JPWO2018096681A1 - Food packaging container and manufacturing method thereof - Google Patents

Abstract

Provided is a food packaging container which can be pierced as a plastic molded article. A flat portion (30) having a container main body opened upward and a lid covering the mouth of the container main body, the lid being flat and having a thickness t1 of 150 μm or more; 30) and the half cut part (320) for drilling formed in, and the thickness t2 of the said half cut part (320) satisfy | fills conditions (thickness t2 <= 50 micrometers of 1 micrometer <= half cut part 320) The half-cut portion (320) is a cutting blade formed with high precision on the slide while independently driving three or more axes supporting the slide of the press machine to control parallelism. Into a sheet material.

Description

  The present invention relates to a structure of a food packaging container manufactured by thermoforming a plastic sheet.

  As a food packaging, a packaging container which can be heated by a microwave as it is at home is known. The top seal type packaging container is disclosed by patent document 1, and this packaging container is comprised from the container main body which stores foodstuffs, and the cover part which covers the opening of this container main body. The lid portion is composed of a film material and a peeling label stacked on the film material so as to cover the hole formed in the film material. The label is configured to be heat shrunk, and the packaging container can be automatically punctured by heating to allow the steam to come out.

JP 2014-43276 A (paragraphs [0106], [0107], FIG. 18)

  When manufacturing the packaging container of patent document 1, since the operation | work and apparatus (labeler) which affix a label on a film material are needed, a manufacturing cost will increase. In addition, when the label deviates from the predetermined attaching position, a part of the hole may appear outside, and there is a possibility that foreign matter may enter the inside of the container from there.

  Therefore, it is possible to form a lid or a container main body that maintains a closed state (sealability) before use without depending on the label, and can partially open it (openability) during use. desired.

  Then, this invention aims at providing the packaging container for foodstuffs which can be pierced as a plastic molded article, and the manufacturing method of this packaging container for foodstuffs.

  The food packaging container of the present invention is a plastic molded article, and is provided with a flat portion formed flat and having a thickness of 150 μm or more, and a half cut portion for drilling formed on the flat portion. It is characterized in that the thickness of the half cut portion satisfies the following condition.

  The food packaging container of the present invention has a container body for containing food, and may be provided with a lid attached thereto. The lid may be removably attached or thermally attached. The flat portion is provided on at least one of the lid and the container body. The food packaging container is not limited to one configured with a single resin layer, and may be configured using a laminated material in which a film layer or the like is stacked on a base material.

  The manufacturing method of the food packaging container according to the present invention has a straightness of 0.1 / 100 L mounted on the slide while independently controlling three or more axes supporting the slide of the press machine to control parallelism. A cutting blade which is within the range is inserted into the sheet material to form the half cut portion. Here, the straightness represents the tolerance of the straightness of the cutting edge. 0.1 / 100 L indicates that the allowable error range when the blade edge extends 100 mm in a straight line is 0.1 mm, and the same error tolerance range is obtained when the blade edge extends in an arc. Represent.

  According to the present invention, unlike the packaging container of Patent Document 1, an operation of attaching a label or the like to close a hole and equipment for closing the hole are unnecessary, so that the manufacturing cost can be reduced. In addition, since the label is unnecessary, the sticking position may be shifted and the foreign matter may not intrude into the inside from the hole, and the food product can be appropriately protected from the outside of the container.

(A) is a plan view of the food packaging container according to the first embodiment of the present invention, (b) is an enlarged plan view showing an opened portion of the food packaging container of (a), (c) These are the top views which expand and show the other structural example of the half cut part of the packaging container for foodstuffs of (a). It is sectional drawing of the packaging container for foodstuffs along the AA of Fig.1 (a). (A) is the figure which expanded the cross section of the flat part which followed the BB line of FIG. 1, (b) is a figure which shows the blade which forms the half cut part of (a), (c) It is the perspective view which expanded the blade edge of (b). (A) And (b) is sectional drawing which shows the other structural example of the fitting structure of the packaging container for foodstuffs of 1st Embodiment of this invention. (A) is a schematic perspective view of the press machine which manufactures the food packaging container of 1st Embodiment of this invention, (b) is a partial front view of the press machine of (a). It is sectional drawing for demonstrating the usage method of the packaging container for foodstuffs of 1st Embodiment of this invention. It is a top view of the packaging container for foodstuffs of a 2nd embodiment of the present invention. (A) is sectional drawing of the packaging container for foodstuffs along the C-C line of FIG. 7, (b) is sectional drawing which shows the state which opened the opening part of the packaging container for foodstuffs of (a), (C) is a fragmentary sectional view showing other examples of composition of a lid of (a). It is an enlarged view of the cross section of the half cut part periphery of 2nd Embodiment of this invention. (A) And (b) is sectional drawing which shows the other structural example of the operation part of the packaging container for foodstuffs of 2nd Embodiment of this invention. It is sectional drawing for demonstrating the usage method of the packaging container for foodstuffs of 2nd Embodiment of this invention. (A) is a top view of the food packaging container of 2nd Embodiment of this invention, (b) is sectional drawing of the food packaging container along the EE line of (a), (c) These are sectional drawings which show the state which opened the opening part of the packaging container for foodstuffs of (a). It is a schematic perspective view which shows the experiment example of the packaging container for foodstuffs of this invention. (A) And (b) is the figure which expanded the cross section of the test piece used for the experiment of FIG.

