Kitchen towel roll

Abstract

To provide a kitchen towel roll which is compact, hardly causes core crush, and is excellently wound around a core even in a kitchen towel having unevenness on a surface and excellent in water absorbency.SOLUTION: Provided is a kitchen towel roll that is formed by winding two to three plies of laminated kitchen towels around a core into a roll, wherein the kitchen towels have a basis weight of 30 g / m2 or more and 56 g / m2 or less, a water absorption per unit area of 300 g / m2 or more and 600 g / m2 or less, and when the root mean square height Sq2 of the surface roughness of the core surface that comes into contact with the kitchen towels is 8 μm or less, a roll density of 0.04 g / cm3 or more and 0.13 g / cm3 or less.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a kitchen towel roll containing an embossed pattern. [Background technology]

[0002] In recent years, various kitchen towel sheets and kitchen towel rolls made by rolling up such kitchen towels have been developed and sold. Kitchen towels are required to be soft and absorbent, and Patent Document 1, for example, discloses a through-air dried (TAD) absorbent towel paper web. TAD kitchen towels have irregularities due to the papermaking process, which makes them bulky and highly absorbent.

[0003] Kitchen towels are available in rolls and soft packs, but in the case of rolls, they are generally wound around a paper tube (also called a core). Paper tubes are often made from paper, which is made using recycled paper pulp or mechanical pulp. When mechanical pulp is used in particular, the thickness of the paper is high, making it an environmentally friendly and resource-saving core. However, as the paper becomes thicker, it also becomes weaker, making it more susceptible to core collapse.

[0004] However, when mechanical pulp is used for the core, the paper becomes thicker, which in turn increases the surface roughness, resulting in poor surface quality for the core. Even if the core has poor surface quality, this is not a particular problem for ordinary kitchen towels. However, in the case of TAD's kitchen towels, the kitchen towels have unevenness due to the papermaking process, which reduces the contact area between the core and the kitchen towel when wrapping the sheet around the core using pickup glue, making it difficult to wrap the sheet properly.

[0005] Furthermore, because TAD kitchen towels are thicker, their roll density is lower than that of kitchen towels made using standard dry crepe papermaking. However, even at low roll density, the rolls are tightly wound, making them more susceptible to core crushing when cut with a log saw. Therefore, if the roll density is reduced to prevent core crushing, the roll will be less compact.

[0006] Next, when the NBKP content was increased to ensure the core strength and improve the surface properties of the core, the core strength could be ensured, but the surface properties could not be significantly improved, and the winding of the sheet was inferior. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2024-16101 Summary of the Invention [Problem to be solved by the invention]

[0008] To provide a kitchen towel roll that has been made in view of the above circumstances, and that is compact, does not easily cause core crushing, and can be easily wound around a core, even if the kitchen towel has an uneven surface and is excellent in water absorption. [Means for solving the problem]

[0009] After extensive research, the inventors discovered that the above-mentioned problems could be solved by specifying the basis weight and water absorption per unit area of ​​the kitchen towels, the surface roughness of the core surface, and the roll density in a kitchen towel roll formed by winding two to three plies of kitchen towels around a core, and thus completed the present invention.

[0010] That is, the present invention was completed by setting the blending ratio of LBKP at a certain level or more to improve the surface properties of the core so that a highly absorbent kitchen towel with an uneven surface can be properly wound around the core, and by keeping the blending ratio within a certain range so that the roll density does not increase and the core is not crushed even if the blending ratio is increased.

[0011] (1) A first aspect of the present invention is a kitchen towel roll in which two to three plies of kitchen towels are laminated and wound around a core in a roll shape, and the kitchen towels have a basis weight of 30 g / m 2 More than 56g / m 2 Below, the water absorption per unit area is 300g / m 2 More than 600g / m 2 When the root mean square height of the surface roughness of the core surface that contacts the kitchen towel is Sq2, Sq2 is 8 μm or less, and the roll density is 0.04 g / cm 3 More than 0.13g / cm 3 A kitchen towel roll characterized by the following:

[0012] (2) A second aspect of the present invention is the kitchen towel roll according to (1), characterized in that the core contains 30% by mass or more of LBKP (hardwood bleached kraft pulp).

[0013] (3) A third aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that when the root mean square height of the surface roughness of the surface of the kitchen towel that contacts the core is Sq1, the value represented by the product of Sq1 and Sq2 is 100 or more and 530 or less.

[0014] (4) A fourth aspect of the present invention is the kitchen towel roll according to (1) or (2), characterized in that the kitchen towel has irregularities resulting from the papermaking process.

[0015] (5) A fifth aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the kitchen towel does not have an embossed pattern on the surface that contacts the core.

[0016] (6) A sixth aspect of the present invention is the kitchen towel roll according to (1) or (2), characterized in that the Sq1 is 38 μm or more and 125 μm or less.

[0017] (7) A seventh aspect of the present invention is the kitchen towel roll according to (1) or (2), characterized in that the core is made of multiple layers of paper.

[0018] (8) The eighth aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the water absorption per unit mass of the kitchen towel is 7 g / g or more and 14 g / g or less.

[0019] (9) A ninth aspect of the present invention is the kitchen towel roll according to (1) or (2), characterized in that the roll length is 18 m or more and 45 m or less.

[0020] (10) A tenth aspect of the present invention is the kitchen towel roll according to (1) or (2), characterized in that the kitchen towel has a linear embossed pattern.

[0021] (11) An eleventh aspect of the present invention is the kitchen towel roll according to (10), characterized in that the embossing pattern includes radial embossing and closed-ring structure embossing.

[0022] (12) The twelfth aspect of the present invention is the kitchen towel roll according to (11), characterized in that the radial embossments and the closed ring structure embossments are alternately arranged at equal intervals.

[0023] (13) The thirteenth aspect of the present invention is the kitchen towel roll according to (12), characterized in that the arrangement angle of adjacent identical patterns of the radial embossing and the closed ring structure embossing is 20° or more and 80° or less relative to the CD direction of the kitchen towel. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a kitchen towel roll that has an uneven surface and excellent water absorption, yet is compact, is less likely to cause core crushing, and is easily wound around the core. [Brief explanation of the drawings]

[0025] [Figure 1] 1 is a perspective view of a kitchen towel roll according to an embodiment of the present invention. [Figure 2] FIG. 1 is a diagram showing an example of an embossing pattern in a kitchen towel roll of the present invention. [Figure 3] FIG. 2 is a diagram showing an example of a radial embossing and a closed-ring structure embossing of an embossing pattern in the kitchen towel roll of the present invention. [Figure 4] FIG. 1 is a diagram showing a method for measuring the arrangement angle of the embossed pattern in the kitchen towel roll of the present invention. [Figure 5] FIG. 1 is a diagram showing a height profile on the XY plane as observed by a microscope using shading. [Figure 6] FIG. 1 is a graph showing a height profile on the XY plane obtained by a microscope. [Figure 7] FIG. 10 is a diagram showing how to determine the embossing depth for an embossing pattern. [Figure 8] FIG. 10 is a diagram showing the height profile of a non-embossed portion on the XY plane as viewed under a microscope, using gray scales. [Figure 9] FIG. 1 is a diagram showing a method for measuring the water absorption of the kitchen towel sheet of the present invention. [Figure 10] 1 is a diagram showing a part of the papermaking process for the kitchen towel sheet of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0026] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0027] In this specification, "kitchen towel roll" (hereinafter simply referred to as "roll") refers to a roll product in which kitchen towels are wound into a roll. "Kitchen towel sheet" (hereinafter simply referred to as "sheet") refers to a sheet-like product in which kitchen towels are pulled out from a kitchen towel roll and cut along the perforations.

