Paper towel packaging

Abstract

To provide a paper towel packaging that maintains the strength and absorbency of the paper towel sheet while suppressing slitting, tearing, and drop-back. [Solution] A paper towel package made by laminating paper towel sheets having an uneven pattern derived from the papermaking process and packaging them with film, wherein the basis weight of the sheets is 14 g / m². 2 More than 30g / m 2 The following applies to paper with a thickness of 0.15 mm to 0.45 mm and a water absorption rate of 70 g / m² per unit area. 2 More than 190g / m 2 The following conditions apply: water absorption per unit mass is between 2.5 g / g and 9.5 g / g; DMDT is between 1000 cN / 76 mm and 4000 cN / 76 mm; and the film basis weight is 20 g / m². 2 More than 75g / m 2 The following paper towel packaging is provided, having a thickness of 20 μm or more and 81 μm or less, and (slit length / longitudinal dimension of the clip) × 100 (%) being 50% or more and 145% 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] On the other hand, there is also demand for paper towels that are film-wrapped due to their 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 2 The following paper towel packaging is disclosed. [Prior art documents]

Patent Document

[0006]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, the paper towel obtained by the TAD papermaking technique has unevenness and is bulky, so the paper thickness per ply is high. In addition to the high paper thickness, generally, the paper towel contains a large amount of paper strength agent, so the strength of the sheet is also high.

[0008] Therefore, when manufacturing a package in which a paper towel obtained by the TAD papermaking technique is wrapped with a film, when pulling out the paper towel sheet, the load on the slit end at the outlet is large, so tearing occurs from the slit end. Also, when tearing occurs, it becomes difficult for the paper towel sheet to get caught on the slit, and dropout is likely to occur.

[0009] As such a method for preventing slit tearing, countermeasures such as 1. increasing the slit length, 2. thickening the film, and 3. reducing the strength of the sheet can be considered. However, in countermeasure 1, when the number of remaining sheets becomes small, dropout of the paper towel sheet is likely to occur. Also, in countermeasure 2, the shape retention of the film becomes high, and as a result, when the number of remaining sheets becomes small, the distance between the bottom surface and the top surface of the packaging bag formed by the film and the height difference from the clip become large, so dropout is likely to occur. And in countermeasure 3, the paper towel sheet is likely to break, resulting in poor usability. Note that as opposed to countermeasure 1 and countermeasure 2, if the slit is made shorter or the film is made thinner, there is a problem that the slit is likely to tear when the paper towel sheet is pulled out.

[0010] The present invention has been made in view of such circumstances, and in a paper towel package in which a paper towel sheet having an uneven pattern derived from a papermaking process is film-wrapped, it is an object to provide a paper towel package that suppresses slit tearing and drop-back while maintaining the strength and water absorption of the paper towel sheet.

Means for Solving the Problems

[0011] The inventor conducted intensive studies and laminated a single-ply paper towel sheet having an uneven pattern derived from a papermaking process different from an embossed pattern in a pop-up manner and film-wrapped it. In the paper towel package, the basis weight, paper thickness, water absorption per unit area and per unit mass, and the tensile strength DMDT in the MD direction of the paper towel sheet were defined, and the thickness of the film was defined. Furthermore, by defining the ratio of the length of the slit provided on the top surface of the package to the longitudinal dimension of the clip laminating the paper towel sheet, it was found that a paper towel package that suppresses slit tearing and drop-back while maintaining the strength and water absorption of the paper towel sheet can be obtained, and the present invention has been completed to solve the above problems. That is, the present invention provides the following.

[0012] (1) The first aspect of the present invention is a paper towel package in which a single-ply paper towel sheet having an uneven pattern derived from a papermaking process different from an embossed pattern is laminated in a pop-up manner and film-wrapped, 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 paper thickness in one ply is 0.15 mm or more and 0.45 mm or less, and the water absorption per unit area in one ply is 70 g / m 2 or more and 190 g / m 2Hereinafter, the water absorption per unit mass in one ply is 2.5 g / g or more and 9.5 g / g or less, the tensile strength DMDT in the MD direction during drying per one ply is 1000 cN / 76 mm or more and 4000 cN / 76 mm or less, the thickness of the film is 20 μm or more and 81 μm or less, and (the length of the slit provided on the top surface of the package / the longitudinal dimension of the clip laminated with the paper towel sheet) × 100 (%) is 50% or more and 145% or less. It is a paper towel package characterized by this.

