JP5943247B2 - Cup-shaped container - Google Patents

Description

The present invention relates to a cup-shaped container, which is a synthetic resin injection-molded product in which an in-mold label is provided on a container body having an outer flange-shaped flange.

  Consists of a cylindrical body with a bottom, an injection molded container body having an outer flange-like flange connected to the opening of the trunk, and an in-mold label having a function as a reinforcing member Synthetic resin cup-shaped containers are used in large quantities as simple disposable containers.

  The cup-shaped container as described above is used so as to seal the container by adhering a lid material such as aluminum foil or resin synthetic paper using the upper surface of the flange portion of the container. However, the flange portion may be damaged due to a strong stress acting on the flange portion due to dropping or impact during transportation. Therefore, realization of a cup-shaped container having a structurally strong flange portion is required.

Even in the cup-shaped container with an in-mold label as described above, since the label display must be clearly visible from the outside of the container, the in-mold label is often provided on the outer peripheral surface of the body portion of the container body. This in-mold label is configured by laminating an adhesive layer formed by applying a hot-melt adhesive that adheres by thermal welding to a label layer having functions such as display and reinforcement.
When such an in-mold label is placed in a molding die and a container body is formed by injection molding, the label layer and the container body are strongly welded by the high-temperature molten resin from which the adhesive layer of the in-mold label is injected. As well as having a structure, a structurally reinforced container can be formed.

  Further, in the cup-shaped container described above, internal stress due to impact or pressing load tends to concentrate on the boundary part (hereinafter referred to as a corner part) between the flange and the trunk part, which is a part of the container body. When the upper edge of the in-mold label is arranged near the corner, the thickness of the container body changes at the upper edge of the in-mold label. Since the above-mentioned internal stress concentrates on the portion where the thickness has changed (hereinafter referred to as the thickness change portion), cracks are more likely to occur in the portion, and there is a risk of causing greater damage such as breakage in the body portion.

Therefore, in such a cup-shaped container with an in-mold label, in order to prevent the above-mentioned crack from occurring in the body part, by forming the upper edge part of the in-mold label so as to slightly bite into the flange, Some containers have been devised so as not to place a thickness-change portion where cracks are likely to occur due to concentration of internal stress in the vicinity of the corner of the trunk.
Moreover, there exists a container of the structure which provided the in-mold label to the middle of the flange lower surface by the same meaning (patent document 1).

However, in the case where the upper edge portion of the in-mold label is formed so as to slightly bite into the flange, or in the configuration in which the in-mold label is provided partway down the flange, the above-described meat is applied to the flange. Since the thickness changing portion is formed, the internal stress is concentrated on the portion, which may cause a crack.

When such a crack is generated in the flange, there is a possibility that a larger damage such as breakage may be caused by the generated crack, as in the case where the crack is generated in the body portion.
As described above, both the containers have structural problems as the entire flange portion.

JP 2009-227316 A

Therefore, the present invention was devised to solve the above-described problems in the prior art, and it is intended to reinforce the structure of the entire flange portion by utilizing an in-mold label having a function as a reinforcing member. One purpose.
In addition, by minimizing the formation of thickness-changing parts that cause cracks due to the concentration of internal stress, the flange structure with a problem in strength is improved, and cracks are not generated due to impact during dropping or transportation. By taking suppression as the second object, a synthetic resin cup container with an in-mold label that is strong and structurally excellent is provided.

The main configuration of the present invention is as follows.
Consists of a cylindrical body with a bottom, an injection molded container body having an outer flange-like flange connected to the opening of the trunk, and an in-mold label having a function as a reinforcing member A synthetic resin cup-shaped container,
The in-mold label is continuously provided from the body portion to the outer peripheral end of the lower surface of the flange, and has an extensibility that can be expanded and deformed along the lower surface of the flange.
The in-mold label forms an arcuate surface having a curvature at the inner corner of the corner that is the boundary between the body and the flange, so that it can be easily expanded and deformed along the lower surface of the flange.
The in-mold label is composed of a label layer having a function as a reinforcing member, an adhesive layer that strongly bonds the label layer and the container body by thermal welding, and a surface layer that protects the label layer.
The surface layer is formed from a material compatible with the resin material constituting the container body.

