JP7545815B2 - Toilet roll packaging - Google Patents

Description

The present invention relates to a toilet roll packaging body suitable for packaging paper products, particularly toilet rolls.

Conventionally, packages are known that contain rolled paper products such as toilet paper and kitchen paper, and layered paper products such as tissue paper and wipes as packaged items.

For example, Patent Document 1 discloses a package for wrapping rolled paper products, in which a gusset is folded symmetrically into a cylindrical film such as polyethylene to form a main body, and the top of the main body is folded flat to form a handle.

On the other hand, paper cartons made of high-weight paperboard are commonly used as packaging for layered paper products. As an alternative to paper cartons, for example, Patent Document 2 discloses a film packaging body in which a perforation is provided in the center of the top surface of a packaging bag made of a flexible resin film.

JP 2004-269010 A JP 2016-188092 A

However, with the growing awareness of environmental issues in recent years, there is a desire to reduce the use of plastics (synthetic resins). For example, copy paper is packaged in a packaging base material mainly made of paper, but in the case of toilet paper, especially toilet rolls in roll form, toilet rolls are soft and their shape is not stable, so when packaging, the packaging base material bends in unintended places, resulting in poor shape after packaging. Also, because paper is thicker and stiffer than film, it is difficult for the paper to bend in the desired places, similarly resulting in poor shape after packaging.

As shown in FIG. 4(a), tightly winding the toilet paper makes it easier to wrap, but after wrapping, the portion of the packaging base material 20 that does not come into contact with the toilet roll 21 (loose portion 20s) tends to be taut, making the packaging base material 20 more likely to tear when the package is held. Therefore, loosening the loose portion 20s prevents tearing, but the circumference of the packaging base material 20 relative to the toilet roll 21 becomes larger (longer), making it appear loose and resulting in an inferior shape after wrapping. Also, loosening the packaging base material 20 can cause it to bend in unintended places during wrapping, resulting in an inferior shape after wrapping.

On the other hand, as shown in FIG. 4(b), if the toilet paper is wrapped loosely, the toilet roll 31 is easily crushed after wrapping, and the loosened portion 30s of the packaging base material 30 becomes shorter and more likely to slacken, making it less likely to tear, but as mentioned above, the shape after wrapping is inferior in the first place. Therefore, if the paper basis weight is reduced so that the packaging base material 30 is more likely to bend, then the packaging base material 30 will be more likely to tear.

As described above, if the product loses its shape after packaging or becomes easily torn, the product may become the subject of complaints or may become unsellable in retail stores.
As described above, it has been difficult to package toilet rolls with a packaging base material mainly made of paper using conventional techniques.

The present invention was made in consideration of these circumstances, and its purpose is to provide a toilet roll package that maintains a good shape after packaging and is less likely to tear, even when the toilet roll is packaged in a packaging base material mainly made of paper.

The inventors of the present invention have conducted intensive research in view of the above problems. As a result, they have found that by specifying the basis weight and burst strength of the packaging substrate, the roll density of the toilet roll, and the slack in the circumferential direction of the packaging substrate in a packaged state, and further specifying the ratio of the roll density and the slack in the circumferential direction, it is possible to obtain a toilet roll package that has a good shape after packaging and is difficult to tear in the packaging substrate even when the toilet roll is packaged in a packaging substrate mainly made of paper, thereby solving the above problems, and have completed the present invention.
Specifically, the present invention provides the following:

(1) A first aspect of the present invention is a toilet roll package in which 2, 4, or 6 toilet rolls are packaged with a packaging base material including at least a paper base material, the packaging base material having a basis weight of 30 g/ ^m2 or more and 105 g/ ^m2 or less and a burst strength of 65 kPa or more and 295 kPa or less, the toilet rolls are arranged in two or three rows perpendicular to the axial direction, and both end faces of each row are aligned, the roll density of the toilet rolls is 0.1 g/ ^cm3 or more and 0.33 g/ ^cm3 or less, the slack in the circumferential direction of the packaging base material in a packaged state of the toilet rolls is 4 mm or more and 38 mm or less, and the ratio (B/A) of the slack in the circumferential direction (B) to the roll density (A) is 13 or more and 200 or less.
(2) A second aspect of the present invention is the toilet roll packaging according to (1), characterized in that the bending stiffness of the packaging base material in the CD direction is 8 μN·m or more and 130 μN·m or less.
(3) A third aspect of the present invention is the toilet roll packaging according to (1) or (2), characterized in that the bending stiffness of the packaging base material in the MD direction is 18 μN·m or more and 300 μN·m or less.
(4) A fourth aspect of the present invention is the toilet roll packaging body according to any one of (1) to (3), characterized in that the ratio (%) of the basis weight of the paper base material to the basis weight of the packaging base material is 51% or more and 100% or less.
(5) A fifth aspect of the present invention is the toilet roll packaging according to any one of (1) to (4), characterized in that the packaging is a caramel packaging.

According to the present invention, it is possible to provide a toilet roll package that maintains a good shape after packaging and is resistant to tearing of the packaging base material, even when the toilet roll is packaged in a packaging base material mainly made of paper.

FIG. 1 is a perspective view showing an example of a toilet roll packaging body of the present invention. FIG. 2 is a diagram showing a method for measuring the slack in the circumferential length of the toilet roll packaging of the present invention. FIG. 2 is a perspective view showing an example of an arrangement of toilet rolls packaged in the toilet roll packaging of the present invention. FIG. 1 is a plan view showing an example of a conventional toilet roll packaging body.

The following describes in detail the form for carrying out the present invention (hereinafter, "embodiment") with reference to the drawings. However, these are presented for illustrative purposes and are not intended to limit the present invention.

