JP7729533B2 - Packaging bag and sheet packaging body - Google Patents

Description

The present invention relates to a packaging bag and a sheet packaging body.

Sheet packages containing sheets such as paper towels and tissue paper are distributed and used in a state in which multiple sheets are contained in a packaging bag made of resin film (see, for example, Patent Documents 1 and 2). In recent years, from the viewpoint of reducing environmental impacts such as global warming due to _CO2 emissions and marine pollution caused by microplastics, attention has been focused on changing the material of the packaging bag in sheet packages from resin to paper.

JP 2008-183034 A Japanese Patent Application Laid-Open No. 2018-177364

However, paper packaging bags are less flexible than plastic packaging bags, so when perforations are provided for opening, the perforations are difficult to tear and the bags are difficult to open.

The objective of this invention is to provide a paper packaging bag that is easy to open.

A first aspect of the present invention provides a packaging bag for containing a sheet, the packaging bag being made of a substrate containing a paper component, the substrate including a base layer containing the paper component and an outer layer laminated on either side of the base layer and positioned on the outside of the packaging bag, the outer layer including a gripping agent.

In this specification, the paper component refers to agglutinated plant fibers. The outside of the packaging bag refers to the side of the substrate that does not come into contact with the sheet contained in the packaging bag (i.e., the side opposite the side where the sheet is contained in the packaging bag or the side where the outer layer of the substrate is formed). A gripping agent is an agent that increases the coefficient of friction.

In a first aspect, the substrate of the packaging bag includes a base layer containing a paper component and an outer layer laminated on either side of the base layer and positioned on the outside of the packaging bag. The outer layer contains a gripping agent, which increases the frictional force generated between the outer layer of the substrate and the fingers of a person touching the outer layer of the substrate (hereinafter referred to as fingers). This makes it less likely for fingers touching the substrate to slip relative to the substrate, so if a paper packaging bag has perforations, the perforations are more likely to tear, making it easier to open even a paper packaging bag.

A second aspect of the present invention provides a packaging bag having a first static friction coefficient between the sheet and the inner surface of the substrate placed inside the packaging bag, and a second static friction coefficient between the artificial skin and the outer surface of the substrate on which the outer layer is formed, the second static friction coefficient being greater than the first static friction coefficient.

In this specification, the static friction coefficient refers to the ratio of the frictional force occurring at the contact surface between two objects when there is no relative motion to the force acting perpendicular to the contact surface. The inside of a packaging bag refers to the side of the substrate that contacts the sheet contained in the packaging bag (i.e., the side on which the sheet is contained in the packaging bag or the side on which the inner layer of the substrate is formed).

The inner surface of the substrate placed inside the packaging bag refers to the surface of the substrate that comes into contact with the sheet contained in the packaging bag (i.e., the surface opposite to the side on which the inner layer of the substrate is formed or the side on which the outer layer of the substrate is formed).

In this specification, the outer surface of the material on which the outer layer is formed refers to the surface that does not come into contact with the sheet contained in the packaging bag (i.e., the surface on which the outer layer of the substrate is formed or the surface opposite to the surface on which the inner layer of the substrate is formed). Artificial skin refers to a urethane molded product that mimics human skin.

In the second aspect, by making the second static friction coefficient between the artificial skin and the outer surface of the substrate on which the outer layer is formed greater than the first static friction coefficient between the sheet and the inner surface of the substrate placed inside the packaging bag, the friction force between the outer surface of the substrate and the artificial skin becomes relatively greater than the friction force between the inner surface of the substrate and the sheet. This makes it easier to tear the perforations on the paper packaging bag, making it easier to open the packaging bag.

A third aspect of the present invention provides a packaging bag in which the first static friction coefficient is 0.55 or less.

In the third aspect, the first static friction coefficient between the sheet and the inner surface of the substrate placed inside the packaging bag is 0.55 or less, making the inner surface of the substrate containing a paper component slippery against the sheet. This makes it even easier to tear the perforations on the paper packaging bag, making it even easier to open the packaging bag.

A fourth aspect of the present invention provides a packaging bag in which the ratio of the first static friction coefficient to the second static friction coefficient is 0.65 or less. In this specification, the ratio of the first static friction coefficient to the second static friction coefficient refers to the ratio of the first static friction coefficient to the second static friction coefficient.

In the fourth aspect, by setting the ratio of the first static friction coefficient to the second static friction coefficient to 0.65 or less, the difference between the friction coefficient of the inner surface of the substrate relative to the sheet and the friction coefficient of the outer surface of the substrate relative to the artificial skin becomes larger. This makes it easier to tear the perforations in the paper packaging bag, making it even easier to open the packaging bag.

A fifth aspect of the present invention provides a packaging bag in which the second static friction coefficient is 1.1 or less. In paper packaging bags, the difference between the first static friction coefficient and the second friction coefficient should be as large as possible to improve ease of opening. On the other hand, if the second friction coefficient is too large relative to the first static friction coefficient, there is a risk that the frictional force from outside the packaging bag will cause the perforations in the packaging bag to tear before the packaging bag is opened (for example, during distribution of a sheet package using the packaging bag).

Therefore, in the fifth aspect, the second static friction coefficient is adjusted to 1.1 or less so that the outer surface of the substrate does not become too slippery, thereby preventing unexpected tearing of the packaging bag without reducing the ease of opening the packaging bag.

A sixth aspect of the present invention provides a packaging bag, wherein the first static friction coefficient is the static friction coefficient between the CD direction of the substrate and the MD direction of the sheet, and the second static friction coefficient is the static friction coefficient between the CD direction of the substrate and the artificial skin. In this specification, the MD direction is the direction corresponding to the traveling direction of the substrate relative to a papermaking machine that manufactures the substrate constituting the paper packaging bag, and the CD direction is the direction perpendicular to the traveling direction.

In the sixth aspect, by setting the static friction coefficient between the CD direction of the substrate and the MD direction of the sheet to a first static friction coefficient, the CD direction of the substrate becomes more easily slippery relative to the MD direction of the sheet. Furthermore, by setting the static friction coefficient between the CD direction of the substrate and the artificial skin to a second static friction coefficient, the artificial skin becomes less likely to slip relative to the CD direction of the substrate.

As a result, if the sheet is placed in a packaging bag so that the MD direction of the sheet is aligned with the CD direction of the substrate and the perforations are formed in the MD direction of the substrate, the perforations will tear when the thumbs of both hands are pressed against the surface of the packaging bag where the perforations are formed and the thumbs are moved apart in the CD direction of the substrate. At this time, the perforations tear easily with little force, making it even easier to open the packaging bag.

