13a that protrude toward the inside of the roll formed in a repeating pattern across the entire surface (whole surface) of the paper.

[0047] In this manner, in this embodiment, the embossed portion 13a is protruded on the inner surface of the toilet paper 13, which is the surface that faces the inside of the roll, and an embossed recess is provided on the outer surface of the toilet paper 13, which is the surface that faces the outside of the roll, thereby making the outer surface of the toilet paper 13 smooth to the touch and reducing the smoothness of the inner surface.

[0048] In the embodiment of the present invention, the embossed pattern may be any pattern other than those described above. For example, in one aspect of the embodiment of the present invention, the embossed pattern may be a so-called double embossed pattern. That is, in the toilet paper 13, each or one of the constituent sheets 11 and 12 may be embossed entirely before being stacked together.

[0049] In one aspect of the embodiment of the present invention, the sheets 11 and 12 that are components of the toilet paper 13 may not be embossed in their entirety. In other words, the toilet paper 13 may be a non-embossed product in which a repeating pattern is not formed over the entire surface (whole surface).

[0050] (2) Embossing for joining In an embodiment of the present invention, from the viewpoint of preventing rewinding of the toilet roll 10, the toilet paper 13 is provided with embossed joining sections (e.g., embossed sections 13e (11e, 12e) in FIG. 1(a)) for joining the constituent sheets 11, 12 to each other in order to prevent the sheets 11, 12 that make up each layer of the toilet paper 13 from peeling from each other. The embossed joining sections 13e (11e, 12e) define a joining area that integrally joins the sheets 11 and 12. The embossed joining sections 13e (11e, 12e) may be formed in a repeating pattern on both side edges in the width direction (CD) of the toilet paper 13 so as to extend along its longitudinal direction (MD), and when formed in this manner, they are also referred to as edge embossments. The embossed joining sections 13e (11e, 12e) may be formed so as not to protrude outward in the thickness direction from both the front and back sides of the toilet paper 13.

[0051] 9 is a diagram showing an example of the structure of the joining embossed portions 13e (11e, 12e). Referring to (a) of FIG. 9, the toilet paper 13 is provided with a first joining embossed portion 11e for defining a joining area where the two sheets 11, 12 constituting the two plies are in close contact with each other, and a second joining embossed portion 12e for defining a joining area where the two sheets 11, 12 are in close contact with each other together with the first joining embossed portion 11e and for integrally joining the two sheets 11, 12 together with the first joining embossed portion 11e. The joining of the two sheets 11, 12 by the joining embossed portions prevents peeling of the two sheets 11, 12, and therefore prevents the toilet roll from rewinding.

[0052] FIG. 9(b) shows a pair of metal embossing rolls 16 and 17 used to form the joining embossed portion 13e (11e, 12e) shown in FIG. 9(a).

[0053] Fig. 9(c) shows another example of bonding embossed areas 11e, 12e formed by a pair of metal embossing rolls 16, 17 shown in Fig. 9(b). As shown in Fig. 9, even when the same processing rolls are used, bonding embossed areas of various patterns can be formed depending on the processing conditions, thereby making it possible to vary the texture and appearance of the bonding embossed area.

[0054] (TS750 value obtained by tissue softness measuring device TSA) In an embodiment of the present invention, the TS750 values ​​obtained by a tissue softness measuring device TSA (hereinafter also simply referred to as the measuring device TSA) are specified for both sides of the toilet paper 13. Before describing the specific range of TS750 values ​​according to an embodiment of the present invention, the tissue softness measuring device TSA, the measurement principle, and the measurement procedure used to obtain the TS750 values ​​will be described with reference to Figures 2 to 6.

[0055] (Tissue Softness Measurement Device TSA) 2 is a schematic cross-sectional view of a tissue softness measuring device TSA manufactured by Emtec Electronic GmbH of Germany, which can be used to obtain the TS750 value according to an embodiment of the present invention. The measuring device TSA is available from Nippon Luft Co., Ltd. (a distributor in Japan).

[0056] The human feel (tactile sensation) when touching toilet paper 13 is affected by three characteristics of the toilet paper 13: "softness," "smoothness / roughness," and "stiffness." The TSA measuring device is capable of quantifying parameters (referred to as TS7, TS750, and D, respectively) that are indicators of these three characteristics through acoustic and deformation measurements. The TSA measuring device can calculate a value known as the hand feel (HF) value by performing an algorithmic analysis based on these obtained parameters (raw data) and the basis weight, thickness, number of plies, etc. of the toilet paper 13. The HF value is a value used for a comprehensive quantitative evaluation of the tactile sensation of toilet paper 13, correlated with the results of a human tactile sensation (panel test).

[0057] Of the parameter values ​​mentioned above, TS7 (softness), TS750 (smoothness / roughness), and D (stiffness), the TS7 and TS750 values ​​can be obtained by acoustic measurement using the tissue softness measuring device TSA.

[0058] (Principle of Acoustic Measurement by Tissue Softness Analyzer TSA) The measurement principle of acoustic measurement by the tissue softness measuring device TSA will be described with reference to FIGS.

[0059] FIG. 3 is a schematic cross-sectional view showing an example of a sample of toilet paper 13 to be measured by the tissue softness measuring device TSA. In an embodiment of the present invention, the sample 23 to be measured by the measuring device TSA 20 is a two-ply toilet paper 13 consisting of two sheets 11 and 12, but in FIG. 3, the sample 23 is shown schematically as a single sheet. The sample 23 has an uneven texture. Furthermore, raised portions, which are protrusions originating from the constituent fibers 23f, can be seen on the surface of the sample 23. Raising is also called fiber fluffing, and the roots of the raised fibers are present on the surface or inside of the sample 23.

