JP2009255976A - Packaging container and its manufacturing method and apparatus - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a packaging container with stable easy unsealability and sealability, in the manufacturing process of which time and labor, and cost, are reduced, and also to provide a manufacturing method and apparatus for the container. <P>SOLUTION: The packaging container 100 is equipped with a container body 200 having a nearly round shape in the plane face, in a hollow part 210 of which contents P are stored, and in the container body 200, a lid material 300 is sealed by heat to a flange part 230 provided at the perimeter of the opening part in order to close the opening part formed in a nearly round shape in the plane face at the center part. The heat seal between the flange part 230 and the lid material 300 is performed in a circular seal part 240. The container body 200 is formed of a multi-layer sheet 250 composed of a seal layer 251, an adjacent layer 252 and a main material layer 253. The flange part 230 is formed in such a way that the thickness becomes gradually thinner from the outer edge 231 to the inner edge 232. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a packaging container, a manufacturing method thereof, and a manufacturing apparatus.

Conventionally, as a packaging form for food or the like, there is a packaging container in which, after storing or filling the food or the like, a flange portion provided on the periphery of the opening of the container body and a film-like lid material are heat sealed and hermetically packaged. is there. In this packaging container, the lid material is peeled from the container body when taking out the stored food or the like.
In such a packaging container, sealability before opening is important, but easy-openability at the time of opening is also required. In view of this, a technique is generally known in which the sealing strength of the sealing layer of the container body is controlled by changing the resin material and the interface between the lid material and the container body is peeled off.

For example, Patent Document 1 discloses a simple peel container in which a cut is provided in the interior of the flange portion on the container opening side.
Further, Patent Document 2 describes a configuration in which the innermost layer at the inflection point from the side wall of the container body to the flange portion is thinned and the peel strength of the innermost layer is adjusted.
Furthermore, Patent Document 3 describes a form in which a missing portion of the seal layer is locally formed at the boundary position between the container side surface of the container main body and the flange inner edge to adjust the peel strength.

Japanese Patent Laid-Open No. 62-251363 Japanese Patent Publication No. 5-79587 JP-A-7-309368

However, the method for controlling the seal strength is easily affected by the seal conditions and tends to cause variations in strength.
Moreover, in patent document 1, since it takes an effort and time in order to form a notch part, there exists a problem that a burden is imposed on a cost function side. In addition, there is a problem that it is difficult to maintain the sealability if the distance between the seal part and the cut part of the container is not more than a certain distance, and the position control of the seal part is important, so the technical difficulty is high and easy It will be difficult to produce.
Furthermore, in patent document 2 and patent document 3, since the thickness of the innermost layer of a container becomes unstable or a missing part cannot be formed stably, it is said that it becomes difficult to open or sealability is impaired. There's a problem.

  An object of the present invention is to provide a packaging container having a stable easy-opening property and a sealing property and capable of reducing labor and cost in a manufacturing process, a manufacturing method thereof, and a manufacturing apparatus.

  The packaging container of the present invention is a packaging container provided with a container body having a flange portion formed at the periphery of the opening, and a lid member that closes the opening and is sealed between the flange by a seal portion. And at least one of the container main body and the lid member includes at least two layers of a seal layer and a base material layer, and the seal layer is a thin-walled portion or a missing portion on the inner peripheral side of the flange portion. The flange portion is characterized in that the thickness of the inner edge portion is 20% or more and 98% or less with respect to the thickness of the outer edge portion.

In this invention, the inner edge portion of the flange portion has a thickness in the range of 20% to 98% with respect to the thickness of the outer edge portion. That is, the flange portion is thinly formed from the outer edge portion to the inner edge portion. Thereby, a thin-walled portion or a missing portion is formed in the seal layer in the vicinity of the inner edge portion of the flange portion.
Therefore, when opening the packaging container, it peels between the sealing layer and the layer adjacent to the sealing layer, and the sealing layer is separated at the thin-walled portion of the sealing layer at the breakage or missing portion. Opened. Thus, since the thin layer part or the missing part is provided in the seal layer, it can be easily opened.
In addition, when the thickness of the inner edge part of a flange part is less than 20% with respect to the thickness of an outer edge part, since the thickness of an inner edge part is too thin, there exists a possibility that the rigidity as a container may be insufficient. Further, if the thickness of the inner edge portion of the flange portion exceeds 98% with respect to the thickness of the outer edge portion, there is almost no difference in the thickness between the inner edge portion and the outer edge portion of the flange portion.
Therefore, when the thickness of the inner edge portion of the flange portion is 20% or more and 98% or less with respect to the thickness of the outer edge portion, a thin-walled portion or a missing portion is formed at the inner edge portion of the flange portion, and excellent easy-openability. And a sealing container having sealing properties can be provided.
Further, since the flange portion is formed so as to become thinner toward the inner edge portion, it is not necessary to control the position of the seal portion when sealing the lid member and the container body. That is, it is possible to easily manufacture a container that achieves both easy opening and high sealing.

  The packaging container of the present invention is a packaging container provided with a container body having a flange portion formed at the periphery of the opening, and a lid member that closes the opening and is sealed between the flange by a seal portion. The flange portion includes a flat flat portion on which a seal portion is formed, and an extending portion that extends to an outer peripheral edge of the flat portion, and includes the container body and the lid member. At least one of them includes at least two layers of a seal layer and a base material layer, and the seal layer has a thin part or a missing part on at least one of the outer peripheral side and the inner peripheral side of the flat part, On the other hand, it has an easily separating means that can be easily separated, and the flat part has a thickness of 20% or more and 98% or less on the side having the thin part or missing part with respect to the thickness of the central part. And

In this invention, the flange part is comprised by the planar flat part and the extension part extended from the outer periphery of the flat part. The extending portion is formed in a skirt shape or a curl shape, for example. The skirt shape is, for example, a shape extending obliquely downward from the edge of the flat portion. The curled shape is, for example, a shape formed in a curved surface continuously from the vicinity of the edge of the flat portion toward the wall portion forming the container body.
Further, at least one of the outer peripheral side and the inner peripheral side of the seal layer has a thinned portion or a missing missing portion, and the thickness of the thinned portion or missing portion is 20% or more with respect to the thickness of the central portion. It is formed in the range of 98% or less. Here, the outer peripheral side indicates the vicinity of the outer edge of the flange portion, the inner peripheral side indicates the vicinity of the inner edge of the flange portion, and the central portion is a portion located between the inner edge portion and the outer edge portion of the flange portion. The other sealing layer on the outer peripheral side and the inner peripheral side of the flange portion is provided with easy separation means that can be easily separated. The easy separation means is not particularly limited as long as the lid member sealed by the seal portion and the container main body are easily separated. For example, it is good also as a structure which provided the notch part in the sealing layer.
Therefore, when opening the packaging container, the sealing layer easily breaks or separates on the outer peripheral side of the flange portion and becomes a peeling start position, and the sealing layer easily separates on the inner peripheral side of the flange portion and the peeling end position. Become. As described above, at least one of the outer peripheral side and the inner peripheral side of the flange portion is provided with the thin-walled portion or the missing portion, and the other is provided with the easy separation means, so that the packaging container can be easily opened.

