JP7484105B2 - Paper container with zipper and its manufacturing method - Google Patents

Description

The present invention relates to a paper container with a zipper, particularly in the field of paper containers that have a three-dimensional shape and are self-supporting, and relates to a paper container with a zipper that can maintain its beauty by preventing damage to the laminated sheet on the protruding part (edge) on the top surface.

Conventionally, technology such as that disclosed in Patent Document 1 has been disclosed as a paper container with a zipper. That is, a zipper is provided on the top of a rectangular parallelepiped paper container, and the zipper can be opened when the contents are to be removed, and closed when the contents have been removed.

The above technology can protect the contents and prevent them from spilling when the paper container is tipped over. In addition, because the container is made of paper, it is easy to reduce the volume of the container and dispose of it after the contents have been consumed. Figure 1 shows a blank plate 95 used to manufacture paper container 90 with a zipper, and Figure 2 shows a perspective view of paper container 90 with a zipper.

Unless otherwise specified, please refer to Figure 2, with the front wall panel 31b as the front side, and the front, back, left, right, top and bottom of the zippered paper container 90 are shown.

However, in the zippered paper container 90 described in Patent Document 1, when the top protrusion (ear) 74 is folded downward (towards the body) and joined to the body 72, damage (cracks) 82 may occur in the folded portion 76 of the top protrusion (ear) 74 that is located between the top protrusion (ear) 74 and the front top panel 33b and the front upper overlapping plate 34b (see Figures 3, 4, and 5).

This is because the upper part of the zippered paper container 90 is sealed by joining the inner surfaces of the upper stacking plates 34a and 34b together, so the number of layers in that part increases and the thickness increases.

Furthermore, zipper tape 61 is also attached to the upper overlapping plates 34a and 34b, so the number of layers in that part increases, and the thickness of that part becomes even thicker.

In addition, in Figures 4 and 5, the cross section of the blank plate 95 of the zippered paper container 90 is shown as a single layer, but the layer structure of the blank is a multi-layered laminate. However, in this specification, it is shown as a single layer to make the figures easier to see.

When the top protrusion (ear) 74 is strongly folded toward the body 72 (folded at a right angle), the outer surface of the folded portion 76 of the top protrusion (ear) 74, which is located between the top protrusion (ear) 74 and the front upper overlapping plate 34b and the front top plate 33b, becomes strongly stretched, which may cause damage (cracks) 82 in the laminated sheet 81 (reference number omitted in the figures) of the zippered paper container 90, as shown in Figures 4 and 5.

Note that the damage (cracks) shown in the figure are merely examples of damage, and the form of damage is not limited to these.

Figure 3 is a plan view of the zippered paper container 90, and explains the positions of the cross sections in Figures 4 and 5. Figure 4 is a horizontal cross section of the zippered paper container 90 near the center in the depth direction, with the upper stacking plates 34a and 34b folded down, and the cut surface is shown at the cross section position A-A in Figure 3. Figure 4 is also an enlarged view of the folded portion 76 of the top surface protrusion (ear) 74 in the horizontal cross section. A crack has occurred in the front upper stacking plate 34b, which is the outermost layer of the zippered paper container 90. Damage may also extend to the inner, back upper stacking plate 34a.

The explanation of the cross-sectional positions in Figure 3 is also used as a reference for explaining the cross-sections in the embodiments of the present invention.

Figure 5 is a cross-sectional view of the zipper tape 61 in the longitudinal direction at the position of the zipper tape 61 provided on the zipper-equipped paper container 90. Figure 5 is also an enlarged view of the folded portion 76 of the top surface protrusion (ear portion) 74, and the cut surface is shown at position B-B of the cross section shown in Figure 3. A crack has occurred in the front upper overlapping plate 34b, which is the outermost layer of the laminated sheet 81 of the zipper-equipped paper container 90.

The angle θ shown in Figures 4 and 5 indicates the angle between the front upper overlapping plate 34b constituting the top 71 of the zippered paper container 90 and the top protruding portion (ear) 74, and indicates the angle between the respective outer surfaces. Hereinafter, the angle θ described will have the same meaning.

Many of the laminated sheets 81 in the zippered paper containers 90 are made up of a paper base layer and a synthetic resin film layer, and among these components, the paper base layer, which has poor tensile strength, is prone to cracking. In particular, when the material is stretched too much, cracks may also appear in the inner synthetic resin film layer.

If cracks occur in the synthetic resin film layer, the barrier properties (oxygen, water vapor, etc.) of the laminated sheet 81 may be reduced. In particular, a reduction in barrier properties may be observed when the synthetic resin film layer itself has barrier properties or when the synthetic resin film layer is subjected to vapor deposition processing.

In addition, damage to the laminated sheet 81 can result in a loss of aesthetic appeal, and if the laminated sheet 81 is printed, the letters and images displayed by the printing can be damaged.

JP 2005-178833 A

The present invention has been made to solve the above problems, and its object is to provide a paper container 90 with a zipper that is less likely to suffer damage (cracks) in the folded portion 76 of the top protrusion (ear) 74, which is located between the top protrusion (ear) 74 and the front top panel 33b and the front upper overlapping plate 34b, when the top protrusion (ear) 74 is folded toward the body 72 of the paper container 90 and joined to the body 72.

The above problem can be solved by one embodiment of the present invention as follows.

That is, the zippered paper container 90 according to the embodiment of the present invention is
A paper container with a zipper 90 is formed by assembling a blank plate 95 made of a laminated sheet 81 having a paper base layer, and a side seal margin 36 is formed at the left and right edge portions of the blank plate 95 by a first vertical folding line 11,
The upper overlapping plates 34a, 34b, the top panels 33a, 33b, and the wall panels 31a, 31b are successively provided symmetrically above and below the intermediate horizontal folding line 21 of the blank plate 95 in the vertical direction, with the intermediate horizontal folding line 21 being the center.
The upper overlapping plates 34a, 34b and the top plates 33a, 33b are connected via first horizontal folding lines 22a, 22b that cross the blank plate 95 in the horizontal direction,
The top panels 33a, 33b and the wall panels 31a, 31b are connected via second horizontal folding lines 23a, 23b that cross the blank plate 95 in the horizontal direction,
The wall panels 31a and 31b are connected to the left and right sides of the wall panels 31a and 31b via a second vertical folding line 12 that runs vertically through the blank panel 95,
The upper overlapping plates 34a, 34b are provided with easy-open processing lines 51a, 51b and zipper tape joints 52a, 52b in sequence from the intermediate horizontal folding line 21 at positions where they will overlap each other when folded in half at the intermediate horizontal folding line 21.
When the sheet is folded in half at the intermediate horizontal folding line 21, the zipper tape 61 and the laminated sheet 81 are joined at the position where the zipper tape joints 52a and 52b are to overlap.
When the sheet is folded in half at the intermediate horizontal folding line 21, the side seal margins 36 on both sides that face each other are joined together.
The overlapped upper overlapping plates 34a, 34b are left, and the lower portions thereof are spread forward and backward along the horizontal folding lines 22a, 22b, so that a top portion 71 is formed below the upright overlapping upper overlapping plates 34a, 34b by the top panels 33a, 33b, and a body portion 72 having a rectangular cross section is connected to the lower portion of the top portion 71.
The upper overlapping plates 34a, 34b are folded back and laid down, and the top surface protruding portions (ears) 74 protruding on both the left and right sides are folded toward the body portion 72, and the top surface protruding portions (ears) 74 are joined to the body portion 72.
A bottom portion 73 connected to the lower portion of the body portion 72 is sealed.
A feature of this paper container is that the angle θ of the bent portion 76 that is generated when the top surface protrusions (ears) 74 connected to both the left and right sides of the top portion 71 of the paper container 90 with a zipper are joined to the body portion 72 of the paper container 90 with a zipper is an obtuse angle.

