Manufacturing method for paper towel rolls

Abstract

To provide a method for manufacturing paper towel rolls that, even when the base paper for paper towel rolls is manufactured using a TAD paper machine, has a low basis weight, less contamination during the papermaking process, resulting in high productivity, and produces less paper dust when used as paper towel sheets. [Solution] Paper with a basis weight of 16 g / m² produced using a TAD paper machine. 2 More than 27g / m 2 A method for manufacturing a paper towel roll, comprising applying an embossed pattern to the following base paper and laminating it into 2-ply or 3-ply paper towel sheets, and winding the resulting paper towel roll into a roll, characterized in that, in the papermaking process using a TAD paper machine, the amount of wet pulp added is 50% by mass or more and 100% by mass or less of the pulp used as raw material, and the zeta potential of the pulp slurry after the addition of the wet paper strength agent is -30mV or more and -2mV or less.

Description

Technical Field

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

Background Art

[0002] The length of paper towels has been increasing. In addition to the increased length, high-quality products are also required to have high quality. Among high-quality products, paper towel sheets obtained by the so-called TAD (Through Air Dryer, also referred to as Through Air Drying) papermaking technology using through-air drying are thick, have a soft texture, and are excellent in water absorption.

[0003] As a technology related to papermaking technology using through-air drying, Patent Document 1 discloses a crepe-free through-air dried tissue sheet having protrusions with a height of about 0.012 millimeters (0.005 inches) or more, about 10 to about 150 protrusions per 6.45 square centimeters (1 square inch), an elongation rate in the machine transverse direction of about 9 percent or more, and a basis weight of about 10 to 70 grams per square meter.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] Paper towels produced using TAD papermaking technology have an uneven surface and are bulky, resulting in fewer interfiber bonds and lower strength. While increasing the pulp beating process can increase strength, this also increases the amount of fine fibers. In TAD papermaking machines, which dry the paper towels on an uneven fabric, this lowers the first-pass retention (FPR: yield of the pulp (mainly fibers), also known as the primary yield rate). As a result, fine fibers and chemicals fixed to them circulate throughout the papermaking process, leading to increased soiling. Furthermore, the increased amount of fine fibers can lead to more paper dust being produced when the paper towels are used. Of course, increasing the basis weight improves FRP (Fiber Retention Rate) and reduces contamination during the papermaking process and paper dust during use as a paper towel, but it also increases costs. Thus, it is difficult to produce paper towels using a TAD (Telescopic Adaptive) paper machine that are less contaminated during the papermaking process and produce less paper dust during use, without increasing the basis weight.

[0006] Therefore, the present invention aims to provide a method for manufacturing paper towel rolls that, even when the base paper for paper towel rolls is manufactured using a TAD paper machine, does not have a high basis weight (and thus does not incur high basis weight costs), has low contamination during the papermaking process, resulting in good productivity and less paper dust when used as paper towel sheets. [Means for solving the problem]

[0007] The inventors of the present invention conducted diligent research to achieve the above-mentioned objectives and found that the problem could be solved by keeping the basis weight of the base paper, the mixing ratio of wet pulp in the papermaking process, and the zeta potential of the pulp slurry after the addition of the wet paper strength agent all within predetermined ranges, thus completing the present invention. In other words, the present invention is as follows.

[0008] (1) Paper produced using a TAD paper machine, with a basis weight of 16 g / m². 2 More than 27g / m 2 A method for manufacturing a paper towel roll, in which a paper towel sheet, which has been laminated in 2-ply or 3-ply layers with an embossed pattern applied to the following base paper, is wound into a roll shape, In the papermaking process using the TAD paper machine, the amount of wet pulp added is 50% by mass or more and 100% by mass or less of the pulp used as raw material, and the zeta potential of the pulp slurry after the addition of the wet paper strength agent is -30mV or more and -2mV or less. This is a method for manufacturing paper towel rolls characterized by the following: (2) The manufacturing method according to (1), wherein the first pass retention in the papermaking process using the TAD paper machine is 69% or more and 95% or less. (3) The manufacturing method according to (1), wherein in the papermaking process using the TAD paper machine, the papermaking speed of the Yankee dryer is 700 m / min or more and 1800 m / min or less. (4) The water absorption capacity per unit area of ​​the aforementioned paper towel sheet is 240 g / m². 2 More than 610g / m 2 The manufacturing method is as follows: (1) (5) The specific volume of the aforementioned paper towel sheet is 7 cm³. 3 / g or more 23cm 3 The manufacturing method described in (1) is less than or equal to / g. (6) The manufacturing method described in (1) wherein the paper thickness of the two-ply paper towel sheet is 0.35 mm or more and 0.80 mm or less. (7) The manufacturing method according to (1), wherein the paper towel sheet has an uneven pattern derived from a papermaking process that is different from the embossed pattern. [Effects of the Invention]

[0009] According to the present invention, even when the base paper for paper towel rolls is manufactured using a TAD paper machine, it is possible to provide a method for manufacturing paper towel rolls that has a low basis weight, low contamination during the papermaking process, resulting in high productivity and less paper dust when used as paper towel sheets. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view of the paper towel roll packaging according to this embodiment. [Figure 2] This is a perspective view of a paper towel roll according to this embodiment. [Figure 3] This figure shows an example of an embossed pattern in a paper towel roll according to this embodiment. [Figure 4] This figure shows the height profile on the XY plane as measured by a microscope, indicated by varying shades of gray. [Figure 5] This figure shows the height profile on the XY plane as measured by a microscope. [Figure 6] This diagram shows how to determine the depth of an embossed pattern. [Figure 7] This figure shows a method for measuring the water absorption capacity of a paper towel sheet according to this embodiment. [Figure 8] This figure shows a part of the papermaking process for paper towel sheets according to this embodiment. [Modes for carrying out the invention]

[0011] 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.

[0012] Furthermore, in this specification, terms marked with "abbreviated" indicate the meaning of the term without the "abbreviated" designation, within the scope of common technical knowledge for those skilled in the art, and shall also include the meaning of the term without the "abbreviated" designation.

[0013] The method for manufacturing a paper towel roll according to an embodiment of the present invention is a method for manufacturing a paper towel roll 10 in which a paper towel sheet 10x, which is made by applying an embossed pattern to a base paper produced using a TAD paper machine and laminating it in 2-ply or 3-ply form, is wound into a roll shape. The following provides a detailed explanation of each process and the products manufactured.

