JP2024005756A - paper towel roll - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a paper towel roll obtained by winding a paper towel sheet having excellent water absorption and strength around a paper tube using a pickup glue, which has a satisfactory winding state to the paper tube and is easily usable even in the sheet stuck with the pickup glue.

SOLUTION: There is provided a paper towel roll 1 obtained by winding a paper towel sheet 1x imparted with an embossment pattern and having a bending resistance of 6 mN or more and 26 mN or less around a paper tube 10 using a pickup glue 2 so as to be wound into a roll shape, in which the water supply amount per unit area of the paper towel sheet 1x is 230 g/m² or more and 600 g/m² or less, the basis weight per product ply is 30 g/m² or more and 54 g/m² or less, and a coating amount of the pickup glue 2 per roll width 280 mm is 0.1 g or more and 2.8 g or less.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

The present disclosure relates to a paper towel roll obtained by winding a paper towel sheet into a roll.

Paper towels have a variety of uses, such as cleaning oil stains around the kitchen, wiping dishes, and draining food. For these uses, paper towels are required to have sufficient water absorption and strength, and to achieve this, papermaking technologies have been developed that increase water and oil absorption and make the paper bulkier (increase basis weight). has been done.

Among these, the so-called TAD (Through Air Dryer) papermaking technology, which uses ventilation drying, produces a base paper with high water absorption and a soft texture, making it an excellent base paper for kitchen towel rolls. There is.

For example, Patent Document 1 discloses a textured layer of a textured belt for textured a wet fibrous web by pressing in a press section of a tissue papermaking machine that produces high-bulk tissue paper, comprising: The texturing layer is non-woven and has a web-carrying side with a surface that cooperates with the fibrous web, the texturing layer having depressions or raised areas forming a three-dimensional structure on its surface; A tissue papermaking machine including the same, as well as a method of manufacturing high bulk tissue paper produced using the same, is disclosed.

Further, U.S. Pat. , a non-creped, air-dried tissue sheet is disclosed having a cross-machine elongation of about 9 percent or greater and a basis weight of about 10 to 70 grams per square meter. It is also stated that a bulky and highly absorbent tissue sheet can be obtained by air drying.

Patent No. 5504169 Patent No. 3758702

For roll products such as paper towels, when winding a sheet onto a paper tube, in order to prevent wrinkles from occurring and to neatly wrap (wind) the sheet, the pickup (at the beginning of winding onto the paper tube) is Sometimes, glue is applied to adhere the tails (ends) of the sheet before rolling begins.
In the case of ordinary paper towels, it is possible to freely adjust the amount of glue used for pickup (hereinafter also referred to as pickup glue) and its composition, but as in the present application, paper towel rolls (sheets) that are bulky and have excellent water absorption ), the sheet absorbs a lot of glue, making it difficult for the sheet to adhere to the paper tube and making it difficult to wind it neatly onto the paper tube.

Furthermore, bulky paper towel rolls are thicker than regular paper towels, so they are less likely to bend (higher stiffness) and are more difficult to wrap around a core (paper tube). In particular, if the diameter of the paper tube is small, winding becomes more difficult. As a result, the sheet at the beginning of winding onto the paper tube is likely to wrinkle, resulting in a product that is likely to be defective.

On the other hand, increasing the amount of pickup glue applied will make it easier to wind up the sheet neatly, but when a sheet with pickup glue attached is wetted with water, the glue will dissolve and the sheet will become slimy, making it difficult to use.

Furthermore, if the glue application area (application width) is too small, the pick-up part will not adhere properly and the paper will not be wound neatly onto the paper tube. On the other hand, if the coating area is too large, the sheet may be difficult to peel off from the paper tube during use, or the sheet may be less easy to use when wet, as described above.

For the above reasons, it has been difficult to achieve both the ease of winding up a paper towel into a paper tube and the ease of use of a sheet with pick-up glue attached to the paper towel, which is bulky and has excellent water absorption properties.

Therefore, the present invention provides a paper towel roll in which a paper towel sheet with excellent water absorption and strength is wound onto a paper tube using pickup glue, which has a good winding condition on the paper tube and which has no pickup glue attached to it. The purpose is to provide a paper towel roll that is easy to use.

The inventor conducted extensive research and found that a paper towel sheet with an embossed pattern and a predetermined bending resistance was wound around a paper tube using pick-up glue, and the paper towel roll was wound into a roll. By keeping the amount of water absorbed per area, the basis weight per product ply, and the amount of pickup glue applied per roll width of 280 mm within the specified numerical range, the winding condition on the paper tube will be good and the pickup will be easy. Even a sheet with glue attached can be made into an easy-to-use paper towel roll, leading to the completion of the present invention. Specifically, the present invention provides the following.

(1) The first aspect of the present invention is a paper towel roll in which a paper towel sheet with an embossed pattern and a bending resistance of 6 mN or more and 26 mN or less is wound around a paper tube using pick-up glue and wound into a roll. The water absorption amount per unit area of the paper towel sheet is 230 g/m ² or more and 600 g/m ² or less, and the basis weight per product ply of the paper towel sheet is 30 g/m ² or more and 54 g/m ² The paper towel roll is as follows, and the amount of the pick-up glue applied per roll width of 280 mm is 0.1 g or more and 2.8 g or less.

(2) A second aspect of the present invention is the paper towel roll according to (1), wherein the paper towel sheet has an uneven pattern derived from a papermaking process that is different from the embossed pattern. That is.

(3) A third aspect of the present invention is the paper towel roll according to (1), wherein the value calculated from (outer diameter of the paper tube/bending resistance of the paper towel sheet) is 1.3 or more. It is characterized by being 8.5 or less.

(4) A fourth aspect of the present invention is the paper towel roll according to (1), characterized in that the pick-up glue has a coating width of 1.5 mm or more and 40 mm or less.

(5) A fifth aspect of the present invention is the paper towel roll according to (1), characterized in that the paper towel sheet has a specific volume of 7 cm ³ /g or more and 22 cm ³ /g or less. It is.

(6) A sixth aspect of the present invention is the paper towel roll according to (1), wherein the paper towel sheet has no embossing on the back side.

(7) A seventh aspect of the present invention is the paper towel roll according to (1), in which the paper towel sheet is folded along a folding line substantially parallel to the width direction of the roll so as to provide a tail portion, and The paper towel sheet on the outer winding side of the line is wound up while being adhered to the paper tube by the pickup glue.

(8) An eighth aspect of the present invention is the paper towel roll according to (7), characterized in that the length of the tail portion is 10 mm or more and 500 mm or less.

According to the present invention, in a paper towel roll in which a paper towel sheet having excellent water absorbency and strength is wound onto a paper tube using pickup glue, the winding condition on the paper tube is good and the sheet has no pickup glue attached. We can also provide paper towel rolls that are easy to use.

FIG. 1 is a perspective view of a paper towel roll according to an embodiment of the present invention. FIG. 2 is a perspective view showing the state of the pickup and tail portion of the paper towel roll of FIG. 1 at the beginning of winding. It is a figure which shows an example of the embossing pattern in the paper towel roll of this invention. FIG. 3 is a diagram showing a height profile on an XY plane using a microscope in shading. FIG. 3 is a graph showing a height profile on an XY plane measured by a microscope. FIG. 3 is a diagram showing how to determine the depth of embossing for an emboss pattern. FIG. 3 is a diagram showing the height profile of a non-embossed portion on an XY plane using a microscope in shading. FIG. 3 is a diagram showing a method for measuring water absorption of a paper towel roll of the present invention.

