Paper towel roll

Abstract

This paper towel roll offers a smooth surface with minimal irregularities that makes it less prone to tearing, a superior feel without roughness or stiffness, excellent water absorption due to its high basis weight, and strong resistance to tearing. [Solution] A paper towel roll is made by winding a paper towel sheet, which is laminated in 2-ply or 3-ply layers, into a roll shape, wherein the basis weight per ply of the paper towel sheet is 40 g / m². 2 More than 80g / m 2 The following specifications apply to product plies with a paper thickness of 0.55 mm to 1.35 mm and a water absorption capacity per unit area of ​​the product ply of 350 g / m². 2 More than 810g / m 2 The following paper towel roll is provided, wherein the root mean square height of the surface roughness on the surface side is 35 μm or more and 155 μm or less.

Description

Technical Field

[0001] The present invention relates to a paper towel roll.

Background Art

[0002] Paper towel sheets and paper towel rolls formed by winding the sheets into a roll are variously developed and sold.

[0003] In recent years, the length of the sheet in one roll of paper towels has been increasing. In addition to the increased length, high-quality products are also required to have qualities such as texture and resistance to tearing.

[0004] Among such high-quality products, paper towel sheets obtained by the so-called TAD (Through Air Drying) papermaking technique (hereinafter also referred to as the "TAD papermaking method") using through-air drying have attracted attention because the sheets are thick, have a soft texture, and are excellent in water absorption.

[0005] Also, in the TAD papermaking technique, since a fabric having irregularities is used, the sheet also has irregularities.

[0006] As a prior art document regarding a manufacturing method for imparting irregularities to such paper products, for example, Patent Document 1 discloses an embossing layer of an embossing belt for embossing a wet fibrous web by pressing in a press part of a tissue paper machine for manufacturing high-bulk tissue paper. The embossing layer is non-woven and has a web conveying side with a surface that cooperates with the fibrous web, and the surface has depressions or raised portions that form a three-dimensional structure on the surface, and the embossing layer is characterized by having a predetermined configuration and conditions.

[0007] Furthermore, as prior art documents relating to paper products manufactured using aerated drying, for example, Patent Document 2 discloses a crepe-free, aerated-dried tissue sheet having a height of about 0.012 millimeters (0.005 inches) or more, having about 10 to about 150 protrusions per 6.45 square centimeters (1 square inch), a machine lateral elongation rate of about 9 percent or more, and a basic weight of about 10 to 70 grams / square meter.

[0008] Furthermore, as prior art documents for manufacturing methods that adjust the size and content of a product while maintaining the quality of the paper product, for example, Patent Document 3 discloses a method for manufacturing a roll-shaped paper product, the manufacturing method comprising the steps of preparing at least one paper web and embossing at least one web using an embossed pattern that covers at least about 22% of the total surface area of ​​the at least one web, wherein the pattern includes at least about 80% linear embossing, and the caliper of the finished product is smaller than the caliper of the embossed base sheet. [Prior art documents] [Patent Documents]

[0009] [Patent Document 1] Patent No. 5504169 [Patent Document 2] Patent No. 3758702 [Patent Document 3] Special Publication No. 2016-540530 [Overview of the project] [Problems that the invention aims to solve]

[0010] Generally, increasing the basis weight of paper products improves water absorption, thickness, and strength. However, high-basis-weight paper towel sheets have the problem that increased strength makes the paper stiff and rough, resulting in an overall inferior tactile feel.

[0011] Furthermore, as mentioned above, TAD papermaking technology uses a fabric with an uneven surface, so the sheet also has an uneven surface. In the manufacturing of the paper towel sheet shown in Figure 7(a), pulp fibers 60 are laminated along the recessed parts 51 and raised parts 52 of the uneven fabric 50 on its surface. At this time, if the basis weight of the sheet is low, that is, if the amount of pulp fibers is small, the papermade sheet will also have an uneven surface, making it rough and inferior to the touch, and the uneven surface of the sheet will make it more prone to holes.

[0012] Therefore, as shown in Figure 7(b), by increasing the basis weight, that is, increasing the amount of pulp fibers during papermaking, the recessed parts 51 are filled with pulp fibers 60, resulting in a smooth surface with a good feel, as well as reduced unevenness in the sheet, making it less prone to holes.

[0013] However, as mentioned above, paper towel sheets manufactured using TAD papermaking technology have excellent water absorption, so we wanted to prevent holes from forming in the sheets by increasing the basis weight. However, while increasing the basis weight improves the surface texture, it also makes the sheet harder and rougher, resulting in an overall inferior texture. Therefore, simply increasing the basis weight did not solve all the problems.

[0014] This invention has been made in view of these circumstances, and aims to provide a paper towel roll that is less prone to tearing due to its smooth surface with minimal irregularities, has a superior feel without roughness or stiffness, has good water absorption due to its high basis weight, and is strong and tear-resistant. [Means for solving the problem]

[0015] The inventors conducted thorough research and discovered that, in a paper towel roll made by laminating a sheet of paper towel material into 2-ply or 3-ply layers and winding it into a roll, by setting the basis weight per product ply, the paper thickness of the product ply, the water absorption per unit area of ​​the product ply, and the root mean square height of the surface roughness on the surface side to within predetermined numerical ranges, it is possible to create a paper towel roll that is less prone to tearing due to its small surface irregularities, has a superior tactile feel without roughness or stiffness, has good water absorption due to its high basis weight, and is strong and tear-resistant, thereby solving the above problems and completing the present invention. In other words, the present invention provides the following.

[0016] (1) A first aspect of the present invention is a paper towel roll in which a paper towel sheet, which is laminated in 2-ply or 3-ply form, is wound into a roll, characterized in that the basis weight per product ply of the paper towel sheet is 40 g / m2 or more and 80 g / m2 or less, the paper thickness of the product ply is 0.55 mm or more and 1.35 mm or less, the water absorption per unit area of ​​the product ply is 350 g / m2 or more and 810 g / m2 or less, and the root mean square height of the surface roughness on the surface side is 35 μm or more and 155 μm or less.

[0017] (2) A second aspect of the present invention is a paper towel roll as described in (1), characterized in that the specific volume of the paper towel sheet is 8.8 cm³ / g or more and 22.0 cm³ / g or less.

[0018] (3) A third aspect of the present invention is a paper towel roll as described in (1) or (2), characterized in that the roll mass of the roll is 170g or more and 700g or less.

[0019] (4) A fourth aspect of the present invention is a paper towel roll according to (1) or (2), characterized in that at least one ply of the paper towel sheet is provided with a linear embossed pattern.