[0014] <Paper towel roll base paper> The base paper for paper towel rolls according to the embodiment of the present invention can be manufactured by a general TAD papermaking method. Specifically, when using dry pulp (sheets) or wet pulp (sheets), the papermaking raw material (pulp) is dissociated with water at a predetermined concentration in a pulper (tank) to form a pulp slurry. When using slush pulp, a pulper is not required. Next, in a process (tank) called a chest or seed box, other papermaking chemicals are added as appropriate to form the pulp. This pulp is sent to a stock inlet (headbox), and the pulp is ejected from the stock inlet onto a wire. The pulp on the wire is dewatered using a dewatering roll to form a wet paper web. This wet paper web is transported to the dryer section by fabric or the like for drying. In the embodiment of the present invention, since a TAD paper machine is used in the papermaking process, a TAD is used in the dryer section. The web that has passed through the dryer section is wound up to become the base paper for paper towel rolls. Alternatively, it may be slit in a winder to adjust the width or made into small rolls (a roll with a shorter length). Calendering may also be performed. The base paper for paper towel rolls is given an embossed pattern and laminated into 2-ply or 3-ply sheets to form paper towel sheets 10x. These sheets are then wound onto a paper core 20 to a predetermined length, cut to a predetermined width, and become paper towel rolls 10. The paper towel rolls 10 are then film-wrapped to form the final product, a paper towel roll package 1. In the process of processing the base paper for paper towel rolls into the final product, the speed at which the base paper is unwound is slower than the speed at which it is wound onto the paper core 20 (also called the draw speed), and the paper is wound in a taut (stretched) state, so the basis weight changes (the basis weight after processing is often lower than the basis weight of the base paper).

[0015] (Wet pulp content) In this embodiment, wet pulp refers to the wet pulp (sheet) and slush pulp described above, and the amount of wet pulp (oven-dry mass) in the pulp used as a raw material is 50% by mass or more and 100% by mass or less. Here, wet pulp refers to pulp with a solid content of 60% by mass or less, preferably 1% by mass or more and 50% by mass or less, more preferably 2% by mass or more and 20% by mass or less, and even more preferably 3% by mass or more and 10% by mass or less. The solid content of dry pulp (sheet) is approximately 90% by mass. The lower limit of the above range for the amount of wet pulp is preferably 65% ​​by mass or more, and more preferably 80% by mass or more. If the amount of wet pulp is less than 50% by mass, the strength of the paper towel sheet 10x will be low, and as a result, the amount of paper dust will increase due to increased beating. Paper towel sheets 10x manufactured with wet pulp are easier to strengthen compared to those manufactured with only dry pulp, allowing for reduced beating and less generation of fine fibers. This contributes to reducing contamination during the papermaking process and reducing paper dust when using paper towel sheets 10x.

[0016] Furthermore, bleached softwood kraft pulp (NBKP) and bleached hardwood kraft pulp (LBKP) can be used as raw materials. The preferred blending ratio is NBKP:LBKP = 40-90% by mass:60-10% by mass, more preferably NBKP:LBKP = 50-80% by mass:50-20% by mass, and even more preferably NBKP:LBKP = 60-70% by mass:40-30% by mass. If the NBKP blending ratio exceeds 90% by mass, or the LBKP blending ratio is less than 10% by mass, the cost will be high and undesirable. Also, if the NBKP blending ratio is less than 40% by mass, or the LBKP blending ratio exceeds 60% by mass, the strength will be low, and if the beating is increased to compensate for the low strength, the amount of paper dust may increase when used as a 10x paper towel sheet.

[0017] (Wet paper strengthening agent) The wet strength agent is not particularly limited, but polyamide polyamine epichlorohydrin-based agents can be used, for example, polyamide epichlorohydrin (PAE) can be used. A dry strength agent may also be used in combination, and a polyacrylamide-based dry strength agent can be used. Since the wet strength agent is cationic (cation-rich), it is preferable that the dry strength agent is anionic (anion-rich). When the dry strength agent is anionic (anion-rich), the fixation of both the wet and dry strength agents to the fibers is improved. The wet strength agent is preferably added in a step before the seed box or fan pump (a pump that supplies pulp slurry to the headbox; generally, the pulp slurry and white water are mixed before being supplied to the headbox) from the pulper (often not used when slush pulp is used), and it is preferable that the pulp slurry concentration is preferably 1.5% by mass or more and 5.0% by mass or less, more preferably 2.0% by mass or more and 4.5% by mass or less, and even more preferably 2.5% by mass or more and 4.0% by mass or less when added. Furthermore, to strengthen the fixation of the wet strength agent and the dry strength agent with the pulp fibers, it is preferable to add them in the order of wet strength agent followed by dry strength agent.

[0018] (Zeta potential of pulp slurry) In this embodiment, the zeta potential of the pulp slurry after the addition of the wet-strength agent is -30mV or more and -2mV or less. The zeta potential of the pulp slurry after the addition of the wet-strength agent refers to the zeta potential of the pulp slurry at the site where the wet-strength agent is added. The zeta potential of the pulp slurry is measured using a zeta potential meter SZP-10 (manufactured by Voith Turbo Co., Ltd.). The zeta potential of the pulp fiber surface is measured using the flow potential method with the pulp slurry as is after the addition of the wetting force agent. A larger negative value indicates stronger anionicity, while a smaller negative value indicates weaker anionicity. A positive value indicates that the material is cationized (positively converted). If the zeta potential of the pulp slurry after adding the wet-strength agent exceeds -2mV (becomes positive), it indicates that too much wet-strength agent has been added, leading to contamination of the papermaking process by wet-strength agent that does not adhere to the fibers. On the other hand, if the zeta potential of the pulp slurry after adding the wet-strength agent is less than -30mV (becomes negative), it indicates that too little wet-strength agent has been added, resulting in weak adhesion of fine fibers to the paper, and a large amount of paper dust when used as a 10x paper towel sheet. The lower limit of the zeta potential of the pulp slurry after the addition of the wet-strength agent is preferably -23mV or higher, more preferably -13mV or higher. The upper limit of the zeta potential of the pulp slurry after the addition of the wet-strength agent is preferably -4mV or lower, more preferably -5mV or lower. The zeta potential can be adjusted by the amount of clean water used in the papermaking system (mixing process, papermaking process). It can also be adjusted by adding known papermaking chemicals such as coagulants, fixatives, and aluminum sulfate.