[0013] (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 75 g / m 2 or less. It is characterized by this.

[0014] (3) The third aspect of the present invention is the paper towel package according to (1) or (2), wherein the tensile strength DCDT in the CD direction during drying per one ply of the paper towel sheet is 850 cN / 76 mm or more and 3900 cN / 76 mm or less. It is characterized by this.

[0015] (4) The fourth aspect of the present invention is the paper towel package according to (1) or (2), wherein GMT, which is the square root of the product of DMDT per one ply of the paper towel sheet and the tensile strength DCDT in the CD direction during drying per one ply, is 920 cN / 76 mm or more and 3950 cN / 76 mm or less. It is characterized by this.

[0016] (5) The fifth aspect of the present invention is the paper towel package according to (1) or (2), wherein the length of the slit is 120 mm or more and 300 mm or less. It is characterized by this.

[0017] (6) The sixth 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. It is characterized by this.

[0018] (7) A seventh aspect of the present invention is a paper towel packaging according to (1) or (2), wherein when the paper thickness of one ply of the paper towel sheet is A, and B is (length of the slit provided on the top surface of the packaging / longitudinal dimension of the clip on which the paper towel sheets are stacked) × 100 (%), the value calculated by (A / B) × 1000 is 1.8 or more and 5.0 or less.

[0019] (8) An eighth aspect of the present invention is a paper towel packaging as described in (7), characterized in that when the tensile strength DMDT in the MD direction per ply of the paper towel sheet at dry time is C, the value calculated by (A × C / B) is 2.0 or more and 19.0 or less.

[0020] (9) The ninth aspect of the present invention is a paper towel packaging according to (1) or (2), characterized in that the tear strength of the film in the MD direction is 0.1 N or more and 2.3 N or less.

[0021] (10) A tenth aspect of the present invention is a paper towel packaging according to (1) or (2), characterized in that the tear strength of the film in the CD direction is 2.3 N or more and 15.0 N or less. [Effects of the Invention]

[0022] According to the present invention, in a paper towel package in which a paper towel sheet having an uneven pattern derived from the papermaking process is film-wrapped, it is possible to provide a paper towel package that maintains the strength and water absorption of the paper towel sheet while suppressing slitting, tearing, and drop-back. [Brief explanation of the drawing]

[0023] [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 figure shows an example of an embossed pattern applied to a sheet in the paper towel packaging of the present invention. [Figure 4] This figure shows a method for measuring the water absorption capacity of a sheet in the paper towel packaging of the present invention. [Figure 5] This figure shows a part of the papermaking process for the paper towel packaging of the present invention. [Modes for carrying out the invention]

[0024] The embodiments for carrying out the present invention will be described in detail below with reference to the drawings, but these are provided for illustrative purposes only and do not limit the present invention.

[0025] In the drawings, identical elements will be denoted by the same reference numeral, and redundant explanations will be omitted. Furthermore, unless otherwise specified, positional relationships such as top, bottom, left, and right shall be based on those shown in the drawings. Additionally, the dimensional ratios in the drawings are not limited to those shown. Furthermore, in this specification, the MD direction refers to the manufacturing direction (machine direction, also called the flow direction) during the production of paper towel sheets or films. The CD direction is the direction perpendicular to the MD direction (cross direction, also called the width direction), and is also called the TD direction (transverse direction).

[0026] <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 single-ply paper towel sheets 10 having a different uneven pattern 23 (see Figure 3) derived from the papermaking process than the embossed pattern 20 (see Figure 3), in a pop-up manner, and packaging them with a film 2. Preferably, 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).

[0027] As shown in Figure 1, the paper towel packaging 1 has a slit 3 on its 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 and 300 mm or less. If the length SL is less than 120 mm, and the longitudinal dimension PL of the clip (described later) does not change, the slit is more likely to tear when the paper towel sheet 10 is pulled out, and it is also more likely to drop back. If the length SL exceeds 300 mm, and the longitudinal dimension PL of the clip (described later) does not change, the paper towel sheet 10 is less likely to catch in the slit 3, making it more likely to drop back.

