JP6136134B2 - Paper container and manufacturing method thereof - Google Patents

Description

  The present invention relates to a paper container for storing foodstuffs, beverages, various liquids, and the like, and more particularly to a paper container having a quadrangular bottom surface and improved flatness and sealing performance of the bottom surface.

  As containers for storing food and beverages, containers of various shapes and various shapes are used. In recent years, containers using paper, which is a reproducible resource, have attracted particular attention against the background of increasing awareness of global environmental protection. Among them, paper containers that are folded into a quadrilateral bottom have a variety of food and beverages, including a cup-shaped paper container with an open top, such as a gobeltop liquid paper container found in milk cartons. It is widely used as a container for storing liquid or the like.

  The modified bottom paper cup described in Patent Document 1 has a conventional frustoconical paper cup consisting of two members, a body member and a bottom surface member, and the problem that a seal failure is likely to occur at the connection portion of the bottom surface member. This was made to solve the two problems that the stacking property is inferior due to the presence of the yarn twist portion.

JP 2003-341649 A

  The modified bottom paper cup described in Patent Document 1 is formed from a single blank, whereas a normal paper cup is composed of two members, a body part and a bottom part. It is described that the stacking property is excellent because there is no thread twist portion.

  However, since the paper cup described in Patent Document 1 has a very large amount of paper overlap on the bottom surface due to its structure, not only is the bottom surface difficult to flatten, but also pressure unevenness occurs when the bottom surface is sealed, resulting in liquid leakage due to poor sealing. There is a problem that it is easy to do.

  Another problem is that, generally, when a paper container containing contents is heated in a microwave oven, there is a problem that the bottom surface may be burnt. This problem is caused when the bottom surface is raised. In addition, it has been found that there is much overlap of paper on the bottom surface, which is likely to cause a problem when the thickness is large. Since the paper cup described in Patent Document 1 also has a large amount of overlapping of paper on the bottom surface, depending on the thickness of the paper used, there is a possibility that the paper layer may be burnt on the bottom surface when heated in a microwave oven.

  The problem to be solved by the present invention is that, in a paper container having a bottom surface portion formed in a quadrangular shape, the flatness of the bottom surface is good, seal failure is unlikely to occur, and furthermore, when heated in a microwave oven, This paper proposes a paper container structure that is less likely to burn.

As means for solving the above-mentioned problems, the invention according to claim 1 is characterized in that one flat blank 4 comprising a laminate having a paper layer and a thermoplastic resin layer provided on both sides of the paper layer. In a paper container in which a vertical ruled line of a book is folded, a body seal part is sealed, a bottom part is folded, and a rectangular bottom is formed,
Between the paper layer and the thermoplastic resin layer on the inner surface side of the container, a gas barrier layer made of a gas barrier plastic film or an inorganic oxide vapor deposition film is provided,
The plane blank has a bottom surface portion and a bottom seal portion that are successively arranged via a ruled line at the lower portion of the body portion,
The bottom surface portion includes two bottom triangular plates whose long sides are connected to the lower portion of the trunk and two large and small bottom rectangular plates whose long sides are connected to the lower portion of the trunk, and one side of the bottom rectangular plate and the bottom surface are alternately arranged. Four bottom folding plates connected to the short side of the triangular plate are provided via ruled lines,
The bottom seal portion is continuously provided via a ruled line from the bottom rectangular plate and the bottom folded plate, and is composed of a bottom seal plate group separated from each other by a bottom seal portion vertical fold ruled line,
The bottom rectangular plate (small) paper layer to be removed by the paper layer of the portion corresponding to the two bottom seal plate adjacent to the bottom seal plate that is connected is in the rafter seal portion is removed from the twofold seal It is a paper container characterized by being only a portion to be made .

  The paper container according to the present invention is formed by removing the paper layer corresponding to the two bottom seal plates of the bottom seal plate group when folding the lower portion of one plane blank to form a flat bottom surface. The stacking of the laminates was reduced. For this reason, the flatness of the bottom surface is improved, the sealing property of the bottom surface is improved, and the occurrence of scorching when heated in a microwave oven is reduced.