[0060] 2(a), in the tissue softness measuring device TSA 20, a vibration sensor 21a is located inside a sample stage 21, and a bladed rotor 25 that rotates a blade 25a by a motor 25b is located above the sample stage 21. The sample 23 is attached to the sample stage 21 like a drumhead, with the surface to be measured facing upward, i.e., with the measurement surface facing the bladed rotor 25.

[0061] In the first measurement step, the bladed rotor 25 is lowered vertically, and the blade 25a presses against the sample 23 with a set load, as shown in Figure 2(b). Then, while maintaining a constant vertical position, the blade 25a is rotated at a set speed. The resulting horizontal movement of the blade 25a on the sample 23 generates different types of vibrations and noise. The generated vibrations and noise are detected by the vibration sensor 21a. The detected vibrations and noises are analyzed for frequency using a PC to obtain the TS750 value. For example, the TS750 value can be automatically obtained using the emtec measurement system, a software developed by Emtec.

[0062] In detail, referring to Fig. 4, during measurement by the measuring device TSA 20, the blade 25a is moved horizontally at a constant vertical position, as exemplified by the movement from position (1) to (3) in the figure. Such horizontal movement of the blade 25a causes the position of the sample 23 to fluctuate, inducing vertical vibration of the sample 23. The induced vibration frequency depends on the structural dimensions of the toilet paper 13 (e.g., dimensions resulting from creep, embossment, etc.) and the rotation speed of the blade 25a. The amplitude (strength) of the vibration depends on the structural height.

[0063] 5, during the above-described measurement by the measuring device TSA 20, the blade 25a, which is moved horizontally at a constant vertical position, advances horizontally on the surface of the sample 23, as exemplified by the movement from position (i) to (iii) in the figure. At this time, the blade 25a makes instantaneous contact with the fibers 23f protruding from the sample surface, causing the blade 25a to vibrate, which induces horizontal vibration of the blade 25a itself.

[0064] Compared to Figure 5(a), in Figure 5(b), the fiber 23f is soft, and when the blade 25a and the fiber 23f come into contact, the fiber 23f bends significantly, resulting in less bending of the blade 25a. This results in a relatively smaller amplitude of the induced horizontal vibration of the blade 25a. The amplitude of the horizontal vibration of the blade 25a depends on the softness or hardness of the fiber 23f (the rigidity of each fiber), the internal structure of the material of the sample 23 (bulk, fiber bond strength), micro- and macro-compressibility, and added chemicals (softener, starch, dry strength agent). The resonant frequency is constant, approximately 6,500 Hz, depending on the material and geometric dimensions of the sample 23.

[0065] FIG. 6 shows an example of a frequency spectrum obtained as a result of acoustic measurement using the measurement device TSA 20. The horizontal axis represents frequency (unit: Hz) and the vertical axis represents amplitude (intensity) (unit: dBV). 2 The resulting spectrum generally consists of two overlapping single spectra.

[0066] As explained with reference to Figure 4, the single spectrum based on the vertical vibration of sample 23 appears as the first maximum peak P1 in the spectrum viewed from the low frequency side. The intensity (amplitude) of maximum peak P1 is the TS750 value, which is an index of the "smoothness / roughness" of sample 23. The smaller the TS750 value, the smoother the sample 23 is evaluated to be.

[0067] The single spectrum based on the horizontal vibration of blade 25a, as described with reference to Figure 5, appears as a maximum peak P2 in the spectrum including (around) 6500 Hz, which is the resonant frequency. The intensity (amplitude) of maximum peak P2 is the TS7 value, which is an index of the "softness" of sample 23. The smaller the TS7 value, the softer the sample 23 is evaluated to be.

[0068] In addition, in the measurement device TSA 20, as a second measurement step, a D value representing the "rigidity" of the sample 23 can be obtained by measuring deformation by repeating a cycle of changing the load applied to the sample 23. A hand feel (HF) value can be obtained using a nonlinear algorithm from the obtained D value, the aforementioned TS7 value and TS750 value, and the paper thickness, basis weight, number of plies, etc. These D value and HF value are not numerical values ​​defined in the embodiments of the present invention, so further explanation of them will be omitted in this specification.

[0069] (TS750 value measurement procedure) The TS750 value can be measured using the tissue softness measuring device TSA 20 according to the following procedure.

[0070] (1) Sample preparation The toilet paper 13 is unwound from the toilet roll 10, and a circular toilet paper sample 23 having a diameter of 112.8 mm is cut out. The sample 23 includes a set of two sheets 11 and 12 that make up the toilet paper 13. An Emtec sample punch may be used to cut out the sample 23.

[0071] (2) Mounting the sample The sample 23 is placed on the circular sample stage 21 with the measurement surface of the sample 23 facing upward (i.e., toward the bladed rotor 25). Next, the sample fixing ring 24 is pressed down to hold the outer periphery of the sample 23, thereby locking the sample 23 onto the sample stage 21.

[0072] (3) Measurement The bladed rotor 25 is pressed onto the sample 23 with a pressure of 100 mN. Then, the motor 25b is activated to rotate the bladed rotor 25 at a speed of 2.0 rpm. The vibration of the sample stage 21 at this time is measured by the vibration sensor 21a installed inside the sample stage. Software is used to analyze the vibration frequency and automatically obtain the TS750 value.

[0073] (4) Calculation of the average value For 10 toilet rolls of one type, steps (1) to (3) above are repeated to perform a total of 10 measurements, and the TS750 value is obtained as the average value.

[0074] (TS750 value) Here, the TS750 value of the toilet roll 10 according to the embodiment of the present invention is defined as follows.

