Paper towel packaging

Abstract

The present invention provides a paper towel packaging that reduces drop-back during dispensing without lowering the basis weight of the paper towel sheets, while also maintaining good texture and absorbency. [Solution] A paper towel package comprising two-ply or three-ply paper towel sheets having an uneven pattern derived from the papermaking process, different from an embossed pattern, laminated in a pop-up manner and film-wrapped, wherein the basis weight per ply of the paper towel sheet is 14 g / m². 2 More than 30g / m 2 The present invention provides a paper towel packaging characterized by having a sheet length of 130 mm or more and 370 mm or less, a root mean square height of surface roughness in areas without an embossed pattern of 25 μm or more and 130 μm or less, and a film thickness of 20 μm or more and 90 μm or less.

Description

[Technical Field]

[0001] This invention relates to a paper towel packaging. [Background technology]

[0002] Currently, various paper and non-woven towel products, such as paper towels and kitchen towels, are available on the market, but among them, products with a high-quality, premium feel are attracting attention.

[0003] High-quality paper towels often require specific qualities such as texture and tear resistance. Among these, paper towel sheets produced using the so-called TAD (Through Air Dryer, also known as Through Air Drying) papermaking technology, which utilizes air-drying, are thicker, have a softer texture, and offer superior water absorption.

[0004] Generally, paper towels, such as kitchen paper, are often sold in rolls that fit into holders. However, there is also a demand for paper towels that are film-wrapped for ease of portability and hygiene. Therefore, by film-wrapping paper towels manufactured using TAD (Tissue-Assisted Dispensing), it is possible to create a product that combines the advantages of both TAD and film packaging.

[0005] As a prior art document for such paper towel packaging, for example, Patent Document 1 describes a paper towel packaging in which paper towel sheets of a composite nonwoven fabric containing synthetic fibers and pulp fibers are laminated in a pop-up manner and wrapped in film, with a film basis weight of 18 g / m². 2 More than 52g / m 2 The following conditions apply: the thickness is between 20 μm and 55 μm; the packaging has a perforation on the top surface to form a dispensing opening slit when opened; the value expressed as (length of the slit formed on the top surface of the packaging / length of the long side of the packaging) × 100 is between 50 and 100; and the basis weight of the paper towel sheet is 40 g / m². 2 More than 150g / m 2The following paper towel package is disclosed.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the case of a pop-up type paper towel, during use, when the number of sets decreases, a dropout (a phenomenon where the sheet comes off the outlet and falls inside the package, making it difficult to take out) occurs, resulting in poor usability.

[0008] To prevent dropout, it is conceivable to shorten the length of the film slit. However, there are problems such as film tearing or the sheet being easily torn when pulled out if the slit length is shortened.

[0009] On the other hand, by making the sheet length longer than a certain length, the "length coming out of the outlet" of the next sheet that comes out when pulled out becomes longer, so the occurrence rate of dropout can be suppressed. However, since the weight of the sheet increases as the sheet area increases, it may not be possible to pull out the next sheet together when pulling out.

[0010] Therefore, even if the sheet length is made longer than a certain length to prevent dropout, dropout is likely to occur as long as the basis weight of the sheet is not reduced to reduce the mass of the sheet itself (note that if the basis weight of the sheet is lowered, the water absorption and strength of the sheet will decrease, resulting in a problem of inferior quality as a paper towel).

[0011] While considering the above challenges, the inventor discovered that by manufacturing paper towels using TAD papermaking technology, it is possible to create paper-process-derived irregularities on the sheets. The roughness of these irregularities can be changed depending on the type of fabric used in the papermaking process.

[0012] By giving the sheet an appropriate degree of roughness and unevenness, even if the weight of the sheet increases, the unevenness makes it easier for the sheets to catch on each other, making it easier to pull them out together. This also allows the sheet length to be increased above a certain level without changing the sheet's basis weight, resulting in a design that is less prone to dropback while maintaining the sheet's water absorption and strength. Furthermore, we discovered that it can produce higher-quality paper towels because it improves absorbency and texture compared to regular paper towels.

[0013] This invention has been made in view of these circumstances, and aims to provide a paper towel packaging that suppresses drop-back during dispensing without reducing the basis weight of the paper towel sheets, while also providing good texture and water absorption of the paper towel sheets. [Means for solving the problem]

[0014] The inventors conducted diligent research and discovered that by stacking 2-ply or 3-ply paper towel sheets having an uneven pattern derived from the papermaking process, different from the embossed pattern, in a pop-up style and wrapping them in film, it is possible to create a paper towel package that suppresses dropback without reducing the basis weight, while also providing good texture and water absorption. This discovery solved the above problem and led to the completion of the present invention. In other words, the present invention provides the following:

[0015] (1) The first aspect of the present invention is a paper towel package obtained by laminating in a pop-up manner two-ply or three-ply paper towel sheets having uneven patterns derived from a papermaking process different from an embossed pattern, and then film-packaging, wherein the basis weight per ply of the paper towel sheet is 14 g / m 2 or more and 30 g / m 2 or less, the sheet length is 130 mm or more and 370 mm or less, the root mean square height of the surface roughness at the location where the embossed pattern is not applied is 25 μm or more and 130 μm or less, and the thickness of the film is 20 μm or more and 90 μm or less. It is a paper towel package characterized by the above.

[0016] (2) The second aspect of the present invention is the paper towel package according to (1), wherein the basis weight of the film is 20 g / m 2 or more and 80 g / m 2 or less.

[0017] (3) The third aspect of the present invention is the paper towel package according to (1) or (2), wherein the paper thickness at the product ply of the paper towel sheet is 0.30 mm or more and 1.30 mm or less.

[0018] (4) The fourth aspect of the present invention is the paper towel package according to (1) or (2), wherein the specific volume of the paper towel sheet is 7 cm 3 / g or more and 23 cm 3 / g or less.

[0019] (5) The fifth aspect of the present invention is the paper towel package according to (1) or (2), wherein the square root GMT of the product of the tensile strength DMDT in the MD direction and the tensile strength DCDT in the CD direction when the two-ply or three-ply paper towel sheet is dry is 1730 cN / 76 mm or more and 7900 cN / 76 mm or less.

[0020] (6) A sixth aspect of the present invention is a paper towel packaging according to (1) or (2), wherein the smoothness (TS750) measured by a tissue softness measuring device TSA in the portion of the paper towel sheet where the embossed pattern is not applied is 20 dBV 2 RMS or higher, 130 dBV 2 It is characterized by being less than or equal to rms.

[0021] (7) A seventh aspect of the present invention is a paper towel packaging according to (1) or (2), wherein [(sheet length of the paper towel sheet / 2) / √{(height dimension of the packaging) 2 + (Short side dimension of the packaging / 2) 2 The value calculated by} is characterized by being between 0.64 and 1.50.

[0022] (8) An eighth aspect of the present invention is a paper towel packaging according to (1) or (2), characterized in that the value calculated by ((basis weight of the film × thickness of the film) / (mass of the paper towel sheet / 2)) is 380 or more and 7000 or less. [Effects of the Invention]

[0023] According to the present invention, it is possible to provide a paper towel packaging that suppresses dropback during dispensing without reducing the basis weight of the paper towel sheets, and also provides good water absorption for the paper towel sheets. [Brief explanation of the drawing]

[0024] [Figure 1] This is a perspective view of the paper towel packaging according to this embodiment. [Figure 2] This figure shows an example of the shape of the slit for removing the sheets in the paper towel packaging of the present invention. [Figure 3] This is a cross-sectional view showing the state of a sheet immediately after it has been pulled out from the previous sheet in the paper towel packaging of the present invention. [Figure 4]This figure shows an example of an embossed pattern applied to a sheet in the paper towel packaging of the present invention. [Figure 5] This figure shows the height profile of the non-embossed area on the XY plane, as measured by a microscope, using shades of gray. [Figure 6] This figure shows a method for measuring the water absorption capacity of a sheet in the paper towel packaging of the present invention. [Figure 7] This figure shows a part of the papermaking process for the paper towel packaging of the present invention. [Modes for carrying out the invention]

[0025] The following describes in detail embodiments for carrying out the present invention (hereinafter simply referred to as "this embodiment"). This embodiment is illustrative for explaining the present invention and is not intended to limit the present invention to the following content. The present invention can be implemented by modifying it as appropriate within the scope of its gist.

