Toilet roll
The toilet roll design addresses the issue of recess collapse and inversion in double-embossed toilet paper by using specific embossing patterns and orientations, ensuring smoothness and fluffiness in longer lengths.
Patent Information
- Application Number
- JP2024058298
- Authority / Receiving Office
- JP · JP
- Patent Type
- Applications
- Current Assignee / Owner
- Filing Date
- 2024-03-29
- Publication Date
- 2025-10-10
AI Technical Summary
Toilet rolls with double-embossed toilet paper experience issues such as recesses being crushed or inverted into convex shapes, leading to reduced smoothness and fluffiness, especially as roll length increases, resulting in decreased design quality.
A toilet roll design featuring two-ply double-embossed toilet paper with specific embossing patterns and orientations, where the first sheet is on the outer surface and the second sheet is on the inner surface, with recesses and valley grooves arranged to avoid alignment with the paper flow direction, and controlled thickness and basis weight to prevent collapse and inversion.
The design improves the smoothness and fluffiness of toilet rolls, reducing the occurrence of recess collapse and convex inversion, maintaining high quality even in longer lengths.
Smart Images
Figure 2025154974000001_ABST
Abstract
Description
[Technical Field]
[0001] The present invention relates to a toilet roll in which a strip of toilet paper is wound into a roll. [Background technology]
[0002] Toilet rolls are available in a variety of roll lengths to suit consumer preferences. For example, there are known products such as regular or standard products, in which two-ply toilet paper is wound to a length of approximately 25 to 30 m; products that are 1.5 times the length of the regular product, at approximately 37.5 to 45 m; products that are twice the length of the regular product, at approximately 50 to 60 m; and products that are 3 to 3.2 times the length, at approximately 75 to 90 m, or 3.2 times the length (see Patent Document 1 below). Products with roll lengths exceeding 1.5 times the length are sometimes referred to as long products.
[0003] On the other hand, some toilet rolls are wrapped with toilet paper that has been embossed to create a textured surface. Known types of toilet paper texture, known in relation to the embossing process, are single embossed and double embossed.
[0004] Generally, single embossing refers to a mode in which recesses are formed on one side and convex portions corresponding to the recesses are formed on the other side by embossing, while double embossing refers to a mode in which multiple sheets are stacked together, each sheet having recesses formed on one side and convex portions corresponding to the recesses on the other side by embossing (see Patent Documents 1 to 4 below).
[0005] Double-embossed toilet paper is usually stacked so that the recessed side of each sheet faces outward, and is superior to single-embossed toilet paper in that both the front and back are smooth, there is little difference in feel between the front and back, and the gaps formed between the sheets give it a fluffy, soft feel (see Patent Document 4 below). [Prior art documents] [Patent documents]
[0006] [Patent Document 1] Japanese Patent Publication No. 2020-179882 [Patent Document 2] Japanese Patent Publication No. 2022-066267 [Patent Document 3] Japanese Patent Publication No. 2023-065593 [Patent Document 4] Patent Publication No. 2021-053249 Summary of the Invention [Problem to be solved by the invention]
[0007] However, it has been found that in toilet rolls wound with double-embossed toilet paper, particularly as the roll length increases, many toilet rolls have areas where the recesses are crushed or collapsed, or where the recesses are inverted into a convex shape.
[0008] It was found that the surface becomes less smooth and less fluffy in these areas. Furthermore, it was also found that the formation of such areas can cause differences in the clarity of the recesses and the occurrence of vertical wrinkles along the winding direction, which can reduce the overall design quality.
[0009] In particular, the toilet roll disclosed in Patent Document 4 has an embossed pattern in which recesses are arranged at predetermined intervals along the winding direction and valley grooves are formed to connect the four corners of the recesses. The valley grooves make the toilet paper more flexible, making it suitable for increasing the winding length of double-embossed toilet paper. However, even with an embossed pattern in which the recesses are connected by valley grooves, the above-mentioned collapse of the recesses occurs.
[0010] Therefore, the main object of the present invention is to improve the collapse and crumbling of recesses and the formation of areas where recesses are inverted into convex shapes in toilet rolls wrapped with double-embossed toilet paper, and to provide toilet rolls that are smooth and fluffy and soft. [Means for solving the problem]
[0011] The first means for solving the above problem is: A toilet roll in which a two-ply double-embossed toilet paper is wound around a paper tube, the toilet roll comprising a first sheet located on the outer surface of the roll and having embossed recesses and protrusions corresponding to the recesses, and a second sheet located on the inner surface of the roll and having embossed recesses and protrusions corresponding to the recesses, laminated together so that the protrusion-forming surfaces face each other, The toilet roll is The winding length is 45 m or more, the roll diameter is 110 to 130 mm, and the winding density is 0.75 to 1.6, The toilet paper is Basis weight per ply: 11.0 to 18.0 g / m 2 The thickness of the two plies is 125 to 205 μm, and the thickness of the first sheet is 65 to 120 μm; The embossed pattern of at least the first sheet is The toilet paper has recesses arranged in a straight line at a predetermined interval and valley grooves that are shallower than the recesses and extend in all directions from the recesses to connect the recesses, and the direction in which the recesses are arranged and the extension direction of the valley grooves do not coincide with the direction in which the toilet paper flows. This toilet roll is characterized by the following:
[0012] The second aspect is the toilet roll according to the first aspect, in which the direction in which the recesses are arranged is at an angle of between ±10 degrees and 45 degrees relative to the direction of flow of the toilet paper.
[0013] A third aspect is the toilet roll according to the first or second aspect, wherein the shape of the recesses in the first sheet is a square or a four-pointed star, and the valley grooves extend from the four vertices of the recesses.
[0014] A fourth aspect is the toilet roll according to the third aspect, wherein the distance between the recesses of the first sheet is 5.05 to 5.35 mm.