  In the packaging container of the present invention, the easy separation means is a thin part or a missing part, and the flat part has a thickness of 20% or more and 98% or less on the side having the easy separation means with respect to the thickness of the central part. It is preferable that

The present invention provides a packaging container having a shape in which the above-described extending portion is extended to the flange portion, and has a thin-walled portion or a missing portion on at least one of the outer peripheral side and the inner peripheral side of the flange portion, and is provided on the other side. The easy separation means is a thin portion or a missing portion. The thickness of the side having the easy separation means is formed in the range of 20% to 98% with respect to the thickness of the central portion. That is, the inner peripheral side and the outer peripheral side of the flange portion are missing or thinned. Therefore, when opening the packaging container, the outer peripheral side of the flange portion becomes the peeling start position of the seal layer, and the inner peripheral side of the flange portion becomes the peeling end position and peels between the seal layer and the layer adjacent to the seal layer. The packaging container is opened by separating the sealing layer when the thin portion of the sealing layer is broken or missing. Thus, since the thin part or the missing part is provided on the outer peripheral side and the inner peripheral side of the flange part, it can be easily opened.
The thickness of the easy separation means is 20% or more and 98% or less with respect to the thickness of the central portion, and when the easy separation means is less than 20% with respect to the thickness of the central portion, the thickness of the easy separation means is too thin. There is a risk that the rigidity of the container will be insufficient. Further, if the thickness of the easy separation means exceeds 98% with respect to the thickness of the central portion, there is almost no difference between the thickness of the easy separation means and the central portion, so that a thin portion or a missing portion is not formed. That is, when the thickness of the easy separation means is 20% or more and 98% or less with respect to the thickness of the central portion, a thin-walled portion or a missing portion is formed in the easy separation means, and excellent easy-openability and sealing performance Can be provided. In addition, the thickness of the inner peripheral side and outer peripheral side of a flange part may be the same thickness, and may differ.

  In the packaging container of the present invention, the melt index (MI) value of the seal layer is larger than the MI value of the adjacent layer adjacent to the seal layer, and the MI value of the seal layer and the layer adjacent to the seal layer are The difference from the MI value is preferably 3 g / 10 min or more.

  Here, when a thin portion is provided in the seal layer, the thin portion is opened by being broken at the time of opening. At this time, if the difference between the MI value of the seal layer and the MI value of the adjacent layer is less than 3 g / 10 min, the thin-walled portion is difficult to break, so the seal layer after the breakage becomes conspicuous and the appearance is beautiful. Absent. Therefore, by setting the difference between the MI value of the sealing layer and the MI value of the adjacent layer to 3 g / 10 min or more, a packaging container having a beautiful opening can be provided.

  The manufacturing method of the packaging container of this invention implements the container shaping | molding process which provides the gradient to the said flange part using the flange presser which has the pressing surface which presses down the said flange part, and the metal mold | die which shape | molds the said container main body. It is characterized by that.

  According to this invention, the procedure is the same as the conventional container forming process, but when forming a container using a mold and a flange presser, the stretching condition of the material sheet at the time of molding and the timing of pressing with the flange presser are adjusted. By doing so, a gradient can be provided in the flange portion. Therefore, a packaging container having a target shape can be easily formed without changing the conventional procedure, and labor and manufacturing costs can be reduced.

The method of manufacturing a packaging container of the present invention, the flange pressing is preferably to press the flange portion is 1.5 kg / cm ² or more 20 kg / cm ² or less pressure.

If the pressure of the flange pressing is less than 1.5 kg / cm ² , a thin portion or a missing portion cannot be formed on the inner edge side of the flange portion. On the other hand, if the pressure of the flange presser exceeds 20 kg / cm ² , the seal layer may be thinned or missing, and the adjacent layer may be affected.
Therefore, by setting the pressure of the flange pressing in the range of 1.5 kg / cm ² or more and 20 kg / cm ² or less, a thin-walled portion or a missing portion can be formed in the flange portion, and easy-openability can be realized. .

In the method for manufacturing a packaging container according to the present invention, it is preferable that the flange pressing has a gradient on the pressing surface.
Specifically, a slope is provided on the pressing surface of the flange pressing with respect to the surface of the flat portion of the mold. Then, by pressing the multilayer sheet with the pressing surface having this gradient, the flange portion (seal layer) having a gradient can be formed with different thicknesses on the outer peripheral side and the inner peripheral side of the flange portion.
According to this invention, although the procedure is the same as the conventional container forming process, the container forming process is carried out using the flange presser having a pressing surface having a shape different from the conventional one. Therefore, a packaging container having a target shape can be easily formed without changing the conventional procedure, and labor and manufacturing costs can be reduced.

  In the method for manufacturing a packaging container according to the present invention, it is preferable that the flange holder is provided with a gradient of 0.1 ° to 25 ° on the holding surface.

According to this invention, the gradient of the pressing surface of the flange pressing member is set to 0.1 ° or more and 25 ° or less to form a gradient in the flange portion, and a thin wall is formed on at least one of the outer peripheral side and the inner peripheral side of the flange portion. A portion or a missing portion can be easily formed.
When the slope of the pressing surface is less than 0.1 °, the flange cannot be formed on the flange portion. Therefore, a thin part or a missing part cannot be formed on at least one of the outer peripheral side and the inner peripheral side of the flange part. Moreover, when the slope of the pressing surface exceeds 25 °, there is a possibility that a missing portion cannot be formed by winding a seal layer or the like when the multilayer sheet is pressed with a flange pressing.
A more preferable range of the slope of the pressing surface is 3 ° to 15 °, and a more preferable range is 6 ° to 10 °.