[0028] The length SL of the slit 3 is more preferably 140 mm or more at the lower limit, and even more preferably 160 mm or more. The upper limit is more preferably 275 mm or less, and even more preferably 255 mm or less. The slit 3 provided in this case may be formed only on the top surface of the packaging 1, or it may be formed continuously on the side surface of the packaging 1. In this case, the length SL of the slit 3 formed on the top surface of the packaging 1 is measured from the slit portion formed on the top surface of the packaging 1 to the slit portion that continues to the side surface. Furthermore, while it is preferable that the slit 3 be approximately straight as shown in Figure 2(a), it may also be shaped such that the start and end 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).

[0029] In the packaging body 1, the longitudinal dimension (i.e., the sheet width of the paper towel sheet 10) PL of the laminate (hereinafter also referred to as the clip) formed by laminating paper towel sheets 10 wrapped in film 2 is preferably 100 mm or more at the lower limit, more preferably 130 mm or more, and even more preferably 150 mm or more. Furthermore, 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 longitudinal dimension PL is less than 100 mm, and the length SL of the slit 3 does not change, the paper towel sheet 10 will not easily catch in the slit 3, making it more likely to drop back. If the longitudinal dimension PL exceeds 290 mm, and the length SL of the slit 3 does not change, the slit is more likely to tear when the paper towel sheet 10 is pulled out, and at the same time, it will also be 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."

[0030] Furthermore, the ratio (length SL of the slit 3 provided on the top surface of the packaging 1 / length PL of the clip with the stacked paper towel sheets 10) × 100 (%) is between 50% and 145%. If the ratio is less than 50%, the length SL of the slit 3 is shorter than the length PL of the clip, making it easier for the slit to tear when the paper towel sheet 10 is pulled out, and also making it easier for the sheet to drop back. If the ratio exceeds 145%, the length SL of the slit 3 is longer than the length PL of the clip, making it difficult for the paper towel sheet 10 to catch on the slit 3, and thus making it easier for the sheet to drop back. Furthermore, the ratio (length SL of the slit 3 provided on the top surface of the packaging 1 / length PL of the clip formed by stacking paper towel sheets 10) × 100 (%) is preferably 60% or more at the lower limit, and more preferably 70% or more. The upper limit is preferably 135% or less, and more preferably 125% or less.

[0031] The dimension PW in the short-side direction of the clip is not particularly limited, but the lower limit 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 150 mm or less, more preferably 145 mm or less, and even more preferably 140 mm or less. If the dimension PW of the clip in the short side direction is less than 65 mm, the sheet length will be shorter, and as the number of paper towel sheets 10 decreases, the "length coming out of the slit" of the paper towel sheets 10 that are pulled out will be shorter, making them more prone to dropping back. If the dimension PW of the clip in the short side direction exceeds 150 mm, the sheet length will be longer, and when the paper towel sheets 10 are pulled out, the area that puts stress on the slit 3 will increase, making the slit more prone to tearing and also making them more prone to dropping back.

[0032] Furthermore, while the clip height PH is not particularly limited, it is preferable that the lower limit be 40 mm or more, more preferably 50 mm or more, and even more preferably 60 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 PH is less than 40 mm, and the number of sheets of paper towel 10 remains the same, the basis weight of the paper towel 10 will decrease, resulting in lower strength and making it more prone to tearing. If the height PH exceeds 150 mm, and the number of sheets of paper towel 10 remains the same, the basis weight and paper thickness of the paper towel 10 will increase, making it more prone to slitting and dropback. The dimensions of the clip in each direction are determined by measuring two points using a ruler and taking the average of those measurements.

[0033] Furthermore, the lower limit of the clip's mass is preferably 100g or more, more preferably 110g or more, and even more preferably 120g or more. The upper limit is preferably 230g or less, more preferably 210g or less, and even more preferably 200g or less. If the mass is less than 100g, and the number of sheets of paper towel 10 and the dimensions in each direction remain unchanged, the basis weight will be lower, resulting in lower sheet strength and making it more prone to tearing. If the mass exceeds 230g, and the number of sheets of paper towel 10 and the dimensions in each direction remain unchanged, the basis weight will be higher, resulting in excessively high sheet strength, making it more likely for slit tears to occur when the paper towel 10 is pulled out, and also making it more prone to dropback.