A seventh aspect of the present invention provides a packaging bag in which a tearing score line is formed on the top surface of the packaging bag along the MD direction of the base material. In this specification, the tearing score line refers to a score line (e.g., a perforation) in which cuts and ties (uncut portions between two cuts) are arranged alternately, and when a tie is broken, the adjacent cuts on both sides become continuous cuts.

In the seventh aspect, by forming a tearing score line along the MD direction of the substrate on the top surface of the packaging bag, the tearing score line can be torn by simply pressing the top surface of the packaging bag with the thumbs of both hands and moving the thumbs apart in the CD direction of the substrate, making it easy to open the packaging bag. Furthermore, the torn tearing score line can form the sheet removal opening formed on the top surface of the packaging bag.

An eighth aspect of the present invention provides a sheet packaging body comprising a packaging bag according to any one of the first to seventh aspects and a sheet contained in the packaging bag. In the eighth aspect, by constructing a sheet packaging body in which a sheet is contained in the packaging bag described above, the same effects as the packaging bag described above can be achieved. In other words, according to the eighth aspect, even if the packaging bag constituting the sheet packaging body is made of paper, it is possible to provide a sheet packaging body that makes it easy to open the paper packaging bag.

One aspect of the present invention provides a paper packaging bag that is easy to open.

FIG. 10 is a diagram showing a sheet package in which sheets are housed in a packaging bag. FIG. 10 is a diagram showing a sheet contained in a packaging bag. 2 is a view of the sheet packaging body of FIG. 1 as seen from the top side. FIG. 2 is a view of the sheet packaging body of FIG. 1 as seen from the bottom side. FIG. 2 is a front view of the sheet wrapping body of FIG. 1; FIG. 2 is a view of the sheet wrapping body of FIG. 1 as seen from the rear side. FIG. 2 is a view of the sheet wrapping body of FIG. 1 as seen from the left side. FIG. 2 is a view of the sheet wrapping body of FIG. 1 as seen from the right side. FIG. 1 is a diagram showing an example of a cross section of a base material of a packaging bag (first embodiment). FIG. FIG. 10 is a diagram showing the state in which the packaging bag of the sheet packaging body is opened. 10A and 10B are diagrams showing a state in which the sheet wrapping body is used.

<Package>
An embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, common parts are given the same reference numerals and their description may be omitted. In addition, the scale of each part in each drawing may differ from the actual scale. In each drawing, a three-dimensional Cartesian coordinate system with three axial directions (X direction, Y direction, and Z direction) is used, with the longitudinal direction of the packaging bag being the X direction, the width direction being the Y direction, and the height direction (vertical direction or thickness direction) being the Z direction.

Figure 1 is a diagram showing a sheet package in which a sheet is contained in a packaging bag of the embodiment. Figure 2 is a diagram showing a sheet contained in the packaging bag of the embodiment. Figures 3, 4, 5, 6, 7, and 8 are views of the sheet package of Figure 1 from the top, bottom, front, back, left side, and right side, respectively.

As shown in FIG. 1, the sheet packaging body 100 includes a packaging bag 10 and a sheet stack 20 (multiple sheets S). The sheet packaging body 100 is an example of a sheet packaging body according to this embodiment. The packaging bag 10 is an example of a packaging bag that constitutes the sheet packaging body according to this embodiment. The sheet stack 20 is an example of a sheet that is contained in the packaging bag according to this embodiment.

As shown in Figure 2, the packaging bag 10 contains multiple stacked sheets (or multiple sets) of sheets S (sheet stack 20). The sheet stack 20 is contained in the packaging bag 10 so that the stacking direction (SD direction) of the sheets S is the height direction (Z direction). The sheet stack 20 is designed so that the sheets S can be pulled out one set at a time through an outlet (opening OP) formed in the packaging bag 10, which will be described later (see Figure 11).

The form of the sheet stack 20 is not particularly limited, and may be, for example, a stack of sheets S in a folded state, a stack of sheets S in a staggered state (a so-called pop-up sheet stack), or a simple stack of multiple sheets S.

The dimensions of the sheet S (sheet stack 20) can be approximately 150-250 mm in length L2 in the longitudinal direction (X direction) of the packaging bag 10, approximately 70-150 mm in width W2 in the width direction (Y direction) perpendicular to the longitudinal direction (X direction) of the packaging bag 10, and approximately 20-100 mm in height H2 in the height direction (Z direction) (see Figures 2 and 3). Such tissue paper stacks can be manufactured, for example, using a rotary or multi-stand interfolder.

The form of the sheet S is not particularly limited, and it can be applied to sanitary thin papers such as paper towels, kitchen paper, tissue paper, and toilet paper. These sanitary thin papers also include sanitary thin papers containing moisturizing ingredients (e.g., lotion tissues, etc.).

The use of the sheet S is not particularly limited, and it can be used for industrial, household, or portable purposes. Among these, household and portable paper towels are preferred as the sheet used in this embodiment.

The number of plies in the sheet S is not particularly limited, but can be one or more, and is preferably one or two plies (two layers stacked). The shape of the sheet S is also not particularly limited, but it is preferable that the outline shape of a two-ply sheet when folded is quadrangular (rectangular, square, etc.).

The material of the sheet S is not particularly limited, but can be, for example, paper, nonwoven fabric, cloth, or other sheets, with paper (paper sheet) being preferred. When the sheet S is a paper sheet, base paper made primarily of pulp is used. The pulp composition can be any known composition for paper sheets. For example, the pulp content can be 50% by mass or more, preferably 90% by mass or more, and more preferably 100% by mass.

Furthermore, the pulp composition of the sheet S (paper sheet) is not particularly limited. For example, softwood pulp such as NBKP (softwood kraft pulp) or NUKP (softwood unbleached pulp) and hardwood pulp such as LBKP (hardwood kraft pulp) or LUKP (hardwood unbleached pulp) can be used in any ratio.

The ratio of hardwood pulp to softwood pulp in sheet S (paper sheet) is not limited, but is preferably 10:90 to 80:20, and more preferably a pulp composition in which the ratio of softwood pulp to hardwood pulp is higher. Furthermore, recycled paper pulp may also be used as the pulp contained in sheet S (paper sheet).