[0026] In the context of paper towel sheets, the MD direction refers to the flow direction (Machine Direction) when the paper towel sheet is manufactured, while the CD direction refers to the direction perpendicular to the MD direction (Cross Direction). Furthermore, the long side direction of the paper towel packaging is the direction indicated by X in the diagram, the short side direction is the direction indicated by Y in the diagram, which is approximately perpendicular to the long side direction, and the height direction is the direction in which the paper towel sheets are stacked, which is indicated by Z in the diagram. In this case, if the dimensions of the long side direction and the dimensions of the short side direction of the paper towel packaging are equal (i.e., the top surface of the paper towel packaging is approximately square), or if the side perpendicular to the direction in which the slit extends is the long side, then the direction parallel to the slit (dispensing opening) direction is defined as the long side direction, regardless of the dimensions of each side. Furthermore, "product ply" refers to the number of plies in the paper towel sheet. For example, if a paper towel package is manufactured by laminating two sheets of paper towel material and then wrapping them in film, the product ply will be 2 plies. In addition, the paper towels (rolls, sheets) in this invention include kitchen towels and various types of paper towels (for wiper use).

[0027] <Paper towel packaging> Figure 1 is a perspective view of the paper towel packaging 1 (hereinafter also simply referred to as packaging 1) according to this embodiment. The paper towel packaging 1 according to this embodiment is made by stacking 2-ply or 3-ply paper towel sheets 10 having a different uneven pattern 23 (see Figure 4) derived from the papermaking process than the embossed pattern 20 (see Figure 4), in a pop-up manner, and packaging them with a film 2. In the laminate (hereinafter also referred to as a clip) formed by stacking the paper towel sheets 10 to be packaged in the film 2, it is preferable that the paper towel sheets 10 are folded parallel to the sheet width direction and stacked together with the front and rear paper towel sheets 10. The folding method is not particularly limited, but a V-fold is preferred. In this case, the inner surface of the V-folded paper towel sheet 10 is defined as the back side, and the outer surface is defined as the front side. Furthermore, it is preferable that the laminated sheets be processed by an interfolder (IF) type processing machine (processing by IF ensures that the drawing direction is the MD direction of the sheet).

[0028] As shown in Figure 1, it is preferable that the paper towel packaging 1 has a slit 3 on the top surface for removing (pulling out) the paper towel sheet 10. The slit 3 may or may not have perforations (i.e., the slit 3 is formed by cutting along the perforations), but it is preferable that it has perforations. In this case, the length SL of the slit 3 formed on the top surface of the packaging 1 is preferably 120 mm or more at the lower limit, more preferably 140 mm or more, and even more preferably 160 mm or more. The upper limit is preferably 300 mm or less, more preferably 275 mm or less, and even more preferably 255 mm or less. If the length SL is less than 120 mm, the load on the slit will increase when the paper towel sheet 10 is pulled out, making it more likely for the slit to tear and for the paper towel to drop back. If the length SL exceeds 300 mm, the paper towel sheet 10 will not easily catch on the slit 3, making it more likely for the paper towel to drop back.

[0029] Furthermore, the ratio (length SL of the slit 3 provided on the top surface of the packaging body 1 / dimension in the long side direction of the clip on which the paper towel sheets 10 are stacked) × 100 (%) is preferably 50% or more at the lower limit, more preferably 60% or more, and even more preferably 70% or more. The upper limit is preferably 145% or less, more preferably 135% or less, and even more preferably 125% or less. If the ratio is less than 50%, the length SL of the slit 3 is short relative to the dimension in the long side direction of the clip, making the slit more likely to tear when the paper towel sheet 10 is pulled out, and also making it more likely to drop back. If the ratio exceeds 145%, the length SL of the slit 3 is long relative to the dimension in the long side direction of the clip, making it less likely for the paper towel sheet 10 to catch on the slit 3, and making it more likely to drop back.

[0030] The slit 3 may be formed only on the top surface of the packaging body 1, or it may be formed continuously on the side surface of the packaging body 1. In this case, the length SL of the slit 3 formed on the top surface of the packaging body 1 is measured from the slit portion formed on the top surface of the packaging body 1 to the slit portion that continues to the side surface. Furthermore, while the slit 3 is preferably approximately straight as shown in Figure 2(a), it may also be shaped such that the starting and ending points coincide to form an opening (in this case, the opening is formed by cutting the perforations). In this case, the length SL of the slit 3 is measured from one end to the other of the opening, as in Figure 2(a).

[0031] In the packaging 1 according to this embodiment, the lower limit of the height Z dimension of the packaging 1 (i.e., the dimension of the height side 13 of the packaging) PH is preferably 30 mm or more, more preferably 40 mm or more, and even more preferably 50 mm or more. The upper limit is preferably 150 mm or less, more preferably 140 mm or less, and even more preferably 130 mm or less. If the height Z dimension PH is less than 30 mm, the number of paper towel sheets 10 that can be packaged will decrease, resulting in poor water absorption per pack of packaging 1. If the height Z dimension PH exceeds 150 mm, and the height Z dimension of the clips described later does not change, the difference between the height Z dimension PH of the packaging 1 and the height Z dimension of the remaining clips will increase as the number of clips decreases, making dropback more likely.

[0032] Furthermore, the dimension PW in the short-side direction Y of the packaging 1 (i.e., the dimension of the short side 12 of the packaging) is preferably 70 mm or more at the lower limit, more preferably 75 mm or more, and even more preferably 78 mm or more. The upper limit is preferably 190 mm or less, more preferably 165 mm or less, and even more preferably 145 mm or less. If the dimension PW in the short-side direction Y is less than 70 mm, the sheet length of the paper towel sheet 10, as described later, will be shorter, and as the number of sets decreases, the "length coming out of the slit 3" of the sheet being pulled out will be shorter, making it easier for the sheets to drop back. If the dimension PW in the short-side direction Y exceeds 190 mm, and the dimension of the clip in the short-side direction Y, as described later, does not change, the clip may move inside the packaging 1, and the "length coming out of the slit 3" of the sheet being pulled out may be shorter, making it easier for the sheets to drop back.

[0033] Furthermore, the dimension PL in the long side direction X of the packaging body 1 (i.e., the dimension of the long side 11 of the packaging body) is preferably 100 mm or more at the lower limit, more preferably 130 mm or more, and even more preferably 150 mm or more. The upper limit is preferably 290 mm or less, more preferably 270 mm or less, and even more preferably 250 mm or less. If the dimension PL in the long side direction X is less than 100 mm, the area of ​​the paper towel sheets 10 that can be packaged becomes small, resulting in poor water absorption per sheet. If the dimension PL in the long side direction X exceeds 290 mm, and the dimension in the direction of the clip (described later) does not change, the clip may move inside the packaging body 1, and the "length coming out of the slit 3" of the sheet that is pulled out may become shorter, making it more prone to dropback. The dimensions of packaging 1 are measured as follows (packaging 1 is used in its unopened state).