  According to the above configuration, the in-mold label having a function as a reinforcing member has an extensibility that can be expanded and deformed from the body portion along the lower surface of the flange. The in-mold label thus formed is expanded and deformed from the corner portion, and is continuously provided to the outer peripheral end of the flange lower surface. For this reason, since the in-mold label which has a function as a reinforcement member can be provided in the whole region of a flange lower surface, a strong structure can be realized as the whole flange portion.

  Further, the thickness of the flange is constant over the entire surface of the flange portion, and internal stress does not concentrate on a specific portion. That is, since there is no portion for concentrating the internal stress on the flange, it is possible to suppress the generation of cracks caused by the concentration of the internal stress, and to prevent breakage caused by the cracks.

Another configuration of the present invention is the above main configuration,
The in-mold label is provided from the lower end edge of the outer peripheral surface of the body part,
That's it.

  According to the said structure, although the in-mold label is provided from the outer peripheral surface lower end edge of the trunk | drum, this is provided continuously with the in-mold label provided in the whole region of the flange lower surface. That is, since the label has a structure covering the entire region from the lower end edge of the body part to the outer edge of the flange, the occurrence of cracks as described above can be suppressed for the entire container, and a strong cup-shaped container can be configured.

According to the main configuration, when the upper and lower sides or both peripheral edges of the in-mold label are in contact with the container body, the surface layer forming the outer surface of the in-mold label is firmly bonded to the container body at the contact surface. The As described above, the thickness of the container body changes at the top and bottom or both peripheral edges of the in-mold label, so that internal stress tends to concentrate and cracks easily occur. Since the welded portion between the surface layer and the container body is reinforced, the occurrence of cracks can be suppressed.

According to the above main configuration, the inner corner portion of the corner portion that is the boundary portion between the body portion and the flange is formed into a circular surface having a curvature that allows the in-mold label to be expanded and deformed along the lower surface of the flange. When molding a container by molding, the in-mold label can be expanded and deformed smoothly along the lower surface of the flange, so that an in-mold label without a fold or wrinkle can be provided.

In other words, in the present invention, the in-mold label provided in a wound shape at the body portion is provided in the entire area of the lower surface of the flange by expanding and deforming at the lower surface portion of the flange. Therefore, the in-mold label is curved at an inner corner portion that is a boundary portion between a portion provided in a wound shape on the body portion and a portion provided radially on the flange. By forming the curved portion in a circular arc shape having a curvature that facilitates expansion and deformation of the diameter, the curved portion can be smoothly curved and folds and wrinkles can be prevented.

Since the present invention has the above-described configuration, the following effects can be obtained.
That is, according to the above configuration, the in-mold label having a function as a reinforcing member is formed by winding the in-mold label in the body portion so that the in-mold label is enlarged and deformed from the corner portion, and the outer periphery of the flange lower surface Since it is provided continuously to the end, an in-mold label having a function as a reinforcing member can be provided over the entire area of the lower surface of the flange, so that a strong structure can be realized as the entire flange portion. In addition, the flange as a part of the container body has a constant thickness, and internal stress is not concentrated on a specific portion, and the occurrence of cracks can be suppressed.
For this reason, the unexpected breakage during conveyance can be prevented. Further, it can be realized by thinning a container having the same strength as the conventional one.

  Furthermore, in the case where the in-mold label is provided from the lower end edge of the outer peripheral surface of the body part, since it is provided continuously with the in-mold label provided in the entire area of the lower surface of the flange, even as a whole container, A strong cup-shaped container can be constructed.

  In addition, when the surface layer of the in-mold label is made of a material compatible with the resin material constituting the container body, it is of course possible that the adhesive layer of the in-mold label and the container body can be firmly bonded by thermal welding. In the upper and lower and both peripheral edges of the in-mold label, the contact portion between the surface layer of the in-mold label and the container body is thermally welded, so the cracks in the portion where the thickness changes and the internal stress concentrates Generation | occurence | production can be prevented and a strong cup-shaped container can be formed.