[0075] (TS750 external surface) Using the tissue softness measuring device TSA 20, the toilet paper 13 is placed on the sample stage 21 with the outer surface of the toilet roll 10 facing up. The bladed rotor 25 is pressed from above with a pressing pressure of 100 mN, and then rotated at a rotation speed of 2.0 per second. The vibration of the sample stage 21 is measured with the vibration sensor 21a. The TS750 outer surface, which is the intensity of the first maximum peak (TS750 value) of the spectrum seen from the low frequency side, is 12 dBV. 2 rms over 30dBV 2 is less than rms.

[0076] TS750 exterior: 12dBV 2 rms over 30dBV 2 When the TS750 outer surface is 12 dBV or less, the surface of the toilet paper 13 on the outside of the toilet roll 10 (also called the outer surface of the toilet paper) becomes smooth and has an excellent texture. 2 If the rms is less than 30 dBV, the toilet paper 13 will have a slippery texture, which is not desirable, and manufacturing will be difficult. 2If it is greater than rms, the outer surface of the toilet paper 13 will not be sufficiently smooth, and a good texture will not be obtained.

[0077] (Difference D (TS750 inner surface - TS750 outer surface)) Using the tissue softness measuring device TSA 20, toilet paper 13 is placed on a sample stage with the inner side of the toilet roll 10 (also called the inner side of the toilet paper) facing up. The bladed rotor 25 is pressed from above with a pressing pressure of 100 mN against the toilet paper 13, and then rotated at a rotation speed of 2.0 per second. The vibration of the sample stage 21 is measured with the vibration sensor 21a. The difference D (TS750 inner surface - TS750 outer surface) between the TS750 inner surface, which is the intensity of the first maximum peak of the spectrum seen from the low frequency side (TS750 value), and the above-mentioned TS750 outer surface, is 0 dBV. 2 rms, i.e., the TS750 inner surface is larger than the TS750 outer surface, which means that the inner surface of the toilet paper 13 is rougher than the outer surface of the toilet paper 13.

[0078] The above TS750 external surface (12dBV 2 rms over 30dBV 2 rms or less), and the difference D (TS750 inside surface - TS750 outside surface) is 0 dBV. 2 When the smoothness is rms or less, the inner surface of the toilet paper 13 is as smooth as or smoother than the outer surface of the toilet paper 13. In this case, the texture of the inner surface as well as the outer surface of the toilet paper is improved, but the inner sheet and outer sheet of the two-ply toilet paper 13 tend to slip, causing the two-ply toilet paper 13 to peel off when the toilet paper 13 is pulled out from the toilet roll 10, and as a result, the toilet roll 10 is likely to rewind.

[0079] On the other hand, the above-mentioned TS750 outer surface (12dBV 2 rms over 30dBV 2 rms or less), and the difference D (TS750 inside surface - TS750 outside surface) is 0 dBV.2 When the rms is larger, the toilet paper 13 has a moderately smooth outer surface with an excellent texture, and the inner surface is rougher than the outer surface, so the inner sheet and the outer sheet of the two-ply toilet paper 13 do not slide easily, preventing the plies of the two-ply toilet paper 13 from peeling off when the toilet paper 13 is pulled out from the toilet roll 10, and as a result, preventing the toilet roll 10 from rewinding.

[0080] (Examples of manufacturing methods and manufacturing equipment applicable to embodiments of the present invention) Examples of methods and equipment applicable to manufacturing toilet rolls according to embodiments of the present invention will be described with reference to Figures 1 and 7. The toilet roll 10 can be manufactured, for example, as follows.

[0081] (Manufacturing raw rolls) Raw rolls 11R, 12R are manufactured to produce the sheets 11, 12, which are components of the toilet paper 13. In detail, a papermaking machine (not shown) is used to make and wind wide (several times to twenty-odd times the width of the toilet roll) and long sheets 11L, 12L from a papermaking slurry (stock), thereby manufacturing the raw rolls 11R, 12R on which the 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-press former, or a crescent former can be used.

[0082] 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 impart very fine wavy wrinkles called crepes to the sheet as needed while the sheet (web) being made is being dried. Creping can impart softness, bulkiness (bulk), absorbency, aesthetic appearance (crepe shape), and a pleasant feel to the sheet.

[0083] The paper machine may also be equipped with a calendering unit. In the calendering unit, the dried sheet can be subjected to calendering treatment, in which a pair of calender rolls sandwich and press the sheet from above and below, as needed. This compresses the sheets 11L and 12L, adjusting and uniforming the paper thickness and smoothing the surface. Calendering suppresses protrusions (raising) caused by fibers on the sheet surface, generally reducing softness. The calendering unit may be provided separately from the paper machine, and calendering may be performed in any manufacturing process after the raw roll manufacturing process. Calendering may be performed in multiple stages.

[0084] (Toilet roll manufacturing) Toilet rolls are manufactured using raw rolls 11R, 12R. The raw rolls 11R, 12R may be manufactured according to the raw roll manufacturing method described above, or manufactured raw rolls 11R, 12R may be obtained by purchase or the like; there are no particular limitations on the method for preparing the raw rolls 11R, 12R. Figure 7 is a schematic diagram showing an example of manufacturing equipment applicable to the manufacture of toilet rolls according to an embodiment of the present invention. Figure 7 is for illustrative purposes only and does not limit the present invention.

[0085] The raw web roll 11R and the raw web roll 12R are rotatably attached to the raw web roll stand 70, and are driven to rotate by a raw paper sheet feeding device (not shown) to feed out the sheets 11L and 12L. The sheets 11L and 12L may be of the same or different paper quality.

[0086] The sheets 11L and 12L unwound from the raw web rolls 11R and 12R are transported to an embossing unit 76 located downstream of the raw web roll stand 70. Downstream of the embossing unit 76, a winding unit 77 and an end processing unit 78 are further arranged in this order.

[0087] The embossing unit 76 is, in short, a unit that embosses the sheets 11L and 12L to form embossed sheets.

