JP5872149B2 - Container and container manufacturing method - Google Patents

Description

  The present invention relates to a container and a method for manufacturing the container.

  Food-related plastic containers are required to maintain the quality of food for a long time. Therefore, barrier property (barrier property is defined as having any one property or a plurality of properties of oxygen passage prevention property (gas barrier property), light shielding property, and water vapor passage prevention property; the same shall apply hereinafter). Development has been actively made (for example, see Patent Document 1).

  As an example of the container having improved barrier properties, a container in which a barrier label is in-molded around the side wall and the bottom of the plastic container can be cited. The barrier label is made of a laminated film such as an aluminum foil or a plastic film.

  FIG. 10 shows an example of a barrier container using a barrier label. Around the side wall 1a of the plastic container body 1, a barrier side wall label 2 is in-molded. And in order to improve the yield of the label of an in-mold, the thread bottom 1c is formed. In addition, the bottom label 3 having a barrier property is also in-molded on the bottom 1b.

  Since it is difficult to ensure barrier properties if there is a gap around the side wall 1a of the plastic container body 1 where the ends of the side wall label 2 face each other, the end of the side wall label 2 The overlapping portions 1d are provided by overlapping the portions.

JP 2006-27705 A

  However, since it is difficult to provide an overlapping portion between the side wall portion label 2 and the bottom portion label 3 between the side wall portion 1a and the bottom portion 1b of the plastic container main body 1, a barrier property is provided at the end portion of the yarn bottom 1c. It becomes difficult to ensure. That is, a gap is generated between the side wall label 2 and the bottom label 3, and the gap has no barrier property. In addition, the formation of the yarn bottom 1c limits the shape of the plastic container main body 1, and causes a sink near the yarn bottom 1c.

On the other hand, in the case of a container body that is a food-related plastic container and does not have a thread bottom, it is required to perform curved processing at the boundary between the side wall and the bottom. This is because the food remaining on the boundary between the side wall and the bottom can be scraped off with a spoon, a butter knife, a rice scoop or the like.
In the case of a plastic container body that does not have a yarn bottom, the barrier property can be secured by applying curved processing to the boundary between the side wall part and the bottom part and overlaying the side wall part label and the bottom part label. During the injection molding, wrinkles are generated in the bottom label due to the resin flow.

  This invention is made | formed in view of such a subject, and it aims at providing a novel container and the manufacturing method of a container.

  In order to solve the above problems and achieve the object of the present invention, the container of the present invention is a container in which a container main body, a side wall label, and a bottom label are integrally formed by injection molding, The label and the bottom label are formed of a single layer film, a double layer film, or a triple layer film.

  Further, the container main body is provided with a label positioning step having a width of 0.1 mm to 1.0 mm at the boundary between the side wall and the bottom.

  Further, the length of the label for the side wall portion is longer than the peripheral length of the side wall portion of the container body, and an overlapping portion of the label for the side wall portion is provided.

  Further, the size of the bottom label is made larger than the size of the bottom of the container main body, and an overlapping portion of the side wall label and the bottom label is provided.

  In order to solve the above problems and achieve the object of the present invention, a container manufacturing method of the present invention includes a container main body, a side wall label and a bottom formed of a single layer film, a double layer film, or a triple layer film. The product label is integrally formed by injection molding.

The present invention has the following effects.
The present invention is a container in which a container body and a label are integrally formed by injection molding, wherein the label is formed of a laminated film of one layer, two layers, or three layers, and one layer is formed of a base material containing polypropylene. Therefore, a novel container and a method for producing the container can be provided.

It is the perspective view which looked at an example of the container of the present invention from the bottom side. It is the side view and sectional view which looked at an example of the container of the present invention from the side wall part side. It is sectional drawing which looked at an example of the container of this invention from the opening side. It is another sectional view which looked at an example of the container of the present invention from the opening side. It is a top view which shows the adhesive bond layer of the label of the container of this invention. It is a figure which shows the manufacturing method of the container of this invention. It is an enlarged view of the process 1 of FIG. It is an enlarged view of the process 3 of FIG. It is an enlarged view of the process 5 of FIG. It is the partial cross section side view and top view which looked at an example of the conventional container from the side wall part side and the bottom part side.

Hereinafter, the form for inventing concerning a container is demonstrated.
First, the container will be described. FIG. 1 is a perspective view of an example of the container of the present invention viewed from the bottom side, FIG. 2 is a side view and a cross-sectional view of the example of the container of the present invention viewed from the side wall, and FIGS. It is sectional drawing which looked at an example of this container from the opening side. The container includes a container body 11, a side wall label 12, and a bottom label 13.

  The container body 11 has a substantially truncated cone shape. The container main body 11 includes a collar part, a side wall part 11a, and a bottom part 11b. A flange-shaped collar portion is provided around the opening of the container main body 11. The collar portion has a function of serving as a locking portion when the upper surface of the container is covered with a lid material, and to give rigidity to the container, or to be a gripping portion when supplying the container on the production line.

