How paper towel rolls are made

Abstract

To provide a method for producing a wrinkle-free paper towel roll with excellent decorative properties without reducing texture, water absorbency and tear resistance. [Solution] A method for manufacturing a paper towel roll involves imparting an embossed pattern to at least one ply of base paper made using a TAD papermaking machine, and then laminating the resulting paper towel sheet into two or three plies and winding it into a roll.The method is characterized in that in the papermaking process using the TAD papermaking machine, a headbox with a slurry blowing section that branches into at least two layers is used, and a drying process using a Yankee dryer is also used.

Description

[Technical Field]

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

[0002] In recent years, various types of paper towel sheets and paper towel rolls made by rolling up sheets have been developed and sold.

[0003] In such paper towel rolls, the wound paper towel sheets are becoming longer and longer, but high-quality products require not only longer lengths but also other qualities such as aesthetic appeal and water absorbency.

[0004] Among high-end products, paper towel sheets made using the so-called TAD (Through Air Drying) papermaking technology, which uses air drying, are thick, soft to the touch, and have excellent water absorbency.

[0005] Because paper towel sheets made using TAD papermaking technology have the advantages described above, many paper towel rolls sold on the market also use TAD papermaking technology in their manufacturing process.

[0006] As a prior art document relating to paper towel rolls, for example, Patent Document 1 describes a kitchen towel roll in which sheets with embossed patterns are glued together and laminated into two plies, and the resulting kitchen towel sheet is wound into a roll. The kitchen towel sheet has a concave-convex pattern derived from the papermaking process that is different from the embossed pattern, and the basis weight of the two plies is 30 g / m. 2 More than 54g / m 2 The following is a paper thickness of 1.3 mm / 10 sheets or more and 5 mm / 10 sheets or less, 2 ply, 1 m 2 The kitchen towel roll is characterized by having a water absorption per roll of 220 g to 600 g, a roll length of 14 m to 44 m, and a roll diameter of 110 mm to 189 mm.

[0007] However, because paper towel sheets made using TAD papermaking technology are bulky and uneven, they have few interfiber bonds and are therefore weak. As a result, they tend to wrinkle when wet, and wrinkles also tend to form during the drying process using a Yankee dryer and when the raw roll is wound up, resulting in a reduction in aesthetic appeal.

[0008] One way to prevent wrinkles from occurring is to increase the content of bleached softwood kraft pulp (NBKP) in the base paper. However, if the content of bleached softwood kraft pulp (NBKP) in the entire wet paper is increased, the strength of the base paper becomes too high, resulting in a stiff feel and poor texture. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Japanese Patent Publication No. 2022-116768 Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made in view of the above circumstances, and aims to provide a method for producing a wrinkle-free paper towel roll with excellent decorative properties without reducing texture, water absorbency, and tear resistance. [Means for solving the problem]

[0011] The inventors conducted extensive research and discovered a method for manufacturing a paper towel roll, in which an embossed pattern is imparted to at least one ply of base paper made using a TAD papermaking machine, and the resulting paper towel sheet is wound into a roll by laminating two or three plies. A specified headbox is used in the papermaking process. In the drying process using a Yankee dryer, the surface of the wet paper that contacts the drum surface of the Yankee dryer is defined as the "drum surface of the wet paper" and the surface opposite the "drum surface of the wet paper" is defined as the "hood surface of the wet paper." The NBKP blending ratio of the "hood surface of the wet paper" is set within a specified numerical range, and its size relative to the opposite "drum surface of the wet paper" is specified. Furthermore, the basis weight and (DMDT / DCDT) of the base paper are each set within a specified numerical range, and the DMDT, DCDT, water absorption per unit area, and water absorption per unit mass of the paper towel sheet are each set within a specified numerical range. The present inventors discovered that the above-described configuration allows for a paper towel roll that is wrinkle-resistant and has good decorative properties without compromising texture, water absorbency, or tear resistance, thereby solving the above-mentioned problems and leading to the completion of the present invention.

[0012] (1) A first aspect of the present invention is a method for manufacturing a paper towel roll, in which an embossed pattern is imparted to at least one ply of base paper made using a TAD paper machine, and the paper towel sheet is laminated into two or three plies and wound into a roll, wherein in the papermaking process using the TAD paper machine, a head box in which a slurry blowing section is branched into at least two layers is used, and in the drying process using a Yankee dryer, when the surface of the wet paper that contacts the drum surface of the Yankee dryer is defined as the "drum surface of the wet paper" and the surface opposite to the "drum surface of the wet paper" is defined as the "hood surface of the wet paper", the blending ratio of softwood bleached kraft pulp (NBKP) on the "hood surface of the wet paper" is 60 mass% or more, and the blending ratio of the NBKP on the "hood surface of the wet paper" is greater than the blending ratio of the NBKP on the "drum surface of the wet paper", and the basis weight per ply of the base paper is 15 g / m 2 More than 30g / m 2The ratio of the tensile strength in the MD direction DMDT to the tensile strength in the CD direction DCDT (DMDT / DCDT) per two plies of the base paper when dry is 0.78 or more and 2.70 or less, the tensile strength in the MD direction DMDT per two or three plies of the paper towel sheet when dry is 2100 cN / 76 mm or more and 6090 cN / 76 mm or less, and the tensile strength in the CD direction DCDT is 1800 cN / 76 mm or more and 5560 cN / 76 mm or less, and the water absorption per unit area of ​​two or three plies of the paper towel sheet is 250 g / m 2 More than 800g / m 2 The following is a method for producing a paper towel roll, characterized in that the water absorption per unit mass is 7 g / g or more and 20 g / g or less.

[0013] (2) A second aspect of the present invention is a method for manufacturing a paper towel roll as described in (1), characterized in that the NBKP content on the "drum surface of the wet paper" is 59 mass% or less.

[0014] (3) A third aspect of the present invention is a method for manufacturing a paper towel roll according to (1) or (2), characterized in that the blending ratio of the NBKP to the hardwood bleached kraft pulp (LBKP) in the entire base paper is NBKP:LBKP = 40-100% by mass: 0-60% by mass.

[0015] (4) A fourth aspect of the present invention is a method for manufacturing a paper towel roll according to (1) or (2), characterized in that in the papermaking process using the TAD papermaking machine, the papermaking speed is 600 m / min or more and 1400 m / min or less.

[0016] (5) A fifth aspect of the present invention is a method for manufacturing a paper towel roll according to (1) or (2), characterized in that the ratio of slurry jet speed to fabric speed (J / W ratio) in the papermaking process is 1.02 or more and 1.12 or less.

[0017] (6) A sixth aspect of the present invention is a method for manufacturing a paper towel roll according to (1) or (2), characterized in that the tensile strength in the MD direction (DMDT) of each of the two plies of base paper when dry is 1800 cN / 76 mm or more and 5200 cN / 76 mm or less.

[0018] (7) A seventh aspect of the present invention is a method for manufacturing a paper towel roll according to (1) or (2), characterized in that the tensile strength in the CD direction (DCDT) of each of the two plies of base paper when dry is 1700 cN / 76 mm or more and 5100 cN / 76 mm or less.