1. Toilet roll package Fig. 1 is a perspective view showing an example of the toilet roll package of the present invention (hereinafter, also simply referred to as "package"). As shown in Fig. 1, the package 1 of the present invention packages two, four or six toilet rolls 11 (four in Fig. 1) with a packaging substrate 10 including at least a paper substrate. In the package 1, the packaging substrate 10 may cover only a part of the toilet roll 11 rather than the entirety, and the toilet roll 11 may not be sealed (not shown).

Here, when the toilet roll 11 becomes longer in winding length (described later) and the weight of the roll increases, when the package 1 is held from both sides with one hand, finger pressure is applied to the circumferential direction P of the packaging substrate 10, making the packaging substrate 10 more likely to tear from the loosened portion 10s. On the other hand, if the packaging substrate 10 is wrapped too loosely, the loosened portion 10s of the packaging substrate 10 will loosen, resulting in a poor shape after packaging. Therefore, by specifying the degree of looseness of the packaging substrate 10 in the circumferential direction P, a package 1 can be obtained that has a good shape after packaging and in which the packaging substrate 10 is less likely to tear.

The slack in the circumferential direction P of the packaging substrate 10 is measured as shown in FIG.
First, the packaging body 1 is placed so that the axial direction L of the toilet rolls 11 is horizontal, and a stainless steel first ruler S having a mass of 64 g, a thickness of 1 mm, a width of 25 mm and a scale length of 300 mm is placed across two rows (four in Figures 1 and 3(c)) of toilet rolls 11 adjacent in the horizontal direction (i.e., perpendicular to the axial direction L) and placed so that its plate surface is in contact with the packaging substrate 10, and the surface (line) of the first ruler S that is in contact with the packaging substrate 10 is designated as the reference line SL.
Next, in the slack portion 10s of the packaging substrate 10 that is packaged across two laterally adjacent rows (four in Figures 1 and 3(c)), a stainless steel second ruler R having a mass of 10 g, a thickness of 0.5 mm, a width of 15 mm and a scale length of 150 mm is placed approximately in the center between the toilet rolls 11 in each row, so that the thickness direction Rt of the second ruler R is parallel to the end face of the toilet roll 11 (i.e., perpendicular to the axial direction L), and the distance (sinking amount) D from the reference line SL to the tip of the second ruler R is measured.

The distance D is measured at positions 25% from both ends of the height h of the packaging body 1 and at three central positions (three measurement points m in FIG. 1 ). Measurements are also taken on the front and back of one packaging body 1. This is done for five packaging bodies 1, and the values of the distance D at a total of 30 positions are averaged and used as the slack in the circumferential direction P of the packaging substrate 10.
As the first ruler S and the second ruler R, for example, the "Silver Ruler" manufactured by Shinwa Measurement Co., Ltd. can be used.

The slackness in the circumferential direction P of the packaging substrate 10 measured in this manner is 4 mm or more and 38 mm or less, preferably 6 mm or more and 28 mm or less, and more preferably 8 mm or more and 20 mm or less. If the slackness in the circumferential direction P is less than 4 mm, the portion of the packaging substrate 10 that is not in contact with the toilet roll 11 (slack portion 10s) is likely to be in a taut state, and the packaging substrate 10 is likely to tear when the package 1 is held. If the slackness in the circumferential direction P exceeds 38 mm, the circumference of the packaging substrate 10 relative to the toilet roll 11 becomes large (long), and the packaging substrate 10 bends in unintended places during packaging, resulting in a poor shape after packaging.

The packaging body 1 may also have perforations to make it easier to tear and open the packaging base material 10 (not shown). For example, the perforations may be provided parallel to the axial direction L in the loosened portion 10s, or parallel to the axial direction L in the waist portion of the packaging body 1 other than the loosened portion 10s (not shown). The perforations may also be provided perpendicular to the axial direction L, for example, on the top or bottom surface of the packaging body 1, perpendicular to the axial direction L, and in a direction connecting the centers of the axes of the toilet rolls 11 arranged in two or three rows (not shown). Furthermore, the perforations may be provided on the waist portion of the packaging body 1 in a direction perpendicular to the axial direction L and along the circumferential direction P of the packaging base material 10 (not shown). The length of the perforations can be freely set.

2. Packaging Substrate The packaging substrate 10 includes at least a paper substrate, but may include other layers. When the paper substrate is formed into the packaging body 1, printing may be applied to the outer surface side. In addition, the paper substrate may be an overcoated paper that is overcoated to ensure waterproofing.

The basis weight of the packaging substrate 10 (for example, the total basis weight of the paper substrate and the seal layer) is 30 g/m ² or more and 105 g/m ² or less, preferably 40 g/m ² or more and 85 g/m ² or less, and more preferably 50 g/m ² or more and 75 g/m ² or less. When the basis weight of the packaging substrate 10 is within the above range, the packaging substrate 10 is less likely to break and is easily bent at a predetermined position during packaging, and a package 1 having excellent shape after packaging can be obtained. The basis weight of the packaging substrate can be measured in accordance with JIS P 8124.

(1) Paper Base The paper base is produced using wood pulp as the main raw material. The pulp used here may be any of the conventionally known pulps, such as softwood kraft pulp, hardwood kraft pulp, groundwood pulp, thermomechanical pulp, chemi-thermomechanical pulp, and recycled paper pulp used in newspapers, flyers, rough magazines, coated magazines, thermal recording paper, pressure-sensitive recording paper, imitation paper, colored wood-free paper, copy paper, computer output paper, or a mixture of these recycled paper, either alone or in any mixture ratio.

In the paper base material of the packaging body 1 of the present invention, the pulp used is preferably 30 to 100% by weight of softwood kraft pulp and 0 to 70% by weight of hardwood kraft pulp, more preferably 50 to 100% by weight of softwood kraft pulp and 0 to 50% by weight of hardwood kraft pulp, and even more preferably 70 to 100% by weight of softwood kraft pulp and 0 to 30% by weight of hardwood kraft pulp. By using the above pulp blend, the packaging base material 10 is less likely to tear and is easier to bend at a specified position during packaging, resulting in a packaging body 1 with excellent shape after packaging. Also, unbleached pulp is preferable.