[0015] A fifth aspect is the toilet roll according to the third or fourth aspect, wherein the width of the recessed portion of the first sheet is 1.15 to 1.31 mm. [Effects of the Invention]
[0016] According to the present invention, collapse and crumbling of recesses and formation of areas where recesses are inverted into convex shapes in a toilet roll wound with double-embossed toilet paper are improved, and a toilet roll with excellent smoothness and fluffy softness is provided. [Brief explanation of the drawings]
[0017] [Figure 1] FIG. 1 is a perspective view illustrating a toilet roll according to the present invention. [Figure 2] FIG. 3 is a plan view illustrating an embossing pattern of the first sheet according to the present invention. [Figure 3] FIG. 10 is a plan view for shaping the recessed portion according to the present invention. [Figure 4] FIG. 10 is a plan view illustrating another embossing pattern of the first sheet according to the present invention. [Figure 5] FIG. 10 is a plan view illustrating another embossing pattern of the first sheet according to the present invention. [Figure 6] FIG. 10 is a plan view illustrating yet another embossing pattern of the first sheet according to the present invention. [Figure 7] 3A and 3B are schematic cross-sectional views taken along lines II, II-II, and III-III in FIG. 2. [Figure 8] FIG. 10 is a plan view illustrating measurement points of a cross-sectional curve of a recess. [Figure 9] 9A and 9B are diagrams showing examples of undulation curves at positions A1-A1 and A2-A2 in FIG. 8. [Figure 10]9A and 9B are diagrams showing examples of undulation curves at positions B1-B1 and B2-B2 in FIG. 8. [Figure 11] FIG. 4 is a plan view illustrating an embossing pattern of a second sheet according to the present invention. [Figure 12] FIG. 10 is a plan view illustrating overlapping of a recessed portion of a first sheet and a recessed portion of a second sheet according to the present invention. [Figure 13] FIG. 10 is a diagram illustrating toilet paper according to a comparative example. DETAILED DESCRIPTION OF THE INVENTION
[0018] Next, embodiments of the present invention will be described in detail below with reference to FIGS. As shown in Figure 1, the toilet roll 1 according to this embodiment is a cylindrical shape in which two-ply water-decomposable toilet paper 10, consisting of a first sheet 11 and a second sheet 12 laminated together, is wound around a paper tube 20, also known as a tube core. In the toilet roll 1 of this embodiment, the toilet paper 10 is wound so that the first sheet 11 is on the outer surface of the roll and the second sheet 12 is on the inner surface of the roll.
[0019] While the roll length of two-ply toilet rolls, known as ordinary or standard products, is approximately 25 to 30 m, the roll length of the toilet roll 1 according to this embodiment is 45 m or more and 2-ply, and can be wound in a range of so-called long products, such as 1.5x, 2x, 3x, and 3.2x rolls. In terms of the effects of the present invention, the upper limit of the roll length is preferably 125 m, and is suitable for long products with a roll length of 4 to 4.2 times the roll length of products known as ordinary or standard products.
[0020] The roll diameter L2 (diameter) of the toilet roll 1 according to this embodiment is 110 to 130 mm, preferably 110 to 120 mm. Holders for setting toilet rolls are generally manufactured based on JIS P 4501, with a standard diameter of 120 mm. The toilet roll according to this embodiment has a roll diameter of 110 to 130 mm, and can be set in a standard holder. Furthermore, if the roll length is less than 110 mm, the toilet paper will be tightly wound, which will likely result in a deterioration in quality aspects such as feel to the touch. Here, the roll diameter L2 is a value measured using a diameter ruler manufactured by Muratec KDS Corporation or an equivalent device. The roll width L1 of the toilet roll 1 according to this embodiment is not limited, but is preferably 100 to 120 mm. The outer diameter L3 of the cardboard tube 20 is also not limited, but is preferably 36 to 42 mm.
[0021] The toilet paper 10 wound into the toilet roll 1 according to this embodiment is a two-ply toilet paper 10 in which a first sheet 11 and a second sheet 12 having embossed irregularities are laminated together. Furthermore, this toilet paper 10 is double-embossed toilet paper 10 in which each of the first sheet 11 and the second sheet 12 has an irregular shape with recesses 32 on one side and protrusions 31 corresponding to the recesses 32 on the other side, and the surfaces on which the protrusions are formed face each other, with the first sheet 11 located on the outer surface of the roll and the second sheet 12 located on the inner surface of the roll.
[0022] The toilet paper 10 of this embodiment is not a so-called laminate embossed type in which the outer sheet and the inner sheet are bonded together with an adhesive. That is, the first sheet 11 and the second sheet 12 are not bonded together with an adhesive or the like. In order to prevent ply separation, the first sheet 11 and the second sheet 12 are preferably integrated together by a ply compression bonding means called contact embossing, edge embossing, knurling, or the like.
[0023] In the toilet paper 10 of this embodiment, the basis weight of the first sheet 11 and the second sheet 12, i.e., the basis weight per ply, is 11.0 to 18.0 g / m 2 , preferably 12.0 to 17.0 g / m 2 If the basis weight of the first sheet 11 and the second sheet 12 is within this range, it is possible to obtain a sufficient softness and fluffy feel to the touch required for a long product, especially a long product wound at 1.5 times to 4.2 times, while improving the collapse and collapse of recesses and the formation of portions where the recesses are inverted into a convex shape. The basis weight can be adjusted, for example, by the fiber basis weight, crepe rate, etc. The difference in basis weight between the first sheet 11 and the second sheet 12 is set to 0.5 g / m2 so as to reduce the difference in tensile strength and stiffness between the outer and inner surfaces of the winding. 2 It is desirable that the basis weight is further adjusted by the winding length, and for 1.5 times winding and 2 times winding lengths, the basis weight is 16.0 to 17.0 g / m 2 , 3x winding, 3.2x winding, 4.2x winding length: 11.0~13.0g / m 2 It is desirable to do so.
[0024] The toilet paper 10 of this embodiment has a paper thickness of 120 to 205 μm, preferably 125 to 200 μm, for two plies. This paper thickness range allows for sufficient thickness and fluffiness required for long products wound at 1.5 to 4.2 times the roll diameter. The paper thickness can be adjusted, for example, by using or not using a calendaring process, the calendaring pressure, the embossing process, the crepe rate, etc.
[0025] In particular, in the toilet paper 10 of this embodiment, the thickness of the first sheet 11 is 65 to 120 μm. Because the first sheet 11 is located on the outer surface of the roll, it is the surface on which the design, etc., of the unevenness caused by the embossing is visible. At the same time, the outer surface of the roll is subjected to slightly stronger tension than the second sheet 12 on the inner surface of the roll during winding into a roll. In particular, long products are pulled more strongly during winding and after roll formation than regular products. In the toilet roll 1 of this embodiment, by setting the thickness of the first sheet 11 to 65 to 120 μm, in combination with other configurations of the present invention, such as the basis weight and the embossed pattern described below, crushing and crumbling of the recesses 32 and the formation of convex inverted portions of the recesses 32 are improved. The thickness of the first sheet 11 can also be adjusted, for example, by using or not using a calendaring treatment, the calendaring pressure, the embossing treatment, the crepe rate, etc. Furthermore, it is desirable to further adjust the paper thickness depending on the winding length, with a paper thickness of 100 to 120 μm for a 1.5x winding length, 95 to 110 μm for a 2x winding length, 70 to 90 μm for 3x and 3.2x winding lengths, and 65 to 75 μm for a 4.2x winding length.