[0034] The method for measuring the height dimension PH of the packaging 1 in the Z direction is as follows: First, a 30 cm ruler (Shinwa Measuring Instruments Co., Ltd., straight ruler, silver, JIS Class 1, stainless steel, 64 g) is placed at the center of the short side 12 of the packaging 1 along the long side direction X (i.e., the direction approximately parallel to the long side 11 of the packaging 1), and the heights of both ends of the packaging 1 are measured. Similarly, a 30 cm ruler is placed at the center of the long side 11 of the packaging 1 along the short side direction Y (i.e., the direction approximately parallel to the short side 12 of the packaging 1), and the heights of both ends of the packaging 1 are measured. These four values ​​are averaged to obtain the final height dimension Z of the packaging 1 (dimension of the height side 13 of the packaging) PH. Furthermore, the method for measuring the dimension PL in the long side direction X of the packaging 1 is as follows: First, rotate the packaging 1 so that the short side (the surface consisting of the short side 12 and the height side 13) becomes the bottom surface. Then, place a 30cm ruler (Shinwa Measuring Instruments Co., Ltd. straight ruler silver JIS Class 1, stainless steel, 64g) at the center of the long side (short side 12) of the rectangle formed on the opposite short side which has become the top surface after rotation, and measure the heights of both ends (length from the bottom surface). Average these two values ​​to obtain the final dimension PL in the long side direction X of the packaging 1 (dimension of the long side 11 of the packaging). In addition, the method for measuring the dimension PW in the short side direction Y of the packaging 1 is as follows: Rotate the packaging 1 so that the long side (the surface consisting of the long side 11 and the height side 13) becomes the bottom surface, and similarly measure the heights of both ends (length from the bottom surface). Average these two values ​​to obtain the final dimension PW in the short side direction Y of the packaging 1 (dimension of the short side 12 of the packaging). If it is difficult for the packaging 1 to stand upright when rotated, a support can be used that does not affect the product dimensions.

[0035] In the packaging 1, the dimension of the clip in the long side direction X (i.e., the sheet width of the paper towel sheet 10) is preferably 100 mm or more at the lower limit, more preferably 130 mm or more, and even more preferably 150 mm or more. The upper limit is preferably 290 mm or less, more preferably 270 mm or less, and even more preferably 250 mm or less. If the dimension of the long side direction X is less than 100 mm, and the sheet length described later does not change, the area of ​​the paper towel sheet 10 will be smaller, resulting in inferior water absorption per sheet. If the dimension of the long side direction X exceeds 290 mm, and the length SL of the slit 3, the basis weight of the film 2, and the thickness of the film 2 do not change, the length SL of the slit 3 is shorter than the length PL of the clip, making the slit 3 more likely to tear when the paper towel sheet 10 is pulled out, and also more likely to drop back. In this case, the dimensions of the paper towel sheet 10 are defined as follows: the length parallel to the direction in which the paper towel sheet 10 is dispensed is defined as the "sheet length," and the length perpendicular to the direction in which the paper towel sheet 10 is dispensed is defined as the "sheet width."

[0036] Furthermore, the lower limit of the Y dimension of the clip is preferably 65 mm or more, more preferably 70 mm or more, and even more preferably 75 mm or more. The upper limit is preferably 190 mm or less, more preferably 160 mm or less, and even more preferably 140 mm or less. If the Y dimension in the short side direction is less than 65 mm, the area of ​​the paper towel sheet 10 becomes smaller, and the sheet length of the paper towel sheet 10 becomes shorter. As the number of sets decreases, the "length coming out of the slit 3" of the sheet being pulled out becomes shorter, making it more prone to dropback. If the Y dimension in the short side direction exceeds 190 mm, and the basis weight of the paper towel sheet 10 does not change, the sheet mass, as described later, becomes larger, and the film 2 on the top surface near the slit 3 cannot withstand the weight of the paper towel sheet 10, making it more prone to dropback.

[0037] Furthermore, the lower limit of the clip's height Z dimension is preferably 30 mm or more, more preferably 40 mm or more, and even more preferably 50 mm or more. The upper limit is preferably 150 mm or less, more preferably 140 mm or less, and even more preferably 130 mm or less. If the height Z dimension is less than 30 mm, the number of paper towel sheets 10 that can be packaged decreases, resulting in inferior water absorption per pack of the package 1. If the height Z dimension exceeds 150 mm, while the number of plies and sheets of paper towel sheets 10 remain unchanged, the paper thickness and basis weight increase instead. When the basis weight increases, the strength of the paper towel sheets 10 also increases, resulting in inferior texture. In addition, the sheet mass, described later, becomes larger relative to the shape retention of the film 2, and the film 2 at the top surface near the slit 3 cannot withstand the weight of the paper towel sheets 10, making dropback more likely.

[0038] To measure the dimensions of the clip in each direction, the dimension of the longer side (X) is measured by placing a 30cm ruler (Shinwa Measuring Instruments Co., Ltd., Silver Straight Ruler, JIS Class 1, Stainless Steel, 64g) along the longer side (X) of the clip at the center of the shorter side (Y) of the clip, and measuring the length (dimension) of the top surface. (To measure the dimension of the shorter side (Y), place the ruler along the shorter side (Y) of the clip at the center of the longer side (X). The height dimension Z is determined by placing a 30cm ruler (Shinwa Measuring Instruments Co., Ltd., straight ruler, silver, JIS Class 1, stainless steel, 64g) at the center of the clip's short side Y, along the clip's long side X, and measuring the height of both ends of the clip. Similarly, place a 30cm ruler at the center of the clip's long side X, along the clip's short side Y, and measure the height of both ends of the clip. These four values ​​are averaged to obtain the final height dimension Z of the clip.

[0039] Furthermore, the clip mass (clip mass) preferably has a lower limit of 90g or more, more preferably 120g or more, and even more preferably 140g or more. The upper limit is preferably 280g or less, more preferably 240g or less, and even more preferably 200g or less. If the mass is less than 90g, the basis weight will be lower if the dimensions, number of plies, and number of sheets of the paper towel sheet 10 remain unchanged. When the basis weight is low, the sheet becomes too soft and is difficult to hold in the slit 3, making dropback more likely, and when the product has 2 plies, the water absorption is also inferior. Also, if the sheet length is small, when the number of sheets decreases, the "length coming out of the slit 3" of the sheet that is pulled out becomes shorter, making dropback more likely. If the mass exceeds 280g, the basis weight will be higher if the dimensions and number of sheets of the paper towel sheet 10 remain unchanged. As the basis weight increases, the strength of the paper towel sheet 10 also increases, resulting in a less desirable texture. Furthermore, the sheet mass, as described later, becomes larger relative to the shape retention of the film 2. As a result, the film 2 at the top surface near the slit 3 cannot withstand the weight of the paper towel sheet 10, making dropback more likely.

[0040] Furthermore, the minimum number of paper towel sheets 10 included in the clip is preferably 20 or more, more preferably 30 or more, and even more preferably 40 or more. The maximum number of sheets is preferably 140 or less, more preferably 130 or less, and even more preferably 120 or less. If the number of sheets is less than 20, the water absorption per pack of the packaging 1 will be inferior. If the number of sheets exceeds 140, as the number of remaining sheets decreases, the difference between the height Z dimension PH of the packaging 1 and the height Z dimension of the remaining clips will increase, making dropback more likely.

[0041] (film) The film 2 for packaging the paper towel sheets 10 may be formed as a single layer or as a multi-layered film. The material of the film can be any plastic (thermoplastic resin) film used for packaging ordinary paper products, without any particular limitations, and it may also be surface-treated. Examples of conventionally known thermoplastic resins for the plastic film include polyolefins (polyethylene, polypropylene, etc.), polyesters (PET, etc.), polyamides (nylon, etc.), polycarbonate, polystyrene, and polyvinyl chloride, with polyolefins (polyethylene, polypropylene, etc.) being preferred. The polyethylene may be high-density polyethylene (HDPE), low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or a mixture of LDPE and LLDPE, but LDPE, LLDPE, and a mixture of LDPE and LLDPE are preferred.