1, 2, 3 Food packaging container 10, 10A, 10B Container body 11, 11B Bottom portion 12 Side portion 13, 13A Body flange portion 20, 20A, 20B Lid 200 Base material 200A Laminated material 201 Film layer 21 Top surface 22 fit Joint part 22A Horizontal part 22B Folded part 23, 23A Lid flange part 231 Outer part 24 Inclined part 25 Protrusion part 251 Top part 26 Label sticking surface 27 Operation part 271A, 271B Surface 28 Embedded part 28A Shallow bottom part 30 Flat part 310 Open part 311 Non-cutting part 315 Non-cutting part 320 Half-cutting part 321 Cutting 40 Hole 50 Press machine 51A Slide 51B Bolster bed plate 51C Type 52 shaft 53 Drive part 54 Control part 60 Cutting blade 70 Molded body 80 Food goods 90 Movable part 91 End part 100 Test pieces

First Embodiment
Fig.1 (a) is a top view which shows the packaging container 1 for foodstuffs of 1st Embodiment of this invention, FIG. 2 is sectional drawing of the packaging container 1 for foodstuffs along the AA of FIG. 1 (a). It is. The food packaging container 1 includes a container body 10 and a lid 20 removably attached to the container body 10.

  The container body 10 includes a bottom portion 11, a side surface portion 12 rising from the periphery of the bottom portion 11, and a flange portion (hereinafter referred to as a main body flange portion 13) extending outward from an upper end portion of the side surface portion 12. There is. The upper end portion of the side surface portion 12 constitutes a mouth, and the lid 20 is attached to the container main body 10 so as to close the mouth.

  The lid 20 is provided with a top surface portion 21, a fitting portion 22 provided around the top surface portion 21 and fitted into the mouth of the container body 10, and a flange portion extending outward from the fitting portion 22 to form an edge ( (Hereinafter referred to as "lid flange portion 23.)".

  The top surface 21 is formed as a circular area in plan view. In the illustrated example, the top surface portion 21 is formed to be flat throughout, but a portion protrudes upward or a portion is recessed downward to form a flat portion, a convex portion, or a recessed portion. And may be mixed and configured. Hereinafter, the area formed flat is referred to as the flat portion 30. The lid 20 is provided with an opening portion 310 so as to open a part by raising a part or pushing it to the bottom side of the container main body 10 using the flat portion 30.

  FIG. 1B is a plan view showing the unsealing portion 310 in an enlarged manner. The unsealing part 310 is provided as a circular area at the center of the flat part 30, and the unsealing part 310 is provided with a non-cutting part 311 in which a part of the periphery is connected seamlessly with the surrounding flat part. FIG. 1B illustrates the non-cut portion 311 by a two-dot chain line. Further, the remaining peripheral edge is separably connected to the surrounding flat portion via a half cut portion 320, and the half cut portion 320 is shown by a solid line in FIG. 1 (b).

  3 (a) is a cross-sectional view enlarging a part of the lid 20 along the line B-B in FIG. 1, and the half cut portion 320 has a cutting edge 61 of the cutting blade 60 shown in FIG. 3 (b). It is a portion thinner than the periphery, in which a cut 321 is formed on the way so as not to penetrate the flat portion 30 (flat portion). The thickness t1 of the flat portion 30 and the thickness t2 of the half cut portion 320 are set in the following ranges (1) and (2).

  The thickness t2 is the thickness of the connection portion remaining at the half cut portion 320, and is a value measured by the following method. The flat portion 30 including the half cut portion 320 is cut with a cutter blade, the cross section of the half cut portion 320 is observed with an optical microscope or the like, and the thickness at the cut portion is measured. Such measurement is performed at a plurality of locations of the half cut portion 320, for example, at three locations, and an average is obtained from the measured values to obtain a thickness t2 of the half cut portion 320.

