Kitchen towel roll

Abstract

To provide a kitchen towel roll, even in a case of a long kitchen towel roll, having excellent absorbency and softness, easily attached to a paper holder and further, when having been attached to the paper holder, easily cut at perforations from a beginning to an end of use of the roll.SOLUTION: A kitchen towel roll is formed by winding a paper towel with perforations in an axial direction into a roll shape. The paper towel has a water absorption per unit area of 320 g / m2 or more and 600 g / m2 or less, a root mean square height of surface roughness of 35 μm or more and 170 μm or less, a tensile strength in an MD direction of the perforations (perforation DMDT) when the paper towel is dry of 405 cN / 75 mm or more and 1470 cN / 75 mm or less, a roll length of 18 m or more and 50 m or less, and a roll diameter of 125 mm or more and 175 mm or less.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to kitchen towel rolls. [Background technology]

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

[0003] Paper towels are used frequently for a wide variety of purposes, including cooking and cleaning. However, compared to toilet paper rolls, they are wound shorter per roll and require fewer cuts, leading to more frequent replacement. Longer paper towels with longer roll lengths have been developed, but while they may boast superior absorbency, they tend to be thinner and less absorbent than non-long products because they are tightly wound. On the other hand, if the roll is not tightly wound, the roll diameter increases, making it difficult to fit into a paper holder. Thus, it has been difficult to achieve the qualities of softness and long length in kitchen towel rolls, while maintaining absorbency.

[0004] Furthermore, because a long kitchen towel roll attached to a paper holder is heavy, the weight of the kitchen towel roll makes it difficult to rotate at first. Furthermore, if the perforations in the paper towel are weak, the paper towel may be accidentally torn at the perforations while being pulled out of the paper holder. Therefore, if no perforations are provided or the strength of the perforations is increased, the paper towel can be cut at the desired position at the beginning of use, but as the roll becomes lighter toward the end of use, it becomes difficult to cut the paper towel. Furthermore, if the strength of the paper towel is increased, the strength of the perforations increases, making it similarly difficult to cut, and the softness of the sheet also decreases.

[0005] As disclosed in Patent Document 1, TAD (through air drying) paper towels are known to have good softness and water absorbency.

[0006] When they attempted to make long kitchen towel rolls using TAD paper towels, they found that the surface of TAD paper towels had unevenness inherent to papermaking, which was different from the embossing, weakening the strength of the perforations and making it difficult to maintain strength suitable for cutting from the beginning to the end of the roll. It was speculated that the cause of this was that the unevenness of the paper towel surface tended to loosen or break the bonds between the fibers, weakening the strength of the perforation joints and affecting the strength of the perforations. Furthermore, because paper has the tendency to break from its weakest point, it was speculated that the perforation joints, which overlap with the embossing, were particularly prone to breaking. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Japanese Patent Application Publication No. 2024-016101 Summary of the Invention [Problem to be solved by the invention]

[0008] To provide a kitchen towel roll which has been made in view of the above circumstances and which is excellent in water absorption and softness even when it is a long kitchen towel roll, is easy to mount on a paper holder, and further, when mounted on the paper holder, the perforations can be easily cut from the beginning to the end of use of the roll. [Means for solving the problem]

[0009] The inventors conducted extensive research and discovered that the above problems could be solved by specifying the amount of water absorbed per unit area of ​​the paper towel, its surface roughness, the tensile strength of the perforations when dry, the roll length, and the roll diameter in a kitchen towel roll made of paper towels with axial perforations wound into a roll, and thus completed the present invention.

[0010] (1) A first aspect of the present invention is a kitchen towel roll in which a paper towel having perforations in the axial direction is wound into a roll, and the paper towel has a water absorption capacity per unit area of ​​320 g / m 2 More than 600g / m 2 The kitchen towel roll is characterized by having a surface roughness root mean square height of 35 μm or more and 170 μm or less, a tensile strength in the MD direction of the perforations when the paper towel is dry (perforation DMDT) of 405 cN / 75 mm or more and 1470 cN / 75 mm or less, a winding length of 18 m or more and 50 m or less, and a winding diameter of 125 mm or more and 175 mm or less.

[0011] (2) A second aspect of the present invention is a kitchen towel roll as described in (1), characterized in that the paper towel has a perforation bond ratio of 10% or more and 30% or less, where the perforation bond ratio is the length of the joint of the perforation divided by the length of the cut portion of the perforation plus the length of the joint of the perforation.

[0012] (3) A third aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the paper towel has an uneven pattern on its surface resulting from the papermaking process.

[0013] (4) A fourth aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the paper towels are wound around a core, and the roll mass per 280 mm of roll width excluding the core is 190 g or more and 620 g or less.

[0014] (5) The fifth aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the length of the joint of the perforations is 0.5 mm or more and 2.0 mm or less.

[0015] (6) The sixth aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the length of the cut portion of the perforation is 2.0 mm or more and 7.0 mm or less.

[0016] (7) A seventh aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the MD tensile strength (DMDT) of the portion of the paper towel that does not include the perforations when the paper towel is dry is 2100 cN / 75 mm or more and 4500 cN / 75 mm or less.

[0017] (8) The eighth aspect of the present invention is the kitchen towel roll according to (7), characterized in that the ratio of the perforation DMDT to the DMDT is 0.14 or more and 0.44 or less.

[0018] (9) A ninth aspect of the present invention is the kitchen towel roll according to (4), characterized in that the ratio of the perforation DMDT to the roll mass is 1.1 or more and 4.0 or less.

[0019] (10) A tenth aspect of the present invention is the kitchen towel roll according to (1) or (2), wherein the basis weight of the product ply of the paper towel is 33 g / m 2 More than 65g / m 2 It is characterized by the following:

[0020] (11) The eleventh aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the paper thickness per 10 plies of the paper towel is 2.2 mm or more and 5.3 mm or less.