[0026] The thickness of the second sheet 12 in the toilet paper 10 of this embodiment is not necessarily limited, but it is highly desirable that it be 65 to 120 μm, similar to that of the first sheet 11. Furthermore, it is desirable that the difference in thickness between the first sheet 11 and the second sheet 12 be within 20 μm. This eliminates the difference in the crushability of the convex portions in the thickness direction (also called the Z direction), making it less likely that the convex portions of the second sheet 12 will excessively affect the first sheet 11. The thickness of the second sheet 12 can also be adjusted, for example, by the presence or absence of calendering, the calendering pressure, the embossing, the crepe rate, etc.
[0027] The basis weight (basis weight) is measured in accordance with JIS P 8124. Paper thickness is measured by thoroughly conditioning the test piece under the conditions of JIS P 8111 (1998) (usually for about 8 hours) and then measuring it under the same conditions using a PEACOCK H-type dial thickness gauge (thickness measuring device) (manufactured by Ozaki Seisakusho). The thickness of two-ply paper is measured as is, while the first sheet 11 or second sheet 12 is measured after peeling each ply. Specifically, the measurement method involves confirming that there is no dust or dirt between the plunger and the measuring table, lowering the plunger onto the measuring table, adjusting the dial thickness gauge's scale to zero, then raising the plunger and placing the sample on the testing table. With the plunger open to 700 μm, the lever is lowered in one go and the gauge reading is taken. During measurement, the plunger is simply placed on the table, not pressed down. The plunger terminal is set so that the circular flat surface with a diameter of 10 mm is in contact with the paper surface perpendicularly, and the load when measuring the paper thickness is approximately 70 gf. The paper thickness is the average value obtained by measuring 10 times.
[0028] The specific volume of the toilet paper 10 in this embodiment is 5.5 to 7.5 cm for both the first sheet 11 and the second sheet 12. 2 The specific volume is calculated by dividing the paper thickness by the basis weight, and then calculating the volume cm per unit g. 3 Furthermore, it is desirable that the specific volume ratio (specific volume of the first sheet / specific volume of the second sheet) is 90 to 110%. The difference in paper quality between the first sheet 11 and the second sheet 12 is small, and the difference in feel, such as smoothness and softness, due to the difference in paper quality is small.
[0029] On the other hand, as shown in Figures 2 to 7, the toilet paper 10 of this embodiment characteristically has an embossed pattern on the first sheet 11 located at least on the outer surface of the roll, which includes linearly spaced recesses 32 and valley grooves 35 that are shallower than the recesses 32 and extend in all directions from the recesses 32 to connect the recesses 32. The first sheet 11 is located on the outer surface of the roll, and since it constitutes the outer surface that is always visible and touched in roll form, design and feel, such as softness and surface smoothness, are particularly important. Toilet paper 10 with an embossed pattern including linearly spaced recesses 32 and valley grooves 35 that extend in all directions from the recesses 32 to connect the recesses 32, has a design with a geometrically orderly impression and improved softness and surface smoothness. In particular, the valley grooves 35 facilitate overall stretch, making it suitable for improving the softness and surface smoothness of long toilet paper 10. It is preferable that the valley groove 35 has a constant depth or that the shallowest portion is located in the center between the recesses 32 .
[0030] The embossing pattern on the second sheet 12 does not necessarily have to be the same as that on the first sheet 11, but preferably, like the first sheet 11, it is a pattern having recesses 32 arranged in a straight line at a predetermined interval and valley grooves 35 that are shallower than the recesses 32 and extend in all directions from the recesses 32 to connect the recesses 32. It is also desirable that the valley grooves 35 on the second sheet 12 have a constant depth or that the shallowest part is in the center between the recesses 32. By using an embossing pattern similar to that on the first sheet 11, differences in paper quality and feel between the front and back of the toilet paper 10 are reduced.
[0031] The shape of the recesses 32 in this embodiment is not necessarily limited. Examples include a four-pointed star shape shown in FIGS. 2 and 3, a rectangle shown in FIG. 4, a circle shown in FIG. 5, and an ellipse shown in FIG. 6. Other shapes include a rounded rectangle. A four-pointed star shape surrounded by curves or straight lines shown in FIGS. 2 and 3 and a rectangle shown in FIG. 4 are preferred. The lines connecting the vertices of the rectangle and four-pointed star are preferably perpendicular to each other. A particularly preferred shape for the recesses 32 is a four-pointed star shape surrounded by curves shown in FIG. 2. When the recesses 32 are shaped like a four-pointed star surrounded by curves, the non-recessed portions between the recesses 32 become rounded rectangles and the edges of the recesses 32 are curved, which makes the recesses 32 feel smooth and soft to the touch. Furthermore, when the recesses 32 are shaped like a four-pointed star or a rectangle surrounded by curves or straight lines, the valley grooves 35 preferably extend from the four vertices of the recesses 32. The shape of the recesses 32 does not necessarily have to be the same on the first sheet 11 and the second sheet 12, but it is preferable that the shapes of the recesses 32 on the first sheet 11 and the second sheet 12 are the same. This reduces the difference in paper quality and feel between the front and back of the toilet paper 10.
[0032] Here, the toilet paper 10 according to this embodiment is characterized in that, in the first sheet 11, the direction LD in which the recesses 32 are arranged and the direction RD in which the valley grooves 35 extend do not coincide with the flow direction MD of the toilet paper 10. When the direction LD in which the recesses 32 are arranged and the direction RD in which the valley grooves 35 extend do not coincide with the flow direction MD of the toilet paper 10, collapse, crushing, and inversion of the recesses are improved. Here, the flow direction of the toilet paper 10 coincides with the winding direction and is the direction in which the toilet paper is pulled when wound into a roll or after being formed into a roll. This is generally the longitudinal direction (MD) of the paper. If the direction LD in which the recesses 32 are arranged and the direction RD in which the valley grooves 35 extend coincide with the flow direction of the toilet paper 10, it is thought that wrinkles along the flow direction, also known as vertical wrinkles, are more likely to occur due to tension differences between areas where recesses are intermittently arranged along the flow direction in the width direction and areas where the recesses are not arranged, or between areas where the valley grooves extend and areas where the valley grooves do not extend, due to tension differences when the toilet paper is wound into a roll or after being formed into a roll. It is believed that these wrinkles cause the recesses to collapse, crush, or turn over, resulting in the formation of convex portions. If the direction LD in which the recesses 32 are arranged and the extension direction RD of the valley grooves 35 do not match the flow direction MD of the toilet paper 10, vertical wrinkles are less likely to occur, and therefore the recesses are less likely to collapse, crush, or turn over, resulting in the formation of convex portions.