[0028] "MD direction" refers to the direction in which the paper runs on the machine, and "CD direction" refers to the direction perpendicular to the MD direction. In this specification, "MD direction of the roll" refers to the direction in which the kitchen towel is wound (Y direction in Figure 1), and "CD direction of the roll" refers to the direction perpendicular to the direction in which the kitchen towel is wound (X direction in Figure 1). "Axial direction" refers to the axial direction of the roll, which is the CD direction of the roll (X direction in Figure 1).

[0029] In this specification, the term "product ply" refers to a kitchen towel in which the number of plies is in a product state, without peeling off the stacked plies into a single sheet.

[0030] <Kitchen towel roll> Fig. 1 is a perspective view of a kitchen towel roll 1 according to one embodiment of the present invention. As shown in Fig. 1, the kitchen towel roll 1 according to this embodiment is a kitchen towel roll 1 wound into a roll of kitchen towel 1x, which is made by laminating two or three plies of sheets each having an embossed pattern 12 on at least the front ply. Preferably, the kitchen towel 1x has perforations 1c formed in the width direction of the roll at approximately equal intervals in the winding direction of the roll.

[0031] As shown in Figure 1, the surface of the kitchen towel 1x facing the outside of the roll is referred to as surface 1a (surface of the kitchen towel 1x), and the surface facing the center of the roll is referred to as back surface 1b (back surface of the kitchen towel 1x). Also, the edge of the kitchen towel 1x is referred to as the outermost edge 1e of the kitchen towel roll 1.

[0032] The kitchen towel roll 1 can be used, for example, as a roll of kitchen paper (sometimes called paper towel or cooking paper) used in home kitchens, restaurant kitchens, etc. to wipe away moisture or oil and remove dirt, as well as other rolls of sanitary paper.

[0033] <Kitchen towel> The kitchen towel 1x can be made by layering base paper after a papermaking process, embossing if necessary, and then winding it into a roll to form the kitchen towel roll 1. Alternatively, the base paper may be embossed before being layered and wound into a roll.

[0034] (Paper making method) The kitchen towel 1x is preferably produced by a TAD (through-air drying) papermaking method. The TAD papermaking method is a method in which air drying is performed during the dehydration and drying step of the papermaking process (preferably without press-dehydrating the wet paper). By producing the kitchen towel 1x by the TAD papermaking method, the kitchen towel 1x can be provided with unevenness derived from the papermaking process, resulting in a bulky, soft kitchen towel 1x with excellent water absorbency.

[0035] (raw materials) The kitchen towel 1x may contain pulp fibers. The pulp fibers are preferably composed of 100% by mass of wood pulp containing at least one of NBKP (softwood bleached kraft pulp fiber) and LBKP. The mass ratio of NBKP to LBKP (NBKP:LBKP) is preferably 40% by mass to 100% by mass to 0% by mass to 60% by mass. If the mass ratio of NBKP to LBKP is set outside the above range, the pulp contains too many short fibers, resulting in low strength and making it difficult to wind the kitchen towel around a core. On the other hand, if the mass ratio of NBKP to LBKP is set within the above range, the fiber length contained in the pulp is appropriate, resulting in appropriate core strength and making it easier to wind the kitchen towel around the core. The mass ratio of NBKP to LBKP is more preferably 50% by mass to 90% by mass to 10% by mass to 50% by mass, and even more preferably 60% by mass to 80% by mass to 20% by mass to 40% by mass.

[0036] (Wet pulp blend) The wet pulp fiber content in the kitchen towel 1x is preferably 50% or more, more preferably 70% or more, and even more preferably 90% or more. If the wet pulp fiber content is 50% or more, the kitchen towel 1x has good water absorbency.

[0037] (Uneven pattern resulting from the papermaking process) The surface of the kitchen towel 1x preferably has irregularities 11 resulting from the papermaking process, as shown in Figure 2. If the surface does not have irregularities 11 resulting from the papermaking process, the water absorbency of the kitchen towel 1x will be poor.

[0038] (Number of plies) The number of plies in the kitchen towel 1x is 2 to 3. If the number of plies is less than 2, the absorbency of the roll 1 is poor, and if the number of plies is more than 3, the compactness is poor. In addition, the roll becomes tightly wound, and the core 1d is easily crushed. The number of plies is preferably 2.

[0039] (Paper thickness per 10 plies) The lower limit of the paper thickness per 10 plies of the kitchen towel 1x (hereinafter simply referred to as "paper thickness per 10 plies") is preferably 2.0 mm or more, more preferably 2.3 mm or more, and even more preferably 2.6 mm or more. The upper limit of the paper thickness per 10 plies is preferably 4.0 mm or less, more preferably 3.6 mm or less, and even more preferably 3.3 mm or less. If the paper thickness per 10 plies is less than 2.0 mm, the water absorbency is poor. If the paper thickness per 10 plies exceeds 4.0 mm, the kitchen towel 1x becomes too thick and difficult to wrap around the core 1d. Furthermore, the wrap becomes too tight, making the core 1d more likely to be crushed.

[0040] (Paper thickness per product ply) The paper thickness per product ply of the kitchen towel 1x (hereinafter simply referred to as "paper thickness per product ply") is preferably 0.40 mm or more, more preferably 0.46 mm or more, and even more preferably 0.52 mm or more. The upper limit of the paper thickness per product ply is preferably 0.80 mm or less, more preferably 0.72 mm or less, and even more preferably 0.68 mm or less. If the paper thickness per product ply is less than 0.40 mm, the absorbency is poor. If the paper thickness per product ply exceeds 0.80 mm, the kitchen towel 1x becomes too thick and difficult to wrap around the core 1d. Furthermore, the wrap becomes too tight, making the core 1d more likely to be crushed.

[0041] The paper thickness was measured using the following method. A thickness gauge (a dial thickness gauge called "PEACOCK" manufactured by Ozaki Seisakusho Co., Ltd.) was used. The measurement conditions were a load of 3.7 kPa and a probe diameter of 30 mm. The sample was placed between the probe and the measuring table, and the gauge reading was taken when the probe was lowered at a speed of 1 mm per second or less. To measure the paper thickness per 10 plies, 10 plies (5 sets of 10 2-ply sheets) were stacked and measured 10 times, and the measurement results were averaged. For a 3-ply sheet, 9 plies (3 sets of 3-ply sheets) were stacked and measured, and the thickness per ply was calculated from the measurement results and converted to 10 plies. The paper thickness per product ply was calculated by converting the thickness per ply into the number of product plies. The paper thickness was measured at 10 points: five different points in the MD (Y direction in Figure 2) of the sheet 10, and five points shifted from these five points in the CD (X direction in Figure 2). It is important to measure the paper thickness at 10 different points, but the exact position is not important.

[0042] (Basic weight) The basis weight of the product ply for one kitchen towel is 30 g / m 2 More than 56g / m 2 The basis weight of the product ply is 30 g / m 2 If it is less than 56g / m, the absorbency will be poor. 2 If the weight exceeds this, the kitchen towel 1x will become stiff and difficult to wrap around the core 1d. The minimum weight limit for the product ply is 34 g / m 2 More than 38g / m 2 More preferably, the upper limit is 50 g / m 2 Less than 46 g / m 2 The following is more preferable: The basis weight is measured in accordance with JIS P 8124.

[0043] (specific volume) The specific volume of one kitchen towel is 10cm 3 / g or more 19cm 3 / g or less. The specific volume is preferably 10 cm 3 If it is less than 19cm / g, the absorbency is poor. 3If the specific volume of the kitchen towel exceeds 11 cm / g, the kitchen towel 1x becomes stiff and difficult to wrap around the core 1d. 3 / g or more is more preferable, and 13cm 3 / g or more is more preferable. The upper limit is 17 cm 3 / g or less is more preferable, and 16cm 3 The specific volume of 1x kitchen towel is calculated by dividing the paper thickness of a predetermined number of plies (for example, product plies) of 1x kitchen towel by the basis weight of the predetermined number of plies, and then calculating the volume cm per unit g. 3 It is expressed as:

[0044] (Embossed) Preferably, the kitchen towel 1x is laminated into two or three plies, more preferably two plies, after embossing at least the ply on the surface 1a. When laminating into two or three plies, it is preferable to use, for example, ply bond glue and apply the glue for adhesion. By bonding the plies together in this way to form two plies, the plies are more strongly bonded together, and the kitchen towel 1x is less likely to tear or peel even when wet. Alternatively, water may be used instead of ply bond glue, or a mixture of glue and water may be used.