  In FIG. 1 (a), the cut 321 is formed as a straight line in a C shape in plan view as the half cut portion 320, but as shown in FIG. 1 (c), a plurality of the cut 321 and the non-cut portion 315 may be alternately arranged around the opening 310. The non-cut portion 315 is provided between two adjacent cuts 321 to connect the open portion 310 and the flat portion around it, and is formed without a cut and further formed to be cuttable. There is.

  The sloped portion 24 extends outward from the peripheral edge of the top surface portion 21 and constitutes a slope which gradually descends from the flat portion 30. The fitting portion 22 includes a horizontal portion 22A extending outward from the lower end of the inclined portion 24, and a folded portion 22B extending upward from the end and fitting to the inner surface of the container body 10.

  The lid 20 is not limited to the convex shape in which the central flat portion 30 forms the highest portion as described above, and the flat portion 30 or the periphery thereof may be changed to another shape. For example, from the inner fitting type in which the slope is omitted or the lid 20 is fitted to the inside of the mouth of the container main body 10, as shown in FIG. While utilizing the structure of the outside fitting type which presses the end of the flange portion 13 or as shown in FIG. 4B, the entire inside of the lid flange portion 23 is configured as the top surface portion 21 (flat portion 30) It may be formed as a drop lid which penetrates inside from the mouth, and furthermore, an internal / external fitting type structure may be utilized, in which the lid flange portion 23 covers the main body flange portion 13 from the inside to the outside.

  The material of the container body 10 and the lid 20 is not limited, but a polyolefin resin, a polystyrene resin or a polyester resin can be used. In the food packaging container 1 of the present embodiment, a sheet material made of polystyrene, polypropylene (PP), PET, mixed resin or the like as a plastic molded product is softened by heat and further vacuum molded or pressure-formed using a mold. The food packaging container 1 is transparent, and has a haze of 15% or less, preferably 10% or less, more preferably 7% or less, as a degree of clouding. The food packaging container 1 is not limited to one having transparency, but may be opaque. In addition, the lid 20 and the container body 10 may be integrally configured via a hinge portion.

  The half cut part 320 is formed by the process which processes to a plastic molded article after said shaping | molding process. In the processing step, it is desirable to form the cut 321 as the half cut portion 320 by the cutting blade 60 and further to make the same depth over the entire length.

  As the cutting blade 60, a blade having a straightness of preferably 0.05 / 100 L or less, more preferably 0.01 / 100 L or less is used. Here, the straightness will be described with reference to FIG. 3C. The cylinder indicated by a two-dot chain line with the cutting edge 61 extending straight in design as a central axis represents the extension of the allowable range of error, and the manufactured cutting edge 61 Is placed on or in this surface. In the case of a cutting blade 60 of 0.1 / 100 L, the range is defined by extending a circular area with a diameter (φ) of 0.1 mm in a direction perpendicular to this area by a length (L) of 100 mm. Similarly, a cutting blade 60 whose cutting edge extends in an arc shape is used for forming a C-shaped half-cut portion 320 shown in a plan view of FIG. 1A. If the cutting edge 61 extends in an arc, this means that the cutting edge 61 is in a cylinder, and the range is straight by converting the cutting edge 61 that is arced in design into a straight line and taking this straight line as a central axis. Defined for the length (L). Straightness also represents the tolerance of the cutting edge parallel to the sheet to be cut. Here, a 3D scanner can be used to measure such a cutting blade.

  In the processing step, the press machine maintains the levelness of the cutting edge 61, and utilizes a 4-axis independent control high-precision processing machine as the press machine. As shown in FIG. 5A, the press machine 50 includes a slide 51A, four shafts 52 for supporting the slide 51A, four driving units 53 for driving the respective shafts 52, and a control unit 54. ing. The shaft 52 is formed of a ball screw, the drive unit 53 is formed of a servomotor, and the control unit 54 causes the servomotor to rotate the ball screw. Such driving of the shaft 52 is independently performed. The number of shafts 52 supporting the slide 51A is not limited to four. For example, the press machine 50 may have three or more shafts 52, and the control unit 54 may individually control each shaft 52 so that the slide 51A is held horizontally.

  As shown in FIG. 5B, the cutting blade 60 is attached to the slide 51A with a straightness of 0.1 / 100 L or less. The cutting blade 60 is a C-shape in which the blade edge 61 extends in an arc shape, and the tip shown in FIG. 3B is formed to be sharp at an angle θ of 30 ° to 60 °. Not only the double-edged cutting blade 60 shown in FIG. 3 (b) but a single-edged blade may be used. The cutting blade 60 is made of a tungsten carbide-cobalt based alloy as a cemented carbide. Furthermore, in the press machine 50, the bolster bed plate 51B holds the mold 51C.