[0088] The embossing section 76 includes two sets of embossing roll units 71 and 72 and one bonding embossing roll unit 75 .

[0089] Each of the embossing roll units 71 and 72 has an embossing roll and a backup roll. The embossing roll of the embossing roll unit 71 is rotatable, and has an outer peripheral surface formed with concave and convex portions corresponding to the embossing pattern of the first embossed portion 11a of the sheet 11 shown in Fig. 1. Similarly, the embossing roll of the embossing roll unit 72 is rotatable, and has an outer peripheral surface formed with concave and convex portions corresponding to the embossing pattern of the second embossed portion (not shown) of the sheet 12 shown in Fig. 1.

[0090] Two rotatable guide rollers 73 and 74 are provided upstream of the embossing roll units 71 and 72, respectively, to guide the sheets 11L and 12L in correspondence with the embossing roll units 71 and 72, respectively.

[0091] In the manufacturing apparatus shown in Figure 7, the embossing section 76 is configured to be able to selectively perform (i) single embossing, (ii) double embossing, or (iii) no embossing depending on the paper path of the sheets 11L and 12L and whether or not pressure is applied by the embossing roll units 71 and 72.

[0092] (i) Single embossing FIG. 7 shows an example of the path of the sheets 11L and 12L when single embossing is performed. When single embossing is performed, the sheets 11L and 12L fed from the raw rolls 11R and 12R are both wrapped around a guide roller 73, overlapped, and guided toward the embossing roll unit 71. The embossing roll unit 71 includes an embossing roll and a backup roll arranged movably in the direction facing the embossing roll, and the overlapped sheets 11L and 12L are inserted between them. The backup roll is pressed against the outer peripheral surface of the embossing roll with a predetermined pressure, resulting in a common embossing process being performed on the sheets 11L and 12L passing between them. In this case, sheets of the same or different paper quality can be used as the sheets 11L and 12L. As a modified example, a single raw roll on which the sheets 11L and 12L are superimposed and wound up in advance may be used, and the sheets 11L and 12L may be unwound from the raw roll in a superimposed state and wound around the guide roller 73.

[0093] (ii) Double embossing When double embossing is performed, the sheet 11L unwound from the raw web roll 11R is wound around a guide roller 73 and guided toward the embossing roll unit 71, where it is inserted between the embossing roll and backup roll of the embossing roll unit 71. Similarly, the sheet 12L unwound from the raw web roll 12R is wound around a guide roller 74 and guided toward the embossing roll unit 72. The embossing roll unit 72 includes an embossing roll and a backup roll that is arranged to be movable in a direction facing the embossing roll, and the sheet 12L is inserted between them. Each backup roll is pressed against the outer peripheral surface of the corresponding embossing roll with a predetermined pressure, and the sheets 11L and 12L passing between them are embossed. In this case, sheets of the same or different paper quality can be used.

[0094] (iii) No embossing In the case of no-embossing, in which the entire surface of the sheets 11L and 12L is not embossed, the sheets 11L and 12L are passed through the same paper passage path as that used in double embossing or single embossing, but the backup roll is not pressed against the outer peripheral surface of the embossing roll in the embossing roll unit. In this case, sheets of different paper quality are used for the sheets 11L and 12L.

[0095] (Embossing for joining) A bonding embossing roll unit 75 is disposed downstream of the embossing roll units 71 and 72. The bonding embossing roll unit 75 has an embossing wheel and a backing roll that face each other. The backing roll is rotatable so as to rotate synchronously with the embossing rolls of the embossing roll units 71 and 72, and an embossing pattern corresponding to the bonding embossing portion is formed on the outer circumferential surfaces of the embossing wheel and the backing roll.

[0096] After passing through the embossing roll unit, sheets 11L and 12L are passed, overlapped with each other, between the embossing wheel and backing roll of the bonding embossing roll unit 75 and are wound around the backing roll. At this time, if necessary, the embossing wheel is pressed against the rotating backing roll with a predetermined pressure by a fluid pressure cylinder, thereby subjecting the laminate of sheets 11L and 12L to bonding embossing and providing bonding embossed portions to prevent peeling.

[0097] In an embodiment of the present invention, the joining embossed portion is provided for the purpose of preventing separation of two sheets in a two-ply toilet paper.

[0098] In this example, at least the uneven portions of the embossing rolls of the embossing roll units 71 and 72 and the bonding embossing roll unit 75 are formed of metal, but the surface portion of the backup roll is formed of a hard rubber-like elastic material such as elastically deformable hard synthetic rubber.

[0099] By performing embossing using a male (convex) embossing steel roll and a plain rubber roll, it is possible to make the texture of one surface of the embossed sheet significantly different from that of the other surface. For example, in the embossed convex portions formed by the embossing steel roll, the nap on the sheet surface based on the constituent fibers of the sheet is crushed by contact with the plain rubber roll, reducing softness and increasing smoothness.

[0100] The wide toilet paper 13L formed by the sheets 11L and 12L stacked in the embossing section 76 is sent to a winding section 77 disposed downstream thereof.

[0101] In the winding section 77, the tip of the toilet paper 13L delivered from the embossing section 76 is wound around a wide (i.e., axially long) paper tube 14L, which serves as the core, via adhesive (pickup glue).

[0102] The toilet paper 13L is wound up to a predetermined length around the paper tube 14L to form a roll 86 that will become a wide toilet roll 10L (i.e., a large dimension in the CD direction), and the end of the toilet paper 13L is cut off by cutting means (not shown). The resulting roll 86 is sent to the end processing section 78.

[0103] The end processing section 78 glues the end of the end of the roll 86 sent out from the winding section 77 to the surface (outer circumferential surface of the roll) of the roll 86 with adhesive (tail seal glue) to form a wide toilet roll 10L, preventing the wide toilet roll 10L from unwinding.