[0034] Furthermore, the number of paper towel sheets 10 contained in the clip is preferably at a minimum of 80 sets, more preferably at 90 sets, and even more preferably at 100 sets. The upper limit is preferably 250 sets or less, more preferably 225 sets or less, and even more preferably 200 sets or less. If the number of sets is less than 80, the water absorption per pack of the packaging 1 will be low. If the number of sets exceeds 250, as the number of remaining sets decreases, the difference in height between the bottom and top of the packaging bag formed by the film 2 and the clip becomes large, making dropback more likely.

[0035] (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 2 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.

[0036] 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.

[0037] Furthermore, the ash content of film 2 is preferably 1.5% to 12.0%, more preferably 2.0% to 10.0%, and even more preferably 2.5% to 8.0%. By keeping the ash content of film 2 within the above numerical range, a package 1 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. Note that in measuring ash content, the oven-dry mass of the test specimen is not measured directly; instead, the mass of the film 2 test specimen after conditioning at 23°C and 50% humidity is considered the oven-dry mass.

[0038] 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 contacts the clip or on the surface that comes into contact with the outside air, and may consist of one layer or two or more layers.

[0039] The basis weight of film 2 is 20 g / m². 2 More than 75g / m 2 Preferably, the basis weight of film 2 is 20 g / m². 2 If the basis weight is less than 75 g / m², slit tearing is more likely to occur when pulling out the paper towel sheet 10, and it is also more likely to drop back. 2Beyond a certain point, film 2 becomes thicker and its shape retention improves. As the number of remaining sheets decreases, the difference in height between the bottom and top of the packaging bag formed by film 2 and the clip increases, making it more prone to dropping back. Note that the lower limit of the basis weight of film 2 is 25 g / m². 2 It is more preferable that the amount be greater than or equal to 35 g / m 2 It is even more preferable that the value be greater than or equal to the above. Furthermore, the upper limit is 65 g / m². 2 It is more preferable that the following conditions apply: 55 g / m 2 The following is even more preferable: The basis weight of film 2 is measured in accordance with JIS P 8124.

[0040] Furthermore, the thickness of film 2 is between 20 μm and 81 μm. If the thickness of film 2 is less than 20 μm, slitting is more likely to occur when the paper towel sheet 10 is pulled out, and at the same time, dropback is also more likely. If the thickness of film 2 exceeds 81 μm, the shape retention is improved, so when the number of remaining sheets decreases, the difference in height between the bottom and top of the packaging bag formed by film 2 and the clip becomes larger, making dropback more likely. The thickness of film 2 is preferably 29 μm or more at the lower limit, and more preferably 38 μm or more. The upper limit is preferably 68 μm or less, and more preferably 59 μm or less. The thickness of film 2 is measured in accordance with JIS K 7130.

[0041] Furthermore, it is preferable that the tear strength of film 2 in the MD direction be between 0.1N and 2.3N. Also, it is preferable that the tear strength of film 2 in the CD direction be between 2.3N and 15.0N. If the tear strength of film 2 in the MD direction is less than 0.1N, or if the tear strength of film 2 in the CD direction is less than 2.3N, slitting is more likely to occur when the paper towel sheet 10 is pulled out, and it will also be more prone to dropping back. If the tear strength of film 2 in the MD direction exceeds 2.3N, or if the tear strength of film 2 in the CD direction exceeds 15.0N, the strength of film 2 increases, improving its shape retention, which makes it more prone to dropping back when the number of remaining sheets decreases. In the packaging 1 of this embodiment, by setting the tear strength of the film 2 in the MD direction and the tear strength in the CD direction to within the above numerical range, slit tearing and dropback can be suppressed. In particular, by setting the tear strength in the CD direction to within the above numerical range, the film 2 becomes less likely to tear in caramel packaging because the CD direction is aligned with the slit 3. As a result, caramel packaging can be selected as a particularly suitable packaging form in the packaging forms described later.

[0042] Furthermore, the tear strength of film 2 in the MD direction is more preferably 0.4 N or higher at the lower limit, and even more preferably 0.7 N or higher. The upper limit is more preferably 1.9 N or lower, and even more preferably 1.6 N or lower. Furthermore, the tear strength of film 2 in the CD direction is more preferably 3.6 N or higher at the lower limit, and even more preferably 5.0 N or higher. The upper limit is more preferably 13.0 N or lower, and even more preferably 10.0 N or lower. The tear strength of film 2 in each direction is measured according to JIS K 7128.