The basis weight of the sheet S is not particularly limited, but in the case of paper, it is 5 g/ ^m2 or more and 80 g/m2 or ^less , preferably 10 g/ ^m2 or more and 60 g/ ^m2 or less, and more preferably 10 g/m2 or ^more and 45 g/m2 or ^less , depending on the number of plies. In the case of nonwoven fabric, it is desirable that it is 20 g/m2 or ^more and 100 g/m2 or ^less . The basis weight is measured in accordance with the provisions of JIS P 8124 (2011).

The thickness of the sheet S (paper sheet) is not particularly limited, and the paper thickness measured under the conditions specified in JIS P 8111 (1998) can be used. For example, if the sheet S is paper, the paper thickness per two plies is 50 μm or more and 600 μm or less, preferably 60 μm or more and 500 μm or less, and more preferably 130 μm or more and 400 μm or less.

The sheet S (paper sheet) may also be embossed. Such embossing can be performed using a known embossing method.

The shape of the packaging bag 10 is not particularly limited. In this embodiment, it has a top surface 11, a bottom surface 12, side surfaces 13 and 14, end surfaces 15 and 16. In the packaging bag 10, the top surface 11 and the bottom surface 12 face each other in the vertical direction (Z direction), the side surfaces 13 and 14 face each other in the width direction (Y direction), and the end surfaces 15 and 16 face each other in the longitudinal direction (X direction). Furthermore, the end surfaces 15 and 16 are continuous with all of the top surface 11, bottom surface 12, side surfaces 13, and side surfaces 14 (Figs. 1, 3 to 8).

The dimensions of the packaging bag 10 are not particularly limited. For example, the length L1 of the packaging bag 10 in the longitudinal direction (X direction) can be approximately 150 to 250 mm, the width W1 in the width direction (Y direction) perpendicular to the longitudinal direction (X direction) of the packaging bag 10 can be approximately 70 to 150 mm, and the height H1 in the height direction (Z direction) can be approximately 20 to 100 mm (Figures 1 and 3). Note that the dimensions of the packaging bag 10 refer to the dimensions when the sheet laminate 20 is contained in the packaging bag 10 (Figures 1 and 2).

The top surface 11 of the packaging bag 10, the top surface 11 side of the end surface 15, and the top surface 11 side of the end surface 16 are provided with access openings extending in the longitudinal direction (X direction) of the packaging bag 10. Specifically, the access openings have tear-open score lines 30 formed therein. The tear-open score lines 30 are score lines in which cuts C and ties T (two cuts C and the uncut portion between C) are arranged alternately, and when a tie T is broken, the adjacent cuts C on both sides become continuous cuts (Figures 1, 3, 7, and 8).

In this embodiment, the tearing score line 30 forms a linear perforation M in which cuts C and ties T are arranged alternately (Figs. 1, 3, 7, and 8). The ratio of ties T to cuts C in the tearing score line 30 (perforation) is arbitrary, but can be, for example, 1:1 to 1:7, preferably 1:1.3 to 1:5, and more preferably 1:1.5 to 3.

In the packaging bag 10 of this embodiment, tearing along the tearing score line 30 (perforation M) forms an opening (opening OP) on the top surface 11 of the packaging bag 10 through which the sheet S can be pulled out (Figs. 1 and 10).

The tear score line 30 can be created by any method. For example, although not shown, the base material BS of the packaging bag 10 (described below) can be placed between the needle and the base, and the tip of the needle can be inserted into the receiving groove of the base to form the tear score line 30.

Ventilation holes (not shown) may be formed in the packaging bag 10. The ventilation holes can function as air holes for the packaging bag 10. The location of the ventilation holes is not particularly limited, and in this embodiment, ventilation holes can be provided on the side surfaces 13, 14, and end surfaces 15 and 16 of the packaging bag 10. The number of ventilation holes is not limited. The shape of the ventilation holes is also not limited, and may be, for example, circular in plan view. The dimensions of the ventilation holes are also not limited, and may be, for example, a diameter of approximately 2 mm.

The method for creating the ventilation hole is arbitrary. For example, similar to the tearing score line 30 described above, the ventilation hole can be created by placing the base material BS of the packaging bag 10 between the needle and the base, and inserting the tip of the needle into the receiving groove in the base. When creating a ventilation hole, a base without a receiving groove may also be used.

By providing such ventilation holes in the packaging bag 10, the packaging bag is less likely to burst during storage or transportation of the sheet packaging body 100.

The packaging form of the packaging bag 10 is not particularly limited, and can be, for example, a pillow packaging bag in which the base material BS of the packaging bag 10 is processed into a cylindrical shape and the open end of the cylindrical base material BS is sealed, a caramel packaging bag in which both ends of the cylindrical packaging bag 10 sheet are folded and sealed, or a combination of these. In the case of a pillow packaging bag, the cylindrical base material BS may be folded into a gusset shape.

In this embodiment, the packaging bag 10 is a pillow packaging bag having at least one seal portion. Specifically, seal portions (end seals) 40, 50 are formed on the end faces 15, 16 of the packaging bag 10, and a seal portion (bottom seal) 60 is formed on the bottom surface 12 of the packaging bag 10, thereby pillow-packaging the sheet S (sheet stack 20).

In the packaging bag 10 of this embodiment, the seal portions 40, 50, and 60 are heat-sealed. Here, heat-sealing refers to heating a part of the base material BS to weld parts of the packaging bag sheet together. Specifically, the seal portions 40, 50, and 60 are heat-sealed with an inner layer (resin layer) 10B of the base material BS, which will be described later, disposed inside the packaging bag 10.

In the packaging bag 10, the joining pitch of the sealed portion 40, the joining pitch of the sealed portion 50, and the joining pitch of the sealed portion 60 are each preferably 0.5 mm or more and 2 mm or less, more preferably 0.8 mm or more and 1.8 mm or less, and even more preferably 1.0 mm or more and 1.5 mm or less.

Here, the joining pitch refers to the spacing in a predetermined direction (the width direction (Y direction) of the packaging bag 10 for the seal portions 40, 50, 60, and the longitudinal direction (X direction) of the packaging bag 10 for the seal portions 40, 50, 60) of the portions (not shown) that are bonded in a convex shape when viewed from one side (e.g., the bottom surface 12 side of the packaging bag 10) of the seal portions 40, 50, 60.

In this embodiment, as described above, by setting the joining pitch of the seal portions (seal portions 40, 50, 60) to 0.5 mm or more and 2 mm or less, the adhesive function of the inner layer (resin layer 10B) provided on the base layer (paper layer) 10A (described below) can be improved, resulting in a packaging bag 10 (pillow packaging bag) with better sealing properties.