The pulp slurry may contain materials other than pulp fibers as secondary materials. In the packaging body 1, the pulp fiber content is usually preferably 70% by weight or more and 100% by weight or less, more preferably 80% by weight or more and 100% by weight or less, and even more preferably 90% by weight or more and 100% by weight or less. By setting the pulp content above, the packaging base material 10 is less likely to tear and is easier to bend at a specified position during packaging, resulting in a packaging body 1 with excellent shape after packaging.

The cooking and bleaching methods used in pulp production are not particularly limited.

In addition, various commonly used additives, such as wet strength agents, fillers, sizing agents, dry strength agents, retention agents, color pigments, etc., may be added to the paper base material in appropriate amounts as needed.

The wet strength improver can be selected from among those commonly used and known. For example, it is preferable to select from polyamide-polyamine resins, polyacrylamide resins, melamine resins, etc. The amount of the wet strength improver (mass in an absolute dry state) is usually 0.01% by weight to 0.7% by weight, preferably 0.02% by weight to 0.5% by weight, more preferably 0.03% by weight to 0.3% by weight, based on the pulp (mass in an absolute dry state). If the amount of the wet strength improver exceeds 0.7% by weight, it is difficult to obtain an effect commensurate with the amount, resulting in increased costs and reduced disintegration properties, which may make it difficult to reuse the packaging body 1 of the present invention later. If the amount of the wet strength improver is less than 0.01% by weight, it is difficult to obtain sufficient wet strength, and the packaging body 1 may be easily torn when wet with water, resulting in poor functionality.

In the packaging body 1 of the present invention, these raw materials can be made into paper using a normal papermaking process to obtain the paper base material for the packaging base material 10.

The basis weight of the paper base material of the packaging substrate 10 is preferably 20 g/m ² or more and 95 g/m ² or less, more preferably 25 g/m ² or more and 80 g/m ² or less, and even more preferably 30 g/m ² or more and 60 g/m ² or less. If the basis weight is less than 20 g/m ² , the packaging substrate 10 is easily torn. If the basis weight exceeds 95 g/m ² , the packaging substrate 10 is difficult to bend at a predetermined position during packaging, and the shape after packaging is poor. By having the basis weight of the paper base material within the above range, the packaging substrate 10 is difficult to bend and is easy to bend at a predetermined position during packaging, and a package 1 having excellent shape after packaging can be obtained.

The basis weight of the paper base material can be determined, for example, as follows when the packaging base material 10 contains a seal layer as another layer in addition to the paper base material, and the seal layer is a heat seal layer.
First, prepare a 0.1 M acetic acid solution and a 0.1 M sodium acetate solution. Mix about 830 g of the 0.1 M acetic acid solution and about 160 g of the 0.1 M sodium acetate solution to make the pH 4, and use this as an acetate buffer solution. Add cellulase Onozuka P1500 (manufactured by Yakult Co., Ltd.) to this acetate buffer solution so that the amount added is 1 wt%.
50 ml of acetate buffer containing cellulase Onozuka p1500 and 0.5 g of packaging substrate 10 (paper substrate with heat seal layer) are placed in a vial and tightly capped. Next, after shaking for 24 hours at 180 rpm and 40°C, the heat seal layer is sampled from the vial and the mass of the heat seal layer portion is measured. The basis weight of the paper substrate is calculated from the mass (0.5 g) of the packaging substrate 10 and the mass of the sampled heat seal layer according to the following formula.
Basis weight of paper base material =
Basis weight of packaging substrate 10 × [(mass of packaging substrate 10 − mass of heat seal layer) / mass of packaging substrate 10]

The ratio of the basis weight of the paper substrate to the basis weight of the packaging substrate 10 (e.g., the total basis weight of the paper substrate and the seal layer) is preferably 51% or more and 100% or less, more preferably 60% or more and 100% or less, and even more preferably 70% or more and 95% or less. By setting the ratio of the basis weight of the paper substrate to the basis weight of the packaging substrate 10 within the above range, the packaging substrate 10 becomes easier to bend at a specified position, has an excellent shape after packaging, and is less likely to tear.

(2) Seal Layer In the package 1 of the present invention, the packaging substrate 10 may include a seal layer as another layer in addition to the paper substrate, in which case the seal layer is preferably a heat seal layer and/or an adhesive layer. The packaging substrate 10 of the present invention may have a layer structure such as paper substrate/heat seal layer, paper substrate/adhesive layer, paper substrate/heat seal layer/adhesive layer, paper substrate/adhesive layer/heat seal layer, etc.

(2-1) Heat Seal Layer In the case where the package 1 of the present invention includes a heat seal layer, the heat seal layer may be formed on the entire surface of the paper substrate, or may be formed only on a part of the surface, for example, on the part where the paper substrates are laminated or joined together. The position, size, and proportion of the heat seal layer on the surface of the paper substrate can be appropriately set.

The material constituting the heat seal layer is not particularly limited, and any of various materials exhibiting heat sealability can be used, such as polyolefin resins and other thermoplastic resins. Among these, it is preferable to use polyolefin resins. Examples of such materials include low-density polyethylene, linear low-density polyethylene, high-density polyethylene, ethylene-α-olefin copolymers, ethylene-vinyl acetate copolymers, ethylene-acrylic acid copolymers, ethylene-ethyl acrylate copolymers, ethylene-methyl acrylate copolymers, ethylene-methacrylic acid copolymers, ionomers, amorphous polyesters, polypropylene, styrene-acrylic copolymers, propylene-ethylene copolymers (preferably copolymers with an ethylene content of 10 mol% or less), polypropylene-based resins obtained by graft-polymerizing or copolymerizing unsaturated carboxylic acids, unsaturated carboxylic anhydrides, ester monomers, etc. with polypropylene, and medium-density polyethylene. The materials constituting the heat seal layer may be used alone or in combination of two or more.