Furthermore, if the inner corner of the corner, which is the boundary between the body and the flange, is formed on an arcuate surface having a curvature that allows the in-mold label to expand and deform along the lower surface of the flange, The mold label is most curved at the inner corner, which is the boundary between the portion provided in a wound form on the body and the portion provided on the flange, but has a curvature that facilitates expansion and deformation of the curved portion. Since it is formed on the circular arc surface, it can be smoothly bent and folds and wrinkles can be prevented.
Therefore, the label can be smoothly bent and molded at the time of injection molding, and a label that is beautiful in appearance is provided.

The perspective view of the container of a present Example The front view of the container of a present Example. The perspective view in the reverse state of the container of a present Example Enlarged view of part C1 in FIG. The enlarged view (a) of C11 part of FIG. 4, the label structure (b) of the figure. Layout view of the mold apparatus for forming the container of this embodiment (label placement stage) Enlarged view of the portion corresponding to the corner of FIG. Arrangement of mold apparatus for forming the container of this embodiment (filling stage) Layout of the mold apparatus for forming the container of this embodiment (completion stage) Enlarged view (a) of C2 in FIG. 8, enlarged view (b) of C3 in FIG. Sectional view of the A-A 'section of FIG.

DESCRIPTION OF EXEMPLARY EMBODIMENTS Hereinafter, embodiments of the invention will be described with reference to the accompanying drawings.
1 to 5 show one embodiment of a synthetic resin cup-shaped container with an in-mold label according to the present invention, FIG. 1 is a perspective view, and FIG. 2 is a front view. FIG. 3 is a perspective view with the bottom portion up (in an inverted state).
FIG. 4 is an enlarged view of a portion C1 in FIG. FIG. 5A is an enlarged view of the C11 portion, and FIG. 5B shows the label structure of FIG.

  The cup-shaped container 1 with an in-mold label in the present invention is composed of an injection-molded container body 2 and an in-mold label 8 as shown in FIGS. 1 to 3, and the container body 2 (FIG. 3). 2) has a bottom portion 7 and a flange 4 is provided around the upper end opening edge of the cylindrical body portion 3 having a diameter slightly increased upward, and a lower end portion of the body portion 3 lower than the bottom portion 7 is provided. The leg portion 6 is used.

The in-mold label 8 functions as a reinforcing member, and has extensibility that can be expanded and deformed along the lower surface of the flange 4. This in-mold label 8 is provided up to the outer peripheral end of the lower surface of the flange 4 that is a part of the container body 2 by in-mold molding. That is, as shown in FIGS. 1 to 3, the flange 4 and the in-mold label 8 form a reinforced flange 4 a that is a flange portion of the cup container 1.
Since the in-mold label 8 has an extensibility that can be expanded and deformed along the lower surface of the flange 4, the in-mold label 8 has a flange from an inner corner portion 5 a that is an outer surface portion of the corner portion 5 that is a boundary portion between the body portion 3 and the flange 4. By extending and expanding the diameter of the flange 4 to the outer peripheral end of the flange 4 along the lower surface, it can be provided continuously without a break. Therefore, the flange 4 is reinforced by an in-mold label 8 having a function as a reinforcing member over the entire surface.
As shown in FIG. 2, the upper edge of the in-mold label 8 is disposed at the outer peripheral end of the flange 4 without contacting the container body 2. Therefore, unlike the container of Patent Document 1, there is no thickness change portion of the flange 4 formed at the contact portion between the upper edge of the in-mold label 8 and the flange 4.
For this reason, it is possible to reinforce the entire flange 4 as described above and to suppress the occurrence of cracks due to concentration of internal stress.

In addition, as shown in FIG. 3, the in-mold label 8 provided in a wound shape on the outer peripheral surface of the body portion 3 that is a part of the container body 2 has the lower end edge of the label disposed on the lower end edge of the body portion 3. Yes. Therefore, like the flange 4 described above, there is no thickness change portion of the body portion 3 formed at the contact portion between the lower end edge of the in-mold label 8 and the body portion 3.
For this reason, the in-mold label 8 can reinforce the whole trunk | drum 3 and can suppress the crack generation resulting from the concentration of internal stress.