The packaging bag 10 is made of a base material BS containing a paper component. Here, the paper component is agglutinated plant fibers (pulp). The pulp composition of the paper component is not limited, and for example, the ratio of hardwood pulp to softwood pulp is 0:100 to 70:30, and preferably the pulp composition has a higher ratio of softwood pulp to hardwood pulp. Furthermore, recycled paper pulp may also be used as the pulp.

The substrate BS that constitutes the packaging bag 10 of the first embodiment is composed of a base layer 10A, an inner layer 10B, and an outer layer 10C. The substrate BS in the first embodiment has a three-layer structure in which the inner layer 10B and the outer layer 10C are laminated on each side of the paper layer 10A (Figure 9).

The base layer 10A forms the base of the substrate BS. The base layer 10A also forms a paper layer containing the above-mentioned paper components.

The material of the paper component contained in the base layer (paper layer) 10A is not particularly limited, but it can be made of, for example, kraft paper or rayon paper.

Kraft paper is paper made from kraft pulp. Rayon paper is made by blending rayon fiber, which is chemically synthesized from wood pulp, with kraft pulp. To ensure that the packaging bag 10 is both soft and strong, it is preferable that the rayon fiber content of the rayon paper be 20% or less by mass.

The basis weight of the base layer (paper layer) 10A is not limited, but is preferably 10 g/m ² or more and 70 g/m ² or less, more preferably 15 g/m ² or more and 60 g/m ² or less, and even more preferably 20 g/m ² or more and 50 g/m ² or less. The basis weight is measured in accordance with the provisions of JIS P 8124 (2011).

The thickness of the base layer (paper layer) 10A is not limited, but is preferably 20 μm or more and 300 μm or less, more preferably 30 μm or more and 200 μm or less, and even more preferably 40 μm or more and 180 μm or less. The thickness is measured in accordance with the provisions of JIS P 8118 (2014).

The tensile strength of the base layer (paper layer) 10A is not limited, but is, for example, 500 cN/m or more and 20,000 cN/m or less, preferably 1,000 cN/m or more and 15,000 cN/m or less , and more preferably 1,500 cN/m or more and 12,000 cN/m or less in the longitudinal direction of the fibers (machine direction or MD direction).

The tensile strength in the cross direction (the direction perpendicular to the machine direction or the CD) of the fibers is 100 cN/m or more and 10,000 cN/m or less, preferably 300 cN/m or more and 5,000 cN/m or less , more preferably 500 cN/m or more and 2,500 cN/m or less. The tensile strength is measured in accordance with the provisions of JIS P 8113 (2006).

The elongation of the base layer (paper layer) 10A is not limited, but is, for example, 0.5% to 30% in the machine direction (MD), preferably 1% to 25%, and more preferably 2% to 20%. Also, the elongation in the cross direction (CD) is 0.5% to 20%, 1% to 10%, or 2% to 5%. The elongation is measured in accordance with JIS P 8113 (2006).

The tear strength of the base layer (paper layer) 10A is not limited, but is, for example, 50 mN to 500 mN in the longitudinal direction of the fibers (MD direction), preferably 80 mN to 480 mN , and more preferably 100 mN to 450 mN.

The tear strength in the cross direction (CD) of the fibers is 200 mN or more and 1000 mN or less, preferably 250 mN or more and 900 mN or less , and more preferably 300 mN or more and 800 mN or less. The tear strength is measured in accordance with the provisions of JIS P 8116 (2000).

The inner layer 10B is laminated on one or the other side of the base layer (paper layer) 10A and constitutes a resin layer containing a thermoplastic resin. The inner layer (resin layer) 10B is disposed on the inside of the packaging bag 10. Here, the inside of the packaging bag 10 refers to the side of the substrate BS that contacts the sheet S contained in the packaging bag 10 (i.e., the side on which the sheet S is contained in the packaging bag 10 or the side on which the inner layer 10B of the substrate BS is formed).

The inner layer 10B constitutes the inner surface IS of the substrate BS that is placed inside the packaging bag 10 (the side where the sheet S is placed in the packaging bag 10). The inner surface IS of the substrate BS that is placed inside the packaging bag 10 corresponds to the side of the substrate BS that comes into contact with the sheet S placed in the packaging bag 10 (i.e., the side of the substrate BS on which the inner layer 10B is formed or the side opposite the side on which the outer layer of the substrate BS is formed).

The thermoplastic resin material contained in the inner layer (resin layer) 10B is not particularly limited, but is preferably low-density polyethylene. The low-density polyethylene may be either high-pressure low-density polyethylene (LDPE) or linear low-density polyethylene (L-LDPE).

The thickness of the inner layer (resin layer) 10B is not limited, but is preferably 5 μm to 40 μm, more preferably 7 μm to 35 μm, and even more preferably 9 μm to 30 μm. The paper thickness is measured in accordance with JIS P 8118 (2014).

The thermoplastic resin contained in the inner layer (resin layer) 10B contains a slip agent. Here, the slip agent is an agent that reduces the coefficient of friction of the surface (inner surface) of the inner layer 10B. In this embodiment, the slip agent is added to the thermoplastic resin contained in the inner layer (resin layer) 10B, but it may also be coated on the inner surface IS of the substrate BS.

The components of the slip agent are not particularly limited, but for example, ethylene homopolymer, fatty acid amide, vegetable oil, etc. can be used as the main component. The amount of slip agent relative to the thermoplastic resin is not particularly limited. In addition to the main component, the slip agent may also contain additives for purposes such as maintaining the stability of the slip agent.

The outer layer (printed layer) 10C is provided on one or the other side of the paper layer 10A and constitutes a printed layer that is printed on the surface of the packaging bag. The outer layer (printed layer) 10C is disposed on the outside of the packaging bag 10. Here, the outside of the packaging bag 10 refers to the side where the base material BS does not come into contact with the sheet S contained in the packaging bag 10 (i.e., the side opposite the side where the sheet S is contained in the packaging bag 10 or the side where the inner layer 10B of the base material BS is formed).

The outer layer (printed layer) 10C constitutes the outer surface OS of the substrate BS that is placed on the outside of the packaging bag 10 (the side opposite the side on which the sheet S is placed in the packaging bag 10). The outer surface OS of the substrate BS that is placed on the outside of the packaging bag 10 corresponds to the side that does not come into contact with the sheet S placed in the packaging bag 10 (i.e., the side on which the outer layer 10C of the substrate BS is formed or the side opposite the side on which the inner layer 10B of the substrate BS is formed).