[0020] (5) The fifth aspect of the present invention is the paper towel roll according to (1) or (2), wherein the tensile strength DMDT in the MD direction at the time of drying per product ply of the paper towel sheet is 2100 cN / 75 mm or more and 6500 cN / 75 mm or less.

[0021] (6) The sixth aspect of the present invention is the paper towel roll according to (1) or (2), wherein the tensile strength DCDT in the CD direction at the time of drying per product ply of the paper towel sheet is 2100 cN / 75 mm or more and 6200 cN / 75 mm or less.

[0022] (7) The seventh aspect of the present invention is the paper towel roll according to (1) or (2), wherein the roll length of the roll is 18 m or more and 45 m or less.

[0023] (8) The eighth aspect of the present invention is the paper towel roll according to (1) or (2), wherein the water absorption per unit mass in the product ply of the paper towel sheet is 5.9 g / g or more and 13.0 g / g or less.

[0024] (9) The ninth aspect of the present invention is the paper towel roll according to (1) or (2), wherein the roll density of the roll is 0.055 g / cm3 or more and 0.150 g / cm3 or less.

[0025] (10) The tenth aspect of the present invention is the paper towel roll according to (1) or (2), wherein the winding density of the roll is 0.15 m / cm2 or more and 0.60 m / cm2 or less.

[0026] (11) The eleventh aspect of the present invention is the paper towel roll according to (1) or (2), wherein the roll softness of the roll is 1.2 mm or more and 4.2 mm or less.

[0027] (12) A twelfth aspect of the present invention is a paper towel roll according to (1) or (2), characterized in that the value calculated from (root mean square height of surface roughness on the surface side / basis weight per product ply) in the paper towel sheet is 0.30 or more and 4.50 or less. [Effects of the Invention]

[0028] According to the present invention, it is possible to provide a paper towel roll that is less prone to tearing due to its smooth surface with minimal irregularities, has a superior tactile feel without roughness or stiffness, has good water absorption due to its high basis weight, and is also strong and tear-resistant. [Brief explanation of the drawing]

[0029] [Figure 1] This is a perspective view of a paper towel roll according to one embodiment of the present invention. [Figure 2] This figure shows an example of an embossed pattern applied to a sheet in the paper towel roll of the present invention. [Figure 3] This figure shows the height profile of the surface side of a paper towel sheet on the XY plane, as measured by a microscope, using shades of gray. [Figure 4] This figure shows a method for measuring the water absorption capacity of a paper towel sheet according to the present invention. [Figure 5] This figure shows a part of the papermaking process for the paper towel sheet of the present invention. [Figure 6] A perspective view showing an example of a packaging body including a paper towel roll according to the present invention. [Figure 7] This is an enlarged view showing the surface of the textured fabric during the manufacturing of paper towel sheets with low and high basis weight. [Modes for carrying out the invention]

[0030] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). This embodiment is illustrative for explaining the present invention and is not intended to limit the present invention to the following content. The present invention can be implemented by modifying it as appropriate within the scope of its gist.

[0031] In the context of paper towel sheets, the MD direction refers to the flow direction (Machine Direction) when the paper towel sheet is manufactured, while the CD direction refers to the direction perpendicular to the MD direction (Cross Direction). Furthermore, "product ply" refers to the number of plies in a paper towel sheet. For example, if a paper towel roll is manufactured by winding two sheets of paper towel material together, the product ply will be 2 plies. In addition, the paper towels (rolls, sheets) in this invention include kitchen towels and various types of paper towels (for wiper use).

[0032] <Paper towel roll> Figure 1 is a perspective view of a paper towel roll 1 according to one embodiment of the present invention. As shown in Figure 1, the paper towel roll 1 according to this embodiment is a paper towel roll 1 in which a paper towel sheet 1x, which is made by laminating sheets in 2-ply or 3-ply, is wound into a roll. Preferably, the paper towel sheet 1x has perforations in the roll width direction at approximately equal intervals in the roll winding direction (not shown). As shown in Figure 1, the surface of the paper towel sheet 1x facing outwards from the roll is referred to as surface 1a (the surface of the paper towel sheet 1x), and the surface facing towards the center of the roll is referred to as back surface 1b (the back surface of the paper towel sheet 1x). The edge of the paper towel sheet 1x is referred to as the outermost edge 1e of the paper towel roll 1.

[0033] Paper towel rolls are used, for example, in home kitchens and restaurant kitchens for wiping up moisture or oil and removing dirt. Types of paper towel rolls include kitchen paper rolls (sometimes called paper towels or cooking paper), hand towels, wipers, and other sanitary paper rolls.

[0034] (Roll length and roll diameter) The length of the paper towel roll 1 is preferably between 18m and 45m. If the length is less than 18m, and the roll diameter DR remains unchanged, the roll density will be low and the roll will be prone to crushing, resulting in a paper towel sheet 1x with an inferior feel. If the length exceeds 45m, the roll density will be high and the roll will become tightly wound, resulting in a paper towel sheet 1x with an inferior feel. Furthermore, the length of the paper towel roll 1 is more preferably 22m or more at the lower limit, and even more preferably 25m or more. The upper limit is more preferably 40m or less, and even more preferably 31m or less.

[0035] The roll length is measured as follows: First, measure the length of 10 sheets of paper towels between the perforations of paper towel roll 1. Then, measure the number of sheets in paper towel 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 the number of sheets is 150, then 1.80m × (150 / 10) = 27m. If paper towel roll 1 does not have perforations, measure the roll length directly.

[0036] The winding diameter DR of the paper towel roll 1 according to this embodiment is preferably 130 mm or more at the lower limit, more preferably 135 mm or more, and even more preferably 145 mm or more. The upper limit is preferably 185 mm or less, more preferably 163 mm or less, and even more preferably 155 mm or less. If the roll diameter DR is less than 130mm, the roll will be tightly wound if the length remains the same, resulting in a paper towel sheet with an inferior feel. If the roll diameter DR exceeds 185mm, the paper towel roll becomes more prone to crushing, resulting in a paper towel sheet with an inferior feel.

[0037] The roll diameter DR is measured using a Diameter Rule manufactured by Muratec KDS Co., Ltd. Three paper towel rolls are measured, and the results are averaged.

[0038] (Roll width and roll mass) The roll width (sheet width) of paper towel roll 1 is preferably 200 mm or more at the lower limit, more preferably 220 mm or more, and even more preferably 260 mm or more. The upper limit is preferably 320 mm or less, more preferably 310 mm or less, and even more preferably 290 mm or less. If the roll width is less than 200mm, the sheet area is small, resulting in poor water absorption. If the sheet width exceeds 320mm, the sheet area per sheet increases, leading to increased usage and making it more difficult to use.