[0104] Note that, prior to cutting the toilet paper 13L at predetermined lengths in the winding section 77, tearing perforations that traverse the width of the toilet paper 13L may be formed 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. However, forming such tearing perforations is optional and not essential in embodiments of the present invention.

[0105] The wide toilet roll 10L is then transported from the end processing section 78 to a cutting section (not shown) where it is cut into individual toilet rolls 10 at a predetermined width according to product specifications, etc.

[0106] Meanwhile, in the winding section 77, the tip end of the toilet paper 13L (i.e., the end of the toilet paper 13L on the original roll 11R, 12R side) produced by cutting the toilet paper 13L at predetermined lengths is wound around a new long axial core arranged in the winding section 77 via adhesive, and the toilet paper 13L is again wound around the long axial core by a predetermined length.

[0107] The formed log of wide toilet roll 10L is then subjected to a cutting process by cutting means (not shown) and cut to a predetermined width (product width of toilet roll), thereby producing toilet roll 10.

[0108] The above-described manufacturing method and manufacturing device are just one example. For example, instead of forming roll 86 (i.e., the log used to form toilet roll 10) that will become toilet roll 10L in winding section 77, a longer roll may be formed, and this may be loaded as a secondary roll into another device with a winding function, such as a winder, and toilet rolls may be manufactured through a process of forming a log of a predetermined length.

[0109] Furthermore, the term "embossing for joining" may include joining by a processing form such as stamping, which uses a stamping roll or the like to deform the workpiece, in addition to using the embossing roll described above.

[0110] (Action and effect) According to the two-ply toilet roll 10 having the joining embossment according to this embodiment, the basis weight per sheet of the two sheets 11 and 12 constituting the two-ply toilet paper 13 is 11 g / m 2 More than 16g / m 2 or less, which ensures appropriate strength and water absorption, and the roll length of the toilet roll 10 is 33 m or more and 100 m or less, and the roll diameter is 100 mm or more and 134 mm, which means that the length of toilet paper 13 per roll is long, making it possible to save space when carrying and storing.

[0111] In addition, the TS750 value obtained by the tissue softness measuring device TSA 20 for the two-ply toilet paper 13 is 12 dBV on the TS750 outer surface. 2 rms over 30dBV 2 rms or less, and the outer surface (the surface on the outside of the roll) of the toilet paper 13 has an excellent texture (smoothness). Also, at this time, the difference D between the TS750 inner surface and the TS750 outer surface is 0 dBV. 2 rms (i.e., the TS750 inner surface is larger than the TS750 outer surface), and the inner surface of the toilet paper 13 (the surface that faces the inside of the roll) has a moderate smoothness (roughness). In other words, because the inner surface of the toilet paper 13 is rougher than the outer surface, the inner sheet and the outer sheet of the two-ply toilet paper 13 do not slide easily, which prevents the two-ply toilet paper 13 from peeling apart when the toilet paper 13 is pulled out from the toilet roll 10, and as a result, prevents the toilet roll 10 from rewinding.

[0112] Furthermore, in this embodiment, the toilet paper 13 has a first bonding embossed portion 11e for defining a bonding area where the two sheets 11, 12 constituting the two plies are in close contact with each other, and a second bonding embossed portion 12e for defining a bonding area where the two sheets 11, 12 are in close contact with each other together with the first bonding embossed portion 11e and integrally bonding the two sheets 11, 12 together with the first bonding embossed portion 11e. By bonding them together using the bonding embossed portions in this way, the two sheets 11, 12 of the toilet paper are prevented from peeling off when the toilet roll is in use, and the toilet roll can be prevented from rewinding.

[0113] Therefore, according to this embodiment, the two-ply toilet roll 10 can save space when carrying and storing, and can also improve the texture (smoothness) of the toilet paper 13 while preventing the toilet roll 10 from rewinding.

[0114] In an embodiment of the present invention, the TS750 values ​​of both sides of the toilet paper 13 (TS750 outer surface and TS750 inner surface) can be controlled by, for example, the single embossing pattern, the size of the embossed convex portion (diameter, etc., mm), the density of the embossed convex portion (pieces / cm 2 ), height of embossed convex part (mm), embossing pressure (gf / cm 2 ) can be achieved by appropriately setting the thickness and density of the paper after the embossing pressure is applied.

[0115] In addition, the TS750 value (TS750 outer surface and TS750 inner surface) of the toilet paper 13 is affected by, for example, the creep processing and / or calendar processing when making the sheets 11L and 12L, and the various conditions of the calendar processing when forming the toilet paper 13L (including whether or not processing is performed).

[0116] (Second embodiment) Next, a second embodiment of the present invention will be described. Unless otherwise specified, the configurations applicable to the above-described embodiments are applicable to this embodiment.

[0117] In the toilet roll according to the second embodiment, each of the sheets constituting the toilet paper contains wood pulp, and when the content of wood pulp in the sheet is W and the content of recycled paper pulp in the sheet is R, the recycled paper pulp content in the sheet calculated by the formula R÷(W+R)×100 is equal to or greater than 0% by mass and less than 40% by mass.

[0118] As explained in the first embodiment, in the embodiment of the present invention, the pulp component of the sheet may be one type alone or two or more types may be mixed together. These pulp components have a significant effect on the quality of the toilet paper, so they are appropriately blended in predetermined types and blending ratios according to the required quality.

[0119] Wood pulp, which is virgin pulp produced from wood, can provide sheets with strength, flexibility, uniformity, good texture, softness, etc., and is also excellent in terms of whiteness and hygiene.

[0120] On the other hand, waste paper pulp, which is pulp produced by recycling waste paper, is effective in reducing waste, conserving the energy resources needed to incinerate waste, curbing CO2 emissions from incineration, and conserving forest resources needed to produce wood pulp.