[0019] (8) The eighth aspect of the present invention is a method for manufacturing a paper towel roll according to (1) or (2), characterized in that the paper towel sheet has a concave-convex pattern derived from the papermaking process that is different from the embossed pattern.

[0020] (9) A ninth aspect of the present invention is a method for manufacturing a paper towel roll according to (1) or (2), characterized in that the paper towel sheet has a thickness of 2.0 mm or more and 4.5 mm or less per 10 plies.

[0021] (10) A tenth aspect of the present invention is the method for producing a paper towel roll according to (1) or (2), wherein the specific volume of the paper towel sheet is 7 cm 3 / g or more 23cm 3 / g or less. [Effects of the Invention]

[0022] According to the present invention, a method for producing a wrinkle-free paper towel roll with excellent decorative properties can be provided without reducing the texture, water absorbency, and tear resistance. [Brief explanation of the drawings]

[0023] [Figure 1] 1 is a diagram showing a portion of the papermaking process for the paper towel sheet of the present invention. [Figure 2] FIG. 2 is a diagram showing a cross section of a wet paper in a papermaking process. [Figure 3] FIG. 2 is a diagram showing a cross section of a wet paper web in a Yankee dryer. [Figure 4] FIG. 1 is a perspective view of a paper towel roll according to one embodiment of the present invention. [Figure 5] FIG. 2 is a diagram showing an example of an embossed pattern imparted to the sheet in the paper towel roll of the present invention. [Figure 6] FIG. 1 is a diagram showing a method for measuring the water absorption of a paper towel sheet of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0024] Hereinafter, a mode for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. The following present embodiment is an example for explaining the present invention, and is not intended to limit the present invention to the following content. The present invention can be carried out by appropriately modifying it within the scope of its gist.

[0025] In this specification, "wet paper" refers to a paper web before drying in the papermaking process, "base paper" refers to a paper web that has gone through the papermaking process and has been dried, and "paper towel sheet" refers to a sheet-like product made by laminating two or three plies of base paper, whether or not it is embossed.

[0026] In this specification, "drum surface of wet paper" means the surface where the wet paper comes into contact with the drum surface of the Yankee dryer during the drying process using the Yankee dryer, and in a mechanism like that shown in Figure 1, it is sometimes referred to as the "hot air exposed surface" as the surface that first receives the hot air from the TAD. On the other hand, "hood surface of wet paper" means the surface opposite the "drum surface of wet paper", regardless of whether a Yankee dryer hood (154 in Figure 1) is installed. Also, in a mechanism like that shown in Figure 1, it is sometimes referred to as the "surface opposite the hot air exposed surface." Note that if the wet paper has three or more layers, the "drum surface of wet paper" and "hood surface of wet paper" refer to the outermost layer.

[0027] In this specification, the "MD direction" of a paper towel sheet refers to the machine direction in which the paper towel sheet is made, and the "CD direction" refers to the direction perpendicular to the MD direction (cross direction).

[0028] In this specification, the term "product ply" refers to a paper towel sheet in which the number of plies is in a product state, without peeling off the laminated plies into a single sheet.

[0029] <Manufacturing method for paper towel rolls> A method for manufacturing a paper towel roll 1 (hereinafter simply referred to as "roll 1") according to one embodiment of the present invention involves imparting an embossed pattern 10 to at least one ply of base paper made using a TAD papermaking machine, and laminating the resulting paper towel sheet 1x (hereinafter simply referred to as "sheet 1x") into two or three plies, and winding the resulting sheet into a roll (see Figure 4). The papermaking process using a TAD papermaking machine will be described below.

[0030] <Base paper manufacturing method> 1 shows an embodiment of a papermaking apparatus including a TAD papermaking machine, which is a base paper manufacturing process that is a feature of the present invention. The papermaking apparatus 110 generally includes a twin fabric forming section 120, a water removal section 140, and a web transfer device 160 disposed between the twin fabric forming section 120 and the water removal section 140.

[0031] (Papermaking) First, pulp slurry 104 ejected from a head box 128 is deposited between fabrics 124 and 126, and a paper web (hereinafter also referred to as "wet paper") 105 is formed by a forming roll 122. In this case, the head box 128 used has a slurry ejection section that branches into at least two or more layers.

[0032] (dehydration) Next, the paper web 105 is sent to a dewatering section 170 by fabrics 124 and 126 that are formed into continuous loops by a number of guide rolls 130, and is semi-dewatered by a vacuum (reduced pressure) dewatering device 172. Either or both of the fabrics 124 and 126 may be wire.

[0033] (Stamp) The paper web 105 is then fed by the fabric 126 and the web transport device 160 to the web imprinting device 180. The web imprinting device 180 is a suction device, such as a multi-slot suction box, that in addition to imprinting the paper web 105, can also force unsupported portions of the paper web 105 into the holes of the fabric 126 to further dewater the paper web 105.

[0034] (TAD drying) The paper web 105 is then sent directly by the fabric 126 to through-air dryers (TAD) 142a and 142b, which are the first half of the water removal section 140. The through-air dryers 142a and 142b each have porous cylinders 144a and 144b and hoods 146a and 146b, and hot air is blown in the direction of the arrows. The paper web 105 is continuously dried by passing through these through-air dryers 142a and 142b. Note that only one of the through-air dryers 142a and 142b may be provided.

[0035] (Drying with a Yankee dryer) Finally, the paper web 105 is sent by the fabric 126 and the press roll 132 to a Yankee dryer 150 having a hood 154, which is the latter half of the water removal section 140. The paper web 105 is wound around the barrel surface of a drum 151 filled with steam inside for final drying, and then creped by a doctor blade 152.

[0036] The base paper that has undergone the above papermaking process is then sent to the embossing process and lamination process.

[0037] Although the hoods 146a and 146b of the through-air dryers 142a and 142b and the hood 154 of the Yankee dryer 150 are arranged in opposite directions in the vertical direction in the papermaking apparatus 110 of Fig. 1, they may be arranged in the same direction. Also, the Yankee dryer 150 does not necessarily need to be provided with the hood 154.

[0038] (NBKP content of the "food side of wet paper") FIG. 2 is a diagram showing a cross section of a wet paper 105 in the papermaking process. The blending ratio of softwood bleached kraft pulp (NBKP) in the "hood surface of the wet paper" 105b is 60% by mass or more and 100% by mass or less. If the blending ratio is less than 60% by mass, wrinkles are more likely to occur and the cosmetic properties are reduced. The lower limit of the blending ratio of NBKP in the "hood surface of the wet paper" 105b is preferably 70% by mass or more, and more preferably 80% by mass or more.

[0039] (NBKP content of "wet paper drum surface") The blending ratio of NBKP on the "drum surface of wet paper" 105a is preferably 59% by mass or less. If the blending ratio exceeds 59% by mass, and the blending ratio of NBKP on the "hood surface of wet paper" 105b remains unchanged, the strength will increase and the texture will deteriorate. There are no particular problems with a blending ratio of 0% by mass, but as the blending ratio approaches 0% by mass, the drying efficiency will deteriorate. The lower limit of the blending ratio of NBKP on the "drum surface of wet paper" 105a is more preferably 10% by mass or more, and even more preferably 20% by mass or more. The upper limit is more preferably 55% by mass or less, and even more preferably 50% by mass or less.