[0019] (First Pass Retention) The first-pass retention (FPR) when ejecting the paper pulp from the inlet onto the wire is preferably between 69% and 95%. First-pass retention is the percentage of the raw material in the pulp that accumulates on the wire. The formula for calculating it is: First-pass retention = {1 - (Concentration of pulp in the white water dewatered by the wire (mass %)) / (Concentration of pulp in the inlet (mass %))} × 100. For example, if the stock inlet pulp concentration (the total concentration of papermaking raw materials (pulp) and other solid papermaking chemicals in the pulp is 0.8% by mass) and the pulp concentration in the white water dewatered by the wire is 0.3% by mass, then the FPR = (0.8% - 0.3%) / 0.8% × 100 = {1 - (0.3% / 0.8%)} × 100 = 63%. In other words, 63% of the raw materials become paper, and 37% return to the raw materials without becoming paper. When the FPR is less than 69%, the fiber yield is low and the papermaking process gets dirty. On the other hand, when the FPR exceeds 95%, the basis weight is too high or the paper-making speed is too low, resulting in inferior productivity. The lower limit of the FPR is more preferably 74% or more, still more preferably 79% or more, and the upper limit of the FPR is more preferably 93% or less, still more preferably 92% or less.

[0020] (Paper-making speed) In addition, since the method for manufacturing the paper towel roll 1 of the present invention uses a TAD paper machine, as shown in FIG. 8, a TAD dryer 35 is used for drying the paper web 30b, but in the same process, it is preferable to use a Yankee dryer 36 for auxiliary drying of the paper web 30c. At this time, it is preferable that the paper-making speed of the Yankee dryer 36 is 700 m / min or more and 1800 m / min or less. If the paper-making speed is less than 700 m / min, the basis weight is too high or the paper-making speed is too low, resulting in inferior productivity. If it exceeds 1800 m / min, the fiber yield may be low and the papermaking process may get dirty. The lower limit of the paper-making speed is more preferably 900 m / min or more, still more preferably 1100 m / min or more. The upper limit of the paper-making speed is more preferably 1500 m / min or less, still more preferably 1300 m / min or less. Details of a part of the papermaking process of the paper towel sheet 10x of the present embodiment shown in FIG. 8 will be described later.

[0021] (Basis weight) The basis weight of the base paper for the paper towel roll according to the present embodiment is 16 g / m 2 or more and 27 g / m 2 or less. If the basis weight is less than 16 g / m 2 , the FPR becomes low and the papermaking process is likely to get dirty. Also, since the strength becomes low, it is necessary to strengthen the beating, and as a result, the amount of fine fibers increases and the amount of paper dust when used as the paper towel sheet 10x increases. Further, if the basis weight exceeds 27 g / m 2 , the cost is inferior. The lower limit of the above range of the basis weight is preferably 19 g / m 2 or more, more preferably 21 g / m 2That concludes the explanation. The upper limit of the above range for basis weight is preferably 25 g / m². 2 The following is more preferable: 23 g / m² 2 The basis weight can be measured according to JIS P 8124.

[0022] (DMDT and DCDT) The dry machine direction tensile strength (DMDT) of the paper towel roll base paper (1 ply) according to JIS P 8113 is preferably 1100 cN / 75 mm or more at the lower limit, more preferably 1400 cN / 75 mm or more, and even more preferably 1500 cN / 75 mm or more. The upper limit is preferably 2000 cN / 75 mm or less, more preferably 1800 cN / 75 mm or less, and even more preferably 1700 cN / 75 mm or less.

[0023] Furthermore, the dry cross-direction tensile strength (DCDT) of the paper towel roll base paper (1 ply), based on JIS P 8113, is preferably 1000 cN / 75 mm or more at the lower limit, more preferably 1300 cN / 75 mm or more, and even more preferably 1400 cN / 75 mm or more. The upper limit is preferably 1900 cN / 75 mm or less, more preferably 1700 cN / 75 mm or less, and even more preferably 1600 cN / 75 mm or less. In this case, the cross-direction refers to the CD direction (roll width direction).

[0024] If DMDT or DCDT is below the lower limit mentioned above, the basis weight and FPR will be low, leading to contamination during the papermaking process. On the other hand, if DMDT or DCDT exceeds the upper limit mentioned above, the cost per basis weight will be lower. Note that DMDT and DCDT of base paper for paper towel rolls are measured in accordance with JIS P 8113.

[0025] <Paper towel roll> Figure 2 is a perspective view of a paper towel roll 10 manufactured by the paper towel roll manufacturing method according to this embodiment.

[0026] As shown in Figure 2, the paper towel roll 10 according to this embodiment is a paper towel roll 10 formed by winding a paper towel sheet 10x around a paper tube 20 (hereinafter also referred to as a core) and winding it into a roll shape. Preferably, the paper towel sheet 10x has perforations in the roll width direction at approximately equal intervals in the roll winding direction (not shown).

[0027] As shown in Figure 2, the surface of the paper towel sheet 10x facing outwards from the roll is referred to as surface 10a (the surface of the paper towel sheet 10x), and the surface facing towards the center of the roll is referred to as back surface 10b (the back surface of the paper towel sheet 10x). The edge of the paper towel sheet 10x is referred to as the outermost edge 10e of the paper towel roll 10.

[0028] Uses of paper towel rolls 10 include, for example, rolls of kitchen paper (sometimes called kitchen towels, cooking paper, etc.) used in home kitchens and restaurant kitchens for wiping up moisture or oil and removing dirt, as well as rolls of other sanitary paper.

[0029] (Roll length and roll diameter) The roll length of the paper towel roll 10 is preferably 18m or more at the lower limit, more preferably 20m or more, and even more preferably 24m or more. The upper limit is preferably 45m or less, more preferably 40m or less, and even more preferably 35m or less. If the roll length exceeds the upper limit mentioned above, the basis weight must be lowered to maintain a constant roll diameter DR, resulting in a lower FPR and potentially contaminating the papermaking process. Additionally, the reduced strength necessitates increased beating, resulting in more paper dust when used as a paper towel sheet. Furthermore, if the roll length is less than the lower limit mentioned above, the paper thickness and basis weight must be increased to maintain a constant roll diameter DR, which may result in lower basis weight costs.

[0030] The roll length is preferably measured as follows: First, measure the length of 10 sheets of paper towels 10x between the perforations of the paper towel roll 10. Then, measure the number of sheets in the paper towel roll 10, 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 the paper towel roll 10 does not have perforations, it is preferable to measure the roll length by hand.