[0045] (embossed pattern) The embossing of the kitchen towel 1x preferably has an embossing pattern 12 in which two or more patterns are arranged at regular intervals. The embossing pattern 12 makes the stacked plies less likely to peel off, making it easier to wind around the core 1d. It is even more preferable that the embossing pattern 12 is provided on the ply on the surface 1a side of the kitchen towel 1x.

[0046] 2 and 3 are diagrams showing an example of the embossing pattern 12 of the kitchen towel 1x of this embodiment. The embossing pattern 12 preferably includes radial embossments 13 and closed-ring structure embossments 14, and the radial embossments 13 and the closed-ring structure embossments 14 are alternately arranged at equal intervals. The inclusion of the radial embossments 13 and the closed-ring structure embossments 14 improves the water absorbency of the kitchen towel 1x. Furthermore, the kitchen towel 1x has an appropriate paper thickness, which allows for easy wrapping around the core. Furthermore, the compact design makes the core 1d less likely to be crushed.

[0047] The lines forming the embossed pattern 12 may be solid, broken, dashed, or dotted, and may be of any thickness. Among these, solid lines are preferred because they provide good water absorption, good winding around the core, compactness, and resistance to crushing of the core 1d.

[0048] (radial embossing) The overall shape of the radial embossments 13 is not particularly limited, but it is preferable that the embossed pattern 12 has a plurality of linear embossments extending from the center outward or linear embossments. When the embossed pattern 12 includes the radial embossments 13, the water absorption, winding around the core 1d, compactness, and resistance to crushing of the core 1d are improved.

[0049] (closed ring structure embossed) The closed-ring structure embossment 14 is not particularly limited in overall shape, as with the radial embossment 13, but preferably has a linear or geometric embossment provided in the center and a geometric embossment surrounding it to form a closed ring on the outside. When the embossment pattern 12 includes the closed-ring structure embossment 14, the water absorbency, wrapping around the core 1d, compactness, and resistance to crushing of the core 1d are improved.

[0050] (embossing size) The lower limit of the size (area) of the embossed pattern 12 including one radial embossment 13 and one closed-ring structure embossment 14 is 16 cm 2 More than 28cm is preferable. 2 More than 45cm is preferable. 2More preferably, the upper limit is 250 cm 2 Less than 180cm is preferable 2 Less than 110cm is preferable. 2 More preferably, the size of the embossed pattern 12 is 16 cm 2 Less than 250cm 2 If it exceeds this value, the paper thickness is likely to fluctuate, and winding onto the core 1d will be poor.

[0051] The size of the embossed pattern 12 is determined by calculating the area of ​​a rectangle E that includes (circumscribes) all of the embossed pattern 12, as shown in Figure 3. The sizes of the long and short sides of this rectangle E can be changed as appropriate depending on the size of the embossed pattern 12 (radial embossments 13 and closed-ring structure embossments 14).

[0052] (embossed area ratio) The lower limit of the embossed area ratio of the kitchen towel 1x (hereinafter simply referred to as "embossed area ratio") is preferably 4% or more, more preferably 6% or more, and even more preferably 8% or more. The upper limit of the embossed area is preferably 30% or less, more preferably 25% or less, and even more preferably 15% or less. If the embossed area ratio is less than 4%, the paper thickness is likely to fluctuate, making it difficult to wrap the kitchen towel 1x around the core 1d. If the embossed area ratio exceeds 30%, the kitchen towel 1x becomes stiff and difficult to wrap around the core 1d.

[0053] The embossed area ratio is determined by measuring the surface 1a side (the outer surface of the roll) of the kitchen towel 1x, which corresponds to the top 10% of the roll 1, with a ruler or tape measure, measuring the area, and converting it into a ratio per unit area (area ratio). When the embossing is difficult to see with the naked eye or when the embossing width is narrow, it is preferable to measure the area using a microscope (KEYENCE Corporation VR-6000). The top 10% of the roll 1 refers to the outermost 10% of the roll 1 (the portion closest to the roll surface). For example, if the roll 1 is 30 m long, this refers to the first 3 m of use.

[0054] The above area ratio is calculated by the following procedure. (1) Inside a rectangle E that includes one embossing pattern 12 as shown in Figure 3, for embossments that are 0.1 mm or more and 4 mm or less in thickness and 5 mm or more in length, measure the total length by adding up the embossment lengths, and calculate the area of ​​the embossment by multiplying the total length (mm) by the thickness (mm). (2) If the thickness of the embossments is not uniform in (1), calculate the area of ​​each embossment by multiplying the length (mm) of the embossment by the thickness (mm), and then add up the areas of all the embossments. (3) The ratio of the embossed area to the area of ​​rectangle E in Figure 3 (length (mm) x width (mm)) is defined as (total embossed area / area of ​​rectangle E) x 100, which is the embossed area ratio (%). (4) If it is difficult to determine the embossed area ratio, the area ratio of the convex parts of the embossing roll used in the embossing process can be considered as the area of ​​one sheet of kitchen towel 1x.

[0055] The size of one side of this rectangle E can be changed as appropriate depending on the size of the embossed pattern. Furthermore, if the rectangle that contains all of the embossed patterns contains an embossed pattern adjacent to an embossed pattern contained within the rectangle, the length of the adjacent embossed pattern is also measured and included in the total length. If the size of one side of rectangle E cannot be clearly determined depending on the embossed pattern, the size of rectangle E is set to 10 cm x 10 cm, and the total length of the embossments contained within this rectangle E is measured. The total length is determined using the method described above.

[0056] (embossing depth) The lower limit of the embossing depth on the front side of the kitchen towel 1x (hereinafter simply referred to as "embossing depth") is preferably 0.06 mm or more, more preferably 0.10 mm or more, and even more preferably 0.14 mm or more. The upper limit of the embossing depth is preferably 1.05 mm or less, more preferably 0.55 mm or less, and even more preferably 0.35 mm or less. If the embossing depth is less than 0.06 mm, the ply will be easily peeled off, making it difficult to wrap the kitchen towel 1x around the core 1d. If the embossing depth exceeds 1.05 mm, the surface roughness of the back side of the kitchen towel 1x will increase, making it difficult to wrap the kitchen towel 1x around the core 1d.

[0057] The embossing depth is measured using a microscope. The microscope used can be a Keyence One-Shot 3D Measuring Macroscope VR-3100. The Keyence VR-H1A software can be used to observe, measure, and analyze microscope images. Measurement conditions are a magnification of 25x and a field of view of 12mm x 9mm. The measurement magnification and field of view can be changed as appropriate depending on the desired size of the embossing.

[0058] Figure 5 shows a height profile on the XY plane taken with a microscope, with the height of the kitchen towel 1x surface represented by shading. The linear areas in Figure 5 that are shaded differently from the surrounding area represent individual embossments. The depth of the embossment is determined by measuring the height difference of the embossment using the microscope described above. The measurement is performed on the surface 1a side of the kitchen towel 1x. Furthermore, when measuring, three wraps of kitchen towel 1x are removed from the kitchen towel roll 1, and the fourth wrap of kitchen towel 1x is used to measure the product ply in sheet form. Furthermore, if there are perforations 1c, these are also avoided when measuring.