[0033] In particular, it is desirable that the direction LD in which the recesses are arranged be between ±10 degrees and 45 degrees relative to the direction MD of the toilet paper flow. The embossing pattern of the first sheet 11 in the illustrated form shows an example in which the direction LD in which the recesses are arranged is at a negative angle of ∠α in the clockwise direction relative to the direction MD of the toilet paper flow, but it may also be at a negative angle in the counterclockwise direction. When the direction LD in which the recesses are arranged is within the above range relative to the direction MD of the toilet paper flow, vertical wrinkles caused by tension during winding of the roll or after formation of the roll are particularly unlikely to occur, and the formation of convex portions due to the collapse, crushing, and inversion of the recesses caused by wrinkles is also further improved.
[0034] For the second sheet 12 as well, if the embossed pattern is configured so that the recesses 32 are arranged at predetermined intervals and further has valley grooves extending in all directions from the recesses 32 to connect the recesses, it is desirable that the direction LD in which the recesses 32 are arranged and the extension direction RD of the valley grooves 35 do not coincide with the direction of flow of the toilet paper in the second sheet 12. This makes it difficult for vertical wrinkles to occur in the second sheet 12 as well. Also, it is desirable that the direction LD in which the recesses are arranged is at an angle of between ±10 degrees and ±45 degrees with respect to the direction of flow MD of the toilet paper in the second sheet.
[0035] Furthermore, in the toilet paper 10 of this embodiment, it is desirable that the embossed pattern of the first sheet 11 and the embossed pattern of the second sheet 12 have a relationship such that the proportion of the number of recesses in the first sheet 11 that overlap with the recesses in the second sheet 12 in a plan view is 80% or less, preferably 75% or less. In other words, if the embossed patterns are such that 80 recesses in the second sheet overlap with 100 recesses in the first sheet 11, the proportion is 80%. In double-embossed toilet paper, similar to the toilet paper 10 of this embodiment, in which the sheet on the outer surface of the roll and the sheet on the inner surface of the roll are not bonded with an adhesive or the like, the positions of the convex portions (concave portions) of the sheet on the outer surface of the roll and the convex portions (concave portions) of the sheet on the inner surface of the roll are generally not adjusted. For this reason, when the sheet on the outer surface of the reel and the sheet on the inner surface of the reel are overlapped, there are randomly formed areas where the convex (concave) portions of the sheet on the outer surface of the reel coincide with the convex (concave) portions of the sheet on the inner surface of the reel, areas where the convex (concave) portions of the sheet on the outer surface of the reel are located in areas where the convex (concave) portions of the sheet on the inner surface of the reel are not formed, and areas where the convex (concave) portions of the sheet on the outer surface of the reel are located in areas where the convex (concave) portions of the sheet on the inner surface of the reel are not formed. This causes random interference on the paper surface between the convex (concave) portions of the sheet on the outer surface of the reel and the convex (concave) portions of the sheet on the inner surface of the reel, and is thought to be one of the causes of the concave portions of the sheet on the outer surface of the reel being crushed, collapsed, or turned over. As in this embodiment, when the pattern of the recesses 32 of the first sheet 11 and the pattern of the recesses 32 of the second sheet 12 are in a relationship such that when they are stacked on top of each other on a flat surface, the ratio of the number of overlapping recesses of the second sheet 12 to the number of recesses of the first sheet 11 is 80% or less, the crushing, collapse, and inversion of the recesses of the sheet on the outer surface of the winding can be further improved without adjusting the positions of the convex portions (recesses) of the sheet on the outer surface of the winding and the convex portions (recesses) of the sheet on the inner surface of the winding.
[0036] Furthermore, in terms of the number of overlaps between the recesses 32 on the first sheet 11 and the recesses 32 on the second sheet 12, it is desirable that the direction in which the recesses are arranged on the first sheet 11 and the direction in which the recesses are arranged on the second sheet 12 be in a range of opposite angles relative to the direction of flow MD of the toilet paper 10. That is, if the direction in which the recesses are arranged on the first sheet 11 is angled clockwise by an angle α relative to the direction of flow MD of the toilet paper as shown in FIG. 2, it is desirable that the direction in which the recesses are arranged on the second sheet 12 is angled counterclockwise by an angle β relative to the direction of flow MD of the toilet paper as shown in FIG. 12. Of course, the direction in which the recesses are arranged on the first sheet 11 may be angled counterclockwise, and the direction in which the recesses are arranged on the second sheet 12 may be angled clockwise. In particular, it is preferable that the embossing pattern on the second sheet be symmetrical to the embossing pattern on the first sheet 11, with the direction of flow MD of the toilet paper as the axis of symmetry. With such embossing patterns on the first sheet 11 and the second sheet 12, as in the case of toilet paper as shown in Figure 12, the direction LD in which the recesses 32 are arranged and the direction RD in which the valley grooves extend on the first sheet 11, and the direction LD in which the recesses 32 are arranged and the direction RD in which the valley grooves extend on the second sheet 12 do not coincide with the flow direction of the toilet paper, and without adjusting the positions of the recesses 32 on the first sheet 11 and the second sheet 12 in the flow direction MD of the toilet paper, the overlapping number of the recesses 32 on the first sheet 11 and the recesses 32 on the second sheet 12 can be reduced to 80% or less, making it less likely that the recesses will interfere with each other or be inverted, thereby further eliminating crushing, collapse, and inversion of the recesses.