[0031] The winding diameter DR of the paper towel roll 10 according to this embodiment is preferably 127 mm or more at the lower limit, more preferably 135 mm or more, and even more preferably 140 mm or more. The upper limit is preferably 175 mm or less, more preferably 165 mm or less, and even more preferably 157 mm or less. On the other hand, if the winding diameter DR exceeds the upper limit mentioned above, the basis weight of the paper towel sheet 10x will increase, resulting in lower costs. Also, if the winding diameter DR is less than the lower limit mentioned above, the FRP will be lower in order to lower the basis weight, which may contaminate the papermaking process. Furthermore, the strength will be lower, requiring stronger beating, which will result in more paper dust when used as a paper towel sheet.

[0032] The roll diameter DR is measured using, for example, a diameter rule manufactured by Muratec KDS Corporation. It is preferable to measure three paper towel rolls 10 and average the results.

[0033] (Roll width and roll mass) The roll width of the paper towel roll 10 is preferably 150 mm or more at the lower limit, more preferably 200 mm or more, and even more preferably 250 mm or more. The upper limit is preferably 380 mm or less, more preferably 340 mm or less, and even more preferably 300 mm or less. If the roll width exceeds the upper limit mentioned above, the amount of water absorbed will be excessively large, making it difficult to use as a paper towel sheet. On the other hand, if the roll width is below the lower limit mentioned above, the amount of water absorbed will be small, making it difficult to use as a paper towel sheet.

[0034] The roll mass of the paper towel roll 10 is preferably 200g or more at the lower limit, more preferably 240g or more, and even more preferably 260g or more. The upper limit is preferably 550g or less, more preferably 490g or less, and even more preferably 450g or less. On the other hand, if the roll mass is less than the lower limit mentioned above, the basis weight will be low, resulting in low FPR, which may lead to contamination during the papermaking process. Also, if the roll mass exceeds the upper limit mentioned above, the basis weight will be high, which may result in lower costs.

[0035] The roll mass shall be the mass per 280 mm roll width, excluding the core (paper tube 20) of the paper towel roll 10. If the roll width is not 280 mm, the mass shall be converted to a 280 mm mass using proportional calculation.

[0036] (Roll density) The roll density of the paper towel roll 10 according to this embodiment is preferably 0.04 g / cm³ at the lower limit. 3 The above is more accurate, and more preferably 0.05 g / cm³ 3 The above is preferable, and more preferably 0.06 g / cm³ 3 That is all. The upper limit is preferably 0.13 g / cm³. 3 The following, and more preferably 0.10 g / cm³ 3 The following, and more preferably 0.09 g / cm³ 3The following applies: On the other hand, if the roll density exceeds the upper limit mentioned above, the basis weight will be high and the cost will be lower. Also, if the roll density is below the lower limit mentioned above, the basis weight will be low, resulting in a lower FRP (Fiber Reinforced Plastic) and potentially leading to contamination during the papermaking process.

[0037] Roll density is expressed as (roll mass) ÷ (roll volume). Roll mass is the mass of 10 paper towel rolls 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 20)] × roll width (converted to per 280 mm). For example, if the roll mass (excluding core) per 280 mm roll width is 382 g, the winding diameter DR is 150 mm, and the paper core outer diameter DI is 39 mm, then roll density = 382 g ÷ [{3.14 × (150 mm ÷ 2 ÷ 10) 2 -3.14 × (39mm ÷ 2 ÷ 10) 2} × (280 mm ÷ 10) = 0.08 g / cm 3 This is the result.

[0038] (winding density) The winding density of the paper towel roll 10 according to this embodiment is preferably 0.20 m / cm at the lower limit. 2 The above, and more preferably 0.24 m / cm 2 The above, and more preferably 0.30 m / cm 2 That's all. The upper limit is preferably 0.56 m / cm. 2 The following, and more preferably 0.50 m / cm 2 The following, and more preferably 0.45 m / cm 2 The following applies. On the other hand, if the winding density is below the lower limit mentioned above, the basis weight may be high and the cost may be lower. Also, if the winding density exceeds the upper limit mentioned above, the basis weight will be low, resulting in a lower FRP and potentially leading to contamination during the papermaking process.

[0039] 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 20)}. For example, in the case of a winding length of 27m, 2 plies, winding diameter DR 150mm, and paper core outer diameter DI 39mm, the winding density = (27m × 2) ÷ {3.14 × (150mm ÷ 2 ÷ 10)} 2 -3.14 × (39mm ÷ 2 ÷ 10) 2} = 0.33 m / cm 2 This is the result.

[0040] (Paper tube) The paper towel roll 10 preferably has a paper tube 20 at its center that is parallel to the axial direction. The paper tube 20 is a core for winding the paper towel sheets 10x around it, and may be, for example, roughly cylindrical in cross-section. The paper tube 20 is made of multiple sheets of base paper stacked together, and it is preferable that it is made of two sheets stacked together.

[0041] (Paper tube outer diameter) Furthermore, the outer diameter DI of the paper tube 20, which is the core of the paper towel roll 10, is preferably 28 mm or more at the lower limit, more preferably 33 mm or more, and even more preferably 40 mm or more. The upper limit is preferably 58 mm or less, more preferably 53 mm or less, and even more preferably 46 mm or less. On the other hand, if the outer diameter DI of the paper tube is less than the lower limit or more than the upper limit mentioned above, it may become difficult to use.

[0042] The outer diameter DI of the paper core is measured using, for example, a Diameter Rule manufactured by Muratec KDS Corporation. It is preferable to measure three paper towel rolls 10 and average the measurement results.

[0043] <Paper towel roll>

[0044] The paper towel sheet 10x according to this embodiment is 2-ply or 3-ply, and is preferably 2-ply.

[0045] (Basic weight) The basis weight per ply of the paper towel sheet 10x according to this embodiment is preferably 30 g / m² at the lower limit. 2 The above is preferable to 34 g / m². 2 The above is preferable, and more preferably 38 g / m² 2 That is all. The upper limit is preferably 56 g / m². 2 The following is more preferable: 50 g / m 2 The following is more preferably 46 g / m² 2 The following applies: If the basis weight per ply is below the lower limit mentioned above, the FRP will be low, leading to contamination during the papermaking process. Furthermore, if the beating process is increased to compensate for the reduced strength, there may be a large amount of paper dust when used as a paper towel sheet. Also, if the basis weight exceeds the upper limit mentioned above, it may be less cost-effective. Moreover, if the basis weight exceeds the upper limit, the winding diameter DR will increase in order to maintain a certain roll density. When the winding diameter DR increases, the contact area between the rolls increases, resulting in greater damage to the paper towel roll 10. In addition, more paper dust is generated when the rolls rub against each other. Basis weight can be measured according to JIS P 8124, but the basis weight per product ply refers to the basis weight measured without changing the number of plies in a 10x paper towel sheet (without peeling or adding plies).