Hereinafter, embodiments of the present invention will be described in detail, but the following embodiments are presented for the purpose of illustration, and the present invention is not limited to the embodiments shown below.

<Paper towel roll>
FIG. 1 is a perspective view of a paper towel roll 1 according to an embodiment of the present invention. FIG. 2 is a perspective view showing a state in which the paper towel sheet 1x begins to be wound on the paper towel roll 1 of FIG. 1. As shown in FIG. 1, among the surfaces of the paper towel sheet 1x, the surface oriented toward the outside of the roll is referred to as the surface 1a (the surface of the paper towel sheet 1x), and the surface oriented toward the center of the roll is referred to as the back surface 1b (the surface of the paper towel sheet 1x). (back side).

As shown in FIGS. 1 and 2, the paper towel roll 1 according to the present embodiment includes a paper towel sheet 1x with an embossed pattern and a bending resistance of 6 mN or more and 26 mN or less, which is attached to a paper tube 10 ( This is a paper towel roll 1 which is wound around a core (hereinafter also referred to as a core) and wound into a roll shape. Note that the paper towel sheet 1x is preferably perforated in the roll width direction W at approximately equal intervals in the roll winding direction R (not shown).
Note that the number of plies of the paper towel sheet 1x is not particularly limited, but it is preferably 2 or 3 plies, and more preferably 2 plies.

The paper towel roll 1 is, for example, a roll of kitchen paper (sometimes referred to as paper towel, cooking paper, etc.) used for wiping off moisture or oil, removing dirt, etc. in home kitchens, restaurant kitchens, etc. (kitchen paper roll), other sanitary paper rolls, etc. In all of these, the pickup 3 is formed by applying pickup glue 2 along the roll width direction W to the inside of the winding start portion (tail portion 4) of the paper towel sheet 1x when manufacturing the roll body.

(pick up)
A pickup 3 of the paper towel roll 1 adheres the back surface 1b of the paper towel sheet 1x at the beginning of winding to a paper tube 10 in order to prevent the occurrence of wrinkles at the beginning of the winding of the paper towel roll 1 in the roll winding direction R. The pickup 3 is formed by applying pickup glue 2 along the roll width direction W to the winding start portion of the paper towel sheet 1x. For example, the pickup 3 can be formed by applying pickup glue 2 to the back surface 1b of the paper towel sheet 1x or the paper tube 10.
At this time, the pick-up glue 2 can be applied to the paper tube 10 facing the beginning of winding of the paper towel sheet 1x, so that the beginning of winding of the paper towel sheet 1x can be adhered to the paper tube 10. Alternatively, the pick-up glue 2 can be applied to the back side 1b of the roll start part of the paper towel sheet 1x to adhere the roll start part of the paper towel sheet 1x to the paper tube 10, but in particular, the pick-up glue 2 can be applied to the back side 1b of the roll start part of the paper towel sheet 1x. It is preferable to apply the adhesive to the paper tube 10 facing the roll start part of the paper towel sheet 1x to adhere the roll start part of the paper towel sheet 1x to the paper tube 10. In this embodiment, the pick-up glue 2 is applied continuously in a straight line along the roll width direction W, but the invention is not limited to this. For example, the pick-up glue 2 is applied a predetermined distance in the roll width direction W. The coating may be applied at a distance (not shown). In that case, the proportion of the area to which the pickup glue 2 is not applied in the roll width direction W is preferably 40% or less, more preferably 30% or less, still more preferably 20% or less, and most preferably 10% or less. % or less.

(Glue composition)
As the glue (pickup glue 2) for adhering the winding start portion of the paper towel roll 1 in the roll winding direction R, a known glue can be used, but it is preferable that it contains a water-soluble polymer. In addition, the concentration of components other than water (including water-soluble polymers and other auxiliary agents) contained in the glue is preferably 3% or more and 55% or less, more preferably 13% or more and 45% or less, and 23% or more and 35% or less. The following are more preferable. By setting the glue to the above concentration, the paper towel sheet 1x can be wrapped neatly during manufacturing as in the present application, and the paper towel roll 1 is easy to use even when the paper towel sheet 1x has pick-up glue 2 attached during use. be able to.

(Glue application position)
The pickup glue 2 is applied to a position (application position) spaced apart by a predetermined length L2 from the innermost edge 1d of the paper towel roll 1 in the roll winding direction R to the base end side in the roll winding direction R. That is, on the paper towel sheet 1x, a region (tail portion 4) that is not bonded to the paper towel roll 1 on the inside in the radial direction is provided on the roll start side in the roll winding direction R from the application location of the pickup glue 2 (pickup 3). It will be done. The length L2 (the above-mentioned predetermined length L2) of the tail portion 4 of the paper towel sheet 1x on the roll start side in the roll winding direction R from the application point of the pickup glue 2 (pickup 3) is 10 mm or more and 500 mm or less. The length is preferably 30 mm or more and 350 mm or less, and even more preferably 50 mm or more and 200 mm or less. By setting the length L2 of the tail portion 4 of the paper towel sheet 1x within the above numerical range, the paper towel sheet 1x and paper towel roll 1 can be wound into a paper tube 10 in a good state as in the present application. Further, the pickup glue 2 can be properly adhered.
In addition, the length L2 of the tail portion 4 of the paper towel sheet 1x is measured at a total of five points, including the center in the roll width direction W and positions 10% and 25% from both ends with respect to the roll width, and the average value and do.
Further, the manner in which the pickup 3 is adhered to the paper towel sheet 1x is not particularly limited as long as it is within the above numerical range of L2, but as shown in FIG. The paper towel sheet 1x on the outer winding side from the bending line 5 is bent along the approximately parallel bending line 5 so as to provide a tail portion 4 by the length of L2 in the direction of the roll winding direction R. It is preferable that the area (3) is wound around the paper tube 10 (including the tail portion 4) while being adhered to the paper tube 10 with the pick-up glue 2. Note that the bending line 5 may overlap the area of the pickup 3 (not shown), so that the pickup glue 2 may be slightly exposed on the surface layer of the paper tube 10 (in that case, the exposed pickup glue 2 is adhered to the back side 1b of the outer paper towel sheet 1x).

(Glue application width)
The application width L1 (length in the roll direction R of the pickup 3) of the pickup glue 2 according to the present embodiment is preferably 1.5 mm or more and 40 mm or less. This application width L1 refers to the length of the pickup glue 2 in the roll winding direction R. At this time, the length is measured at a total of five points, including the center in the roll width direction W and positions 10% and 25% from both ends with respect to the roll width, and the average value is taken as the length. If the application width L1 of the pickup glue 2 is less than 1.5 mm, the paper towel sheet 1x will not be neatly rolled up onto the paper tube 10. Moreover, if the application width L1 of the pickup glue 2 exceeds 40 mm, the paper towel sheet 1x to which the pickup glue 2 is attached will feel sticky when wet with water, making it difficult to use.
The coating width L1 of the pickup glue 2 is more preferably 4 mm or more and 26 mm or less, and even more preferably 6 mm or more and 17 mm or less.