[0039] Furthermore, the roll weight of the paper towel roll 1 is preferably between 170g and 700g. If the roll weight is less than 170g, the basis weight is low, resulting in poor water absorption of the paper towel sheet 1x. If the roll weight exceeds 700g, the basis weight is high, resulting in poor tactile feel of the paper towel sheet 1x. Furthermore, the roll mass of paper towel roll 1 is more preferably 330g or more at the lower limit, and even more preferably 430g or more. The upper limit is more preferably 600g or less, and even more preferably 550g or less.

[0040] The roll mass is defined as the mass per 280 mm of roll width, excluding the paper tube 2 (core) in paper towel roll 1. If the sheet width is not 280 mm, the mass per 280 mm will be converted using proportional calculation.

[0041] (Roll density) In this embodiment, the roll density of the paper towel roll 1 is preferably 0.055 g / cm³ or more and 0.150 g / cm³ or less. If the roll density is less than 0.055 g / cm³, the roll is easily crushed, and the paper towel sheets 1x have an inferior feel. If the roll density exceeds 0.150 g / cm³, the paper towel roll 1 becomes tightly wound, and as a result, the paper towel sheets 1x have an inferior feel. In this embodiment, the roll density of the paper towel roll 1 is more preferably 0.075 g / cm³ or higher at the lower limit, and even more preferably 0.090 g / cm³ or higher. Furthermore, the upper limit is more preferably 0.130 g / cm³ or lower, and even more preferably 0.120 g / cm³ or lower.

[0042] Roll density is expressed as (roll mass) ÷ (roll volume). Roll mass is the mass of one paper towel roll per 280 mm roll width. Roll volume is expressed as [{cross-sectional area of ​​the outer diameter (winding diameter DR) portion of the roll} - (cross-sectional area of ​​the outer diameter DI portion of the paper core)] × roll width (converted to per 280 mm). For example, if the roll mass (excluding paper core 2) per 280 mm roll width is 426 g, the winding diameter DR is 146 mm, and the outer diameter DI of the paper core is 46 mm, then the roll density = 426 g ÷ [{3.14 × (146 mm ÷ 2 ÷ 10)² - 3.14 × (46 mm ÷ 2 ÷ 10)²} × (280 mm ÷ 10)] = 0.101 g / cm³.

[0043] (winding density) The winding density of the paper towel roll 1 according to this embodiment is preferably 0.15 m / cm² or more and 0.60 m / cm² or less. If the winding density is less than 0.15 m / cm², the roll becomes easily crushed, and the paper towel sheets 1x have an inferior feel. If the winding density exceeds 0.60 m / cm², the roll becomes tightly wound, and the paper towel sheets 1x have an inferior feel. In this embodiment, the winding density of the paper towel roll 1 is more preferably 0.18 m / cm² or higher at the lower limit, and even more preferably 0.20 m / cm² or higher. Furthermore, the upper limit is more preferably 0.51 m / cm² or lower, and even more preferably 0.43 m / cm² or lower.

[0044] The winding density is expressed as (winding length × number of plies) ÷ (cross-sectional area of ​​the roll). The cross-sectional area of ​​the roll is expressed as {cross-sectional area of ​​the outer diameter (winding diameter DR) portion of the roll - (cross-sectional area of ​​the outer diameter DI portion of the paper core)}. For example, in the case of a winding length of 27m, 2 plies, winding diameter DR of 150mm, and paper core outer diameter DI of 39mm, the winding density = (27m × 2) ÷ {3.14 × (150mm ÷ 2 ÷ 10)² - 3.14 × (39mm ÷ 2 ÷ 10)²} = 0.33 m / cm².

[0045] (Softness of winding) In this embodiment, the winding flexibility of the paper towel roll 1 is preferably 1.2 mm or more and 4.2 mm or less. If the winding flexibility is less than 1.2 mm, the paper towel roll 1 becomes tightly wound, and as a result the paper towel sheets 1x have a poor tactile feel. If the winding flexibility exceeds 4.2 mm, the paper towel roll 1 becomes easily crushed, and as a result the paper towel sheets 1x have poor water absorption. In this embodiment, the softness of the paper towel roll 1 is more preferably 1.5 mm or more at the lower limit, and even more preferably 1.8 mm or more. The upper limit is more preferably 3.5 mm or less, and even more preferably 3.0 mm or less.

[0046] The softness of the paper towel roll 1 is measured using a compression tester (KES-G5 handy compression tester manufactured by Kato Tech Co., Ltd.) as follows. The direction parallel to the axis of the paper towel roll 1 is defined as the height direction, and the direction perpendicular to the tangent to the circumference of the paper towel roll 1 is defined as the radius direction. First, place the paper towel roll 1 horizontally on a hard surface so that its axis is horizontal. Then, press the KES-G5 compressor (area 2.0 cm²) radially from above into the center of the paper towel roll 1 in the height direction at a speed of 10 mm / min. Let T0 be the indentation depth when the pressure applied by the compressor to the roll is 5 gf / cm², and Tm be the indentation depth when the pressure is 150 gf / cm². Calculate (Tm-T0). Next, rotate the paper towel roll 1 90 degrees circumferentially around its axis, and measure the indentation depths Tm and T0 as described above. Calculate the difference between Tm and T0 (Tm-T0). The measurement is performed twice for each paper towel roll 1 as described above. That is, for three paper towel rolls 1, each is measured twice, and the average of the total six measurements (= 2 times / roll × 3 rolls) is used as the final roll softness.

[0047] (Paper tube outer diameter) Furthermore, the outer diameter DI of the paper tube 2, which is the outer diameter of the core of the paper towel roll 1 of the present invention, is preferably 20 mm or more at the lower limit, more preferably 30 mm or more, and even more preferably 38 mm or more. The upper limit is preferably 60 mm or less, more preferably 55 mm or less, and even more preferably 50 mm or less. If the paper core outer diameter DI is less than 20 mm, and the winding diameter DR remains unchanged, the roll density will be low, making the roll more prone to crushing, resulting in a paper towel sheet with an inferior feel. If the paper core outer diameter DI exceeds 60 mm, and the winding diameter remains unchanged, the roll density will be high, resulting in a tightly wound roll, and a paper towel sheet with an inferior feel.

[0048] The outer diameter DI of the paper core is measured using a Diameter rule manufactured by Muratec KDS Co., Ltd. Measurement is performed by measuring three paper towel rolls 1 and averaging the results. If there is no paper core 2 in the core, the diameter of the cavity in the core portion is measured and used as the outer diameter DI of the paper core.