With the slide 51A raised, the compact 70 is placed on the mold 51C, and the bottom dead center of the slide 51A is set to a desired position and lowered. Thus, the half-cut portion 320 is formed by the cutting blade 60 on the flat portion (flat portion 30) of the configuration of the molded body 70.

  The cutting blade 60 is preferably a blade with high accuracy in the straightness of the cutting edge, and use a cemented carbide blade manufactured by Finetech Co., Ltd. (trade name; Filey blade, linearity of the cutting edge; 0.003 / 100 L) it can. It is desirable to use a press machine 50 that can control parallelism and bottom dead center with high accuracy, and use a processing machine manufactured by EDM Corporation (trade name: ZENFormer, 4-axis independent control) it can.

The usage method of the food packaging container 1 comprised in this way is demonstrated.
With the food product placed in the food packaging container 1, the lid 20 is attached. At this time, the lid 20 is fixed by fitting the fitting portion 22 of the lid 20 to the mouth of the container main body 10. Movement of the unsealing portion 310 of the lid 20 is restricted by being connected to the peripheral flat portion via the half cut portion 320. In the state of being covered in this manner, the upper side of the food product is covered by the cover 20 without any gap.

  In the case where a food product placed in the food packaging container 1 is to be heated by a microwave oven, the half cut portion 320 is cut and the opening portion 310 is pushed into the inside of the container as shown in FIG. Steam generated in the process of heating the food product 80 exits the hole 40.

  According to the food packaging container 1 of the first embodiment, the lid 20 is provided with the half cut portion 320 in which the predetermined thickness t2 is left for drilling. This is different from the hole which penetrated the lid material of the conventional food packaging container, and since the operation | work for sticking and closing a label etc. and the installation for it are unnecessary, manufacturing cost can be reduced.

  In addition, since the label is unnecessary, the sticking position may be shifted and the foreign matter may not intrude into the inside from the hole, and the food product can be appropriately protected from the outside of the container. Furthermore, in use, the holes 40 can be partially opened simply by cutting the remaining connection portion at the half cut portion 320.

  The lid 20 can be detachably attached to the container body 10 by the fitting portion 22. Thus, the food product 80 can be repeatedly covered with the lid 20, for example, after the heated food product 80 is partially taken out.

Second Embodiment
FIG. 7 is a plan view of the food packaging container 2 according to the second embodiment of the present invention, and FIG. 8 (a) is a cross-sectional view of the food packaging container 2 taken along the line C-C of FIG. Similar to the food packaging container 1 of the first embodiment, the food packaging container 2 includes the container main body 10A and the lid 20A, but unlike the first embodiment, the lid 20A is a fitting portion. Not equipped with 22. The lid 20A is configured to be fixed by overlapping the container body 10A and the peripheral portion. The same reference numerals are used for the same or similar configurations as the configuration of the food packaging container 1 of the first embodiment, and the description thereof will be omitted.

  The flanges of the container body 10A and the lid 20A (hereinafter referred to as the body flange 13A and the lid flange 23A) are formed in flat surfaces extending outward so that they can be superimposed on each other. The lid 20A is attached to the container main body 10A by thermal bonding with the sealing machine in the overlapped state. The width w of the main body flange portion 13A and the lid flange portion 23A is preferably 3 mm or more.

  The lid 20A and the container body 10A may be made of a laminated material made of a plurality of layers in addition to molding and manufacturing the base material 200 made of a single layer shown in FIG. . For example, as shown in FIG. 9, a laminated material 200A in which the film layer 201 is laminated on the inside of the base material 200 may be used. As the film layer 201, functions such as a gas barrier layer, a moisture proof layer, and a heat seal layer can be added to the base 200. When the laminate is composed of the base material 200 of a polyolefin resin and a plurality of layers stacked thereon, the weight of the polyolefin resin is preferably 70% or more of the weight of the resin in the entire laminate.

  In the laminated material 200A of the illustrated example, the cut 321 of the half cut portion 320 reaches the inside of the film layer 201, and the thickness t2 of the half cut portion 320 is the thickness of the remaining portion of the film layer 201. Is set in the range of Although illustration is omitted, the half cut portion 320 may be configured without inserting the cut 321 in the film layer 201, or the cut 321 cuts the film layer 201 from the inside of the container and connects only the base 200 Alternatively, the half cut portion 320 may be configured. Further, also in the case where the laminated material 200A is configured to sandwich the gas barrier layer or the like, the cuts 321 may cut the gas barrier layer or the like.