The outer layer (printed layer) 10C contains a gripping agent. Here, the gripping agent is an agent that increases the coefficient of friction of the surface (outer surface) of the outer layer 10C. In this embodiment, the gripping agent is applied to the outer surface OS of the substrate BS, but it may also be contained in the outer layer (printed layer) 10C.

The ingredients of the gripping agent are not particularly limited, but for example, medium ink (synthetic resin), oil-based varnish, etc. can be used as the main ingredient. The amount of gripping agent used relative to the outer layer (printed layer) 10C is not particularly limited. In addition to the main ingredient, the gripping agent may also contain auxiliary agents and solvents for purposes such as maintaining the stability of the gripping agent.

In this embodiment, the ratio of paper components in the packaging bag 10 (substrate BS) is 50% or more.

The basis weight of the packaging bag 10 (substrate BS) is not limited, but is preferably 20 g/m ² or more and 100 g/m ² or less, more preferably 25 g/m ² or more and 70 g/m ² or less, and even more preferably 30 g/m ² or more and 60 g/m ² or less. The basis weight is measured in accordance with the provisions of JIS P 8124 (2011).

The thickness (paper thickness) of the packaging bag 10 (substrate BS) is not limited, but is, for example, 25 μm or more and 350 μm or less, preferably 30 μm or more and 250 μm or less, and more preferably 45 μm or more and 200 μm or less. The thickness may be measured in accordance with the provisions of JIS P 8118 (2014).

The tensile strength of the packaging bag 10 (substrate BS) is not limited, but is, for example, 1000 cN/m or more and 20,000 cN/m or less in the longitudinal direction of the fibers (MD direction), preferably 1500 cN/m or more and 18,000 cN/m or less , and more preferably 2000 cN/m or more and 15,000 cN/m or less.

The tensile strength in the cross direction (CD) of the fibers is 500 cN/m or more and 10,000 cN/m or less, preferably 1,000 cN/m or more and 8,000 cN/m or less , and more preferably 1,500 cN/m or more and 5,000 cN/m or less. The tensile strength is measured in accordance with the provisions of JIS P 8113 (2006).

The elongation of the packaging bag 10 is not limited, but is, for example, 0.5% to 30% in the longitudinal direction of the fibers (MD direction), preferably 1% to 25% in the longitudinal direction, and more preferably 2% to 20% in the transverse direction of the fibers (CD direction). It is also 0.5% to 20% in the transverse direction of the fibers (CD direction), 1% to 10%, or 2% to 5%. Elongation is measured in accordance with the provisions of JIS P 8113 (2006).

The tear strength of the packaging bag 10 is not limited, but is, for example, 50 mN or more and 500 mN or less, preferably 80 mN or more and 450 mN or less , and more preferably 100 mN or more and 400 mN or less in the longitudinal direction of the fibers (MD direction).

The tear strength in the cross direction (CD) of the fibers is 200 mN or more and 1000 mN or less, preferably 250 mN or more and 900 mN or less , and more preferably 300 mN or more and 800 mN or less. The tear strength is measured in accordance with the provisions of JIS P 8116 (2000).

The Taber stiffness of the packaging bag 10 is not limited, but is, for example, 0.01 mN/m or more and 0.2 mN/m or less in the longitudinal direction of the fibers (MD direction), preferably 0.02 mN/m or more and 0.17 mN/m or less, and more preferably 0.03 mN/m or more and 0.15 mN/m or less.

The stiffness in the cross direction (CD) of the fibers is 0.001 mN/m or more and 0.1 mN/m or less, preferably 0.01 mN/m or more and 0.08 mN/m or less, and more preferably 0.02 mN/m or more and 0.07 mN/m or less. The Taber stiffness is measured in accordance with the provisions of JIS P 8125 (2000).

In the packaging bag 10 of this embodiment, a first static friction coefficient A occurs between the inner surface IS of the substrate BS (the inner surface IS on the side where the inner layer 10B of the substrate BS is formed) arranged inside the packaging bag 10 and the sheet S (sheet stack 20).

In addition, a second static friction coefficient B occurs between the outer surface OS of the substrate BS arranged on the outside of the packaging bag 10 (the outer surface OS on the side on which the outer layer 10C of the substrate BS is formed) and the artificial skin (not shown).

Furthermore, the second static friction coefficient B is greater than the first static friction coefficient A. And the first static friction coefficient A is 0.55 or less.

Here, the static friction coefficient refers to the ratio of the frictional force generated at the contact surface between two objects when there is no relative motion to the force acting perpendicular to the contact surface. The static friction coefficient is measured in accordance with the horizontal method provisions of JIS P 8147 (2010). Furthermore, artificial skin refers to a molded product made of urethane elastomer that mimics human skin.

In this embodiment, the substrate BS of the packaging bag 10 includes a base layer 10A containing a paper component and an outer layer 10C laminated on either side of the base layer 10A and positioned on the outside of the packaging bag 10. The outer layer 10C contains a gripping agent, which increases the frictional force generated between the outer layer 10C of the substrate BS and the fingers of a person touching the outer layer 10C of the substrate BS (hereinafter referred to as fingers). This makes it less likely for fingers touching the substrate BS to slip against the substrate BS. Therefore, when a sheet S is provided on a paper packaging bag 10, the sheet S is more easily torn, making it easier to open even a paper packaging bag 10 (FIGS. 1 and 10).

In this embodiment, the second static friction coefficient B between the outer surface of the substrate on which the outer layer is formed and the artificial skin is made larger than the first static friction coefficient A between the inner surface IS of the substrate BS placed inside the packaging bag 10 and the sheet S. This makes the friction force between the outer surface OS of the substrate BS and the artificial skin relatively larger than the friction force between the inner surface IS of the substrate BS and the sheet S. This makes it easier to tear the perforations M provided in the paper packaging bag 10, making it easier to open the packaging bag 10 (Figures 1 and 10).

In this embodiment, the first static friction coefficient A between the inner surface IS of the substrate BS placed inside the packaging bag 10 and the sheet S is 0.55 or less, making the inner surface IS of the substrate BS, which contains a paper component, slippery relative to the sheet S. This makes it even easier to tear the perforations M on the paper packaging bag 10, making it even easier to open the packaging bag 10 (Figs. 1 and 10).

In the packaging bag 10 of this embodiment, it is preferable that the ratio of the first static friction coefficient A to the second static friction coefficient B be 0.65 or less. Here, the ratio of the first static friction coefficient A to the second static friction coefficient B indicates the ratio of the first static friction coefficient A to the second static friction coefficient.

