Packaging container and cutting method for laminate

Abstract

To provide a container having an end part coated with an intermediate resin layer having a novel structure.SOLUTION: A packaging container 1 has an end part 112 formed by cutting a joint 23 at which laminates 2 each including first layers 21 and a second layer 22 sandwiched between the first layers 21, are joined together. The end part 112 has an inner layer 24 formed by overlapping two first layers 21 as a result of the laminates 2 being joined together, one first layer 21 and the inner layer 24 which are outer layers, and the other first layer 21 and the inner layer 24 which are outer layers are joined together to cover the second layer 22.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present invention relates to a method for cutting a packaging container and a laminate.

Background Art

[0002] Containers composed of a plurality of resin layers, including a resin layer having physical properties and gas barrier properties, are known. Usually, in a container composed of a plurality of resin layers, the resin layer having physical properties and gas barrier properties is configured as an intermediate resin layer. When a container composed of a plurality of resin layers is cut by a normal method, the intermediate resin layer at the cut surface is exposed to the outside. Depending on the material contained in the intermediate resin layer, there has been a problem that the appearance and quality of the container gradually deteriorate due to the exposure to the outside, and finally the container no longer functions as a container. Therefore, methods have been proposed to prevent the intermediate resin layer on the cut surface of the container from being exposed to the outside.

[0003] Patent Document 1 describes a method for cutting a laminate in which a plurality of resin layers are laminated into a predetermined shape, wherein at least one layer of the resin constituting the laminate cuts the laminate in a molten state.

[0004] Patent Document 2 describes an oxygen-absorbing multilayer sheet laminated in a layer structure of a thermoplastic resin layer (B) / oxygen-absorbing layer (A) / porous layer or oxygen-permeable resin layer (C), and a multilayer sheet molded body in which the sheet end face is completely covered with the thermoplastic resin layer (B), and it is described that punching was performed with a punching blade having a diameter of 50 mm heated to 80 °C (having a taper angle of about 30 ° inside) and a mortar-shaped receiving blade (the slope of the inclined surface of the mortar is about 45 °).

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0006] In view of the above prior art, an object of the present invention is to provide a container having a novel structure in which an intermediate resin layer is coated at an end portion. Further, in the above prior document, it is necessary to melt at least one of the resins constituting the multilayer body, and it is necessary to heat the punching blade and the receiving blade to 80°C. Therefore, another object of the present invention is to provide a novel method for cutting a laminate that does not require the above-described configuration.

Means for Solving the Problems

[0007] The present invention for solving the above problems relates to the following method for cutting a laminate and a container. [1] A packaging container having an end portion formed by cutting a joint portion where laminates each including a first layer and a second layer sandwiched between the first layers are joined, wherein the end portion has an inner layer formed by overlapping the two first layers when the laminates are joined, and the second layer is covered by joining one of the first layers as an outer layer and the inner layer, and the other of the first layers as an outer layer and the inner layer.

[0008] [2] The packaging container according to [1], wherein the second layer is a layer containing a functional resin.

[0009] [3] The packaging container according to [2], wherein the first layer is a layer containing a water-resistant resin, and the second layer is a layer containing a resin having functionality and water solubility.

[0010] [4] The packaging container according to any one of [1] to [3], wherein the packaging container is a tube container.

[0011] [5] A method for manufacturing the packaging container according to [1], comprising a cutting step of cutting the joint portion with a cutting blade from one direction, and applying a force from a direction opposite to the cutting direction of the cutting blade in the cutting step.

[0012] [6] The method according to [5], wherein in the cutting step, a force is applied from a direction opposite to the cutting direction using a receiving blade.

[0013] [7] The method according to [6], wherein in the cutting step, the cutting blade and the receiving blade are moved at a predetermined relative speed.

[0014] [8] The method according to [7], wherein in the cutting step, the cutting blade and the receiving blade are moved at a relative speed of 50 mm / sec or more and 1000 mm / sec or less to cut the laminate.