[0059] First, a line segment AB is drawn as shown in Figure 5 to obtain the height profile shown in Figure 6. Line segment AB should be drawn across the embossments. Line segment AB is drawn in the width direction (CD) of the kitchen towel 1x. However, if the spacing between embossments is narrow, e.g., 2 mm or less, resulting in a low height of the convex portions described below, the line segment may be drawn diagonally or in the machine direction. The height profile is a (measured) cross-sectional curve S that represents the surface irregularities of the actual kitchen towel 1x sample. However, it also contains noise (steep peaks due to fiber clumps, whisker-like fibers, or fiber-free areas on the surface of the kitchen towel 1x). Therefore, when calculating the height difference of the irregularities, it is necessary to remove such noise peaks.

[0060] Therefore, the (measured) cross-sectional curve S in Figure 6 was smoothed using the weighted average radio button filter size of ±12 to obtain the cross-sectional curve W in Figure 7. Note that smoothing using the weighted average radio button filter can be achieved automatically using the analysis software described above. Then, in the graph shown in Figure 7, the average of the maximum values ​​on the vertical axis of the convex portion H1 and the convex portion H2 adjacent to the convex portion H1 was calculated, and the minimum value on the vertical axis of the concave portion D1 sandwiched between the convex portions H1 and H2 was determined. The value obtained by subtracting the minimum value from the average of the maximum values ​​thus obtained was used as the provisional emboss depth. Then, as shown in Figure 7, similar measurements were performed at two consecutive locations on the cross-sectional curve (the concave portion D1 and the concave portion D2 sandwiched between the convex portions H3 and H4) (two consecutive measurement results were obtained at this point). Next, the roll 1 is rotated three times by 90 degrees in the machine direction of the kitchen towel 1x, and the same measurement as above is carried out at each position (for a total of four measurement positions in the machine direction), and the average value of the total eight positions (2 x 4) is finally adopted as the embossing depth. Note that while visually checking the embossed areas in Figure 5, the height profile in Figure 6 is checked to determine the concave and convex areas.

[0061] Since the kitchen towel 1x of the present invention has a pattern of protrusions and recesses derived from the papermaking process, which is different from the embossed pattern, there is variation in the height of the protrusions on either side of the recess. Therefore, if the difference in the vertical axis between the protrusions sandwiching the recess (for example, protrusions H3 and H4 sandwiching recess D2) is 0.2 mm or more, measurements are taken at a location that avoids that part.

[0062] (Embossed pattern arrangement angle) The arrangement angle of adjacent identical patterns in the embossed pattern 12 (hereinafter also referred to as the "embossed pattern arrangement angle") is preferably 20° or more, preferably 25° or more, and more preferably 30° or more, relative to the CD direction of the kitchen towel 1x. It is also preferably 80° or less, preferably 70° or less, and more preferably 60° or less. If the arrangement angle of the embossed pattern 12 is less than 20° or more than 80°, the kitchen towel 1x is prone to wrinkling during processing, resulting in poor winding around the core.

[0063] The arrangement angle of the embossed pattern 12 is measured by the following method. (1) Select one embossment to be used as the measurement standard and determine the reference point of this embossment. For example, as shown in Figure 4, place the kitchen towel 1x so that the MD direction (Y direction) is vertical and the CD direction (X direction) is horizontal. Then, select any closed-ring structure embossment 14A (hereinafter referred to as "embossment 14A") in the center of the kitchen towel 1x, and set its center point as reference point 14a. (2) Two embossments adjacent to the reference embossment on the left and right in the CD direction are identified, and measurement points for these embossments are determined. As shown in Figure 4, a straight line passing through reference point 14a and parallel to the CD direction is drawn and designated as reference line 14x. The left closed-ring structure embossment and the right closed-ring structure embossment, which are located above reference line 14x and closest to reference point 14a in the CD direction, are designated as 14B and 14C, respectively, and their center points are designated as measurement points 14b and 14c. (3) Draw an auxiliary line passing through the reference point and the measurement point, and measure the angle between the reference line and the auxiliary line. As shown in Figure 4, an auxiliary line 14y passing through reference point 14a and measurement point 14b, and an auxiliary line 14z passing through reference point 14a and measurement point 14c are drawn. Then, the angle θ1 formed by reference line 14x and auxiliary line 14y, and the angle θ2 formed by reference line 14x and auxiliary line 14z are measured with a protractor and are defined as the arrangement angles. In Figure 4, θ1 is 35° and θ2 is 55°. Note that when θ exceeds 90°, the angle obtained by subtracting θ from 180° is defined as the arrangement angle. For example, when θ is 120°, the angle is defined as 60° (= 180° - 120°).

[0064] (proportion of linear embossed area) The proportion of linear embossed portions 12a in the embossed pattern 12 is preferably 20% or more. If the proportion is less than 20%, the water absorbency of the kitchen towel 1x will be poor. The proportion of linear embossed portions 12a in the embossed pattern 12 is more preferably 50% or more, and even more preferably 90% or more.

[0065] In this case, the linear embossed portion 12a refers to an embossment included in the embossed pattern 12 that has a thickness of 0.1 mm to 4 mm and a length of 5 mm or more.

[0066] The proportion of the linear embossed portion 12a is calculated as follows: First, an arbitrary 100 mm x 100 mm area on the surface of the kitchen towel 1x on which the embossed pattern 12 is formed is divided into 10 mm squares. Then, the proportion of the linear embossed portion 12a is calculated using the following formula: Proportion (%) of linear embossed portion 12a = (number of squares including linear embossed portion 12a) ÷ (number of squares including linear embossed portion 12a + number of squares including embossments other than linear embossed portion 12a) × 100

[0067] It should be noted that "a square including an embossment other than the linear embossed portion 12a" refers to a square that does not satisfy the conditions of the linear embossed portion 12a among the radial embossment 13 or the closed ring structure embossment 14. In addition, when one square includes both the linear embossment 12a and the dot embossment, the square is considered to be the embossed square with the larger occupancy.

[0068] (Embossed on the back) There is no particular restriction on whether the ply on the back surface 1b of the kitchen towel 1x has an embossed pattern 12, as long as it has irregularities resulting from the papermaking process that are different from the embossed pattern 12, but it is preferable that the back surface 1b not be embossed. If the back surface 1b has an embossed pattern, the surface roughness of the surface in contact with the core 1d increases, making it difficult to wrap the back surface 1b around the core 1d.

[0069] (seat length) The lower limit of the sheet length between adjacent perforations 1c of kitchen towel 1x (length in the Y direction shown in FIG. 1) is preferably 100 mm or more, more preferably 130 mm or more, and even more preferably 150 mm or more. The upper limit of the sheet length is preferably 250 mm or less, more preferably 230 mm or less, and even more preferably 210 mm or less. If the sheet length is less than 100 mm, the absorbency of kitchen towel 1x will be poor, and if it exceeds 250 mm, the absorbency of kitchen towel 1x will be higher than necessary.

[0070] (sheet width) The lower limit of the sheet width (hereinafter also referred to as "roll width") (W shown in FIG. 1) of the kitchen towel 1x is preferably 150 mm or more, more preferably 200 mm or more, and even more preferably 250 mm or more. The upper limit is preferably 380 mm or less, more preferably 340 mm or less, and even more preferably 300 mm or less. If the sheet width (W) is less than 150 mm, the absorbency of the kitchen towel 1x will be poor, and if it exceeds 380 mm, the absorbency of the kitchen towel 1x will be higher than necessary.

[0071] (DMDT) The lower limit of the dry machine direction tensile strength (DMDT) of the product ply of the kitchen towel 1x according to JIS P 8113 is preferably 6 N / 25 mm or more, more preferably 7 N / 25 mm or more, and even more preferably 8 N / 25 mm or more. The upper limit of DMDT is preferably 13 N / 25 mm or less, more preferably 12 N / 25 mm or less, and even more preferably 11 N / 25 mm or less. If the DMDT is less than 6 N / 25 mm, the basis weight of the kitchen towel 1x will be low and the absorbency will be poor. If the DMDT is more than 13 N / 25 mm, the kitchen towel 1x will be stiff and difficult to wrap around the core 1d.