[0049] The paper tube 2 is made by stacking multiple sheets of base paper, and it is preferable that it is made of two sheets. Bleached kraft pulp (BKP) is preferred as the pulp fiber contained in the base paper. The BKP content in the base paper is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. If the BKP content is less than 50% by mass, the core (paper tube 2) will be easily crushed. In this case, it is preferable that the BKP contained includes bleached hardwood kraft pulp (LBKP). The LBKP content is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. If the LBKP content is less than 50% by mass, the manufacturing cost of the paper towel roll 1 will increase as a result.

[0050] <Paper towel sheets> The paper towel sheet 1x according to this embodiment preferably contains wet pulp. Furthermore, it is preferable that the wet pulp content is 50% by mass or more. If the wet pulp content is less than 50% by mass, the water absorption capacity of the paper towel sheet 1x will be low. Furthermore, the wet pulp content in the paper towel sheet 1x is more preferably 70% by mass or more, and even more preferably 90% by mass or more. In this case, the wet pulp content of the paper towel sheet 1x refers to the content in the product ply. In this embodiment, wet pulp refers to the wet pulp (sheet) or slush pulp described above, and is pulp with a solid content of 60% by mass or less, preferably 1% to 50% by mass, more preferably 2% to 20% by mass, and even more preferably 3% to 10% by mass. The solid content of dry pulp (sheet) is approximately 90% by mass.

[0051] Furthermore, the pulp includes bleached softwood kraft pulp (NBKP) and bleached hardwood kraft pulp (LBKP). The preferred mass ratio of bleached softwood kraft pulp (NBKP) to bleached hardwood kraft pulp (LBKP) in a paper towel sheet 1x is NBKP:LBKP = 40-100% by mass:0-60% by mass. If the mass ratio of NBKP is too low, the paper towel sheet 1x will tear easily. If the mass ratio of LBKP is too high, the paper towel sheet 1x will tear easily. If the mass ratio of NBKP is too high, the cost of the paper towel sheet 1x will increase. If the mass ratio of LBKP is too low, the cost of the paper towel sheet 1x will increase. In a paper towel sheet 1x, the mass ratio of bleached softwood kraft pulp (NBKP) to bleached hardwood kraft pulp (LBKP) is more preferably NBKP:LBKP = 50-90% by mass:10-50% by mass, and even more preferably NBKP:LBKP = 60-80% by mass:20-40% by mass.

[0052] Furthermore, for pulp processing, NBKP is preferably beaten, while LBKP is preferably not beaten. In addition, other pulps (such as recycled pulp) may be included in a ratio of preferably 20% by mass, more preferably 10% by mass, even more preferably 5% by mass, and most preferably 0% by mass, relative to the ratio of NBKP to LBKP.

[0053] (Basic weight) The basis weight per ply of the paper towel sheet 1x according to this embodiment is 40 g / m2 or more and 80 g / m2 or less. If the basis weight per ply is less than 40 g / m2, the surface of the paper towel sheet 1x will become uneven, making it prone to holes and also resulting in poor water absorption. If the basis weight per ply exceeds 80 g / m2, the paper towel sheet 1x will have an inferior feel. The basis weight per ply of a paper towel sheet 1x is preferably 45 g / m2 or more at the lower limit, and more preferably 50 g / m2 or more. The upper limit is preferably 75 g / m2 or less, and more preferably 70 g / m2 or less. The basis weight per ply of a paper towel sheet 1x can be measured according to JIS P 8124.

[0054] (paper thickness) The paper thickness of the product ply of a 1x paper towel sheet is between 0.55 mm and 1.35 mm. If the paper thickness of the product ply is less than 0.55 mm, the 1x paper towel sheet will have poor water absorption. If the paper thickness of the product ply exceeds 1.35 mm, the 1x paper towel sheet will have poor tactile properties. Furthermore, the paper thickness of the product ply of the paper towel sheet 1x is preferably 0.62 mm or more at the lower limit, and more preferably 0.75 mm or more. The upper limit is preferably 1.15 mm or less, and more preferably 1.00 mm or less.

[0055] The paper thickness of a 1x paper towel sheet can be measured using a thickness gauge (the "PEACOCK" dial thickness gauge manufactured by Ozaki Seisakusho Co., Ltd.). The measurement conditions are a measuring load of 3.7 kPa and a probe diameter of 30 mm. The sample is placed between the probe and the measuring stand, and the gauge is read when the probe is lowered at a speed of 1 mm or less per second. The sample used for measurement is a 1x paper towel sheet in its original product ply. The measurement is repeated 10 times at different locations, and the average of the measurement results is used as the final paper thickness.

[0056] (Sheet length) The sheet length between perforations (length of one paper towel sheet in the roll winding direction) is preferably 100 mm or more at the lower limit, more preferably 130 mm or more, and even more preferably 150 mm or more. The upper limit 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 100mm, the sheet area of ​​one paper towel sheet is small, resulting in poor absorbency. If the sheet length exceeds 250mm, the sheet area per paper towel sheet is large, increasing the amount used and making it more difficult to use.

[0057] (specific volume) The specific volume of a paper towel sheet 1x is preferably between 8.8 cm³ / g and 22.0 cm³ / g. If the specific volume is less than 8.8 cm³ / g, the paper towel sheet 1x will have poor water absorption. If the specific volume exceeds 22.0 cm³ / g, the paper towel sheet 1x will become easily crushed and more prone to developing holes during water absorption. Furthermore, the specific volume of a paper towel sheet 1x is more preferably 9.5 cm³ / g or more at the lower limit, and even more preferably 10.9 cm³ / g or more. The upper limit is more preferably 18.5 cm³ / g or less, and even more preferably 17.8 cm³ / g or less. The specific volume of a paper towel sheet 1x is calculated by dividing the paper thickness per ply by the basis weight per ply (paper thickness per product ply = basis weight per product ply) in the paper towel sheet 1x of the product ply, and expressing it as volume per unit (g) (cm³).

[0058] (DMDT and DCDT) The Dry Machine Direction Tensile Strength (DMDT) per ply of a paper towel sheet 1x is preferably between 2100 cN / 75 mm and 6500 cN / 75 mm. If the DMDT is less than 2100 cN / 75 mm, the paper towel sheet 1x will tear easily. Conversely, if the DMDT exceeds 6500 cN / 75 mm, the paper towel sheet 1x will have an inferior tactile feel. Furthermore, the DMDT per product ply of a paper towel sheet 1x is more preferably 2800 cN / 75 mm or more at the lower limit, and even more preferably 3600 cN / 75 mm or more. The upper limit is more preferably 5800 cN / 75 mm or less, and even more preferably 4800 cN / 75 mm or less.