[0037] On the other hand, in the toilet paper 10 of this embodiment, it is desirable that the height difference D1 between the deepest parts of the recesses 32 and the shallowest parts of the valley grooves 35 in at least the first sheet 11 is 0.01 to 0.30 mm. More preferably, it is 0.01 to 0.25 mm, and particularly preferably 0.01 to 0.20 mm. This range of height difference D1 can be said to be a very narrow range. When the height difference D1 between the deepest parts of the recesses 32 and the shallowest parts of the valley grooves 35 is 0.01 to 0.30 mm, the recesses are less likely to be crushed or collapsed, or to have convexly inverted portions. In long double-embossed toilet rolls, the formation of crushed or collapsed recesses and convexly inverted portions of recesses is thought to be due in part to interference between the convex portions when sheets with recesses and convexities formed by embossing are stacked together, pulling during sheet transport and winding, and inversion of recesses caused by pulling after formation of the roll. In particular, in an embossed pattern having recesses and valley grooves extending in all directions from the recesses to connect the recesses, it is believed that convex portions are easily formed due to inversion when the recesses are pulled along the valley grooves on all four sides when the toilet paper is wound into a roll or in the state of the roll after being wound. In an embossed pattern having such recesses and valley grooves extending in all directions from the recesses to connect the recesses, by reducing the height difference between the deepest part of the recess 32 and the shallowest part of the valley groove 35 to 0.01 to 0.30 mm as in this embodiment, inversion due to pulling is less likely to occur, and in combination with the other paper quality configurations and roll configuration, crushing, collapse of the recesses, and formation of convex portions due to inversion are improved.
[0038] If the embossed pattern on the second sheet 12 also has recesses 32 and valley grooves 35 extending in all directions from the recesses 32 to connect the recesses 32, the difference in height between the deepest part of the recesses 32 and the shallowest part of the valley grooves 35 is preferably 0.01 to 0.30 mm, as with the first sheet 11. It is particularly preferably 0.05 to 0.28 mm, and even more preferably 0.1 to 0.25 mm. The second sheet 12 also improves the collapse, crumbling, and turning over of the recesses, thereby reducing differences in paper quality and feel between the front and back of the toilet paper.
[0039] To achieve the difference between the deepest points of the recesses 32 and the shallowest points of the valley grooves 35 within the above range, the height difference between the highest points of the protrusions forming the recesses and the deepest points of the ridges forming the valley grooves on the embossing roll used during embossing should be 0.01 to 0.3 mm, preferably 0.05 to 0.2 mm or less, and particularly preferably 0.07 to 0.13 mm. At least when the height difference between the highest points of the protrusions forming the recesses and the deepest points of the ridges forming the valley grooves on the embossing roll used during embossing is 0.07 to 0.13 mm, the difference between the deepest points of the recesses and the shallowest points of the valley grooves can be in the range of 0.01 to 0.30 mm in the sheet according to the present invention.
[0040] The height difference between the deepest part of the recess 32 and the shallowest part of the valley groove 35 in this embodiment is measured using a one-shot 3D measuring macroscope VR-3200 manufactured by Keyence Corporation or an equivalent device, and image analysis software "VR-H1A" or an equivalent software. Note that, in the past, with double-embossed toilet paper, it was considered impossible or extremely difficult to measure the depth due to the crushing, crumbling and reversal of the recess, as described above, but with the toilet roll of this embodiment, the crushing, crumbling and reversal of the recess are improved, and further, by devising a measurement method, measurable recesses can be selected.
[0041] Measurements are performed at a magnification of 12x with a field of view of 24mm x 18mm. The sample used for measurement is a single cut taken between the perforations 10m from the end of the winding, excluding the tail seal, and separated into a first sheet 11 and a second sheet 12. The sample size is approximately 25mm long x 50mm wide. The sample is set on the measurement table so that there are no wrinkles or ripples that may occur when the sample is placed on the measurement table, and it is held in a position that does not affect the measurement field of view. For example, the sheet can be held down with a ring-shaped holder while being taut, without excessive tension.
[0042] The measurement procedure uses the above-mentioned equipment and software to select a recess suitable for confirming its shape and its elevation difference from its surroundings, referring to the colors representing elevations in the image obtained from a planar perspective. In other words, a recess that is nearly ideally formed by embossing is selected. Then, as shown in Figure 8, a measured profile curve is obtained along line segments A1 and A2 in the direction along the valley groove 35 of the selected recess 32 in the image shown from a planar perspective. Surface roughness components with wavelengths shorter than λc: 800 μm (where λc is the "filter defining the boundary between the roughness component and the waviness component" as defined in JIS-B0601, Section 3.1.1.2) are removed from this measured profile curve using a low-pass filter, resulting in a waviness curve Q1 as shown in Figure 9. For each of the undulation curves A1 and A2, the difference between the average value of the shallowest points S1 and S2 of the two valley grooves 35 and the deepest point G1 is calculated, and this average value is used as the height difference between the deepest point of the recess 32 and the shallowest point of the valley groove 35. The positions of the shallowest points S1 and S2 of the valley groove 35 and the position of the deepest point G1 on the undulation curve Q1 are determined visually with reference to the curve of the curve, an image of the recess shown from a planar perspective, and the line segments A1 and A2. The above measurements are performed for three embossments, and the average value is used as the final height difference.
[0043] The depth of the deepest part of the recesses 32 in the first sheet 11 is desirably 0.02 to 0.5 mm, preferably 0.03 to 0.3 mm, and particularly preferably 0.04 to 0.14 mm. If the depth is 0.02 to 0.5 mm, the recesses are less likely to collapse, be crushed, or be inverted to form convex portions, while still maintaining sufficient design.
[0044] The depth of the deepest portion of the recesses 32 in the second sheet 12 is desirably 0.02 to 0.5 mm, similar to that of the first sheet 11. It is preferably 0.03 to 0.3 mm, and particularly preferably 0.04 to 0.14 mm. It is particularly desirable for the depth of the deepest portion of the recesses 32 in the second sheet 12 to be within the above range, regardless of the shape of the recesses 32 or the presence or absence of valley grooves 35. The recesses 32 formed in the second sheet 12 have corresponding convex portions that face the convex portion-forming surface of the first sheet 11. Therefore, the convex portions corresponding to the recesses in the second sheet 12 may press against the convex portions corresponding to the recesses in the first sheet 11, which may cause the recesses in the first sheet 11 to invert or collapse. By setting the depth of the recesses 32 in the second sheet 12 within the above range, interference with the convex portions corresponding to the recesses in the first sheet 11 is reduced. This is particularly effective when the paper quality, such as the basis weight and thickness, of the sheet according to the present invention and the winding density, which will be described later, are considered.
[0045] In order to set the depth of the deepest part of the recesses 32 within the above range, the height of the highest part of the protrusions for forming the recesses formed on the embossing roll used during embossing is 0.05 to 1.3 mm, preferably 0.3 to 1.0 mm, and particularly preferably 0.5 to 0.9 mm. At least in the sheet according to the present invention, when the height of the highest part of the protrusions for forming the recesses formed on the embossing roll used during embossing is 0.05 to 1.3 mm, the depth of the deepest part can be set within the above range.