[0121] Therefore, this embodiment mainly uses wood pulp as the pulp component, and also includes an embodiment in which wood pulp and recycled paper pulp are used in combination from the viewpoint of reducing waste and preserving resources.

[0122] Waste paper pulp is produced through a series of necessary processes, including disintegrating the raw material waste paper (pulp made from paper) in water, a rough screening process to remove large foreign objects, a deinking process to peel off and separate the ink adhering to the pulp, a screening process to remove small foreign objects, and a pulp bleaching process. These manufacturing processes utilize mechanical force, gravity, surfactants, chemicals such as bleach, and heat, and, with an emphasis on safety and hygiene, sterilization and disinfection are repeated as necessary.

[0123] In this way, recycled paper pulp loses strength due to physical and chemical damage and wetting and drying during the manufacturing process, and sheets made from such recycled paper pulp generally have less strength and softness than sheets made from wood pulp.

[0124] Therefore, from the viewpoint of the strength and softness of the sheet to be manufactured, and in turn the toilet paper, there is a suitable upper limit to the blending ratio of recycled paper pulp (the content of recycled paper pulp in the sheet).

[0125] Specifically, in this embodiment, the recycled paper pulp content in the sheet is calculated by the formula R÷(W+R)×100, where W is the wood pulp content in the sheet and R is the recycled paper pulp content in the sheet. The recycled paper pulp content in the sheet is 0% by mass or more and less than 40% by mass.

[0126] When the recycled paper pulp content in the sheet is 0% by mass or more and less than 40% by mass, the sheet can be provided with appropriate strength and softness. When the recycled paper pulp content is 40% by mass or more, the softness of the sheet decreases, and the toilet paper's usability decreases.

[0127] As for recycled paper, so-called milk carton pulp, which is made from paper cartons (milk cartons), is preferably used because it is mainly made from high-strength softwood pulp, has little printing, and has high whiteness, resulting in sheets that are strong and have high whiteness.

[0128] (Action and effect) In the second embodiment, the sheet contains wood pulp and recycled paper pulp in a predetermined blend ratio to meet the required quality, thereby contributing to waste reduction and resource conservation while ensuring the desired sheet strength and softness.

[0129] In manufacturing a toilet roll according to an embodiment of the present invention, in order to form toilet paper, (1) An embodiment including a no-embossing step in which two sheets of different paper quality are used and the two sheets are overlapped without embossing the entire surface of each of the two sheets; (2) An embodiment including a double embossing process in which two sheets of the same or different paper quality are used, and the entire surface of each of the two sheets is embossed under different embossing conditions, and then the two sheets are superimposed. (3) An embodiment including a single embossing step in which two sheets of the same or different paper quality are used, and the two sheets are stacked together and embossed all over the two sheets. I have explained that there is.

[0130] Here, the TS750 value is the intensity (amplitude) of the first maximum peak P1 of a single spectrum based on the vertical vibration of the sample, and the amplitude (intensity) depends on the height of the structure. Therefore, as a method for adjusting the values ​​of the TS750 inner surface and the TS750 outer surface to the desired relationship, Regarding embodiment (1), for example, by varying the conditions (including whether or not processing is performed) of the creep processing and / or calendar processing when making the sheets 11L and 12L, and the calendar processing when forming the toilet paper 13L, the TS750 values ​​of both sides of the toilet paper 13 (TS750 outer surface and TS750 inner surface) can be controlled.

[0131] Regarding embodiment (2), the TS value of each sheet can be adjusted by varying the embossing conditions applied to each of the two sheets 11 and 12 that make up the toilet paper 13. For example, the TS value of each sheet can be adjusted by changing the embossing pattern formed by embossing, the size of the embossed convex portions (diameter, etc., mm), the density of the embossed convex portions (number of convex portions / cm 2 ), height of embossed convex part (mm), embossing pressure (gf / cm 2 ), the TS7 value of both sides of the toilet paper 13 can be controlled by appropriately setting the paper thickness and density after applying the embossing pressure, etc., to vary the surface texture of each sheet.

[0132] Regarding the embodiment (3), for example, the embossed pattern formed by embossing, the size of the embossed convex portions (diameter, etc., mm), the density of the embossed convex portions (pieces / cm 2 ), the height (mm) of the embossed convex portions, etc. In addition, the relationship between the TS7 values ​​on both sides of the toilet paper 13 can be controlled to be different by selecting the type of embossing roll used for embossing (for example, whether a male (convex) embossing roll and a female (concave) embossing roll are used, and in that case, whether they are matched or not, or whether a male (convex) embossing steel roll and a plain rubber roll are used), changing the hardness of the embossing roll, the embossing pressure, etc. [Example]

[0133] Using the manufacturing device shown in Figure 7, toilet rolls were manufactured through the following manufacturing steps. (a) A papermaking slurry (stock) with a pulp composition of 30% by mass of softwood bleached kraft pulp (NBKP):70% by mass of hardwood bleached kraft pulp (LBKP) was used to produce multiple sheets, some of which were different in at least one of the following: sheet basis weight, paper thickness, creping conditions, and calendering conditions. (b) Examples 1, 2, 4, 5, 8, and 10 and Comparative Examples 1 to 5 were subjected to single embossing. That is, two of the multiple sheets produced were stacked together to form a laminated sheet, and the entire surface of the laminated sheet was subjected to single embossing, with one side embossed concavely and the other side embossed convexly. The pressure and / or speed used for embossing varied depending on the sample. (c) Examples 3, 6, 7, 9, and 11 were double-embossed. That is, two of the sheets produced were embossed on the entire surface, with one side embossed concavely and the other embossed convexly, and then the two sheets were stacked together so that the concave embossed surface was on the outer side to form a laminated sheet. The pressure and / or speed used for embossing varied depending on the sample. (d) Next, for the examples, bonding embossing was applied to both side edges in the width direction (CD) of the laminate sheet so that the bonding embossments extended along the longitudinal direction (MD). (e) The starting end of the laminated sheet was pressed against a paper tube coated with pick-up glue, adhesively fixed, and wound around the paper tube in a roll with the embossed recesses facing outwards. (f) When the wound length reached a predetermined length, the end of the wound laminate sheet was cut off to obtain a wide toilet roll. (g) A wide toilet roll was cut to a specified width, and a toilet roll was produced in which embossed two-ply toilet paper was wound into a roll so that the outer surface of the roll had embossed recesses.