In addition, the paper container 90 with a zipper according to the embodiment of the present invention is
A paper container with a zipper 90 is formed by assembling a blank plate 95 made of a laminated sheet 81 having a paper base layer, and a side seal margin 36 is formed at the left and right edge portions of the blank plate 95 by a first vertical folding line 11,
The upper overlapping plates 34a, 34b, the top panels 33a, 33b, and the wall panels 31a, 31b are successively provided symmetrically above and below the intermediate horizontal folding line 21 of the blank plate 95 in the vertical direction, with the intermediate horizontal folding line 21 being the center.
The upper overlapping plates 34a, 34b and the top plates 33a, 33b are connected via first horizontal folding lines 22a, 22b that cross the blank plate 95 in the horizontal direction,
The top panels 33a, 33b and the wall panels 31a, 31b are connected via second horizontal folding lines 23a, 23b that cross the blank plate 95 in the horizontal direction,
The wall panels 31a and 31b are connected to the left and right sides of the wall panels 31a and 31b via a second vertical folding line 12 that runs vertically through the blank panel 95,
The upper overlapping plates 34a, 34b are provided with easy-open processing lines 51a, 51b and zipper tape joints 52a, 52b in sequence from the intermediate horizontal folding line 21 at positions where they will overlap each other when folded in half at the intermediate horizontal folding line 21.
When the sheet is folded in half at the intermediate horizontal folding line 21, the zipper tape 61 and the laminated sheet 81 are joined at the position where the zipper tape joints 52a and 52b are to overlap.
When the sheet is folded in half at the intermediate horizontal folding line 21, the side seal margins 36 on both sides that face each other are joined together.
The overlapped upper overlapping plates 34a, 34b are left, and the lower portions thereof are spread forward and backward along the horizontal folding lines 22a, 22b, so that a top portion 71 is formed below the upright overlapping upper overlapping plates 34a, 34b by the top panels 33a, 33b, and a body portion 72 having a rectangular cross section is connected to the lower portion of the top portion 71.
The upper overlapping plates 34a, 34b are folded back and laid down, and the top surface protruding portions (ears) 74 protruding on both the left and right sides are folded toward the body portion 72, and the top surface protruding portions (ears) 74 are joined to the body portion 72.
A bottom portion 73 connected to the lower portion of the body portion 72 is sealed.
A characteristic of this paper container is that the folding portion 76 that is generated when the top surface protrusions (ears) 74 connected to both the left and right sides of the top 71 of the paper container 90 with a zipper are joined to the body 72 of the paper container 90 with a zipper is bent in a curved line.

As described above, according to the embodiment of the present invention, the angle θ of the bent portion 76 of the top protrusion (ear) 74, which is connected to both the left and right sides of the top portion 71 of the chuck paper container 90, that is generated when the top protrusion (ear) 74 is joined to the body portion 72 of the chuck paper container 90 is an obtuse angle, so that the outer surface of the bent portion 76 of the top protrusion (ear) 74 is not strongly stretched, and damage (cracks) 82 to the bent portion 76 of the laminated sheet 81 of the chuck paper container 90 can be reduced.

In addition, according to one embodiment of the present invention, when the top protrusions (ears) 74 connected to both the left and right sides of the top 71 of the zippered paper container 90 are joined to the body 72 of the zippered paper container 90, the folded portions 76 of the top protrusions (ears) 74 are curved. This prevents the outer surface of the folded portion 76 of the top protrusions (ears) 74 from being strongly stretched, and prevents damage (cracks) 82 from occurring in the folded portions 76 of the laminated sheet 81 of the zippered paper container 90.

FIG. 2 is a development view of a blank plate used to manufacture the zippered paper container of the first embodiment of the present invention. FIG. 1 is a perspective view of a paper container with a zipper according to the prior art. FIG. 1 is a plan view of a paper container with a zipper according to the prior art. FIG. 3 is an enlarged cross-sectional view of a folded portion of a protruding portion (ear) on a top surface of a paper container with a zipper according to the prior art (see cross section A-A in FIG. 3). FIG. 3 is an enlarged cross-sectional view of a folded portion at a zipper tape joining position of a top protrusion (ear) of a zipper-equipped paper container of the prior art (see cross section B-B in FIG. 3). 2 is a front view showing the shape of a paper container with a zipper at an intermediate stage when the paper container is produced using the blank plate shown in FIG. 1 . FIG. 2 is a perspective view showing the shape of a paper container at an intermediate stage when a paper container with a zipper is produced using the blank plate shown in FIG. 1 . FIG. FIG. 1 is a perspective view of a zippered paper container according to a first embodiment of the present invention. FIG. 1 is a front view of a zippered paper container according to a first embodiment of the present invention. Fig. 3 is an enlarged cross-sectional view of a folded portion of a protruding portion (ear portion) on a top surface side of a zipper-equipped paper container according to a first embodiment of the present invention (see cross section A-A in Fig. 3). FIG. 11 is a front view of a zippered paper container according to a second embodiment of the present invention. Fig. 3 is an enlarged cross-sectional view of a folded portion of a top surface protruding portion (ear portion) of a zipper-equipped paper container according to a second embodiment of the present invention (see cross section A-A in Fig. 3).

The present invention will be described below with reference to the drawings. However, the present invention is not limited to these specifically shown forms or the various specifically described structures.

In addition, in each figure, the size and proportions of components may be changed or exaggerated to make them easier to understand. Also, for ease of viewing, parts that are not necessary for the explanation or repeated symbols may be omitted.

Figure 1 shows a blank plate 95 of a zippered paper container 90 according to a first embodiment of the present invention. The blank plate 95 according to the first embodiment of the present invention has the same shape as the blank plate 95 of the prior art described above.

Unless otherwise specified, the top, bottom, left and right of the blank plate 95 will be indicated with reference to Figure 1. Also, the front surface of Figure 1 is our outer surface when the zippered paper container 90 is assembled, and the back surface is our inner surface.