  Further, the invention according to claim 2 does not provide the four vertical ruled lines in the body part up to the upper end of the body part, forms the upper end of the body part into a circular flange part, seals the lid material, and cup type The paper container according to claim 1, wherein the paper container is a container.

Further, an invention according to claim 3, the paper layer and, have a thermoplastic resin layer provided on both sides of the paper layer, the paper barrier layer made of plastic film or an inorganic oxide deposited film of the gas barrier properties Fold four vertical ruled lines of one plane blank made of a laminate provided between the layer and the thermoplastic resin layer on the inner surface side of the container, seal the body seal part, and fold the bottom part In the method of manufacturing a paper container that forms a rectangular bottom surface,
The plane blank has a bottom surface portion and a bottom seal portion that are successively arranged via a ruled line at the lower portion of the body portion,
The bottom surface portion includes two bottom triangular plates whose long sides are connected to the lower portion of the trunk and two large and small bottom rectangular plates whose long sides are connected to the lower portion of the trunk, and one side of the bottom rectangular plate and the bottom surface are alternately arranged. Four bottom folding plates connected to the short side of the triangular plate are provided via ruled lines,
The bottom seal portion is continuously provided via a ruled line from the bottom rectangular plate and the bottom folded plate, and is composed of a bottom seal plate group separated from each other by a bottom seal portion vertical fold ruled line,
Twofold paper layer removed by said bottom rectangular plate (small) rafter seal portion parts the paper layer is removed in portions corresponding to the two bottom seal plate adjacent to the bottom seal plate which is articulated from A method for manufacturing a paper container, characterized in that only a seal portion is provided.

  In the paper container according to the present invention, when the flat bottom surface is formed by folding the lower part of one plane blank, the overlap of the laminates on the bottom surface portion is reduced by removing a part of the paper layer of the bottom surface seal portion. It was. For this reason, the flatness of the bottom surface was improved, and the stability and self-supporting property of the container were improved.

  In addition, since only a part of the paper layer in the bottom seal portion was removed and the thermoplastic resin layers on the front and back surfaces of the paper layer were left, the sealing performance at the bottom surface was improved and the occurrence of poor sealing was reduced.

  Moreover, since the paper container which concerns on this invention folded the lower part of one plane blank and formed the flat bottom face, unlike a normal paper cup, a bottom sleeve does not exist. For this reason, when it is heated in a microwave oven, it is basically difficult for scorching to occur. However, by removing a part of the paper layer on the bottom seal portion, scoring is less likely to occur.

  In addition, since the body portion and the bottom portion include a paper layer, there is an insulating property, and therefore, there is an advantage that a hand is not hot in handling during heating as compared with a metal can or a glass bottle.

FIG. 1 is a perspective view showing an embodiment of a paper container according to the present invention. FIG. 2 is a schematic plan view showing a flat blank of the paper container shown in FIG. FIG. 3 is a perspective view showing a state where the paper container shown in FIG. 1 is viewed from below, and is a perspective view showing a state before the bottom rectangular plate (10) is folded. FIG. 4 is a perspective view showing a state where the paper container shown in FIG. 1 is viewed from below. FIG. 5 is a schematic cross-sectional view showing the X-X ′ cross section of FIG. 4. FIG. 6 is a schematic cross-sectional view showing the Y-Y ′ cross section of FIG. 4. FIG. 7 is an explanatory view showing a method of manufacturing a paper container according to the present invention. FIG. 8 is a perspective view showing another embodiment of the paper container according to the present invention. FIG. 9 is a schematic plan view showing a flat blank of the paper container shown in FIG.