The heat seal layer can be formed by a commonly used method, for example, a method of forming a film of a thermoplastic resin such as a polyolefin resin or a composition containing a thermoplastic resin on a paper substrate by an extrusion method, a method of attaching a film made of a thermoplastic resin or containing a thermoplastic resin to a paper substrate using a known heat seal processing device (lamination processing device), a method of applying a water-based heat seal agent in which a thermoplastic resin or a thermoplastic resin composition is dissolved or dispersed in water, or a solvent-based heat seal agent in which a thermoplastic resin or a thermoplastic resin composition is dissolved or dispersed in a solvent, to the paper substrate by a known method such as roll coating, gravure roll coating, kiss coating, etc.

The basis weight of the heat seal layer is preferably 50 g/ ^m2 or less, more preferably 5 g/ ^m2 or more and 35 g/ ^m2 or less, and even more preferably 10 g/ ^m2 or more and 25 g/ ^m2 or less. When the basis weight of the heat seal layer is within the above range, the packaging base material 10 is less likely to tear and is easily bent at a predetermined position during packaging, so that a package 1 having an excellent shape after packaging can be obtained. In addition, when the package 1 is sealed by heat sealing, it is easy to seal.

As described above, the package 1 of the present invention may be provided with perforations to make it easier to tear and open the package base material 10. The perforations are required to be easy to open and difficult to tear, but the package 1 packaging a soft toilet roll 11 may be difficult to open or the perforations may tear when opening the package 1 from the perforations depending on the amount of force applied. By setting the basis weight of the heat seal layer within a range of preferably 50 g/m ² or less, more preferably 5 g/m ² or more and 35 g/m ² or less, and even more preferably 10 g/m ² or more and 20 g/m ² or less, it is possible to achieve both ease of opening and difficulty of tearing when opening the package 1 from the perforations.

The basis weight of the heat seal layer can be determined, for example, as follows.
First, prepare a 0.1 M acetic acid solution and a 0.1 M sodium acetate solution. Mix about 830 g of the 0.1 M acetic acid solution and about 160 g of the 0.1 M sodium acetate solution to make the pH 4, and use this as an acetate buffer solution. Add cellulase Onozuka P1500 (manufactured by Yakult Pharmaceutical Co., Ltd.) to this acetate buffer solution so that the amount added is 1 wt %.
50 ml of acetate buffer containing cellulase Onozuka p1500 and 0.5 g of packaging substrate 10 (paper substrate with heat seal layer) are placed in a vial and tightly capped. Next, after shaking for 24 hours at 180 rpm and 40°C, the heat seal layer is sampled from the vial and the mass of the heat seal layer portion is measured. The basis weight of the heat seal layer is calculated from the mass (0.5 g) of the packaging substrate 10 (paper substrate with heat seal layer) and the mass of the sampled heat seal layer according to the following formula.
Basis weight of heat seal layer =
Basis weight of packaging substrate 10 × (mass of heat seal layer / mass of packaging substrate 10)

(2-2) Adhesive Layer In the package 1 of the present invention, when the packaging substrate 10 includes an adhesive layer as another layer in addition to the paper substrate, the adhesive layer may be formed on the entire surface of the paper substrate or the heat seal layer formed on the paper substrate, or may be formed only on a part of the surface, for example, a portion where the paper substrates are laminated and joined together. The position, size, and proportion of the adhesive layer on the surface of the paper substrate can be appropriately set.

The adhesive constituting the adhesive layer is not particularly limited, and any known adhesive can be used, such as an ethylene-based adhesive, a two-component curing urethane-based adhesive, a polyester urethane-based adhesive, a polyether urethane-based adhesive, an acrylic-based adhesive, a styrene-acrylic-based adhesive, a polyester-based adhesive, a polyamide-based adhesive, a polyvinyl acetate-based adhesive, an epoxy-based adhesive, or a rubber-based adhesive. Of these, a styrene-acrylic-based adhesive is preferred.

The adhesive layer can be formed by applying the adhesive to the paper substrate or to a heat seal layer formed on the paper substrate by a known method such as roll coating, gravure roll coating, kiss coating, etc.

The basis weight of the adhesive layer (dry coating amount of adhesive) is usually preferably 2 g/ ^m2 or more and 30 g/ ^m2 or less, more preferably 3 g/ ^m2 or more and 25 g/ ^m2 or less, and even more preferably 5 g/ ^m2 or more and 20 g/ ^m2 or less.
The basis weight of the adhesive layer is calculated from the basis weight of the packaging substrate 10 and the basis weight of the paper substrate measured in accordance with JIS P 8124 before the adhesive layer is provided, using the following formula.
Basis weight of adhesive layer = Basis weight of packaging substrate 10 - Basis weight of paper substrate

As mentioned above, in the packaging substrate 10 of the present invention, the seal layer is preferably a heat seal layer and/or an adhesive layer, but a heat seal layer, particularly a heat seal layer containing a polyolefin resin, usually has better adhesion than an adhesive layer, and providing a heat seal layer, preferably a heat seal layer containing a polyolefin resin, may make it easier to package the toilet roll 11.

(3) Other layers The packaging substrate 10 of the present invention may have other layers in addition to the paper substrate. Examples of layers other than the above-mentioned seal layer and adhesive layer include a water vapor barrier layer, an oxygen barrier layer, a printing layer, a printability improving layer, an overprint layer, a light-shielding layer, etc. These other layers can be provided, for example, on the front side or back side of the paper substrate, and may be one layer or two or more layers.