(Amount of glue applied)
The amount of pick-up glue 2 applied per roll width of 280 mm is preferably 0.1 g or more and 2.8 g or less. If the coating amount is less than 0.1 g, the paper towel sheet 1x will not be neatly rolled up onto the paper tube 10. Furthermore, if the applied amount exceeds 2.8 g, the paper towel sheet 1x of the pickup 3 portion will feel sticky when wet, making it difficult to use.
The amount of pickup glue 2 applied per roll width of 280 mm is preferably 0.3 g or more and 1.7 g or less, and more preferably 0.4 g or more and 1.0 g or less. The amount of pick-up glue 2 applied per roll width of 280 mm means the amount of glue used per roll (per roll width of one roll). If the roll width is not 280 mm, it is converted to the value of the roll width of 280 mm by proportional calculation.

The amount of pickup glue 2 applied is measured by the following method. First, from a sample of the paper towel roll 1, the entire paper towel sheet 1x of the tail portion 4 including the portion where the pick-up glue 2 is applied is collected. At this time, in addition to the sheet of the tail portion 4, several rounds of the inner sheet are also sampled. Next, the same number (area) of sheets as the sheets collected above are collected from areas where the pickup glue 2 is not applied. Next, the weight of each sampled sheet is measured, and the amount of pick-up glue 2 applied per roll is calculated using the following calculation formula.
Amount of pickup glue 2 applied per roll = (Total weight of the sheet where pickup glue 2 is applied) - (Total weight of the sheet where pickup glue 2 is not applied)

(roll length and diameter)
The winding length of the paper towel roll 1 is preferably 14 m or more and 44 m or less, more preferably 21 m or more and 38 m or less, and even more preferably 25 m or more and 33 m or less. If the roll length is less than 14 m, the basis weight of the paper towel sheet 1x will be high in order to maintain a constant roll diameter DR, and as a result, a large amount of the pickup glue 2 will be absorbed, making it difficult to cleanly roll it onto the paper tube 10. It won't happen. Moreover, when the winding length exceeds 44 m, the basis weight of the paper towel sheet 1x becomes low in order to maintain a constant winding diameter, resulting in poor water absorption.

The roll length is measured as follows. First, the length of 10 paper towel sheets 1x between the perforations of the paper towel roll 1 is actually measured. Thereafter, the number of sheets in the paper towel roll 1 is actually measured, and the winding length is determined by proportional calculation from the length of 10 sheets and the number of sheets. For example, if the length of 10 sheets is 1.80 m and the number of sheets is 150 sheets, then 1.80 m x (150/10) = 27 m. Note that if the paper towel roll 1 does not have perforations, the roll length is actually measured.

It is preferable that the roll diameter DR of the paper towel roll 1 according to this embodiment is 110 mm or more and 189 mm or less. If the roll diameter DR is less than 110 mm, the basis weight of the paper towel sheet 1x will be low, resulting in poor water absorption. Moreover, if the winding diameter DR exceeds 189 mm, the basis weight of the paper towel sheet 1x becomes high, and as a result, a large amount of pickup glue 2 is absorbed, and the paper towel sheet 1x is not cleanly wound when it is wound onto the paper tube 10. The roll diameter DR of the paper towel roll 1 is more preferably 130 mm or more and 176 mm or less, and even more preferably 140 mm or more and 163 mm or less.

The winding diameter DR of the roll is actually measured using the Diameter Rule manufactured by Muratec KDS Co., Ltd. In the measurement, 10 paper towel rolls 1 are measured and the measurement results are averaged.

(sheet length)
The sheet length between perforations (the length of the paper towel sheet 1x in the roll direction R) is preferably 100 mm or more and 250 mm or less, more preferably 130 mm or more and 230 mm or less, and even more preferably 150 mm or more and 210 mm or less. If the sheet length is less than 100 mm, the amount of water absorbed per sheet will be reduced. When the sheet length exceeds 250 mm, the amount of water absorbed per paper towel sheet 1x with high absorbency as in the present application becomes larger than necessary.

(roll width and roll weight)
The roll width of the paper towel roll 1 is preferably 150 mm or more and 380 mm or less, more preferably 200 mm or more and 340 mm or less, and even more preferably 250 mm or more and 300 mm or less. If the roll width is less than 150 mm, the amount of water absorbed per sheet will be reduced. When the roll width exceeds 380 mm, the amount of water absorbed per paper towel sheet 1x with high absorbency as in the present application becomes larger than necessary.

Further, the roll weight of the paper towel roll 1 is preferably 160 g or more and 550 g or less, more preferably 230 g or more and 450 g or less, and even more preferably 270 g or more and 380 g or less. If the roll weight is less than 160 g, the basis weight of the paper towel sheet 1x will be low in order to maintain a constant winding length, resulting in poor water absorption. When the roll weight exceeds 550 g, the basis weight of the paper towel sheet 1x becomes high in order to maintain a constant winding length, and as a result, a large amount of the pickup glue 2 is absorbed, and the paper towel sheet 1x is not cleanly wound when it is wound onto the paper tube 10.

Note that the roll weight is the weight per roll width of 280 mm excluding the core (paper tube 10). If the roll width is not 280 mm, convert it to the weight per 280 mm by proportional calculation.

(roll density)
The roll density of the paper towel roll 1 according to this embodiment is preferably 0.04 g/cm ³ or more and 0.15 g/cm ^{3 or} less. If the roll density of the paper towel roll 1 is less than 0.04 g/cm ³ , the paper towel sheet 1x will have a low basis weight and poor water absorption. Furthermore, if the roll density of the paper towel roll 1 exceeds 0.15 g/ ^cm3 , the basis weight of the paper towel sheet 1x will increase as a result, and a large amount of the pickup glue 2 will be absorbed, making it difficult to cleanly roll up the paper towel sheet 1x onto the paper tube 10. It won't happen.

In addition, it is preferable that the roll density of the paper towel roll 1 is 0.05 g/cm ^<3> or more and 0.13 g/cm ^<3> or less, and it is more preferable that it is 0.06 g/cm ^<3> or more and 0.08 g/cm ^<3> or less.

Roll density is expressed as (roll weight)/(roll volume). The roll weight is the weight of the paper towel roll 1 per roll width of 280 mm. The roll volume is expressed as [{cross-sectional area of the outer diameter (rolling diameter DR) portion of the roll} - (cross-sectional area of the outer diameter DI portion of the paper tube 10)]×roll width (converted to around 280 mm) . For example, if the roll weight (excluding core) per roll width of 280 mm is 382 g, the roll diameter DR is 150 mm, and the paper tube outer diameter DI is 39 mm, the roll density = 382 g ÷ [{3.14 × (150 mm ÷ 2 ÷ 10 ) ² -3.14 x (39 mm ÷ 2 ÷ 10) ² } x (280 mm ÷ 10)] = 0.08 g/cm ³ .

(winding density)
The winding density of the paper towel roll 1 according to this embodiment is preferably 0.21 m/cm ² or more and 0.68 m/cm ² or less. If the winding density of the paper towel roll 1 is less than 0.21 m/cm ² , the paper towel sheet 1x will have a high basis weight, absorb much of the pickup glue 2, and will not be clean when wound onto the paper tube 10. . Moreover, when the winding density of the paper towel roll 1 exceeds 0.68 m/cm ² , the basis weight of the paper towel sheet 1x becomes low as a result, resulting in poor water absorption.