The blank plate 95 of the paper container with a zipper 90 of the present invention is formed into a rectangular shape using a laminated sheet 81 in which a base paper is laminated at least in the middle layer and a heat-adhesive resin such as polyethylene is laminated at least in the innermost layer, and the blank plate 95 is provided with a first vertical fold line 11 and a second vertical fold line 12 in the longitudinal direction, a middle horizontal fold line 21 in the transverse direction, first horizontal fold lines 22a, 22b, second horizontal fold lines 23a, 23b, third horizontal fold lines 24a, 24b, and fourth horizontal fold lines 25a, 25b, diagonal fold lines 13a, 13b on the top surface, and diagonal fold lines 14a, 14b on the bottom surface, and is configured to divide the forming plates for each part required to form the paper container with a zipper 90.

That is, at the left and right edges of the blank plate 95, the side seal margins 36 are formed by the first vertical fold line 11, and at the top and bottom edges, the back side bottom seal margins 37a are formed by the back side fourth horizontal fold line 25a, and the front side bottom seal margins 37b are formed by the front side fourth horizontal fold line 25b.

The blank plate 95 has forming plates arranged symmetrically above and below the intermediate horizontal fold line (half fold line) 21. The main parts are arranged in the following order above the intermediate horizontal fold line (half fold line) 21: the rear upper overlapping plate 34a, the rear top panel 33a, the rear wall panel 31a, and the rear bottom panel 35a.

Below the intermediate horizontal fold line (half fold line) 21, the blank plate 95 is connected in this order to the front upper overlapping plate 34b, the front top panel 33b, the front wall panel 31b, and the front bottom panel 35b.

Furthermore, rear side panels 32a are connected to the left and right of rear wall panel 31a, and front side panels 32b are connected to the left and right of front wall panel 31b. Furthermore, when blank plate 95 is folded in half at intermediate horizontal fold line (half fold line) 21, easy-to-open processing lines 51a, 51b as horizontal opening means and zipper tape joints 52a, 52b are provided in sequence on both sides of upper overlapping panels 34a, 34b, in a position where they overlap each other on both sides.

It is also desirable that the easy-open processing lines 51a, 51b and the zipper tape joints 52a, 52b are approximately parallel to the intermediate horizontal fold line (half fold line) 21.

When the easy-open processing lines 51a, 51b are approximately parallel to the intermediate horizontal fold line (half fold line) 21, the zippered paper container 90 can be easily cut horizontally.

When the zipper tape joints 52a, 52b are approximately parallel to the intermediate horizontal fold line (half fold line) 21, it is easy to open and close the zipper and remove the contents.

In this case, the zipper tape joints 52a and 52b are the planned joints of the zipper tape 61. The actual joining of the zipper tape 61 is performed by half-folding the blank plate 95 at the intermediate horizontal fold line (half-fold line) 21 and heat-sealing the side seal margins 36 together, inserting the zipper tape 61, which has already been fitted at the fitting portion between the male tape body 64 and the female tape body 65, into this portion, and at the same time, heating and pressurizing the zipper tape joints 52a and 52b from the outer surface of the blank plate 95 to thermally bond them.

The method of joining the zipper tape 61 is not limited to heat sealing as described above, but may also use adhesive or adhesive tape, or may be mechanically fitted.

Here, the outer surface of the blank plate 95 refers to the surface of the blank plate 95 that is to become the outer surface of the chuck-equipped paper container 90 when the chuck-equipped paper container 90 is assembled.

By heat-bonding the zipper tape 61 in this manner, there is no misalignment in the heat bonding compared to a method in which the male tape body 64 and the female tape body 65 are separately heat-bonded to the zipper tape joints 52a, 52b, and the attachment process is simplified, so the zipper tape 61 can be attached with high production efficiency.

The intermediate horizontal fold line (half fold line) 21 provided for folding the blank plate 95 in half may be a normal pressed fold line, but since easy-to-open processing lines 51a, 51b are provided on both sides of the intermediate horizontal fold line (half fold line) 21 as opening means, it is preferable that the fold line be one that is easier to fold so as not to break the easy-to-open processing lines 51a, 51b (e.g. perforation lines, half-cut lines, etc.) when folding the blank plate 95 in half during the manufacturing process. For this reason, it is even more preferable to use a fold line with a long cut line portion and with creasing applied to the connecting parts, such as a fold line called a lead crease. This cut line may also be a half-cut cut line.

By making the intermediate horizontal fold line (half fold line) 21 into such a fold line, when folding the blank plate 95 in half, it is not folded accidentally at the easy-to-open processing lines 51a, 51b of the opening means, and it can be folded in half easily and reliably at the intermediate horizontal fold line (half fold line) 21, which eliminates the occurrence of defective products due to improper folding position, and enables folding at high speed, improving production efficiency.

The intermediate horizontal fold line (half fold line) 21 may be processed into the laminated sheet 81 after lamination in the same way as other fold lines, but processing a deeper fold line (crease processing) may result in holes being generated in the laminated sheet 81.

However, by providing the intermediate horizontal fold line (half fold line) 21 in the paper base layer before lamination, similar to the easy-open processing lines 51a, 51b of the opening means, and laminating polyethylene or the like on both sides of the fold line, it is possible to prevent a decrease in the sealing ability of the zippered paper container 90.

When the intermediate horizontal fold line (half fold line) 21 is processed into the laminated sheet 81 after lamination, after the blank plate 95 is half-folded, the upper overlapping plates 34a, 34b are heat-sealed, for example, in the area from the folded portion of the intermediate horizontal fold line (half fold line) 21 or its vicinity to the vicinity of the upper side of the zippered paper container 90 of the overlapping easy-to-open processing lines 51a, 51b (perforation lines in this embodiment) on both sides. This maintains the airtightness of the zippered paper container 90 and also allows the easy-to-open processing lines 51a, 51b on both sides of the upper overlapping plates 34a, 34b to be brought closer to each other, making it easier to cut off the easy-to-open processing lines 51a, 51b when opening.

When using intermittent half-cut lines or straight half-cut lines for the easy-open processing lines 51a, 51b of the opening means or the intermediate horizontal fold line (half-fold line) 21 for half-folding, they may be formed using a normal blade method, but half-cut lines can be formed with greater precision and stability by using a method that uses laser light irradiation, a method that uses ultrasonic waves, or a method known as diamond cutting.

The laminated sheet 81 used for the blank plate 95 is, as described above, a laminated sheet 81 in which at least a paper base layer is laminated as an intermediate layer, and a heat-adhesive resin such as polyethylene is laminated on both sides as an innermost layer or an outermost layer, but the intermediate layer can be provided with a water vapor, oxygen or other gas barrier layer, a strength improving layer, etc., as necessary.