[0043] <Paper towel sheets> Although the paper towel sheet 10 in this embodiment is 1-ply, if the paper towel sheet 10 is 2-ply or more, the strength per product ply of the paper towel sheet 10 will increase as a result, making it easier for slitting and tearing to occur when the paper towel sheet 10 is pulled out, and also making it easier for it to drop back. In this embodiment, the paper towel sheet 10 preferably contains wet pulp. Furthermore, it is preferable that the wet pulp content is 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. There is no particular upper limit set for the wet pulp content, but if it is too high, the strength of the paper towel sheet 10 tends to increase, which may cause slitting or dropback when the paper towel sheet 10 is pulled out. 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.

[0044] 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 strength of the paper towel sheet 10 will be low and it will tear easily. If the mass ratio of LBKP is too high, the strength of the paper towel sheet 10 will be low and it will tear easily. 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.

[0045] 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.

[0046] (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 strength of the paper towel sheet 10 will be reduced and it will tear easily. 2 If this limit is exceeded, the strength of the paper towel sheet 10 becomes too high, making it more likely for the slit to tear when the paper towel sheet 10 is pulled out, and also making it more likely to drop back. The basis weight per ply of the paper towel sheet 10 has a minimum value of 16 g / m². 2 Preferably, it is 17 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.

[0047] (paper thickness) Furthermore, the paper thickness of each ply of the paper towel sheet 10 is between 0.15 mm and 0.45 mm. If the paper thickness is less than 0.15 mm, the specific volume will be lower, resulting in poorer water absorption, even if the basis weight of the paper towel sheet 10 remains the same. If the paper thickness exceeds 0.45 mm, the load on the slit 3 increases, making it more likely for the slit to tear when the paper towel sheet 10 is pulled out, and also making it more likely for the sheet to drop back. Furthermore, the paper thickness of one ply of the paper towel sheet 10 is preferably 0.19 mm or more at the lower limit, and more preferably 0.22 mm or more. The upper limit is preferably 0.43 mm or less, and more preferably 0.41 mm or less.

[0048] 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. For the sample, 10 sets of 1-ply paper towel sheets 10 are stacked and measured as 10 plies. The measurement is repeated 10 times at different locations (not 10 times at the same location, but 10 different locations), and the average of the measurement results is converted to a single-ply value to determine the final paper towel sheet 10 thickness.

[0049] (Sheet length) Furthermore, the minimum length of the paper towel sheet 10 is preferably 130 mm or more, more preferably 140 mm or more, and even more preferably 150 mm or more. The maximum length is preferably 300 mm or less, more preferably 290 mm or less, and even more preferably 280 mm or less. If the sheet length is less than 130 mm, the water absorption per sheet of the paper towel sheet 10 will be inferior. If the sheet length exceeds 300 mm, when pulling out the paper towel sheet 10, the increased sheet length increases the area of ​​load on the slit 3, making it more likely for the slit to tear and also more likely for the sheet to drop back.

[0050] (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. 3 If the amount is less than / g, the paper towel sheet 10 will have poor water absorption. Also, the specific volume of the paper towel sheet 10 is 23cm³. 3 If the amount exceeds / g, and the basis weight of the paper towel sheet 10 remains unchanged, the paper thickness will increase instead. As a result, the load on the slit will increase when the paper towel sheet 10 is pulled out, making it more prone to tearing at the slit and also more prone to dropback. 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 22 cm or more. The upper limit is 22 cm. 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, and the volume per unit (g) (cm³). 3 It is represented as ).

[0051] (DMDT and DCDT) The Dry Machine Direction Tensile Strength (DMDT) per ply of the paper towel sheet 10 in the MD direction during dry conditions is between 1000 cN / 76 mm and 4000 cN / 76 mm. If the DMDT is less than 1000 cN / 76 mm, the strength of the paper towel sheet 10 will be low and it will tear easily. If the DMDT exceeds 4000 cN / 76 mm, the strength of the paper towel sheet 10 will be too high, making it more prone to slitting when the paper towel sheet 10 is pulled out, and also more prone to dropback. Furthermore, the DMDT per ply of the paper towel sheet 10 is preferably 1200 cN / 76 mm or more at the lower limit, and more preferably 1400 cN / 76 mm or more. The upper limit is preferably 3550 cN / 76 mm or less, and more preferably 3400 cN / 76 mm or less.