The winding density of the paper towel roll 1 is preferably 0.25 m/cm ² or more and 0.54 m/cm ² or less, more preferably 0.28 m/cm ² or more and 0.40 m/cm ² or less.

The winding density is expressed as (winding length x number of plies)/(cross-sectional area of roll). The cross-sectional area of the roll is expressed as {cross-sectional area of the outer diameter (rolling diameter DR) portion of the roll−(cross-sectional area of the paper tube outer diameter DI portion of the paper tube 10)}. For example, in the case of winding length 27 m, 2 plies, winding diameter DR 150 mm, paper tube outer diameter DI 39 mm, winding density = (27 m x 2) ÷ {3.14 x (150 mm ÷ 2 ÷ 10) ² - 3.14 x (39 mm) ÷2÷10) ² }=0.33m/ ^cm2 .

(core outer diameter)
Moreover, it is preferable that the paper tube outer diameter DI, which is the outer diameter of the paper tube 10 which is the core of the paper towel roll 1 of the present invention, is 28 mm or more and 58 mm or less. If the paper tube outer diameter DI is less than 28 mm, the paper towel sheet 1x having a predetermined bending resistance will not be rolled up neatly onto the paper tube 10 as in the present application. If the paper tube outer diameter DI exceeds 58 mm, the paper towel sheet 1x will have a lower basis weight and poor water absorption because the paper towel roll 1 has a constant winding diameter DR.
Note that the paper tube outer diameter DI is more preferably 33 mm or more and 53 mm or less, and even more preferably 38 mm or more and 48 mm or less.

The paper tube outer diameter DI is measured using the Diameter Rule manufactured by Muratec KDS Corporation. In the measurement, 10 paper towel rolls 1 are measured and the measurement results are averaged.

Furthermore, the weight of the paper tube 10 per roll width of 280 mm is preferably 9 g or more and 28 g or less, more preferably 12 g or more and 25 g or less, and even more preferably 15 g or more and 22 g or less.

<Paper towel sheet>
(Basic weight)
The basis weight per product ply of the paper towel sheet 1x according to the present embodiment is 30 g/m ² or more and 54 g/m ² or less. If the basis weight per product ply is less than 30 g/m ² , the paper towel sheet 1x will have poor water absorbency. Moreover, if the basis weight exceeds 54 g/m ² , the stiffness of the paper towel sheet 1x will increase as a result, and the paper towel sheet 1x will not be neatly rolled up into the paper tube 10. Moreover, the amount of water absorption increases, and the paper towel sheet 1x easily absorbs the pick-up glue 2, making it difficult to clean the paper towel sheet 1x when it is wound onto the paper tube 10. Here, the basis weight per product ply refers to the basis weight measured without changing the number of plies of the paper towel sheet 1x (without peeling or increasing the number of plies).
The basis weight can be measured based on JIS P 8124. The basis weight per product ply of the paper towel sheet 1x is preferably 34 g/m ² or more and 50 g/m ² or less, more preferably 38 g/m ² or more and 46 g/m ² or less.

Further, the basis weight of one ply of paper towel sheet 1x is preferably 14 g/m ² or more and 28 g/m 2 or less, and 16 g/m ² or more and 26 g/m 2 or less for both the front surface ¹ a and the back surface ¹ b. More preferably, it is 18 g/m ² or more and 24 g/m ² or less. The basis weight of one ply is determined by measuring the basis weight per ply of the product, then peeling off the ply, measuring the weight of the front side 1a and the back side 1b, and calculating the basis weight of the front side 1a and the back side 1b from the weight ratio. .
In addition, when the paper towel sheet 1x has 3 plies, the basis weight of one ply of the middle layer is preferably 10 g/m ² or more and 20 g/m ² or less, and preferably 11 g/m ² or more and 18 g/m ² or less. More preferably, it is 12 g/m ² or more and 16 g/m ² or less. Similarly to the case of two plies, the basis weight of one ply of the middle layer is calculated by measuring the weight of each side after peeling and calculating the weight ratio.

Furthermore, in the paper towel sheet 1x, the difference between the basis weight of the front surface 1a and the basis weight of the back surface 1b is preferably 2 g/m ² or less. The pickup glue 2 is applied to the back side 1b, but if the basis weight of the front side 1a is made too high than the back side 1b, it becomes difficult to use when the sheet on the back side 1b is wetted with water. On the other hand, if the basis weight of the front surface 1a is too lower than the basis weight of the back surface 1b, winding onto the paper tube 10 may not be done neatly, resulting in a defective product. Note that the difference between the basis weight of the front surface 1a and the basis weight of the back surface 1b is more preferably 1 g/m ² or less, and even more preferably 0.5 g/m ² or less.

(bending resistance)
The bending resistance of the paper towel sheet 1x according to the present embodiment is 6 mN or more and 26 mN or less. If the bending resistance of the paper towel sheet 1x is less than 6 mN, the basis weight and strength of the paper towel sheet 1x will be low, and the water absorbency will be poor. Moreover, if the bending resistance of the paper towel sheet 1x exceeds 26 mN, the stiffness of the paper towel sheet 1x will increase and it will not be neatly rolled up onto the paper tube 10.
The bending resistance of the paper towel sheet 1x is preferably 9 mN or more and 21 mN or less, more preferably 10 mN or more and 18 mN or less.

The bending resistance of the paper towel sheet 1x can be measured using an L&W bending tester (manufactured by Lorentzen & Wettre) in accordance with the method described in JIS P 8125-1:2017 (ISO2493). The bending resistance (load ).

Note that if the interval between the perforations of the sheet is too short to collect a test piece with a length of 100 mm, the length of the test piece can be shortened.

Also, a value calculated from dividing the paper tube outer diameter DI of the paper tube 10 of the paper towel roll 1 by the bending resistance of the paper towel sheet 1x (paper tube outer diameter DI of the paper tube 10/bending resistance of the paper towel sheet 1x). is preferably 1.3 or more and 8.5 or less. If the value is less than 1.3, the bending resistance of the paper towel sheet 1x against the paper tube 10 is high and the paper towel sheet 1x will not be rolled up neatly onto the paper tube 10. If the value exceeds 8.5, the bending resistance of the paper towel sheet 1x relative to the paper tube 10 is low, that is, the basis weight is low, resulting in poor water absorption.
The value calculated from (paper tube outer diameter DI of paper tube 10/bending resistance of paper towel sheet 1x) is more preferably 2.0 or more and 5.5 or less, and 2.4 or more and 4.5 or less. It is more preferable that

(paper thickness)
The paper thickness of the paper towel sheet 1x is preferably 1.9 mm/10 sheets or more and 4.5 mm/10 sheets or less, more preferably 2.1 mm/10 sheets or more and 3.9 mm/10 sheets or less, and 2. It is more preferable that the thickness is .6 mm/10 sheets or more and 3.7 mm/10 sheets or less. If the paper thickness is less than 1.9 mm/10 sheets, the paper towel sheet 1x will have poor water absorbency, and if it exceeds 4.5 mm/10 sheets, the stiffness of the paper towel sheet 1x will increase as a result, and it will be wound onto the paper tube 10. It doesn't clean properly.
Paper thickness can be measured using a thickness gauge (dial thickness gauge "PEACOCK" manufactured by Ozaki Seisakusho Co., Ltd.). The measurement conditions were a measurement load of 37.85 gf/cm ² and a probe diameter of 30 mm. A sample was placed between the probe and the measuring stand, and the gauge was read when the probe was lowered at a rate of 1 mm or less per second. The sample is 10 paper towel sheets (1x for 2 plies, 3 sets for 3 plies, and the value is calculated as 10 sets by proportional calculation) for measurement. In addition, the measurement is repeated 10 times at different locations and the measurement results are averaged.