  Further, as shown in FIG. 8A, the lid 20A is provided with a protrusion 25 which protrudes upward from the periphery of the central flat portion 30. The projecting portion 25 is provided around the flat portion 30 except for the front side, and these are connected to surround the flat portion 30. The tops 251 constituting the highest portions of the protrusions 25 are arranged at the same height, and the slopes respectively falling outward from the tops extend to the lid flange portion 23A. A label sticking surface 26 is formed on the front side of the flat portion 30. In addition, the lid 20A may be configured without the label attaching surface 26, or the protruding portion 25 may be provided so as to surround the entire flat portion 30.

  An operation portion 27 for facilitating the hole formation at the time of opening is provided integrally with the region inside the half cut portion 320, that is, the flat portion 30. The operation portion 27 protrudes upward, and its height h is set so as not to exceed the height H of the protrusion 25. The height h from the flat portion 30 of the operation unit 27 is preferably 5 mm or more. Further, the operation unit 27 includes a pair of opposing surfaces 271A and 271B, and is configured to be able to be picked.

  In addition, the lid 20A includes an embedded portion 28 which is recessed toward the bottom of the container main body 10A in the vicinity of the opening portion 310. The unsealing part 310 is configured to be able to rotate about the non-cutting part 311 shown by a two-dot chain line in FIG. It is provided in the direction to rotate 310, and the operation part 27 can be inserted. The embedded portion 28 is configured by selecting the size and the depth so that the operation portion 27 can be fitted. As shown in FIG. 8B, the embedded portion 28 can maintain the state in which the operating portion 27 is rotated by 180 degrees after the operating portion 27 is pinched and the hole 40 is opened.

  FIG. 8C is a cross-sectional view showing a modification of the structure for fixing the operation unit 27 and shows a state in which the operation unit 27 is rotated by 180 degrees. The lid 20A may be configured such that a shallow bottom portion 28A for containing the peripheral region of the unsealing portion 310 is provided adjacent to the embedded portion 28 and the operation portion 27 is accommodated in the embedded portion 28 and the shallow bottom portion 28A.

  The operation unit 27 is not limited to a configuration that functions as a knob, and, for example, as shown in FIGS. 10A and 10B, the operation unit 27 is formed in a button shape so that the half cut portion 320 can be easily cut by pushing. May be

  Similarly to the first embodiment, the container body 10A and the lid 20A according to the second embodiment are formed into a sheet material made of resin, and then half cut into the flat portion 30 using the press machine 50 provided with the cutting blade 60. Portions 320 may be formed and manufactured. The projection 25, the operation part 27, the embedded part 28 and the like are integrally formed with the flat part 30 during molding, but the projection 25, the operation part 27, the embedded part 28 and the like are omitted to use for food The packaging container 2 may be manufactured.

  When the container body 10A and the lid 20A are made of a laminated material having the base material 200 and a sealing layer for thermal bonding, and the laminated material is mainly made of polypropylene, the outermost layer provided on the outermost side It is desirable that the difference (T1-T2) between the melting point T1 of the above and the melting point T2 of the seal layer be 10.degree.

The usage method of the food packaging container 2 comprised in this way is demonstrated.
The lid 20A is attached while the food is placed in the container body 10A. At this time, the lid 20A is fixed by joining the main body flange portion 13A and the lid flange portion 23A with a sealing machine in a state where the main body flange portion 13A and the lid flange portion 23A are superimposed. Movement of the unsealing portion 310 of the lid 20A is restricted by being connected to the peripheral flat portion through the half cut portion 320. In the state of being covered in this manner, the upper side of the food product is covered by the cover 20A without any gap.

  When the food placed in the food packaging container 2 is heated by the microwave, the lid 20A is attached to the container body 10A and placed on the table of the microwave in a sealed state. As the food is heated, the pressure inside the food packaging container 2 gradually increases. This pressure acts on the weakly configured half cut portion 320 by inserting the cut 321 in the configuration of the food packaging container 2, and the remaining connection portion is cut. As a result, as shown in FIG. 11, the unsealing unit 310 is pushed by the steam from the initial position indicated by the broken line to the high position indicated by the solid line and stands up. Holes 40 can be opened during heating to allow the steam to escape. Before heating, as in the first embodiment, the half cut portion 320 may be cut and the hole 40 may be opened.

  As described above, according to the food packaging container 2, the heat sealing of the main body flange portion 13 </ b> A and the lid flange portion 23 </ b> A can improve sealing performance as compared with the first embodiment. Furthermore, since the gas barrier layer can be applied to the food packaging container 2, the sealing performance can be further enhanced.