  The side wall portion 11 a constitutes a side surface portion of the container body 11. The lateral cross section of the side wall portion 11a has a substantially circular shape, and its size decreases as it goes from the opening portion to the bottom portion 11b. Therefore, the peripheral length of the cross section of the side wall portion 11a becomes shorter as it goes from the opening portion to the bottom portion 11b. On the outside of the side wall portion 11a, a side wall portion label 12 (described in detail later) is in-molded.

A step portion 11c necessary for positioning the side wall portion label 12 is provided at the boundary between the lower portion of the inner surface of the side wall portion 11a and the bottom portion 11b. On the cavity step portion 27a (see FIG. 6) provided on the inner wall of the cavity 27 of the mold 20 for forming the step portion 11c, the lower side in the longitudinal direction of the side wall portion label 12 abuts. 12 is positioned.

  The bottom part 11b has a substantially circular shape and is a part that supports the contents. A bottom label 13 (described in detail later) is in-molded outside the bottom portion 11b.

  In the curved surface formed at the boundary between the side wall and the bottom of the container main body, the curvature radius of the curved surface in the cross section of the container main body is preferably in the range of 10 to 30 mm. When the curvature radius is 10 mm or more, there is an advantage that the food remaining on the boundary between the side wall and the bottom can be scraped off with a spoon, a butter knife, a rice scoop or the like. There exists an advantage that the capacity | capacitance of a container main body can fully be ensured that a curvature radius is 30 mm or less.

  The shape of the container body 11 is not limited to the substantially truncated cone shape described above. In addition, a substantially rectangular parallelepiped shape, a substantially cylindrical shape, a substantially elliptical column shape, or the like can be employed.

  As a material of the container body 11, thermoplastic resins such as polyethylene (PE), polypropylene (PP), and polystyrene (PS) can be employed.

  Next, the side wall portion label 12 bonded to the side wall portion 11a and the bottom portion label 13 bonded to the bottom portion 11b will be described. As the barrier side wall label 12 and the bottom label 13, that is, a label having one or a plurality of properties of oxygen passage prevention property (gas barrier property), light shielding property, water vapor passage prevention property, It is preferable to use a film label, a two-layer film label composed of a surface layer and a back layer, or a three-layer film label composed of a surface layer, an intermediate layer and a back layer.

  Examples of the material for the single-layer film label include biaxially stretched polypropylene OPP. In addition, it is preferable that the film thickness of biaxially-stretched polypropylene OPP exists in the range of 20-35 micrometers.

  Examples of the material of the bilayer film label include biaxially stretched polypropylene OPP / heat-sealable biaxially stretched polypropylene film HSOPP. In addition, it is preferable that the film thickness of biaxially-stretched polypropylene OPP exists in the range of 20-35 micrometers. The film thickness of the heat-sealable biaxially stretched polypropylene film HSOPP is preferably in the range of 20 to 35 μm.

  Examples of the material of the three-layer film label include biaxially stretched polypropylene OPP / aluminum-deposited polyethylene terephthalate VMPET / heat-sealable biaxially stretched polypropylene film HSOPP. In addition, it is preferable that the film thickness of biaxially-stretched polypropylene OPP exists in the range of 20-35 micrometers. The film thickness of the heat-sealable biaxially stretched polypropylene film HSOPP is preferably in the range of 20 to 35 μm. The total film thickness of the three-layer film label is preferably in the range of 50 to 80 μm.

  To eliminate wrinkles on the bottom label 13, a single-layer film label, a two-layer film label composed of a surface layer and a back layer, and a three-layer film label composed of a surface layer, an intermediate layer and a back layer are used. Is possible.

  The display surface of the side wall portion label 12 is a design display portion such as characters and patterns formed on the surface of the side wall portion label 12. As a method for forming the display surface, methods such as gravure printing, offset printing, and relief printing can be employed.

  The upper end of the side wall portion label 12 can be made higher than the upper end of the side wall portion 11a, and the upper end of the side wall portion can be bent outward and bonded to the lower side of the collar portion.

  The length of the side wall portion label 12 in the longitudinal direction is longer than the peripheral length of the side wall portion 11 a of the container body 11. Thereby, the overlapping portion 12b where the end portions of the side wall portion label 12 overlap each other is formed. Thus, the barrier property of a container can be made more reliable by making the length of the longitudinal direction of the label 12 for side wall parts longer than the peripheral length of the side wall part 11a.

  The outer dimension of the bottom label 13 is made larger than the outer dimension of the bottom part 11b. As a result, an overlapping portion 13 b is formed in which the peripheral portion of the bottom portion label 13 overlaps the lower portion of the side wall portion label 12. Thus, by making the outer dimension of the bottom label 13 larger than the outer dimension of the bottom part 11b, the barrier property of the container can be further ensured. In the center of the bottom label 13, there is provided a hole 13c (see FIG. 5B) through which the molten resin passes when the container is injection-molded.