[0040] The NBKP (and LBKP) blending ratio on the "drum surface of the wet paper web" 105a is the blending ratio of the NBKP (and LBKP) in the slurry 104 discharged from the head box layer 128a, which is the side closest to the surface where the wet paper web comes into contact with the drum surface of the Yankee dryer when the wet paper web 105 is formed, and the NBKP (and LBKP) blending ratio on the "hood surface of the wet paper web" 105b is the blending ratio of the NBKP (and LBKP) in the slurry 104 discharged from the head box layer 128b, which is the side farthest from the surface where the wet paper web comes into contact with the drum surface of the Yankee dryer when the wet paper web 105 is formed.

[0041] (NBKP content on the wet paper hood surface and wet paper drum surface) In the wet paper 105, the NBKP blending ratio of the "wet paper hood surface" 105b and the "wet paper drum surface" 105a must be higher in the "wet paper hood surface" 105b. If the NBKP blending ratio of the "wet paper hood surface" 105b is lower than the NBKP blending ratio of the "wet paper drum surface 105a," wrinkles are more likely to occur, and the cosmetic properties are reduced.

[0042] The mechanism of action for preventing the occurrence of wrinkles is presumed to be due to the following reason: In the wet paper 105, by lowering the NBKP blending ratio on the "wet paper drum surface" 105a and increasing it on the "wet paper hood surface" 105b, the "wet paper hood surface" 105b becomes relatively harder and the "wet paper drum surface" 105a becomes relatively softer. Therefore, as shown in Figure 3(a), when the wet paper 105 is wrapped around the body surface of the drum 151 of the Yankee dryer 150 and rotates, the "wet paper hood surface" 105b, which is on the outer periphery of the wet paper 105, is harder than the "wet paper drum surface" 105a, making it difficult for wrinkles to form.

[0043] On the other hand, as shown in Figure 3(b), if the "hood surface of the wet paper web" 105b with a high NBKP content is on the drum side and the "drum surface of the wet paper web" 105a with a low NBKP content is on the hood side, it is thought that wrinkles will be more likely to form because the "hood surface of the wet paper web" 105b will be softer than the "drum surface of the wet paper web" 105a.

[0044] (NBKP blend ratio in the entire base paper) The blending ratio of NBKP in the entire base paper is preferably 40% by mass or more and 100% by mass or less. If the NBKP content is less than 40% by mass, the sheet 1x itself will be more likely to tear. There is no particular problem with an NBKP content of 100% by mass, but as the content approaches 100% by mass, the strength of the sheet 1x will increase but the texture may deteriorate. The blending ratio of NBKP is more preferably 45% by mass or more and 90% by mass or less, and even more preferably 50% by mass or more and 80% by mass or less.

[0045] (LBKP blend ratio in the entire base paper) The blending ratio of LBKP in the entire base paper is preferably 0% by mass or more and 60% by mass or less. There is no particular problem if the LBKP content is 0% by mass, but as the LBKP content approaches 0% by mass, the strength of the sheet 1x increases, but the texture may become worse. If the LBKP content exceeds 60% by mass, the sheet 1x itself becomes more prone to tearing. The blending ratio of LBKP is more preferably 10% by mass or more and 55% by mass or less, and even more preferably 20% by mass or more and 50% by mass or less.

[0046] (NBKP, LBKP materials) The NBKP to be blended is preferably pulp made from conifers such as fir, pine, cedar, and cypress, while the LBKP is preferably pulp made from hardwoods such as eucalyptus, poplar, acacia, and oak. Recycled pulp (such as recycled paper pulp from milk cartons) may also be included.

[0047] (Wet pulp blend) In the papermaking process, it is preferable to blend wet pulp. The proportion (content) of wet pulp is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. If the wet pulp content is less than 50% by mass, the water absorbency of the sheet 1x decreases. There is no particular upper limit for the wet pulp content, but if it is too high, the strength of the sheet 1x tends to increase, which may result in a poor texture.

[0048] In this case, wet pulp refers to pulp with a moisture content of preferably 20% by mass or more, more preferably 30% by mass or more, and even more preferably 40% by mass or more, which is significantly different from the moisture content of dry pulp (about 10% by mass).Wet pulp also includes slush pulp (moisture content of about 95 to 97% by mass).

[0049] (J / W ratio) In the papermaking process using a TAD papermaking machine (papermaking apparatus 110), the ratio of slurry jet speed to fabric speed (J / W ratio) is preferably 1.02 or more and 1.12 or less. If the J / W ratio is less than 1.02, the tensile strength ratio (DMDT / DCDT) of the base paper will increase, making the paper towel sheet 1x more likely to tear in the CD direction. If the J / W ratio exceeds 1.12, the tensile strength ratio (DMDT / DCDT) of the base paper will increase, making the paper towel sheet 1x more likely to tear in the CD direction. The lower limit of the J / W ratio is more preferably 1.03 or more, and even more preferably 1.04 or more. The upper limit is more preferably 1.10 or less, and even more preferably 1.08 or less.

[0050] (Paper making speed) The machine speed (papermaking speed) in the papermaking process by the papermaking apparatus 110 is preferably 600 m / min or more and 1400 m / min or less. If the machine speed is less than 600 m / min, the strength of the resulting sheet 1x will be high, but the texture will be poor. If the machine speed exceeds 1400 m / min, the basis weight of the base paper will be low, making it more likely for paper breaks to occur in the papermaking process and reducing operability, and further, when the product has two plies, the water absorbency will be poor. The lower limit of the machine speed is more preferably 650 m / min or more, and even more preferably 700 m / min or more. The upper limit is more preferably 1350 m / min or less, and even more preferably 1300 m / min or less. In this case, the machine speed refers to the rotation speed of the drum 151 of the Yankee dryer 150.

[0051] (Uneven pattern derived from the papermaking process) In the papermaking process, it is preferable that a concave-convex pattern derived from the papermaking process (fabric) different from the embossed pattern 10 described below is applied to the base paper and sheet 1x. Without this concave-convex pattern, the water absorbency of the manufactured sheet 1x will be poor.

[0052] "Originating from the papermaking process" means that the uneven pattern is imparted between the head box 128 of the papermaking machine and the outlet of the Yankee dryer 150 during the papermaking process of the base paper. Specifically, the unevenness can be imparted in a (belt) press section (not shown) located between the press roll 132 and the Yankee dryer 150 in a part of the papermaking apparatus 110 shown in FIG. 1. In the (belt) press section, the uneven pattern can be imparted to the paper web 105 by pressing the paper web 105 and an uneven belt (the uneven belt loops between the (belt) press section and the Yankee dryer 150) together. The uneven belt may be a uneven fabric (wire). Furthermore, when there are multiple fabrics 126 for transporting the paper web 105, unevenness can also be imparted by varying the speed between the fabrics 126.