In this embodiment, by setting the ratio of the first static friction coefficient A to the second static friction coefficient B to 0.65 or less, the difference between the friction coefficient of the inner surface IS of the substrate BS against the sheet S contained in the packaging bag 10 and the friction coefficient of the outer surface OS of the substrate BS against the artificial skin (not shown) becomes larger. This makes it easier to tear the perforations M provided in the paper packaging bag 10, making it easier to open the packaging bag 10.

In the packaging bag 10 of this embodiment, the second static friction coefficient is preferably 1.1 or less. In paper packaging bags, the difference between the first static friction coefficient and the second friction coefficient should be as large as possible to improve ease of opening. On the other hand, if the second friction coefficient is too large relative to the first static friction coefficient, there is a risk that the perforations in the paper packaging bag will tear before the packaging bag is opened (for example, during the manufacturing, distribution, or storage of the sheet packaging body 100 using the packaging bag 10).

In this embodiment, the second static friction coefficient B is adjusted to be 1.1 or less so that the outer surface OS of the base material BS does not become too slippery, thereby preventing unexpected tearing of the packaging bag 10 without reducing the ease of opening the packaging bag 10.

In the packaging bag 10 of this embodiment, the first static friction coefficient A corresponds to the static friction coefficient between the CD direction of the substrate BS and the MD direction of the sheet S. Furthermore, the second static friction coefficient B corresponds to the static friction coefficient between the CD direction of the substrate BS and the artificial skin.

In this embodiment, the MD direction of the substrate BS corresponds to the longitudinal direction (X direction) of the packaging bag 10, and the CD direction of the substrate BS corresponds to the width direction (Y direction) of the packaging bag 10 (Figures 1, 3 to 8). Furthermore, the MD direction of the sheet S corresponds to the width direction (Y direction) of the packaging bag 10 or the sheet stack 20, and the CD direction of the sheet S corresponds to the longitudinal direction (X direction) of the packaging bag 10 or the sheet stack 20 (Figures 1 and 2).

In this embodiment, the static friction coefficient between the CD direction of the substrate BS and the MD direction of the sheet S is set to a first static friction coefficient A, making it easier for the CD direction of the substrate BS to slide relative to the MD direction of the sheet S. Furthermore, by setting the static friction coefficient between the CD direction of the substrate BS and the artificial skin to a second static friction coefficient, the artificial skin becomes less likely to slide relative to the CD direction of the substrate BS.

In this embodiment, when sheet S is placed in packaging bag 10 so that the MD direction of sheet S is aligned with the CD direction of base material BS and perforations M are formed in the MD direction of base material BS, pressing the surface of packaging bag 10 on which perforations M are formed (top surface 11) with the thumbs of both hands and moving the thumbs apart in the CD direction of base material BS causes perforations M to tear (Figures 1 and 10). At this time, the perforations tear easily with little force, making it even easier to open packaging bag 10 (top surface 11).

As described above, in the packaging bag 10 of this embodiment, a tearing score line 30 (perforation M) is formed on the top surface 11 of the packaging bag 10 along the MD direction of the base material BS.

In this embodiment, by forming a tearing score line 30 (perforation M) along the MD direction of the base material BS on the top surface 11 of the packaging bag 10, the tearing score line 30 (perforation M) can be torn by simply pressing the top surface 11 of the packaging bag 10 with the thumbs of both hands and moving the thumbs apart in the CD direction of the base material BS, making it easy to open the packaging bag 10.

In addition, in this embodiment, the torn tear score line 30 (perforation M) can form a sheet removal opening (opening OP) formed on the top surface 11 of the packaging bag 10 (Figs. 1 and 10). This makes it possible to remove the sheet S from the top surface 11 of the packaging bag 10.

In this embodiment, the tearing score line 30 (perforation M) is formed along the MD direction of the substrate BS and the CD direction of the sheet S, and the static friction coefficient is measured in a direction perpendicular to the direction in which the perforation M extends (the CD direction of the substrate BS and the MD direction of the sheet S). However, the orientation of the sheet S and substrate BS for measuring the static friction coefficient is not limited. For example, the tearing score line 30 (perforation M) may be formed along the CD direction of the substrate BS and the MD direction of the sheet S, and the static friction coefficient may be measured in a direction perpendicular to the direction in which the perforation M extends (the MD direction of the substrate BS and the CD direction of the sheet S).

In addition, in this embodiment, as described above, the case where sheet S is placed in packaging bag 10 so that the MD direction of sheet S is aligned with the CD direction of base material BS has been described, but the relationship between the MD direction of sheet S and the CD direction of base material BS is not limited. In other words, the direction in which sheet S is placed in packaging bag 10 is not limited. For example, sheet S may be placed in packaging bag 10 so that the MD direction of sheet S is aligned with the MD direction of base material BS.

The sheet packaging body 100 of this embodiment can use the packaging bag 10 described above. Specifically, the sheet packaging body 100 has a packaging bag 10 (the packaging bag of the first embodiment) and a sheet S contained in the packaging bag 10 (FIGS. 1 and 2).

The sheet packaging body 100 of this embodiment is configured as a sheet packaging body in which a sheet S is housed in the packaging bag 10 described above, thereby achieving the same effects as the packaging bag 10 described above. That is, in the sheet packaging body 100 of this embodiment, even if the packaging bag 10 constituting the sheet packaging body 100 is made of paper, the perforations M provided in the paper packaging bag 10 are easily torn, making it easy to open even a paper packaging bag (Figs. 1 and 10).

As described above, in the packaging bag 10 of this embodiment, an inner layer (resin layer) 10B containing a thermoplastic resin is provided on either side of the base layer (paper layer) 10A containing a paper component, which gives the packaging bag 10 a soft texture. This reduces the stiffness of the packaging bag 10 and provides conformability to the packaging bag 10. Therefore, even if the material of the packaging bag is changed from resin to paper, it is possible to provide a packaging bag 10 that is less likely to break during manufacturing or transportation.

Furthermore, in this embodiment, the packaging bag 10 has conformability due to the inner layer (resin layer) 10B laminated to the base layer (paper layer) 10A, and the tearing score line 30 is provided on the packaging bag 10, making it easy to tear the tearing score line 30.

In addition, in this embodiment, the inner layer (resin layer) 10B provided on one or other surface of the base layer (paper layer) 10A contains a thermoplastic resin. Therefore, by heating the inner layer (resin layer) 10B when sealing (or sealing) the packaging bag 10, the melted inner layer (resin layer) 10B can function as an adhesive (have an adhesive function), making it easy to seal the packaging bag 10.