[0021] (12) A twelfth aspect of the present invention is the kitchen towel roll according to (1) or (2), wherein the specific volume of the paper towel is 8.0 cm 3 / g or more 23.0cm 3 / g or less.

[0022] (13) The thirteenth aspect of the present invention is a kitchen towel roll according to (1) or (2), characterized in that the water absorption per unit mass of the paper towel is 8.0 g / g or more and 13.5 g / g or less.

[0023] (14) A fourteenth aspect of the present invention is the kitchen towel roll according to (1) or (2), wherein the roll density is 0.03 g / cm 3 More than 0.20g / cm 3 It is characterized by the following:

[0024] (15) The fifteenth aspect of the present invention is the kitchen towel roll according to (1) or (2), wherein the winding density is 0.15 m / cm 2 More than 0.60m / cm 2 It is characterized by the following:

[0025] (16) The sixteenth aspect of the present invention is the kitchen towel roll according to (1) or (2), characterized in that the paper towel has a linear embossed pattern. [Effects of the Invention]

[0026] According to the present invention, it is possible to provide a kitchen towel roll that is excellent in water absorption and softness even when it is long, is easy to mount on a paper holder, and further, when mounted on the paper holder, the perforations can be easily cut from the beginning to the end of use of the roll. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a perspective view of a kitchen towel roll according to an embodiment of the present invention. [Figure 2] FIG. 10 is a plan view showing an example of a sheet obtained by cutting a paper towel along perforations. [Figure 3] FIG. 1 is a diagram showing an example of an embossed pattern on a paper towel. [Figure 4]FIG. 1 is a diagram showing a method for measuring the water absorption of a paper towel. [Figure 5] FIG. 10 is a diagram showing the height profile of a non-embossed portion on the XY plane as viewed under a microscope, using shading. [Figure 6] FIG. [Figure 7] FIG. 1 is a diagram showing a part of a paper towel manufacturing process. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, one embodiment of the present invention will be described in detail. However, the following embodiment is presented for illustrative purposes, and the present invention is not limited to the embodiment shown below.

[0029] In this specification, the term "kitchen towel roll" (hereinafter simply referred to as "roll") refers to a roll product in which paper towels are wound into a roll. The term "sheet" refers to a sheet-like product in which paper towels are pulled out from a kitchen towel roll and cut along the perforations.

[0030] "MD direction" refers to the direction in which the paper towel runs through the machine, and "CD direction" refers to the direction perpendicular to the MD direction. In this specification, "MD direction of the roll product" refers to the direction in which the paper towel is wound (Y direction in Figure 1), and "CD direction of the roll product" refers to the direction perpendicular to the direction in which the paper towel is wound (X direction in Figure 1). "Axial direction" refers to the axial direction of the roll product, which is the CD direction of the roll product (X direction in Figure 1).

[0031] In this specification, the term "product ply" refers to a paper towel in which the number of plies is in a product state, without peeling off the stacked plies into a single sheet.

[0032] <Kitchen towel roll> As shown in FIG. 1, the kitchen towel roll 1 of the present invention is a paper towel 1x having perforations 1c wound into a roll.

[0033] The kitchen towel roll 1 can be used, for example, as a roll of kitchen paper (sometimes called paper towel or cooking paper) used in home kitchens and restaurant kitchens to wipe away moisture or oil and remove dirt, as well as other rolls of sanitary paper.

[0034] The details of each component are as follows:

[0035] <Paper towels> Paper towel 1x can be made by going through a papermaking process, stacking base papers, embossing as needed, and then winding them into a roll to form roll 1. Alternatively, the base papers may be embossed before being stacked and wound into roll 1.

[0036] The paper towel 1x is preferably produced by a TAD (through-air drying) papermaking method, which is a method in which, in the dehydration and drying step of the papermaking process, air drying is performed (it is preferable not to press-dry the wet paper), and by producing the paper towel 1x by the TAD papermaking method, it is possible to obtain a bulky, soft paper towel 1x with excellent water absorbency.

[0037] (raw materials) The paper towel 1x may contain pulp fibers.

[0038] Common pulp fibers such as softwood bleached kraft pulp (NBKP) and hardwood bleached kraft pulp (LBKP) can be used as the pulp fibers. The NBKP and LBKP content ratio in the pulp fibers is preferably NBKP:LBKP = 40-100% by mass:60-0% by mass, more preferably NBKP:LBKP = 50-90% by mass:50-10% by mass, and even more preferably NBKP:LBKP = 60-80% by mass:40-20% by mass. If the NBKP content ratio is less than the above-mentioned lower limit, the perforations tend to tear unintentionally. If the NBKP content ratio exceeds the above-mentioned upper limit, the softness of the sheet deteriorates. If the LBKP content ratio is less than the above-mentioned lower limit, the softness of the sheet deteriorates, and if it exceeds the above-mentioned upper limit, the perforations tend to tear unintentionally.

[0039] The proportion (content) of wet pulp fiber in the paper towel 1x is preferably 50% or more, more preferably 70% or more, and even more preferably 90% or more. If the proportion of wet pulp fiber is 50% or more, the perforation 1c will not be accidentally torn and the paper towel 1x will have good water absorbency.

[0040] (Uneven pattern resulting from the papermaking process) The surface of the paper towel 1x preferably has an uneven pattern 11 resulting from the papermaking process, as shown in Figure 2. By having the uneven pattern 11 resulting from the papermaking process, the water absorbency of the paper towel 1x is improved.