When providing a printed layer such as a pattern on the zipper-equipped paper container 90, the pattern is usually printed on the surface of the paper base layer. However, if the paper base layer does not have good printability, a printed layer such as a pattern can be provided on a biaxially oriented polyethylene terephthalate film, which also serves as a strength improving layer, and the film can be laminated between the outermost heat-adhesive resin layer and the paper base layer.

The paper base layer is preferably a paper that is rigid and does not easily crack when folded along a folding line, but there are no particular limitations and a suitable paper can be selected and used depending on the contents to be filled into the zippered paper container 90, taking into consideration water resistance (size degree) and other factors.

As specific examples, wood-free paper, bleached kraft paper, cup base paper, milk carton base paper, etc. can be suitably used, and the appropriate basis weight is in the range of 90 to 320 g/ ^m2 .

The resin for the innermost or outermost heat-adhesive resin layer (sealant layer) can be selected from low-density polyethylene (LDPE), linear low-density polyethylene (LLDPE), medium-density polyethylene (MDPE), high-density polyethylene (HDPE), ethylene-α-olefin copolymer polymerized using a single-site catalyst, ethylene-vinyl acetate copolymer (EVA), ethylene-acrylic acid copolymer (EAA), ethylene-methacrylic acid random copolymer (EMAA), ethylene-methyl acrylate copolymer (EMA), ethylene-ethyl acrylate copolymer (EEA), ionomer, polypropylene and its copolymers, polyester resins, etc., and the appropriate one can be selected from these depending on the contents to be filled and the conditions of storage and use.

Among the above heat-adhesive resins, ethylene-methyl acrylate copolymer (EMA) and ethylene-methacrylic acid random copolymer (EMAA) are particularly excellent in terms of thermal stability during processing such as extrusion coating, adhesion to various substrates, low-temperature heat sealability, and thin-film formability. Therefore, it is easy to extrude and laminate the outermost heat-adhesive resin layer, which does not require a large thickness, at a relatively thin thickness of, for example, 6 to 10 μm, and this allows the proportion of plastic material used to be reduced while also providing cost benefits.

The innermost or outermost heat-adhesive resin layer as described above can be laminated by extrusion coating the resin on the laminated surface after performing an easy-adhesion treatment such as anchor coating, corona treatment, or flame (flame) treatment as necessary, or the heat-adhesive resin can be formed into a film in advance and laminated by bonding the film using a known dry laminate or extrusion laminate (sandwich laminate) method.

When a gas barrier layer is laminated on the intermediate layer of the laminated sheet 81, the gas barrier layer can be a metal foil such as aluminum foil, or a vapor-deposited film in which a metal or inorganic oxide such as aluminum, silica, or alumina is vapor-deposited to a thickness of 20 to 100 nm on a base film such as a biaxially oriented polyethylene terephthalate film (hereinafter, PET film), a biaxially oriented nylon film (hereinafter, ON film), or a biaxially oriented polypropylene film (hereinafter, OPP film). Alternatively, a saponified ethylene-vinyl acetate copolymer film (hereinafter, EVOH film), a biaxially oriented nylon MXD6 film, a polyacrylonitrile film, or a PET film, ON film, or OPP film with a coating layer of polyvinylidene chloride can be used.

Normally, such a gas barrier layer is preferably laminated on the inner surface of the intermediate paper base layer, since the gas barrier properties can be effectively utilized; however, if a metal foil such as aluminum or a metal-deposited film is used for the gas barrier layer, the metallic look can also be utilized in the design, so that the gas barrier layer can be laminated on the outer surface of the paper base layer. The gas barrier layer can be easily laminated by known methods such as dry lamination or extrusion lamination (sandwich lamination).

In addition, when a peelable weak seal portion is provided on both or either of the upper and lower sides of the zipper tape 61, although this is not shown in the figure, when the blank plate 95 is folded in half at the intermediate horizontal folding line (half folding line) 21, the upper overlapping plates 34a and 34b that are in contact with each other are in an area excluding the side seal margins 36 on both sides, and when a weak seal portion is provided on the lower side of the zipper tape 61, for example, both or either of the surfaces of the space between the back zipper tape joint 52a and the back first horizontal folding line 22a and the space between the front zipper tape joint 52b and the front first horizontal folding line 22b can be formed by applying a coating liquid of an easy-peel heat adhesive resin or a resin called an anti-heat sealant in a pattern along the zipper tape joints 52a and 52b by means of gravure printing or flexo printing, drying the coating liquid, and then heat sealing the portion.

It is preferable that the peelable weak seal portion has a sealability and can be peeled off with a moderate force, and the heat seal strength is preferably in the range of 1 to 16 N/15 mm width.

When the weak seal portion is formed from an easy-peel heat-adhesive resin, the easy-peel heat-adhesive resin may be, for example, a resin composition in which a polyolefin resin such as low-density polyethylene or ethylene-vinyl acetate copolymer is appropriately mixed with additives such as polystyrene, chlorinated polypropylene, polybutene-1, inorganic or organic fillers, polyethylene wax, or fatty acid amides.

As for the inorganic or organic filler, powders of silica, calcium carbonate, talc, kaolin, clay, titanium oxide, alumina, aluminum hydroxide, etc. can be used as inorganic fillers, and silica powder is particularly preferred. As organic fillers, powders of melamine resin, urea resin, alkyd resin, epoxy resin, acrylic resin, polystyrene, ethylene fluoride resin, silicone resin, etc. can be used.

The content of the additive in the resin composition is preferably in the range of 4 to 40% by mass. If the content of the additive is less than 4% by mass, the heat seal strength will be too strong and good weak seals (easy peel properties) will not be obtained. If the content of the additive exceeds 40% by mass, the heat seal strength will be too weak, which is not preferable.

The coating amount of the above-mentioned easy-peel thermal adhesive resin is preferably 2 to 8 g/m ² , more preferably 3 to 5 g/m ² when dried.

When the weak seal portion is formed with a heat-sealing agent, the heat-sealing agent may be a resin composition in which an appropriate amount of a release agent is mixed with the base resin.

For example, ethyl cellulose, cyclized rubber, acrylic resin, etc. can be used as the resin for the base material, and for example, silicone resin, polyethylene wax, soybean lecithin, higher fatty acid amide, etc. can be used as the release agent. When applying an anti-heat seal agent, the amount of application can be small, and a thickness in the range of 0.3 to 2 μm is appropriate.

The blank plate 95 is scored after the laminated sheet 81 is completed, and then the laminated sheet 81 is fed to a machine that manufactures the chuck-equipped paper container 90. Alternatively, the scoring may be performed by the machine that manufactures the chuck-equipped paper container 90.

The appropriate method for creasing can be selected from known methods such as the platen method and the rotary die method.

The laminated sheet 81 may be cut into sheets before the creasing process is performed. Alternatively, the laminated sheet 81 may be supplied to the creasing process in a roll form.