[0059] Furthermore, the Dry Cross Direction Tensile Strength (DCDT) per ply of the paper towel sheet 1x in the CD direction when dry is preferably 2100 cN / 75 mm or more and 6200 cN / 75 mm or less. If the DCDT is less than 2100 cN / 75 mm, the paper towel sheet 1x will tear easily. Also, if the DCDT exceeds 6200 cN / 75 mm, the paper towel sheet 1x will have an inferior feel. Furthermore, the DCDT per product ply of a 1x paper towel sheet is more preferably 2800 cN / 75 mm or more at the lower limit, and even more preferably 3600 cN / 75 mm or more. The upper limit is more preferably 5500 cN / 75 mm or less, and even more preferably 4800 cN / 75 mm or less.

[0060] The DMDT and DCDT per ply of a paper towel sheet (1x) shall be measured in accordance with JIS P 8113. Note that the paper towel sheet (1x) shall be measured in its original product ply form for DMDT and DCDT measurement.

[0061] (Embossed) The paper towel roll 1 (paper towel sheet 1x) of this embodiment is embossed, and preferably has a linear embossed pattern 10. Furthermore, it is preferable that the paper towel sheet 1x in this invention is embossed on at least one ply and then laminated to form two or three plies. Note that if the paper towel sheet 1x exceeds three plies within a certain range of product ply basis weight, the basis weight per ply in the paper towel sheet 1x decreases, resulting in a tendency for holes to form. When laminating in 2-ply or 3-ply layers, it is preferable to use, for example, plybond glue (adhesive) and apply the glue for bonding. By bonding in this way to create 2-ply or 3-ply layers, the adhesion between the plies becomes stronger, and the paper towel sheet 1x becomes less likely to tear even when wet, without the plies peeling off. Alternatively, water may be used instead of plybond glue (adhesive), or the glue and water may be mixed. If the embossed pattern 10 on the paper towel sheet 1x is dots rather than lines, the embossing becomes more easily crushed, resulting in the paper towel sheet 1x having poor water absorption.

[0062] It is preferable that at least the surface 1a side of the paper towel sheet 1x has a linear embossed pattern 10. By applying the embossed pattern 10 to the surface 1a side, glue can be applied to the embossed protrusions and laminated into two plies. The back side 1b side of the sheet may have the embossed pattern 10, but it is preferable that it does not have it. By not having the embossed pattern 10 on the back side 1b side, a paper towel sheet 1x (paper towel roll 1) with a superior texture can be made.

[0063] Figure 2 shows an example of an embossed pattern 10 applied to a paper towel sheet 1x in the paper towel roll 1 of this embodiment. The embossed pattern 10 preferably includes radial embossing 11 and closed-ring structure embossing 12. If radial embossing 11 is not included, the aesthetic appeal of the paper towel sheet 1x as a product will be inferior. If closed-ring structure embossing 12 is not included, the paper towel sheet 1x will have inferior water absorption. Furthermore, it is preferable that the radial embossing 11 and the closed-ring structure embossing 12 are arranged alternately at equal intervals. By arranging them alternately at equal intervals, a paper towel sheet 1x with excellent water absorption and ease of use as a product can be obtained.

[0064] The overall shape of the radial emboss 11 is not particularly limited, but it is preferable to have multiple straight line embossings extending outward from the center, or multiple embossings of shapes made up of straight lines. The inclusion of radial embossing 11 in the embossing pattern 10 results in a product with good aesthetic appeal for the paper towel sheet 1x. The closed-ring structure embossing 12, like the radial embossing 11, is not particularly limited in its overall shape, but it is preferable that it includes a linear or geometric embossing in the center surrounded by a geometric embossing on the outside to form a closed-ring structure. By including the closed-ring structure embossing 12 in the embossing pattern 10, water is retained inside the embossing, resulting in good water absorption in the paper towel sheet 1x.

[0065] In this case, the embossing depth in the embossing pattern 10 is preferably 0.06 mm or more at the lower limit, more preferably 0.10 mm or more, and even more preferably 0.15 mm or more. The upper limit 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 paper thickness will be reduced, and the water absorption may be poor. If the embossing depth exceeds 1.05 mm, the paper towel sheet 1x will be more prone to holes. The measurement and calculation methods are described in detail, for example, in Japanese Patent Publication No. 2022-066267. In addition to the methods described above, the depth of the embossing can also be determined using a microscope in the following way (not shown in the diagram).

[0066] The microscope used is the VR-6100 one-shot 3D shape measuring machine (head) manufactured by Keyence Corporation. The observation and measurement software for the microscope images is the VR-6000 observation application, also manufactured by Keyence Corporation, and the image analysis software is the VR-6000 analysis application, also manufactured by Keyence Corporation. The measurement conditions are 12x magnification and a field of view of 24mm x 18mm. The measurement magnification and field of view may be changed as appropriate depending on the desired size of the embossing. First, measure the embossing to be measured on the surface side of a paper towel sheet 1x using the "VR-6000 observation application". When measuring, remove three turns of paper towel sheet 1x from the paper towel roll 1, and use the fourth turn of paper towel sheet 1x to measure the product ply sheet (hereinafter also referred to as the "measurement sample"). If curl (undulation) is observed in the measurement sample, it is preferable to place weights on both ends of the measurement sample (parts not to be observed) to flatten the curl (undulation) of the measurement sample before measuring.

[0067] Next, the "VR-6000 Analysis Application" is used to remove tilt, curl (undulation), etc., from the measured image of the sample. In the "VR-6000 Analysis Application," select "Image Processing" and perform "Surface Shape Correction." Select "Waviness Removal" as the correction method. Here, the degree of correction can be adjusted by setting the "Correction Strength" and "Numerical Specification," but setting the "Correction Strength" to 5 is preferable as it will almost completely remove the tilt and curl (undulation) of the sample sheet. Note that the "Correction Strength" may be changed as appropriate depending on the desired embossing and the condition of the sample. After completing the "surface shape correction," select the "surface roughness measurement" function and define the area where you want to measure the emboss depth in the editing screen. The area should include both the recessed and unembossed parts of the surface. Use the rectangular numerical specification to set a 10mm x 10mm square area (if the emboss is linear, it may extend beyond the 10mm x 10mm area). If the emboss is larger than a 10mm square, you may change the numerical specification or area setting tool to match emboss pattern 10.