[0042] In terms of specific configuration, when film 2 is formed as a single layer, it is preferable that the material of film 2 is one of the following selected from frosted polyethylene, milky polyethylene, linear low-density polyethylene, and unoriented polypropylene. When film 2 is formed as a multi-layer structure, it is preferable that the material of the outermost layer and / or innermost layer of film 2 is one of the following selected from frosted polyethylene, milky polyethylene, linear low-density polyethylene, and unoriented polypropylene. The method for textured film 2 is not particularly limited, and conventionally known methods can be employed, such as pressing the surface of film 2 against an embossing roll or mat roll during molding to create unevenness, or using a sandblasting method to create unevenness. Alternatively, methods that do not involve surface treatment, such as using a polymer blend or biaxially stretching a laminate of polyolefin resin blend, can also be employed.

[0043] Furthermore, the ash content of film 2 is preferably 1.5% to 12%, more preferably 2.0% to 10%, and even more preferably 2.5% to 8.0%. By keeping the ash content of film 2 within the above range, a package can be obtained that maintains appropriate shape retention and is less prone to drop-back. Note that the ash content of film 2 includes ash content derived from the ink. Ash content refers to the proportion of minerals such as calcium, iron, sodium, magnesium, phosphorus, and potassium, and is measured in accordance with JIS P 8251. Although ash content is supposed to be calculated using the following formula, the oven-dry mass of the test specimen is not measured; instead, the mass of the packaging substrate (film 2) test specimen after conditioning at 23°C and 50% humidity is considered the oven-dry mass.

[0044] Furthermore, the film 2 of the present invention may include other layers in addition to the film layer. Examples of other layers include a water vapor barrier layer, an oxygen barrier layer, a printing layer, a printability improving layer, an overprint layer, a light-shielding layer, and so on. These other layers can be provided, for example, on the surface that comes into contact with the paper product 11 or on the surface that comes into contact with the outside air, and may consist of one layer or two or more layers.

[0045] The basis weight of film 2 is 20 g / m². 2 More than 80g / m 2 Preferably, the basis weight of film 2 is 20 g / m². 2 If the basis weight is less than 80 g / m², the shape retention of film 2 is weak, and the top surface of film 2 near the slit 3 cannot withstand the weight of the sheet, making dropback more likely. 2 Beyond a certain point, the shape retention of film 2 becomes strong, and as the number of sets decreases, the difference between the height Z dimension of packaging 1 and the height Z dimension of the remaining clips becomes large, making them more prone to dropping back. Note that the lower limit of the basis weight of film 2 is 30 g / m². 2 It is more preferable that the amount be greater than or equal to 40 g / m 2 It is even more preferable that the value be greater than or equal to the above. Furthermore, the upper limit is 70 g / m². 2 More preferably, the following is true: 60 g / m 2The following is even more preferable: The basis weight of film 2 is measured in accordance with JIS P 8124.

[0046] Furthermore, the thickness of film 2 is between 20 μm and 90 μm. If the thickness of film 2 is less than 20 μm, the shape retention of film 2 is weak, and the top surface of film 2 near the slit 3 cannot withstand the weight of the sheet, making dropback more likely. If the thickness of film 2 exceeds 90 μm, the shape retention of film 2 is strong, and as the number of sets decreases, the difference between the height Z dimension of packaging 1 and the height Z dimension of the remaining clips becomes large, making dropback more likely. The thickness of film 2 is preferably 32 μm or more at the lower limit, and more preferably 42 μm or more. The upper limit is preferably 75 μm or less, and more preferably 65 μm or less. The thickness of film 2 is measured in accordance with JIS K 7130.

[0047] <Paper towel sheets> The paper towel sheet 10 according to this embodiment preferably contains wet pulp. Furthermore, the wet pulp content is preferably 50% by mass or more. If the wet pulp content is less than 50% by mass, the paper towel sheet 10 will have poor water absorption. While there is no specific upper limit set for the wet pulp content, if it is too high, the strength of the paper towel sheet 10 tends to increase, which may result in a less desirable texture. The wet pulp content in the paper towel sheet 10 is more preferably 70% by mass or more, and even more preferably 90% by mass or more. In this case, wet pulp refers to pulp in which the moisture content is 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 (approximately 10% by mass). Slush pulp (moisture content of approximately 95-97% by mass) is also included in wet pulp.

[0048] Furthermore, the pulp includes bleached softwood kraft pulp (NBKP) and bleached hardwood kraft pulp (LBKP). The preferred mass ratio of bleached softwood kraft pulp (NBKP) to bleached hardwood kraft pulp (LBKP) in the paper towel sheet 10 is 30-90% by mass: 10-70% by mass. If the mass ratio of NBKP is too low, the paper towel sheet 10 becomes too soft and difficult to hold in the slit 3, making dropback more likely. If the mass ratio of LBKP is too high, the paper towel sheet 10 becomes too soft and difficult to hold in the slit 3, making dropback more likely. In the paper towel sheet 10, the mass ratio of bleached softwood kraft pulp (NBKP) to bleached hardwood kraft pulp (LBKP) is more preferably NBKP:LBKP = 40-80% by mass:20-60% by mass, and even more preferably NBKP:LBKP = 50-70% by mass:30-50% by mass.

[0049] Furthermore, for pulp processing, NBKP is preferably beaten, while LBKP is preferably not beaten. In addition, other pulps (such as recycled pulp) may be included in a ratio of preferably 20% by mass, more preferably 10% by mass, even more preferably 5% by mass, and most preferably 0% by mass, relative to the ratio of NBKP to LBKP.

[0050] (Basic weight) The basis weight per ply of paper towel sheet 10 is 14 g / m². 2 More than 30g / m 2 The following applies: The basis weight per ply is 14 g / m². 2 If the basis weight is less than 30g / m², the paper towel sheet 10 becomes too soft and is not easily held in the slit 3, making dropbacks more likely, and the absorbency is inferior when the product has 2 plies. 2 If this limit is exceeded, the strength of the paper towel sheet 10 becomes too high, resulting in a poor texture. Furthermore, the sheet mass becomes too large relative to the shape retention capacity of the film 2, and the film 2 at the top surface near the slit 3 cannot withstand the weight of the sheet, making dropback more likely. The basis weight per ply of the paper towel sheet 10 has a minimum value of 16 g / m². 2 Preferably, it is 18 g / m² or more. 2 It is more preferable that the value is greater than or equal to the above. Furthermore, the upper limit is 29 g / m². 2 Preferably, it is 28 g / m 2 The following is more preferable: The basis weight per ply of the paper towel sheet 10 can be measured according to JIS P 8124.

[0051] (paper thickness) Furthermore, the paper thickness of the product ply of the paper towel sheet 10 is preferably 0.30 mm or more and 1.30 mm or less. If the paper thickness is less than 0.30 mm, the paper towel sheet 10 will have poor water absorption and poor texture. If the paper thickness exceeds 1.30 mm, the basis weight will increase, provided that the specific volume (described later) does not change. When the basis weight increases, the strength of the paper towel sheet 10 also increases, resulting in poor texture. In addition, the sheet mass (described later) becomes larger relative to the shape retention of the film 2, and the film 2 at the top surface near the slit 3 cannot withstand the weight of the paper towel sheet 10, making dropback more likely. Furthermore, if the root mean square height Sq of the surface roughness (described later) becomes large, the paper towel sheet 10 will have poor texture. Furthermore, the paper thickness of the product ply of the paper towel sheet 10 is more preferably 0.38 mm or more at the lower limit, and even more preferably 0.46 mm or more. The upper limit is more preferably 1.23 mm or less, and even more preferably 1.17 mm or less.

[0052] The paper thickness of the paper towel sheet 10 can be measured using a thickness gauge (a dial thickness gauge "PEACOCK" manufactured by Ozaki Seisakusho Co., Ltd.). The measurement conditions are a measuring load of 3.7 kPa and a probe diameter of 30 mm. The sample is placed between the probe and the measuring stand, and the gauge is read when the probe is lowered at a speed of 1 mm or less per second. As a sample, the paper towel sheet 10 will be measured in its original ply count (2 plies for 2-ply products, 3 plies for 3-ply products). The measurement will be repeated 10 times at different locations, and the average of the measurement results will be used as the final paper thickness of the paper towel sheet 10.