  As described above, in this embodiment, the lower surface of the flange 4 is reinforced over the entire surface by the in-mold label 8 having a reinforcing function, and the reinforced flange 4a reinforced by the action of both the flange 4 and the in-mold label 8 is provided. It is formed as a flange portion of the cup-shaped container 1. Furthermore, since the thickness change part is not formed in the flange 4, internal stress does not concentrate on a specific location, but generation | occurrence | production of a crack can be suppressed.

The in-mold label 8 has a three-layer structure (see FIGS. 4 and 5). The label layer 8 b has an extensibility that can be expanded and deformed along the lower surface of the flange 4. It also has a reinforcing function. The adhesive layer 8a is formed by applying an adhesive that strongly bonds the label layer 8b and the container body 2 by heat welding. This can be formed by applying a general hot-melt adhesive.
The surface layer 8c has a function of protecting the label layer 8b. This is formed from a resin compatible with the container body 2. Therefore, the surface layer 8 c is strongly welded to the container main body 2 at the portion where the surface layer 8 c comes into contact with the container main body 2, that is, at the upper and lower sides of the in-mold label 8 and the contact portion between both peripheral edges.
In this portion, the thickness changing portion is formed as described above, so that the internal stress is easily concentrated and a crack is likely to occur. However, since the portion can be reinforced from the outside by the surface layer 8c, the occurrence of cracks can be suppressed.

In the present embodiment, as described above, there is no contact portion between the upper and lower edges of the in-mold label 8 and the container body 2.
However, as shown in FIG. 4, the body portion that is part of the container main body 2 is disposed between the peripheral edge of the in-mold label 8 that is positioned in abutment with a portion of the body portion 3 and the flange 4. 3 or a part of the flange 4 that is partially exposed may be formed.

Ideally, the seam 9 of the label as described above should not be formed.
However, in reality, when the in-mold label 8 is provided on the body 3 in a wound shape, if both peripheral edges of the in-mold label 8 overlap, the overlapping portion does not strongly heat-weld, so Peeling may occur. In addition, the aesthetics are impaired by overlapping labels.

  Accordingly, in many cases, both peripheral edges of the in-mold label 8 are arranged in abutting manner in order to allow some margin so as not to overlap the peripheral edges of the in-mold label 8 as described above. .

  In this case, the label alignment in which the body part 3 or the flange 4 which is a part of the container body 2 is partially exposed between both peripheral edges of the in-mold label 8 positioned in a butting manner. Eyes 9 are formed. At the seam 9 of the label, since the thickness changing portion of the container body 2 is formed, there is a risk of cracking due to concentration of internal stress.

However, in this embodiment, the surface layer 8c has a function of protecting the label layer 8b and at the same time is formed of a resin compatible with the container body 2, so that the surface layer 8c and a part of the container body 2 A certain flange 4 is welded in the range of the thickness d of the surface layer 8c (FIG. 5).
Therefore, it is possible to prevent the occurrence of cracks caused by stress concentration in the portion.

  As shown in FIG. 4, the inner corner portion 5 a of the corner portion 5, which is a boundary portion between the body portion 3 and the flange 4, has a curvature r that allows the in-mold label 8 to be easily expanded and deformed along the lower surface of the flange 4. It is formed in a circle. The in-mold label 8 provided in a wound shape in the body 3 is expanded and deformed at the lower surface portion of the flange 4 so as to be provided in the entire area of the lower surface of the flange 4.

  As shown in FIG. 4, the in-mold label 8 is curved at an inner corner portion 5 a that is a boundary portion between a portion provided on the body portion 3 in a wound shape and a portion provided on the lower surface of the flange 4. By forming the curved portion into an arcuate surface having a radius of curvature r so that it can be easily expanded and deformed, the in-mold label 8 is smoothly curved at the portion to prevent the generation of folds and wrinkles. .

  As will be described in detail below, in the mold apparatus for injection molding, the mold surface corresponding to the inner corner portion 5a is formed as an arcuate surface having the same curvature. Accordingly, during injection molding, the in-mold label 8 can be expanded and deformed smoothly along the arc surface of the mold, so that unnatural folds and wrinkles occur in the in-mold label 8 at the portion. There is nothing.