(embossed pattern)
The paper towel roll 1 (paper towel sheet 1x) of the present invention is embossed and has an embossed pattern. Moreover, the paper towel sheet 1x in the present invention is laminated in the case of two or more plies after the sheet is embossed. When laminating, plybond glue is used to apply glue and perform adhesion processing.
Plybond glue is applied to the back side of the embossed part of the front side 1a side of the 2-ply paper towel sheet 1x (between the 2-ply front side 1a sheet and the back side 1b side sheet), and then both sheets are Lamination is preferred. In the case of 3-ply, it is also possible to emboss two layers on the front side 1a side and apply glue to the back side of the middle layer, or to emboss one layer on the front side 1a side and apply glue to the back side of the layer on the front side 1a side. Although it is possible to apply glue to the surface, it is preferable to embossing the two layers on the front side 1a and apply glue to the back side of the middle layer. By adhering in this manner, the paper towel sheet 1x and the paper towel roll 1 that can be wound around the paper tube 10 in a good state can be obtained as in the present application. Further, the pickup glue 2 can be properly adhered.

An embossed pattern is applied to the ply on the surface 1a of the paper towel sheet 1x. By applying the embossed pattern to the surface 1a, it is possible to apply glue to the embossed portion and laminate two or more plies. Furthermore, although an embossing may be provided on the back surface 1b, it is preferable that no embossing is provided. By not providing an embossing (no unevenness of the sheet due to the embossing), it becomes easier to uniformly apply the pick-up glue 2 to the back surface 1b. The emboss pattern is not particularly limited as long as it is a pattern commonly applied to paper towels, such as a dot pattern or a line pattern, but a linear emboss pattern is particularly preferable. Specifically, as a linear emboss pattern, as shown in Fig. 3, one pattern consists of a substantially circular shape with other patterns inside, and an overall pattern with approximately lines on the top, bottom, left and right. The pattern is not particularly limited as long as it is symmetrical and includes two figures of two types each including a combination of a plurality of curves and figures. Regarding the substantially circular shape, it is preferable that the substantially circular shape is doubled.

Regarding the dimensions of the embossed pattern, it is preferable that the rectangle E surrounding the embossed pattern (E is not an embossed pattern) is a square with sides of 2 cm or more and 25 cm or less, and it is a square with sides of 5 cm or more and 20 cm or less. is more preferable, and even more preferably a square with sides of 8 cm or more and 15 cm or less. Regarding this rectangle E, the vertical direction is preferably parallel to the roll winding direction of the paper towel roll 1, and the horizontal direction is preferably parallel to the width direction of the paper towel roll 1, but it may be inclined. By using such a pattern, the water absorption amount can be improved in the paper towel sheet 1x having a high water absorption amount as in the present application. Further, the pickup glue 2 can be properly adhered.

At this time, for linear emboss patterns with a thickness of 0.1 mm or more and 4 mm or less and a length of 5 mm or more, the total length of the emboss is 50 cm/100 cm ² or more 550 cm/ It is preferably 100 cm ² or less, more preferably 80 cm/100 cm ² or more and 410 cm/100 cm ² or less, and even more preferably 110 cm/100 cm ² or more and 300 cm/100 cm ² or less.

The above total length is the emboss length for an emboss with a thickness of 0.1 mm or more and 4 mm or less and a length of 5 mm or more inside the rectangle E that includes all one emboss pattern as shown in Figure 3. Measure the total length by adding up the total length, and use it as the total length per 100 ^cm2 . The size of one side of this quadrangle E can be changed as appropriate depending on the size of the embossed pattern. If a rectangle containing all embossed patterns includes an embossed pattern adjacent to the embossed pattern included in the rectangle, the length of the adjacent embossed pattern is also measured and included in the total length. Furthermore, if the size of one side of the square E cannot be clearly determined based on the emboss pattern, the size of the square E is set to 10×10 cm, and the total length of the emboss included in the square E is measured. By setting the total length within the above range, the water absorption amount can be improved in the paper towel sheet 1x having a high water absorption amount as in the present application. Further, the pickup glue 2 can be properly adhered. The total length is determined by actual measurements using the method described above. Note that the measurement may be performed using a general microscope.

In the emboss pattern, the depth of the emboss is preferably 0.06 mm or more and 1.05 mm or less, more preferably 0.10 mm or more and 0.55 mm or less, and 0.14 mm or more and 0.35 mm or less. is even more preferable. If the depth of the embossing is less than 0.06 mm, the adhesion between the plies and the adhesion to the paper tube 10 will be weak, and the paper will not be neatly rolled up onto the paper tube 10. Moreover, if the depth of the embossing exceeds 1.05 mm, the paper towel sheet 1x will be crushed, resulting in poor water absorption.

The depth of embossing is measured using a microscope. As the microscope, the product name "One-shot 3D measurement macroscope VR-3100" manufactured by KEYENCE can be used. The product name "VR-H1A" can be used as microscope image observation/measurement/image analysis software. Further, the measurement conditions are a magnification of 25 times and a visual field area of 12 mm x 9 mm. The measurement magnification and visual field area may be changed as appropriate depending on the desired size of the embossing.

FIG. 4 shows a height profile on the XY plane obtained using a microscope, and the height of the surface of the paper towel sheet 1x is expressed in shading. The linear parts in FIG. 4 whose shading is different from the surrounding areas indicate individual embossings. The depth of the emboss is determined by measuring the height difference of the emboss using the microscope. Note that the measurement is performed on the surface 1a side of the paper towel sheet 1x. Further, at the time of measurement, three rounds of the paper towel sheet 1x are removed from the paper towel roll 1, and the fourth round of the paper towel sheet 1x is used to measure the sheet state without changing the number of plies. Also, if there are perforations, avoid them when measuring.

First, line segment AB is drawn as shown in FIG. 4 to obtain the height profile shown in FIG. Note that the line segment AB may be drawn across the embossing. In addition, line segment AB is drawn so that it is in the roll width direction W (CD direction) of the paper towel sheet 1x, but the spacing between the embossings is narrow, for example, 2 mm or less, and the height of the convex portions described below becomes low. In this case, the line segment may be drawn diagonally or in the roll winding direction R. The height profile is a (measured) cross-sectional curve S1 that represents the unevenness of the sample surface of the actual paper towel sheet 1x, but noise (fiber lumps on the surface of the paper towel sheet 1x, fibers extending like whiskers, etc.) These noise peaks must be removed when calculating the difference in height between concavities and convexities.