[0068] Next, under "Roughness Parameters," select "Sz Maximum Height" (Sz = Sp Maximum Peak Height + Sv Maximum Valley Depth). Once the area and parameters are set, perform the measurement and check the measured value. Here, "Sz maximum height" is defined as the embossing depth. Using this method, "Sz maximum height" can be obtained automatically. Note that if the ply embossing is convex rather than concave, the measurement can be performed using "Sz maximum height = Sp maximum peak height + Sv maximum valley depth". Similarly, the measurement position of the sample is shifted and the measurement is taken a total of five times (five different embossed areas), and the average value of the "Sz maximum height" is finally adopted as the embossing depth.

[0069] Furthermore, the embossed pattern 10 preferably includes linear embossed portions 100, and the proportion of linear embossed portions 100 included in the embossed pattern 10 is preferably 20% or more. If the proportion is less than 20%, the embossed pattern 10 cannot contribute to improving the feel and absorbency, and the paper towel sheet 1x will have inferior feel and absorbency. Furthermore, the proportion of linear embossed portions 100 included in the embossed pattern 10 is more preferably 50% or more, and even more preferably 90% or more.

[0070] In this case, the linear embossed portion 100 refers to an embossed area that is 0.1 mm or more in thickness and 4.0 mm or less in length and 5 mm or more in length. The percentage of the linear embossed portion (100%) is determined as follows: First, divide any 100mm x 100mm area on the embossed surface of the paper towel sheet 1x into 10mm squares. Then, calculate the proportion of the linear embossed area 100 using the following formula. If a single square contains both linear and dot embossing, use the square with the larger proportion of embossing. (Number of squares containing linear embossing / Number of squares containing any type of embossing) × 100 = Percentage of linear embossing (%)

[0071] Furthermore, the back surface 1b of the paper towel sheet 1x has a pattern of irregularities derived from a papermaking process different from the embossing pattern 10 described later, and there are no particular restrictions on whether or not the embossing pattern 10 is applied. Nested embossing or pin-to-pin embossing may be applied, or there may be no embossing at all, but nested embossing or no embossing is preferred, and more preferably no embossing.

[0072] Furthermore, the root mean square height Sq of the surface roughness on the surface 1a side of the paper towel sheet 1x is between 35 μm and 155 μm. If the root mean square height Sq of the surface roughness is less than 35 μm, the specific surface area on the surface 1a side of the paper towel sheet 1x becomes small, resulting in lower water absorption of the paper towel sheet 1x. If the root mean square height Sq of the surface roughness exceeds 155 μm, irregularities will form on the surface 1a side of the paper towel sheet 1x, making it more prone to holes. Furthermore, the root mean square height Sq of the surface roughness on the surface 1a side of the paper towel sheet 1x is preferably 50 μm or more at the lower limit, and more preferably 60 μm or more. The upper limit is preferably 125 μm or less, and more preferably 100 μm or less.

[0073] Furthermore, it is preferable that the value calculated from (the root mean square height of the surface roughness on the surface 1a side Sq / basis weight per product ply) of the paper towel sheet 1x be between 0.30 and 4.50. If the value is less than 0.30, the paper towel sheet 1x will have an inferior tactile feel. If the value exceeds 4.50, the paper towel sheet 1x will have an inferior tactile feel. Furthermore, for the paper towel sheet 1x, the value calculated from (root mean square height of surface roughness on surface 1a side Sq / basis weight per product ply) is more preferably 0.50 or higher at the lower limit, and even more preferably 0.80 or higher. The upper limit is more preferably 3.00 or lower, and even more preferably 2.60 or lower.

[0074] The root mean square height Sq of the surface roughness on surface 1a is measured using a microscope. The microscope used is the KEYENCE VR-6100, a one-shot 3D shape measuring machine (head). The VR-6000 observation application and VR-6000 analysis application are used for image observation and measurement. Measurement conditions are 12x magnification and a field of view of 24mm x 18mm. The magnification and field of view may be adjusted as needed depending on the desired emboss size.

[0075] Figure 3 shows the height profile on the XY plane on the surface 1a side, as measured by a microscope, using shades of gray. The image obtained, shown in Figure 3, is then filtered. Specifically, an S-filter (low-pass filter) is used to remove components on a scale smaller than the cutoff wavelength, and an L-filter (high-pass filter) is used to remove components on a scale larger than the cutoff wavelength. Here, the S-filter is set to 500 μm and the L-filter to 8 mm. Once the S-filter and L-filter are selected, the root mean square height (Sq) is automatically calculated.

[0076] On the surface 1a side, remove three turns of paper towel sheet 1x from paper towel roll 1, and measure using the fourth turn of paper towel sheet 1x without changing the number of plies. If there are perforations, measure while avoiding them. Measure at two locations in the roll width direction (CD direction) of paper towel roll 1, and then rotate paper towel roll 1 in the roll winding direction three times by 90 degrees each time, performing the same measurement at each position (a total of four measurement locations in the roll winding direction). The average value of these eight locations (2 x 4) is finally adopted as the root mean square height Sq. Note that if there are irregularities in the embossed pattern 10, it may be difficult to measure accurately. Therefore, measurements should generally be taken on the surface 1a side of the paper towel sheet 1x, avoiding the embossed pattern 10. However, if it is not possible to avoid the embossed pattern 10 on the surface 1a side, measurements should be taken on the back side 1b side, avoiding the embossed pattern 10. If it is also not possible to avoid the embossed pattern 10 on the back side 1b side, measurements may be taken in the area including the embossed pattern 10, while avoiding the embossed pattern 10 as much as possible. Furthermore, in areas of the surface 1a side of the paper towel sheet 1x where the embossed pattern 10 is not applied, measurements should be taken in areas where the ply is not adhered by plybond glue. However, if measurement is not possible without including areas where the ply is adhered, these areas may be included.

[0077] (Water absorption) In this embodiment, the water absorption per unit area of ​​the product ply of the paper towel sheet 1x is 350 g / m2 or more and 810 g / m2 or less. If the water absorption per unit area is less than 350 g / m2, the paper towel sheet 1x has poor water absorption. If the water absorption per unit area exceeds 810 g / m2, the basis weight of the paper towel sheet 1x becomes high, the paper becomes hard and rough, and the overall tactile feel is inferior. Furthermore, the water absorption per unit area of ​​the product ply of the paper towel sheet 1x is preferably 400 g / m2 or more at the lower limit, and more preferably 500 g / m2 or more. The upper limit is preferably 750 g / m2 or less, and more preferably 660 g / m2 or less.