  6 to 11 show a method for forming a container of the present invention. FIG. 6 is a diagram illustrating the arrangement of the molds of the container according to the present embodiment, and shows a state at the stage where the in-mold label is arranged on the mold (hereinafter, label arrangement stage). FIG. 7 shows an enlarged view of a portion corresponding to the corner of FIG. FIG. 8 is a layout view of a mold apparatus for forming a container according to the present embodiment, and shows a stage where label placement and mold placement are completed and molten resin is filled (hereinafter, filling stage). FIG. 9 is a layout view of a mold apparatus for forming a container according to the present embodiment, and shows a state where a container is formed after filling with molten resin (hereinafter, a completion stage). FIG. 10A is an enlarged view of C2 in FIG. 8, and FIG. 10B is an enlarged view of C3 in FIG. FIG. 11 is a cross-sectional view taken along the line A-A ′ of FIG. 9 at the completion stage.

As shown in FIG. 6, the in-mold label 8 is arranged on the mold surface of the fixed mold 11 corresponding to the outer peripheral wall of the body portion 3 so that a part of the in-mold label 8 protrudes upward by the width of the flange. Although not shown in FIG. 6, the in-mold label 8 is held by vacuum, for example. Thereafter, the moving mold 10 is moved in the direction of the arrow in FIG.
6 to 11, the in-mold label 8 is expanded and deformed by using the injection pressure of the molten resin. However, the in-mold label 8 is expanded and deformed in advance using a dedicated jig (the in-mold label 8 is deformed so as to be in contact with the mold surface of the fixed mold 11 while lying down as shown in FIG. 10B). There is also a method of holding from the fixed mold 11 by vacuum.
In this case, before placing the movable mold 10, the in-mold label 8 is expanded and deformed using the above-described dedicated jig, and then held in the fixed mold 11 by vacuum.

As shown in FIG. 7, the corner portion 5 has a circular arc surface formed on the outer corner portion 5 b in the moving mold 10, and a circle formed on the inner corner portion 5 a in the fixed mold 11. An isolated mold surface is formed.
The arcuate surface having a radius of curvature R formed on the outer corner 5b acts to bend the upper edge of the in-mold label outward when the movable mold 11 is moved. Further, as described above, the radius of curvature r of the arcuate surface formed at the inner corner 5a is an arcuate surface having such a curvature that the in-mold label 8 is easily expanded and deformed along the lower surface of the flange 4. Is formed. It should be noted that the radius of curvature R of the arcuate surface formed at the outer corner portion 5b and the radius of curvature r of the arcuate surface formed at the inner corner portion 5a do not necessarily match.

  In FIG. 7, when the movable mold 11 moves, the upper end portion of the in-mold label 8 comes into contact with the mold surface of the outer corner portion 5b of the movable mold 11, and the in-mold label 8 is bent outward ( FIG. 7A, direction of arrow A). If the movable mold 11 is further moved (in the direction of arrow A in FIG. 7B), the in-mold label 8 is also bent outward in accordance with the movement of the movable mold 11. At this time, as described above, the fixed mold 11 has the arc surface of the arcuate surface formed at the inner corner portion 5a, so that the in-mold label 8 is fixed to the arc surface formed at the inner corner portion 5a. It can be bent without difficulty along the mold surface of the mold 11. Therefore, in a state where the mold arrangement is completed, the in-mold label 8 is bent outward as shown in FIG. 8 and the upper end edge comes into contact with the movable mold 11.

As shown in FIG. 8, in the state where the in-mold label 8, the moving mold 10 and the fixed mold 11 are arranged, the molten resin is supplied from the gate 12 opened on the mold surface of the fixed mold 11 at the bottom central portion of the container body 2. Eject.
This molten resin flows from the portion corresponding to the bottom portion 7 of the cavity toward the portion corresponding to the flange 4 through the portion corresponding to the body portion 3 side peripheral wall. After completing the filling (FIG. 9), the mold is released after cooling and solidification. Thereby, the cup-shaped container 1 with the in-mold label of a present Example is obtained.