  In the manufacturing method of the packaging container of this invention, it is preferable that the said flange pressing and the said metal mold | die hold | suppress the said flange part at the temperature of 10 to 160 degreeC.

Molding is possible even when the temperature of the flange presser and the mold is lower than 10 ° C., but the higher the temperature, the more stable and thinner the wall can be made. However, if the temperature exceeds 160 ° C., the temperature becomes close to the melting point of the seal layer, so that molding becomes unstable.
Therefore, by setting the temperature of the flange retainer and the mold to be in the range of 10 ° C. or higher and 160 ° C. or lower, it is possible to stably form a thin portion or a missing portion on the inner edge portion of the flange portion. A more preferable range of the temperature of the flange presser and the mold is 100 ° C. or more and 120 ° C. or less.

  The apparatus for manufacturing a packaging container according to the present invention includes a mold having a concave portion for forming the container body and a flat portion for forming the flange portion, and a flange presser having a gradient with respect to the flat portion. It is characterized by.

  According to the present invention, by pressing the multilayer sheet with the flat portion of the mold and the flange presser, the flange portion having the above-described shape can be formed, and the same effects as described above can be achieved.

In the packaging container manufacturing apparatus of the present invention, it is preferable that the gradient is provided in a range of 0.1 ° or more and 25 ° or less on a holding surface that holds the flange portion.
According to the present invention, the flange pressing member is provided with a gradient of 0.1 ° or more and 25 ° or less, so that the same effect as described above can be obtained.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
[First embodiment]
FIG. 1 is a perspective view showing a sealed state of the packaging container according to the first embodiment. FIG. 2 is a perspective view showing a state where a part of the packaging container according to the first embodiment is opened. 3 is a cross-sectional view taken along the line III-III in FIG. 1, and FIG. 4 is a cross-sectional view taken along the line IV-IV in FIG.

[Composition of packaging container]
In FIG. 1, the packaging container 100 includes a planar substantially circular container main body 200 in which the contents P are stored in the recess 210, and the container main body 200 has an opening 220 formed in a substantially circular planar shape at the center thereof. In order to close the cover, the lid member 300 is heat-sealed to a flange portion 230 disposed on the periphery of the opening 220. The heat seal between the flange portion 230 and the lid member 300 is performed by an annular seal portion 240.
As shown in FIGS. 1 and 2, the packaging container 100 grasps a grip part 310 from which a part of the cover material 300 protrudes, peels the cover material 300 sealed by the seal part 240 from the flange part 230, and opens it. It is what is done.

As shown in FIGS. 3 and 4, the container body 200 is formed of a multilayer sheet 250 including a sealing layer 251, an adjacent layer 252, and a base material layer 253.
The seal layer 251 is the innermost layer of the container main body 200, and the seal surface 251 </ b> A on the lid member 300 side is sealed by the lid member 300 at the flange portion 230 to form the seal portion 240. Note that the lid member 300 is not heat-sealed in the vicinity of the inner edge portion 232 of the flange portion 230.
The flange portion 230 is formed so that its thickness gradually decreases from the outer edge portion 231 to the inner edge portion 232. When the thickness Y of the inner edge portion 232 of the flange portion 230 and the thickness of the outer edge portion 231 are X, the flange portion 230 is formed so that the value of Y / X is in the range of 20% to 98%.
Since the flange portion 230 is formed so as to become thinner toward the inner edge portion 232, the lid member 300 is not sealed in the vicinity of the inner edge portion 232 of the flange portion 230 when the lid member 300 and the container body 200 are sealed. At this time, the position control of the seal portion 240 is not required. That is, it is possible to easily manufacture a container that achieves both easy opening and high sealing.

  In the present embodiment, an annular missing portion 251 </ b> B in which the seal layer 251 is missing is formed along the inner edge 232 of the flange portion 230. Thereby, the thickness of the inner edge part 232 of the flange part 230 is Y / X = 50% with respect to the outer edge part 231 of the flange part 230, for example.

  The recess 210 includes a bottom 211 that forms the bottom of the container body 200, a wall 212 that is formed by being raised from the bottom 211, a step 213 that is formed on the opening 220 side of the wall 212, It has. The step portion 213 has an outer periphery that protrudes outward from the outer periphery of the wall portion 212.

Next, each layer will be described in detail.
The seal layer 251 is provided to be peelable from the adjacent layer 252 while being sealed with the lid member 300. The peel strength between the sealing layer 251 and the adjacent layer 252 is preferably set within a range of 0.5 kg / 15 mm to 2.5 kg / 15 mm. If the peel strength between the seal layer 251 and the adjacent layer 252 is less than 0.5 kg / 15 mm, the sealing performance may be impaired. If the peel strength exceeds 2.5 kg / 15 mm, the seal layer 251 is removed from the adjacent layer 252. Difficult to peel off and difficult to open. A preferable range of the peel strength is 0.5 kg / 15 mm or more and 1.3 kg / 15 mm or less.

The thickness of the seal layer 251 before the multilayer sheet 250 is formed on the container body 200 is preferably in the range of 10 μm to 100 μm, and can be appropriately prepared depending on the size and use of the container. When the thickness of the sealing layer 251 before molding is less than 10 μm, the sealing layer 251 is not stable when sealed with the lid member 300, so that it is difficult to peel from the adjacent layer 252. On the other hand, if the thickness of the seal layer 251 exceeds 100 μm, it is not practical because it becomes thicker than necessary.
The resin constituting the sealing layer 251 is not particularly limited as long as it is a material having heat sealing properties. Examples thereof include polypropylene resins such as homopolypropylene (HPP), random polypropylene (RPP), and block polypropylene (BPP), polyethylene resins such as high-density polyethylene (HDPE), and amorphous polyethylene terephthalate.

The adjacent layer 252 is provided so as to be peelable from the seal layer 251.
As the resin constituting the adjacent layer 252, a mixed resin in which a polypropylene (PP) resin and a polyethylene (PE) resin are blended at a predetermined ratio can be used. The blending ratio of PP and PE is not particularly limited, and is blended within the range of 100: 0 to 0: 100 according to the resin constituting the sealing layer 251 and the peel strength.
The thickness of the adjacent layer 252 is not particularly limited, but is preferably formed in a range of 10 μm or more. There exists a possibility that it may peel between the base material layer 253 and the adjacent layer 252 as the thickness of the adjacent layer 252 is less than 10 micrometers.
A more preferable range of the thickness of the adjacent layer 252 is 50 μm or more.