[0053] The uneven pattern can be changed as needed by changing the fabric pattern (fine pattern, coarse pattern). Changing the uneven pattern will change the specific volume (paper thickness), but it is preferable to select a pattern that will keep the specific volume in the rolled state within a predetermined numerical range.

[0054] The physical properties of the base paper produced through the above-described papermaking process are specified below.

[0055] (basis weight of base paper) The basis weight per ply of base paper is 15 g / m 2 More than 30g / m 2 The basis weight of the base paper is 15 g / m 2 If the sheet is less than 30 g / m², the sheet 1x will be easily torn, and if the product has two plies, the water absorbency will decrease. 2If it exceeds this value, the strength of the sheet 1x will increase, but the texture will deteriorate. The lower limit of the basis weight per ply of base paper is 16 g / m 2 More than 17g / m 2 More preferably, the upper limit is 29 g / m 2 Less than 28 g / m 2 The following is more preferable: The basis weight per ply of the base paper can be measured based on JIS P 8124.

[0056] (DMDT base paper) The dry machine direction tensile strength (DMDT) of each of the two plies of base paper in the dry MD is preferably 1800 cN / 76 mm or more and 5200 cN / 76 mm or less. If the DMDT is less than 1800 cN / 76 mm, the sheet 1x is more likely to tear. If the DMDT is more than 5200 cN / 76 mm, the strength of the sheet 1x increases, but the feel deteriorates. The lower limit of the DMDT is more preferably 2250 cN / 76 mm or more, and even more preferably 2650 cN / 76 mm or more. The upper limit is more preferably 4200 cN / 76 mm or less, and even more preferably 3800 cN / 76 mm or less.

[0057] (Base paper DCDT) The dry cross direction tensile strength (DCDT) in the CD direction per two plies of base paper when dry is preferably 1700 cN / 76 mm or more and 5100 cN / 76 mm or less. If the DCDT is less than 1700 cN / 76 mm, the sheet 1x becomes more likely to tear. If the DCDT exceeds 5100 cN / 76 mm, the strength of the sheet 1x increases, but the feel deteriorates. The lower limit of the DCDT is more preferably 2200 cN / 76 mm or more, and even more preferably 2600 cN / 76 mm or more. The upper limit is more preferably 4100 cN / 76 mm or less, and even more preferably 3700 cN / 76 mm or less.

[0058] (DMDT / DCDT on base paper) The ratio of DMDT to DCDT (DMDT / DCDT) is 0.78 or more and 2.70 or less. If the ratio is less than 0.78, the sheet 1x becomes easily torn. If the ratio exceeds 2.70, when the DMDT is too high, the strength of the sheet 1x increases but the texture deteriorates, and if the DCDT is too low, the sheet 1x becomes easily torn. The lower limit of this ratio is preferably 0.82 or more, more preferably 0.86 or more. The upper limit is preferably 2.10 or less, more preferably 1.85 or less.

[0059] (GMT on the original paper) The GMT (Geometric Tensile Strength), which is the square root of the product of the DMDT and DCDT, has a lower limit of preferably 1749 cN / 76 mm or more, more preferably 2224 cN / 76 mm or more, and even more preferably 2624 cN / 76 mm or more. The upper limit is preferably 5150 cN / 76 mm or less, more preferably 4150 cN / 76 mm or less, and even more preferably 3750 cN / 76 mm or less. If the GMT is less than 1749 cN / 76 mm, the sheet 1x becomes easily torn. If the GMT exceeds 5150 cN / 76 mm, the strength of the sheet 1x increases, but the texture deteriorates.

[0060] The DMDT and DCDT per two plies of base paper are measured in accordance with JIS P 8113. The measurement is performed with two sheets of base paper stacked together (two-ply state). The GMT is calculated by taking the square root of the product of these tensile strengths.

[0061] <Paper towel sheet> The paper towel sheet 1x of the present invention is made by laminating multiple plies of base paper having the above-described characteristics, with at least one ply having an embossed pattern 10. The dimensions, mass, physical properties, etc. of the sheet 1x are as follows:

[0062] (Number of plies in the sheet) The number of plies of the sheet 1x is 2 to 3. If the number of plies is less than 2, the water absorbency of the sheet 1x will be poor. If the number of plies is more than 3, the strength of the sheet 1x will be high, but the texture will be poor.

[0063] (sheet basis weight) The minimum basis weight per ply of sheet 1x is 14.7 g / m 2 More than 15.7g / m 2 More preferably, 16.6 g / m 2 More preferably, the upper limit is 29.4 g / m 2 Less than 28.5 g / m 2 Less than 27.5 g / m is more preferable. 2 More preferably, the sheet 1x has a basis weight of 14.7 g / m 2 If the sheet 1x has a basis weight of less than 29.4 g / m, the sheet 1x will be easily torn, and when the product has two plies, the water absorbency will decrease. 2 If the weight exceeds this value, the texture of the sheet 1x will deteriorate. The basis weight per ply of the sheet 1x can be measured based on JIS P 8124.

[0064] (sheet thickness) The thickness of the sheet 1x per 10 plies is preferably 2.0 mm or more and 4.5 mm or less. If the thickness of the sheet 1x is less than 2.0 mm, the water absorption of the sheet 1x will be poor, and if it exceeds 4.5 mm, the sheet 1x will be prone to tearing if the basis weight of the sheet 1x remains unchanged. The lower limit of the thickness of the sheet 1x is more preferably 2.3 mm or more, and even more preferably 2.6 mm or more. The upper limit is more preferably 4.2 mm or less, and even more preferably 4.0 mm or less.

[0065] The thickness of each of the 10 plies of sheet 1x can be measured using a thickness gauge (a dial thickness gauge called "PEACOCK" manufactured by Ozaki Seisakusho Co., Ltd.). The measurement conditions are a measurement load of 3.7 kPa, a probe diameter of 30 mm, and a sample placed between the probe and the measuring table. The gauge is read when the probe is lowered at a speed of 1 mm per second or less. The sample is measured using 10 plies of sheet 1x (5 sets for 2 plies, 3 sets for 3 plies, and the value is proportionally calculated to 10 plies). The measurement is also repeated 10 times at different locations, and the average of the measurement results is used as the final thickness of sheet 1x.

[0066] (seat length) The sheet 1x preferably has perforations 1c formed in the sheet width direction (X direction in FIG. 4) at approximately equal intervals in the roll winding direction (Y direction in FIG. 4). The lower limit of the sheet length (length in the Y direction in FIG. 4), which is the distance between adjacent perforations 1c, is preferably 100 mm or more, 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 220 mm or less, and even more preferably 210 mm or less. If the sheet length is less than 100 mm, the water absorbency per sheet of the sheet 1x will be poor. If the sheet length exceeds 250 mm, the sheet area will be too large, making the sheet 1x more likely to tear in unintended places.