[0053] (Sheet length) The sheet length (length of the paper towel sheet 10 in the pulling direction) SHL of the paper towel sheet 10 is between 130 mm and 370 mm. If the sheet length SHL is less than 130 mm, as the number of paper towel sheets 10 decreases, the length of the sheet that comes out of the slit 3 becomes shorter, making it more likely to drop back. If the sheet length SHL exceeds 370 mm, if the basis weight of the paper towel sheet 10 does not change, the mass of the sheet (described later) increases instead, so the film 2 at the top surface near the slit 3 cannot withstand the weight of the paper towel sheet 10, making it more likely to drop back. Furthermore, the sheet length SHL of the paper towel sheet 1x is preferably 140 mm or more at the lower limit, and more preferably 150 mm or more. The upper limit is preferably 320 mm or less, and more preferably 280 mm or less.

[0054] (Sheet weight) The sheet mass per product ply of the paper towel sheet 10 (hereinafter also simply referred to as "sheet mass") is preferably 1.2g or more at the lower limit, more preferably 1.5g or more, and even more preferably 1.7g or more. The upper limit is preferably 5.0g or less, more preferably 4.2g or less, and even more preferably 4.0g or less. If the sheet mass is less than 1.2g, the basis weight will decrease if the dimensions and number of plies of the paper towel sheet 10 remain unchanged. When the basis weight decreases, the sheet becomes too soft and is not easily held in the slit 3, making dropback more likely, and when the product ply is 2 plies, the water absorption is also inferior. In addition, if the sheet length is reduced, the "length coming out of the slit 3" of the sheet that is pulled out becomes shorter as the number of sets decreases, making dropback more likely. If the sheet mass exceeds 5.0g, the film 2 on the top surface near the slit 3 will not be able to withstand the weight of the paper towel sheet 10, making dropback more likely. The sheet mass per ply of the paper towel sheet 10 is measured by the following formula: basis weight per ply of paper towel sheet 10 × (sheet length (mm) / 1000) × (sheet width 210 (mm) / 1000) × number of plies of paper towel sheet 10. As shown in the formula, the mass of the paper towel sheet 10 is calculated as the mass per sheet width of 210 mm.

[0055] Note that [(Sheet length of paper towel sheet 10 SHL / 2) / √{(Dimension Z of packaging 1 PH) 2 +(Dimension of the short side Y of packaging 1: PW / 2) 2It is preferable that the value calculated by}] is between 0.64 and 1.50. This value represents the ratio of "half the sheet length SHL of the paper towel sheet 10" to "the straight-line distance from the long side of the bottom of the packaging 1 to the slit". In other words, the larger the value, the longer the "length coming out of the slit" of the paper towel sheet 10 when the number of sheets decreases, and the smaller the value, the shorter the "length coming out of the slit". If the value is less than 0.64, when the number of sheets of paper towel sheet 10 inside the packaging 1 decreases, the "length coming out of the slit 3" of the sheet being pulled out becomes shorter, making it more likely to drop back. If the value exceeds 1.50, if the sheet length SHL of the paper towel sheet 10 is long, the sheet mass per product ply will increase as a result, and the film 2 on the top surface near the slit 3 will not be able to withstand the weight of the paper towel sheet 10, making it more likely to drop back. [(Sheet length of paper towel sheet 10 SHL / 2) / √{(Dimension Z of packaging 1 PH) 2 +(Dimension of the short side Y of packaging 1: PW / 2) 2 The value calculated by [ ] is more preferably 0.70 or higher at the lower limit, and even more preferably 0.85 or higher. Furthermore, the upper limit is more preferably 1.30 or lower, and even more preferably 1.20 or lower.

[0056] Furthermore, it is preferable that the value calculated by ((basis weight of film 2 × thickness of film 2) / (sheet mass of paper towel sheet 10 / 2)) be between 380 and 7000. If the value is less than 380, the shape retention of film 2 is weak, and the top surface of film 2 near the slit 3 cannot withstand the weight of the paper towel sheet 10, making dropback more likely. If the value exceeds 7000, the shape retention of film 2 is strong, and as the number of sets decreases, the difference between the height Z dimension of the packaging 1 and the height Z dimension of the remaining clips becomes large, making dropback more likely. Furthermore, the value calculated by ((basis weight of film 2 × thickness of film 2) / (sheet mass of paper towel sheet 10 / 2)) is more preferably 950 or higher at the lower limit, and even more preferably 1600 or higher. Also, the upper limit is more preferably 5200 or lower, and even more preferably 3800 or lower.

[0057] Each of the above values ​​is determined in accordance with the cross-sectional view shown in Figure 3, which illustrates the state in which the paper towel sheet 10 is being removed from the packaging 1. That is, when the paper towel sheet 10 of the packaging 1 is folded in a V-shape, and half of the sheet length SHL of the paper towel sheet 10 is taken as SHL / 2, then √{(the dimension PH in the height direction Z of the packaging 1) 2 +(Dimension of the short side Y of packaging 1: PW / 2) 2} is the diagonal length DL shown in Figure 3, and (SHL / 2 / DL) calculates a value that represents the ratio of "half the sheet length SHL in the paper towel sheet 10" to "the straight-line distance from the long side of the bottom side of the packaging 1 to the slit" (Note that although Figure 3 shows only one sheet, the actual laminated state of the paper towel sheet 10 is a state in which V-folded sheets are stacked alternately). Furthermore, ((basis weight of film 2 × thickness of film 2) / (sheet mass per product ply of paper towel sheet 10 / 2)) is calculated by determining the sheet mass per product ply (sheet mass per product ply of paper towel sheet 10 / 2) for half the sheet length SHL of paper towel sheet 10 and a sheet width of 210 mm, and then calculating the ratio of the shape retention of film 2 to that mass, which is obtained by multiplying the basis weight and thickness of film 2.

[0058] (specific volume) The specific volume of paper towel sheet 10 is 7 cm³. 3 / g or more 23cm 3 It is preferable that the specific volume of the paper towel sheet 10 is 7 cm³ or less. 3If the basis weight of the paper towel sheet 10 is less than 23 cm³, the paper thickness will decrease instead, resulting in inferior water absorption and texture. 3 If the amount exceeds / g, the basis weight will decrease if the paper thickness of the paper towel sheet 10 remains unchanged. When the basis weight decreases, the paper towel sheet 10 becomes too soft and is not easily held in the slit 3, making dropbacks more likely, and when the product has 2 plies, the water absorption is inferior. The specific volume of the paper towel sheet 10 has a lower limit of 9 cm³. 3 It is more preferable that it be 11cm or more / g. 3 It is even more preferable that the value be 20cm or more. The upper limit is 20cm. 3 It is more preferable that it be less than or equal to / g, and 17cm 3 It is even more preferable that it be less than or equal to / g. The specific volume is calculated by dividing the paper thickness per ply of the paper towel sheet 10 by the basis weight per ply (paper thickness per product ply = basis weight per product ply), and the volume per unit (g) (cm³). 3 It is represented as ).

[0059] (DMDT and DCDT) The Dry Machine Direction Tensile Strength (DMDT) of the paper towel sheet 10 in the MD direction per 2-ply or 3-ply during dry conditions is preferably 2000 cN / 76 mm or more at the lower limit, more preferably 2400 cN / 76 mm or more, and even more preferably 2800 cN / 76 mm or more. The upper limit is preferably 8000 cN / 76 mm or less, more preferably 7100 cN / 76 mm or less, and even more preferably 6800 cN / 76 mm or less. If the DMDT is less than 2000 cN / 76 mm, the paper towel sheet 10 becomes too soft and is difficult to hold in the slit 3, making dropback more likely. Also, if the DMDT exceeds 8000 cN / 76 mm, the paper towel sheet 10 will have an inferior texture.