The punching process for punching the laminated sheet 81 to manufacture the blank plate 95 will now be described. For the punching process, an appropriate method is selected from known methods such as a platen method and a rotary die method. The blank plate 95 may be formed directly from the rolled laminated sheet 81, or the sheet may be cut into individual sheets and then punched.

The order of the creasing and punching processes does not matter. They may be performed simultaneously.

Alternatively, the rolled laminated sheet 81 slit to a predetermined roll width may be fed to a machine for manufacturing paper containers 90 with zippers, and the rolled laminated sheet may be cut in the transverse direction to produce the blank plate 95.

Figure 6 is a front view showing the shape of a zippered paper container (flat state) 91 at an intermediate stage (flat state) when manufacturing a zippered paper container 90 using the blank plate 95 shown in Figure 1. The top part is formed by folding the blank plate 95 in half at the intermediate horizontal folding line (half folding line) 21 shown in Figure 1, and when folding in half, the zipper tape 61, which has a male tape body 64 and a female tape body 65 previously fitted together, is inserted at the position where the zipper tape joints 52a, 52b overlap, and the zipper tape joints 52a, 52b are heat-bonded by heating and pressurizing the outer surface of the blank plate 95.

Next, the side seal margins 36 of the left and right edge portions are heat sealed together to form a bag-like shape with an opening at the bottom. Also, notches 77 are provided at both ends of the easy-open processing lines 51a, 51b that overlap above the zipper tape joints 52a, 52b. The notches 77 may be provided at either end.

In addition, when a crushed portion is provided at the folded portion of the zipper tape 61 to facilitate folding, although this is not shown in the figure, the zipper tape 61 thermally bonded to the zipper tape joints 52a and 52b can be pressed against the outer surface of the laminated sheet 81 of the zippered paper container 90 with a heat press or the like to crush the zipper tape 61 to a size of about 2 mm at a position perpendicular to the second vertical folding line 12, thereby forming the crushed portion.

The zippered paper container 90 is not particularly limited in the actual manufacturing process, but in order to improve productivity, a device that manufactures paper containers, fills them with the contents, and seals each joint in-line can be used to pay out a long printed laminated sheet 81 wound up in a roll, and the paper containers can be connected horizontally to process the folding lines, fold in half, insert and heat-seal the zipper tape 61, heat-seal the side seal margins 36, punch out the notches 77, etc.

However, the order of the steps may be different from that described above as long as the desired paper container 90 with a zipper is obtained.

Next, the intermediate stage paper container with zipper (flat state) 91 shown in FIG. 6 is manufactured by cutting into individual paper containers, and then the paper container is raised into a three-dimensional shape. The upper overlapping plates 34a, 34b are folded toward the back side, and the top side protrusions (ears) 74 on both sides are joined to the body 72 of the paper container, and the bottom of the paper container that opens is placed up, and the contents are filled from the bottom that opens. After that, the bottom side seal margins 37a, 37b are heat sealed and folded, and then the bottom side protrusions (ears) 75 protruding on both sides of the bottom 73 of the paper container with zipper 90 are folded and heat bonded to the bottom plates 35a, 35b, and the package of the paper container with zipper 90 can be completed.

Figure 8 is a perspective view showing a first embodiment of a zippered paper container 90 of the present invention.

The zippered paper container 90 shown in FIG. 8 has a rectangular parallelepiped outer shape, and such a zippered paper container 90 can be made by the following procedure.

For example, a blank plate 95 having the configuration shown in FIG. 1 is folded in half at the intermediate horizontal folding line (half folding line) 21 as shown in FIG. 6, and a zipper tape 61 having a male tape body 64 and a female tape body 65 previously fitted together is inserted at the position where the zipper tape joints 52a, 52b overlap, and the zipper tape joints 52a, 52b are thermally bonded by heating and pressurizing the outer side of the blank plate 95.

Next, the opposing side seals 36 are heat sealed, and notches 77 are provided at both ends of the overlapping easy-open processing lines 51a, 51b at the front and back to create a folded intermediate-stage zippered paper container (flat state) 91 with the bottom seals 37a, 37b open and unsealed.

Next, a mandrel is inserted through the opening of the bottom 73 of this intermediate-stage paper container with a zipper (flat state) 91, and the lower part is spread forward and backward along the folding line, leaving the upper overlapping plates 34a, 34b, so that the upper overlapping plates 34a, 34b stand upright, and below that is a flat top 71 made of the top plates 33a, 33b, followed by a body 72 with a rectangular cross section, and an intermediate-stage paper container with a zipper (raised box state) 92 with a rectangular opening at the bottom.

At this stage, the upper overlapping plates 34a and 34b are standing upright as shown in Figure 7.

Next, the upper overlapping plates 34a, 34b that stand upward are folded toward the back side (toward the back top panel 33a) and laid down, and the top protruding parts (ears) 74 that protrude on both the left and right sides are folded toward the side panels 32a, 32b and joined by thermal bonding or the like.

Methods for joining include using adhesive (hot melt, etc.), using adhesive tape, and mechanical joining (engaging, using a joining tool). Also, if there is a thermoplastic resin layer (sealant layer) on the outermost surface of the blank plate 95, there is a method of heat sealing the thermoplastic resin layer.

In addition, the tip of the top surface protrusion (ear) 74 may be joined to the body 72 of the zippered paper container 90.

In addition, a portion of the top protrusion (ear) 74 other than the tip may be joined to the body 72 of the zippered paper container 90. In that case, the tip of the top protrusion (ear) 74 does not need to be joined to the body 72 of the zippered paper container 90.

As mentioned above, the technical innovations involved in this embodiment in the process of bending the top projections (ears) 74 and joining them to the side panels 32a and 32b will be explained later.

The bottom of the paper container formed as described above is turned up, and the contents are filled in through the open bottom. The bottom is then folded and the bottom seal margins 37a, 37b are heat sealed together using a palm-to-palm seal method. The bottom seal margins 37a, 37b are then folded, for example, toward the back side (toward the bottom plate 35a) and laid down, and the bottom protruding parts (ears) 75 protruding on both the left and right sides are folded toward the bottom plates 35a, 35b and joined, completing the packaging of the rectangular shaped paper container 90 with a zipper.

In the configuration of the zippered paper container 90 shown in FIG. 8, the upper back overlapping plate 34a has an easy-to-open back processing line 51a, and the zipper tape 61 is heat-bonded to the inner surface of the bottom side of the easy-to-open processing lines 51a and 51b of the upper overlapping plates 34a and 34b, as described above, but these are not shown because they are in positions that cannot be seen from the outside.

In the first embodiment of the zippered paper container 90, the bending angle θ of the bent portion 76 of the top protrusion (ear) 74, which is interposed between the top protrusion (ear) 74 and the front top panel 33b and the front upper overlapping plate 34b, is an obtuse angle (see Figs. 9 and 10). Fig. 10 is an enlarged cross-sectional view of the bent portion 76 of the top protrusion (ear) 74 in Fig. 9.