Furthermore, in this embodiment, the ratio of paper components in the packaging bag 10 is 50% or more, which helps reduce the environmental impact.

In this embodiment, as described above, by setting the thickness of the inner layer (resin layer) 10B to be between 5 μm and 40 μm, it becomes easier to maintain the paper component ratio of the packaging bag at 50% or more. Furthermore, the adhesive function of the inner layer (resin layer) 10B can be maintained when the packaging bag is sealed, while suppressing the stiffness of the packaging bag.

In this embodiment, as described above, by using low-density polyethylene as the thermoplastic resin contained in the inner layer (resin layer) 10B, the stiffness of the packaging bag 10 can be further reduced while improving the adhesive function of the inner layer (resin layer) 10B when sealing the packaging bag 10.

In this embodiment, as described above, the packaging bag 10 is a pillow packaging bag, and with the inner layer (resin layer) 10B positioned inside the packaging bag 10, at least one seal portion is heat-sealed to bond the resin layers together. This makes it possible to effectively utilize the adhesive function of the inner layer (resin layer) 10B, resulting in a packaging bag 10 with high sealing properties.

In this embodiment, by providing a tear score line 30 on the packaging bag 10, the packaging bag 10 can be opened simply by tearing the tear score line 30. The torn tear score line 30 can also form an access opening (opening OP) for the packaging bag 10. Furthermore, in this embodiment, the tear score line 30 is provided on a packaging bag 10 that has conformability due to the inner layer (resin layer) 10B being laminated on the paper layer 10A, so the tear score line 30 can be easily torn.

The present invention will now be described in further detail using examples. The examples and comparative examples were evaluated using the following tests.

[Test specimen]
As a test sample, a sheet package 100 was prepared in which a plurality of sheets S (sheet stack 20) were pillow-packaged in a paper packaging bag 10 (FIGS. 1 to 8).

The packaging bag 10 is composed of a base material BS, which is composed of a base layer 10A, an inner layer 10B, and an outer layer 10C (Figure 9). The inner layer 10B is made of low-density polyethylene (PE). The outer layer 10C is a gravure-printed layer. A tear-open score line 30 (perforation M) is formed on the top surface 11 of the packaging bag 10, extending from seal portion 40 to seal portion 50 in the longitudinal direction (MD) of the packaging bag 10. The ratio of ties T to cuts C in the perforation M is 1:2 in the example and 1:5 in the comparative example.

The sheet stack 20 used single (1-ply) paper towels (product name "Elveil Paper Towel Eco Dry (medium size)", manufactured by Daio Paper Co., Ltd., 200 sets, height H1: 65 mm, length L1: 210 mm, width (depth) W1: 115 mm, basis weight 33 g/ ^m2 , paper thickness 180 μm) and double-type paper towels (product name "Elleair Paper Towel Smart Type Double (medium size)", manufactured by Daio Paper Co., Ltd., 200 sets, height H1: 60 mm, length L1: 210 mm, width (depth) W1: 115 mm, basis weight 16 g/ ^m2 x 2) as paper towels in which the sheets S are stacked in a folded state.

[Yonetsubo]
The basis weight (grammage) of the base material (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging body 100) was measured in accordance with the provisions of JIS P 8124 (2011). The unit of basis weight is g/ ^m² .

[Paper thickness]
The thickness (thickness) of the substrate (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging body 100) was measured using an ISO paper thickness meter (MEI-11, manufactured by CITIZEN) in accordance with the provisions of JIS P 8118 (2014). The unit of thickness is μm.

[Tensile strength]
The tensile strength (mN) in the longitudinal direction (MD direction) and transverse direction (CD direction) of the substrate (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging body 100) was measured using a Tensilon universal testing machine (manufactured by A&D Co., Ltd., RTG-1210) in accordance with the provisions of JIS P 8113 (2006).

[stretch]
The elongation (%) in the longitudinal direction (MD direction) and transverse direction (CD direction) of the substrate (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging body 100) was measured using a Tensilon universal testing machine (manufactured by A&D Co., Ltd., RTG-1210) in accordance with the provisions of JIS P 8113 (2006).

[Tear strength]
The tear strength of the substrate (all layers) BS and base layer 10A of the packaging bag 10 in the test specimen (sheet packaging body 100) in the longitudinal direction (MD direction) and transverse direction (CD direction) of the fibers was measured using a tear strength tester (Elmendorf tear strength tester (digital display type) manufactured by Kumagai Riki Kogyo Co., Ltd.) in accordance with the provisions of JIS P 8116 (2000).

[Taber stiffness]
The Taber stiffness of the substrate (all layers) BS of the packaging bag 10 in the test specimen (sheet packaging body 100) was measured in accordance with the provisions of JIS P 8125 (2000). The Taber stiffness was measured using a Taber stiffness tester (manufactured by Toyo Seiki Seisakusho, Ltd.).

[Static friction coefficient]
The static friction coefficient was measured in accordance with the horizontal method of JIS P 8147 (2010) using a load cell tensile tester (AGS-500B, manufactured by Shimadzu Corporation).

Specifically, the static friction coefficient A1 between the CD direction of the inner surface IS (inner layer 10B) of the base material BS of the packaging bag 10 and the MD direction of the sheet S (single web) in the test specimen (sheet packaging body 100), the static friction coefficient A2 between the CD direction of the inner surface IS (inner layer 10B) of the base material BS of the packaging bag 10 and the MD direction of the sheet S (double web), and the static friction coefficient B between the CD direction of the outer surface OS (outer layer 10C) of the base material BS of the packaging bag 10 and artificial skin (Bioskin Plate, No. 132#BSC, thermoplastic urethane elastomer, manufactured by Viewlux Corporation) were measured.

When measuring the static friction coefficients A1 and A2, the substrate BS was fixed to the horizontal plate side of the friction tester so that the CD direction of the inner surface (inner layer 10B) of the substrate BS was facing outward, and the sheet S was fixed to the weight side of the friction tester so that the MD direction of the front surface of the sheet S was facing outward.

To measure the static friction coefficient B, the substrate BS was fixed to the horizontal plate of the friction tester so that the CD direction of the outer surface OS (outer layer 10C) of the substrate BS was facing outward. The artificial skin was cut to a size of 100 mm long x 100 mm wide x 5 mm thick to fit the weight side of the friction tester, and attached to the weight side of the friction tester so that the measurement surface was facing outward (non-glossy side).