[0052] Furthermore, the Dry Cross Direction Tensile Strength (DCDT) per ply of the paper towel sheet 10 in the CD direction when dry is preferably 850 cN / 76 mm or more and 3900 cN / 76 mm or less. If the DCDT is less than 850 cN / 76 mm, the strength of the paper towel sheet 10 will be low and it will tear easily. If the DCDT exceeds 3900 cN / 76 mm, the strength of the paper towel sheet 10 will be too high, making it easy for slit tears to occur when the paper towel sheet 10 is pulled out, and also making it easier for it to drop back. Furthermore, the DCDT per ply of the paper towel sheet 10 is more preferably 950 cN / 76 mm or more at the lower limit, and even more preferably 1100 cN / 76 mm or more. The upper limit is more preferably 3175 cN / 76 mm or less, and even more preferably 2950 cN / 76 mm or less.

[0053] Furthermore, the Geometric Tensile Strength (GMT), which is the square root of the product of DMDT and DCDT per ply, is preferably between 920 cN / 76 mm and 3950 cN / 76 mm. If the GMT is less than 920 cN / 76 mm, the strength of the paper towel sheet 10 will be low and it will tear easily. If the GMT exceeds 3950 cN / 76 mm, the strength of the paper towel sheet 10 will be too high, making it more prone to slitting when the paper towel sheet 10 is pulled out, and also more prone to dropback. Furthermore, the GMT, which is the square root of the product of DMDT and DCDT per ply, is more preferably 1070 cN / 76 mm or more at the lower limit, and even more preferably 1240 cN / 76 mm or more. The upper limit is more preferably 3360 cN / 76 mm or less, and even more preferably 3200 cN / 76 mm or less.

[0054] The DMDT and DCDT per ply of the paper towel sheet 10 are measured in accordance with JIS P 8113. GMT is calculated as the square root of the product of their tensile strengths.

[0055] Furthermore, if the paper thickness of one ply of the paper towel sheet 10 is A, and B is (length SL of the slit 3 provided on the top surface of the packaging body 1 / length PL of the clip on which the paper towel sheets 10 are stacked) × 100 (%), then it is preferable that the value calculated by (A / B) × 1000 be between 1.8 and 5.0. If the value is less than 1.8, the paper towel sheet 10 is more likely to drop back if the length SL of the slit 3 is longer than the length PL of the clip on which the paper towel sheets 10 are stacked, and if the paper thickness of the paper towel sheet 10 is low, the specific volume will be low as a result, resulting in poor water absorption. If the value exceeds 5.0, when the paper towel sheet 10 is pulled out, the load on the slit 3 increases, making it more likely for the slit to tear, and at the same time, it is more likely for the paper towel sheet 10 to drop back. Furthermore, the value calculated by (A / B) × 1000 is more preferably lower than 2.2, and even more preferably lower than 2.4. The upper limit is more preferably 4.8 or less, and even more preferably 4.5 or less.

[0056] Furthermore, in relation to the above values, if C is the tensile strength DMDT in the MD direction per ply of the paper towel sheet 10 when dry, it is preferable that the value calculated by (A × C / B) be between 2.0 and 19.0. If the value is less than 2.0, the paper towel sheet 10 is more likely to drop back if the length SL of the slit 3 is long relative to the longitudinal dimension PL of the clip in which the paper towel sheets 10 are laminated, and it is more likely to tear if the strength of the paper towel sheet 10 is low. Also, if the paper thickness of the paper towel sheet 10 is low, the specific volume will be low as a result, resulting in poor water absorption. If the value exceeds 19.0, the load on the slit 3 will be large when the paper towel sheet 10 is pulled out, making it more likely for the slit to tear and simultaneously more likely for it to drop back. Furthermore, the value calculated by (A × C / B) is more preferably lower than 2.7, and even more preferably 3.5. The upper limit is more preferably 17.0 or less, and even more preferably 15.0 or less.

[0057] (Embossed) The paper towel sheet 10 included in the packaging 1 of this embodiment is preferably embossed, and preferably has an embossed pattern 20. The embossing also includes heat embossing using matched steel (steel match).

[0058] It is preferable that the paper towel sheet 10 has an embossed pattern 20, but it is not necessary. If the paper towel sheet 10 has an embossed pattern 20, the water absorption of the paper towel sheet 10 will be good.

[0059] Figure 3 shows an example of an embossed pattern 20 applied to the paper towel sheet 10 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.