[0041] (embossed pattern) The paper towel 1x preferably has an embossed pattern 12 as shown in Figures 2 and 3, and more preferably has a linear embossed pattern 12a. The embossed pattern 12 improves the aesthetic appeal of the roll 1, and the linear embossed pattern 12a prevents the inter-fiber bonds of the paper towel 1x from breaking, making the perforations 1c less likely to break unintentionally. Note that "linear" refers to an embossed pattern having a thickness of 0.1 mm to 4 mm and a length of 5 mm or more.

[0042] (Number of plies) The number of plies in a paper towel 1x is preferably 2 or 3, with 2 being more preferable. A single ply results in poor absorbency due to the lack of inter-ply voids. A four-ply or higher ply results in a thicker paper towel, which can lead to poor sheet softness and a larger roll diameter, making it difficult to attach to a paper holder. Furthermore, thicker paper results in stronger perforations, making it difficult to cut.

[0043] (paper thickness) The paper thickness per 10 plies of paper towel 1x (hereinafter simply referred to as "paper thickness") is preferably 2.2 mm or more and 5.3 mm or less. If the paper thickness of paper towel 1x is less than 2.2 mm, the absorbency of paper towel 1x will be poor, and if it exceeds 5.3 mm, the softness of paper towel 1x will be poor. The lower limit of paper thickness is more preferably 2.5 mm or more, and even more preferably 2.8 mm or more. The upper limit is more preferably 4.5 mm or less, and even more preferably 3.7 mm or less.

[0044] Paper thickness is measured using the following method. A thickness gauge (Ozaki Seisakusho Co., Ltd., "PEACOCK" dial thickness gauge) is used. The measurement conditions are a measurement load of 3.7 kPa and a probe diameter of 30 mm. The sample is placed between the probe and the measuring table, and the gauge is read when the probe is lowered at a speed of 1 mm per second or less. To measure the thickness of a 10-ply sheet, 10 plies (5 sets of 2-ply sheets) are stacked and measured 10 times, and the results are averaged. For a 3-ply sheet, 9 plies (3 sets of 3-ply sheets) are stacked and measured, and the thickness of one ply is calculated from the measurement results and converted to 10 plies. Paper thickness is measured at 10 points: five different points in the MD (Y direction in Figure 1) of the sheet, and five points shifted from these five points in the CD (X direction in Figure 1). It is important to measure the paper thickness at 10 different points, but the exact position is not important.

[0045] (Basic weight) The basis weight of the product ply for one paper towel is 33 g / m 2More than 65g / m 2 The preferred basis weight is 33 g / m 2 If it is less than 65g / m, the absorbency of one paper towel will be poor. 2 If the paper towel exceeds this limit, the softness of the paper towel will be reduced. The lower limit of the basis weight is 37 g / m 2 More preferably, 42 g / m 2 More preferably, the upper limit is 53 g / m 2 Less than 48g / m is more preferable. 2 The following is more preferable: The basis weight is measured in accordance with JIS P 8124.

[0046] (specific volume) The specific volume of one paper towel is 8.0 cm 3 / g or more 23.0cm 3 / g or less. The specific volume of 1x paper towel is 8.0 cm 3 If the absorbency is less than 23.0 cm / g, the absorbency of one paper towel is poor. 3 If the specific volume exceeds 10.0 cm3 / g, the softness of the paper towel 1x will be poor. 3 / g or more is more preferable, and 11.5cm 3 The upper limit is preferably 20.0 cm / g or more. 3 / g or less is more preferable, and 17.0cm 3 The specific volume is calculated by dividing the paper thickness of a predetermined number of plies (for example, product plies) of paper towel 1x by the basis weight of the predetermined number of plies, and then expressing the volume cm per unit g. 3 It is expressed as:

[0047] (Water absorption <unit area>) The water absorption per unit area of ​​1 paper towel (hereinafter referred to as "water absorption <unit area>") is 320 g / m 2 More than 600g / m 2 Water absorption <unit area> is 320g / m or less. 2 If it is less than 600g / m, the absorbency of one paper towel will be poor. 2 If the water absorption capacity exceeds 370g / m², the softness of the paper towel will be reduced. 2More than 420 g / m 2 More preferably, the upper limit is 570 g / m 2 Preferably less than 530 g / m 2 The following is even more preferred:

[0048] (Water absorption <unit mass>) The water absorption per unit mass of 1x paper towel (hereinafter also referred to as "water absorption <unit mass>") is preferably 8.0 g / g or more and 13.5 g / g or less. If the water absorption <unit mass> is less than 8.0 g / g, the water absorbency of 1x paper towel will be poor, and if it exceeds 13.5 g / g, the softness of 1x paper towel will be poor. The lower limit of the water absorption <unit mass> is more preferably 8.5 g / g or more, and even more preferably 9.0 g / g or more. The upper limit is more preferably 12.5 g / g or less, and even more preferably 11.3 g / g or less.

[0049] The water absorption capacity of 1 paper towel is measured according to the following method. (1) Two plies of paper towel are taken and cut using a square template with one piece measuring 76 mm to prepare a rectangular test piece 20 (see FIG. 4) with one side measuring 76 mm. (2) The mass of the test piece 20 before water absorption is measured using an electronic balance. (3) The test piece 20 is set in a holder 22 (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 220 is immersed in the distilled water for 2 minutes. (5) Remove the test piece 20 together with the holder 22 from the distilled water, hang the holder 22 and test piece 20 on a rod placed in an empty water tank with the corner 20a facing up, close the lid of the water tank, and leave for 5 minutes. (6) The holder 22 and the test piece 20 are removed from the water tank, the holder 22 is removed, and the mass of the test piece 20 is measured using an electronic balance.

[0050] Measurements are taken five times for each sample, and the average value is used. When the paper towel 1x is three-ply, it is preferable to measure it as a three-ply towel using the same procedure as for two-ply towels. This measurement is performed according to JIS P 8111 at a temperature of 23±1°C and humidity of 50±2%. The distilled water is kept at 23±1°C.