As shown in FIG. 10A, a part of the in-mold label 8 provided on the flange 4 is pressed against the mold surface of the fixed mold 11 corresponding to the lower surface of the flange 4 by the injection pressure of the molten resin (FIG. 10 ( a), pressed in the direction of arrow c).
The in-mold label 8 has an extensibility that can be expanded and deformed along the lower surface of the flange 4. Further, an arc surface having a radius of curvature r that is easily expanded and deformed along the lower surface of the flange 4 is provided on the mold surface of the fixed mold 11 in the inner corner portion 5a.
Therefore, when receiving the injection pressure of the molten resin, the mold surface of the fixed mold 11 at the inner corner portion 5a serves as a guide, and the in-mold label 8 is bent or bent when performing the above-described expansion and extension deformation. The label portion provided in the inner corner portion 5a can be smoothly curved.

FIG. 11 shows a cross-sectional view of the AA ′ cross section of FIG. 9 at the completion stage.
A label layer 8b having a function as a reinforcing member is strongly bonded to the flange 4 by thermal welding via the adhesive layer 8a. Further, the surface layer 8c having a function of protecting the label layer 8b is strongly bonded by thermal welding at the contact portion (P1 and P2) with the flange 4 at the seam 9 of the label.

As described above, the in-mold label 8 and the flange 4 constitute a reinforced flange 4a as the entire flange portion of the cup-shaped container 1. In this reinforced flange 4a, since the in-mold label 8 having a function as a reinforcing member is provided on the entire lower surface of the flange 4, the reinforced flange 4a, which is the flange portion of the cup-shaped container 1, covers the entire surface. It is reinforced by the in-mold label 8. Further, since the upper edge of the in-mold label 8 is at the outer peripheral edge of the flange 4, there is no thickness change portion formed by the contact portion between the upper edge of the in-mold label 8 and the flange 4. Can also be suppressed.
Even if the seam 9 of the label is formed, the contact portion (P1, P2) between the surface layer 8c of the in-mold label 8 and the flange 4 is strongly thermally welded as described above, so that cracks are not generated. Suppressed. Accordingly, the reinforced flange 4a has a structure that is strong and hardly cracks.
Thus, since the flange part of a structure stronger than the flange part of the conventional cup-shaped container is realizable, in the cup-shaped container 1 of the said Example, it is also possible to make it thinner.

Although the embodiment of the present invention and the operation and effect thereof have been described along the above-described examples, the present invention is not limited to these examples.

As described above, the present invention can realize a cup-shaped container with an in-mold label having a flange that is structurally strong against a pressing load from above.
For this reason, since a structurally stronger container can be realized, a thinner and lighter container can be expected. Therefore, the cup container with an in-mold label according to the present invention can be expected to be used widely for foods and the like.

DESCRIPTION OF SYMBOLS 1; Cup-shaped container 2; Container main body 3; Body part 4; Flange 4a; Strengthening flange 5; Corner part 5a; Inner corner part 5b; Outer corner part 6; Leg part 7; Bottom part 8; Label layer 8c; surface layer 9; label seam 10; moving mold 11; fixed mold 12; gate

Claims (2)

An injection-molded container body (2) having a bottomed cylindrical body (3) and an outer flange-like flange (4) connected to the opening of the body (3), and a reinforcing member A synthetic resin cup-shaped container composed of an in-mold label (8) having a function as
The in-mold label (8) is provided continuously from the body (3) to the outer peripheral end of the lower surface of the flange (4), and has an extensibility capable of expanding and deforming along the lower surface of the flange (4). And
The in-mold label (8) has a corner portion (5) that is a boundary portion between the body portion (3) and the flange (4) so that the diameter of the in-mold label (8) is easily expanded and deformed along the lower surface of the flange (4). Forming an arc surface having a curvature at the inner corner (5a) of
The in-mold label (8) has a label layer (8b) having a function as a reinforcing member, an adhesive layer (8a) that strongly bonds the label layer (8b) and the container body (2) by heat welding, and It comprises a surface layer (8c) that protects the label layer (8b),
A synthetic resin cup-shaped container, wherein the surface layer (8c) is formed of a material compatible with the resin material constituting the container body (2). The synthetic resin cup-shaped container according to claim 1, wherein the in-mold label (8) is provided from the lower end edge of the outer peripheral surface of the body portion (3).

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