[0067] (specific volume of sheet) The specific volume of 1 sheet is 7cm 3 / g or more 23cm 3 / g or less. The specific volume of sheet 1x is 7 cm 3 If the specific volume of the sheet 1x is less than 23 cm3 / g, the water absorption of the sheet 1x will be poor. 3 If the sheet 1x exceeds 9 cm / g, the sheet 1x will be more likely to tear if the basis weight of the sheet 1x does not change, because the paper thickness and specific volume will increase instead. 3 / g or more is more preferable, and 11cm 3 / g or more is more preferable. The upper limit is 22 cm 3 / g or less is more preferable, and 17cm 3The specific volume is calculated by dividing the thickness of one ply of sheet 1x by the basis weight per ply (the thickness of one product ply divided by the basis weight per product ply) to obtain the volume (cm 3 ) per unit (g). 3 )

[0068] (DMDT sheets) The dry machine direction tensile strength (DMDT) of sheet 1x per two or three plies in the dry state is 2100 cN / 76 mm or more and 6090 cN / 76 mm or less. If the DMDT of sheet 1x is less than 2100 cN / 76 mm, sheet 1x itself becomes more prone to tearing. If the DMDT of sheet 1x exceeds 6090 cN / 76 mm, the strength of sheet 1x increases but the texture deteriorates. The lower limit of the DMDT of sheet 1x is preferably 2600 cN / 76 mm or more, more preferably 3100 cN / 76 mm or more. The upper limit is preferably 4920 cN / 76 mm or less, more preferably 4450 cN / 76 mm or less.

[0069] (Seat DCDT) The dry cross direction tensile strength (DCDT) of sheet 1x per 2-ply or 3-ply in the CD direction when dry is 1800 cN / 76 mm or more and 5560 cN / 76 mm or less. If the DCDT of sheet 1x is less than 1800 cN / 76 mm, sheet 1x itself becomes more prone to tearing. If the DCDT of sheet 1x exceeds 5560 cN / 76 mm, the strength of sheet 1x increases but the texture deteriorates. The lower limit of DCDT of sheet 1x is preferably 2400 cN / 76 mm or more, more preferably 2800 cN / 76 mm or more. The upper limit is preferably 4470 cN / 76 mm or less, more preferably 4040 cN / 76 mm or less.

[0070] (Sheet (DMDT / DCDT)) The ratio of DMDT to DCDT in sheet 1x (DMDT / DCDT) preferably has a lower limit of 0.78 or more, more preferably 0.82 or more, and even more preferably 0.86 or more. The upper limit is preferably 2.70 or less, more preferably 2.10 or less, and even more preferably 1.85 or less. If the ratio is less than 0.78 and the DCDT is too high, sheet 1x will have high strength but poor texture, and if the DMDT is too low, sheet 1x will be prone to tearing. If the ratio exceeds 2.70 and the DMDT is too high, sheet 1x will have high strength but poor texture, and if the DCDT is too low, sheet 1x will be prone to tearing. Note that when calculating the ratio of DMDT to DCDT (DMDT / DCDT), if DMDT is used per 2 plies, DCDT is also calculated as the value per 2 plies, and if DMDT is used per 3 plies, DCDT is also calculated as the value per 3 plies.

[0071] (GMT on the sheet) The GMT (Geometric Tensile Strength) of sheet 1x, which is the square root of the product of the DMDT and DCDT, preferably has a lower limit of 1944 cN / 76 mm or more, more preferably 2497 cN / 76 mm or more, and even more preferably 2947 cN / 76 mm or more. The upper limit is preferably 5820 cN / 76 mm or less, more preferably 4690 cN / 76 mm or less, and even more preferably 4240 cN / 76 mm or less. If the GMT of sheet 1x is less than 1944 cN / 76 mm, sheet 1x itself becomes more prone to tearing. If the GMT of sheet 1x exceeds 5820 cN / 76 mm, sheet 1x's strength increases but its texture deteriorates. Note that when DMDT is calculated per two plies, DCDT is also calculated as a value per two plies, and when DMDT is calculated per three plies, DCDT is also calculated as a value per three plies.

[0072] The DMDT and DCDT for 2 or 3 plies of sheet 1x are measured in accordance with JIS P 8113. The GMT is calculated as the square root of the product of these tensile strengths. If sheet 1x is 3 plies, the measurement is similarly performed in accordance with JIS P 8113, but the conditions are changed to 3 plies.

[0073] (Water absorption capacity of sheet <unit area>) The water absorption per unit area of ​​sheet 1x in 2-ply or 3-ply (hereinafter simply referred to as "water absorption <unit area>") is 250 g / m 2 More than 800g / m 2 Water absorption <unit area> is 250g / m or less. 2 If the water absorption capacity (unit area) is less than 800 g / m, the water absorption capacity of the sheet 1x will be poor. 2 If the basis weight of sheet 1x does not change, the sheet thickness and specific volume will increase, making sheet 1x more likely to tear. The lower limit of water absorption <unit area> is 300g / m 2 More than 350g / m 2 More preferably, the upper limit is 750 g / m 2 Preferably less than 700 g / m 2 The following is more preferred:

[0074] (Water absorption capacity of sheet <unit mass>) The water absorption per unit mass of the sheet 1x in 2-ply or 3-ply (hereinafter simply referred to as "water absorption <unit mass>") is 7 g / g or more and 20 g / g or less. If the water absorption <unit mass> is less than 7 g / g, the water absorption of the sheet 1x will be poor. If the water absorption <unit mass> is more than 20 g / g, if the basis weight of the sheet 1x remains unchanged, the paper thickness and specific volume will increase instead, making the sheet 1x more likely to tear. The lower limit of the water absorption <unit mass> is preferably 8 g / g or more, more preferably 9 g / g or more. The upper limit is preferably 18 g / g or less, more preferably 17 g / g or less.

[0075] The method for measuring the water absorption amount (unit area) and the water absorption amount (unit mass) of the sheet 1x will be described below with reference to FIG. (1) A sheet 1x made up of two plies is taken and cut using a square template with one side measuring 7.6 cm to prepare a rectangular test piece 20 with one side measuring 7.6 cm. (2) The mass of the test piece 20 is measured with an electronic balance before absorbing water. (3) The test piece 20 is set in a holder 21 (a jig for fixing three points of the test piece 20, the jig being made of a metal that does not absorb moisture). (4) Distilled water is poured into a commercially available tray to a depth of 2 cm, and the test piece 20 set in the holder 21 is immersed in the distilled water for 2 minutes. (5) After immersion for 2 minutes, the test piece 20 together with the holder 21 is removed from the distilled water, and as shown in Figure 6, the holder 21 and the test piece 20 are hung on a rod placed in an empty water tank with the corner 20a facing up, the lid of the water tank is closed, and the test piece is left for 5 minutes. (6) Then, the holder 21 and the test piece 20 are taken out of the water tank, the holder 21 is removed, and the mass of the test piece 20 is measured using an electronic balance. (7) From the change in mass of the test piece 20 before and after immersion in distilled water, the amount of distilled water absorbed per unit area of ​​the test piece 20 (g of water / sheet m 2 , 1m 2 Hit. Abbreviated as g / m 2 ) is calculated. (8) Furthermore, the water absorption per unit area (g of water / sheet m 2 ) by the basis weight of the product ply of the test piece 20 to obtain the water absorption per unit area (water g / sheet m 2 ) / basis weight (sheet g / sheet m 2 ) = Water absorption per unit mass (g of water / g of sheet, per 1g. Abbreviated as g / g). Measurements are carried out five times for each sample, and the average value is used.