  By surrounding the flat portion 30 and the unsealing portion 310 with the protruding portion 25, it is possible to reduce an unnecessary force acting on the operation portion 27 or the like. Thereby, the sealed state of the food packaging container 2 can be ensured.

Third Embodiment
FIG. 12 shows a food packaging container 3 according to a third embodiment of the present invention, in which (a) is a plan view and (b) a sectional view taken along the line E-E in (a). Similar to the food packaging container 1 of the first embodiment, the food packaging container 3 includes the container body 10B and the lid 20B, but unlike the first embodiment, the unsealing portion 310 is the container body 10B. Provided in The container main body 10B is configured as a flat portion 30 while the central region of the bottom portion 11B is provided at a position higher than the region of the landing edge. Furthermore, a half cut portion 320 is formed on the flat portion 30 of the bottom portion 11B. In the bottom portion 11B, the central region is configured to have the thickness t1 of the above (1), and the half cut portion 320 is formed as a portion where the thickness t2 of the above (2) is left. The same code | symbol is used for the same or similar structure as the packaging container 1 for foodstuffs of said 1st Embodiment, and those description is abbreviate | omitted.

  According to the food packaging container 3, the half cut portion 320 provided in the bottom portion 11B is cut, and the opening portion 310 is turned around as shown in FIG. 12 (c) to partially open the hole 40 in the container body 10B. Can.

Hereinafter, the experiment example of the opening part 310 provided in the packaging containers 1-3 for foodstuffs is demonstrated.
(Measurement condition)
As shown in FIG. 13, using the test piece 100 provided with the C-shaped half-cut portion 320, the degree of opening (openability) and degree of closing (sealing) of the unsealing portion 310 defined by the half-cut portion 320 I confirmed. The test piece 100 was manufactured by forming the half cut portion 320 on a rectangular base material 200 made of plastic with a 4-axis independent control press machine. In this production, the cutting blade 60 utilizes a cemented carbide blade (FINETECH Co., Ltd .; trade name; Fily blade, straightness of the cutting edge; 0.003 / 100 L), and the press machine 50 is a processing machine (discharge Co., Ltd.) Precision processing laboratory, trade name: ZENFormer, 4 axis independent control) was used.

  In each experiment, when the thickness t2 of the half cut portion 320, the thickness t1 of the base material 200, or the film layer 201 is stacked on the half cut portion 320, the entire thickness is t1, the insertion direction of the blade, and the opening portion 310 , Called opening method.) Is changing.

  The thickness t2 of the half cut portion 320 is measured by cutting the test piece 100 and using an optical microscope (manufactured by KEYENCE; VHX-2000) and a lens (manufactured by KEYENCE; VH-Z100UR) as a cross section of the half cut portion 320 The thickness was observed at a magnification of 400 times, and the thickness of the cut portion was measured. The thickness was measured at each of three places of the half cut portion 320, and an average was obtained from each value to handle the thickness t2 of the half cut portion 320.

  The half cut part 320 is a form which lacks a part of circumference | surroundings of radius 10 mm in planar view, continues continuously, and the full length is set to 47 mm. The end 91 (diameter φ 12 mm) of the movable part 90 is compressed to a flat area (open part 310) inside the half cut part 320 by a measuring device (Instron, electromechanical testing systems, model number 5565) at a compression speed of 200 mm / Press down with min. Then, the measurement is ended when the half cut portion 320 is cut. The measuring device measured the maximum value of the peak at that time as the opening strength (hereinafter referred to as opening strength) [kg].

(Experimental example 1)
The base 200 is made of polypropylene and the outside of the container has a higher melting point than the inside of the container, and the overall thickness t1 is 300 μm. The half cut part 320 is formed by putting the cutting blade 60 from the outside of the container as shown in FIG. 14A, and the thickness t2 is 15 μm. As an opening method, as a "pull" for moving the opening part 310 to the outside of the container, pressing of the opening part 310 by the movable part 90 from the inside of the container was performed.
In Experimental Example 1, the opening strength was 1.7 kg. The opening part 310 whose movement is restricted by the half cut part 320 can be opened easily, and the state where the movement is restricted by the half cut part 320 can be stably maintained. The comprehensive evaluation of Experimental Example 1 is good (o).

(Experimental example 2)
Experimental Example 2 uses the same test piece 100 as Experimental Example 1, but the opening method is different. In Experimental Example 2, as the opening method, as a "push" for moving the opening part 310 to the inside of the container, pressing of the opening part 310 by the movable part 90 from the outside of the container was performed.
The opening strength of Experimental Example 2 was 1.7 kg. The opening part 310 whose movement is restricted by the half cut part 320 can be opened easily, and the state where the movement is restricted by the half cut part 320 can be stably maintained. The comprehensive evaluation of Experimental Example 2 is good (o).
From Experimental Example 1 and Experimental Example 2, it was found that there was no influence on the handling due to the difference in the opening method.