Hereinafter, a paper container according to the present invention will be described in detail with reference to the drawings.
FIG. 1 is a perspective view showing an embodiment of a paper container according to the present invention, which is an example of a cup-type paper container. FIG. 2 is a schematic plan view showing a flat blank of the paper container shown in FIG. 3 and 4 are perspective views showing the paper container shown in FIG. 1 as viewed from below.
This will be described below with reference to these drawings.

  The paper container (C) according to the present invention comprises four vertical ruled lines (cylinders) of one plane blank (BL) made of a laminate having a paper layer and a thermoplastic resin layer provided on both sides of the paper layer. A paper container formed by folding a part seal part crease line (a) and vertical crease line (b, c, d)), sealing a body part seal part, and folding a bottom part (4). It is.

  The planar blank (BL) has a bottom surface portion (4) and a bottom seal portion (5) that are sequentially provided below the body portion (3) via ruled lines.

  The bottom surface part (4) has two bottom triangular plates (7, 8) whose long sides are connected to the lower part of the trunk part, and two large and small bottom rectangular plates (9, 10) whose long sides are connected to the lower part of the trunk part. Four bottom folded plates (11, 12, 13, and 14) that are alternately arranged and are connected to one side of the bottom rectangular plate and the short side of the bottom triangular plate are provided via ruled lines.

  The bottom seal portion (5) is connected to the bottom rectangular plate (9, 10) and the bottom folded plate (11-14) via a ruled line, and is divided from the bottom seal plate group separated from each other by the bottom seal portion vertical folded ruled line. It is configured.

  The paper container (C) according to the present invention has a bottom surface from which a paper layer corresponding to two bottom seal plates adjacent to a bottom seal plate (15) connected from a bottom rectangular plate (small) (9) is removed. The paper container is characterized in that notches (16a, 16b) are formed.

  In the bottom cut-out portions (16a, 16b), only the paper layer of the laminate is removed, and the thermoplastic resin layers on the front and back sides are bonded to one layer.

  5 and 6 are cross-sectional schematic views showing the X-X 'cross section and the Y-Y' cross section of FIG. 4, respectively. As can be seen from these figures, the overlapping of the laminated body in the bottom surface portion (4) is as many as eight layers.

  The overlap of the laminated bodies varies depending on the location of the bottom surface portion (4), and conversely, there is one layer in the smallest portion. The unevenness of the overlapping of the laminates is a major cause of impairing the flatness of the bottom surface.

By removing only the paper layer that occupies most of the thickness of the laminate, the thickness of the bottom surface can be reduced while reducing the thickness unevenness at the bottom without compromising the formability of the bottom. can do. It has been found that this improves the flatness of the bottom surface, increases the self-supporting property of the paper container, and helps prevent the occurrence of scorching when heated by a microwave oven.

  As a result of various studies on which part of the paper layer of the bottom surface portion (4) is removed, the inventor has found that the two bottom seal plates (15) connected to the bottom surface rectangular plate (small) (9) are adjacent to each other. It has been found that it is most effective to remove the paper layer corresponding to the bottom seal plate, and the present invention has been completed.

  The paper container (C) according to the present invention has a flat bottom surface and does not have a bottom sleeve like a normal paper cup. For this reason, when heated in a microwave oven, scorching is unlikely to occur.

  The paper container (C) according to the present invention has a heat insulating property because the body portion (3) and the bottom surface portion (4) include a paper layer. Therefore, in handling during heating compared to a metal can or a glass bottle, There are advantages such as not hot hands. There is also an advantage that the contents are difficult to cool.

  Further, when forming the bottom surface, the paper layer corresponding to the two bottom surface seal plates adjacent to the bottom surface seal plate (15), which is the portion where the paper thickness is locally thickest, is removed. ), The bottom surface was finished flat, and the stability and independence of the container increased.

  In addition, since the sealing performance of the bottom surface portion (4) has been improved, the occurrence of liquid leakage due to poor sealing has been improved.