[0060] Furthermore, the Dry Cross Direction Tensile Strength (DCDT) of the paper towel sheet 10 per 2-ply or 3-ply sheet during dry conditions is preferably 1700 cN / 76 mm or more at the lower limit, more preferably 1900 cN / 76 mm or more, and even more preferably 2200 cN / 76 mm or more. The upper limit is preferably 7800 cN / 76 mm or less, more preferably 6350 cN / 76 mm or less, and even more preferably 5900 cN / 76 mm or less. If the DCDT is less than 1700 cN / 76 mm, the paper towel sheet 10 becomes too soft and difficult to hold in the slit 3, making dropback more likely. Also, if the DCDT exceeds 7800 cN / 76 mm, the paper towel sheet 10 will have an inferior texture.

[0061] Furthermore, the Geometric Tensile Strength (GMT), which is the square root of the product of DMDT and DCDT per 2-ply or 3-ply, is preferably between 1730 cN / 76 mm and 7900 cN / 76 mm. If the GMT is less than 1730 cN / 76 mm, the paper towel sheet 10 becomes too soft and difficult to hold in the slit 3, making dropback more likely. If the GMT exceeds 7900 cN / 76 mm, the paper towel sheet 10 will have an inferior texture. Furthermore, the GMT, which is the square root of the product of DMDT and DCDT per 2-ply or 3-ply, is more preferably 2100 cN / 76 mm or more at the lower limit, and even more preferably 2400 cN / 76 mm or more. The upper limit is more preferably 6720 cN / 76 mm or less, and even more preferably 6400 cN / 76 mm or less. Also, when calculating GMT, if DMDT is per 2 plies, DCDT is also calculated as the value per 2 plies, and when calculating GMT, if DMDT is per 3 plies, DCDT is also calculated as the value per 3 plies.

[0062] The DMDT and DCDT per 2-ply or 3-ply paper towel sheet 10 shall be measured in accordance with JIS P 8113. GMT shall be calculated as the square root of the product of their tensile strengths. Similarly, if the paper towel sheet 10 is 3-ply, the measurements shall be taken for all 3 plies in accordance with JIS P 8113.

[0063] (Embossed) The paper towel sheet 10 included in the packaging 1 of this embodiment is preferably embossed and preferably has an embossed pattern 20. Furthermore, the paper towel sheet 10 in the present invention is preferably embossed on at least one ply and then laminated to form two or three plies. When laminating to form two or three plies, it is preferable to use, for example, plybond glue (adhesive) and apply the glue to perform the bonding treatment. By bonding in this way to form two or three plies, the adhesion between the plies is strengthened, and the paper towel sheet 10 becomes less likely to tear even when wet, as the plies will not peel off. Alternatively, water may be used instead of plybond glue (adhesive), or the glue and water may be mixed. Furthermore, if the paper towel sheet 10 has fewer than 2 plies, the paper towel sheet 10 will have poor water absorption. If the paper towel sheet 10 has more than 3 plies, and the basis weight of the paper towel sheet 10 remains the same, the sheet mass per product ply will increase instead, causing the film 2 at the top surface near the slit 3 to be unable to withstand the weight of the paper towel sheet 10, making dropback more likely.

[0064] It is preferable that the surface ply of the paper towel sheet 10 has an embossed pattern 20. By applying the embossed pattern 20 to the surface, glue can be applied to the embossed area and laminated into two plies. If the paper towel sheet 10 does not have an embossed pattern 20, the paper towel sheet 10 will have poor water absorption. Also, since the ply bond glue will be applied to the entire surface of the paper towel sheet 10, the strength of the paper towel sheet 10 will increase and the texture will be inferior.

[0065] Figure 4 shows an example of the embossing pattern 20 in the paper towel packaging 1 of this embodiment. The embossed pattern 20 preferably includes a continuous emboss 21 and a closed-ring structure emboss 22, and it is preferable that each of the continuous emboss 21 and the closed-ring structure emboss 22 is arranged in a fixed pattern. By including the continuous emboss 21 and the closed-ring structure emboss 22 in the embossed pattern 20, a paper towel sheet 10 with excellent texture and water absorption can be made.

[0066] The continuous embossing 21 is not particularly limited in its overall shape, but it is preferable that it has a repeating structure of straight lines and curves that extends across the entire paper towel sheet 10. Including the continuous embossing 21 in the embossing pattern 20 results in a good texture on the paper towel sheet 10. While it is preferable that the entire pattern of the continuous embossing 21 is continuous, the straight lines and curves that form the embossing do not have to be continuous within the pattern and may be interrupted. Furthermore, the continuous embossing 21 may also include patterns of dashed lines or dots less than 5 mm in length, but it is preferable that it is a pattern of linear embossing with a length of 5 mm or more. The closed-ring structure embossing 22, like the continuous embossing 21, is not particularly limited in its overall shape, but it is preferable that it includes a dot or graphic embossing in the center surrounded by a graphic embossing on the outside to form a closed-ring structure. The inclusion of the closed-ring structure embossing 22 in the embossing pattern 20 results in good water absorption in the paper towel sheet 10.

[0067] The embossed pattern 20 includes linear embossed portions 24, but it is preferable that the proportion of linear embossed portions 24 included in the embossed pattern 20 is 20% or more. If the proportion is less than 20%, the embossed pattern 20 cannot contribute to improving the texture and water absorption, and the paper towel sheet 10 will be inferior in texture and water absorption. Furthermore, the proportion of linear embossed portions 24 included in the embossed pattern 20 is more preferably 50% or more, and even more preferably 90% or more.

[0068] In this case, the linear embossed portion 24 refers to an embossed surface with a thickness of 0.1 mm or more and a length of 5 mm or more. Even if an embossed surface is included in the continuous embossing 21 or the closed-ring structure embossing 22, if it meets the above thickness and length requirements, it is included in the linear embossed portion 24. The proportion of the linear embossed portion 24 is determined as follows. First, divide any 100mm x 100mm area on the embossed surface of the paper towel sheet 10 into 10mm squares. Then, calculate the proportion of the linear embossed area 24 using the following formula. If a single square contains both linear and dot embossing, use the square with the larger proportion of embossing. (Number of squares with linear embossing / Number of squares with any type of embossing) × 100 = Percentage of linear embossing (24%)

[0069] Furthermore, there are no particular restrictions on whether the ply on the back side of the paper towel sheet 10 has an embossed pattern 23 derived from a papermaking process different from the embossed pattern 20 described later. Nested embossing or pin-to-pin embossing may be applied, or no embossing may be applied, but nested embossing or no embossing is preferred, and more preferably no embossing. Furthermore, if the paper towel sheet 10 is 3-ply, the ply between the front ply and the back ply may or may not have an embossed pattern, but it is preferable to have an embossed pattern on the two front plies and no embossing on the back.

[0070] Furthermore, the root mean square height Sq of the surface roughness in the portion of the paper towel sheet 10 that does not have the embossed pattern 20 (hereinafter also referred to as the non-embossed portion) is between 25 μm and 130 μm. If the root mean square height Sq of the surface roughness is less than 25 μm, the unevenness of the sheet becomes smaller, resulting in poor water absorption of the paper towel sheet 10, and making it difficult to pull out the paper towel sheet 10 together with the previous sheet when it is pulled out, making dropback more likely. If the root mean square height Sq of the surface roughness exceeds 130 μm, the unevenness of the sheet becomes larger, resulting in a poor texture for the paper towel sheet 10. Furthermore, the root mean square height Sq of the surface roughness in the non-embossed portion of the paper towel sheet 10 is preferably 35 μm or more, more preferably 40 μm or more, and preferably 115 μm or less, and more preferably 100 μm or less.

[0071] The root mean square height (Sq) of the surface roughness of the non-embossed area is measured using a microscope. The KEYENCE VR-6100 one-shot 3D shape measuring machine can be used as the microscope. The VR-6000 observation application software can be used for observing and measuring the microscope image, and the VR-6000 analysis application can be used for image analysis. The measurement conditions are 38x magnification and a field of view of 8mm x 6mm. If the proportion of the embossed area is large and it is not possible to measure only the non-embossed area under the above conditions, the magnification and field of view may be changed as appropriate.