(Experimental example 3, 4)
Although the experimental examples 3 and 4 use the same base material 200 as the experimental example 1, the arrangement of the half cut portion 320 is different. In the experimental examples 3 and 4, the half-cut portion 320 is formed by inserting the cutting blade 60 from the inside of the container as shown in FIG. 14 (b), and the thickness t2 is 15 μm same as the experimental examples 1 and 2. It is. The opening method of the experimental example 3 is "pull", and the opening method of the experimental example 4 is "push".
The opening strength of each of Experimental Example 3 and Experimental Example 4 was 1.7 kg. The opening portion 310 whose movement is restricted by the half cut portion 320 can be easily opened, and the half cut portion 320 can stably maintain the state where the movement is restricted. The comprehensive evaluations of Experimental Example 3 and Experimental Example 4 are good (o), respectively.
From Experimental Example 1 to Experimental Example 4, it was found that there is no influence on the handling depending on whether the surface on which the half cut portion 320 is provided is the front or the back.

(Experimental example 5)
Although the example 5 of an experiment uses the same base material 200 as the example 1 of an experiment, the thickness t2 of the half cut part 320 differs. In Experimental Example 5, the thickness t2 is 5 μm.
The opening strength of Experimental Example 5 was 0.8 kg. The unsealing unit 310 whose movement is restricted by the half cut unit 320 can be opened more easily as compared with Experimental Example 1, but the function of fixing the unsealing unit 310 by the half cut unit 320 is lowered. The comprehensive evaluation of Experimental Example 5 is acceptable (Δ).
From Experimental Example 5, it was found that although the remaining thickness dimension in the incision was reduced, there was no significant effect when used for a food packaging container.

(Experimental example 6)
Experimental Example 6 uses the same base material 200 as Experimental Example 1, but the thickness t2 of the half cut portion 320 is different. In Experimental Example 6, the thickness t2 is 20 μm. The surface provided with the half cut portion 320 and the method of opening the same are the same as in Experimental Example 1.
The opening strength of Experimental Example 6 was 2.3 kg. Compared to Experimental Example 1, although it is necessary to increase the force in the operation of the unsealing portion 310 when making a hole, the function of fixing the unsealing portion 310 by the half cut portion 320 is strengthened. The comprehensive evaluation of Experimental Example 6 is acceptable (Δ).
From Experimental Example 6, it was found that although the remaining thickness dimension at the cut was increased, there was no significant effect when used for a food packaging container.

(Experimental example 7)
Experimental Example 7 utilized a base material 200 different from Experimental Example 1. The base material 200 of Experimental Example 7 is the same as the experimental example 1 as a material, but the total thickness t1 is 250 μm. The surface on which the half-cut portion 320 is provided, the thickness t2 thereof, and the opening method are the same as those of Experimental Example 1.
The opening strength of Experimental Example 7 was 1.7 kg. The opening part 310 whose movement is restricted by the half cut part 320 can be opened easily, and the state where the movement is restricted by the half cut part 320 can be stably maintained. The comprehensive evaluation of Experimental Example 7 is good (o).
From Experimental Example 1 and Experimental Example 7, it was found that the difference in the overall thickness t1 of the substrate 200 has no influence on the handling.

(Experimental example 8)
Experimental Example 8 utilized a base material 200 different from Experimental Example 1. The base material 200 of Experimental Example 8 utilized a laminated material in which a low density polyethylene film layer (50 μm) was provided on the inside of polypropylene (250 μm) via an adhesive. The thickness t2 of the half cut portion 320 is 30 μm. The surface provided with the half cut portion 320 and the method of opening the same are the same as in Experimental Example 1.
The opening strength of Experimental Example 8 was 3.2 kg. Compared to Experimental Example 1, although it is necessary to increase the force in the operation of the unsealing portion 310 when making a hole, the function of fixing the unsealing portion 310 by the half cut portion 320 is strengthened. The comprehensive evaluation of Experimental Example 8 is acceptable (Δ).
From Experimental Example 8, it was found that although the laminated material was used and the remaining thickness dimension at the incision 321 was increased, there was no significant effect when used for a food packaging container.