[0078] Furthermore, it is preferable that the water absorption per unit mass of the product ply of the paper towel sheet 1x is between 5.9 g / g and 13.0 g / g. If the water absorption per unit mass is less than 5.9 g / g, the paper towel sheet 1x will have poor water absorption. If the water absorption per unit mass exceeds 13.0 g / g, the paper towel sheet 1x will tear easily. Furthermore, for each product ply of paper towel sheets 1x, the water absorption per unit mass is more preferably 6.8 g / g or more at the lower limit, and even more preferably 7.5 g / g or more. The upper limit is more preferably 12.0 g / g or less, and even more preferably 11.3 g / g or less.

[0079] The method for measuring the water absorption capacity of each paper towel sheet 1x is explained below, with reference to Figure 4. First, a paper towel sheet 1x stacked on the product ply is taken and cut using a 7.6cm square template to create a rectangular test piece 20 with sides of 7.6cm. The mass of the test piece 20 before water absorption is measured using an electronic balance. The test piece 20 is then placed in a holder 21 (a jig that secures the test piece 20 at three points; the jig is made of a metal that does not absorb moisture).

[0080] Next, fill a commercially available tray with distilled water to a depth of 2 cm, and immerse the test piece 20, which is set in the holder 21, in the distilled water for 2 minutes. After 2 minutes of immersion, remove the test piece 20 and the holder 21 from the distilled water, and hang the holder 21 and the test piece 20 from a rod placed in an empty water tank with the corner 20a facing upwards. Close the lid of the water tank and leave it for 5 minutes.

[0081] Next, the holder 21 and test piece 20 are removed from the water bath, the holder 21 is removed, and the mass of the test piece 20 is measured using an electronic balance. From the change in mass of the test piece 20 before and after immersion in distilled water, the amount of distilled water absorbed per unit area of ​​the test piece 20 (water g / sheet m2, per 1 m2; abbreviated as g / m2) is calculated. Furthermore, by dividing the amount of water absorbed per unit area (water g / sheet m2) by the basis weight of the product ply of the test piece 20, the amount of water absorbed per unit area (water g / sheet m2) / basis weight (sheet g / sheet m2) = amount of water absorbed per unit mass (water g / sheet g, per 1 g; abbreviated as g / g) is calculated. Measurements are performed 5 times for each sample, and the average value is adopted.

[0082] <How to manufacture paper towel rolls> A paper towel roll 1 can be manufactured, for example, in the following order: (1) papermaking and creping, (2) embossing and bonding, and (3) roll winding. In the paper towel sheet 1x manufacturing (papermaking) process, it is preferable to use the TAD papermaking method.

[0083] In this case, during the papermaking process, it is preferable that a different uneven pattern 13, derived from the papermaking process (fabric), is applied to the paper towel sheet 1x, as shown in Figure 2. If this uneven pattern 13 is not present, the paper towel sheet 1x will have poor water absorption.

[0084] "Originating from the papermaking process" means that in the papermaking process of the paper towel sheet 1x, a pattern of bumps and dips is applied between the headbox 41 of the papermaking machine and the outlet of the Yankee dryer 46. Specifically, in a part of the papermaking process shown in Figure 5, paper web 40a, which is in the state of pulp slurry, is sprayed (supplied) from the headbox 41 between the first fabric (forming fabric) 42 and the second fabric (bumpy fabric) 43, and is drawn onto the second fabric (bumpy fabric) 43 by the forming roll 44, forming paper web 40b, which is in the state of wet paper. Next, the paper web 40b is dried together with the second fabric (textured fabric) 43 in the through-air dryer 45, resulting in the formation of texture on the dried sheet of paper web 40c. In Figure 5, two through-air dryers 45 are shown, but one unit may suffice. Also, a Yankee hood is shown on the Yankee dryer 46, but the hood is not required. Furthermore, a crepe texture may be applied in the Yankee dryer 46.

[0085] Furthermore, the uneven surface pattern 13 can be changed as appropriate by changing the fabric pattern (fine pattern, coarse pattern). Changing the uneven surface pattern 13 changes the root mean square height Sq of the surface roughness, but it is preferable to select a pattern such that the root mean square height Sq of the surface roughness falls within the numerical range described above. Furthermore, in the papermaking process shown in Figure 7(b), the lower side of the sheet (fabric 50 side) is rough due to its contact with the fabric 50, resulting in a more uneven surface. Conversely, the upper side of the sheet (pulp fiber 60 side) is smoother than the lower side because it has a higher basis weight in the paper towel sheet 1x of the present invention. By making this side the Yankee side, the smoothness is improved. Also, when forming the product (paper towel roll 1 wound with 2-ply or 3-ply paper towel sheets 1x), it is preferable to make the Yankee side on the pulp fiber 60 side the outer surface of the product, as this reduces the roughness when the product is held.

[0086] (packaging) Furthermore, the paper towel rolls 1 according to this embodiment may be individually packaged after manufacturing, or they may be packaged in a so-called multi-pack, where several individually packaged rolls are further packaged together. In this case, the number of packages in the multipack is not particularly limited, but it is preferable to package two or three rolls of paper towel 1, and more preferably three rolls. As an example of the packaging form, as shown in Figure 6, individually packaged paper towel rolls 1 (not shown) can be arranged so that the axial directions of three rolls are approximately parallel, and then wrapped with film 3 to form a paper towel roll package 200.

[0087] As described above, according to this embodiment, it is possible to provide a paper towel roll that is less prone to holes due to its smooth surface, has a superior tactile feel without roughness or stiffness, has good water absorption due to its high basis weight, and is also strong and tear-resistant.

[0088] 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 obvious to those skilled in the art that various modifications or improvements can be made to the above embodiments. Furthermore, it is clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention. [Examples]

[0089] The present invention will be described in detail below with reference to examples. However, the present invention is not limited in any way to the examples shown below.

[0090] Paper towel rolls (kitchen towel rolls) for Examples 1 to 12 and Comparative Examples 1 to 4 shown in Table 1 were manufactured through the following processes: (1) TAD papermaking and creping, (2) embossing and lamination, and (3) roll winding. The above parameters were measured for all paper towel rolls of the examples and comparative examples, and the following evaluations were performed. For each of the evaluations below, a score of 1 was considered a failure, and a score of 2 or higher was considered a pass. In addition, all parameters other than those evaluated below were measured according to the criteria or measurement methods described above.

[0091] 1. Resistance to tearing of the sheet A sensory evaluation of the tear resistance of paper towels after manufacturing was conducted using 30 monitors. Three turns of paper towels were removed from the paper towel roll, and one sheet (sheet width (CD direction) 280 mm, sheet length (MD direction) 180 mm) was cut from the fourth turn. The sheet was then passed back and forth 10 times on a dry surface, and the monitors were asked to choose between "the sheet did not tear" or "the sheet tore." The number of people who chose "the sheet tore" was used to evaluate the sheet on a 4-point scale. The evaluation criteria are as follows: 4 points: 0-1 person selected "The sheet is torn." 3 points: 2 to 4 people selected "The sheet is torn." 2 points: 5-7 people selected "The sheet is torn." 1 point: 8 or more people selected "The sheet is torn".