If the dimensions of the test piece are insufficient, you can join the back side of the test piece (the side not being measured) with a paper-based sealant or similar material. In this case, be careful not to create wrinkles or sagging.

[Ease of opening perforations]
The ease of opening the perforation M (tear-opening score line 30) formed on the top surface 11 of the packaging bag 10 of the test specimen (sheet packaging body 100) was confirmed. The test was conducted for both cases where a single-type sheet S (web) was housed in the packaging bag 10 and where a double-type paper towel sheet was housed. The ease of opening the perforation in the sheet packaging body 100 was evaluated by having 10 users hold the surface (top surface 11) of the packaging bag 10 on which the perforation M was formed with the thumbs of both hands and move their thumbs apart in the CD direction of the base material BS. If 0 to 3 people answered that it was difficult to open, the evaluation was rated as ◯ (good), and if 4 or more people answered that it was difficult to open, the evaluation was rated as × (poor). The evaluation criteria were as follows:
A: Perforation M is easy to tear B: Perforation M can be torn C: Perforation cannot be torn, or can be torn but is difficult to tear

The following describes examples and comparative examples.

[Example 1]
When PE with added slip agent was used for inner layer 10B of substrate BS of packaging bag 10 and a gripping agent (varnish) was applied to outer layer 10C, and the static friction coefficient A1 was 0.42, the static friction coefficient A2 was 0.38, and the static friction coefficient B was 0.96, the ease of opening the perforations was rated A for both single and double bags. The conditions of packaging bag 10, the conditions of the sheet (web), and the evaluation results (static friction coefficient and ease of opening the perforations) are shown in Table 1.

[Example 2]
The static friction coefficient A1 was 0.46, the static friction coefficient A2 was 0.45, and the static friction coefficient B was 0.95, and the evaluation was the same as in Example 1, and the ease of opening the perforation was rated B for both single and double. The conditions of the packaging bag 10, the conditions of the sheet (web), and the evaluation results are shown in Table 1.

[Example 3]
The static friction coefficient A1 was 0.41, the static friction coefficient A2 was 0.37, and the static friction coefficient B was 0.8, and the evaluation was the same as in Example 1, and the ease of opening the perforation was rated A for both single and double. The conditions of the packaging bag 10, the conditions of the sheet (web), and the evaluation results are shown in Table 1.

[Comparative Example 1]
When no slip agent was added to the PE used in the inner layer 10B of the base material BS of the packaging bag 10, no grip agent (varnish) was applied to the outer layer 10C, the static friction coefficient A1 was 0.57, the static friction coefficient A2 was 0.69, and the static friction coefficient B was 1.2, the ease of opening the perforations was rated C for both single and double bags. The conditions of the packaging bag 10, the conditions of the sheet (web), and the evaluation results are shown in Table 1.

[Reference example 1]
A sheet package was prepared in which multiple sheets S (sheet laminate 20) were pillow-packaged in a packaging bag made of resin film, and when the static friction coefficient A1 was 0.3, the static friction coefficient A2 was 0.27, and the static friction coefficient B was 1.14, the ease of opening the perforations was rated A for both single and double. The conditions of the packaging bag, the conditions of the sheet (web), and the evaluation results are shown in Table 1.

Table 1 shows that the test specimens in which the substrate BS included a base layer 10A containing a paper component and an outer layer 10C laminated on one side of the base layer 10A and positioned on the outside of the packaging bag 10, and in which the outer layer 10C contained a gripping agent, exhibited good ease of opening the perforations (Examples 1 to 3).

In contrast, the test specimen in which the outer layer 10C of the substrate BS did not contain a gripping agent exhibited poor ease of opening the perforations (Comparative Example 1).

In other words, this embodiment is a packaging bag that contains a sheet and is made of a base material containing a paper component, and in the base material that has a tearing score line formed thereon for removing at least the sheet from the packaging bag, the static friction coefficient between the outer surface of the base material and the fingers (or artificial skin) of the person tearing the tearing score line is greater than the static friction coefficient between the inner surface of the base material and the sheet. Therefore, when tearing the tearing score line, the fingers do not slip, making it difficult to tear.

A substrate with such a static friction coefficient may be formed over the entire surface of the packaging bag, or may be formed only on the surface on which the tearing score line is formed (for example, the top surface of the packaging bag). Furthermore, it is also possible to make the static friction coefficient between a portion of the substrate, where the fingers come into contact when tearing the tearing score line, and a human finger (or artificial skin) greater than the static friction coefficient between the inner surface of the substrate and the sheet.

Although the above describes an embodiment of the present invention, the present invention is not limited to a specific embodiment, and various modifications and variations are possible within the scope of the invention described in the claims.

100 Sheet packaging body 10 Packaging bag BS Base material IS Inner surface OS Outer surface 10A Base layer (paper layer)
10B Inner layer (resin layer)
10C outer layer (printing layer)
11 Top surface 12 Bottom surface 13, 14 Side surfaces 15, 16 End surfaces 20 Sheet laminate S Sheet 30 Cut line for tearing M Perforation OP Take-out port (opening)
40, 50 Seal section (end seal)
60 Seal part (bottom seal)
L1, L2 Length W1, W2 Width H1, H2 Height

Claims (5)

A packaging bag for containing a sheet,
It is made up of a base material containing paper components,
The substrate is
a base layer comprising the paper component;
an outer layer laminated on either one surface of the base layer and disposed on the outside of the packaging bag;
the outer layer comprises a gripping agent;
The tear strength in the lateral direction of the packaging bag is 300 mN or more and 800 mN or less,
a first static friction coefficient between the sheet and an inner surface of the substrate disposed inside the packaging bag;
a second static friction coefficient between the outer surface of the substrate on which the outer layer is formed and the artificial skin;
the second coefficient of static friction is greater than the first coefficient of static friction;
the first static friction coefficient is 0.55 or less;
a ratio of the first static friction coefficient to the second static friction coefficient is 0.4 or more and 0.51 or less;
packaging bag. The second static friction coefficient is 1.1 or less.
The packaging bag according to claim 1 . The first static friction coefficient is a static friction coefficient between the CD direction of the substrate and the MD direction of the sheet,
The second static friction coefficient is the static friction coefficient between the substrate in the CD direction and the artificial skin.
The packaging bag according to claim 1 or 2 . A tearing score line is formed on the top surface of the packaging bag along the MD direction of the base material.
The packaging bag according to claim 3 . The packaging bag according to any one of claims 1 to 4 ,
A sheet contained in the packaging bag.
Sheet packaging.