(4) Physical Properties of the Entire Packaging Substrate As described later, there are various packaging formats for the packaging body 1 according to the present invention, including a case where the toilet roll 11 is wrapped from the production line direction (conveyance direction; MD direction) and a case where the toilet roll 11 is wrapped from the width direction (CD direction) perpendicular to the production line direction. When the toilet roll 11 is wrapped from the MD direction, the tensile strength of the packaging substrate 10 in the MD direction is preferably 2.0 kN/m or more and 8.3 kN/m or less, more preferably 2.5 kN/m or more and 7.0 kN/m or less, and even more preferably 3.0 kN/m or more and 6.0 kN/m or less. When wrapping the toilet roll 11 from the CD direction, the tensile strength of the packaging substrate 10 in the CD direction is preferably 0.7 kN/m or more and 3.5 kN/m or less, more preferably 0.9 kN/m or more and 3.0 kN/m or less, and even more preferably 1.1 kN/m or more and 2.5 kN/m or less. By setting the tensile strength of the packaging substrate 10 in the MD direction and the CD direction within the above range, the packaging substrate 10 is less likely to break and is easily bent at a predetermined position during packaging, and a package 1 having excellent shape after packaging can be obtained. The tensile strength of the packaging substrate 10 can be measured in accordance with JIS P 8113.

The burst strength of the packaging substrate 10 is 65 kPa or more and 295 kPa or less, preferably 75 kPa or more and 260 kPa or less, and more preferably 100 kPa or more and 210 kPa or less. If the burst strength is less than 65 kPa, the loosened portion 10s of the packaging substrate 10 is easily torn when the package is held, and if the burst strength exceeds 295 kPa, the packaging substrate 10 is difficult to bend at a predetermined position during packaging, resulting in a poor shape after packaging. By setting the burst strength of the packaging substrate 10 within the above range, the packaging substrate 10 is difficult to bend and easily bent at a predetermined position during packaging, resulting in a package 1 with excellent shape after packaging. The burst strength of the packaging substrate 10 can be measured in accordance with JIS P 8112.

When wrapping the toilet roll 11 from the MD direction, the bending stiffness of the packaging substrate 10 in the MD direction is preferably 18 μN·m or more and 300 μN·m or less, more preferably 30 μN·m or more and 200 μN·m or less, and even more preferably 45 μN·m or more and 150 μN·m or less. When wrapping the toilet roll 11 from the CD direction, the bending stiffness of the packaging substrate 10 in the CD direction is preferably 8 μN·m or more and 130 μN·m or less, more preferably 13 μN·m or more and 100 μN·m or less, and even more preferably 20 μN·m or more and 60 μN·m or less. By having the bending stiffness of the packaging substrate 10 in the MD direction or CD direction within the above range, the packaging substrate 10 is less likely to break and is easily bent at a predetermined position during packaging, and a package 1 with excellent shape after packaging can be obtained. In addition, the required flexibility and softness of the packaging substrate 10 is easily achieved. The bending stiffness of the packaging substrate 10 can be measured in accordance with ISO 2493. Note that bending stiffness is strongest when a load is applied in the longitudinal direction of the fibers, so when the fiber orientation ratio is close to 1.0, bending stiffness in the MD direction tends to be small and bending stiffness in the CD direction tends to be large.

The thickness of the packaging substrate 10 of the present invention is preferably 35 μm or more and 135 μm or less, more preferably 40 μm or more and 120 μm or less, and even more preferably 60 μm or more and 100 μm or less. By setting the thickness of the packaging substrate 10 within the above range, the packaging substrate is less likely to tear and is easier to bend at a predetermined position during packaging, resulting in a package 1 with excellent shape after packaging. The thickness of the packaging substrate 10 can be measured in accordance with JIS P 8118:1998. The pressure condition of the pressurized surface was 100 kPa.

The density of the packaging substrate 10 is preferably 0.55 g/cm ³ or more and 0.95 g/cm ³ or less, more preferably 0.60 g/cm ³ or more and 0.90 g/cm ³ or less, and even more preferably 0.65 g/cm ³ or more and 0.85 g/cm ³ or less. When the density of the packaging substrate 10 is within the above range, the packaging substrate 10 is difficult to break and is easily bent at a predetermined position during packaging, and a package 1 having excellent shape after packaging can be obtained. In addition, the required strength, flexibility and softness of the packaging substrate 10 are easily achieved. The density of the packaging substrate 10 can be measured and calculated in accordance with JIS P 8118:1998.

3. Toilet roll Fig. 3 is a perspective view showing an example of the arrangement of toilet rolls 11 packaged in the package 1 of the present invention. The package 1 of the present invention packages two, four or six toilet rolls 11, and the toilet rolls 11 are arranged in two or three rows perpendicular to the axial direction, with both end faces aligned in each row. The arrangement is preferably any of the arrangements shown in Fig. 3(b) to (e), more preferably the arrangement shown in Fig. 3(c) or (d), and even more preferably the arrangement shown in Fig. 3(c). As shown in Fig. 2, the package 1 of the present invention specifies the slack in the circumferential direction P described above, so an arrangement such as that shown in Fig. 3(a) is not included in the embodiment.

The number of plies of the toilet roll 11 is not particularly limited, but is preferably 1 ply or 2 plies, and more preferably 2 plies.
In the case of a two-ply toilet roll 11, the roll length is preferably 25 m or more and 103 m or less, more preferably 40 m or more and 95 m or less, and even more preferably 55 m or more and 85 m or less. In the case of a one-ply toilet roll 11, the roll length is preferably 50 m or more and 203 m or less, more preferably 80 m or more and 190 m or less, and even more preferably 110 m or more and 170 m or less.
Furthermore, the roll diameter of the toilet roll 11 is preferably 105 mm or more and 140 mm or less, more preferably 110 mm or more and 133 mm or less, and even more preferably 115 mm or more and 125 mm or less.
By setting the density within the above range, it is easy to adjust the roll density to a predetermined value. Furthermore, when the toilet roll 11 is packaged with the packaging substrate 10, the packaging substrate 10 is less likely to break and is more likely to bend at a predetermined position during packaging, so that a package 1 having an excellent shape after packaging can be obtained.