[0134] The following measurements and evaluations were carried out on the toilet rolls of Examples 1 to 11 and Comparative Examples 1 to 5. The measurements were carried out by conditioning the samples in an environment conforming to Japanese Industrial Standard JIS P8111 (temperature 23±1°C, humidity 50±2% RH).

[0135] <Measurement> [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 beginning was measured. Measurements were taken in 0.5 m increments and fractions were rounded down.

[0136] [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.

[0137] [Core diameter of paper tube [mm]] The outer diameter of the paper tube of the produced toilet roll was measured with a vernier caliper and rounded off to the nearest whole number.

[0138] [winding density [m / cm 2 ] It was calculated according to the following formulas (I) and (II).

[0139] (Winding density) = (winding length x number of plies) ÷ (cross-sectional area of ​​toilet roll) (Equation I) (Cross-sectional area) = (Toilet roll diameter DR ÷ 2) 2 ×3.14-(core diameter DC÷2) 2 ×3.14 (Formula II)

[0140] [Basis weight (per base paper sheet) [g / m 2 ] The basis weight of the base paper sheet used in the production of toilet rolls was measured in accordance with Japanese Industrial Standards JIS P8124.

[0141] [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 in accordance with Japanese Industrial Standard JIS P8124, and divided by 2, the number of plies, to determine 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 10 cm x 10 cm piece with the two sheets still stacked, and the weight of the cut two-ply toilet paper was measured, and the weight was multiplied by 0.01 m of the cut area of ​​the two-ply toilet paper. 2 The basis weight of the two-ply toilet paper was measured by dividing by 1 / 2, the number of plies, to determine the basis weight per sheet.

[0142] [Paper thickness (per roll of 2-ply toilet paper) [μm]] Toilet paper was pulled out from the toilet roll, and the thickness of the two-ply toilet paper (two sheets per set) was determined in accordance with the International Organization for Standardization standard ISO 12625-3.

[0143] (TS750 exterior and interior) Using the above-mentioned tissue softness measuring device TSA, the TS750 value measurement procedure was followed to obtain the TS750 outer surface, with the outer surface of the toilet paper (the surface that will be on the outside of the toilet roll) as the measurement surface, and the TS750 inner surface, with the inner surface of the toilet paper (the surface that will be on the inside of the toilet roll) as the measurement surface.

[0144] [Difference D (TS750 inner surface - TS750 outer surface)] The difference D between the TS750 inner surface and the TS750 outer surface (TS750 inner surface - TS750 outer surface) was calculated by subtracting the value of the TS750 outer surface from the value of the TS750 inner surface.

[0145] [Ratio R (TS750 inner surface / TS750 outer surface)] The ratio R of the TS750 inner surface to the TS750 outer surface (TS750 inner surface / TS750 outer surface) was calculated by dividing the value of the TS750 inner surface by the value of the TS750 outer surface.

[0146] <Evaluation> A sensory evaluation was carried out for the following items, and the results were indicated by symbols (◎: excellent, ◯: good, △: acceptable, ×: unacceptable). The sensory evaluation was a relative evaluation of samples with the same toilet roll roll length.

[0147] [Texture of the outer surface of toilet paper] The smoother the outer surface of the toilet paper felt, the better the texture was rated (◎).

[0148] [Comeback] Referring to Figure 8(a), the toilet roll was rotatably supported on a holder (not shown), and as shown in Figure 8(c), the edge of the outer sheet of the two sheets that make up the two plies of toilet paper was held with the fingers and unwound while pointing upward. When the edge of the sheet reached the top of the toilet roll in the vertical direction, the state in which the inner sheet of the toilet roll followed the outer sheet and was pulled out was rated as excellent (◎); when the inner sheet did not follow the outer sheet from the beginning and was not unwound, it was rated as poor (×); and when the inner sheet separated from the outer sheet and fell off partway through, it was rated according to the degree of unwinding, from best to worst as good (◯), fair (△), or poor (×).

[0149] Tables 1 to 3 show the test results.

[0150] [Table 1]

[0151] [Table 2]

[0152] [Table 3]

[0153] As shown in Tables 1 to 3, in all of Examples 1 to 11 (all Examples) and Comparative Examples 1 to 5 (all Comparative Examples), the toilet roll had a roll length of 33 m or more and 100 m or less, and a roll diameter of 100 mm or more and 134 mm or less.The roll diameter was large enough to be rotatably stored in a typical toilet roll holder, and the roll length was long, allowing for space-saving transport and storage of the roll.

[0154] In addition, the basis weight per sheet constituting the two-ply toilet paper of Examples 1 to 11 is 11 g / m 2 More than 16g / m 2 This was a size that ensured adequate strength and water absorption.

[0155] In Examples 1 to 11, a bonding embossment (edge ​​embossment) is provided, and the outer surface of the TS750 is 12 dBV. 2 rms over 30dBV 2 The texture (smoothness) of the outer surface of the toilet paper was good or excellent, and the rewinding of the toilet roll was rated as excellent or good.