[0060] The continuous embossing 21 is not particularly limited in its overall shape, but it is preferable that it has a structure in which straight lines and curves are repeated over 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. The continuous embossing 21 may be continuous as a whole pattern, but the straight lines and curves that form the embossing do not have to be continuous within the pattern and may be interrupted. Preferably, the entire pattern is not continuous. In addition, 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.

[0061] 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 will not be able to 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.

[0062] 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%)

[0063] (Water absorption) The water absorption capacity per unit area of ​​one ply of the paper towel sheet 10 is 70 g / m². 2 More than 190g / m 2 The following applies: Water absorption per unit area is 70 g / m². 2 If the amount is less than 190 g / m², the paper towel sheet 10 will have poor water absorption. 2 If it exceeds this limit, and the basis weight of the paper towel sheet 10 remains unchanged, the specific volume will increase instead, resulting in a higher paper thickness. Consequently, when the paper towel sheet 10 is pulled out, the load on the slit 3 increases, making it more likely for the slit to tear, and simultaneously making it more likely for the paper towel sheet to drop back. Furthermore, the minimum water absorption per unit area of ​​one ply of the paper towel sheet 10 is 80 g / m². 2 Preferably, it should be 90 g / m² or more. 2 It is more preferable that the value be greater than or equal to the above. Furthermore, the upper limit is 180 g / m².2 Preferably, it is 170 g / m² 2 The following is more preferable:

[0064] Furthermore, the water absorption per unit mass of one ply of the paper towel sheet 10 is between 2.5 g / g and 9.5 g / g. If the water absorption per unit mass is less than 2.5 g / g, the paper towel sheet 10 has poor water absorption. If the water absorption per unit mass exceeds 9.5 g / g, and the basis weight of the paper towel sheet 10 remains unchanged, the specific volume increases and the paper thickness increases. As a result, when the paper towel sheet 10 is pulled out, the load on the slit 3 increases, making it more likely for the slit to tear, and simultaneously making it more likely for the sheet to drop back. Furthermore, the water absorption per unit mass of one ply of the paper towel sheet 10 is preferably 3.5 g / g or more at the lower limit, and more preferably 4.5 g / g or more. The upper limit is preferably 8.5 g / g or less, and more preferably 7.5 g / g or less.

[0065] The method for measuring the water absorption capacity of each paper towel sheet 10 is explained below, with reference to Figure 4. First, a single-ply paper towel sheet 10 is taken and cut using a 7.6 cm square template to create a rectangular test piece 30 with sides of 7.6 cm. 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).

[0066] 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 4, 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.

[0067] 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 one 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. 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.

[0068] <Manufacturing method for paper towel packaging> There are no particular limitations 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 manufacturing methods include, for example, the steps of (1) papermaking and creping, (2) embossing, (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.

[0069] Furthermore, since a single-ply product such as the paper towel sheet 10 according to this embodiment has a difference in smoothness between the front and back sides, calendering may be performed to reduce this difference. Furthermore, when performing the calendaring process, it is preferable to do so before (2) embossing.

[0070] In this process, during the papermaking process, a different uneven pattern 23, derived from the papermaking process (fabric) and distinct from the embossed pattern 20 described above, is applied to the paper towel sheet 10. If this uneven pattern 23 is not present, the paper towel sheet 10 will have poor water absorption.

[0071] 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 5, 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.

[0072] 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 5, 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.

[0073] Furthermore, the textured pattern 23 can be changed as needed by changing the fabric pattern (fine pattern, coarse pattern). Changing the textured pattern 23 will change the specific volume (paper thickness), but it is preferable to select a pattern such that the specific volume falls within the numerical range described above.

[0074] As described above, according to this embodiment, in a paper towel package in which a paper towel sheet having an uneven pattern derived from the papermaking process is film-wrapped, it is possible to provide a paper towel package that maintains the strength and water absorption of the paper towel sheet while suppressing slitting, tearing, and drop-back.

[0075] 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]

[0076] 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.

[0077] Under the conditions shown in Tables 3 and 4, paper towel (kitchen towel) packaging for Examples 1-19 and Comparative Examples 1-6 was prepared using caramel packaging, 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. The following evaluations were all conducted using a four-point system from 1 to 4, with 1 point being a fail and 2 points or higher being a pass.