  The procedure for forming the paper container (C) according to the present invention will be described with reference to FIGS. The plan blank view of FIG. 2 is a view as seen from the surface side of the laminate that is the outside of the container. A solid line indicates an outline line, a thin solid line indicates a mountain fold ruled line, and an alternate long and short dash line indicates a valley fold ruled line. Dotted lines indicate ruled lines that are folded in the middle process but not folded in the final finished state.

  First, a flat blank (BL) is wound and the left body seal plate (6) and right end are overlapped and sealed, and the body seal section crease line (a) and vertical crease line (b, c, d) are drawn. Fold to form a cylindrical body. In this example, the front and back surfaces of the left and right body end portions are sealed, but the back surfaces may be sealed together. By sealing the back surfaces together and then bending them along the body part, it is possible to make a structure in which the end of the laminate is not exposed on the inner surface of the container.

  Next, the bottom surface portion (4) is folded to form the bottom surface. First, the bottom corner crease line (e, f, g, h), the bottom crease ruled line (m, n, o, p) and the bottom seal part vertical crease line (t, v, w, y) are folded in a mountain, and at the same time the bottom face Triangular plate folding ruled lines (i, j, k, l) are valley-folded and the bottom folded plates (11, 12, 13, 14) are folded onto the bottom triangular plate (7, 8) to form the bottom surface.

  After the bottom seal portion (5) is joint-sealed, the bottom seal portion folding ruled line (r) is folded 180 ° to bond the bottom seal portion to the bottom rectangular plate (small) (9) to obtain a flat bottom surface. At this time, the bottom rectangular plate (large) (10) forms most of the bottom surface.

  FIG. 5 is a schematic cross-sectional view showing the X-X ′ cross section of FIG. 4. This cross-sectional position is a position slightly shifted from the center of the bottom surface toward the bottom corner crease line (f), and is the position where the overlap of the laminates is the largest. In FIG. 5, eight laminates are laminated at the bottom corner crease line (e), and seven laminates are laminated at the bottom corner crease line (g).

FIG. 6 is a schematic cross-sectional view showing the YY ′ cross section of FIG. 3. This cross-sectional position is also a position slightly shifted from the center of the bottom surface toward the bottom corner crease line (e), and is the position where the stacks are most overlapped. In FIG. 6, a maximum of seven laminated bodies are laminated.

  The inventor has a bottom surface between the bottom seal part vertical crease line (u) and the bottom seal part vertical crease line (v) and between the bottom seal part vertical fold rule line (w) and the bottom seal part vertical crease line (x). The present inventors have found that the portions corresponding to the seal plates are the bottom surface notches (16a) and (16b), respectively, and that a flat bottom surface can be easily formed by removing the paper layer at these portions.

  As described above, in the paper container of this structure, it has been difficult to form a flat bottom surface because there is a large amount of stacking of the laminated body in the bottom surface portion, but a portion adjacent to the bottom surface seal plate (15). It has been found that the flatness and the sealing performance of the bottom surface are improved by using the bottom surface notch portions (16a, 16b).

  The opening of the paper container (C) is usually crushed after being curled to form a flange (21). An arbitrary lid material can be heat-sealed to the flange portion (21) to form a sealed container. It may be used as a simple paper cup by holding the opening in a curled state without using the flange.

FIG. 7 is an explanatory view showing a method for producing a paper container (C) according to the present invention.
The register mark (31) is printed simultaneously with the predetermined printing on the base paper (30). In this example, the plane blank (BL) is allocated to two lines on the base paper (30).

  Next, while aligning using the register mark (31), a hole (32) including a portion corresponding to the bottom surface notch portions (16a) and (16b) of the flat blank of the printed base paper (30) is formed. To do. The holes (32) are provided so as to slightly protrude outside the flat blank (BL).

  Next, a thermoplastic resin layer is bonded to the front and back surfaces of the perforated base paper. In the hole (32) portion, the thermoplastic resin layers on the front and back surfaces are bonded to each other.

  Finally, similarly, the register mark (31) is used for alignment, a crease line is inserted, and a blank shape (BL) is obtained by punching out into an outer contour shape.