[0015] [9] The cutting step of the laminate according to any one of [5] to [8], wherein the cutting step cuts the joint portion so that the first layer covers the second layer.

[0016]

[10] The method according to any one of [5] to [8], wherein in the cutting step, the first layer and the second layer are at a temperature lower than the melting points of the first layer and the second layer.

[0017]

[11] A method for cutting a laminate in which joints between laminates each including a first layer and a second layer sandwiched between the first layers are joined, the method comprising a cutting step of cutting the joint portion with a cutting blade from one direction, and in the cutting step, applying a force from a direction opposite to the cutting direction of the cutting blade.

[0018]

[12] The method for cutting a laminate according to

[11] , wherein in the cutting step, a force is applied from a direction opposite to the cutting direction using a receiving blade.

[0019]

[13] The method for cutting a laminate according to

[12] , wherein in the cutting step, the cutting blade and the receiving blade are moved at a predetermined relative speed.

[0020]

[14] The method for cutting a laminate according to

[13] , wherein in the cutting step, the cutting blade and the receiving blade are moved at a relative speed of 50 mm / sec or more and 1000 mm / sec or less to cut the laminate.

[0021]

[15] The method for cutting a laminate according to any one of

[11] to

[14] , wherein in the cutting step, the joint is cut so that the first layer covers the second layer.

[0022]

[16] The method for cutting a laminate according to any one of

[11] to

[14] , wherein in the cutting step, the first layer and the second layer are at a temperature lower than the melting points of the first layer and the second layer.

Advantages of the Invention

[0023] According to the present invention, at the end portion, a container having a novel structure in which an intermediate resin layer is covered can be provided.

Brief Description of the Drawings

[0024]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0025] <1> Packaging Container Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments shown below are examples of the present invention, and the present invention is not limited to the following embodiments.

[0026] As shown in FIG. 1, the packaging container 1 according to this embodiment includes a container body 11. The container body 11 includes a body portion 111 and an end portion 112.

[0027] In this embodiment, the body portion 111 is constituted by a laminate 2 having a sagittal cross section shown in FIG. 2.

[0028] In this embodiment, the laminate 2 includes a first layer 21 and a second layer 22 sandwiched between the first layers.

[0029] In this embodiment, the first layer 21 is constituted by a layer containing low-density polyethylene. In the present invention, the first layer 21 is not particularly limited as long as it is a material used for ordinary packaging containers, but contains a polyolefin resin, a polyester resin, a nylon resin, an ethylene vinyl acetate copolymer, and / or an olefin elastomer.

[0030] Examples of the polyolefin resin include polyethylene copolymers, polypropylene copolymers, and butene copolymers. Among these, polyethylene copolymers and polypropylene copolymers are preferred.

[0031] In this embodiment, the second layer 22 is constituted by a layer containing polyvinyl alcohol. In the present invention, the second layer 22 is not particularly limited as long as it is a material used for ordinary packaging containers, but preferably contains a functional resin, and more preferably contains a gas barrier resin. Further, since it is preferable that the resin has water solubility to form a packaging container suitable for recycling after use, the second layer 22 more preferably contains a resin that is a functional resin and a water-soluble resin.

[0032] In the present invention, the functional resin refers to a resin having a function of improving the storability of the contents by blocking oxygen, water vapor, etc.

[0033] In the present invention, when the second layer 22 is a functional resin and a water-soluble resin, the first layer 21 is preferably a water-resistant resin. With the above configuration, it is possible to prevent the second layer 22 from getting wet with water and losing its functionality.

[0034] Examples of the gas barrier resin include polyamide, ethylene-vinyl alcohol copolymer, polyvinyl alcohol, polyacrylonitrile, polyester, polyurethane, vinylidene chloride, nylon 6, nylon 6,6, and polymetaxylylene adipamide. One or more of these can be used.

[0035] In the present invention, the laminate 2 may include an adhesive layer between the first layer 21 and the second layer 22. The adhesive layer is composed of an adhesive. The adhesive may be any of a one-component curable adhesive, a two-component curable adhesive, and a non-curable adhesive. The adhesive may be a solventless adhesive or a solvent-based adhesive.