[0046] (Water absorption amount) In this embodiment, the water absorption capacity per unit area of ​​the paper towel sheet 10x is 240 g / m². 2 More than 610g / m 2The following conditions are preferable. If the water absorption per unit area is below the lower limit mentioned above, the basis weight will be low, resulting in a low FRP, which may lead to contamination during the papermaking process. Also, if the water absorption per unit area exceeds the upper limit mentioned above, the basis weight of the paper towel sheet 10x will be high, which may be cost-ineffective. Furthermore, if the water absorption per unit area exceeds the upper limit mentioned above, the basis weight of the paper towel sheet 10x will be high, and the winding diameter DR will need to be increased to maintain a certain roll density. And when the winding diameter DR is increased, the contact area between the rolls increases, which may increase damage to the paper towel roll 10. Furthermore, the lower limit of the above range for water absorption per unit area is more preferably 290 g / m². 2 The above, and more preferably 380 g / m² 2 That concludes the explanation. The upper limit of the above range for water absorption per unit area is more preferably 550 g / m². 2 The following, and more preferably 500 g / m² 2 The following applies:

[0047] Furthermore, the water absorption per unit mass of the paper towel sheet 10x is preferably 8.0 g / g or more, more preferably 8.5 g / g or more, and even more preferably 9 g / g or more. There is no particular upper limit, but it is preferably 14 g / g or less, and more preferably 13 g / g or less. If the water absorption per unit mass is above the lower limit mentioned above, the decrease in water absorption of the paper towel sheet 10x can be prevented more effectively. On the other hand, if the water absorption per unit mass is below the lower limit mentioned above, the basis weight of the paper towel sheet 10x will increase in order to ensure water absorption, which may be costly. Also, if the water absorption per unit mass exceeds the upper limit mentioned above, the paper thickness relative to the basis weight will increase, resulting in a higher specific volume, which may lead to a lower FPR and contamination during the papermaking process.

[0048] Figure 7 shows a method for measuring the water absorption capacity of a paper towel sheet according to an embodiment.

[0049] Furthermore, when a paper towel sheet 10x is 2-ply, the water absorption capacity of each sheet is preferably measured as follows. First, a 2-ply stacked paper towel sheet 10x is taken and cut using a square template with sides of 7.6 cm to create a rectangular test piece 200 with sides of 7.6 cm. The mass of the test piece 200 before water absorption is measured using an electronic balance. The test piece 200 is then set in a holder 210 (a jig that fixes the test piece 200 at three points, and the jig is made of a metal that does not absorb moisture).

[0050] Next, fill a commercially available tray with distilled water to a depth of 2 cm and immerse the test piece 200, which is set in the holder 210, in the distilled water for 2 minutes. After 2 minutes of immersion, remove the test piece 200 together with the holder 220 from the distilled water, and as shown in Figure 7, hang the holder 210 and the test piece 200 from a rod placed in an empty water tank with the corner 200a facing upwards, close the lid of the water tank, and leave it for 5 minutes.

[0051] Next, the holder 210 and test piece 200 are removed from the water bath, the holder 210 is removed, and the mass of the test piece 200 is measured using an electronic balance. From the change in mass of the test piece 200 before and after immersion in distilled water, the amount of distilled water absorbed per unit area of ​​the test piece 200 (water g / sheet m) is determined. 2 , 1m 2 Correct. Abbreviated as g / m 2 Calculate the amount of water absorbed per unit area (water g / sheet m). 2 By dividing this by the basis weight of the product ply of 200 test pieces, the water absorption per unit area (water g / sheet m²) can be calculated. 2 ) / Basis weight (sheet g / sheet m 2 Calculate the water absorption per unit mass (g of water / g of sheet, per gram; abbreviated as g / g). Measure each sample 5 times and use the average value.

[0052] Furthermore, even if the 10x paper towel sheet is 3-ply, it is preferable to measure it as is, using the same procedure as for the 2-ply sheet. This measurement will be performed according to the JIS P 8111 method, under conditions of 23±1°C and 50±2% humidity. Distilled water will also be maintained at 23±1°C.

[0053] (Embossed pattern) The paper towel roll 10 (paper towel sheet 10x) of this embodiment can be embossed and have an embossed pattern (an embossed pattern is applied). Furthermore, the paper towel sheet 10x can be laminated after embossing. When laminating, for example, a plybond glue (adhesive) can be used to apply the glue and perform the bonding treatment. Alternatively, water may be used instead of plybond glue (adhesive).

[0054] Plybond glue can be applied to the back side of the embossed portion of the front 10a sheet of a 2-ply paper towel sheet 10x (between the front 10a sheet and the back 10b sheet of the 2-ply sheet), allowing the two sheets to be laminated. In the case of a 3-ply sheet, it is also possible to emboss the two front 10a layers and apply glue to the back side of the middle layer, or to emboss the first front 10a layer and apply glue to the back side of the front 10a layer. Of these, it is preferable to emboss the two front 10a layers and apply glue to the back side of the middle layer.

[0055] The surface 10a side of the paper towel sheet 10x may have an embossed pattern. The embossed pattern on the surface 10a side allows glue to be applied to the embossed areas, enabling lamination of two or more plies. The back side 10b side may also have an embossed pattern, but it is preferable that it does not. By not having an embossed pattern on the back side 10b, a paper towel sheet 10x (paper towel roll 10) with less paper dust can be produced. The embossed pattern is not particularly limited as long as it is a pattern commonly applied to paper towels, such as dots or lines, but a linear embossed pattern is preferred. A linear embossed pattern can more effectively suppress the generation of paper dust when the rolls rub against each other.

[0056] Figure 3 shows an example of an embossed pattern on a paper towel roll according to the embodiment.

[0057] There are no particular restrictions on the linear embossing pattern, but patterns like those shown in Figure 3 are preferred. Specifically, a pattern should include two of each of two types of figures: a roughly circular shape with another pattern inside, and a figure that is roughly symmetrical vertically and horizontally (a tilt may be provided) and includes a combination of multiple curves and figures. However, the shape of the figures is not particularly limited. For the roughly circular shape, it is preferable that the roughly circular shape is doubled.