In the zippered paper container 90 of this embodiment, the amount (length) of stretching of the outer surface of the folded portion 76 of the top protrusion (ear) 74 is less than when the folding angle θ of the folded portion 76 of the top protrusion (ear) 74 is approximately a right angle, so damage (cracks) to that portion is less likely to occur.

To make the bending angle θ of the bent portion 76 of the top surface protrusion (ear) 74 an obtuse angle and to join the top surface protrusion (ear) 74 to the body 72, the tip of the top surface protrusion (ear) 74 is bent toward the body 72. This process can be performed by clamping the top surface protrusion (ear) 74 with metal fittings, and may be performed before or simultaneously with bending the top surface protrusion (ear) 74.

In the second embodiment of the zippered paper container 90, it is desirable to set the bending angle θ of the bending portion 76 of the top surface protrusion (ear portion) 74 to 100° or more and 160° or less.

If the bending angle θ of the bent portion 76 of the top protrusion (ear) 74 is less than 100°, damage (cracks) are likely to occur on the outer surface of the bent portion 76 of the top protrusion (ear) 74, and if the bending angle θ of the bent portion 76 of the top protrusion (ear) 74 exceeds 160°, it becomes difficult to join the top protrusion (ear) 74 to the body 72.

Furthermore, because the protruding portion (ear) 74 on the top surface protrudes to a greater extent, there is a risk that it may come into contact with an obstacle during use or transportation, and as a result, the protruding portion (ear) 74 on the top surface may easily come off the body portion 72.

It is even more desirable to set the bending angle θ of the bent portion 76 of the top surface protrusion (ear portion) 74 to 120° or more and 150° or less.

In the third embodiment of the zippered paper container 90, the bend 76 of the top protrusion (ear) 74, which is between the top protrusion (ear) 74 and the front top panel 33b and the front upper overlapping plate 34b, is curved (see Figures 11 and 12).

Figure 12 is an enlarged cross-sectional view of the bent portion 76 of the top surface protrusion (ear portion) 74 in Figure 11.

In the zippered paper container 90 of this embodiment, the amount (length) that the outer surface of the folded portion 76 of the top protrusion (ear) 74 is stretched is smaller than when the folded portion 76 of the top protrusion (ear) 74 has an angle rather than a curve (when the radius of curvature is extremely small), so damage (cracks) to that portion is less likely to occur.

To make the bent portion 76 of the top surface protrusion (ear) 74 curved and to join the top surface protrusion (ear) 74 to the body 72, the tip of the top surface protrusion (ear) 74 is bent toward the body 72. This process can be performed by clamping the top surface protrusion (ear) 74 with metal fittings, and may be performed before or at the same time as bending the top surface protrusion (ear) 74.

In the fourth embodiment of the zippered paper container 90, the radius of curvature R of the folded portion 76 of the top surface protrusion (ear portion) 74 is 1 mm or more and 10 mm or less.

If the radius of curvature of the bent portion 76 of the protruding portion (ear) 74 on the top surface is less than 1 mm, damage (cracks) will easily occur on the outer surface of the bent portion, and if the radius of curvature of the bent portion exceeds 10 mm, it will be difficult to join the protruding portion (ear) 74 on the top surface to the body portion 72.

Furthermore, because the protruding portion (ear) 74 on the top surface protrudes to a greater extent, there is a risk that it may come into contact with an obstacle during use or transportation, and therefore the protruding portion (ear) 74 on the top surface may become easily detached.

The zippered paper container 90 of the fifth embodiment is formed from the blank plate 95, and in the blank plate 95, the wall plates 31a, 31b and the bottom plates 35a, 35b are connected via third horizontal fold lines 24a, 24b that cross the blank plate 95 in the horizontal direction, and the bottom plates 35a, 35b and the bottom side seal margins 37a, 37b that are the upper and lower edge portions of the blank plate 95 are connected to each other in the horizontal direction of the blank plate 95. The bottom seal margin 37a on the back side and the bottom seal margin 37b on the front side are joined in a palm-to-palm seal format via the fourth horizontal fold lines 25a and 25b that cross each other, and the joined bottom seal margins 37a and 37b are folded toward the back side and laid down, and the bottom protrusions (ears) 75 that protrude from both the left and right sides of the bottom 73 of the zippered paper container 90 are folded toward the bottom panels 35a and 35b and joined.

The zippered paper container 90 of this embodiment can form a stable bottom after filling the contents inside, providing a zippered paper container 90 with reduced leakage of the contents.

In addition, since no separate parts are used to form and seal the bottom, it is low cost.

In the manufacturing method of the paper container with a zipper 90 of the sixth embodiment, the wall panels 31a, 31b and the bottom panels 35a, 35b are connected via third horizontal folding lines 24a, 24b that cross the blank panel 95 in the horizontal direction, the bottom panels 35a, 35b and the bottom side seal margins 37a, 37b that are the left and right edge portions of the blank panel 95 are connected via fourth horizontal folding lines 25a, 25b that cross the blank panel 95 in the horizontal direction, and the bottom side seal margins 37a, 37b are not yet This manufacturing method includes a process of forming an intermediate folded shape that opens with a seal, filling the contents through the open bottom 73, joining the back side bottom seal margin 37a and the front side bottom seal margin 37b in a palm-to-palm seal format, folding the joined bottom seal margins 37a and 37b back and laying them down, and folding the bottom protruding parts (ears) 75 that protrude from both the left and right sides of the bottom 73 of the zippered paper container 90 toward the bottom panels 35a and 35b to join them.

In the manufacturing method of the paper container 90 with a zip fastener of this embodiment, the procedures for manufacturing the paper container, filling the contents, and sealing the container are appropriate, so that the paper container 90 with a zip fastener, which is used for filling and sealing the contents, can be manufactured using a rational manufacturing device, thereby reducing costs.

The following examples further illustrate the present invention.

Example 1
In Example 1, a blank plate 95 having the configuration shown in Figure 1 was used to produce a paper container with a zipper 90 having the configuration shown in Figure 8. An intermediate stage paper container with a zipper (standing state) 92 with an open bottom 73 was produced as described below, and then the paper container with a zipper 90 of Example 1 was produced.

The laminated sheet 81 of the blank plate 95 was made of the following laminated sheet 81:

(Outer surface) Printed layer with patterns, etc. (gravure printing) /
LDPE layer (thickness 20 μm) (Japan Polyethylene, LC520) /
Paper base layer (Nippon Paper Industries, base paper for liquid paper containers) (150 g/m ² ) /
EMAA (20 μm) (Mitsui Dow Polychemical, N0908N) /
Silica-deposited PET (12 μm) (Dai Nippon Printing, IB-PET-UBP) /
LDPE layer (40 μm) (Japan Polyethylene, LC520) (inner surface)
A method for producing the laminated sheet 81 will now be described.