[0036] Fig. 3(a) shows a sagittal cross-section of the joint portion 23 where the laminates 2 in the present embodiment are joined. The joint portion 23 is preferably formed by joining the laminate 2 and another laminate 2 via the first layer 21. In the present embodiment, it is preferable to weld the laminates 2 to each other by heat at the joint portion 23. Further, in order to maintain the adhesive strength, it is preferable to cool immediately after welding by heat.

[0037] As shown in Fig. 3(b), in the present embodiment, the end portion 112 is formed by cutting the joint portion 23.

[0038] The end portion 112 specifically includes an inner layer 24 formed by overlapping two first layers 21 when the laminates 2 are joined together. The second layer 22 is covered by joining one first layer 21 which is an outer layer and the inner layer 24, and the other first layer 21 which is an outer layer and the inner layer 24.

[0039] As another embodiment of the present invention, a form in which the inner layer 24 is extruded upward can also be mentioned.

[0040] The packaging container 1 of the present invention is not particularly limited, but is preferably a tube container. When filling the tube container with the content and closing the end portion, the second layer 22 is in a state of being in two places at the end portion 112. According to the present invention, by joining one first layer 21 which is an outer layer and the inner layer 24, and the other first layer 21 which is an outer layer and the inner layer 24, problems (such as deterioration of appearance and reduction of functionality) caused by the exposure of the two second layers 22 to the outside can be prevented.

[0041] The tube container includes a tube formed by winding a laminated film, and a tube formed by extruding a molten resin.

[0042] The packaging container 1 provided with the end portion 112 in the present embodiment can be manufactured, for example, by using a cutting method described later.

[0043] <2> Cutting method of laminate Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the embodiments shown below are examples of the present invention, and the present invention is not limited to the following embodiments.

[0044] The cutting method of the present invention is a cutting method of a laminate in which joined portions where laminates including a first layer and a second layer sandwiched between the first layers are joined together are cut, and includes a cutting step of cutting the joined portions with a cutting blade from one direction, and in the cutting step, a force is applied from a direction opposite to the cutting direction of the cutting blade. Here, since the above-mentioned "<1> packaging container" is an invention related to the cutting method of the present invention, the content described in the above <1> can be incorporated by reference.

[0045] In the present embodiment, a method for cutting the laminate 2 in which the laminates 2 including the first layer 21 shown in FIG. 3(a) and the second layer 22 sandwiched between the first layers 21 are joined together at the joint 23 will be described.

[0046] FIG. 4 is a view showing a cutting step of cutting the joint 23 with the cutting blade 3 from one direction in the present embodiment.

[0047] FIG. 4(a) is a view showing the state immediately before cutting the joint 23. The cutting blade 3 is moved at an angle perpendicular to the layer direction of the joint 23. At this time, the receiving blade 4 is moved from the direction opposing the traveling direction of the cutting blade 3.

[0048] FIG. 4(b) is a view showing the state during the cutting of the joint 23. When cutting the joint 23 with the cutting blade 3 from one direction, a force is applied from the direction opposing the cutting direction of the cutting blade 3. Specifically, a force is applied by moving the receiving blade 4 from the direction opposing the cutting direction of the cutting blade 3.

[0049] Within the range where the effects of the present invention are exhibited, there is no particular limitation on the speed at which the cutting blade 3 is moved, but the cutting blade 3 is preferably moved at a speed of 10 mm / sec or more, more preferably 30 mm / sec or more, still more preferably 60 mm / sec, even more preferably 100 mm / sec or more, and even more preferably 150 mm / sec or more.

[0050] In the present invention, when referring to speed, it may refer to the average speed obtained by dividing the moved distance by the moved time, or it may refer to the maximum speed.