[0046] The depth D2 of the deepest portion of the recess 32 according to this embodiment, similar to the elevation difference D1 between the deepest portion of the recess 32 and the shallowest portion of the valley groove 35, is measured using a one-shot 3D measuring macroscope VR-3200 or equivalent manufactured by Keyence Corporation and image analysis software "VR-H1A" or equivalent software. The measurement procedure, sample collection, sample placement, and measurement method are the same as those for the elevation difference D1 between the deepest portion of the recess 32 and the shallowest portion of the valley groove 35. However, as shown in FIG. 8, the measurement position is a position that straddles the non-recessed portion 34, the recess 32, and the non-recessed portion 34 other than the valley groove 35, and a measured cross-sectional curve is obtained along lines B1 and B2 at this position. Then, by performing the same processing as for the elevation difference D1 between the deepest portion of the recess 32 and the shallowest portion of the valley groove 35, a waviness curve Q2 as shown in FIG. 10 is obtained. For each of the undulation curves B1 and B2, the difference between the average value of the boundary positions P1 and P2 between the two non-depressed portions 34 and the recessed portions 32 and the deepest portion G2 is calculated, and this average value is taken as the depth D2 of the deepest portion of the recessed portions 32. The positions of the boundary positions P1 and P2 between the non-depressed portions 34 and the recessed portions 32 on the undulation curve Q2 and the position of the deepest portion G1 are determined visually with reference to the curve of the curve, an image of the recessed portions shown from a planar perspective, and the line segments B1 and B2. The above measurements are performed for three embossments, and the average value is taken as the final height difference.
[0047] On the other hand, the width L4 of the recess 32 in the first sheet 11 is preferably 1.15 to 1.31 mm. The width L4 of the recess 32 is the distance between the opposing edges in the case of a rectangle, a rounded rectangle, or a four-pointed star, as shown in Fig. 3, and is the diameter in the case of a circle, and is the major and minor axes in the case of an ellipse. If the width is 1.15 to 1.31 mm, the inverted portions of the recess 32 are reduced while maintaining sufficient design.
[0048] The width of the recesses 32 in the second sheet 12 is preferably 1.15 to 1.31 mm, similar to that of the first sheet. The area of the recesses is also preferably in the same range as that of the first sheet 11. The recesses in the second sheet 12 are also prevented from being crushed, crumbled, or turned upside down, and differences in paper quality and feel between the front and back of the toilet paper are reduced.
[0049] To set the recess width L4 within the above range, the width of the protrusions for forming the recesses formed on the embossing roll used during embossing is set to approximately 1.15 to 1.31 mm, and the nip pressure during embossing is adjusted.
[0050] The width of the recess 32 in this embodiment is also measured using a Keyence Corporation OneShot 3D Measuring Macroscope VR-3200 or equivalent and image analysis software "VR-H1A" or equivalent. The measurement procedure, sample collection, sample placement, and the height difference between the deepest point of the recess 32 and the shallowest point of the valley groove 35 are similar. The width of the recess is measured by visually checking the edges of the recess and measuring the distance between the edges, using the colors representing the heights in the image shown in the plan view as a reference. The measured cross-sectional curve and waviness curve of the line portion can be used as a reference to measure the distance between the edges.
[0051] Furthermore, in the first sheet 11, the spacing (pitch) L5 between the recesses 32 is preferably 5.05 to 5.35 mm. This spacing L5 between the recesses 32 is the distance between adjacent recesses 32 without a valley groove 35 in between, and is the spacing in the direction in which the recesses 32 are aligned on a straight line according to this embodiment. When the spacing L5 between the recesses 32 is 5.05 to 5.35 mm, the formation of convex portions due to crushing, collapse, and inversion of the recesses is more unlikely to occur. Furthermore, the difference in shape between the recesses and non-recesses is sufficiently visible, resulting in excellent design.
[0052] The spacing (pitch) between the recesses in the second sheet is also desirably 5.05 to 5.35 mm, similar to that of the first sheet 11. This prevents the recesses in the second sheet from being crushed, crumbled, or turned upside down, and reduces the difference in paper quality and feel between the front and back of the toilet paper 10.
[0053] The distance L5 (pitch) between the recesses 32 is set to approximately 5.05 to 5.35 mm, which is the distance (pitch) between the protrusions for forming the recesses on the embossing roll used during embossing, and the nip pressure during embossing can be adjusted.
[0054] The distance L5 (pitch) between the recesses 32 in this embodiment can also be measured using a Keyence Corporation OneShot 3D Measuring Macroscope VR-3200 or equivalent and image analysis software "VR-H1A" or equivalent. The measurement procedure, including sample collection, sample placement, and the elevation difference between the deepest point of the recess 32 and the shallowest point of the valley groove 35, are similar. The distance L5 between the recesses 32 is measured by visually checking the edges of the recesses while referring to the color representing the elevation in the image displayed in the plan view. The measured cross-sectional curve and waviness curve of the line portion can be used as a reference to measure the distance between the edges of the two recesses.
[0055] The area of the recesses 32 and the embossed area ratio (total area of recesses / total area of sheets) in the toilet paper 10 of this embodiment are not necessarily limited, but the area of the recesses 32 of the first sheet 11 and the second sheet is 0.5 to 8 mm 2 is preferable, and 1.0 to 3.2 mm 2 The embossed area ratio is preferably 15 to 28%, and more preferably 8 to 14%.
[0056] The area of the recesses 32 and the embossed area ratio in this embodiment are also measured using a Keyence Corporation One-Shot 3D Measuring Macroscope VR-3200 or equivalent and image analysis software "VR-H1A" or equivalent. The embossed area ratio is calculated from the area of the recesses and the number of recesses in an area of 10 cm in the flow direction. As with the width of the recesses 32, the area is measured by visually checking the edges of the recesses using the colors representing the heights and depths in the image shown in plan view as a reference, and then calculating the area of the recesses. In this case, the height profile of the line portion extending beyond the edges can be used as a reference.
[0057] On the other hand, the toilet roll of this embodiment has a winding density of 0.75 to 1.6. A winding density in this range can reduce the crushing, crumbling, and inversion of recesses caused by embossing, due to the relationship between the degree of compaction of the toilet paper during and after winding, the basis weight, and the embossing pattern. The winding density is calculated by (paper thickness x winding length x number of plies) ÷ (cross-sectional area of the roll). The cross-sectional area of the roll is also calculated by {cross-sectional area of the roll's winding diameter (outer diameter) L1} - (cross-sectional area of the paper tube's outer diameter L3).