[0051] (Calculation of water absorption <unit area>) The water absorption amount <unit area> was calculated from the change in mass of the test piece 20 before and after immersion in distilled water, and was calculated as the amount of distilled water absorbed per unit area of ​​the test piece 20 (water g / sheet m 2 , 1m 2 Per. Abbreviated as g / m 2 (See formula (1) below.) Water absorption amount <unit area> = (change in mass of test piece 20) ÷ (area of ​​test piece 20) (1)

[0052] (Calculation of water absorption <unit mass>) Water absorption capacity (unit mass) is calculated by multiplying the water absorption capacity (unit area) by g of water / sheet m 2 ) is divided by the basis weight of the product ply of the test piece 20 to calculate the water absorption <unit mass> (g of water / g of sheet, per 1g, abbreviated as g / g) (see formula (2) below). Water absorption amount <unit mass> = (water absorption amount <unit area>) ÷ (basis weight of product ply) (2)

[0053] (surface roughness) The root mean square height of the surface roughness of the paper towel 1x (hereinafter simply referred to as "surface roughness" or "Sq") is 35 μm or more and 170 μm or less. If the surface roughness is less than 35 μm, the water absorbency of the paper towel 1x will be poor, and if it exceeds 170 μm, the inter-fiber bonds of the paper towel 1x will break, making the perforations 1c more likely to break unintentionally. The lower limit of the surface roughness is preferably 50 μm or more, more preferably 60 μm or more. The upper limit is preferably 150 μm or less, more preferably 100 μm or less.

[0054] The root mean square height Sq of the surface roughness of the paper towel 1x is measured using a microscope. The microscope used can be a Keyence One-Shot 3D Measuring Macroscope VR-3100. The software used for observing, measuring, and analyzing microscope images can be a Keyence Analysis Application VR-H1A. The measurement conditions are a magnification of 38x and a field of view of 8mm x 6mm. The measurement magnification and field of view may be changed as appropriate depending on the area being measured. If the paper towel 1x has an embossed pattern 12, the area without the embossed pattern 12 is measured.

[0055] Filters are set for the obtained image (Figure 5). Specifically, by setting an S-filter (low-pass filter), components with a scale smaller than the cutoff wavelength are removed from the image. By setting an L-filter (high-pass filter), components with a scale larger than the cutoff wavelength are removed from the image. Here, the S-filter is set to 500 μm and the L-filter to 8 mm. By selecting the S-filter and L-filter, the root mean square height Sq is automatically calculated.

[0056] The sample to be measured is prepared by removing three wraps of paper towels 1x from kitchen towel roll 1, cutting one sheet from the fourth wrap of paper towels 1x, and measuring the surface side of the product ply sheet. If there are perforations 1c or embossed patterns 12, these are avoided during the measurement. Three locations are measured in the MD direction of sheet 10 (Y direction in Figure 2), and for each location measured in the MD direction, three different locations are measured in the CD direction (X direction in Figure 2). The average value of the six locations is then used as the root mean square height Sq.

[0057] (DMDT) The dry machine direction tensile strength (DMDT) of the portion of the paper towel 1x not including the perforation 1c is preferably 2100 cN / 75 mm or more and 4500 cN / 75 mm or less. If the DMDT is less than 2100 cN / 75 mm, the DMDT of the portion including the perforation 1c will also be low, resulting in unintentional tearing of the perforation 1c. If the DMDT exceeds 4500 cN / 75 mm, the softness of the paper towel 1x will be reduced, and the DMDT of the portion including the perforation 1c will also be high, making it difficult to tear the perforation 1c. The lower limit of the DMDT is more preferably 2600 cN / 75 mm or more, and even more preferably 2900 cN / 75 mm or more. The upper limit is more preferably 4200 cN / 75 mm or less, and even more preferably 3700 cN / 75 mm or less. DMDT is measured based on JIS P 8113, and the sample used does not contain perforation 1c.

[0058] (DCDT) The dry cross direction tensile strength (DCDT) of the portion of the paper towel 1x not including the perforation 1c is preferably 2100 cN / 75 mm or more, more preferably 2600 cN / 75 mm or more, and even more preferably 2900 cN / 75 mm or more. The upper limit is preferably 4500 cN / 75 mm or less, more preferably 4200 cN / 75 mm or less, and even more preferably 3700 cN / 75 mm or less. If the DCDT is less than 2100 cN / 75 mm, the DCDT of the portion including the perforation 1c will be low, resulting in unintentional tearing of the perforation 1c. If the DCDT exceeds 4500 cN / 75 mm, the softness of the paper towel 1x will be poor, and the DCDT of the portion including the perforation 1c will be high, making it difficult to tear the perforation 1c. DCDT is measured based on JIS P 8113, and the sample used does not include perforation 1c.

[0059] (DGMT) The DGMT (Dry Geometric Tensile Strength) of the paper towel 1x in the portion not including the perforation 1c is preferably 2100 cN / 75 mm or more, more preferably 2600 cN / 75 mm or more, and even more preferably 2900 cN / 75 mm or more. The upper limit is preferably 4500 cN / 75 mm or less, more preferably 4200 cN / 75 mm or less, and even more preferably 3700 cN / 75 mm or less. If the DGMT is less than 2100 cN / 75 mm, the DGMT of the portion including the perforation 1c will be low, resulting in the perforation 1c being unintentionally torn. If the DGMT is more than 4500 cN / 75 mm, the softness of the paper towel 1x will be poor, and the DGMT of the portion including the perforation 1c will be high, making it difficult to tear the perforation 1c.