The outer diameter of the core (paper tube) of the toilet roll 11 is preferably 25 m or more and 55 m or less, more preferably 30 m or more and 50 m or less, and even more preferably 35 m or more and 45 m or less.
In addition, the basis weight per ply of the toilet roll 11 is preferably 12 g/m2 or more and 19 g/ ^{m2 or} less, more preferably 13 g/ ^m2 or more and 18 g/ ^m2 or less, and even more preferably 14 g/ ^m2 or more and 17 g/ ^m2 or less, in the case of two plies. In the case of one ply, it is preferably 13 g/ ^m2 or more and 22 g/ ^m2 or less, more preferably 14 g/ ^m2 or more and 21 g/ ^m2 or less, and even more preferably 15 g/ ^m2 or more and 20 g/ ^m2 or less.
Furthermore, the weight per 114 mm of the roll width of the toilet roll 11 excluding the core is preferably 100 g or more and 370 g or less, more preferably 130 g or more and 340 g or less, and even more preferably 200 g or more and 300 g or less.
By setting the density within the above range, it is easy to adjust the roll density to a predetermined value. Furthermore, when the toilet roll 11 is packaged with the packaging substrate 10, the packaging substrate 10 is less likely to tear and is more likely to bend at a predetermined position during packaging, so that a package 1 having an excellent shape after packaging can be obtained.

The roll density of the toilet roll 11 is 0.1 g/cm ³ or more and 0.33 g/cm ³ or less, preferably 0.12 g/cm ³ or more and 0.31 g/cm ³ or less, and more preferably 0.18 g/cm ³ or more and 0.27 g/cm ³ or less. If the roll density is less than 0.1 g/cm ³ , the toilet roll 11 is soft and the shape is not stable, so the packaging substrate 10 bends at an unintended place during packaging, resulting in poor shape after packaging. If the roll density exceeds 0.33 g/cm ³ , the part of the packaging substrate 10 that is not in contact with the toilet roll 11 is likely to be in a taut state, and the packaging substrate 10 is likely to break when the package 1 is held. By setting the roll density of the toilet roll 11 within the above range, the packaging substrate 10 is unlikely to break, and is likely to bend at a predetermined position during packaging, resulting in a package 1 with excellent shape after packaging.
The roll density is calculated by multiplying the base area of one toilet roll 11 excluding the core by the roll width (height) (i.e., the volume of one toilet roll 11 excluding the core), and dividing the mass of one toilet roll 11 excluding the core by this volume.
For example, if the roll weight (excluding the core) per 114 mm of roll width is 201 g, the winding diameter is 130 mm, and the outer diameter of the core is 39 mm, the roll density = 201 g ÷ [{3.14 × (130 mm ÷ 2 ÷ 10) ² - 3.14 × (39 mm ÷ 2 ÷ 10) ² } × (114 mm ÷ 10)] = 0.15 g/cm ³ .

Furthermore, the ratio (B/A) of the slackness (B) in the circumferential direction P to the roll density (A) is 13 to 200, preferably 25 to 155, and more preferably 40 to 100. If the ratio (B/A) is less than 13, the portion of the packaging substrate 10 that is not in contact with the toilet roll 11 is likely to be in a taut state, and the packaging substrate 10 is likely to tear when the package 1 is held. If the ratio (B/A) exceeds 200, the circumference of the packaging substrate 10 relative to the toilet roll 11 becomes large (long), and the packaging substrate 10 bends in unintended places during packaging, resulting in a poor shape after packaging.

The paper thickness of 10 sheets of toilet paper (10 sheets in the case of 1 ply, 10 sheets in the case of 2 ply for 5 sets) used in the toilet roll 11 is preferably 0.5 mm/10 sheets or more and 1.2 mm/10 sheets or less, more preferably 0.6 mm/10 sheets or more and 1.1 mm/10 sheets or less, and even more preferably 0.7 mm/10 sheets or more and 1.0 mm/10 sheets or less.
The paper thickness is measured using a thickness gauge (a dial thickness gauge "PEACOCK" manufactured by Ozaki Manufacturing Co., Ltd.). The measurement conditions are a measurement load of 3.7 kPa, a gauge head diameter of 30 mm, a sample is placed between the gauge head and the measurement table, and the gauge is read when the gauge head is lowered at a speed of 1 mm or less per second. The measurement is repeated 10 times and the measurement results are averaged.

The dry longitudinal tensile strength (DMDT) per two plies is preferably 2.5 N/25 mm to 6.5 N/25 mm, more preferably 2.8 N/25 mm to 6.0 N/25 mm, and even more preferably 3.1 N/25 mm to 5.5 N/25 mm. The dry transverse tensile strength (DCDT) per two plies is preferably 0.6 N/25 mm to 3.0 N/25 mm, more preferably 0.8 N/25 mm to 2.5 N/25 mm, and even more preferably 1.0 N/25 mm to 2.0 N/25 mm.
The tensile strength in the machine direction and the cross direction when dry can be measured and calculated in accordance with JIS P 8113.
The roll density, paper thickness and tensile strength are measured after maintaining the paper in an equilibrium state under temperature and humidity conditions specified in JIS P 8111 (23±1° C., 50±2% RH).

4. Packaging Format An example of the packaging format of the package 1 according to the present invention is caramel packaging.

Caramel packaging is a packaging format in which a packaging base material that extends in one direction of the packaged item is wrapped around the packaged item in a direction parallel to or intersecting this direction, or the packaged item is placed into one end of the axial direction of a packaging base material that has been previously formed into a cylindrical shape. Then, of the packaging base material that protrudes from both ends of the packaged item, two opposing flap-shaped sides are folded together, and then another two opposing flap-shaped sides are folded together in the same manner, and these folded parts are sealed with an adhesive such as glue, or if the packaging base material has a heat seal layer or adhesive layer, sealed with a heat seal. This caramel packaging can be performed using a known device. In FIG. 1, flaps are formed on both ends parallel to the axis of the toilet roll 11, but flaps may also be formed on both ends perpendicular to the axial direction L of the toilet roll 11.