[0092] 2. The feel of the sheet A sensory evaluation of the "texture" of manufactured paper towels was conducted by 30 monitors. Three turns of paper towels were removed from the paper towel roll, and one sheet (sheet length (MD direction) 180 mm) was cut from the fourth turn. The monitors were asked to choose between "the sheet is rough and stiff, with a poor texture" and "the sheet is smooth and soft, with a good texture." The evaluation was given on a four-point scale based on the number of people who selected "the sheet is rough and stiff, with a poor texture." The evaluation criteria are as follows. 4 points: 0-1 person selected "The sheet is rough and stiff, and has a bad texture." 3 points: 2-4 people selected the option "The sheet is rough and stiff, and has a bad texture." 2 points: 5-7 people selected the option "The sheet is rough and stiff, and has a bad texture." 1 point: 8 or more people selected "The sheet is rough and stiff, and has a bad texture."

[0093] 3. Resistance to holes in the sheet The number of holes on the surface of the paper towels after manufacturing was visually inspected and evaluated by 30 monitors. They selected either "many holes on the surface and back of the sheet" or "few holes on the surface and back of the sheet," and the evaluation was rated on a four-point scale based on the number of people who felt that "many holes on the surface and back of the sheet." The evaluation criteria are as follows: 4 points: 0-1 person or less felt that there were "too many holes on the surface or back of the sheet". 3. 2-4 people felt that there were many holes on the front or back of the sheet. 2. 5-7 people felt that there were many holes on the front or back of the sheet. 1 point: More than 8 people felt that there were many holes on the surface or back of the sheet.

[0094] 4. Water absorption of the sheet The "water absorption" of manufactured paper towels was evaluated by 30 monitors through sensory evaluation. Three turns of paper towels were removed from the paper towel roll, and one sheet (sheet width (CD direction) 280 mm, sheet length (MD direction) 180 mm) was cut from the fourth turn of paper towels. 40 g of water was then wiped up using the sheet. Monitors evaluated the paper towels in the way they normally use them, selecting either "the sheet has excellent water absorption" or "the sheet has poor water absorption." The evaluation was then categorized into four levels based on the number of people who selected "the sheet has poor water absorption." The evaluation criteria are as follows: 4 points: 0-1 person selected "The sheet has poor water absorption." 3 points: 2-4 people selected "The sheet has poor water absorption." 2. 5-7 people selected "The sheet has poor water absorption." 1 point: 8 or more people selected "The sheet has poor water absorption."

[0095] [Table 1]

[0096] As is clear from the results shown in Table 1, the paper towel rolls and paper towel sheets of Examples 1 to 12 were all good in terms of tear resistance, tactile feel, resistance to punctures, and water absorption. In contrast, the paper towel rolls and paper towel sheets of Comparative Examples 1 to 4 were all inferior in at least one of the following aspects: tear resistance, tactile feel, resistance to punctures, and water absorption. Therefore, it has been confirmed that the paper towel roll of the present invention is less prone to tearing due to its smooth surface with minimal irregularities, has a superior feel without roughness or stiffness, has good water absorption due to its high basis weight, and is strong and tear-resistant. [Explanation of symbols]

[0097] 1 paper towel roll 1a surface 1b back side 1e The outermost edge of the paper towel roll 1x Paper Towel Sheet 2 Paper tube 3 Films 10 Embossed Patterns 11. Radial embossing 12 Ring-closed structure embossing 13. Textured Pattern 20 test specimens 20a Corner 21 Holder 40a, 40b, 40c Paper Web 41 Headbox 42,43 Fabric 44 Foaming Roll 45 Through Air Dryer 46 Yankee Hair Dryer 50 Textured Fabric 51 Concave part 52 Convex part 60 pulp fibers 100 Linear embossed area 200 paper towel roll packaging

Claims

1. A paper towel roll is made by winding a paper towel sheet, which is made by laminating sheets in a 2-ply or 3-ply configuration, into a roll shape. The basis weight per ply of the aforementioned paper towel sheet is 40 g / m². ２ 80g / m or more ２ The following specifications apply to product plies with a paper thickness of 0.55 mm to 1.35 mm and a water absorption capacity per unit area of ​​the product ply of 350 g / m². ２ 810g / m or more ２ The following paper towel roll is characterized in that the root mean square height of the surface roughness on the surface side is 35 μm or more and 155 μm or less.

2. The specific volume of the aforementioned paper towel sheet is 8.8 cm³. ３ / g or more 22.0cm ３ The paper towel roll according to claim 1, characterized in that it is less than or equal to / g.

3. A paper towel roll according to claim 1 or 2, characterized in that the roll mass of the roll is 170g or more and 700g or less.

4. The paper towel roll according to claim 1 or 2, characterized in that at least one ply of the paper towel sheet is provided with a linear embossed pattern.

5. The paper towel roll according to claim 1 or 2, characterized in that the tensile strength DMDT in the MD direction per product ply of the paper towel sheet when dry is 2100 cN / 75 mm or more and 6500 cN / 75 mm or less.

6. The paper towel roll according to claim 1 or 2, characterized in that the tensile strength DCDT in the CD direction per product ply when dry is 2100 cN / 75 mm or more and 6200 cN / 75 mm or less of the paper towel sheet.

7. The paper towel roll according to claim 1 or 2, characterized in that the length of the roll is 18 m or more and 45 m or less.

8. The paper towel roll according to claim 1 or 2, characterized in that the water absorption per unit mass of the product ply of the paper towel sheet is 5.9 g / g or more and 13.0 g / g or less.

9. The roll density of the roll is 0.055 g / cm³. ３ 0.150g / cm or more ３ The paper towel roll according to claim 1 or 2, characterized in that it is as follows:

10. The winding density of the roll is 0.15 m / cm ２ or more and 0.60 m / cm ２ or less, and the paper towel roll according to claim 1 or 2, characterized in that.

11. A paper towel roll according to claim 1 or 2, characterized in that the roll's winding softness is 1.2 mm or more and 4.2 mm or less.

12. The paper towel roll according to claim 1 or 2, characterized in that the value calculated from (root mean square height of surface roughness on the surface side / basis weight per product ply) in the paper towel sheet is 0.30 or more and 4.50 or less.

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