[0072] (DCDT) The lower limit of the dry cross direction tensile strength (DCDT) of the product ply of the kitchen towel 1x according to JIS P 8113 is preferably 6 N / 25 mm or more, more preferably 7 N / 25 mm or more, and even more preferably 8 N / 25 mm or more. The upper limit of DCDT is preferably 13 N / 25 mm or less, more preferably 12 N / 25 mm or less, and even more preferably 11 N / 25 mm or less. If the DCDT is less than 6 N / 25 mm, the basis weight of the kitchen towel 1x will be low and the absorbency will be poor. If the DCDT is more than 13 N / 25 mm, the kitchen towel 1x will be stiff and difficult to wrap around the core 1d.

[0073] The DMDT and DCDT of one kitchen towel are measured in accordance with JIS P 8113 on the part of one kitchen towel that does not include perforation 1c.

[0074] (DGMT) The lower limit of the DGMT (Dry Geometric Tensile Strength) of the product ply of the kitchen towel 1x is preferably 6N / 25mm or more, more preferably 7N / 25mm or more, and even more preferably 8N / 25mm or more. The upper limit of the DGMT is preferably 13N / 25mm or less, more preferably 12N / 25mm or less, and even more preferably 11N / 25mm or less. If the DGMT is less than 6N / 25mm, the basis weight of the kitchen towel 1x will be low and the absorbency will be poor. If the DGMT is more than 13N / 25mm, the kitchen towel 1x will be stiff and difficult to wrap around the core 1d.

[0075] DGMT can be calculated by taking the geometric mean of DMDT and DCDT. DGMT = (DMDT × DCDT) 1 / 2

[0076] (Water absorption <unit area>) The water absorption per unit area of ​​one kitchen towel (hereinafter simply referred to as "water absorption <unit area>") is 300g / m 2 More than 600g / m 2 The water absorption capacity (unit area) is 300g / m 2 If it is less than 600g / m, the absorbency will be poor. 2 If it exceeds this limit, the basis weight of the kitchen towel 1x will be too high and it will be difficult to wrap the kitchen towel 1x around the core 1d. The lower limit of the water absorption capacity (unit area) is 350g / m 2 More than 380g / m 2 More preferably, the upper limit is 550 g / m 2 Preferably less than 500 g / m 2 The following is more preferred:

[0077] (Water absorption <unit mass>) The water absorption per unit mass of the kitchen towel 1x (hereinafter simply referred to as "water absorption <unit mass>") is preferably 7 g / g or more and 14 g / g or less. If the water absorption <unit mass> is less than 7 g / g, the water absorption is poor. If the water absorption <unit mass> is more than 14 g / g, the paper thickness or specific volume becomes high, making it difficult to wind the kitchen towel 1x around the core 1d. In addition, the winding becomes tight, making the core 1d more likely to collapse. The lower limit of the water absorption <unit mass> is more preferably 8 g / g or more, and even more preferably 9 g / g or more. The upper limit is more preferably 13 g / g or less, and even more preferably 12 g / g or less.

[0078] The water absorption of 1 kitchen towel in a dry state is measured according to the following method. (1) A two-ply kitchen towel 1x is taken and cut using a square template with one piece measuring 76 mm to prepare a rectangular test piece 20 (see FIG. 9) with one side measuring 76 mm. (2) After measuring the mass of the test piece 20 before water absorption with an electronic balance, the test piece 20 is set in a holder 21 (a jig that fixes three points of the test piece 20, the jig being made of a metal that does not absorb water). (3) Distilled water is poured into a commercially available tray to a depth of 2 cm, and the test piece 20 set in the holder 21 is immersed in the distilled water for 2 minutes. (4) After immersion for 2 minutes, the test piece 20 is removed from the distilled water together with the holder 21, and as shown in Figure 9, the holder 21 and the test piece 20 are hung on a rod placed in an empty water tank with the corner 20a facing up, the lid of the water tank is closed, and the test piece is left for 5 minutes. (5) Then, the holder 21 and the test piece 20 are taken out of the water tank, the holder 21 is removed, and the mass of the test piece 20 is measured using an electronic balance. (6) The water absorption amount <unit area> is calculated from the change in mass of the test piece 20 before and after immersion in distilled water, and is calculated as the amount of distilled water absorbed per unit area of ​​the test piece 20 (g of water / sheet m 2 , 1m 2 Per. Abbreviated as g / m 2 ) is calculated. (7) Water absorption <unit mass> is the amount of water absorption per unit area (g of water / sheet m 2) by the basis weight of the product ply of the test piece 20. Specifically, the water absorption per unit area (water g / sheet m 2 ) ÷ Basis weight (sheet g / sheet m 2 ) = Water absorption amount <unit mass> (g of water / g of sheet, per 1g. Abbreviated as g / g). (8) Measurements are carried out five times for each sample, and the average value is used.

[0079] If the kitchen towel is a three-ply towel, it is preferable to measure it as a three-ply towel using the same procedure as for a two-ply towel. This measurement is performed according to JIS P 8111 at a temperature of 23±1°C and a humidity of 50±2%. The distilled water is kept at 23±1°C.

[0080] (Surface roughness of the back of the sheet <sq1>) The root mean square height of the surface roughness of the kitchen towel 1x on the surface in contact with the core 1d (hereinafter simply referred to as the "surface roughness of the back surface of the sheet" or "Sq1") is preferably 38 μm or more and 125 μm or less. If the surface roughness of the back surface is less than 38 μm, the water absorbency of the kitchen towel 1x will be poor. If the surface roughness of the back surface 1b of the sheet exceeds 125 μm, the unevenness of the kitchen towel 1x will increase, increasing the paper thickness or specific volume, making it difficult to wrap the kitchen towel 1x around the core 1d. Alternatively, the wrap will be too tight, making the core 1d more likely to be crushed. The lower limit of the surface roughness is more preferably 50 μm or more, and even more preferably 58 μm or more. The upper limit is more preferably 95 μm or less, and even more preferably 83 μm or less.

[0081] Here, "the surface of kitchen towel 1x that contacts core 1d" refers to back surface 1b of kitchen towel 1x in Figure 1. For example, if the product has two plies, this refers to the surface of back surface 1b that contacts core 1d when kitchen towel 1x is wound around core 1d, rather than the front surface 1a (outer peripheral surface). Note that the surface roughness of back surface 1b of kitchen towel 1x can be changed as needed depending on the size of the irregularities in the fabric used in TAD.

[0082] The surface roughness (Sq1) of the backside of the sheet is measured using a microscope in the state of a 2-ply or 3-ply kitchen towel sheet. A microscope manufactured by KEYENCE, product name "One-Shot 3D Shape Measuring Instrument VR-6000," can be used. A software for observing, measuring, and analyzing microscope images, product name "Analysis Application VR-6000," manufactured by KEYENCE, can be used. The measurement conditions are a magnification of 12x and a field of view area of ​​24mm x 18mm. The measurement magnification and field of view area may be changed as appropriate.

[0083] Filters are set for the obtained image (Figure 8). Specifically, by setting an S-filter (low-pass filter), components with a scale smaller than the cutoff wavelength are removed from the image. By setting an L-filter (high-pass filter), components with a scale larger than the cutoff wavelength are removed from the image. Here, the S-filter is set to 500 μm and the L-filter to 8 mm. By selecting the S-filter and L-filter, the root-mean-square height Sq is automatically calculated.