[0060] DGMT can be calculated by taking the geometric mean of DMDT and DCDT (see formula (3) below). DGMT = (DMDT × DCDT) 1 / 2 ···(3)

[0061] (perforation) The paper towel 1x has perforations 1c spaced at regular intervals in the MD direction and extending generally parallel to the CD direction to allow the sheet 10 to be cut into a size suitable for use. The perforations 1c are formed by alternating succession of cut portions 15a and connecting portions 15b, as shown in Figure 6. The arrangement of the cut portions 15a and connecting portions 15b in the perforations 1c may be curved, but is preferably linear.

[0062] (Length of cut part) The length (L1) of one cut portion (hereinafter also referred to simply as "notch") 15a of the perforation 1c is preferably 2.0 mm or more and 7.0 mm or less. If the cut portion 15a is less than 2.0 mm, it will be difficult to cut the perforation 1c, and if it exceeds 7.0 mm, it will be easy to unintentionally cut the perforation 1c. The lower limit of the length of the cut portion 15a is more preferably 3.0 mm or more. The upper limit is more preferably 6.0 mm or less, and even more preferably 5.0 mm or less.

[0063] (Length of joint) The length (L2) of each connecting portion 15b of perforation 1c (hereinafter also referred to simply as "non-cut portion") is preferably 0.5 mm or more and 2.0 mm or less. If connecting portion 15b is less than 0.5 mm, perforation 1c is likely to be torn unintentionally, and if it exceeds 2.0 mm, perforation 1c is difficult to tear. The upper limit of the length of connecting portion 15b is more preferably 1.5 mm or less, and even more preferably 1.0 mm or less.

[0064] (Perforation bond rate) The bond ratio of the perforation 1c is preferably 10% or more and 30% or less. If the bond ratio of the perforation 1c is less than 10%, the perforation 1c may be torn unintentionally, and if it exceeds 30%, the perforation 1c may be difficult to torn. The lower limit of the bond ratio of the perforation 1c is more preferably 12% or more, and even more preferably 15% or more. The upper limit is more preferably 28% or less, and even more preferably 25% or less.

[0065] The bond ratio of the perforation 1c is calculated as follows: First, the total length of the cut portion 15a (the sum of L1) and the total length of the connecting portion 15b (the sum of L2) are calculated, and the sum is designated as L3. Then, the bond ratio is calculated by dividing the sum of L2 by L3 (see formula (4)). Perforation bond ratio = (sum of L2) ÷ (L3) × 100 (4)

[0066] (Perforated DMDT) The tensile strength of the perforation 1c (hereinafter also referred to as "perforation DMDT") is 405 cN / 75 mm or more and 1470 cN / 75 mm or less. If the perforation DMDT is less than 405 cN / 75 mm, the perforation 1c is likely to tear unintentionally, and if it exceeds 1470 cN / 75 mm, the perforation 1c is difficult to tear. The lower limit of the perforation DMDT is preferably 505 cN / 75 mm or more, and more preferably 555 cN / 75 mm or more. The upper limit is preferably 1250 cN / 75 mm or less, and even more preferably 1050 cN / 75 mm or less. The perforation DMDT corresponds to the so-called perforation strength.

[0067] The perforation DMDT can be measured, for example, using a single-column material testing machine STB-1225S (manufactured by A&D Co., Ltd.) according to a method in accordance with JIS P 8113. The width dimension of the test piece (the direction perpendicular to the tensile direction of the single-column material testing machine) is 75 mm, the distance between the grippers is 100 mm, the tensile speed is 300 mm / min, the measurement temperature is 23°C, the relative humidity is 50%, and the tensile direction is perpendicular to the perforation 1c. The tensile strength is measured multiple times (for example, four times), and the average value is taken as the perforation DMDT.

[0068] (Perforated DMDT / DMDT) The ratio of "perforated DMDT" to "DMDT" in paper towel 1x (=perforated DMDT / DMDT) is preferably 0.14 or more and 0.44 or less. If this ratio is less than 0.14, perforation 1c becomes more likely to tear unintentionally, and if it exceeds 0.44, perforation 1c becomes more difficult to tear. The lower limit of this ratio is more preferably 0.16 or more, and even more preferably 0.24 or more. The upper limit is more preferably 0.36 or less, and even more preferably 0.30 or less.

[0069] (Perforation DMDT / Roll weight <without core>) The ratio of "perforation DMDT" to "roll mass (without core)" (described later) (= perforation DMDT / roll mass (without core)) is preferably 1.1 or more and 4.0 or less. If this ratio is less than 1.0, the perforation 1c is likely to tear unintentionally, and if it exceeds 4.0, the perforation 1c is difficult to tear. The lower limit of this ratio is more preferably 1.4 or more, and even more preferably 1.6 or more. The upper limit is more preferably 3.4 or less, and even more preferably 2.5 or less.

[0070] <Kitchen towel roll> As shown in FIG. 1, the kitchen towel roll 1 of this embodiment is a paper towel 1x wound into a roll, and has a core 1d in the center, such as a cylindrical paper core or a cylindrical space, with the outer diameter (winding diameter) of the roll 1 being DR and the outer diameter of the core 1d being DI.

[0071] (core) The core 1d is located at the center of the roll 1. The core 1d may be a cylindrical paper tube or a cylindrical space. In this embodiment, the core 1d of the roll 1 has a cylindrical paper tube made of multiple layers of base paper, and the paper towel 1x is wound around this paper tube. In the following description, the core 1d refers to the core 1d that is a cylindrical paper tube unless otherwise specified.

[0072] The core 1d preferably contains BKP (Bleached Kraft Pulp) as the pulp fiber contained in the base paper. The BKP content is preferably 50% by mass or more, more preferably 70% by mass or more, and even more preferably 90% by mass or more. If the BKP content is 50% by mass or more, the core 1d is less likely to be crushed and is easier to attach to a paper holder.