First, an LDPE layer (20 μm) is formed on the outer surface of the paper base layer by extrusion lamination.

Next, silica-deposited PET (12 μm) is laminated to the inner surface of the paper base layer by extrusion lamination (sandwich lamination) with molten EMAA (20 μm) in between.

Next, an LDPE layer (40 μm) is formed by extrusion lamination on the opposite side (inner surface) of the paper base layer of the silica-deposited PET (12 μm).

Next, a pattern or the like is printed on the outer surface of the LDPE layer (20 μm) formed on the outer surface of the paper base layer using a gravure printer.

After printing on the paper base layer, an LDPE layer (20 μm) may be formed on the outer surface of the paper base layer by extrusion lamination, or, after printing on the paper base layer, extrusion lamination on the outer surface may not be performed.

In addition, to improve the bonding strength between each bonding layer, anchor coat treatment, corona treatment, flame treatment, etc. may be performed as necessary. Alternatively, ozone treatment may be performed on the molten resin.

By following the above procedure, the laminated sheet 81 of the blank plate 95 is manufactured.

Next, the laminated sheet 81 is subjected to scoring and punching to complete the blank plate 95. The scoring and punching can be performed in any order. They can also be performed simultaneously.

The zipper tape 61, which is attached by thermal bonding to the inner surface of the upper overlapping plates 34a, 34b of the paper container, has a two-layer laminated structure for both the male tape body 64 and the female tape body 65, with the resin layer on the side that is thermally bonded to the paper container being made of LLDPE and the resin layer on the opposite side being made of MDPE, and both the male and female mating parts being made of LLDPE, with the tape body width being 13 mm.

The dimensions of the blank plate 95 are a rectangle with a length of 440 mm and a width of 169 mm, with side seal margins 36 of 7 mm provided on the left and right edges, and bottom seal margins 37a, 37b of 10 mm provided on the top and bottom edges.

On the inside of the blank plate 95, the upper overlapping plates 34a, 34b, the top panels 33a, 33b, the wall panels 31a, 31b, and the side panels 32a, 32b and the bottom panels 35a, 35b are connected symmetrically above and below the intermediate horizontal fold line (half fold line) 21, in that order, via their respective fold lines, so that the dimensions of the completed rectangular parallelepiped paper container are 95 mm wide, 120 mm high, and 60 mm deep.

The upper overlapping plates 34a and 34b each have a length of 28 mm in the vertical direction (the lengthwise direction of the blank plate 95), and are sized so that when laid back on top of the rear top panel 33a during the formation of the paper container, their leading ends are 2 mm inward from the end of the rear top panel 33a.

The upper overlapping plates 34a, 34b are provided with easy-to-open processing lines (perforation lines) 51a, 51b printed on the paper base layer of the laminated sheet 81 in the horizontal direction at a position 6 mm below the intermediate horizontal fold line (half-fold line) 21, which becomes the upper end when the blank plate 95 is folded in half at the intermediate horizontal fold line (half-fold line) 21, as a means for easily opening the container. The zipper tape (width 13 mm) is thermally bonded to the inner surface of the upper overlapping plates 34a, 34b with a gap of 5 mm below the easy-to-open processing lines (perforation lines) 51a, 51b.

Furthermore, after the blank plate 95 was folded in half, the zipper tape was thermally bonded, and the side seal portion 36 was heat sealed using the method described above, notches 77 (see FIG. 6) were provided on both ends of the overlapping easy-to-open processing lines (perforation lines) 51a, 51b, and a zippered paper container (flat state) 91 in the intermediate stage where the bottom 73 is open was produced.

Next, a mandrel was inserted through the unsealed opening of the bottom 73 of this intermediate-stage paper container with a zipper (flat state) 91, and the lower part was spread forward and backward along the folding line, leaving the upper overlapping plates 34a, 34b, so that the upper overlapping plates 34a, 34b stood upright, and below that was a flat top 71 made up of the top plates 33a, 33b, followed by a body 72 with a rectangular cross section, and an intermediate-stage paper container with a zipper (raised box state) 92 with a rectangular opening at the bottom. (See Figure 7.)

By folding the overlapping upper overlapping plates 34a, 34b toward the back top plate 33a, a paper container with zipper tape was produced in which the top protrusions (ears) 74 connected to both the left and right sides of the top 71 of the zippered paper container 90 are joined to the body 72 of the paper container at three different angles, 100°, 135°, and 160°, between the top 71 and the top protrusions (ears) 74 via the folded portions 76 of the top protrusions (ears) 74.

The tip of the top protrusion (ear) 74 is folded inward of the zippered paper container 90 (downward before folding the top protrusion (ear) 74), making it easier to join the top protrusion (ear) 74 and the body 72.

Example 2
Using the same blank plate 95 as in Example 1, a paper container 90 with a zipper was produced.

By folding the overlapping upper overlapping plates 34a, 34b toward the back top plate 33a, the top protrusions (ears) 74 connected to both the left and right sides of the top 71 of the zippered paper container 90 are joined to the body 72 of the paper container, and when this is done, the portion extending from the top 71 to the top protrusions (ears) 74 via the folded portion 76 of the top protrusions (ears) 74 is curved, and a paper container with zipper tape is produced with three different radii of curvature R of approximately 2 mm, 5 mm, and 10 mm.

Other aspects such as shape, material, and processing method are the same as those in the first embodiment.
Comparative Example
In the comparative example, a paper container 90 with a zipper having the configuration shown in FIG. 2 was produced using a blank plate 95 having the configuration shown in FIG.

The overlapping upper overlapping plates 34a, 34b are folded toward the rear top panel 33a, so that when the top protrusions (ears) 74 connected to both the left and right sides of the top 71 of the zippered paper container 90 are joined to the body 72 of the paper container, the angle formed between the top 71 and the top protrusions (ears) 74 via the folded portions 76 of the top protrusions (ears) 74 is approximately a right angle.

Other aspects such as shape, material, and processing method are the same as in Example 1.

Evaluation
In the comparative example, damage (cracks) occurred in the laminated sheet 81 at the folded portion 76 of the protruding portion (ear portion) 74 on the top surface of the paper container 90 with a zipper.

In both Examples 1 and 2, no damage (cracks) occurred in the laminated sheet 81 at the folded portion 76 of the protruding portion (ear portion) 74 on the top surface of the zippered paper container 90.

The zippered paper containers 90 of Examples 1 and 2 prepared as described above were filled with snacks as the contents from the bottom 73, and then the bottom 73 was folded in and the bottom side seal margins 37a and 37b were heat sealed, and the heat sealed portion was laid down toward the back side bottom plate 35a. Furthermore, the bottom side protruding portions (ears) 75 protruding from both the left and right sides of the bottom 73 were folded toward the bottom plates 35a and 35b, and heat bonded to the front side bottom plate 35b and the front side bottom side seal margin 37b, completing the rectangular zippered paper container packages of Examples 1 and 2.