Therefore, the filter size of the weighted average radio button is set to ±12 for the (measured) cross-sectional curve S1 in FIG. 5, and the smoothed cross-sectional curve S2 in FIG. 6 is obtained. Note that smoothing using the weighted average radio button filter can be automatically obtained using the above analysis software. Then, in the graph shown in FIG. 6, the average value of the maximum value of each of the vertical axes of the convex part H1 and the convex part H2 adjacent to the convex part H1 is calculated, and The minimum value of the vertical axis in the recess D1 is determined. The value obtained by subtracting the minimum value from the average value of the maximum values obtained in this manner is set as the provisional embossing depth. Then, as shown in FIG. 6, similar measurements are performed at two consecutive locations on the cross-sectional curve (a total of two consecutive locations: the concave portion D1 and the concave portion D2 sandwiched between the convex portions H3 and H4). (Two measurements are obtained at this point). After that, the paper towel roll 1 was rotated 90 degrees three times in the roll winding direction R of the paper towel sheet 1x, and the same measurements as above were performed at each position (the measurement positions in the roll winding direction R were 4 in total). ), the average value of a total of 8 locations (2×4) is finally adopted as the embossing depth.

In addition, since the paper towel sheet 1x of the present invention has an uneven pattern derived from the papermaking process that is different from the embossed pattern, there is variation in the height of the left and right protrusions sandwiching the recess. Therefore, if there is a difference of 0.2 mm or more in the vertical axis values between a convex part that sandwiches a concave part and a convex part (for example, a convex part H3 and a convex part H4 that sandwich a concave part D2), measure at a location that avoids that part. conduct.

There is no particular restriction on whether or not the back surface 1b of the paper towel sheet 1x has an embossed pattern, as long as it has an uneven pattern derived from the papermaking process that is different from the embossed pattern. It may be nested embossed or pin-to-pin embossed or not embossed, but preferably nested embossed or no embossed, more preferably no embossed. Conventional paper towels use pin-to-pin or nested formats to ensure water absorption, but when thick base paper is used as in the present application, the embossment prevents the paper from being crushed. This may result in a decrease in water absorption. For this reason, it is preferable that the front surface 1a has linear embossing and the back surface 1b has no embossing. By not providing an embossing, the pick-up glue 2 can be uniformly applied and winding onto the paper tube 10 can be improved.

At this time, the root mean square height Sq of the surface roughness in the portion of the paper towel sheet 1x to which the embossed pattern is not provided (hereinafter also referred to as non-embossed portion) is preferably 35 μm or more, and 50 μm or more and 150 μm or less. It is more preferably 60 μm or more and 120 μm or less, and most preferably 70 μm or more and 100 μm or less. When the root mean square height Sq of surface roughness is less than 35 μm, the paper towel sheet 1x has poor absorbency. Further, the upper limit of the root mean square height Sq of the surface roughness is not particularly limited, but if the value is too high, the paper towel sheet 1x may not be clean when wound around the paper tube 10.

The root mean square height Sq of the surface roughness of the non-embossed portion is measured using a microscope. As for the microscope, the product name "One Shot 3D Measurement Macroscope VR-3100" manufactured by KEYENCE can be used, as in the case of the emboss depth described above. The product name "VR-H1A" can be used as microscope image observation/measurement/image analysis software. Further, the measurement conditions are a magnification of 38 times and a visual field area of 8 mm x 6 mm. The measurement magnification and visual field area may be changed as appropriate depending on the desired size of the embossing.

FIG. 7 is a diagram showing the height profile of the non-embossed portion on the XY plane using a microscope in shading.

For the obtained image shown in FIG. 7, a filter is set in the same way as for the emboss depth described above. Specifically, by setting the S-filter (low-pass filter), components with a scale smaller than the cutoff wavelength can be set, and by setting the L-filter (high-pass filter), components with a scale larger than the cutoff wavelength can be detected. Remove from the image. Here, the S-filter is 500 μm, and the L-filter is 8 mm. If the S-filter and L-filter are selected, the root mean square height Sq is automatically calculated.

As with the emboss depth, the non-embossed area is measured by removing three rounds of the paper towel sheet 1x from the paper towel roll 1, using the fourth round of the paper towel sheet 1x, and measuring that sheet without changing the number of plies. Also, if there are perforations, avoid them when measuring. The paper towel roll 1 was measured at two locations in the roll width direction W, and then the paper towel roll 1 was rotated 90 degrees three times in the roll winding direction R, and the same measurements as above were performed at each position (roll winding direction The number of measurement positions in R is 4 in total), and the average value of a total of 8 locations (2×4) is finally adopted as the root mean square height Sq.
The locations to be measured are those on the back surface 1b side of the paper towel sheet 1x and the embossed pattern portion on the front surface 1a side of the paper towel sheet 1x where the ply is not adhered by ply bond glue.

(Water absorption amount)
In the present invention, the water absorption amount per unit area of the paper towel sheet 1x is 230 g/m ² or more and 600 g/m ² or less. If the amount of water absorbed per unit area is less than 230 g/m ² , the paper towel sheet 1x will have poor water absorption. Furthermore, if the amount of water absorbed per unit area exceeds 600 g/m ² , the paper towel sheet 1x will absorb a large amount of the pickup glue 2 and will not be clean when wound onto the paper tube 10.
The water absorption amount per unit area of the paper towel sheet 1x is preferably 270 g/m ² or more and 550 g/m ² or less, more preferably 330 g/m ² or more and 480 g/m ² or less.

Moreover, it is preferable that the water absorption amount per unit weight of the paper towel sheet 1x is 6.0 g/g or more. If the amount of water absorbed per unit weight is less than 6.0 g/g, the paper towel sheet 1x will have poor water absorption. There is no particular upper limit to the amount of water absorbed per unit weight, but if it is too high, the paper towel sheet 1x will absorb a lot of the pickup glue 2, and the paper towel sheet 1x will not be clean when wound onto the paper tube 10. The amount of water absorbed per unit weight is more preferably 7.0 g/g or more and 14.0 g/g or less, and even more preferably 8.0 g/g or more and 12.0 g/g or less.

Furthermore, the amount of water absorption (per unit area) between two plies of paper towel sheet 1x (if the paper towel sheet 1x has 3 plies, the amount of water absorption at two places between the plies) is 110 g/m ² or more 300 g/m It is preferably ² or less, more preferably 130 g/m ² or more and 280 g/m ² or less, and even more preferably 160 g/m ² or more and 260 g/m ² or less. By setting the water absorption amount (per unit area) of the paper towel sheet 1x within the above numerical range, the paper towel sheet 1x and the paper towel roll 1 can be wound into a paper tube 10 in a good state as in the present application. . Further, the pickup glue 2 can be properly adhered.
At this time, the water absorption amount (per unit area) between the two plies of the paper towel sheet 1x is calculated from the water absorption amount per unit area of the paper towel sheet 1x to the water absorption amount per unit area of 1 ply (surface 1a), which will be described later. This is the value obtained by subtracting the amount of water absorbed per unit area of one ply (back side 1b). In addition, when the paper towel sheet 1x is 3-ply, the value is obtained from the following formula.
Water absorption amount between 3 plies per unit area = Water absorption amount of 3 plies - Water absorption amount of 1 ply (front side 1a) - Water absorption amount of 1 ply (back side 1b) - Water absorption amount of 1 ply (middle layer)

In addition, each amount of water absorption when the paper towel sheet 1x has 2 plies is measured as follows.

First, a 2-ply stacked paper towel sheet 1x is taken and cut using a square template with each piece measuring 7.6 cm (3 inches) to produce a rectangular test piece with each side 7.6 cm. Measure the weight of the test piece before water absorption using an electronic balance. Set the test piece in a holder (a jig that fixes the test piece at three points; the jig is made of metal that does not absorb moisture).