In one embodiment, for example, when using a packaging substrate 10 having a bending stiffness in the MD direction of 18 μN·m or more and 300 μN·m or less, the packaging body of the present invention is particularly suitable for use in the case where, for example, the packaging substrate 10 is transported in the form of a continuous sheet, the toilet roll 11 is placed, and then the toilet roll 11 is wrapped and packaged from the transport direction (manufacturing line direction; MD direction), and cut to a predetermined dimension from the width direction (CD direction) perpendicular to the transport direction, that is, when the wrapping direction is the MD direction of the packaging substrate 10. When the wrapping direction is the MD direction, the packaging substrate 10 becomes easier to bend in the vertical direction, and packaging becomes easier when folding and adhering the flaps at the top and bottom parts. In this case, it is preferable to select caramel packaging as the packaging format for the packaging body 1 of the present invention. Note that the toilet roll 11 may be placed after the packaging substrate 10 is cut to a predetermined size, or the toilet roll 11 may be placed after the packaging substrate 10 is cut to a predetermined size.

In another embodiment, for example, when using a packaging substrate 10 having a bending stiffness in the CD direction of 8 μN·m or more and 130 μN·m or less, the packaging body 1 of the present invention is particularly suitable for use when, for example, the packaging substrate 10 is transported in the form of a continuous sheet, the toilet roll 11 is placed, and then the toilet roll 11 is wrapped and packaged from the width direction (CD direction) perpendicular to the transport direction (manufacturing line direction; MD direction), that is, when the wrapping direction is the CD direction of the packaging substrate 10. If the wrapping direction is the CD direction of the packaging substrate, the packaging substrate 10 becomes easier to bend in the wrapping direction, making it easier to package. In this case, the toilet roll 11 may be placed after the packaging substrate 10 is cut to a predetermined size, or the toilet roll 11 may be placed after the packaging substrate 10 is cut to a predetermined size.

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 and examples. It will be clear to those skilled in the art that various modifications and improvements can be made to the above embodiments. Furthermore, it is clear from the claims that forms incorporating such modifications or improvements can also be included in the technical scope of the present invention.

The present invention will be described in detail below with reference to examples. Note that the present invention is not limited to the examples shown below.

In the examples and comparative examples, the physical properties of the packaging substrates prepared were measured using the following methods.

(Basis weight of packaging substrate)
The basis weight of the packaging substrate was measured in accordance with JIS P 8124.

(Basis weight of paper base material and basis weight of heat seal layer)
First, 0.1M acetic acid aqueous solution and 0.1M sodium acetate aqueous solution were prepared. Approximately 830g of 0.1M acetic acid aqueous solution and approximately 160g of 0.1M sodium acetate aqueous solution were mixed to a pH of 4, and this was used as an acetate buffer solution. Cellulase Onozuka p1500 (manufactured by Yakult Pharmaceutical Co., Ltd.) was added to this acetate buffer solution so that the amount added was 1 wt%.
50 ml of acetate buffer containing cellulase Onozuka p1500 and 0.5 g of packaging substrate (paper substrate with heat seal layer) were placed in a vial and tightly capped. Next, after shaking for 24 hours at 180 rpm and 40°C, the heat seal layer was sampled from the vial and the mass of the heat seal layer was measured. The basis weight of the paper substrate and the basis weight of the heat seal layer were calculated from the mass (0.5 g) of the packaging substrate (paper substrate with heat seal layer) and the mass of the sampled heat seal layer according to the following formula.
Basis weight of paper base material =
Basis weight of packaging substrate × [(mass of packaging substrate − mass of heat seal layer) / mass of packaging substrate]
Basis weight of heat seal layer =
Basis weight of packaging substrate × (mass of heat seal layer / mass of packaging substrate)

(Basis weight of adhesive layer (amount of adhesive applied))
The basis weight of the adhesive layer was calculated according to the following formula from the basis weight of the packaging base material determined as above and the basis weight of the paper base material measured in accordance with JIS P 8124 before providing the adhesive layer.
Basis weight of adhesive layer = grammage of packaging substrate - grammage of paper substrate

(Thickness of packaging substrate)
The thickness of the packaging substrate was measured in accordance with JIS P 8118: 1998 using an automatic elevating paper thickness gauge standard model TM-600 (manufactured by Kumagai Riki Kogyo Co., Ltd.) The pressure condition of the pressing surface was 100 kPa.

(Density of packaging substrate)
The density of the packaging base material was measured and calculated in accordance with JIS P 8118:1998.

(Tensile strength in MD and CD of packaging substrate)
The tensile strength in the MD and CD directions of the packaging substrate was measured in accordance with JIS P 8113.

(Burst strength of packaging substrate)
The burst strength of the packaging substrate was measured in accordance with JIS P 8112. Note that the measurement was performed using a Mullen burst strength tester manufactured by Kumagai Riki Kogyo Co., Ltd. under low pressure measurement conditions.

(Measurement of bending stiffness in MD and CD directions of packaging substrate)
The bending stiffness of the packaging substrate in the MD and CD directions was measured using an L&W bending tester (manufactured by Lorentzen & Wettre) in accordance with the method described in ISO 2493. The packaging substrate was a test piece with a width of 38 mm and a length of 100 mm, and the measured value when the bending angle was 15 degrees and the bending length (span of the sample stage) was 10 mm was taken as the bending resistance (load), and the bending stiffness (μN·m) was calculated using the following formula.
Bending stiffness (μN·m) = 60 × bending resistance (mN) × bending length 10 (mm) ² ÷ (π × bending angle 15 (°) × sample width 38 (mm))
If it is not possible to obtain a test specimen of 100 mm in length, the length of the test specimen may be shortened. Furthermore, the test specimen should not include a perforation, but if it is necessary to include a perforation to ensure the size of the test specimen, the test specimen may include a perforation.