[0073] The BKP contained in the core 1d preferably includes LBKP. The LBKP content is preferably 50% or more, more preferably 70% or more, and even more preferably 90% or more, based on 100% by mass of BKP. If the LBKP content is 50% or more by mass, the cost of the core 1d can be reduced.

[0074] (Core outer diameter) The outer diameter of the core 1d (DI in Figure 1) (hereinafter simply referred to as "core outer diameter") is preferably 20 mm or more and 60 mm or less. If the core outer diameter is less than 20 mm, it becomes difficult to attach the roll 1 to a paper holder, and if it exceeds 60 mm, the winding diameter of the roll 1 becomes large, making it difficult to attach it to a paper holder. The lower limit of the core outer diameter is more preferably 30 mm or more, and even more preferably 38 mm or more. The upper limit is more preferably 55 mm or less, and even more preferably 50 mm or less.

[0075] The core outer diameter is measured, for example, using a diameter rule (manufactured by Muratec KDS Co., Ltd.). Three rolls 1 are measured and the measurement results are averaged. If there is no core, the diameter of the cylindrical space (center hole) at the center of the roll 1 is considered to be the core outer diameter.

[0076] (core mass) The mass of the core 1d (hereinafter simply referred to as "core mass") is preferably 10 g or more and 25 g or less. If the core mass is less than 10 g, the diameter of the core 1d becomes small, making it difficult to attach to a paper holder. If the core mass exceeds 25 g, the core becomes too large when rolled, increasing the winding diameter and making it difficult to attach to a paper holder. The lower limit of the core mass is more preferably 12 g or more, and even more preferably 14 g or more. The upper limit is more preferably 20 g or less, and even more preferably 17 g or less.

[0077] The core mass is the mass per 280 mm of roll width W. If the roll width W is not 280 mm, it is converted to the mass per 280 mm by proportional calculation. The roll width W means the length of the roll 1 in the axial direction (see Figure 1).

[0078] (Reel diameter (DR)) The winding diameter (DR in Figure 1) of the roll 1 (hereinafter simply referred to as "winding diameter") is 125 mm or more and 175 mm or less. If the winding diameter DR is less than 125 mm, the roll 1 cannot be made long, and if it exceeds 175 mm, it becomes difficult to attach the roll 1 to a paper holder. The lower limit of the winding diameter is preferably 135 mm or more, and more preferably 142 mm or more. The upper limit is preferably 165 mm or less, and more preferably 156 mm or less. The winding diameter is measured using a diameter rule manufactured by Muratec KDS Co., Ltd. Three rolls 1 are measured and the measurement results are averaged.

[0079] (Volume length) The winding length of the roll 1 (hereinafter simply referred to as "winding length") is preferably 18 m or more and 50 m or less. If the winding length is less than 18 m, the roll 1 cannot be made long, and if it exceeds 50 m, it becomes difficult to attach the roll 1 to a paper holder. The lower limit of the winding length is more preferably 22 m or more, and even more preferably 27 m or more. The upper limit is more preferably 40 m or less, and even more preferably 31 m or less.

[0080] The roll length can be measured using the following method. The "length between perforations 1c" of 1x paper towel is taken as the length of one sheet, and the "length of 10 sheets" is measured. Next, the "number of sheets" of 1x paper towel in roll 1 is measured, and the length is calculated proportionally from this "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 the result is 1.80m x (150 ÷ ​​10) = 27m.

[0081] (seat length) The lower limit of the length between perforations 1c of roll 1 (hereinafter simply referred to as "sheet length") is preferably 100mm or more, more preferably 120mm or more, and even more preferably 140mm or more. The upper limit is preferably 300mm or less, more preferably 250mm or less, and even more preferably 220mm or less. If the sheet length is less than 100mm, the sheet size becomes small, resulting in poor absorbency and difficulty in use. If it exceeds 300mm, the sheet size becomes large, increasing the amount used and making it difficult to use. Note that "sheet length" means the length in the MD direction of roll 1.

[0082] (Sheet width (W)) The lower limit of the roll width (W in FIG. 1) of the roll 1 (hereinafter also simply referred to as "sheet width") is preferably 200 mm or more, more preferably 220 mm or more, and even more preferably 260 mm or more. The upper limit of the roll width is preferably 320 mm or less, more preferably 310 mm or less, and even more preferably 290 mm or less. If the roll width is less than 200 mm, the sheet size becomes small, resulting in poor absorbency and difficulty in use. If it exceeds 320 mm, the sheet size becomes large, increasing the amount used and making it difficult to use. Note that "roll width" refers to the length in the axial direction of the roll 1.

[0083] (winding density) The winding density of the roll 1 (hereinafter simply referred to as "winding density") is 0.15 m / cm 2 More than 0.60m / cm 2 The winding density is preferably 0.15 m / cm or less. 2If the winding density is less than 0.60 m / cm, the roll 1 will be wound loosely, resulting in a large diameter, making it difficult to attach to the paper holder. 2 If the density exceeds 0.20m / cm, the basis weight will be low and the absorbency of the paper towel will be poor. 2 More preferably, 0.30 m / cm or more 2 The upper limit is preferably 0.50 m / cm. 2 Less than 0.40m / cm is more preferable. 2 The following is even more preferred:

[0084] The winding density can be calculated using the following formula (5). For example, in the case of a winding length of 20 m, 2 plies, a winding diameter (DR) of 154 mm, and a core outer diameter (DI) of 44 mm, the winding density is (20 m × 2) ÷ {3.14 × (154 mm ÷ 2 ÷ 10} 2 -3.14×(44mm÷2÷10) 2}=0.23m / cm 2 This becomes: Winding density = (winding length × number of plies) ÷ (cross-sectional area of ​​roll 1) (5) Cross-sectional area of ​​roll 1 = (cross-sectional area of ​​winding diameter part) - (cross-sectional area of ​​core outer diameter part) (6)

[0085] (Roll mass <without core>) The roll mass of the roll 1 without the core 1d per 280 mm of roll width (hereinafter simply referred to as "roll mass <without core>") is preferably 190 g or more and 620 g or less. If the roll mass <without core> is less than 190 g, the basis weight and thickness will be low, and the absorbency of the paper towel 1x will be poor. In addition, the roll 1 will not be long. If the roll mass <without core> exceeds 620 g, the softness of the paper towel 1x will be poor and it will be difficult to attach to a paper holder. The lower limit of the roll mass <without core> is more preferably 280 g or more, and even more preferably 320 g or more. The upper limit is more preferably 450 g or less, and even more preferably 420 g or less.