[0058] On the other hand, the tensile strength of the toilet paper of this embodiment is not necessarily limited, but the dry tensile strength in the machine direction is preferably 250 cN / 25 mm or more and 360 cN / 25 mm or less, and the dry tensile strength in the cross direction is preferably 65 cN / 25 mm or more and 120 cN / 25 mm or less. With such a dry tensile strength, the convex portions are less likely to collapse, be crushed, or be inverted, and the firmness required during use can be obtained.
[0059] Dry tensile strength is measured in accordance with JIS P 8113 (2006) as follows. Test specimens are cut to approximately 25 mm (±0.5 mm) wide x 150 mm long in both the longitudinal and transverse directions. Test specimens are measured as multi-ply. The test equipment used is a Minebea Co., Ltd. load cell tensile tester TG-200N or equivalent. The grip spacing is 100 mm, and the tensile speed is set to 100 mm / min for longitudinal measurements and 50 mm / min for transverse measurements. Measurements are performed by clamping both ends of the test specimen into the grips of the tester, applying a tensile load in the vertical direction to the paper, and reading the digital value when the paper breaks. Five sets of specimens are prepared in both the longitudinal and transverse directions, and measurements are taken five times. The average of these measurements is the dry tensile strength in each direction.
[0060] On the other hand, the toilet paper 10 according to this embodiment may contain known dry strength agents, dry strength agents, and temporary wet strength agents, but because strength agents can particularly reduce softness and water disintegrability, it is preferable that these strength agents are not added. Therefore, it is preferable that the toilet paper of this embodiment does not contain at least one, preferably two, and particularly all of the dry strength agents, dry strength agents, and temporary wet strength agents.
[0061] In addition, the toilet paper 10 of this embodiment preferably contains a softener. Examples of softeners include fatty acid ester-based softeners and cationic fatty acid amide-based softeners. The fatty acid ester-based softener may be either a cationic fatty acid ester-based compound or a nonionic fatty acid ester-based compound, and multiple types may be added. Examples of cationic fatty acid amide-based softeners include a reaction product of an amide compound obtained by reacting polyalkylene polyamines with monocarboxylic acids and epihalohydrin. The content of the softener is not necessarily limited, but is preferably 0.5 to 4.0 kg / t of pulp.
[0062] Here, the toilet roll 1 of this embodiment has a TS750 value of the outer surface side of the roll of the first sheet 11 measured by a tissue softness measuring device TSA of 12.0 dBV at a winding length of 37.5 to 60 m. 2 rms, 13.0 dBV for winding lengths of 75 to 125 m 2 It is desirable that it is below rms.
[0063] The tissue softness measuring device TSA according to this embodiment is a tissue softness measuring device TSA manufactured by Emtec Electronic GmbH (Japan distributor: Nippon Luft Co., Ltd.) in Germany, or an equivalent device. TS750 in this embodiment is a value measured using this tissue softness measuring device TSA manufactured by Emtec. TS750 is the intensity of the first maximum peak in the spectrum from the low-frequency side, obtained when a bladed rotor is pressed from above onto a sample placed on a sample stage with a pressure of 100 mN, then rotated at a speed of 2.0 rpm, and the vibration of the sample stage is measured with a vibration sensor. TS750 is a parameter affected by "smoothness / roughness." For measurements using the tissue softness measuring device TSA according to this embodiment, a sample was processed into a circle with a diameter of approximately 112.8 mm using an Emtec sample punch, and the software used for analysis and quantification was the emtec measurement system.
[0064] Furthermore, the toilet paper 10 of this embodiment preferably has a softness of 3.0 cN / 100 mm or less, and particularly preferably 2.8 to 1.0 cN / 100 mm. This softness is measured using the handle-o-meter method in accordance with JIS L 1096 (2010) Method E. If the softness is within the above range, the quality, such as surface texture and softness, is sufficient.
[0065] The pulp fibers in the toilet paper 10 of this embodiment are not particularly limited, but are preferably 70 to 100% by mass virgin pulp and 0 to 30% by mass recycled paper pulp. Blending recycled paper pulp allows for more cost-effective production than 100% virgin pulp. Furthermore, recycled paper pulp tends to have finer fibers than the pulp fibers before recycling during the process of recycling recycled paper. Due to this fiber nature, the fibers become denser without increasing the paper thickness, but the finer fibers make it difficult to achieve paper strength. Blending too much recycled paper pulp reduces texture, such as flexibility and smoothness. Therefore, in consideration of the characteristics of recycled paper pulp, it is best to set the blending ratio within the range of 0 to 30% by mass. However, from the standpoint of paper strength and quality, 100% virgin pulp is particularly desirable. In this case, the virgin pulp is preferably a combination of softwood kraft pulp (NBKP) and hardwood kraft pulp (LBKP). The blending ratio of these pulps is preferably NBKP:LBKP 20:80 to 50:50. When using recycled paper pulp, the type is not necessarily limited, but recycled paper pulp made from recycled milk carton paper or high-quality recycled paper is particularly desirable. These pulps contain a large amount of softwood kraft pulp (NBKP) or hardwood kraft pulp (LBKP) derived from the raw materials, making them easy to develop paper strength. [Example]
[0066] Next, examples and comparative examples of toilet rolls according to the present invention were produced, and measurements of physical properties and sensory evaluations of collapse of recesses, etc. were carried out. The toilet paper in the examples and comparative examples was a double-embossed two-ply sheet in which recesses and corresponding protrusions were formed by embossing on the sheets located on the outer and inner sides of the roll, with the protrusion-formed surfaces facing each other. Both the examples and comparative examples used base paper made from 100% virgin pulp. In Example 1, Example 1C and Comparative Example 1, the winding length was 45 m, which was about 1.5 times the winding length of a normal product. In Example 2, Example 2C and Comparative Example 2, the winding length was 60 m, which is about twice the winding length of the normal product. In Example 3, Example 3C and Comparative Example 3, the winding length was 80 m, which is about three times the winding length of a normal product. In Example 4, Example 4C and Comparative Example 4, the winding length was 106 m, which was about 4.2 times that of the normal product. The embossing pattern of the first sheet according to Examples 1, 2, 3, and 4 is the pattern shown in Fig. 2, where the shape of the recesses is a four-pointed star, the shape of the recesses is a four-pointed star, and the angle between the direction LD of the recesses and the flow direction MD is -30 degrees. The embossing pattern of the second sheet is the pattern shown in Fig. 11, where the shape of the recesses is a four-pointed star, the