[0058] Furthermore, regarding the dimensions of the embossed pattern, it is preferable that the rectangle E (E is not part of the embossed pattern) surrounding the embossed pattern is a square with sides of 2 cm to 25 cm. The lower limit of the above range for rectangle E is more preferably a square with sides of 5 cm or more, and even more preferably a square with sides of 8 cm or more. The upper limit of the above range for rectangle E is more preferably a square with sides of 20 cm or less, and even more preferably a square with sides of 15 cm or less. For this rectangle E, it is preferable that the vertical direction is parallel to the winding direction of the paper towel roll 10 and the horizontal direction is parallel to the width direction of the paper towel roll 10, but it may be tilted (in this case, rectangle E may be a rhombus instead of a square). By using such a pattern, the water absorption capacity of the paper towel sheet 10x, which has high water absorption capacity, can be further improved. In addition, by using a linear embossed pattern, the generation of paper dust when the rolls rub against each other can be suppressed even more effectively.

[0059] In this case, for linear embossed patterns, where the thickness is 0.1 mm or more and the length is 5 mm or more, the total length when the lengths of the embossed areas are added together is preferably 50 cm / 100 cm at the lower limit. 2 The above, more preferably 80cm / 100cm 2 The above, and more preferably 110cm / 100cm 2That's all. The upper limit is preferably 550cm / 100cm. 2 The following, and more preferably 410cm / 100cm 2 The following, and more preferably 300cm / 100cm 2 The following applies: The total length is measured by adding up the lengths of the embossed areas within a rectangle E that contains the entirety of one embossed pattern, as shown in Figure 3, where the thickness is between 0.1 and 4 mm and the length is 5 mm or more. The total length is then measured at 100 cm. 2 Calculate the total length of the area. The size of one side of this rectangle E can be changed as appropriate depending on the size of the embossed pattern. Note that if an embossed pattern adjacent to an embossed pattern contained within a rectangle that contains all of the embossed patterns, the length of that adjacent embossed pattern should also be measured and included in the total length.

[0060] Furthermore, if the size of one side of rectangle E cannot be clearly determined by the embossing pattern, the size of rectangle E is set to 10 × 10 cm, and the total length of the embossed area within this rectangle E is measured. By keeping the total length within the range described above, the water absorption capacity of the highly absorbent paper towel sheet 10x, as in this embodiment, can be further improved. In addition, damage caused by friction between rolls can be more effectively suppressed. The total length is determined by the method described above, but it may also be measured using a general microscope. Furthermore, with respect to the area of ​​the paper towel sheet 10x, the ratio of the area occupied by linear embossing patterns with a thickness of 0.1 mm to 4 mm and a length of 5 mm or more is preferably 4% or more at the lower limit, more preferably 6% or more, and even more preferably 8% or more. The upper limit is preferably 35% or less, more preferably 25% or less, and even more preferably 15% or less. The above area ratio is calculated by taking the inside of a rectangle E that contains the entirety of one embossed pattern as shown in Figure 3, and measuring the total length of the embossed areas that are 0.1 mm to 4 mm thick and 5 mm or longer, and calculating the total length (mm) × width (mm) as the area of ​​the embossed area. The area of ​​one sheet of paper towels 10x is calculated as (sheet length × sheet width) × 100 (%). If it is difficult to determine the embossed area ratio, the area ratio of the raised portion of the embossing roll used for embossing can be considered as the area of ​​one sheet of paper towel sheets 10x.

[0061] In the embossed pattern, the lower limit of the embossing depth is preferably 0.06 mm or more, more preferably 0.10 mm or more, and even more preferably 0.14 mm or more. The upper limit is preferably 1.05 mm or less, more preferably 0.55 mm or less, and even more preferably 0.35 mm or less.

[0062] The depth of the embossing can be measured, for example, using a microscope. The KEYENCE VR-3100 One-Shot 3D Measurement Macroscope can be used as the microscope. The VR-H1A software can be used for observing, measuring, and analyzing the microscope images. The measurement conditions are 25x magnification and a field of view of 12mm x 9mm. The magnification and field of view may be adjusted as needed depending on the desired embossing size.

[0063] Figure 4 shows the height profile on the XY plane as measured by a microscope, using shades of gray. Figure 5 shows the height profile on the XY plane as measured by a microscope, using a graph. Figure 6 shows how to determine the depth of the embossing pattern.

[0064] Figure 4 shows the height profile on the XY plane obtained by a microscope, with the height of the 10x surface of the paper towel sheet represented by shades of gray. Linear areas in Figure 4 with different shades from the surrounding areas indicate individual embossing. The depth of the embossing is determined by measuring the height difference of the embossing using the microscope described above.

[0065] It is preferable to perform the measurement on the surface 10a side of the paper towel sheet 10x. Furthermore, during measurement, remove three turns of the paper towel sheet 10x from the paper towel roll 10, and use the fourth turn of the paper towel sheet 10x, measuring in its original state without changing the ply count. Also, if there are perforations, avoid them during measurement.

[0066] First, draw line segment AB as shown in Figure 4 to obtain the height profile shown in Figure 5. Note that line segment AB should be drawn across the embossing. Line segment AB should be drawn in the direction of the roll width (CD direction) of the paper towel sheet 10x, but if the spacing between embossings is narrow, for example, 2 mm or less, and the height of the raised part below becomes low, the line segment may be drawn diagonally or in the direction of the roll winding R.

[0067] The height profile is the (measured) cross-sectional curve S, which represents the surface irregularities of the actual paper towel sheet 10x sample. However, the (measured) cross-sectional curve S also contains noise (steep peaks caused by fiber clumps on the surface of the paper towel sheet 10x, fibers extending in a whisker-like manner, or areas without fibers). When calculating the height difference of the irregularities, it is necessary to remove such noise peaks.

[0068] Therefore, the (measured) cross-sectional curve S in Figure 5 is smoothed with a weighted average radio button filter size of ±12 to obtain the cross-sectional curve W in Figure 6. Note that smoothing using the weighted average radio button filter can be obtained automatically using the analysis software mentioned above. Then, in the graph shown in Figure 6, the average of the maximum values ​​on the vertical axis of the convex part H1 and the convex part H2 adjacent to convex part H1 is calculated, and the minimum value on the vertical axis at the concave part D1 sandwiched between convex parts H1 and H2 is found. The value obtained by subtracting the minimum value from the average of the maximum values ​​obtained in this way is taken as the provisional embossing depth.