FIG. 8 is a perspective view showing another embodiment of the paper container (C) according to the present invention, and FIG. 9 is a plan view showing the plane blank (BL) of the paper container (C) shown in FIG. It is a schematic diagram.
The paper container (C) shown in FIGS. 8 and 9 is an example in which the configuration of the present invention is applied to a general liquid paper container with a gable top type stopper. The structure of the body part (3) and the bottom part (4) is the same as that of the paper container shown in FIG. 1, but the top part (2) is formed into a roof mold having a top seal part (1), A plug (22) is attached to the roof surface.

  In the examples shown in FIGS. 8 and 9, the flatness of the bottom surface is improved and the stability when the paper container is placed on a horizontal base is improved as compared with the conventional paper container having no bottom notch. To do. Moreover, the occurrence of liquid leakage due to poor sealing can be suppressed.

  As a laminate used for the paper container (C) according to the present invention, in addition to the thermoplastic resin layer provided on the front and back surfaces of the paper layer, between the paper layer and the thermoplastic resin layer on the inner surface side of the container, Those provided with a gas barrier layer can also be used. The presence of the gas barrier layer improves the storage stability after the container is filled with the contents. By appropriately selecting the material of the gas barrier layer, a product that can be stored at room temperature for a long time can be obtained.

The paper layer, other conventional cup base paper, white cardboard, coated cardboard, the basis weight of 160g ^{/ m 2} ~400g ^/ m 2 about paper ivory paper, etc. can be used.

  As the thermoplastic resin layer, polyolefin resin is generally used. Specifically, low density polyethylene, medium density polyethylene, linear low density polyethylene, ethylene / vinyl acetate copolymer, ethylene / α olefin copolymer are used. Polymers, ethylene resins such as ethylene-methacrylic acid resin copolymers, blend resins of polyethylene and polybutene, homopolypropylene, propylene / ethylene random copolymers, propylene / ethylene block copolymers, propylene / α-olefins A polypropylene resin such as a copolymer is used.

  As the material of the gas barrier layer, when heating by a microwave oven is assumed, it is preferable to use a material other than metal foil, such as a gas barrier plastic film or an inorganic oxide vapor deposition film, but heating by a microwave oven is assumed. If not, a metal foil such as an aluminum foil can be used.

  Examples of the gas barrier film include a polyvinylidene chloride film, a polyvinyl alcohol film, an ethylene vinyl alcohol copolymer film, a gas barrier nylon film, a gas barrier polyethylene terephthalate film and the like, a PET film and the like such as aluminum oxide and silicon oxide. An inorganic oxide vapor-deposited film on which an inorganic oxide is deposited, or a polyvinylidene chloride coating, a film containing a water-soluble resin and an inorganic layered compound, or a film obtained by reacting a metal alkoxide or its hydrolyzate with an isocyanate compound. A gas barrier coating layer such as a resin layer can be used.

  Hereinafter, although the paper container concerning the present invention is explained based on an example, the paper container concerning the present invention is not limited to this.

A pattern and a register mark were printed on the surface of a cup base paper having a basis weight of 260 g / m ^{2 in} the layout as shown in FIG. After a laminate of (polyethylene 12 μm / silica vapor-deposited PET 12 μm / low density polyethylene 60 μm) was adhered to the back surface, a 20 μm thick medium density polyethylene (MDPE) layer was formed on the surface using an extruder. A ruled line was put in this using a drawing die, and a flat blank as shown in FIG. 2 was created. The thickness of the laminate is 0.4 mm, and the thickness at the bottom notch is about 0.1 mm.

  The bottom surface of the obtained flat blank was molded by a molding machine, and a cup-shaped paper container having a shape as shown in FIG. 1 was produced. The flatness and stability of the bottom surface of the container were good.

  The paper container was placed on a normal cup filling line, the liquid was stored, and the lid was heat sealed. The sealing property was good and no liquid leakage occurred.