  Further, as the resin used for the seal layer 251, the melt index (MI) value is larger than the MI value of the resin used for the adjacent layer 252 adjacent to the seal layer 251, and the difference between these MI values is different. A resin that is 3 g / 10 min or more is selected. If the difference in MI value is less than 3 g / 10 min, the broken portion of the seal layer 251 is exposed on the flange portion 230 when opened, and the appearance is not beautiful.

The base material layer 253 is a layer that appears on the outer surface of the container body 200.
Examples of the resin constituting the base layer 253 include materials such as olefin resins such as polypropylene resins and polyethylene resins, polystyrene resins, polyester resins such as polyethylene terephthalate (PET), ethylene vinyl alcohol copolymers, and the like. Single layer sheets or laminated sheets of blend materials can be used.
These laminated sheets may be provided with an adhesive layer or an oxygen-absorbing resin layer between the layers. Examples of the constituent material of the adhesive layer include urethane-based or styrene-based elastomers, maleic anhydride-modified polypropylene, and ethylene vinyl acetate (EVA). Moreover, as an oxygen absorption resin layer, an ethylene vinyl alcohol copolymer (EVOH) etc. are mentioned, for example.

  The multilayer sheet 250 which consists of the sealing layer 251 / adjacent layer 252 / base material layer 253 can be produced by co-extrusion of the above resin, dry lamination, extrusion lamination, extrusion coating, or a combination thereof. In addition, the adhesive strength of each layer can be adjusted by the thickness of each layer, resin selection, a mixture ratio, etc.

The lid member 300 is a laminate composed of a plurality of layers. For example, PET 12 μm / ONy (biaxially stretched nylon) 15 μm / L-LDPE (low density polyethylene) 60 μm, PET 12 μm / ONy15 μm / CPP (unstretched polypropylene) 60 μm, etc. The layer structure is mentioned.
These laminated sheets can be produced by coextrusion, thermal lamination, dry lamination, or the like, and can also be carried out by combining them stepwise.

[Packaging container manufacturing equipment]
Next, the manufacturing apparatus which manufactures the packaging container 100 of 1st embodiment is demonstrated.
FIG. 5 is a schematic configuration diagram illustrating a part of the packaging container manufacturing apparatus according to the first embodiment.
The container body 200 is formed by thermoforming the multilayer sheet 250 by a known method such as plug assist vacuum forming or plug assist pressure forming. Here, a container body forming apparatus as a part of the container body 200 will be described. .

In FIG. 5, the manufacturing apparatus 400 includes a container body forming apparatus 500.
The container main body forming apparatus 500 is an apparatus for thermoforming the container main body 200 from the multilayer sheet 250. The mold 510 disposed on the side opposite to the side where the opening 220 of the multilayer sheet 250 is formed, and the mold A flange pressing member 520 disposed on the opposite side of the flange portion 230 of 510 and a plug 530 forming the opening 220 of the container main body 200 are provided.

In the mold 510, a recess 511 for forming the opening 220 of the container body 200 is formed in the central portion, and a flat portion 512 for forming the flange portion 230 is formed at the upper end edge of the recess 511. ing.
In this embodiment, the mold 510 is a mold for a cup having a diameter of 80 mm.

The flange presser 520 forms the flange part 230 of the container main body 200 by pressing the multilayer sheet 250 together with the flat part 512 of the mold 510.
The flange retainer 520 is formed in an annular flat plate shape along the outer edge of the opening of the recess 511 of the mold 510, and has a retainer surface 521 that faces the flat portion 512 of the mold 510. The pressing surface 521 has a gradient that protrudes in the direction of the mold 510 from the outer edge 522 to the inner edge 523 of the flange pressing member 520 formed in an annular shape, and the pressing surface 521 as a whole is formed flat.

  The pressing surface 521 is formed with a gradient in the range of 0.1 ° to 25 ° with respect to the flat portion 512 of the mold 510. When the gradient is less than 0.1 °, it is difficult to form a thin portion or a missing portion of the seal layer 251 in the vicinity of the inner edge portion 232 of the flange portion 230, and the easy-openability cannot be obtained. On the other hand, if the gradient exceeds 25 °, the sealing layer 251 may be caught in the flange presser 520 and the work may become difficult, which is not preferable. A more preferable range of the gradient is 3 ° to 15 °, and a more preferable range is 6 ° to 10 °. Since the flange pressing member 520 has a gradient on the pressing surface 521 as described above, when the flange portion 230 is formed, stress is concentrated on the inner peripheral side of the flange portion 230, and the seal layer 251 is partially formed. It can be thinned or missing.

Further, the flange presser 520 can be adjusted in the temperature range of 10 ° C. or more and 160 ° C. or less together with the mold 510. As the temperature of the flange presser 520 and the mold 510 is higher, the seal layer 251 can be more stably thinned or lost. Further, when the temperature exceeds 160 ° C., the temperature approaches the melting point of the resin constituting the seal layer 251, which may make it difficult to handle. A more preferable range of the temperature of the flange presser 520 is 100 ° C. or higher and 120 ° C. or lower.
Further, the flange presser 520 is connected to a spring 540, and the pressure can be adjusted by replacing the spring with a spring having a different spring constant.

  The plug 530 is formed in substantially the same shape with a smaller diameter than the recess 511 of the mold 510, and fits into the recess 511 with the multilayer sheet 250 interposed therebetween.

  By the container body molding apparatus 500 as described above, the multilayer sheet 250 is fed between the mold 510, the flange holder 520, and the plug 530, and in this state, the flange holder 520 and the plug 530 are moved to the mold 510 side. The concave portion 210 and the flange portion 230 for storing the contents are formed into the multilayer sheet 250 at a time, and the container body 200 can be formed.