[0069] Furthermore, as shown in Figure 6, the same measurement is performed at two consecutive locations on the cross-sectional curve (the recess D1 and the recess D2 sandwiched between the protrusions H3 and H4) (two measurement results are obtained at this point). Subsequently, the same measurement is performed at each position where the paper towel roll 10 is rotated 90 degrees three times in the roll winding direction of the paper towel sheet 10x (a total of four measurement positions in the roll winding direction). Finally, the average value of the total of eight locations (2 x 4) is adopted as the embossing depth.

[0070] In this embodiment, it is preferable that the paper towel sheet 10x has a pattern of irregularities derived from the papermaking process, which is different from the embossed pattern. Having a pattern of irregularities derived from the papermaking process, which is different from the embossed pattern, makes it possible to make a paper towel sheet 10x with better water absorption. In addition, a paper towel roll 10 wound with such a paper towel sheet 10x becomes less prone to crushing. The method of applying the pattern of irregularities derived from the papermaking process will be described later.

[0071] Furthermore, due to the uneven pattern resulting from the papermaking process, variations in the height of the convex parts on either side of the concave area are observed. Therefore, if the difference in the vertical axis values ​​between the convex parts flanking the concave area (for example, convex parts H3 and H4 flanking concave area D2) is 0.2 mm or more, measurements should be taken at locations that avoid that area.

[0072] The back surface 10b of the paper towel sheet 10x is not particularly limited in terms of whether or not it has an embossed pattern, as long as it has a pattern of irregularities derived from the papermaking process that is different from the embossed pattern. It may have nested embossing or pin-to-pin embossing, or it may not have embossing at all, but it is preferably nested embossing or no embossing, and more preferably no embossing.

[0073] Conventional paper towels ensure water absorption through pin-to-pin or nested methods. However, when using thick paper, as mentioned earlier, embossing can crush the paper, reducing water absorption. Therefore, in this embodiment, it is preferable that the surface 10a of the paper towel sheet 10x has linear embossing, and the back surface 10b has no embossing.

[0074] (Sheet length) The sheet length between perforations (length of paper towel sheets 10x 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.

[0075] (specific volume) The specific volume of a 10x paper towel sheet is 7 cm³. 3 / g or more 23cm 3 It is preferable that the specific volume is less than or equal to / g. The lower limit of the above range for the specific volume of the paper towel sheet 10x is more preferably 9cm³. 3 / g or more, and more preferably 13cm 3 It is 19 cm² or more. The upper limit of the specific volume of the paper towel sheet 10x is more preferably 19 cm³. 3 / g or less, and more preferably 15cm 3It is less than / g. On the other hand, if the specific volume is below the lower limit mentioned above, the basis weight of the 10x paper towel sheet will be high, which may result in lower costs. Also, if the specific volume exceeds the upper limit mentioned above, the basis weight will be low, the FPR will be low, which may lead to contamination in the papermaking process. In addition, the strength will be lower, requiring stronger beating, which may result in more paper dust when used as a paper towel sheet. Specific volume is calculated by dividing the paper thickness per ply of a 10x paper towel sheet by the basis weight per ply, and then determining the volume per gram (cm³). 3 It is represented as follows.

[0076] (paper thickness) Furthermore, the paper thickness of the product ply of the paper towel sheet 10x is preferably 0.35 mm or more and 0.80 mm or less. The lower limit of the above range for the paper thickness of the product ply is more preferably 0.40 mm or more, and even more preferably 0.45 mm or more. The upper limit of the above range for the paper thickness per product ply is more preferably 0.75 mm or less, and even more preferably 0.70 mm or less. On the other hand, if the paper thickness per ply is below the lower limit mentioned above, the basis weight will be low, resulting in a low FRP (Fiber Reinforced Plastic) ratio, which may lead to contamination during the papermaking process. Furthermore, the lower strength may necessitate increased beating, potentially resulting in more paper dust when used as a paper towel sheet. Additionally, if the specific volume exceeds the upper limit mentioned above, the basis weight of the 10x paper towel sheet will be high, potentially making it less cost-effective.

[0077] Paper thickness 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 10 sheets of 10x paper towels (5 sets for 2-ply paper, 3 sets for 3-ply paper, and the value is proportionally calculated to equal 10 sets). The measurement is repeated 10 times at different locations, the measurement results are averaged, and the value is converted to the amount per ply of the product using proportional calculation.

[0078] <Paper towel roll packaging> As described above, the paper towel roll packaging 1 consists of three rolls of paper towel sheets 10x wound into a roll shape, which are then film-wrapped in a film with the rolls arranged adjacent to each other so that their axial directions are parallel to each other.

[0079] The paper towel roll packaging 1 can be manufactured, for example, in the following order: (1) papermaking and creping, (2) embossing, (3) roll winding, and (4) film packaging of the three rolls. In the paper towel sheet 10x manufacturing (papermaking) process, TAD papermaking technology is used.

[0080] Figure 8 shows a part of the papermaking process for paper towel sheets according to the embodiment.

[0081] In this case, it is preferable that, during the papermaking process, a pattern of irregularities originating from the papermaking process (fabric), different from the embossing pattern described above, is applied to the paper towel sheet 10x. Having this pattern of irregularities further increases the water absorption capacity of the paper towel sheet 10x.

[0082] Furthermore, "originating from the papermaking process" means that in the papermaking process of the paper towel sheet 10x, a pattern of bumps and dips is applied between the headbox 31 of the papermaking machine and the outlet of the Yankee dryer 36. Specifically, in a part of the papermaking process shown in Figure 8, paper web 30a, which is in the state of pulp slurry, is sprayed (supplied) from the headbox 31 between the first fabric (forming fabric) 32 and the second fabric (bumpy fabric) 33, and is drawn onto the second fabric (bumpy fabric) 33 by the forming roll 34, forming paper web 30b, which is in the state of wet paper. Next, the paper web 30b is dried together with the second fabric (textured fabric) 33 in the TAD dryer 35, and as a result, the texture is formed on the dried sheet of paper web 30c. In Figure 8, the TAD dryer 35 is shown with two units, but one unit may be used. Also, a Yankee hood is shown on the Yankee dryer 36, but the hood is not required. Furthermore, a crepe may be applied in the Yankee dryer 36.