[0156] In contrast, no joining embossment (edge ​​embossment) was provided in Comparative Examples 1 to 5. The toilet rolls of Comparative Examples 1 to 5 were evaluated as poor in terms of rewinding.

[0157] In addition, in Comparative Example 1, the outer surface of the TS750 is 31.5 dBV 2 rms, which was greater than the upper limit of the range for the TS750 outer surface of the present invention, and the feel (smoothness) of the outer surface of the toilet paper was inferior.

[0158] Comparative Example 3 has a basis weight of 16.9 g / m 2 This was above the upper limit of the basis weight range of the present invention. [Explanation of symbols]

[0159] 10,100 toilet rolls 11, 12, 110, 120 sheets 11e First joining embossed portion 12e Second joining embossed portion 13e Embossed section 11R, 12R raw roll 13,130 toilet paper 14,140 Paper tube 16,17 Embossing roll for bonding 20 Tissue Softness Measurement Device TSA 21 Sample stage 23 Samples 24 Sample fixing ring 25 bladed rotor 25a blade 25b motor 70 Raw roll stand 71 Embossing roll unit 73 Guide Roller 74 Guide Roller 76 Embossed section 77 Winding section DR Toilet roll diameter DC Core diameter P1 Peak TS7 value P2 Peak TS750 value

Claims

1. A toilet roll in which two sheets of toilet paper are overlapped and wound into a roll, The toilet roll has a roll length of 33 m or more and 100 m or less, and a roll diameter of 100 mm or more and 134 mm or less, The basis weight of each sheet is 11 g / m 2 16g / m or more 2 is as follows: Using the tissue softness measuring device TSA, the toilet paper sample was placed on a sample stage with the outer surface of the toilet roll facing up, and a bladed rotor was pressed from above with a pressing pressure of 100 mN, and then rotated at a rotation speed of 2.0 per second. The vibration of the sample stage was measured with a vibration sensor, and the intensity of the first maximum peak of the spectrum seen from the low frequency side (TS750 value) was obtained. The TS750 outer surface was 12 dBV. 2 rms or more 30dBV 2 is less than or equal to rms, Using the tissue softness measuring device TSA, the toilet paper sample is placed on the sample stage with the inner side of the toilet roll facing up, and the bladed rotor is pressed from above with a pressing pressure of 100 mN, and then rotated at a rotation speed of 2.0 per second. When the vibration of the sample stage is measured with a vibration sensor, the intensity of the first maximum peak (TS750 value) of the spectrum viewed from the low frequency side is obtained, and the TS750 inner surface is greater than the TS750 outer surface. The toilet paper is a first bonding embossment for defining a bonding area where the two sheets are in close contact with each other; a second bonding embossed portion that, together with the first bonding embossed portion, defines a bonding area where the two sheets are in close contact with each other, and that bonds the two sheets together with the first bonding embossed portion; and The toilet roll is a double-embossed product in which a repeating pattern of embossment is formed across the entire surface of the two sheets before the two sheets are superimposed.

2. The toilet roll according to claim 1, wherein the sheet contains wood pulp, and the recycled paper pulp content in the sheet is calculated by the formula R ÷ (W + R) × 100, where W is the wood pulp content in the sheet and R is the recycled paper pulp content in the sheet, and the recycled paper pulp content in the sheet is equal to or greater than 0% by mass and less than 40% by mass.

3. A toilet roll in which two sheets of toilet paper are overlapped and wound into a roll, The toilet roll has a roll length of 33 m or more and 100 m or less, and a roll diameter of 100 mm or more and 134 mm or less, The basis weight of each sheet is 11 g / m 2 16g / m or more 2 is as follows: Using the tissue softness measuring device TSA, the toilet paper sample was placed on a sample stage with the outer surface of the toilet roll facing up, and a bladed rotor was pressed from above with a pressing pressure of 100 mN, and then rotated at a rotation speed of 2.0 per second. The vibration of the sample stage was measured with a vibration sensor, and the intensity of the first maximum peak of the spectrum seen from the low frequency side (TS750 value) was obtained. The TS750 outer surface was 12 dBV. 2 rms or more 30dBV 2 is less than or equal to rms, Using the tissue softness measuring device TSA, the toilet paper sample is placed on the sample stage with the inner side of the toilet roll facing up, and the bladed rotor is pressed from above with a pressing pressure of 100 mN, and then rotated at a rotation speed of 2.0 per second. When the vibration of the sample stage is measured with a vibration sensor, the intensity of the first maximum peak (TS750 value) of the spectrum viewed from the low frequency side is obtained, and the TS750 inner surface is greater than the TS750 outer surface. The toilet paper is a first bonding embossment for defining a bonding area where the two sheets are in close contact with each other; a second bonding embossed portion that, together with the first bonding embossed portion, defines a bonding area where the two sheets are in close contact with each other, and that bonds the two sheets together with the first bonding embossed portion; A method for producing toilet paper comprising: The method includes a forming step of forming the two-ply toilet paper by overlapping the two sheets, and a winding step of winding the formed two-ply toilet paper into a roll with a predetermined length and a predetermined winding diameter, The forming step is performed to form the TS750 outer surface at 12 dBV. 2 rms or more 30dBV 2 rms or less, and the TS750 inner surface is larger than the TS750 outer surface. a first step of using sheets of the same or different paper quality as the two sheets, embossing the entire surface of each of the two sheets under different embossing conditions, and then overlapping the two sheets to perform double embossing; a second step of performing a bonding embossing process after the first step to form a first bonding embossed portion for defining a bonding area where the two sheets will adhere to each other, and a second bonding embossed portion for defining a bonding area where the two sheets will adhere to each other together with the first bonding embossed portion and for integrally bonding the two sheets together with the first bonding embossed portion; A method for producing toilet rolls, comprising:

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