Next, distilled water is poured into a commercially available vat to a depth of 2 cm, and the test piece set in the holder is immersed in the distilled water for 2 minutes. After 2 minutes of immersion, the test piece is taken out from the distilled water together with the holder, and a band 210 is attached to one corner 200d of the test piece 200, as shown in FIG. The band 210 is made by peeling the same paper towel as the two plies of paper towel to be measured into one ply, cutting the one ply of paper towel into a size of 3 mm x length 38 mm, and peeling it from the corner 200d of the test piece 200 toward the center. Paste it on the 6mm part. Next, the holder 220 and the test piece 200 are hung from a rod installed in an empty water tank with the corner 200a facing the corner 200d facing upward, and the lid of the water tank is closed and left for 15 minutes.
Thereafter, the holder 220 and the test piece 200 are taken out from the water tank, the band 210 and the holder 220 are removed, and the weight of the test piece 200 is measured using an electronic balance. From the weight change of the test piece 200 before and after immersing it in distilled water, the water absorption amount of distilled water per unit area of the test piece 200 (g of water/m ² of sheet, per 1 m ² , abbreviated as g/m ² ). Calculate. Furthermore, by dividing the amount of water absorption per unit area (g water/m ² of sheet) by the basis weight of the product ply of test piece 200, the amount of water absorption per unit area (g of water/m ² of sheet)/basis weight (sheet g/sheet m ² ) = water absorption amount per unit weight (water g/sheet g, per 1 g, abbreviated as g/g). Measurement is performed five times for each sample, and the average value is used.

The amount of water absorbed by one ply was determined by cutting 1 x paper towel sheet stacked on 2 plies into a 7.6 x 7.6 cm (3 inch) square to create a test piece 200, and then peeling off the ply. This is used as a test piece 200 for measuring the water absorption amount of one ply. The measurement method is the same as for 2 ply.
When the paper towel sheet 1x has one ply, it is used as the sample piece 200 without being peeled off, and the measurement is carried out in the same manner as in the case of two plies. In the case of 3 ply, measure in the same way as in the case of 2 ply.

This measurement is performed in accordance with JIS P 8111 method at a temperature of 23±1° C. and a humidity of 50±2%. Further, distilled water is maintained at 23±1°C.

In addition, in the present invention, the water absorption amount per unit area of 1 ply (surface 1a) of 1x paper towel sheet is preferably 50 g/m ² or more and 170 g/m ² or less, and 60 g/m ² or more and 160 g/m ² or less. More preferably, it is 70 g/m ² or more and 150 g/m ² or less. On the other hand, the water absorption amount per unit area of 1 ply (back side 1b) of 1x paper towel sheet is preferably 52 g/m ² or more and 172 g/m ² or less, and 62 g/m ² or more and 162 g/m ² or less. More preferably, it is 72 g/m ² or more and 152 g/m ² or less.

Further, the water absorption amount per unit weight of 1 ply (surface 1a) of the paper towel sheet 1x is preferably 3.0 g/g or more, more preferably 3.5 g/g or more and 7.0 g/g or less. , more preferably 4.0 g/g or more and 6.0 g/g or less. On the other hand, the water absorption amount per unit weight of 1 ply (back side 1b) of paper towel sheet 1x is preferably 3.1 g/g or more, and preferably 3.6 g/g or more and 7.1 g/g or less. More preferably, it is 4.1 g/g or more and 6.1 g/g or less.

(specific volume)
The specific volume of the paper towel sheet 1x is preferably 7 cm ³ /g or more and 22 cm ³ /g or less. When the specific volume of the paper towel sheet 1x is less than 7 cm ³ /g, the paper towel sheet 1x has poor water absorbency. Moreover, if the specific volume of the paper towel sheet 1x exceeds 22 cm ³ /g, the stiffness of the paper towel sheet 1x will increase and it will not be clean when wound up onto the paper tube 10.
The specific volume of the paper towel sheet 1x is more preferably 9 cm ³ /g or more and 20 cm ³ /g or less, and even more preferably 12 cm ³ /g or more and 17 cm ³ /g or less. The specific volume is calculated by dividing the paper thickness per ply of the paper towel sheet 1x by the basis weight per ply, and is expressed as the volume cm ³ per unit g.

(DMDT and DCDT)
The tensile strength DMDT (Dry Machine Direction Tensile Strength) of the paper towel sheet 1x in the longitudinal direction (MD direction: roll winding direction R) when dry based on JIS P 8113 must be 6 N/25 mm or more and 15 N/25 mm or less. Preferably, the tensile strength DCDT (Dry Cross Direction Tensile Strength) in the transverse direction (CD direction: roll width direction W) during drying is preferably 6 N/25 mm or more and 15 N/25 mm or less. If DMDT or DCDT is less than 6N/25mm, the basis weight of the paper towel sheet 1x will be low as a result, and the water absorbency will be poor. If DMDT or DCDT exceeds 15 N/25 mm, the stiffness of the paper towel sheet 1x will increase and it will not be clean when wound up onto the paper tube 10.

Note that the DMDT is more preferably 7 N/25 mm or more and 13 N/25 mm or less, and even more preferably 8 N/25 mm or more and 12 N/25 mm or less. Further, the DCDT is more preferably 7 N/25 mm or more and 13 N/25 mm or less, and even more preferably 8 N/25 mm or more and 12 N/25 mm or less.

Further, the ratio of DMDT to DCDT (DMDT/DCDT) is preferably 0.8 or more and 1.4 or less, more preferably 0.9 or more and 1.3 or less, and 1.0 or more and 1.2 or less. It is more preferable that The DMDT/DCDT of general paper towels is about 2.0 to 4.0, but in the case of highly absorbent paper towels like the one in this application, by setting the DMDT/DCDT in the above range, it becomes difficult to tear in the DCDT direction, and when used. The paper towel roll 1 can be made such that the paper towel sheet 1x can be easily peeled off without tearing even when the pickup 3 is peeled off.

(WMDT and WCDT)
Further, it is preferable that the paper towel sheet 1x has a wet longitudinal tensile strength WMDT (Wet Machine Direction Tensile Strength) of 1.5 N/25 mm or more and 8.0 N/25 mm or less based on the old JIS S 3104, and It is preferable that the wet cross direction tensile strength WCDT (Wet Cross Direction Tensile Strength) is 1.4 N/25 mm or more and 7.9 N/25 mm or less. When both WMDT and WCDT are within the above numerical ranges, the paper towel sheet 1x and paper towel roll 1 can be wound into a paper tube 10 in a good state as in the present application. Further, the pickup glue 2 can be properly adhered.

Note that the WMDT is more preferably 2.0 N/25 mm or more and 6.0 N/25 mm or less, and even more preferably 2.5 N/25 mm or more and 4.5 N/25 mm or less. Further, the WCDT is more preferably 1.9 N/25 mm or more and 5.9/25 mm or less, and even more preferably 2.4 N/25 mm or more and 4.4 N/25 mm or less.