[0072] Figure 5 shows the height profile of the non-embossed area on the XY plane as measured by a microscope, using shades of gray. The obtained image shown in Figure 5 is then filtered. Specifically, by setting an S-filter (low-pass filter), components on a scale smaller than the cutoff wavelength are removed from the image, and by setting an L-filter (high-pass filter), components on a scale larger than the cutoff wavelength are removed. Here, the S-filter is set to 500 μm and the L-filter to 8 mm. Once the S-filter and L-filter are selected, the root mean square height Sq is calculated automatically.

[0073] For the non-embossed portion, 10 paper towel sheets 10 are taken from the paper towel packaging 1, and the 11th and 12th paper towel sheets 10 are used to measure the height in their sheet state without changing the number of plies. Two measurements are taken in the MD direction of each paper towel sheet 10, and then two measurements are taken in the CD direction. The average of these eight measurements (2 measurements × 2 directions × 2 sheets) is finally adopted as the root mean square height Sq. The measurement will be taken on the back side of the paper towel sheet 10, and on the front side of the paper towel sheet 10 where the embossed pattern 20 is applied, the measurement will be taken on the area where the ply is not adhered with plybond glue.

[0074] (Water absorption) The minimum water absorption per unit area of ​​a 2-ply or 3-ply paper towel sheet 10 is 200 g / m². 2 Preferably, it should be 260 g / m² or more. 2 It is more preferable that the amount be greater than or equal to 300 g / m². 2 It is even more preferable that the value be greater than or equal to the above. Furthermore, the upper limit is 800 g / m². 2 Preferably, it is 730 g / m². 2 It is more preferable that the following conditions apply: 700 g / m² 2 It is even more preferable that the following conditions are met: Water absorption per unit area is 200 g / m². 2 If the water absorption is less than 800 g / m², the paper towel sheet 10 will have poor water absorption. 2If it exceeds this limit, and the number of plies remains the same, the basis weight of the paper towel sheet 10 will increase instead. When the basis weight increases, the strength of the paper towel sheet 10 also increases, resulting in a less desirable texture. Furthermore, the sheet mass, as described later, becomes larger relative to the shape retention of the film 2, and the film 2 at the top surface near the slit 3 cannot withstand the weight of the paper towel sheet 10, making dropback more likely.

[0075] Furthermore, for 2-ply or 3-ply paper towel sheets 10, the water absorption per unit mass is preferably 6 g / g or more at the lower limit, more preferably 7 g / g or more, and even more preferably 8 g / g or more. The upper limit is preferably 20 g / g or less, more preferably 18 g / g or less, and even more preferably 16 g / g or less. If the water absorption per unit mass is less than 6 g / g, the paper towel sheet 10 will have poor water absorption. If the water absorption per unit mass exceeds 20 g / g, the root mean square height Sq of the surface roughness will increase if the number of plies does not change, and the paper towel sheet 10 will have poor texture.

[0076] The method for measuring the water absorption capacity of each paper towel sheet 10 will be explained below, with reference to Figure 6. First, a two-ply stacked paper towel sheet 10 is taken and cut using a 7.6cm square template to create a rectangular test piece 30 with sides of 7.6cm. The mass of the test piece 30 before water absorption is measured using an electronic balance. The test piece 30 is then placed in a holder 31 (a jig that secures the test piece at three points; the jig is made of a metal that does not absorb moisture).

[0077] Next, fill a commercially available tray with distilled water to a depth of 2 cm, and immerse the test piece 30, which is set in the holder 31, in the distilled water for 2 minutes. After 2 minutes of immersion, remove the test piece 30 together with the holder 31 from the distilled water, and as shown in Figure 6, hang the holder 31 and the test piece 30 from a rod placed in an empty water tank with the corner 30a facing upwards, close the lid of the water tank, and leave it for 5 minutes.

[0078] Afterward, the holder 31 and the test piece 30 are removed from the water bath, the holder 31 is removed, and the mass of the test piece 30 is measured using an electronic balance. From the change in mass of the test piece 30 before and after immersion in distilled water, the amount of distilled water absorbed per unit area of ​​the test piece 30 (water g / sheet m) is determined. 2 , 1m 2 Correct. Abbreviated as g / m 2 Calculate the amount of water absorbed per unit area (water g / sheet m). 2 By dividing this by the basis weight of the product ply of test piece 30, the water absorption per unit area (water g / sheet m) can be calculated. 2 ) / Basis weight (sheet g / sheet m 2 Calculate the water absorption per unit mass (g of water / g of sheet, per gram; abbreviated as g / g). Measure each sample 5 times and use the average value.

[0079] Furthermore, even if the paper towel sheet 10 is 3-ply, it is preferable to measure it as is, using the same procedure as for the 2-ply sheet. This measurement will be performed according to the JIS P 8111 method, under conditions of 23±1°C and 50±2% humidity. Distilled water will also be maintained at 23±1°C.

[0080] (TS750) Furthermore, in the paper towel sheet 10, the smoothness (TS750) measured by the tissue softness measuring device TSA in areas where the embossed pattern 20 is not applied is 20 dBV. 2 RMS or higher, 130 dBV 2 It is preferable that the RMS value is 20 dBV or less. 2 If the rms is less than 130dBV, the surface roughness of the paper towel sheet 10 is small, resulting in poor water absorption. Furthermore, when pulling out a paper towel sheet 10, it becomes difficult to pull it out together with the previous sheet, making dropback more likely. (TS750 is 130dBV) 2 If the rms (Real-times) value exceeds a certain level, the unevenness of the sheet increases, resulting in a less desirable texture for the paper towel sheet 10. Furthermore, in the paper towel sheet 10, the smoothness (TS750) measured by the tissue softness measuring device TSA in areas without an embossed pattern has a lower limit of 35 dBV. 2 Preferably rms or higher, and 55 dBV 2 A value of rms or higher is preferable. The upper limit is 120 dBV. 2 Preferably, it should be rms or less, and 110 dBV 2 It is more preferable that the RMS value is less than or equal to the RMS value.

[0081] The smoothness (TS750) measured by the Tissue Softness Analyzer (TSA) in areas of the paper towel sheet 10 without an embossed pattern is the intensity of the first maximum peak in the spectrum from the low-frequency side, automatically acquired by the software on the TSA when the TSA (manufactured by emtec) is used to measure the smoothness of the paper towel sheet 10 sample placed on the sample stage, after which a bladed rotor is pressed down from above with a pressing pressure of 100 mN and then rotated at a rotation speed of 2.0 / sec, and the vibration of the sample stage is measured by a vibration sensor. Regarding the area to be measured, the area on the surface 1a side of the paper towel sheet 10 without an embossed pattern 20 is measured. If no such area exists, the area on the back side 1b side without an embossed pattern 20 is measured, and if no such area exists either, the area on the surface 1a side including the embossed pattern 20 is measured. In addition, when measuring with the TSA, the paper towel sheet 10 is measured in its product ply form. The method for measuring the TS750 value using the TSA tissue softness measuring device, and the measuring device used, are described in detail, for example, in Japanese Patent Publication No. 2013-236904. For various measurement methods using the TSA tissue softness measuring device, please refer to the above-mentioned patent document.

[0082] <Manufacturing method for paper towel packaging> There are no particular restrictions on the manufacturing method of the paper towel packaging 1 according to this embodiment, and it can be manufactured by known methods for manufacturing laminated thin paper products. Such a manufacturing method may include steps such as (1) papermaking and creping, (2) embossing and bonding, (3) cutting and folding, (4) lamination, (5) cutting of the laminate, and (6) film packaging, although some steps may be performed in any order. In addition, it is preferable to use the TAD papermaking method in the manufacturing (papermaking) process of the paper towel sheet 10. Furthermore, (6) in film packaging, the packaging form of the paper towel packaging 1 according to this embodiment is preferably gusset packaging, pillow packaging or caramel packaging, and more preferably caramel packaging.