(Experimental example 9)
Experimental Example 9 utilized a base material 200 different from Experimental Example 1. The base material 200 of Experimental example 9 is comprised by A-PET, and thickness t1 is 300 micrometers. The thickness t2 of the half cut portion 320, the surface on which the half cut portion 320 is provided, and the unsealing method are the same as in the first experimental example.
The opening strength of Experimental Example 9 was 2.5 kg. Compared to Experimental Example 1, although it is necessary to increase the force in the operation of the unsealing portion 310 when making a hole, the function of fixing the unsealing portion 310 by the half cut portion 320 is strengthened. The comprehensive evaluation of Experimental Example 9 is good (o).
From Experimental Example 9, it was found that the difference in the material constituting the base material 200 had no significant effect when used in a food packaging container.

(Comparative example 1)
The comparative example 1 uses the same base material 200 as the experimental example 1, but the thickness t2 of the half cut portion 320 is different. In Comparative Example 1, the thickness t2 is 0.5 μm.
The opening strength of Comparative Example 1 was 0.1 kg. Although it can open very easily compared with Experimental example 1, the function to which the opening part 310 by the half cut part 320 is fixed is inferior. The comprehensive evaluation of Comparative Example 1 is not possible (NG).
From Comparative Example 1, the remaining thickness dimension at the notch 321 is required to be 1 μm or more.

(Comparative example 2)
The comparative example 2 uses the same base material 200 as the experimental example 1, but the thickness t2 of the half cut portion 320 is different. In Comparative Example 2, the thickness t2 is 55 μm.
The opening strength of Comparative Example 2 was 5.2 kg. Compared to Experimental Example 1, a large force is required to operate the unsealing portion 310 when making a hole. The comprehensive evaluation of Comparative Example 2 is not possible (NG).
From Comparative Example 2, it is desirable that the remaining thickness dimension in the notch 321 be 50 μm or less.

  Table 1 below respectively shows the configuration and thicknesses t1 and t2 of the base material in the above-mentioned experimental example, the insertion direction of the blade, and the opening method.

  Table 2 below shows the opening strength, the opening property, the sealing property, and the overall evaluation of Experimental Examples 1 to 9 and Comparative Examples 1 and 2.

(Experimental result)
From the above Experimental Examples 1 to 9 and Comparative Examples 1 to 2, the opening property and the sealing property of the opening part 310 are the half of the configuration (single layer, laminated material) of the flat part 30 and the thickness t1. It depends on the thickness t2 of the cut portion 320. The thickness t2 of the half cut portion 320 is 1 μm or more and 50 μm or less of the above (2), preferably in the range of the following (3), more preferably (4).

  The present invention can be configured without being limited to the above description and illustrated examples. For example, the size and shape of the unsealing portion and the number thereof are not limited to one, and a plurality may be provided.

The material which constitutes the food packaging container is not limited to the above, and a laminated material may be used in which a resin sheet having a hole and a resin film provided with the half cut portion 320 overlap each other. In this laminated material, the area surrounded by the half cut portion and the area of the hole are aligned in the thickness direction. The laminated material is molded to manufacture a lid or a container body, and the connecting portion remaining at the half cut portion 320 is cut at the time of use, for example, the opening portion 310 of a film is pushed into a hole of a sheet to be opened it can.

Claims (7)

Plastic molded products,
A flat portion formed to have a thickness of 150 μm or more and a half cut portion for drilling formed on the flat portion;
A packaging container for food, wherein the thickness of the half cut portion satisfies the following condition (1).

A container body having an open mouth at the top, and a lid covering the mouth of the container body,
The said flat part is formed in the said cover body, The packaging container for foodstuffs of Claim 1 characterized by the above-mentioned.   The food packaging container according to claim 2, wherein the lid can be detachably attached to the container body. The container body and the lid each include a flange portion that can be overlapped.
Further, the lid body is formed of a laminated material having the outermost layer provided with the outermost layer having a melting point of T1 and the sealing layer having a melting point of T2 for thermal bonding with the container main body,
The food packaging container according to claim 2, wherein the melting point difference (T1-T2) is 10 ° C or more and less than 50 ° C.   The food packaging container according to any one of claims 1 to 4, further comprising a gas barrier layer. The area for drilling is surrounded by the above half cut section,
The food packaging container according to claim 1, further comprising an operation unit for forming a hole integrally with the flat portion in this area. It is a plastic molded article provided with a flat portion having a thickness of 150 μm or more and a half cut portion for drilling formed on the flat portion,
A method for producing a food packaging container, wherein the thickness of the half cut portion satisfies the following condition (2),
Insert a cutting blade with a straightness of 0.1 / 100 L or less into the sheet material while controlling the parallelism by independently driving three or more axes supporting the slide of the press machine, The manufacturing method of the packaging container for foodstuffs characterized by forming the said half cut part.

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