  When the lid of the package was partially opened and heated by a microwave oven, the container did not rupture and did not burn.

C ... Paper container BL ... Flat blank 1 ... Top seal part 2 ... Top face part 3 ... Body part 4 ... Bottom part 5 ... Bottom seal part 6 ... Body part Seal plates 7, 8 ... Bottom triangle plate 9 ... Bottom rectangle plate (small)
10 ... Bottom rectangular plate (large)
11, 12, 13, 14 ... bottom folding plate 15 ... bottom seal plates 16a, 16b ... bottom notch 21 ... flange 22 ... plug 23 ... plug attachment hole a ... Body seal part crease lines b, c, d ... Vertical fold rule lines e, f, g, h ... Bottom corner crease lines i, j, k, l ... Bottom triangle plate folded crease lines m, n, o, p... bottom fold ruled line q, s... bottom crease ruled line q ', r', s' .. bottom seal part temporary crease line r ... bottom seal part fold ruled line t , U, v, w, x, y ... bottom seal part vertical folding ruled line 30 ... base paper 31 ... register mark 32 ... hole

Claims (3)

Four vertical ruled lines of one plane blank made of a laminate having a paper layer and a thermoplastic resin layer provided on both sides of the paper layer are folded, the body seal part is sealed, and the bottom part is folded. In a paper container formed with a rectangular bottom surface,
Between the paper layer and the thermoplastic resin layer on the inner surface side of the container, a gas barrier layer made of a gas barrier plastic film or an inorganic oxide vapor deposition film is provided,
The plane blank has a bottom surface portion and a bottom seal portion that are successively arranged via a ruled line at the lower portion of the body portion,
The bottom surface portion includes two bottom triangular plates whose long sides are connected to the lower portion of the trunk and two large and small bottom rectangular plates whose long sides are connected to the lower portion of the trunk, and one side of the bottom rectangular plate and the bottom surface are alternately arranged. Four bottom folding plates connected to the short side of the triangular plate are provided via ruled lines,
The bottom seal portion is continuously provided via a ruled line from the bottom rectangular plate and the bottom folded plate, and is composed of a bottom seal plate group separated from each other by a bottom seal portion vertical fold ruled line,
The bottom rectangular plate (small) paper layer to be removed by the paper layer of the portion corresponding to the two bottom seal plate adjacent to the bottom seal plate that is connected is in the rafter seal portion is removed from the twofold seal A paper container characterized in that it is only a part to be made .   The four vertical ruled lines in the body portion are not provided to the upper end of the body portion, the upper end of the body portion is formed into a circular flange portion, the lid material is sealed, and a cup type container is formed. A paper container as described in 1. A paper layer, have a thermoplastic resin layer provided on both sides of the paper layer, the thermoplastic resin of the gas barrier layer made of plastic film or an inorganic oxide deposited film of the gas barrier the paper layer and the container inner surface Manufacturing of a paper container that forms a rectangular bottom by folding four vertical ruled lines of a plane blank made of a laminate provided between the layers, sealing the body seal, and folding the bottom In the method
The plane blank has a bottom surface portion and a bottom seal portion that are successively arranged via a ruled line at the lower portion of the body portion,
The bottom surface portion includes two bottom triangular plates whose long sides are connected to the lower portion of the trunk and two large and small bottom rectangular plates whose long sides are connected to the lower portion of the trunk, and one side of the bottom rectangular plate and the bottom surface are alternately arranged. Four bottom folding plates connected to the short side of the triangular plate are provided via ruled lines,
The bottom seal portion is continuously provided via a ruled line from the bottom rectangular plate and the bottom folded plate, and is composed of a bottom seal plate group separated from each other by a bottom seal portion vertical fold ruled line,
Twofold paper layer removed by said bottom rectangular plate (small) rafter seal portion parts the paper layer is removed in portions corresponding to the two bottom seal plate adjacent to the bottom seal plate which is articulated from A method for manufacturing a paper container, characterized in that only a seal portion is provided .

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