[0076] When the sheet 1x is three-ply, it is preferable to measure it in the same manner as when it is two-ply. This measurement is carried out in accordance with JIS P 8111 at a temperature of 23±1°C and a humidity of 50±2%. The distilled water is also kept at 23±1°C.

[0077] (Embossed) The sheet 1x is embossed and has an embossed pattern 10. The sheet 1x of the present invention is embossed into at least one ply and then laminated to form two or three plies. When laminating two or three plies, it is preferable to use, for example, ply bond glue to apply the glue and perform the bonding process. By bonding the two or three plies in this way, the plies are bonded together strongly, and even if the sheet 1x gets wet, the plies will not peel off and will not tear. Furthermore, water may be used instead of ply bond glue, or glue and water may be mixed.

[0078] It is preferable that an embossed pattern 10 is provided on the ply on the surface 1a side of the sheet 1x. By providing the embossed pattern 10 on the surface 1a side, glue can be applied to the embossed portion and two or three plies can be laminated. If the embossed pattern 10 is not provided on the sheet 1x, the water absorption of the sheet 1x will be poor. In addition, since ply bond glue will be applied to the entire surface of the sheet 1x, the texture will be poor.

[0079] 5 is a diagram showing an example of an embossing pattern 10 in a roll 1 (sheet 1x). The embossing pattern 10 preferably includes radial embossments 11 and closed-ring structure embossments 12, and the radial embossments 11 and the closed-ring structure embossments 12 are alternately arranged at equal intervals. By including the radial embossments 11 and the closed-ring structure embossments 12 in the embossing pattern 10, the sheet 1x can have excellent texture and water absorbency.

[0080] The overall shape of the radial embossments 11 is not particularly limited, but it is preferable that the embossed pattern 10 has a plurality of linear embossments extending from the center to the outside or a plurality of embossments in a shape made up of straight lines. When the embossed pattern 10 includes the radial embossments 11, the texture of the sheet 1x is improved. The closed-ring structure embossment 12 is not particularly limited in overall shape, as is the case with the radial embossment 11, but preferably has a linear or geometric embossment provided in the center and a geometric embossment surrounding it to form a closed ring on the outside. When the embossment pattern 10 includes the closed-ring structure embossment 12, the water absorbency of the sheet 1x is improved.

[0081] The embossed pattern 10 includes linear embossed portions 100, and the proportion of the linear embossed portions 100 in the embossed pattern 10 is preferably 20% or more. If the proportion is less than 20%, the embossed pattern 10 will not contribute to improving the texture and water absorbency, resulting in poor texture and water absorbency of the sheet 1x. The proportion of the linear embossed portions 100 in the embossed pattern 10 is more preferably 50% or more, and even more preferably 90% or more.

[0082] In this case, the linear embossed portion 100 refers to an embossment having a thickness of 0.1 mm to 4 mm and a length of 5 mm or more. The proportion of the linear embossed portion 100 is calculated as follows. (1) Divide any 100 mm x 100 mm area on the surface of sheet 1x on which embossed pattern 10 is applied into 10 mm squares. (2) Calculate the proportion of the linear embossed portion 100 using the following formula. If a single square contains both linear embossing and dot embossing, the square with the larger embossing occupancy is used. (Number of squares containing linear embossing / Number of squares containing any embossing) x 100 = Percentage of linear embossing in 100 (%)

[0083] The ply on the back surface 1b side of the sheet 1x is not particularly limited as to whether it has the embossed pattern 10, as long as it has a concavo-convex pattern 13 derived from the papermaking process that is different from the embossed pattern 10 described below. Nested embossing or pin-to-pin embossing may be provided, or no embossing may be provided, but nested embossing or no embossing is preferred, and no embossing is more preferred.

[0084] When the sheet 1x is three-ply, the ply between the ply on the front surface 1a side and the ply on the back surface 1b side may or may not be provided with an embossed pattern 10, but it is preferable that the two plies on the front side have an embossed pattern 10 and the back side has no embossing.

[0085] <Paper towel roll> The paper towel sheet 1x described above is wound into a roll to produce a paper towel roll 1 as shown in Figure 4. As shown in Figure 4, the surface of the sheet 1x facing the outside of the roll is referred to as surface 1a (surface of sheet 1x), and the surface facing the center of the roll is referred to as back surface 1b (back surface of sheet 1x). In addition, the edge of sheet 1x is referred to as the outermost edge 1e of roll 1.

[0086] The dimensions, mass, physical properties, etc. of the roll 1 are as follows:

[0087] (Volume length) The lower limit of the winding length of the roll 1 is preferably 18 m or more, more preferably 22 m or more, and even more preferably 25 m or more. The upper limit is preferably 45 m or less, more preferably 40 m or less, and even more preferably 31 m or less. If the winding length is less than 18 m, the water absorbency per roll of the roll 1 will be poor. If the winding length exceeds 45 m, and the winding diameter DR remains the same, the basis weight will be lower, making the sheet 1x more likely to tear, and if the product ply is two-ply, the water absorbency will also be poor.

[0088] The roll length is measured as follows. First, the space between adjacent perforations 1c on roll 1 is counted as one sheet, and the length of 10 sheets is measured. Then, the total number of sheets on roll 1 is counted, and the roll length is calculated proportionally from the length of 10 sheets and the number of sheets. For example, if the length of 10 sheets is 1.80m and there are 150 sheets, the roll length is 1.80m x (150 / 10) = 27m. Note that if roll 1 does not have perforations 1c, the roll length is measured.

[0089] (roll diameter) The lower limit of the winding diameter of the roll 1 (DR in FIG. 4) is preferably 130 mm or more, more preferably 135 mm or more, and even more preferably 142 mm or more. The upper limit is preferably 170 mm or less, more preferably 165 mm or less, and even more preferably 156 mm or less. If the winding diameter is less than 130 mm and the winding length and winding density remain unchanged, the basis weight will be lower, making the sheet 1x more prone to tearing and, when the product ply is two-ply, reducing its water absorbency. If the winding diameter exceeds 170 mm and the winding length and winding density remain unchanged, the basis weight will be higher, making the feel of the sheet 1x worse.

[0090] The winding diameter (DR) of the roll 1 is measured using a diameter rule manufactured by Muratec KDS Co., Ltd. Three rolls 1 are measured, and the measurement results are averaged.

[0091] (sheet width) The lower limit of the sheet width of the roll 1 (W in FIG. 4) (hereinafter also referred to as "roll width") is preferably 260 mm or more, more preferably 270 mm or more, and even more preferably 275 mm or more. The upper limit is preferably 300 mm or less, more preferably 290 mm or less, and even more preferably 286 mm or less. If the sheet width is less than 260 mm, the water absorbency per sheet of the sheet 1x will be poor. If the sheet width exceeds 300 mm, the sheet area will be too large, making the sheet 1x more likely to tear in unintended places.