[Method of manufacturing packaging container]
Next, a method for manufacturing the packaging container 100 of the first embodiment will be described.
The container body 200 is formed by thermoforming the multilayer sheet 250 by a known method such as plug-assist vacuum forming or plug-assisted pressure forming, and the container body forming apparatus 500 serves as a part thereof. .
First, the heated and softened multilayer sheet 250 is introduced into the container body forming apparatus 500.
When the multilayer sheet 250 reaches the upper surface side of the mold 510, the plug 530 is brought close to the multilayer sheet 250. In this case, the space surrounded by the plug 530 and the multilayer sheet 250 is sealed. Then, the multilayer sheet 250 is pre-formed, and high-pressure air is injected into a compressed air chamber (not shown) provided on the side of the plug 530 facing the multilayer sheet 250 and pressed against the recess 511 while being in a compressed air state. And formed into the shape of the container body 200.

At the same time as this step, the flange presser 520 is pressed against the flat part 512 of the mold 510 to form the flange part 230.
The flange retainer 520 is prepared by the spring 540 so that the pressure is in the range of 1.5 kg / cm ² or more and 20 kg / cm ² or less. When the pressure is less than 1.5 kg / cm ² or exceeds 20 kg / cm ² , it is difficult to make the seal layer 251 thin or missing, and it is difficult to open the seal layer.

  The temperature of the flange presser 520 is adjusted to be in the range of 10 ° C. or higher and 160 ° C. or lower. Even if the temperature is less than 10 ° C., the seal layer 251 can be thinned, but the container body 200 having the target shape can be manufactured more stably as the temperature becomes higher. On the other hand, when the temperature exceeds 160 ° C., it approaches the melting point of the resin used for the seal layer 251, so that the molding itself becomes unstable.

Next, the liquid which becomes the contents P is injected and filled in the multilayer sheet 250 formed in the shape of the container body 200.
And the lid | cover material 300 is mounted in the flange part 230 of the container main body 200, and these are heat-sealed. The strength of heat sealing is stronger than the adhesive strength between the sealing layer 251 and the adjacent layer 252 of the multilayer sheet 250. The adhesive strength of the heat seal can be adjusted by heat seal conditions such as temperature, pressure, time, the thickness of each layer, resin selection, and the like.
The heat seal is performed by pressing the seal bar against the flange portion 230 from above the lid member 300, and an annular seal portion 240 is formed between the heat-sealed container body 200 and the lid member 300. Become.

[How to open the packaging container]
A method for opening the packaging container 100 having such a configuration will be described with reference to FIGS. 3 and 4.
First, the grip part 310 of the sealed packaging container 100 shown in FIG. 3 is gripped. And if it pulls in the direction which opens the lid | cover material 300, holding the holding part 310, it will peel between the sealing layer 251 and the adjacent layer 252 of the container main body 200. FIG.
When the peeling position reaches the inner edge 232 of the flange portion 230 of the container body 200, the seal layer 251 is separated at the missing portion 251B of the seal layer 251 as shown in FIG. Then, in order from this separation position, the seal layer 251 is separated along the annular missing portion 251B, and the packaging container 100 is opened.

Therefore, in the present embodiment, the following operational effects can be achieved.
(1) The container body 200 is formed such that the thickness at the inner edge 232 of the flange portion 230 is 50% of the thickness at the outer edge 231, and has a missing portion 251 </ b> B along the inner edge 232.
For this reason, when opening the packaging container 100 in which the lid member 300 is sealed to the flange portion 230, the seal layer 251 and the adjacent layer 252 are peeled off, and the seal layer 251 can be easily separated by the missing portion 251B. it can. That is, it is excellent in easy openability. In addition, since the sealing layer 251 and the lid member 300 in the flange portion 230 are sealed before opening, the sealing performance is excellent.

(2) Further, the flange portion 230 has a gradient, and the seal surface 251A of the seal layer 251 of the flange portion 230 is formed flat.
For this reason, in order to mold the container body 200, it is only necessary to provide a gradient on the pressing surface 521 of the flange pressing member 520 for forming the flange portion 230. By using the flange presser 520 provided with the gradient, the flange portion 230 having the gradient can be easily formed by performing the same molding process as the conventional one. Therefore, the container body 200 having a shape excellent in easy-openability can be manufactured by a single process of pressing the multilayer sheet 250 with the flange presser 520 and the flat portion 512 of the mold 510. That is, the molding process is simple, and the molding capacity of the conventional container body 200 can be maintained.
Further, when the lid member 300 and the container body 200 are sealed, the position control of the seal portion 240 is not required. That is, it is possible to easily manufacture a container that achieves both easy opening and high sealing. As a result, the overall manufacturing cost can be reduced.

(3) Since the flange 230 has a configuration in which a gradient is simply provided, the manufacturing method does not need to be changed greatly and can be easily manufactured, and a stable supply of the packaging container 100 can be provided.

(4) The pressing surface 521 of the flange pressing 520 has a gradient of 6 ° with respect to the surface direction of the flat portion 512 of the mold 510.
For this reason, when the flange portion 230 is formed by the flange presser 520 and the mold 510, the thickness of the inner edge portion 232 of the flange portion 230 can be about 50% of the thickness of the outer edge portion 231. That is, since the missing portion 251B in which the seal layer 251 is missing can be easily formed on the inner peripheral side of the flange portion 230, labor is not required and the manufacturing cost can be reduced.

(5) Since the stepped portion 213 is provided in the opening 220 of the container body 200, it becomes easy to form a thin portion or a missing portion of the seal layer 251 on the inner peripheral side of the flange portion 230, and stress is concentrated at the time of opening. It is easy to do and is easy to open.

[Second Embodiment]
Next, 2nd embodiment is described using FIG.6, FIG.7 and FIG.8.
FIG. 6 is a perspective view showing a sealed state of the packaging container according to the second embodiment of the present invention. 7 is a sectional view taken along line VII-VII in FIG. FIG. 8 is a cross-sectional view showing a state where a part of the packaging container of FIG. 6 is opened.

[Composition of packaging container]
Since the second embodiment has the same configuration as that of the first embodiment except that the shape of the flange portion of the packaging container is different, only the shape of the flange portion will be described. The easy separation means in the second embodiment is a missing portion where the seal layer 251 is missing.
In FIG. 6, the packaging container 600 has a flange portion 260 formed in a skirt shape. The flange portion 260 includes a substantially flat flat portion 261 sealed with the lid member 300 by the seal portion 240, a skirt portion 262 formed in a skirt shape from the outer peripheral edge of the flat portion 261, and a skirt portion 262. The edge part 263 extended in parallel with the planar direction of the flat part 261 from the outer peripheral edge of this is provided. Here, the skirt portion 262 and the end edge portion 263 correspond to the extending portion of the present invention. In the flat portion 261, the seal layer 251 is sealed with the lid member 300 to form the seal portion 240.