[0083] Furthermore, the pattern of the unevenness can be changed as needed by altering the fabric pattern (fine pattern, coarse pattern). Changing the pattern of the unevenness will change the specific volume (paper thickness), but it is preferable to select a pattern such that the specific volume (paper thickness) of the base paper falls within the numerical range described above.

[0084] Furthermore, (4) in film packaging, the packaging form of the packaging film 2 may be the caramel packaging shown in Figure 1. Alternatively, the packaging form may be gusset packaging (not shown).

[0085] In the case of caramel packaging, there are no particular restrictions on the equipment or process used, as long as it is a known packaging device or process capable of performing caramel packaging. For example, three paper towel rolls 10 are placed on a sheet-like packaging film 2, and the packaging film 2 is wrapped around the circumferential surface of the paper towel rolls 10 to form a tube, or three paper towel rolls 10 are inserted coaxially with the tube-shaped packaging film 2 from one end of a pre-formed tube-shaped packaging film 2. Then, of the packaging film 2 that protrudes from both ends of the three paper towel rolls 10, it is preferable to fold two opposing flap-like edges toward each other, then similarly fold two other opposing flap-like edges toward each other, and then seal these folded portions by heat fusion or the like (heat sealing). Alternatively, from below the set sheet-like film 2, three paper towel rolls 10, arranged so that their axial directions are parallel to each other, are raised up to the sheet surface (bottom side) of the film 2. In this state, the film 2 is wrapped around the circumferential surface of the paper towel rolls 10 to form a tube, and the overlapping portions of both ends of the film 2 on the circumferential surface of the paper towel rolls 10 are heat-sealed (not shown) along the long side direction of the paper core of the paper towel rolls 10. In other words, it is preferable that the packaging film 2 has heat-sealing properties so that it can be heat-sealed.

[0086] When the packaging form is gusset packaging, there are no particular restrictions on the equipment or process used, as long as it is a known packaging device or process capable of performing gusset packaging. For example, it is preferable to gusset-package three paper towel rolls 10 with a packaging film 2 made of polyethylene so as to conform to the surface shape of the roll product, thereby producing a 3-roll package (paper towel roll package 1). [Examples]

[0087] The present invention will be described in more detail by the following examples and comparative examples, but the present invention is not limited in any way by the following examples.

[0088] (1) Papermaking and creping (all using a TAD paper machine), (2) Embossing, and (3) Roll winding were performed to produce the base paper and paper towel rolls for Examples 1 to 12 and Comparative Examples 1 to 5. For all the base paper and paper towel rolls of the Examples and Comparative Examples, each parameter was measured in accordance with the method described above, and the following evaluations were performed in accordance with the method described above. The embossing was applied only to the front side of the paper towel sheets. Furthermore, all the paper towels of the Examples and Comparative Examples were manufactured for use as kitchen towels.

[0089] (Resistance to contamination during the papermaking process) The "reduced likelihood of contamination during the papermaking process" was evaluated on a four-point scale based on the amount of foreign matter generated during papermaking (contamination during the papermaking process leads to increased foreign matter generation). The evaluation criteria are as follows: ◎: There were significantly fewer foreign objects. ○: There were few foreign objects. △: The foreign object was not a problem. ×: There were many foreign objects.

[0090] (Cost based on basis weight) The "cost by basis weight" was evaluated by measuring the basis weight per ply of the paper towel roll base paper and rating it on a four-point scale. The evaluation criteria are as follows: ◎: Basis weight is 23g / m² 2 The results were as follows: ○: Basis weight is 23g / m² 2 Over 25g / m 2 The results were as follows: △: Basis weight is 25g / m² 2 Over 27g / m 2 The results were as follows: ×: Basis weight is 27g / m² 2 It exceeded expectations.

[0091] (Amount of paper dust when used as a paper towel sheet) Regarding the amount of paper dust, 30 monitors tested a 100cm sheet of paper towels with the same number of plies as the product. 2 The table was wiped using the product, and the user selected either "a lot of paper dust" or "a little paper dust." ◎: More than 28 monitors rated the product as having low paper dust. ○: Between 25 and 27 monitors rated the product as having low paper dust. △: Between 22 and 24 monitors rated the product as having low paper dust. ×: Fewer than 21 monitors rated the paper dust as low.

[0092] The results obtained are shown in Tables 1 and 2.

[0093] [Table 1]

[0094] [Table 2]

[0095] Based on the above, it was confirmed that the paper towel rolls of this embodiment have a low basis weight and less contamination during the papermaking process, resulting in high productivity, and that they produce paper towels with less paper dust when used as paper towel sheets. [Explanation of Symbols]

[0096] 1. Paper towel roll packaging 2 Packaging film 10 paper towel rolls 10a surface 10b back side 10e Paper towel roll outermost edge 10x Paper Towel Sheets 20 paper tube 30a, 30b, 30c Paper Web 31 Headbox 32,33 Fabric 34 Foaming Roll 35 Through Air Dryer 36 Yankee Hair Dryer 200 test specimens 200a Corner 210 holder

Claims

1. Paper produced using a TAD paper machine, with a basis weight of 16 g / m². ２ More than 27g / m ２ A method for manufacturing a paper towel roll, in which a paper towel sheet, which has been laminated in two or three plies with an embossed pattern applied to the following base paper, is wound into a roll shape, In the papermaking process using the TAD paper machine, the amount of wet pulp added is 50% by mass or more and 100% by mass or less of the pulp used as raw material, and the zeta potential of the pulp slurry after the addition of the wet paper strength agent is -30 mV or more and -2 mV or less. A method for manufacturing paper towel rolls characterized by the following.

2. The method for manufacturing a paper towel roll according to claim 1, wherein the first pass retention in the papermaking process using the TAD paper machine is 69% or more and 95% or less.

3. The method for manufacturing a paper towel roll according to claim 1, wherein in the papermaking process using the TAD paper machine, the papermaking speed of the Yankee dryer is 700 m / min or more and 1800 m / min or less.

4. The water absorption capacity per unit area of ​​the aforementioned paper towel sheet is 240 g / m². ２ 610g / m or more ２ The method for manufacturing a paper towel roll according to claim 1 is as follows:

5. The specific volume of the aforementioned paper towel sheet is 7 cm³. ３ / g or more 23cm ３ A method for manufacturing a paper towel roll according to claim 1, wherein the amount is less than or equal to / g.

6. The method for manufacturing a paper towel roll according to claim 1, wherein the paper thickness of the two-ply paper towel sheet is 0.35 mm or more and 0.80 mm or less.

7. The method for manufacturing a 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.

Images