[0092] (roll mass) The lower limit of the roll mass of the roll 1 is preferably 240 g or more, more preferably 260 g or more, and even more preferably 280 g or more. The upper limit is preferably 500 g or less, more preferably 470 g or less, and even more preferably 430 g or less. If the roll mass is less than 240 g, and the winding length remains unchanged, the basis weight becomes lower, making the sheet 1x more prone to tearing and, when the product ply is two-ply, reducing the water absorbency. If the roll mass exceeds 500 g, and the winding length remains unchanged, the basis weight becomes higher, and the texture of the sheet 1x deteriorates.

[0093] The roll mass is the mass per 280mm of sheet width, excluding the paper tube (core) 1d of roll 1. If the sheet width is not 280mm, convert it to the mass per 280mm by proportional calculation.

[0094] (roll density) The lower limit of the roll density of Roll 1 is 0.04 g / cm 3 More than 0.05 g / cm is preferable. 3 More preferably, 0.06 g / cm or more 3 The upper limit is 0.12 g / cm. 3 Preferably less than 0.11 g / cm 3 Less than 0.10 g / cm is more preferable. 3 More preferably, the roll density is 0.04 g / cm 3 If the roll density is less than 0.12 g / cm, the volume of roll 1 remains the same, but the basis weight decreases, making sheet 1x more likely to tear and reducing its water absorption when the product has two plies. 3 If the roll volume does not change, the basis weight will increase instead, resulting in a poor texture of the sheet 1x.

[0095] Roll density is expressed as (roll mass) ÷ (roll volume). Roll mass is the mass of roll 1 per 280 mm of sheet width. Roll volume is expressed as [{cross-sectional area of ​​roll outer diameter (winding diameter DR)} - (cross-sectional area of ​​paper tube (core) outer diameter DI)] × sheet width (converted to per 280 mm). For example, if the roll mass (excluding paper tube (core)) per 280 mm of sheet width is 382 g, the winding diameter DR is 150 mm, and the paper tube (core) outer diameter DI is 39 mm, roll density = 382 g ÷ [{3.14 × (150 mm ÷ 2 ÷ 10) 2 -3.14×(39mm÷2÷10) 2}×(280mm÷10)]=0.08g / cm 3 This becomes:

[0096] (winding density) The winding density of roll 1 has a lower limit of 0.28 m / cm 2 More than 0.30m / cm is preferable. 2 More preferably, 0.32 m / cm or more 2 The upper limit is 0.45 m / cm. 2 Preferably less than 0.43m / cm 2 Less than 0.41m / cm is more preferable. 2 More preferably, the winding density is 0.28 m / cm 2 If the winding density is less than 0.45 m / cm, the roll 1 is wound too loosely, which makes the roll 1 prone to dents and reduces the cosmetic properties. 2 If the tension exceeds this value, roll 1 will be pulled to make it tightly wound, resulting in a lower basis weight, making sheet 1x more likely to tear, and also reducing water absorption when the product ply is two-ply.

[0097] The winding density is expressed as (winding length x number of plies) ÷ (cross-sectional area of ​​the roll). The cross-sectional area of ​​the roll is expressed as {cross-sectional area of ​​the roll outer diameter (winding diameter DR) - (cross-sectional area of ​​the paper tube (core) outer diameter DI)}. For example, in the case of a winding length of 27 m, 2 plies, winding diameter DR of 150 mm, and paper tube (core) outer diameter DI of 39 mm, the winding density = (27 m x 2) ÷ {3.14 x (150 mm ÷ 2 ÷ 10) 2 -3.14×(39mm÷2÷10) 2}=0.33m / cm 2 This becomes:

[0098] (Outer diameter of paper tube (core)) The outer diameter (DI in FIG. 4, hereinafter simply referred to as "DI") of the cardboard tube (core) 1d of the roll 1 preferably has a lower limit of 20 mm or more, more preferably 30 mm or more, and even more preferably 36 mm or more. The upper limit is preferably 60 mm or less, more preferably 55 mm or less, and even more preferably 52 mm or less. If the DI is less than 20 mm and the winding diameter remains unchanged, the winding density will be low, resulting in the roll 1 being wound too softly and prone to dents, and the decorative properties will be reduced. If the DI exceeds 60 mm and the winding diameter remains unchanged, the winding density will be high, resulting in a low basis weight, making the sheet 1x more prone to tearing, and in addition, when the product ply is two-ply, the water absorbency will be reduced.

[0099] DI is measured using a diameter rule manufactured by Muratec KDS Co., Ltd. Three paper towel rolls 1 are measured and the results are averaged. If there is no paper tube (core), the diameter of the cavity is measured.

[0100] (Paper tube (core) mass) The mass of the cardboard tube (core) 1d of the roll 1 (hereinafter simply referred to as "core mass") is preferably 10g or more, more preferably 12g or more, and even more preferably 14g or more. The upper limit is preferably 25g or less, more preferably 20g or less, and even more preferably 17g or less. If the core mass is less than 10g, the cardboard tube (core) 1d becomes easily crushed, making it difficult to maintain the shape of the roll and making wrinkles more likely to occur, resulting in a decrease in decorativeness. If the core mass exceeds 25g, the cardboard tube (core) 1d becomes hard and requires a large force to cut with a log saw, making wrinkles more likely to occur in the sheet 1x during cutting, resulting in a decrease in decorativeness.

[0101] The core mass of roll 1 is the mass of the paper tube (core) 1d per 280 mm of sheet width in roll 1, and if the sheet width is not 280 mm, it is converted to the mass per 280 mm by proportional calculation.

[0102] (Paper core material) From the viewpoint of strength, the paper tube (core) 1d preferably contains bleached pulp (BKP). The content of BKP in the paper tube (core) 1d is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. Similarly, from the viewpoint of strength, the content of LBKP in the BKP contained in the paper tube (core) 1d is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more.

[0103] As described above, according to this embodiment, a method for manufacturing a wrinkle-free and aesthetically pleasing paper towel roll can be provided without compromising texture, absorbency, or tear resistance.

[0104] Applications of paper towel rolls include, for example, rolls of kitchen paper (sometimes called kitchen towels, cooking paper, etc.) used in home kitchens and restaurant kitchens to wipe away moisture or oil and remove dirt, as well as rolls of other sanitary paper.

[0105] Although the present invention has been described above using embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be apparent to those skilled in the art that various modifications and improvements can be made to the above embodiments. Furthermore, it is clear from the claims that such modifications and improvements can also be included within the technical scope of the present invention. [Example]

[0106] The present invention will be described in detail below with reference to examples, but the present invention is not limited to the examples shown below.