The flat part 261 is located between the inner edge part 261A which is the innermost peripheral edge forming the opening 220 of the container body 200, the outer edge part 261B which is the outermost peripheral edge of the flat part 261, and the inner edge part 261A and the outer edge part 261B. The central portion 261C is located.
The flat portion 261 is formed so that its thickness gradually decreases from the central portion 261C to the inner edge portion 261A and the outer edge portion 261B. When the thickness A of the inner edge portion 261A, the thickness B of the outer edge portion 261B, and the thickness C of the central portion 261C, the flat portion 261 is set so that the values of A / C and B / C are in the range of 20% to 98%. Is formed.
In the second embodiment, an annular missing portion 251B in which the seal layer 251 is missing is formed along the inner edge portion 261A and the outer edge portion 261B of the flat portion 261. Accordingly, the thicknesses of the inner edge portion 261A and the outer edge portion 261B are, for example, A / C = 50% and B / C = 50% with respect to the central portion 261C. The inner edge 261A and the outer edge 261B may have the same thickness or different thicknesses.

[Packaging container manufacturing equipment]
Next, the manufacturing apparatus which manufactures the packaging container 600 of 2nd embodiment is demonstrated.
In the manufacturing apparatus of the first embodiment shown in FIG. 5, only the shape of the flange presser 520 is different.
The pressing surface of the flange pressing member in the second embodiment has a gradient that protrudes in the direction of the mold 510 from the center ring portion of the flange pressing member formed in an annular shape to the inner edge side or the outer edge side. This gradient is formed in the range of 0.1 ° to 25 ° with respect to the flat portion 512 of the mold 510. If the gradient is less than 0.1 °, it is difficult to form the missing portion 251B in the vicinity of the inner edge portion 261A and the outer edge portion 261B of the flat portion 261, and the easy-openability cannot be obtained. On the other hand, if the gradient exceeds 25 °, the seal layer 251 may be caught in the flange presser and the work may become difficult, which is not preferable. A more preferable range of the gradient is 3 ° to 15 °, and a more preferable range is 6 ° to 10 °. Since the flange pressing has a gradient on the pressing surface in this way, when the flat portion 261 is formed, stress is concentrated on the inner edge portion 261A and the outer edge portion 261B of the flat portion 261, and the seal layer 251 is partially separated. Can be thinned or missing.

[Method of manufacturing packaging container]
Since it is the same as that of 1st embodiment except using the flange presser in 2nd embodiment, description is abbreviate | omitted here.

[How to open the packaging container]
Next, a method for opening the packaging container 600 in the second embodiment will be described with reference to FIGS.
First, the grip part 310 of the sealed packaging container 600 shown in FIG. 7 is gripped. When the lid member 300 is pulled in the direction of opening while holding the grip portion 310, the missing portion 251B in the outer edge portion 261B of the flat portion 261 is used as a peeling start position, and the seal layer 251 and the adjacent layer 252 of the container body 200 are separated. Separation occurs.
When the peeling position reaches the inner edge portion 261A of the flat portion 261, as shown in FIG. 8, the seal layer 251 is separated at the missing portion 251B. Then, in order from this separation position, the seal portion 240 is peeled along the annular missing portion 251B, and the packaging container 600 is opened.

  Therefore, also in the packaging container of the configuration of the second embodiment, the same operational effects as described above can be achieved.

  It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.

  For example, in the embodiment, the missing portion 251B in which the seal layer 251 is missing is formed along the inner edge 232 (261A) of the flange portion 230 (flat portion 261), but a thin portion may be used instead of the missing portion 251B. . Also in this case, it can be easily formed by adjusting the gradient of the pressing surface of the flange pressing. In addition, when setting it as a thin part, the gradient of the pressing surface of a flange pressing is made smaller than the flange pressing which formed the missing part 251B, the pressure of a flange pressing is made small, or the temperature of a flange pressing is set low. Can be realized. What is necessary is just to adjust suitably so that it can be set as desired thickness.

  Moreover, in the said embodiment, although the sealing layer 251 was provided in the container main body, you may provide a sealing layer in the lid | cover material 300. FIG. In such a configuration, the seal layer of the lid member 300 can be partially thinned or missing by providing a gradient on the seal surface of the seal bar when the lid member 300 is sealed to the flange portion. is there.

Furthermore, in the above embodiment, heat sealing is used as means for sealing the lid material to the flange portion, but ultrasonic waves, adhesives, or the like may be used.
And in the said embodiment, although the shape of the packaging container was made into planar circle shape, it is not restricted to this, A planar rectangular shape and another shape may be sufficient.

  In the second embodiment, the flange portion is formed in a skirt shape by the flat portion 261, the skirt portion 262, and the end edge portion 263, but is not limited thereto. For example, it may be configured to extend in a curl shape from the vicinity of the outer edge portion of the flat portion, or only the end edge portion 263 may be formed in a curl shape. Thus, it can respond to the packaging container which has a flange part of various shapes.

Further, in the second embodiment, the inner edge portion 261A and the outer edge portion 261B of the flat portion 261 are thinned. However, only the outer edge portion 261B is thinned, and the sealing layer 251 is easily separated by the inner edge portion 261A. It is good also as a structure which formed the notch part.
Further, a cutout portion may be formed in the seal layer 251 at the outer edge portion 261B of the flat portion 261, and the inner edge portion 261A may be thinned.

  EXAMPLES Next, although an Example is given and this invention is demonstrated in more detail, this invention is not restrict | limited at all to the content of description of these Examples.