[0078] (The sheet's resistance to tearing) The tear resistance of paper towel sheets in paper towel packaging was evaluated using the DMDT (Damage-Free Durability) of one ply of the paper towel sheet, and the evaluation was categorized into four levels based on the DMDT value. The evaluation criteria are shown in Table 1 below. [Table 1]

[0079] (Water absorption of the sheet) The water absorption of paper towel sheets in paper towel packaging was evaluated based on the amount of water absorbed per unit area and per unit mass of each ply of paper towel sheet. The evaluation was then categorized into four levels based on these values. The evaluation criteria are shown in Table 2 below. [Table 2]

[0080] (Difficulty of the seat dropping back) The resistance to sheet drop-back in paper towel packaging was evaluated on a four-point scale based on the value of [total number of times sheets were dropped / total number of sets in 3 packs] × 100 (%) when all sheets were pulled out from 3 packs of packaging. The evaluation criteria are as follows: 4 points: Value is less than 5% 3 points: Value is between 5% and less than 8% 2 points: Value is between 8% and less than 10% 1 point: Value is 10% or more

[0081] [Table 3]

[0082] [Table 4]

[0083] As is clear from the results shown in Tables 3 and 4, the packaging of Examples 1 to 19 all had paper towel sheets that were resistant to tearing, had excellent water absorption, and were resistant to drop-back. In contrast, Comparative Examples 1 to 6 were all inferior in either tear resistance, water absorption, or drop-back of the paper towel sheets.

[0084] Based on the above, it has been confirmed that, according to this embodiment, a paper towel package in which a paper towel sheet having an uneven pattern derived from the papermaking process is film-wrapped can be provided that maintains the strength and water absorption of the paper towel sheet while suppressing slitting, tearing, and drop-back. [Explanation of Symbols]

[0085] 1 (Paper towel) packaging 2 films 3 slits 10 paper towel sheets 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 is formed by laminating single-ply paper towel sheets, each having an uneven pattern derived from the papermaking process different from an embossed pattern, in a pop-up manner, and then packaging them in film. The basis weight per ply of the aforementioned paper towel sheet is 14 g / m². ２ 30g / m or more ２ The following specifications apply: paper thickness per ply is 0.15 mm to 0.45 mm, and water absorption per unit area per ply is 70 g / m². ２ 190g / m or more ２ The following conditions apply: the water absorption per unit mass per ply is 2.5 g / g or more and 9.5 g / g or less; the tensile strength (DMDT) in the MD direction per ply when dry is 1000 cN / 76 mm or more and 4000 cN / 76 mm or less. The thickness of the aforementioned film is 20 μm or more and 81 μm or less. A paper towel packaging characterized in that (length of the slit provided on the top surface of the packaging / longitudinal dimension of the clip on which the paper towel sheets are stacked) × 100 (%) is 50% or more and 145% or less.

2. The basis weight of the aforementioned film is 20 g / m². ２ 75g / 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 tensile strength DCDT in the CD direction per ply of the paper towel sheet when dry is 850 cN / 76 mm or more and 3900 cN / 76 mm or less.

4. The paper towel packaging according to claim 1 or 2, characterized in that the GMT, which is the square root of the product of the DMDT per ply of the paper towel sheet and the DCDT (tensile strength in the CD direction per ply when dry), is 920 cN / 76 mm or more and 3950 cN / 76 mm or less.

5. The paper towel packaging according to claim 1 or 2, characterized in that the length of the slit is 120 mm or more and 300 mm or less.

6. 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.

7. The paper towel packaging according to claim 1 or 2, characterized in that when the paper thickness of one ply of the paper towel sheet is A, and B is (length of the slit provided on the top surface of the packaging / longitudinal dimension of the clip on which the paper towel sheets are stacked) × 100 (%), the value calculated by (A / B) × 1000 is 1.8 or more and 5.0 or less.

8. The paper towel packaging according to claim 7, characterized in that, when C is the tensile strength DMDT in the MD direction per ply of the paper towel sheet when dry, the value calculated by (A × C / B) is 2.0 or more and 19.0 or less.

9. The paper towel packaging according to claim 1 or 2, characterized in that the tear strength of the film in the MD direction is 0.1 N or more and 2.3 N or less.

10. The paper towel packaging according to claim 1 or 2, characterized in that the tear strength of the film in the CD direction is 2.3 N or more and 15.0 N or less.

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