[0086] (roll density) The roll density of roll 1 (hereinafter simply referred to as "roll density") is 0.03 g / cm 3More than 0.20g / cm 3 The roll density is preferably 0.03 g / cm or less. 3 If it is less than 0.20 g / cm, the diameter of roll 1 will be too large and it will be difficult to attach it to the paper holder. 3 If the density exceeds 0.06g / cm, the softness of the paper towel will be reduced. 3 More preferably, 0.07 g / cm or more 3 The upper limit is 0.10 g / cm. 3 Less than 0.09 g / cm is more preferable. 3 The following is even more preferred:

[0087] The roll density can be calculated by (roll mass (without core)) ÷ (volume of roll 1), and is obtained from the following formula (7). For example, if the roll mass (without core) is 237 g, the winding diameter is 154 mm, and the core outer diameter is 44 mm, the roll density = 237 g ÷ {(3.14 × (154 mm ÷ 2 ÷ 10)} 2 -3.14×(44mm÷2÷10) 2 )×(280mm÷10)}=0.05g / cm 3 The roll width is calculated based on 280 mm. Roll density = Roll mass <without core> ÷ [{(cross-sectional area of ​​winding diameter) - (cross-sectional area of ​​core outer diameter)} × roll width] (7)

[0088] (Manufacturing methods for paper towels and roll products) The paper towel 1x and roll 1 according to this embodiment can be manufactured, for example, in the following order: (1) papermaking and creping, (2) embossing and adhesive treatment, and (3) roll winding. Note that, in the manufacturing (papermaking) process of the paper towel 1x, it is preferable to use TAD papermaking technology.

[0089] In the papermaking process (1), it is preferable that a concave-convex pattern 11 derived from the papermaking process (fabric), which is different from the above-mentioned embossed pattern, is applied to the paper towel 1x. By having this concave-convex pattern 11, the water absorption capacity of the paper towel 1x can be further increased.

[0090] "Derived from the papermaking process" means that the uneven pattern 11 is imparted between the head box 41 of the papermaking machine and the outlet of the Yankee dryer 46 during the papermaking process of the paper towel 1x. Specifically, in a portion of the papermaking process shown in FIG. 7, pulp slurry 40a is sprayed (supplied) from the head box 41 between the first fabric (forming fabric) 42 and the second fabric (uneven fabric) 43, and is drawn onto the second fabric (uneven fabric) 43 by the forming roll 44, forming a wet paper 40b. Next, the wet paper 40b is dried together with the second fabric (uneven fabric) 43 in a through-air dryer 45, resulting in the formation of unevenness in the dried sheet 40c. Note that while FIG. 7 shows two through-air dryers 45, a single unit may be used. Also, although a Yankee hood is depicted on the Yankee dryer 46, the hood may be omitted. Crepe may be imparted in the Yankee dryer 46.

[0091] Although the present invention has been described above based on the above embodiment, the present invention is not limited to the content of the above embodiment and can be modified as appropriate without departing from the scope of the present invention. In other words, all other embodiments, examples, operational techniques, etc. made by those skilled in the art based on this embodiment are naturally included in the scope of the present invention. [Example]

[0092] The present embodiment will be described in more detail below with reference to examples and comparative examples, but the present invention is not limited to the following examples.

[0093] (Examples 1 to 13, Comparative Examples 1 to 6) For Examples 1 to 13 and Comparative Examples 1 to 6, kitchen towel rolls were produced using the above-mentioned production methods under the conditions shown in Tables 1 and 2. Then, the following four evaluations were carried out for each kitchen towel roll.

[0094] 1.Water absorption A sensory evaluation of the absorbency of the manufactured paper towels when wiping away moisture was conducted by 20 panelists. Each panelist removed three wraps of paper towels from a kitchen towel roll, cut a sheet (280mm x 180mm) from the fourth wrap, and used it to wipe away 40cc of water that had been sprinkled on a table. They then selected "good absorbency" or "poor absorbency" and evaluated the results according to the following criteria: ◎: "Good absorbency" - 18 or more people ○: "Good absorbency": 15 to 17 people △: "Good absorbency": 12 to 14 people ×: "Good absorbency": 0 to 11 people

[0095] 2. Softness A sensory evaluation of the "softness" of paper towels after production was conducted by 20 panelists. Each panelist removed three wraps of paper towels from a kitchen towel roll, cut one sheet from the fourth wrap, and selected "the sheet is soft" or "the sheet is hard," and rated according to the following criteria. ◎: 18 or more people said "The seat is soft" ○: "The seat is soft" - 15 to 17 people △: "The seat is soft" - 12 to 14 people ×: "The seat is soft" - 0 to 11 people

[0096] 3.Easy to attach to paper holder A sensory evaluation was conducted by 20 panelists on the "ease of attaching" kitchen towel rolls to paper holders after manufacturing. Each panelist attached a kitchen towel roll to a paper holder set on the side of a shelf and selected "easy to attach" or "difficult to attach," and rated the rolls according to the following criteria: ◎: More than 18 people said it was "easy to wear" ○: "Easy to wear": 15 to 17 people △: "Easy to wear": 12 to 14 people ×: "Easy to wear": 0 to 11 people