[Test 1]
<Manufacture of container body>
A sheet used for the container body was manufactured by a commonly used distributor type coextrusion multilayer sheet manufacturing apparatus. The sheet is an 8-layer multilayer sheet shown below.
1. Seal layer: HDPE (high density polyethylene, “1300J” manufactured by Prime Polymer Co., Ltd.) or PP (“J3021GR” manufactured by Prime Polymer Co., Ltd.)
2. Adjacent layer 1: PP (“E-105GM” manufactured by Prime Polymer Co., Ltd.) or PP (“E-105GM” manufactured by Prime Polymer Co., Ltd.) / PE (“HE30” manufactured by Nippon Polyethylene Co., Ltd.) blend (blending ratio 5: 5 )
3. Base material layer 1: PP (“E-105GM” manufactured by Prime Polymer Co., Ltd.)
4). Adhesive layer 1: maleic anhydride-modified PP (“Modic AP P502” manufactured by Mitsubishi Chemical Corporation)
5. EVOH layer: "Eval J" manufactured by Kuraray Co., Ltd.
6). 6. Adhesive layer 2: same as adjacent layer 1 Base material layer 2: same as base material layer 1 8. Adjacent layer 2: Same as adjacent layer 1

Using the multilayer sheet, the packaging container (flat flange mold) shown in FIG. 1 was formed by plug assist + flange clamp vacuum / pressure forming used in the embodiment. Various conditions are as follows.
Mold: A round shape with an inner peripheral side contour φ78, an outer peripheral side contour φ84, and a cup shape having a 3 mm wide flange.
Flange presser: Container bodies were prepared by changing the pressure, taper, and temperature conditions (see Tables 1 and 2).

<Seal for lid>
As the lid material, a laminate film having the following two types of layer structures was used.
A: Polyethylene terephthalate (PET, 12 μm) / biaxially stretched nylon (ONy, 15 μm) / linear low density polyethylene (LLDPE, 60 μm)
B: Polyethylene terephthalate (PET, 12 μm) / biaxially stretched nylon (ONy, 15 μm) / unstretched polypropylene (CPP, 60 μm)

  The LLDPE surface or CPP surface of the laminate film is applied to the flange portion of the obtained container body, and the seal bar is pressed from the PET surface under the conditions of a temperature of 195 ° C., a seal pressure of 150 kg / piece, and a seal time of 1.2 seconds. Then, it was heat sealed and bonded. The seal bar is formed in an annular shape having an outer peripheral contour of φ86 and an inner peripheral contour of φ76, and has a flat contact surface over the entire surface.

<Evaluation>
By the above method, packaging containers of Examples 1 to 13 and Comparative Examples 1 to 4 and Comparative Examples 5 and 6 shown in Table 1 and Table 2 below are prepared, and the internal pressure strength measurement and the opening portion are performed. Peel strength measurement and evaluation of opening feeling were performed. The results are shown in Table 1 and Table 2.
Here, the thickness of the outermost periphery of the flange portion of the container body is X, and the thickness of the innermost periphery is Y. The difference in melt index between the seal layer of the container body and the adjacent layer is defined as the MI difference.

[Comparative Example 5] Container obtained in JP-A-62-1251363 (Patent Document 1)

[Comparative Example 6] Container obtained in JP-A-7-309368 (Patent Document 3)

<1. Internal pressure strength measurement>
This was performed according to “JIS-Z0238” using a burst strength measuring instrument manufactured by San Kagaku Co., Ltd. Specifically, an adhesive rubber sheet piece was affixed to the surface of the lid member, a needle was inserted therein, air was fed, and the numerical value when the container burst was measured.

<2. Peel strength measurement>
Using a digital force gauge manufactured by IMADA, the container body after sealing is cut into a 15 mm width together with the cover material in the same manner as the sealing strength measurement method for packaging bags described in “JIS-Z0238”. The tensile strength was measured at 135 ° with respect to the container flange surface.

<3. Evaluation of feeling of opening>
(Double-circle): A surface layer is missing completely, and opening is also favorable.
◯: Although the elongation of the surface layer within 2 mm can be confirmed, missing occurs and the opening is good.
Δ: Elongation of the surface layer of 2 mm or more occurs, and opening is possible but the easy opening feeling is impaired.
X: Opening is difficult for reasons such as missing or insufficient surface layer.

As can be seen from Tables 1 and 2, in Examples 1 to 13, the ratio of the innermost circumferential thickness Y to the outermost circumferential thickness X of the flange portion is within a predetermined range, so that good results are obtained. It was.
Moreover, in Example 2 and Example 4, since the flange pressing pressure was within a predetermined range, a better result was obtained than in Comparative Example 1. In Comparative Example 1, since the pressure of the flange presser was too small, a thin portion or a missing portion could not be formed, and easy-openability could not be obtained.
In Example 5, Example 6 and Example 2, since the flange pressing taper was set within a predetermined range, a better result was obtained than in Comparative Examples 2 and 3.

In Example 7 and Example 2, good results were obtained because the MI difference between the seal layer and the adjacent layer was within a predetermined range. In Example 8, since the MI difference was not within the predetermined range, it was inferior to Example 7, but was practically satisfactory.
In Examples 9 to 13, since the temperature of the flange presser was set within a predetermined range, better results were obtained than in Comparative Example 4. Moreover, when Examples 9-13 are compared, it turns out that it can shape | mold more stably, so that the temperature of a flange presser becomes high. In Example 11, the value of Y / X was as high as 80%, but since the temperature of the flange presser was relatively high at 120 ° C., it could be molded stably and a good opening feeling was obtained. In Comparative Example 4, since the temperature of the flange presser was too high and was close to the melting point of the seal layer, the molding itself became unstable and the evaluation was bad.

  Moreover, the comparative example 5 created by the prior art was inferior to the present invention in all of the internal pressure strength, the opening strength, and the opening feeling. Although Comparative Example 6 was excellent in internal pressure strength, opening strength, and opening feeling, there was a problem in its productivity, and it took time and cost.

[Test 2]
Next, the container main body in the packaging container (skirt flange type) shown in FIG. 6 was molded using the multilayer sheet used in Test 1.
Various conditions at the time of molding the container body are as follows.
Mold: A round mold with a contour φ78 on the inner peripheral side of the flange portion and a contour φ84 on the outer peripheral side, and a cup shape having a flange with a width of 3 mm.
Flange presser: Container bodies were prepared by changing the pressure, taper, and temperature conditions (see Tables 3 and 4). The taper is applied so as to drop from the central portion of the flat portion toward the inner edge portion and the outer edge portion of the flat portion.
And the lid | cover material used by Test 1 was mounted in the flange part of the shape | molded container main body, the seal bar used by Test 1 was pressed, heat-sealed, and it adhere | attached. Also, in order to improve the easy separation at the missing portion 251B on the inner peripheral side of the flange portion, press the seal bar formed in an annular shape with an outer peripheral contour of φ86 and an inner peripheral contour of φ76, The position adjacent to the missing part 251B was heat-sealed. This seal bar is 5 mm wide and has a flat contact surface over the entire surface.