The rectangular shaped paper container packages with zippers of Examples 1 and 2 produced as described above were tested, particularly for their ease of opening, suitability for removing the contents, and resealability with the zipper. In all cases, the notches 77 provided as opening means at the top of the upper overlapping plates 34a and 34b and the easy-to-open processing lines (perforation lines) 51a and 51b allowed the packages to be easily opened by cutting off the upper part above the easy-to-open processing lines (perforation lines) 51a and 51b.

Next, by pinching the upper ends of the opened upper overlapping plates 34a, 34b and pulling them apart, the zipper engagement can be easily released, opening the top of the paper container across almost its entire width, and the snacks filled inside can be easily removed.

In addition, after removing a portion of the contents, the zippers of both the paper container packages with zippers in Examples 1 and 2 could be easily reattached to reseal the paper container, allowing the remaining contents to be properly preserved.

Furthermore, in the paper container with zipper of this embodiment, the mass ratio of paper to the mass of the entire paper container is approximately 60% by mass, which is fully in line with the standard of 51% by mass or more for paper containers.

11 First vertical fold line 12 Second vertical fold line 13a Diagonal fold line on the top surface of the back side 13b Diagonal fold line on the top surface of the front side 14a Diagonal fold line on the bottom surface of the back side 14b Diagonal fold line on the bottom surface of the back side 21 Middle horizontal fold line (half fold line)
22a Back first horizontal fold line (lower side of upper overlapping plate)
22b First horizontal fold line on the front side (lower side of the upper overlapping plate)
23a Second horizontal fold line on the back side (bottom of the top panel)
23b Second horizontal fold line on the front side (bottom side of the top panel)
24a Third horizontal fold line on the back side (bottom side of wall panel)
24b Third horizontal bend line on the front side (bottom side of wall panel)
25a Back side fourth horizontal fold line (bottom side of bottom panel)
25b Fourth horizontal fold line on the front side (lower side of the bottom panel)
31a Back wall panel 31b Front wall panel 32a Back side panel 32b Front side panel 33a Back top panel 33b Front top panel 34a Back upper overlapping panel 34b Front upper overlapping panel 35a Back bottom panel 35b Front bottom panel 36 Side seal margin 37a Back bottom seal margin 37b Front bottom seal margin 38a Back top protruding portion (ear) margin 38b Front top protruding portion (ear) margin 41a Back bottom protruding portion (ear) margin 41b Front bottom protruding portion (ear) margin 43a Back upper overlapping panel side panel 43b Front upper overlapping panel side panel 51a Back easy-open processing line (perforation line)
51b Easy-open processing line on the front side (perforation line)
52a Back zipper tape joint 52b Front zipper tape joint 61 Zipper tape 64 Male tape body 65 Female tape body 71 Top part of zippered paper container 72 Body part of zippered paper container 73 Bottom part of zippered paper container 74 Top protruding part (ear part)
75 Bottom protrusion (ear)
76: Folded portion of protruding portion (ear) on top surface 77: Notch 81: Laminated sheet of paper container 82: Damage (crack)
90 Paper container with zipper 91 Paper container with zipper in intermediate stage (flat state)
92 Paper container with zipper in intermediate stage (standing state)
95 Blank Board

θ: Bending angle of the protruding part (ear) on the top surface R: Bending radius of the protruding part (ear) on the top surface

Claims (4)

A paper container with a zipper formed by assembling blank plates made of laminated sheets having a paper base layer, wherein a side seal margin is formed at a first vertical folding line at the left and right edge portions of the blank plate,
The upper overlapping plate, the top plate, and the wall plate are sequentially arranged symmetrically above and below the intermediate horizontal folding line, with the intermediate horizontal folding line being the center of the intermediate horizontal folding line in the vertical direction of the blank plate;
The upper overlapping plate and the top plate are connected via a first horizontal folding line that crosses the blank plate in the horizontal direction,
The top panel and the wall panel are connected via a second horizontal folding line that crosses the blank plate in the horizontal direction,
A side panel is connected to the left and right sides of the wall panel via a second vertical folding line that runs vertically through the blank panel,
The upper overlapping plate is provided with an easy-open processing line and a zipper tape joint in the same order from the intermediate horizontal folding line as opening means in the horizontal direction at a position where the upper overlapping plate will overlap when folded in half at the intermediate horizontal folding line.
When the sheet is folded in half along the intermediate horizontal fold line, the zipper tape and the laminated sheet are joined at a position where the zipper tape joints are to overlap,
When folded in half at the intermediate horizontal folding line, the side seal portions of both sides that face each other are joined together,
The overlapped upper overlapping plate is left, and the lower part is spread forward and backward along a horizontal fold line, and a top part made of the top panel and a body part having a rectangular cross section connected to the lower part of the top part are formed below the standing overlapping upper overlapping plate,
The upper overlapping plate is folded back and laid down, and the top surface protruding portions protruding on both the left and right sides are folded toward the body portion, and the top surface protruding portions are joined to the body portion.
A bottom portion connected to a lower portion of the body portion is sealed,
A paper container with a zipper, characterized in that the angle θ of the bent portion that occurs when the top surface protrusions connected to both the left and right sides of the top of the paper container with a zipper are joined to the body of the paper container with a zipper is an obtuse angle. The paper container with a zipper according to claim 1, characterized in that the angle θ of the bent portion that occurs when the protruding portion on the top surface is joined to the body of the paper container with a zipper is 100° or more and 160° or less. A bottom plate is connected to the wall plate via a third horizontal folding line that crosses the blank plate in the horizontal direction,
The bottom plate and the bottom seal margins which are the upper and lower edge portions of the blank plate are connected via a fourth horizontal folding line which crosses the blank plate in the horizontal direction,
The paper container with a zipper according to claim 1 or 2, characterized in that the bottom side seal portions are joined together using a palm-to-palm seal method, the joined bottom side seal portions are folded toward the back side and laid down, and the bottom side protruding portions protruding on both the left and right sides are folded toward the bottom plate and joined. A bottom plate is connected to the wall plate via a third horizontal folding line that crosses the blank plate in the horizontal direction,
The bottom plate and the bottom seal margins which are the upper and lower edge portions of the blank plate are connected via a fourth horizontal folding line which crosses the blank plate in the horizontal direction,
a step of forming the folded shape into an intermediate stage in which the bottom sealing portion is open and unsealed;
4. A method for manufacturing a paper container with a zipper as claimed in any one of claims 1 to 3, characterized in that it includes a process of filling the bottom of the zippered paper container in an intermediate opening stage with contents, joining the bottom side seal margins together using a palm-to-palm seal method, folding the joined bottom side seal margins towards the back side and laying them down, and folding the bottom side protruding parts protruding on both the left and right sides towards the bottom plate and joining them.

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