[0084] The measurement method is as follows. (1) For the sample, remove three wraps of kitchen towel 1x from roll 1, and cut two sheets from the fourth wrap of kitchen towel 1x. For example, if the sheet length between perforation 1c and the adjacent perforation 1c is 178 mm, the length in the MD direction will be 356 mm. (2) Measurements shall be taken on the product ply, avoiding perforations 1c if any. (3) Spread two sheets of the sheet so that the CD direction is horizontal and the MD direction is vertical as shown in Figure 2, and measure two points approximately 5 cm below the top edge (CD direction) on an approximately straight line in the CD direction (X direction in Figure 2). (4) Next, measure two points approximately 10 cm below, 20 cm below, and 30 cm below the top edge (CD direction) on an approximately straight line in the CD direction (X direction in Figure 2) in the same way as in (3). (5) The average value of the total eight locations (2 x 4) measured in (3) and (4) is finally adopted as the root mean square height Sq1.

[0085] <Core (paper tube)> The paper tube (hereinafter also referred to as "core") (1d in FIG. 1) that is present in the center of the roll 1 and around which the kitchen towel 1x is wound into a roll is preferably a cylindrical paper tube.

[0086] (Core material) The material (paper) used for the core 1d preferably contains bleached hardwood kraft pulp (LBKP) and bleached softwood kraft pulp (NBKP) as pulp fibers. For example, the content ratio of LBKP to NBKP is preferably 30:70 to 100:0, more preferably 50:50 to 100:0, and even more preferably 70:30 to 100:0. If the LBKP content is less than 30% by mass, the surface roughness of the core 1d increases, making it difficult to wrap the kitchen towel 1x around the core 1d.

[0087] It is also preferable that the paper used for the core 1d is made of a plurality of overlapping sheets. If the core 1d is made of a single sheet of paper, the core 1d becomes thin and easily crushed. It is preferable that two sheets of paper are overlapped.

[0088] (core mass) The lower limit of the mass of the core 1d is preferably 10 g or more, more preferably 12 g or more, and even more preferably 14 g or more. The upper limit is preferably 25 g or less, more preferably 20 g or less, and even more preferably 17 g or less. If the mass of the core is less than 10 g, the core 1d may be crushed when wrapping the kitchen towel 1x around the core 1d, making it difficult to wrap. If the mass of the core is more than 12 g, the surface roughness of the core 1d may be poor (high and rough), making it difficult to wrap.

[0089] (Apparent basis weight of core) The lower limit of the apparent basis weight of the core 1d is 250 g / m 2 More than 300g / m 2 More preferably, 380 g / m 2 More preferably, the upper limit is 650 g / m 2 Preferably less than 520 g / m 2 Less than 450 g / m is more preferable. 2 More preferably, the core 1d has an apparent basis weight of 250 g / m 2 If the apparent basis weight of the core 1d is less than 650 g / m, the core 1d will be crushed when wrapping the kitchen towel 1x around the core 1d, making it difficult to wrap the kitchen towel 1x around the core 1d. 2 If the value exceeds this, the surface roughness of the core 1d will be poor (the value will be high and rough), making it difficult to wind. The paper used for the core 1d can be subjected to a calendering process to adjust the root mean square height of the surface roughness of the core 1d, as described below.

[0090] The apparent basis weight of the core 1d is expressed as (mass of the core) ÷ (external surface area of ​​the core). The mass and external surface area of ​​the core are the mass and external surface area of ​​the core converted per roll width. For example, if the mass of the core per roll width of 281 mm is 16 g and the outer diameter of the core is 44 mm, the apparent basis weight of the core = 16 ÷ {(3.14 × 44 mm / 1000) × (281 mm / 1000)} = 412 g / m 2 Here, core 1d is usually made by gluing two sheets of core base paper together with adhesive or the like, and there are some areas where the two sheets of core base paper overlap, making it thicker, so it is different from a simple sheet rolled up, and therefore the "apparent" basis weight is used.

[0091] (Core surface roughness <sq2>) The root mean square height of the surface roughness of the surface of the core 1d that comes into contact with the kitchen towel 1x (hereinafter simply referred to as "core surface roughness" or "Sq2") is 8 μm or less. If the surface roughness of the core exceeds 8 μm, it becomes difficult to wind the kitchen towel 1x around the core 1d. The upper limit of the surface roughness of the core is preferably 6 μm or less, and more preferably 5 μm or less. Here, "the surface of the core 1d that comes into contact with the kitchen towel 1x" refers to the surface that comes into contact with the kitchen towel 1x when the kitchen towel 1x is wound around the core 1d.

[0092] The surface roughness (Sq2) of the core 1d is measured using a microscope while keeping the shape of the core 1d. Measurements are also made while avoiding areas where glue is attached to the core 1d. The measurement microscope used is the KEYENCE One-Shot 3D Shape Measuring Instrument VR-6000. The KEYENCE Analysis Application VR-6000 software can be used to observe, measure, and analyze microscope images. Measurement conditions are 38x magnification and a field of view of 8mm x 6mm.

[0093] First, place core 1d on the measurement stage and use the autofocus function to focus on the top surface of core 1d (the focus is adjusted automatically) before measuring. As the shape of the core is not flat, the obtained image is subjected to surface shape correction (cylindrical correction). With cylindrical correction, correction is performed automatically by setting (inputting) the value of the outer diameter of core 1d.

[0094] Next, set the filters. Specifically, by setting an S-filter (low-pass filter), components with a scale smaller than the cutoff wavelength are removed from the image. By setting an L-filter (high-pass filter), components with a scale larger than the cutoff wavelength are removed from the image. Here, the S-filter is not set, and the L-filter is set to 5 mm. By selecting the S-filter and L-filter, the root mean square height Sq is calculated automatically.

[0095] The sample to be measured is prepared by removing the kitchen towel 1x from the kitchen towel roll 1, taking out the core 1d, and measuring the surface of the core 1d. Two points are measured in the axial direction of the core (the X direction in Figure 1). Two other cores are then measured in the same way, and the average value of a total of six points (three cores x two points) is finally adopted as the root mean square height Sq2.

[0096] (Sq1 × Sq2) The value expressed by the product of the "surface roughness of the back surface of the sheet (Sq1)" and the "surface roughness of the core (Sq2)" (hereinafter simply referred to as "Sq1 x Sq2") is preferably 100 or more and 530 or less. If this value (Sq1 x Sq2) is less than 100, the core 1d may be easily crushed, and if it exceeds 530, it becomes difficult to wrap the kitchen towel 1x around the core 1d. The lower limit of this value (Sq1 x Sq2) is more preferably 120 or more, and even more preferably 140 or more. The upper limit is more preferably 430 or less, and even more preferably 340 or less.

[0097] (Core outer diameter) The lower limit of the outer diameter (DI shown in FIG. 1) of the core 1d (hereinafter simply referred to as "core outer diameter") is preferably 28 mm or more, more preferably 33 mm or more, and even more preferably 40 mm or more. The upper limit of the core outer diameter is preferably 58 mm or less, more preferably 53 mm or less, and even more preferably 46 mm or less. If the core outer diameter is less than 28 mm or more than 58 mm, it becomes difficult to wrap the kitchen towel 1x around the core 1d.

[0098] The core outer diameter is measured using a diameter rule manufactured by Muratec KDS Co., Ltd. Three kitchen towel rolls 1 are measured and the measurement results are averaged.

[0099] <Kitchen towel roll> The kitchen towel roll 1 obtained by winding the kitchen towel 1x around the core 1d in a roll shape preferably has the following characteristics.

[0100] (roll diameter) The lower limit of the winding diameter (DR shown in FIG. 1) of the roll 1 is preferably 127 mm or more, more preferably 135 mm or more, and even more preferably 140 mm or more. The upper limit of the winding diameter is preferably 175 mm or less, more preferably 165 mm or less, and even more preferably 157 mm or less. If the winding diameter is less than 127 mm, the roll density will be high and the core 1d will be easily crushed if the basis weight and winding length of the kitchen towel 1x are within a certain range. If the winding diameter is more than 175 mm, the roll density will be low and compactness will be poor if the basis weight and winding length of the kitchen towel 1x are within a certain range.