<Evaluation>
By the above method, the packaging containers of Examples 14 to 27 and Comparative Examples 7 to 13 shown in Table 3 and Table 4 below are prepared, and the internal pressure strength measurement, the opening strength measurement at the opening portion, and the evaluation of the opening feeling are performed. Carried out. The measurement method is the same as in Test 1. The results are shown in Tables 3 and 4.
Here, the thickness of the innermost periphery and the outermost periphery of the flange portion of the container body is the same, Y, and the thickness of the center portion of the flange portion is X. The difference in melt index between the seal layer of the container body and the adjacent layer is defined as the MI difference.

As can be seen from Table 3 and Table 4, in Examples 14 to 27, the ratio of the innermost circumference and the outermost thickness Y to the thickness X of the central portion of the flange portion is within a predetermined range. Good results were obtained compared to 8 and 8.
Further, in Examples 17 and 18, since the pressure of the flange pressing was within a predetermined range, a better result was obtained than in Comparative Example 9. In Comparative Example 9, since the pressure of the flange presser was too small, a thin portion or a missing portion could not be formed, and easy-openability could not be obtained.
In Examples 19 to 21, since the flange pressing taper was set within the predetermined range, better results were obtained than in Comparative Examples 10 and 11.

In Examples 22 and 23, since the MI difference between the seal layer and the adjacent layer was within a predetermined range, a better result was obtained than in Comparative Example 12.
In Examples 24-27, since the temperature of the flange presser was set within a predetermined range, a better result was obtained than in Comparative Example 13. Moreover, when Examples 24-27 are compared, it turns out that it can shape | mold more stably, so that the temperature of a flange presser becomes high. In Comparative Example 13, the temperature of the flange presser was too high and was close to the melting point of the seal layer, so that the molding itself became unstable and the evaluation was bad.

  The present invention can be widely used as a packaging container for various foods such as retort foods, medicines, cosmetics, and the like.

The perspective view which shows the sealed state of the packaging container concerning 1st embodiment of this invention. The perspective view which shows the state by which a part of packaging container concerning 1st embodiment of this invention was opened. III-III sectional drawing of FIG. IV-IV sectional drawing of FIG. Sectional drawing which shows a part of outline | summary of the manufacturing apparatus of the packaging container concerning 1st embodiment of this invention. The perspective view which shows the state by which the packaging container concerning 2nd embodiment of this invention was sealed. VII-VII sectional drawing of FIG. Sectional drawing which shows the state in which a part of packaging container of FIG. 6 was opened.

Explanation of symbols

DESCRIPTION OF SYMBOLS 100 ... Packaging container 200 ... Container main body 230 ... Flange part 231 ... Outer edge part 232 ... Inner edge part 240 ... Seal part 250 ... Multilayer sheet 251 ... Sealing layer 251B ... Missing part 252 ... Adjacent layer 253 ... Base material layer 260 ... Flange part 261 ... Flat part 262 ... Skirt part 263 ... Edge edge part 300 ... Cover material P ... Contents

Claims (11)

A packaging container comprising a container body in which a flange portion is formed on the periphery of the opening, and a lid member that closes the opening and is sealed between the flange by a seal portion,
At least one of the container main body and the lid member includes at least two layers of a seal layer and a base material layer,
The seal layer has a thin-walled portion or a missing portion on the inner peripheral side of the flange portion,
The flange portion has a thickness of an inner edge portion of 20% to 98% with respect to a thickness of an outer edge portion thereof. A packaging container comprising a container body in which a flange portion is formed on the periphery of the opening, and a lid member that closes the opening and is sealed between the flange by a seal portion,
The flange portion has a flat flat portion on which a seal portion is formed, and an extending portion that extends to the outer peripheral edge of the flat portion,
At least one of the container main body and the lid member includes at least two layers of a seal layer and a base material layer,
The seal layer has a thin part or a missing part on at least one of the outer peripheral side and the inner peripheral side of the flat part, and has an easy separation means that can be easily separated on the other side,
The flat part has a thickness of 20% or more and 98% or less on the side having the thin part or missing part with respect to the thickness of the central part. The packaging container according to claim 2,
The easy separation means is a thin portion or a missing portion,
The packaging container, wherein the flat part has a thickness of 20% or more and 98% or less on a side having the easy separation means with respect to a thickness of a central part thereof. In the packaging container according to any one of claims 1 to 3,
The melt index (MI) value of the seal layer is larger than the MI value of the adjacent layer adjacent to the seal layer, and the difference between the MI value of the seal layer and the MI value of the layer adjacent to the seal layer is 3 g. A packaging container characterized by being / 10 min or more. It is a manufacturing method of the packaging container according to any one of claims 1 to 4,
A method for manufacturing a packaging container, wherein a container forming step for providing a gradient in the flange portion is performed using a flange presser having a pressing surface for pressing the flange portion and a mold for forming the container body. . In the manufacturing method of the packaging container of Claim 5,
The method of manufacturing a packaging container, wherein the flange presser presses the flange portion with a pressure of 1.5 kg / cm ² or more and 20 kg / cm ² or less. In the manufacturing method of the packaging container of Claim 5 or Claim 6,
The method of manufacturing a packaging container, wherein the flange pressing has a slope on the pressing surface. In the manufacturing method of the packaging container according to claim 7,
The manufacturing method of a packaging container, wherein the flange pressing is provided with a gradient of 0.1 ° to 25 ° on the pressing surface. In the manufacturing method of the packaging container as described in any one of Claim 5 to Claim 8,
The method of manufacturing a packaging container, wherein the flange presser and the mold press the flange portion at a temperature of 10 ° C or higher and 160 ° C or lower. It is a manufacturing apparatus of the packaging container according to any one of claims 1 to 4,
A mold having a concave portion for forming the container body and a flat portion for forming the flange portion;
An apparatus for manufacturing a packaging container, comprising: a flange presser having a slope with respect to the flat portion. In the manufacturing apparatus of the packaging container according to claim 10,
The apparatus for manufacturing a packaging container, wherein the gradient is provided in a range of 0.1 ° to 25 ° on a pressing surface that presses the flange portion.

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