[0083] At this time, in the papermaking process, as shown in Figure 4, a different uneven pattern 23 originating from the papermaking process (fabric) is applied to the paper towel sheet 10, which is different from the embossed pattern 20 described above. If this uneven pattern 23 is not present, it becomes difficult to pull out the next sheet together when pulling out the paper towel sheet 10, making dropback more likely.

[0084] Furthermore, "originating from the papermaking process" means that in the papermaking process of the paper towel sheet 10, a pattern of bumps and dips is applied between the headbox 41 of the papermaking machine and the outlet of the Yankee dryer 46. Specifically, in a part of the papermaking process shown in Figure 7, a paper web 40a in the state of pulp slurry is sprayed (supplied) from the headbox 41 between the first fabric (forming fabric) 42 and the second fabric (bumpy fabric) 43, and is drawn onto the second fabric (bumpy fabric) 43 by the forming roll 44, forming a paper web 40b in the state of wet paper.

[0085] Next, the paper web 40b is dried together with the second fabric (textured fabric) 43 in the through-air dryer 45, resulting in the formation of texture on the dried sheet of paper web 40c. In Figure 7, two through-air dryers 45 are shown, but one unit may suffice. Also, a Yankee hood is shown on the Yankee dryer 46, but the hood is not required. Furthermore, a crepe texture may be applied in the Yankee dryer 46.

[0086] Furthermore, the uneven surface pattern 23 can be changed as appropriate by changing the fabric pattern (fine pattern, coarse pattern). Changing the uneven surface pattern 23 changes the root mean square height Sq of the surface roughness, but it is preferable to select a pattern such that the root mean square height Sq of the surface roughness falls within the numerical range described above.

[0087] As described above, according to this embodiment, it is possible to provide a paper towel packaging that suppresses dropback during dispensing without reducing the basis weight of the paper towel sheet, and also provides good texture and water absorption of the paper towel sheet.

[0088] Although the present invention has been described above using embodiments, it goes without saying that the technical scope of the present invention is not limited to the scope described in the above embodiments. It will be obvious to those skilled in the art that various modifications or improvements can be made to the above embodiments. Furthermore, it is clear from the claims that such modified or improved forms may also be included in the technical scope of the present invention. [Examples]

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

[0090] Under the conditions shown in Tables 2 to 4, paper towel (kitchen towel) packaging for Examples 1 to 22 and Comparative Examples 1 to 9 was prepared and then evaluated as follows. For all Examples and Comparative Examples, the sheets were folded in a V-shape, creating a pop-up type. The lengths of the long and short sides of the packaging were measured using a ruler. For each of the evaluations below, a score of 1 was considered a failure, and a score of 2 or higher was considered a pass. In addition, all parameters other than those evaluated below were measured according to the criteria or measurement methods described above.

[0091] (Texture of the sheet) Regarding the texture of paper towel sheets in paper towel packaging, 30 monitors conducted a sensory evaluation of the texture when a paper towel sheet was pulled from the packaging and touched by hand. The evaluation was rated on a 5-point scale based on the number of people who felt that "the sheet was rough and had an inferior texture." The evaluation criteria were as follows: 5: 0-1 person felt that the seat was stiff and lacked texture. 4: 2-3 people felt that the seat was stiff and lacked texture. 3: 4-5 people felt that the seat was stiff and lacked texture. 2: 6-7 people felt that the seat was stiff and lacked texture. 1: Eight or more people felt that the seat was stiff and lacked texture.

[0092] (Water absorption of the sheet) The water absorption of paper towel sheets in paper towel packaging was evaluated based on the water absorption per unit area and per unit mass of 2-ply or 3-ply paper towel sheets. The evaluation was then categorized into four levels based on these values. The evaluation criteria are shown in Table 1 below. [Table 1]

[0093] (Difficulty of dropping back when removing) The resistance of paper towel sheets to dropping back in paper towel packaging was evaluated on a 5-point scale based on the total number of times paper towel sheets dropped back when all three packs of paper towels were pulled out. The evaluation criteria were calculated as follows: [Total number of times dropped back / Total number of sheets in 3 packs] × 100 (%). 5 points: The value calculated by the above formula is less than 3% 4 points: The value calculated by the above formula is 3% or more but less than 5%. 3. The value calculated by the above formula is between 5% and less than 8%. 2. The value calculated by the above formula is between 8% and less than 10%. 1 point: The value calculated by the above formula is 10% or more.

[0094] [Table 2]

[0095] [Table 3]

[0096] [Table 4]

[0097] As is clear from the results shown in Tables 2 to 4, the paper towel packaging of Examples 1 to 22 was good in terms of sheet texture, water absorption, and resistance to dropping back during dispensing. In contrast, the paper towel packaging of Comparative Examples 1 to 9 was inferior in either the sheet texture, water absorption, or resistance to dropping back during dispensing. Therefore, it has been confirmed that the paper towel packaging of the present invention can provide a paper towel packaging that suppresses dropback during dispensing without reducing the basis weight of the paper towel sheets, and also provides good texture and water absorption of the paper towel sheets. [Explanation of Symbols]

[0098] 1 (Paper towel) packaging 2 films 3 slits 10 paper towel sheets 11 Long side of the packaging 12 Packaging short side 13. Package height side 20 Embossing Patterns 21 consecutive embossing 22 Ring-closed structure embossing 23 uneven pattern 24 Linear embossed area 30 test specimens 30a Corner 31 Holder 40a, 40b, 40c Paper Web 41 Headbox 42,43 Fabric 44 Foaming Roll 45 Through Air Dryer 46 Yankee Hair Dryer

Claims

1. A paper towel package comprising two-ply or three-ply paper towel sheets having an uneven pattern derived from the papermaking process, different from an embossed pattern, laminated in a pop-up manner and film-wrapped, The basis weight per ply of the aforementioned paper towel sheet is 14 g / m². ２ 30g / m or more ２ The following conditions apply: the sheet length is 130 mm or more and 370 mm or less, and the root mean square height of the surface roughness in areas where the embossed pattern is not applied is 25 μm or more and 130 μm or less. A paper towel packaging characterized in that the thickness of the film is 20 μm or more and 90 μm or less.

2. The basis weight of the aforementioned film is 20 g / m². ２ 80g / m or more ２ The paper towel packaging according to claim 1, characterized in that it is as follows.

3. The paper towel packaging according to claim 1 or 2, characterized in that the paper thickness in the product ply of the paper towel sheet is 0.30 mm or more and 1.30 mm or less.

4. The specific volume of the aforementioned paper towel sheet is 7 cm³. ３ / g or more 23cm ３ The paper towel packaging according to claim 1 or 2, characterized in that it is less than or equal to / g.

5. The paper towel packaging according to claim 1 or 2, characterized in that the square root GMT of the product of the tensile strength DMDT in the MD direction and the tensile strength DCDT in the CD direction when the 2-ply or 3-ply paper towel sheet is 1730 cN / 76 mm or more and 7900 cN / 76 mm or less.

6. The smoothness (TS750) measured by a tissue softness measuring device (TSA) in the area of ​​the paper towel sheet where the embossed pattern is not applied is 20 dBV. ２ rms or higher, 130 dBV ２ A paper towel packaging according to claim 1 or 2, characterized in that it is less than or equal to rms.

7. [((Sheet length of the paper towel sheet) / 2) / √{(Dimension in the height direction Z of the package) ２ +(Dimension in the short side direction Y of the package) / 2} ２ The value calculated by] is 0.64 or more and 1.50 or less, and the paper towel package according to claim 1 or 2.

8. The paper towel packaging according to claim 1 or 2, characterized in that the value calculated by ((basis weight of the film × thickness of the film) / (mass of the paper towel sheet / 2)) is 380 or more and 7000 or less.

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