[0101] The roll diameter is measured using a diameter rule manufactured by Muratec KDS Co., Ltd. Three rolls 1 are measured and the measurement results are averaged.

[0102] (Volume length) The winding length of the roll 1 is preferably 18 m or more and 45 m or less. If the winding length is less than 18 m, the roll density will be low and compactness will be poor. If the winding length exceeds 45 m, the roll density will be high and the core 1d will be more likely to be crushed. The lower limit of the winding length is more preferably 20 m or more, and even more preferably 24 m or more. The upper limit of the winding length is more preferably 40 m or less, and even more preferably 35 m or less.

[0103] The roll length is measured as follows. First, measure the length of 10 sheets of kitchen towel 1x between perforation 1c on roll 1 and the adjacent perforation 1c. Then, measure the number of sheets on roll 1, and calculate the roll length proportionally from the length of 10 sheets and the number of sheets. For example, if the length of 10 sheets is 1.80m and there are 150 sheets, the roll length is 1.80m x (150 / 10) = 27m. If kitchen towel roll 1 does not have perforations, measure the roll length.

[0104] (winding density) The lower limit of the winding density of roll 1 is 0.20 m / cm 2 More than 0.24m / cm is preferable. 2 More preferably, 0.30 m / cm or more 2 The upper limit of the winding density is 0.56 m / cm. 2 Preferably less than 0.50m / cm 2 Less than 0.45m / cm is more preferable. 2 More preferably, the winding density is 0.20 m / cm 2 If the winding density is less than 0.56 m / cm, the water absorbency of the kitchen towel 1x will be poor, and the basis weight will be too high to wind it around the core. In addition, the compactness of the roll 1 will be poor. 2 If the temperature exceeds this, the kitchen towel 1x will become stiff and difficult to wrap around the core 1d. Also, the wrap will become too tight, making the core 1d more likely to collapse.

[0105] The winding density is expressed as (winding length x number of plies) ÷ (cross-sectional area of ​​the roll). The cross-sectional area of ​​the roll is expressed as {cross-sectional area of ​​the roll outer diameter (winding diameter DR) - (cross-sectional area of ​​the core outer diameter DI)}. For example, in the case of a winding length of 27 m, 2 plies, a winding diameter DR of 150 mm, and a core outer diameter DI of 39 mm, the winding density = (27 m x 2) ÷ {3.14 x (150 mm ÷ 2 ÷ 10) 2 -3.14×(39mm÷2÷10) 2 }=0.33m / cm 2 This becomes:

[0106] (Rolling hardness) The lower limit of the tightness of the roll 1 (hereinafter simply referred to as "tightness") is preferably 1.0 mm or more, more preferably 1.5 mm or more, and even more preferably 2.0 mm or more. The upper limit of the tightness is preferably 5.0 mm or less, more preferably 4.0 mm or less, and even more preferably 3.0 mm or less. If the tightness is less than 1.0 mm, the roll 1 will be less compact. If the tightness exceeds 5.0 mm, the roll will be tightly wound and the core 1d will be more likely to be crushed. Note that "tightness" means the tightness of the roll 1 when held in the hand.

[0107] The winding hardness of the roll 1 is measured using a compression tester (handy compression tester KES-G5 manufactured by Kato Tech Co., Ltd.) as follows: The direction parallel to the axial direction of the roll 1 is defined as the height direction, and the direction perpendicular to the rotation axis of the roll 1 is defined as the radial direction.

[0108] (1) Place roll 1 horizontally on the table of the testing machine so that the axial direction of roll 1 is horizontal. (2) A KES-G5 compression element (contact area 2.0 cm) was placed at the "axial center" of Roll 1. 2 ) is pressed from above in the radial direction at a speed of 10 mm / min. The "axial center" of roll 1 is determined by measuring the roll width (W) with a metal ruler or tape measure, and determining the position where the measurement value is 1 / 2, and then pressing the compression element into this position. (3) The pressure with which the compressor presses the roll is 5 gf / cm 2 The indentation depth when the pressure is 150gf / cm 2 The indentation depth at this time is T m As, (T m -T0) is measured as "rolling hardness." (4) Next, the roll 1 is rotated 90 degrees in the circumferential direction around its axis as the axis of rotation, and the pressing depth T m and T0 are measured, and T m and T0 (T m -T0). (5) For the measurement, measure each of the three rolls 1 twice (at two angles) as described above, and the average of the measurement results for a total of six times (= two times / roll x 3 rolls) is the roll hardness.

[0109] (Roll mass <without core>) The lower limit of the roll mass of the roll 1 per 280 mm of roll width, excluding the core 1d (hereinafter simply referred to as "roll mass (without core)"), is preferably 200 g or more, more preferably 240 g or more, and even more preferably 260 g or more. The upper limit of the roll mass (without core) is preferably 550 g or less, more preferably 490 g or less, and even more preferably 450 g or less. If the roll mass (without core) is less than 200 g, the kitchen towel 1x will have poor absorbency, a low roll density, and poor compactness. If the roll mass (without core) exceeds 550 g, the kitchen towel 1x will become stiff and difficult to wind around the core 1d. Furthermore, the roll will be tightly wound, making the core 1d more likely to be crushed.

[0110] Roll mass (without core) is the mass per 280mm of roll width, excluding the core (paper tube) 1d of the kitchen towel roll 1. If the roll width is not 280mm, convert to the mass per 280mm by proportional calculation.

[0111] (roll density) The roll density of Roll 1 is 0.04 g / cm 3 More than 0.13g / cm 3 The roll density is 0.04 g / cm or less. 3 If the roll density is less than 0.13 g / cm, the absorbency of the kitchen towel 1x will be poor and the compactness of the roll 1 will be poor. 3 If the density exceeds 100%, the kitchen towel 1x will become stiff and difficult to wrap around the core 1d. In addition, the roll will become too tight, making the core 1d more likely to be crushed. The lower limit of the roll density is 0.05 g / cm 3 More than 0.06 g / cm is preferable. 3 The upper limit of the roll density is preferably 0.11 g / cm. 3 Preferably less than 0.09 g / cm 3 The following is more preferred:

[0112] Roll density is expressed as (roll mass) ÷ (roll volume). Roll mass is the mass of a kitchen towel roll 1 per 280 mm of roll width. Roll volume is expressed as [{cross-sectional area of ​​the roll's outer diameter (winding diameter DR)} - (cross-sectional area of ​​the core's outer diameter DI)] × roll width (converted per 280 mm). For example, if the roll mass (excluding the core) per 280 mm of roll width is 382 g, the winding diameter DR is 150 mm, and the core's outer diameter DI is 39 mm, then roll density = 382 g ÷ [{3.14 × (150 mm ÷ 2 ÷ 10) 2 -3.14×(39mm÷2÷10) 2 }×(280mm÷10)]=0.08g / cm 3 This becomes:

[0113] <Kitchen towel roll manufacturing method> The kitchen towel roll 1 can be produced, for example, in the following order: (1) papermaking and creping, (2) embossing and bonding, and (3) roll winding. Note that the TAD papermaking method is preferably used in the production (papermaking) process of the kitchen towel 1x.

[0114] In the papermaking process (1), it is preferable that a concave-convex pattern derived from the papermaking process (fabric), different from the embossed pattern described above, is applied to the kitchen towel 1x. By having this concave-convex pattern, the water absorption capacity of the kitchen towel 1x can be further increased.

[0115] "Derived from the papermaking process" means that, during the papermaking process for kitchen towel 1x, a concave-convex pattern is imparted between the head box 41 of the papermaking machine and the outlet of the Yankee dryer 46. Specifically, in a portion of the papermaking process shown in FIG. 10, pulp slurry 40a is sprayed (supplied) from the head box 41 between the first fabric (forming fabric) 42 and the second fabric (concave-convex fabric) 43, and is drawn onto the second fabric (concave-convex fabric) 43 by the forming roll 44, forming a wet paper 40b. Next, the wet paper 40b is dried together with the second fabric (concave-convex fabric) 43 in a through-air dryer 45, resulting in the formation of concave-convex patterns in the dried sheet 40c. Note that, although FIG. 10 shows the through-air dryer 45 equipped with two units, it may also be equipped with only one unit. Also, although a Yankee hood is depicted on the Yankee dryer 46, the hood may be omitted. Crepe may be imparted in the Yankee dryer 46.