[0107] The paper towel rolls of Examples 1 to 13 and Comparative Examples 1 to 5 shown in Tables 3 and 4 were manufactured through the following steps: (1) papermaking and creping, (2) embossing and bonding (laminating), and (3) roll winding. The paper towel rolls of all Examples and Comparative Examples were measured for the above-mentioned parameters and evaluated as follows. For each of the following evaluations, 1 point was considered a failure and 2 points or more was considered a pass. Furthermore, each parameter other than the following evaluations was measured according to the standards or measurement methods described above.

[0108] 1. The texture of a paper towel sheet The texture of the paper towel sheets after production was evaluated by 30 panelists when they were held in their hands, and the number of panelists who felt that the texture of the sheets was poor was rated on a four-point scale. The evaluation criteria were as follows: 4: 0-1 people felt that the seat had poor texture 3: 2-4 people felt that the seat had poor texture 2: 5-7 people felt that the seat had poor texture. 1: Eight or more people felt that the seat had poor texture

[0109] 2. Absorbency of paper towel sheets The water absorbency of the paper towel sheets after production was evaluated on a four-level scale based on the measurement results of the amount of water absorbed per unit area and per unit mass of the product ply. The evaluation criteria are shown in Table 1 below. [Table 1]

[0110] 3. Paper towel sheets are tear-resistant The tear resistance of the paper towel sheets after production was evaluated on a four-point scale using DMDT and DCDT on the product ply. The evaluation criteria are shown in Table 1 below. [Table 2]

[0111] 4. Cosmetic properties of paper towel sheets After manufacturing, the paper towel roll was pulled out from start to finish, and the presence or absence of wrinkles throughout the roll was evaluated by 30 panelists. The number of panelists who felt that the roll was "wrinkled and less aesthetically pleasing" was rated on a four-point scale. The evaluation criteria were as follows: 4: 0-1 people felt that the product had wrinkles and was less cosmetically appealing 3: 2-4 people felt that the product had wrinkles and was less cosmetically appealing 2: 5-7 people felt that the product had wrinkles and was less cosmetically appealing 1: Eight or more people felt that the product had wrinkles and was less cosmetically appealing

[0112] [Table 3]

[0113] [Table 4]

[0114] As is clear from the results shown in Tables 3 and 4, the paper towel rolls of Examples 1 to 13 were good in terms of texture, absorbency, and tear resistance, and also had good wrinkle-free aesthetics. In contrast, the paper towel rolls of Comparative Examples 1 to 5 were poor in any of the texture, absorbency, tear resistance, and wrinkle-free aesthetics. Therefore, it was confirmed that the method for manufacturing a paper towel roll of the present invention can provide a method for manufacturing a wrinkle-free paper towel roll with excellent aesthetics without compromising texture, water absorbency, or tear resistance. [Explanation of symbols]

[0115] 1 paper towel roll 1a surface 1b back side 1c perforation 1d paper core 1e The outermost edge of a paper towel roll 1x Paper Towel Sheet 10 Embossing Pattern 11 Radial Embossing 12 Closed ring structure embossing 13 Concave and convex patterns 20 test specimens 20a Corner 21 Holder 100 Linear embossed part 104 Pulp slurry (slurry) 105 Paper web (wet paper) 105a Wet paper drum surface 105b Wet paper hood surface 110 Paper making equipment 120 Twin Fabric Forming Section 122 Forming Roll 124,126 Fabric 128, 128a, 128b Headbox (Layer) 130 Guide Roll 132 Press Roll 140 Water Removal Section 142a, 142b Through Air Dryer (TAD) 144a, 144b Porous cylinder 146a,146b TAD hood 150 Yankee Dryer 151 Drums 152 Doctor Blade 154 Yankee Dryer Hood 160 Web transfer device 170 Dewatering Section 172 Vacuum (reduced pressure) dehydration equipment 180 Web stamping device

Claims

1. A method for producing a paper towel roll, comprising: providing an embossed pattern to at least one ply of base paper made using a TAD paper machine; laminating the resulting two-ply or three-ply paper towel sheet; and winding the resulting paper towel sheet into a roll; In the papermaking process using the TAD papermaking machine, a headbox having a slurry blowing section branched into at least two layers is used, In the drying process using a Yankee dryer, when the surface of the wet paper that contacts the drum surface of the Yankee dryer is defined as the "drum surface of the wet paper" and the surface opposite to the "drum surface of the wet paper" is defined as the "hood surface of the wet paper", the blending ratio of softwood bleached kraft pulp (NBKP) on the "hood surface of the wet paper" is 60% by mass or more, and The blending ratio of the NBKP on the "hood surface of the wet paper web" is greater than the blending ratio of the NBKP on the "drum surface of the wet paper web", The basis weight of one ply of the base paper is 15 g / m ２ 30g / m or more ２ Below, the ratio of the tensile strength in the MD direction DMDT to the tensile strength in the CD direction DCDT (DMDT / DCDT) per two plies of the base paper when dry is 0.78 or more and 2.70 or less, The tensile strength DMDT in the MD direction of the paper towel sheet per two or three plies when dry is 2100 cN / 76 mm or more and 6090 cN / 76 mm or less, and the tensile strength DCDT in the CD direction is 1800 cN / 76 mm or more and 5560 cN / 76 mm or less, The water absorption per unit area of ​​the paper towel sheet in two or three plies is 250 g / m ２ 800g / m or more ２ The following describes a method for producing a paper towel roll, characterized in that the water absorption per unit mass is 7 g / g or more and 20 g / g or less.

2. The method for manufacturing a paper towel roll according to claim 1, wherein the blending ratio of the NBKP on the "drum surface of the wet paper" is 59% by mass or less.

3. 3. The method for producing a paper towel roll according to claim 1, wherein the blending ratio of the NBKP to the hardwood bleached kraft pulp (LBKP) in the entire base paper is NBKP:LBKP = 40 to 100% by mass: 0 to 60% by mass.

4. 3. The method for manufacturing a paper towel roll according to claim 1, wherein the papermaking speed in the papermaking process using the TAD papermaking machine is 600 m / min or more and 1400 m / min or less.

5. 3. The method for manufacturing a paper towel roll according to claim 1, wherein the ratio of slurry jet speed to fabric speed (J / W ratio) in the papermaking process is 1.02 or more and 1.12 or less.

6. The method for manufacturing a paper towel roll according to claim 1 or 2, wherein the tensile strength DMDT in the machine direction when dry per two plies of the base paper is 1800 cN / 76 mm or more and 5200 cN / 76 mm or less.

7. 3. The method for manufacturing a paper towel roll according to claim 1, wherein the tensile strength (DCDT) in the CD direction per two plies of the base paper when dry is 1700 cN / 76 mm or more and 5100 cN / 76 mm or less.

8. The method for manufacturing a paper towel roll according to claim 1 or 2, wherein the paper towel sheet has a concave-convex pattern derived from a papermaking process that is different from the embossed pattern.

9. 3. The method for manufacturing a paper towel roll according to claim 1, wherein the paper towel sheet has a thickness of 2.0 mm or more and 4.5 mm or less per 10 plies.

10. The specific volume of the paper towel sheet is 7 cm ３ / g or more 23cm ３ The method for producing a paper towel roll according to claim 1 or 2, wherein the water content is 1 / g or less.

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