Further, the ratio of WMDT to WCDT (WMDT/WCDT) is preferably 0.8 or more and 1.4 or less, more preferably 0.9 or more and 1.3 or less, and 1.0 or more and 1.2 or less. It is more preferable that

<How to manufacture paper towel sheets and paper towel rolls>
The paper towel sheet 1x and the paper towel roll 1 can be manufactured, for example, in the following order: (1) paper making and creping, (2) embossing, (3) pick-up glue application and adhesion, and (4) roll winding. In the manufacturing (paper making) process, it is preferable to use TAD paper making technology. At this time, in the papermaking process, it is preferable that an uneven pattern derived from the papermaking process (fabric) that is different from the above-mentioned emboss pattern is applied to the paper towel sheet 1x. By having this uneven pattern, the water absorption amount of the paper towel sheet 1x is further increased. Note that "originating from the papermaking process" means that it is applied during the papermaking process of 1x paper towel sheet between the head box of the paper machine and the inlet of the Yankee dryer, especially when the sheet is dried together with the fabric in the through air dryer section. As a result, unevenness is formed.

Further, the pattern of the unevenness can be changed as appropriate by changing the pattern of the fabric (fine pattern, rough pattern). Although the specific volume (paper thickness) changes when the uneven pattern is changed, it is preferable to select a pattern such that the specific volume (paper thickness) of the base paper falls within the numerical range described below. Further, it is preferable to select a pattern such that the root mean square height Sq of the surface roughness of the non-embossed portion of the paper towel sheet 1x falls within the above numerical range.

When using a base paper made using this through-air dryer, it is preferable that the area ratio of the convex portions on the embossing roll for applying the embossing pattern is 4% or more and 35% or less. If the area ratio is less than 4%, the paper towel sheet 1x will absorb a large amount of the pick-up glue 2, and the paper towel sheet 1x will not be clean when wound onto the paper tube 10. When the area ratio exceeds 35%, the paper towel sheet 1x has poor water absorbency.

The area ratio of the convex portions is more preferably 6% or more and 25% or less, and even more preferably 9% or more and 18% or less. Further, the shape of the convex portion and the emboss alone may be circular, oval, rectangular, square, floral pattern, logo, letters, etc. without particular limitation, but as mentioned above, linear embossing is preferred. This embossing is preferably provided only on the surface 1a of the paper towel sheet 1x, as described above.

At this time, the basis weight of the two plies of base paper used for manufacturing the paper towel sheet 1x (the basis weight of one ply is doubled) is preferably 31 g/m ² or more and 55 g/m ² or less, and 35 g/m 2 or more. It is more preferably ² or more and 51 g/m ² or less, and even more preferably 39 g/m ² or more and 47 g/m ² or less. Further, the paper thickness is preferably 2.0 mm/10 sheets or more and 5.0 mm/10 sheets or less, more preferably 2.2 mm/10 sheets or more and 4.5 mm/10 sheets or less, and 2.7 mm/10 sheets or more. It is more preferable that the number of sheets is 10 or more and 4.2 mm/10 or less. Furthermore, the specific volume is preferably 8 cm ³ /g or more and 25 cm ³ /g or less, more preferably 10 cm ³ /g or more and 23 cm ³ /g or less, and 12 cm ³ /g or more and 21 cm ³ /g or less. More preferably.

It goes without saying that the present invention is not limited to the embodiments described above, but extends to various modifications and equivalents that fall within the spirit and scope of the present invention.

(1) Paper making and creping (Comparative Example 6 used a general Yankee dryer (YD) without using TAD), (2) Embossing, (3) Pick-up glue application and adhesion, (4) Roll winding Through the removal process, paper towel sheets and paper towel rolls of Examples 1 to 14 and Comparative Examples 1 to 6 were manufactured. The above-mentioned parameters were measured for the paper towel rolls of all Examples and Comparative Examples, and the following evaluations were performed. Note that all embossing was provided only on the front side of the paper towel sheet.

The produced paper towel sheets and paper towel rolls were evaluated on the following three items (neatness of winding of the sheet onto a paper tube, water absorption, and tackiness when wet).

(Cleanliness of sheet winding on paper tube)
Of the 30 manufactured paper towel rolls, the number of rolls with wrinkled sheets at the beginning of the roll was counted and evaluated on a five-point scale. The evaluation criteria are as follows.
◎ : 0 to 1 rolls have wrinkled sheets at the beginning of winding ○ : 2 to 4 rolls have wrinkled sheets at the beginning of winding △ : Rolls have wrinkled sheets at the beginning of winding 5 to 7 rolls×: 8 to 14 rolls with wrinkled sheets at the beginning of winding××: 15 or more rolls with wrinkled sheets at the beginning of winding

(Water absorption)
The amount of water absorbed per unit area of the paper towel sheet after production was actually measured and evaluated on a five-point scale. The evaluation criteria are as follows.
◎: 330 g/m ² or more ○: 270 g/m ² or more and 330 g/m ² or less △: 230 g/m ² or more and 270 g/m ² or more ×: 170 g/m ² or more and 230 g/m ² or more Time XX: Less than 170g/ ^m2

(Adhesive feeling when wet)
Thirty monitors sensory-evaluated the adhesive feel of the area adhered with pickup glue when the paper towel sheet was wetted with water and was evaluated on a four-point scale based on the number of people who felt it had a "sticky feel." The evaluation criteria are as follows.
◎ : 0 to 2 people felt it had a "sticky feeling" ○ : 3 to 5 people felt it had a "sticky feeling" △ : 6 to 10 people felt it had a "sticky feeling" People ×: 11 or more people felt that it had a “sticky feeling”

The results obtained are shown in Tables 1 and 2.

From the above, the paper towel roll of the present invention is a paper towel roll in which a paper towel sheet with excellent water absorption and strength is wound around a paper tube using pickup glue, and the winding condition on the paper tube is good, and the pickup glue is It can be seen that the paper towel roll is easy to use even when the sheet is attached.

1 Paper towel roll 1a Front side 1b Back side 1c Outermost edge of paper towel roll 1d Innermost edge of paper towel roll 1x Paper towel sheet 2 Pickup glue 3 Pickup 4 Tail part 5 Bending line 10 Paper tube 200 Test piece 200a, 200d Corner Part 210 Obi 220 Holder

Claims (8)

A paper towel roll in which a paper towel sheet with an embossed pattern and a bending resistance of 6 mN or more and 26 mN or less is wound around a paper tube using pick-up glue and wound into a roll shape,
The water absorption amount per unit area of the paper towel sheet is 230 g/m ² or more and 600 g/m ² or less,
The paper towel sheet has a basis weight per product ply of 30 g/m ² or more and 54 g/m ² or less,
A paper towel roll, characterized in that the amount of the pick-up glue applied per roll width of 280 mm is 0.1 g or more and 2.8 g or less. The paper towel roll according to claim 1, wherein the paper towel sheet has an uneven pattern derived from a papermaking process that is different from the embossed pattern. The paper towel roll according to claim 1, wherein a value calculated from (outer diameter of the paper tube/bending resistance of the paper towel sheet) is 1.3 or more and 8.5 or less. The paper towel roll according to claim 1, wherein the pick-up glue has a coating width of 1.5 mm or more and 40 mm or less. The paper towel roll according to claim 1, wherein the paper towel sheet has a specific volume of 7 cm ³ /g or more and 22 cm ³ /g or less. The paper towel roll according to claim 1, wherein the paper towel sheet has no embossing on the back side. the paper towel sheet is bent along a folding line substantially parallel to the roll width direction to provide a tail portion;
2. The paper towel roll according to claim 1, wherein the paper towel sheet on the outer winding side from the bending line is wound while being adhered to the paper tube by the pickup glue. The paper towel roll according to claim 7, wherein the length of the tail portion is 10 mm or more and 500 mm or less.