[0097] 4. Perforation cutting balance After manufacturing, kitchen towel rolls were attached to a paper holder, and a sensory evaluation of the "perforation cutting balance" when cutting the paper towels was conducted by 20 panelists. Each panelist pulled out one sheet of paper towels from the kitchen towel roll attached to the paper holder and cut it by hand. The cutting was evaluated at three locations: the second sheet at the beginning of use, the sheet 15 m after use, and the sheet at the end of use. The panelists selected either "the perforations were not accidentally torn at all three locations, and the paper towels were cut with a moderate amount of force without tearing anywhere other than the perforations" or "the perforations were accidentally torn, the paper towels were broken anywhere other than the perforations, or more force than necessary was required to cut at any location," and the evaluation was based on the following criteria. ◎: "The perforations did not tear unintentionally in all three places, and the product did not break anywhere other than the perforations, and it was able to be cut with just the right amount of force" - 18 or more people ○: "The perforations did not tear unintentionally in all three places, and the product did not break anywhere other than the perforations, and it was able to be cut with just the right amount of force" - 15 to 17 people △: "The perforations did not tear unintentionally in all three places, and the film was able to be cut with moderate force without breaking anywhere other than the perforations" - 12 to 14 people ×: "The perforations did not tear unintentionally in all three places, and the product was able to be cut with moderate force without breaking anywhere other than the perforations" - 0 to 11 people

[0098] The results obtained are shown in Tables 1 and 2.

[0099] [Table 1]

[0100] [Table 2]

[0101] As is clear from the results shown in Tables 1 and 2, the kitchen towel rolls of Examples 1 to 13 were all excellent in absorbency, softness, ease of attachment to a paper holder, and perforation cut balance. In contrast, the rolls of Comparative Examples 1 to 6 were inferior in any of absorbency, softness, ease of attachment to a paper holder, and perforation cut balance.

[0102] From the above, according to the present disclosure, it has been confirmed that even long kitchen towel rolls have excellent water absorption and softness, are easy to attach to paper holders, and furthermore, when attached to a paper holder, it is easy to cut the perforations from the beginning to the end of the roll. [Explanation of symbols]

[0103] 1: Kitchen towel roll (roll) 1c: Perforation 1d: Core 1x: Paper towel 10: Sheet 11: Concave and convex pattern derived from the papermaking process 12: Embossed pattern 12a: Linear embossing 15a: (perforation) cut section 15b: (Perforation) Joint 20: Test piece 21: Holder 40a: Pulp slurry 40b: Wet paper 40c: dry sheet 41: Head box 42: First fabric (forming fabric) 43: Second fabric (textured fabric) 44: Forming roll 45:Through air dryer 46: Yankee Dryer

Claims

1. A kitchen towel roll in which paper towels with axial perforations are wound into a roll, The paper towel has a water absorption capacity of 320 g / m ２ More than 600g / m ２ The root mean square height of the surface roughness is 35 μm or more and 170 μm or less, The tensile strength in the MD direction of the perforation when the paper towel is dry (perforation DMDT) is 405 cN / 75 mm or more and 1470 cN / 75 mm or less; The winding length is 18 m or more and 50 m or less, and the winding diameter is 125 mm or more and 175 mm or less. A kitchen towel roll.

2. 2. The kitchen towel roll of claim 1, wherein the paper towel has a bond rate (perforation bond ratio) of 10% or more and 30% or less (length of the joint of the perforation ÷ (length of the cut portion of the perforation + length of the joint of the perforation) × 100.

3. 3. The kitchen towel roll according to claim 1, wherein the paper towel has an uneven pattern on the surface thereof resulting from the papermaking process.

4. 3. The kitchen towel roll according to claim 1, wherein the paper towel is wound around a core, and the roll mass per 280 mm of the roll width excluding the core is 190 g or more and 620 g or less.

5. 3. The kitchen towel roll according to claim 1, wherein the length of the joint of the perforations is 0.5 mm or more and 2.0 mm or less.

6. 3. The kitchen towel roll according to claim 1, wherein the length of the cut portion of the perforation is 2.0 mm or more and 7.0 mm or less.

7. 3. The kitchen towel roll of claim 1, wherein the MD tensile strength (DMDT) of the portion of the paper towel not including the perforations when dry is 2100 cN / 75 mm or more and 4500 cN / 75 mm or less.

8. 8. The kitchen towel roll of claim 7, wherein the ratio of the perforation DMDT to the DMDT is greater than or equal to 0.14 and less than or equal to 0.

44.

9. 5. The kitchen towel roll of claim 4, wherein the ratio of the perforations DMDT to the roll mass is 1.1 or more and 4.0 or less.

10. The basis weight of the paper towel product ply is 33 g / m ２ 65g / m or more ２ 3. The kitchen towel roll according to claim 1 or 2, characterized in that:

11. 3. The kitchen towel roll according to claim 1, wherein the paper thickness per 10 plies of the paper towel is 2.2 mm or more and 5.3 mm or less.

12. The specific volume of the paper towel is 8.0 cm ３ / g or more 23.0cm ３ 3. The kitchen towel roll according to claim 1, wherein the kinematic viscosity is 1 / g or less.

13. 3. The kitchen towel roll according to claim 1, wherein the water absorption per unit mass of the paper towel is 8.0 g / g or more and 13.5 g / g or less.

14. Roll density is 0.03 g / cm ３ 0.20g / cm or more ３ 3. The kitchen towel roll according to claim 1 or 2, characterized in that:

15. Winding density: 0.15 m / cm ２ 0.60m / cm or more ２ 3. The kitchen towel roll according to claim 1, wherein:

16. 3. The kitchen towel roll of claim 1, wherein the paper towel has a linear embossed pattern.

Images