[0051] Also, within the range where the effects of the present invention are exhibited, there is no particular limitation on the speed at which the receiving blade 4 is moved. However, the receiving blade 4 is preferably moved at a speed of 10 mm / sec or more, more preferably 30 mm / sec or more, still more preferably 60 mm / sec, even more preferably 100 mm / sec or more, even more preferably 150 mm / sec or more, and even more preferably 250 mm / sec or more.

[0052] Also, within the range where the effects of the present invention are exhibited, it is preferable to move the cutting blade 3 and the receiving blade 4 at a predetermined relative speed. The cutting blade 3 and the receiving blade 4 are preferably moved at a relative speed of 50 mm / sec or more, more preferably 100 mm / sec or more, still more preferably 140 mm / sec or more, even more preferably 300 mm / sec or more, and even more preferably 400 mm / sec or more.

[0053] Also, within the range where the effects of the present invention are exhibited, it is preferable to move the cutting blade 3 and the receiving blade 4 at a predetermined relative speed. The cutting blade 3 and the receiving blade 4 are preferably moved at a relative speed of 1000 mm / sec or less, more preferably 900 mm / sec or less, still more preferably 800 mm / sec or less, even more preferably 700 mm / sec or less, and even more preferably 600 mm / sec or less, and even more preferably 500 mm / sec or less.

[0054] In the present embodiment, it is preferable to cut the joint portion 23 so that the first layer 21 covers the second layer 22.

[0055] FIG. 4(c) is a view showing the state immediately after cutting the joint portion 23.

[0056] When cutting the joint portion 23, the temperatures of the first layer 21 and the second layer 22 are not particularly limited, but are preferably 30°C or more, and more preferably 40°C or more.

[0057] Also, when cutting the joint 23, the temperatures of the first layer 21 and the second layer 22 are preferably lower than the melting points of the first layer 21 and the second layer 22, preferably 60°C or lower, and more preferably 55°C or lower. According to the present invention, even when the first layer 21 and the second layer 22 are not in a molten state, the first layer 21 can be coated on the second layer 22.

[0058] The present invention including the above cutting step can coat the second layer 22 with the first layer 21 without melting the resin or heating the cutting blade 3. When the second layer 22 is a functional resin layer and a water-soluble resin layer, coating the second layer 22 with the first layer 21 can prevent the deterioration of the second layer 22 even when the joint 23 is wetted with water.

[0059] As another embodiment of the present invention, in the cutting step, a force can be applied by moving the receiving blade 4 further into the container from the direction opposite to the cutting direction of the cutting blade 3. By adopting the above form, a packaging container 1 having an end portion 112 where the inner layer 24 is extruded upward can be obtained.

Example

[0060] Hereinafter, the present invention will be specifically described with reference to examples.

[0061] As a test sample, an extrusion tube obtained by a method of manufacturing a container body of a tube container by extrusion molding, which is commonly known, was used. Here, the end portion (corresponding to the joint of the present invention) of the extrusion tube is welded by heat.

[0062] The following materials shown in Table 1 were used for the end portion. Note that the order of description in the material column of Table 1 represents the layer structure of the end portion. In Table 1, low-density polyethylene was used as resin A, and polyvinyl alcohol was used as the gas barrier layer.

[0063]

Table 1

[0064] Next, the said end portion was cut by a cutting blade and a receiving blade. Here, when cutting the said end portion with the cutting blade from one direction, a force was applied from the direction opposing the cutting direction of the cutting blade. Also, the temperature of the said end portion was in the range of 40 to 60°C.

[0065] Table 2 shows the results indicating the relationship between the speed of moving the cutting blade and the receiving blade and the exposure rate of the gas barrier layer when looking directly down at the cut surface of the said end portion. Note that the exposure rate means the ratio of the area of the gas barrier layer in the entire area of the cut surface when looking directly down at the cut surface of the said end portion.

[0066]

Table 2

[0067] As shown in Table 2, it was found that when cutting the said end portion with the cutting blade from one direction, by applying a force from the direction opposing the cutting direction of the cutting blade, the exposure rate of the gas barrier layer can be reduced.