[0116] The texture pattern can also be adjusted by changing the fabric pattern (fine or coarse). Selecting a finer texture pattern reduces water absorption. On the other hand, selecting a coarser texture pattern makes it difficult to wrap the kitchen towel 1x around the core 1d, and the increased paper thickness results in a tighter wrap, making the core more susceptible to crushing. Therefore, a good balance is important when selecting the texture pattern.

[0117] As described above, according to this embodiment, even if the kitchen towel has an uneven surface and is highly absorbent, it is possible to provide a kitchen towel roll that is compact, is less likely to collapse, and can be easily wound around the core.

[0118] Although the present invention has been described above using embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. Furthermore, it is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention. [Example]

[0119] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the examples shown below.

[0120] The kitchen towel rolls of Examples 1 to 19 and Comparative Examples 1 to 9 shown in Tables 1 and 2 were manufactured through the following processes: (1) papermaking and creping, (2) embossing and laminating, and (3) roll winding. The kitchen towel rolls of all Examples and Comparative Examples were measured for the above-mentioned parameters and evaluated as follows. Note that parameters other than those evaluated below were measured according to the standards or measurement methods described above.

[0121] 1. Kitchen towel sheet absorbency A sensory evaluation of the "water absorbency" of manufactured kitchen towels was conducted by 30 monitors. A single sheet cut along a perforation was used to wipe away 15g of water scattered on a table from the outermost, central, and innermost periphery of a kitchen towel roll. The monitors evaluated the sheets in the same way as they normally would use kitchen towels, choosing either "the sheet has excellent water absorbency" or "the sheet has poor water absorbency," and the evaluation was made on a four-point scale depending on the number of people who selected "the sheet has poor water absorbency." The evaluation criteria are as follows: ◎: 0-1 people chose "The sheet has poor water absorption" 〇: 2-4 people chose "The sheet has poor water absorption" △: 5-7 people chose "The sheet has poor water absorption" ×: Eight or more people chose "The sheet has poor water absorption."

[0122] 2.Easy to wrap around the kitchen towel core The ease of wrapping the kitchen towel around the core during the roll winding process during manufacturing was evaluated through actual processing. The evaluation criteria were as follows: ◎: The kitchen towel was very easy to wrap around the core, and the operability was also very good. ◯: The kitchen towel was easy to wrap around the core, and the operability was also good. △: There was no problem with the ease of winding the kitchen towel onto the core, and there were no problems with operability. ×: It was difficult to wind the kitchen towel around the core, and there were problems with operability.

[0123] 3. Compactness A sensory evaluation of the "compactness" of kitchen towel rolls was conducted by 30 panelists. Each panelist held a kitchen towel roll and asked to choose "compact" or "not compact." The evaluation was based on the number of people who chose "compact." ◎: 28 or more people selected "compact" ○: The number of people who selected "compact" is between 25 and 27 △: The number of people who selected "compact" is between 22 and 24 ×: The number of people who selected "compact" is between 0 and 21

[0124] 4. Core resistance to crushing The "resistance of the core to crushing" of kitchen towel rolls during manufacturing was evaluated by actual processing (cutting with a log saw). The evaluation criteria are as follows: ◎: The percentage of crushed cores was less than 0.5% ○: The percentage of crushed cores was 0.5% or more but less than 1% △: The percentage of crushed cores was 1% or more but less than 2% ×: The percentage of crushed cores was 2% or more.

[0125] [Table 1]

[0126] [Table 2]

[0127] As is clear from the results shown in Tables 1 and 2, the kitchen towel rolls of Examples 1 to 19 were excellent in terms of sheet absorbency, ease of wrapping the kitchen towel around the core, compactness, and resistance to core collapse. In contrast, Comparative Examples 1 to 9 were inferior in any of sheet absorbency, ease of wrapping the kitchen towel around the core, compactness, and resistance to core collapse. In particular, Comparative Example 1, which used a Yankee dryer (YD) for drying in the papermaking process, was excellent in other evaluation items, but exhibited significantly inferior absorbency.

[0128] Therefore, it was confirmed that the kitchen towel roll of the present invention can provide a kitchen towel roll with a sheet that is absorbent, easy to wind the kitchen towel around the core, compact, and a core that is not easily crushed. [Explanation of symbols]

[0129] 1: Kitchen towel roll 1a: surface 1b: Back side 1c: Perforation 1d: Core (paper tube) 1e: The outermost edge of the kitchen towel roll 1x: Kitchen towel 10: Sheet 11: Irregularities caused by the papermaking process 12: Embossed pattern 12a: Linear embossing 13: Radial embossing 14: Closed ring structure embossing 14A: Closed ring structure embossed A 14B: Closed ring structure embossed B 14C: Closed ring structure embossed C 14a: Reference point (of closed ring structure embossed A) 14b: Measurement point (of closed ring structure embossment B) 14c: Measurement point (of closed ring structure embossment C) 14x:Reference line 14y, 14z: Auxiliary line 20: Test piece 20a,20d: Corner 21: Holder 40a: Pulp slurry 40b: Wet paper 40c: dry sheet 41: Head box 42: First fabric (forming fabric) 43: Second fabric (textured fabric) 44: Forming roll 45:Through air dryer 46: Yankee Dryer

Claims

1. A kitchen towel roll in which two to three plies of kitchen towels are laminated and wound around a core in a roll shape, The kitchen towel has a basis weight of 30 g / m ２ 56g / m or more ２ Hereinafter, the water absorption per unit area is 300 g / m ２ More than 600g / m ２ is as follows: When the root mean square height of the surface roughness of the core surface that contacts the kitchen towel is Sq2, Sq2 is 8 μm or less, Roll density is 0.04 g / cm ３ 0.13g / cm or more ３ Below is the A kitchen towel roll.

2. 2. The kitchen towel roll according to claim 1, wherein the core contains 30% by mass or more of LBKP (bleached hardwood kraft pulp).

3. 3. The kitchen towel roll according to claim 1, wherein when the root mean square height of the surface roughness of the surface of the kitchen towel that contacts the core is Sq1, the value represented by the product of Sq1 and Sq2 is 100 or more and 530 or less.

4. 3. The kitchen towel roll according to claim 1, wherein the kitchen towel has irregularities resulting from the papermaking process.

5. 3. The kitchen towel roll according to claim 1, wherein the surface of the kitchen towel that contacts the core does not have an embossed pattern.

6. The kitchen towel roll according to claim 1 or 2, wherein the Sq1 is 38 μm or more and 125 μm or less.

7. 3. The kitchen towel roll according to claim 1, wherein the core is made of a plurality of layers of paper.

8. 3. The kitchen towel roll according to claim 1, wherein the water absorption per unit mass of the kitchen towel is 7 g / g or more and 14 g / g or less.

9. 3. The kitchen towel roll according to claim 1, wherein the roll length is 18 m or more and 45 m or less.

10. 3. The kitchen towel roll according to claim 1, wherein the kitchen towel has a linear embossed pattern.

11. 11. The kitchen towel roll of claim 10, wherein the embossing pattern includes a radial embossing and a closed-ring structure embossing.

12. 12. The kitchen towel roll according to claim 11, wherein the radial embossments and the closed-ring structure embossments are alternately arranged at equal intervals.

13. 13. The kitchen towel roll according to claim 12, wherein the arrangement angle of adjacent identical patterns of the radial embossings and the closed-ring structure embossings is 20° or more and 80° or less with respect to the CD direction of the kitchen towel.

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