Example 1
(Packaging substrate)
A paper base material was prepared using 100% by weight of softwood unbleached kraft pulp (NUKP) as the pulp raw material. A polyethylene layer was then formed as a heat seal layer on the paper base material by extrusion to prepare a packaging base material. The results of measuring the basis weights of the prepared packaging base material, paper base material, and heat seal layer, the ratio of the paper base material, the thickness of the packaging base material, density, tensile strength in the MD and CD directions, bending stiffness in the MD and CD directions, and burst strength are shown in Tables 1 and 2.

(Toilet roll)
In addition, four toilet rolls having the winding length, winding diameter, number of plies, core outer diameter, basis weight per ply, weight per 114 mm of roll width, and roll density shown in Tables 1 and 2 were prepared.

(Toilet roll packaging (caramel packaging))
Using the prepared packaging base material, a package was prepared with a dimension of 430 cm in the MD direction of the packaging base material and 655 cm in the CD direction of the packaging base material. Four toilet rolls (2 vertically and 2 horizontally) were placed in this package and sealed with caramel packaging to obtain a toilet roll package. The toilet roll was wrapped in the package from the CD direction.
Then, in the toilet roll packaging, the slack in the circumferential direction P of the packaging base material was measured, and the ratio (B/A) of the slack in the circumferential direction P (B) to the roll density (A) was calculated.

(Resistant to tearing of packaging substrate)
The produced toilet roll packaging was evaluated by 30 monitors for tear resistance of the packaging base material when the packaging was held from both sides with one hand. The evaluation criteria were as follows.
5: 0-1 person felt that the packaging base material was easily torn 4: 2-3 people felt that the packaging base material was easily torn 3: 4-6 people felt that the packaging base material was easily torn 2: 7-20 people felt that the packaging base material was easily torn 1: 21-30 people felt that the packaging base material was easily torn

(Good appearance after packaging (beauty))
The toilet roll packaging thus produced was visually inspected and evaluated by 30 panelists for appearance (beauty). The evaluation criteria were as follows:
5: 0-1 person who felt that the packaging base material was loose or not bent in the specified place, resulting in poor cosmetic appearance 4: 2-3 people who felt that the packaging base material was loose or not bent in the specified place, resulting in poor cosmetic appearance 3: 4-6 people who felt that the packaging base material was loose or not bent in the specified place, resulting in poor cosmetic appearance 2: 7-20 people who felt that the packaging base material was loose or not bent in the specified place, resulting in poor cosmetic appearance 1: 21-30 people The resistance to tearing of the packaging base material and the quality of the shape after packaging were evaluated from two perspectives: the roll density of the toilet roll and the slackness of the packaging base material in the circumferential direction, and the basis weight of the packaging base material.

(Example 2) to (Example 24), (Comparative Example 1) to (Comparative Example 8)
In Examples 2 to 24 and Comparative Examples 1 to 8, packaging substrates having the physical properties shown in Tables 1 and 2 were prepared in the same manner as in Example 1, and toilet roll packages (caramel packages) were prepared using these in the same manner as in Example 1, and the tear resistance and shape after packaging of the packaging substrates were evaluated. However, in Example 23, a paper substrate having neither an adhesive layer nor a heat seal layer was used. In Example 24, instead of providing a polyethylene layer as a heat seal layer on the paper substrate, a styrene-acrylic adhesive layer (adhesive coating amount 17.5 g/m ² ) was provided, and the basis weight of the adhesive layer was measured. Furthermore, in each Example and Comparative Example, the size of the packaging substrate was appropriately adjusted.

As is clear from the results shown in Tables 1 and 2, the packaging substrate of each of the packages of Examples 1 to 24 was not easily torn and had an excellent shape after packaging. In contrast, the packaging substrate of each of the packages of Comparative Examples 1 to 8 was easily torn or had a poor shape after packaging.
Therefore, the package of the present invention can provide a toilet roll package that maintains a good shape after packaging and is less likely to tear, even when the toilet roll is packaged in a packaging base material mainly made of paper.

1 Packaging body 10, 20, 30 Packaging base material 10s, 20s, 30s Loose portion 11, 21, 31 Toilet roll L Axial direction of toilet roll P Circumferential direction of packaging base material S First ruler SL Reference line R Second ruler Rt Thickness direction of second ruler D Sinking amount of packaging base material

Claims (4)

A package in which 2, 4 or 6 toilet rolls are packaged in a packaging substrate including at least a paper substrate,
The packaging substrate has a basis weight of 30 g/ ^m2 or more and 105 g/ ^m2 or less, and a burst strength of 65 kPa or more and 295 kPa or less,
The packaging substrate includes a paper substrate and an adhesive layer which is a seal layer;
The ratio (%) of the basis weight of the paper base material to the basis weight of the packaging base material is 70% or more and 95% or less ;
The content of pulp fibers in the paper base material is 80% by weight or more and 100% by weight or less,
The toilet rolls are arranged in two or three rows in a direction perpendicular to their axial direction, and both end faces of each row are aligned,
The roll density of the toilet roll is 0.1 g/ ^cm3 or more and 0.33 g/ ^cm3 or less,
The slack in the circumferential direction of the packaging substrate when the toilet roll is packaged is 4 mm or more and 38 mm or less,
A toilet roll packaging body, characterized in that a ratio (B/A) of the slackness (B) in the circumferential direction to the roll density (A) is 13 or more and 200 or less. The toilet roll packaging of claim 1, characterized in that the bending stiffness of the packaging base material in the CD direction is 8 μN·m or more and 130 μN·m or less. The toilet roll packaging body according to claim 1 or 2, characterized in that the bending stiffness of the packaging base material in the MD direction is 18 μN·m or more and 300 μN·m or less. 4. The toilet roll packaging according to any one of claims 1 to 3, characterized in that the packaging is a caramel packaging.