[0068] Furthermore, when cutting the said end portion with the cutting blade from one direction, images of the sagittal cross-section where a force was applied from the direction opposing the cutting direction of the cutting blade and the sagittal cross-section where this was not done are shown in FIGS. 5(a) and (b). Here, in order to make the gas barrier layer easily visible, the gas barrier layer was colored from the horizontal plane of the said end portion.

[0069] As shown in FIG. 5, in the sagittal cross-section (FIG. 5(a)) where a force was applied from the direction opposing the cutting direction of the cutting blade when cutting the said end portion with the cutting blade from one direction, it can be seen that the gas barrier layer is covered with resin A. This can also be understood from the fact that, although the gas barrier layer was colored from the horizontal plane of the said end portion, the gas barrier layer is not completely colored because the gas barrier layer is covered with resin A. On the other hand, in the sagittal cross-section where this was not done (FIG. 5(b)), as can also be seen from the fact that the gas barrier layer is colored black, the gas barrier layer is not covered with resin A.

Industrial Applicability

[0070] The present invention can be applied to a method for cutting a laminate and a container.

Explanation of Reference Numerals

[0071] 1 Packaging container 11 Container body 111 Barrel part 112 End part 2 Laminate 21 First layer 22 Second layer 23 Joint part 24 Inner layer 3 Cutting blade 4 Receiving blade

Claims

1. A packaging container having an end formed by cutting a joint where laminates each including a first layer and a second layer sandwiched between the first layers are joined together, wherein the end includes an inner layer formed by overlapping the two first layers when the laminates are joined together, and the second layer is covered by joining one of the first layers, which is an outer layer, and the inner layer, and the other first layer, which is an outer layer, and the inner layer.

2. The packaging container according to claim 1, wherein the second layer is a layer containing a functional resin.

3. The first layer is a layer containing a water-resistant resin, and the packaging container according to claim 2, wherein the second layer is a layer containing a resin having functionality and water solubility.

4. The packaging container according to any one of claims 1 to 3, wherein the packaging container is a tube container.

5. A method for manufacturing the packaging container according to claim 1, the method comprising a cutting step of cutting the joint from one direction with a cutting blade, and applying a force in a direction opposite to the cutting direction of the cutting blade in the cutting step.

6. The method according to claim 5, wherein in the cutting step, a force is applied in a direction opposite to the cutting direction using a receiving blade.

7. The method according to claim 6, wherein in the cutting step, the cutting blade and the receiving blade are moved at a predetermined relative speed.

8. The method according to claim 7, wherein in the cutting step, the cutting blade and the receiving blade are moved at a relative speed of 50 mm / sec or more and 1000 mm / sec or less to cut the laminate.

9. The cutting step cuts the joint so that the first layer covers the second layer, according to any one of claims 5 to 8.

10. In the cutting step, the first layer and the second layer are at a temperature lower than the melting points of the first layer and the second layer, according to any one of claims 5 to 8.

11. A method for cutting a laminate that cuts a joint where laminates each including a first layer and a second layer sandwiched between the first layers are joined together, the method comprising a cutting step of cutting the joint from one direction with a cutting blade, and applying a force in a direction opposite to the cutting direction of the cutting blade in the cutting step.

12. The method for cutting a laminate according to claim 11, wherein in the cutting step, a force is applied in a direction opposite to the cutting direction using a receiving blade.

13. The method for cutting a laminate according to claim 12, wherein in the cutting step, the cutting blade and the receiving blade are moved at a predetermined relative speed.

14. The method for cutting a laminate according to claim 13, wherein in the cutting step, the cutting blade and the receiving blade are moved at a relative speed of 50 mm / sec or more and 1000 mm / sec or less to cut the laminate.

15. The method for cutting a laminate according to any one of claims 11 to 14, wherein the cutting step cuts the joint portion so that the first layer covers the second layer.

16. The method for cutting a laminate according to any one of claims 11 to 14, wherein in the cutting step, the first layer and the second layer are at a temperature lower than the melting points of the first layer and the second layer.

Images