shape of the recesses is a four-pointed star, and the angle between the direction LD of the recesses and the flow direction MD is 30 degrees. Furthermore, in the embossing patterns of the first sheet according to Examples 1, 2, 3, and 4, the direction in which the recesses are arranged and the extension direction of the valley grooves do not coincide with the flow direction of the toilet paper. The embossing pattern of the first sheet according to Examples 1C, 2C, 3C, and 4C is the pattern shown in Fig. 2, where the recesses are four-pointed star shaped, and the angle between the direction LD of the recesses and the flow direction MD is -30 degrees. The embossing pattern of the second sheet is the pattern shown in Fig. 12, where the recesses are square shaped, and the recesses are four-pointed star shaped, and the angle between the direction LD of the recesses and the flow direction MD is 60 degrees. Furthermore, in the embossing patterns of the first sheets according to Examples 1C, 2C, 3C, and 4C, the direction in which the recesses are arranged and the extension direction of the valley grooves do not coincide with the flow direction of the toilet paper. The toilet paper according to Comparative Examples 1 to 4 has the embossing pattern shown in Fig. 13, and the recesses on both the outer sheet of the roll (first sheet in the front) and the inner sheet of the roll (second sheet in the front) are four-pointed star-shaped, and the direction in which the recesses are arranged matches the direction of the toilet paper flow (the angles corresponding to ∠α and ∠β are 0 degrees).The directions in which the recesses are arranged on the outer sheet of the roll (first sheet in the front) and the inner sheet of the roll (second sheet in the front) are also designed to match. In addition, no dry strength agent, wet strength agent, or temporary wet strength agent was added to the base paper of the toilet paper in the Examples and Comparative Examples. The softener was used in the same blend ratio in the Examples and Comparative Examples. For the sensory evaluation of the depressions, a random area measuring 25 mm long and 50 mm wide was set 10 m from the outside of the roll, and the state of the depressions and the occurrence of vertical wrinkles within the area were visually inspected and evaluated. Five subjects were assigned scores, and the average score was rounded to the nearest 0.5. The evaluation scores for "depression, crumbling, and inversion of depressions" were as follows: "Depression, crumbling, and inversion observed in all depressions" (1 point); "Depression, crumbling, and inversion observed in almost all depressions" (2 points); "Depression, crumbling, and inversion observed in depressions" (3 points); and "No depressions observed in depressions" (4 points). For "vertical wrinkles," the evaluation scores were as follows: "Vertical wrinkles observed across the entire width of the roll" (1 point); "Three or more vertical wrinkles observed, but not across the entire roll" (2 points); "One to two vertical wrinkles observed" (3 points); and "No vertical wrinkles observed" (4 points).
[0067] [Table 1]
[0068] As shown in Table 1, when comparing Example 1, Example 1A and Comparative Example 1, Example 2, Example 2A and Comparative Example 2, Example 3, Example 3A and Comparative Example 3, Example 4, Example 4A and Comparative Example 4, which have the same winding length, the TS750 values of the Examples are superior to the TS750 values of the Comparative Examples. This indicates that the Examples are evaluated as being superior in surface smoothness. In the sensory evaluation test, the comparative examples 2 to 4, which had a winding length of 2 times or more, were evaluated as "crushed, crumbled, and turned over in all recesses," whereas the examples were evaluated as "no crushed, crumbled, or turned over in recesses" even at a winding length equivalent to 4 times winding. Note that the depth of recesses in the table is the design value for recesses that could not be measured due to crushed, crumbled, or turned over. From the above results, the toilet roll according to the present invention improves the collapse and crumbling of the recesses and the formation of areas where the recesses are inverted into convex shapes, improving smoothness and fluffy softness. [Explanation of symbols]
[0069] 1... toilet roll, 10... toilet paper, 11... first sheet, 12... second sheet, 20... paper tube (tube core), 31... convex portion, 32... concave portion, 34... non-convex portion, 35... valley groove, L1... toilet roll winding diameter (diameter), L2... toilet roll width, L3... toilet roll tube diameter, L4... concave portion width, L5... distance between concave portions, LD... direction of concave portions, RD... extension direction of valley groove, MD... direction of toilet paper flow, ∠α... angle between the direction of concave portions of the first sheet and the direction of toilet paper flow, ∠β... angle between the direction of concave portions of the second sheet and the direction of toilet paper flow, 110... comparative toilet paper, 111... sheet on the outer surface of the winding according to the comparative example, 112... sheet on the inner surface of the winding according to the comparative example, 132... concave portion according to the comparative example, 135... valley groove according to the comparative example.
Claims
1. A toilet roll in which two-ply double-embossed toilet paper sheets are wound around a paper tube, the two sheets being laminated together such that the convex portions face each other, the first sheet having embossed recesses and convex portions corresponding to the recesses and located on the outer surface of the roll, and the second sheet having embossed recesses and convex portions corresponding to the recesses and located on the inner surface of the roll, the convex portions of which are laminated together such that the convex portions face each other, The toilet roll is The winding length is 45 m or more, the roll diameter is 110 to 130 mm, and the winding density is 0.75 to 1.6, The toilet paper is Basis weight per ply: 11.0 to 18.0 g / m ２ The thickness of the two plies is 125 to 205 μm, and the thickness of the first sheet is 65 to 120 μm; The embossed pattern of at least the first sheet is The toilet paper has recesses arranged in a straight line at a predetermined interval and valley grooves that are shallower than the recesses and extend in all directions from the recesses to connect the recesses, and the direction in which the recesses are arranged and the extension direction of the valley grooves do not coincide with the direction in which the toilet paper flows. A toilet roll characterized by:
2. 2. The toilet roll according to 1, wherein the direction in which the recesses are arranged is at an angle of ±10 degrees to 45 degrees relative to the direction of flow of the toilet paper.
3. 3. The toilet roll according to claim 1 or 2, wherein the shape of the recesses in the first sheet is a square or a four-pointed star, and the valley grooves extend from the four vertices of the recesses.
4. The toilet roll according to claim 3, wherein the distance between the recesses of the first sheet is 5.05 to 5.35 mm.
5. The toilet roll according to claim 3 or 4, wherein the width of the recessed portion of the first sheet is 1.15 to 1.31 mm.
Citation Information
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