The width of the overlapping portions 12b and 13b is preferably in the range of 3 to 10 mm.
In the overlapping portions 12b and 13b, the adhesive layer 14 is provided between the outer side wall portion label 12 and the inner side wall portion label 12, and between the peripheral portion of the bottom portion label 13 and the lower portion of the side wall portion label 12. Is provided. As a material of the adhesive layer 14, a low temperature region adhesive or the like can be employed. When bonding by molding using a low temperature region adhesive, the remelting temperature of the adhesive layer 14 is preferably in the range of 40 to 90 ° C. The remelting temperature of the adhesive layer 14 is more preferably in the range of 50 to 80 ° C. When the remelting temperature of the adhesive layer 14 is 40 ° C. or higher, there is an advantage that an effective adhesive force is generated. When the remelting temperature of the adhesive layer 14 is 50 ° C. or higher, this effect becomes more remarkable. When the remelting temperature of the adhesive layer 14 is 90 ° C. or less, there is an advantage that deterioration of the adhesive layer 14 can be prevented and an effective adhesive force can be generated. When the remelting temperature of the adhesive layer 14 is 80 ° C. or less, this effect becomes more remarkable.

Examples of the low temperature region adhesive include an ethylene vinyl acetate copolymer (EVA) adhesive. Examples of the ethylene-vinyl acetate copolymer (EVA) -based adhesive include a hot lacquer heat sealant (MHS-3356, manufactured by Toyo Morton).
The thickness of the adhesive layer 14 is preferably in the range of 3 to 5 g / m ² .

  As contents to be stored in the container, foods such as margarine, butter and yogurt can be put.

Next, a method for manufacturing the container will be described.
For bonding the side wall label 12 itself, an adhesive layer 14 is provided at the end of the back surface shown in FIG. 5Aa, and an adhesive layer 14 is provided at the end of the display surface shown in FIG. 5Ab. Note that the adhesive layer 14 may be one of the end of the display surface and the end of the back surface.

  For bonding the side wall label 12 and the bottom label 13, an adhesive layer 14 is provided on the lower surface of the back surface of the side wall label 12 shown in FIG. 5Aa, and on the periphery of the surface of the bottom label 13 shown in FIG. 5B. An adhesive layer 14 is provided. The adhesive layer 14 may be one of the lower portion of the display surface of the side wall portion label 12 and the peripheral portion of the surface of the bottom portion label 13.

  As a method of forming the adhesive layer 14 on the display surface or back surface of the side wall label 12 and the surface of the bottom label 13, methods such as gravure coating and roll coating can be employed.

  Next, molding of the container will be described. The container integrally molds the container main body 11, the side wall label 12, and the bottom label 13 by injection molding. 6A and 7 show a mold 20 used for manufacturing a container. A cavity step portion 27 a for forming the step portion 11 c of the container body 11 is provided at the lower portion of the peripheral surface inside the cavity 27.

  As shown in FIG. 6B, in the injection molding, first, the side wall label 12 is loaded into the cavity 27, and the lower side in the longitudinal direction of the side wall label 12 is formed on the cavity step portion 27a for forming the step portion 11c. Position it in contact with. At this time, the end portions of the side wall portion label 12 overlap each other to form an overlapping portion 12b. Next, as shown in FIGS. 6C and 8, the bottom label 13 is bonded to the bottom surface of the core 29, and the mold is clamped as shown in FIG. 6D.

  Next, as shown in FIGS. 6E and 9, the molten thermoplastic resin is filled into the space formed between the cavity 27 and the core 29 through the nozzle 24. The molten resin R spreads between the core 29 and the bottom label 13 from the nozzle 24 through the hole 13c of the bottom label 13 and rises between the core 29 and the side wall label 12, as indicated by an arrow RF. To do. At this time, the peripheral portion of the bottom label 13 extends outward and is pulled, so that the wrinkles are extended. Finally, the peripheral portion of the bottom label 13 overlaps with the lower end portion of the side wall portion label 12 in the longitudinal direction. 13b is formed. The adhesive layer 14 of the bottom label 13 and the side wall label 12 is melted. Further, the adhesive layer 14 formed on the overlapping portion 12b of the side wall portion label 12 is melted.

  Next, as shown to FIG. 6F, a container is shape | molded by cooling a molded object. At this time, the adhesive layer 14 in the overlapping portion 12b of the side wall portion label 12 and the overlapping portion 13b of the bottom portion label 13 is solidified, and adhesion between the labels in the overlapping portions 12b and 13b is secured. Next, the core 29 is pulled out and further pushed out by the stripper 28, whereby the container is separated from the mold 20.

The width of the cavity step portion 27a is preferably in the range of 0.1 mm to 1.0 mm.
When the width of the cavity step portion is 0.1 mm or more, when the side wall label is loaded into the cavity, the lower side in the longitudinal direction of the side wall label can be brought into contact with the cavity step portion for positioning. There is an advantage.

  Further, when the molten thermoplastic resin is filled in the space formed between the cavity and the core, the molten resin is first filled and spread between the core and the bottom label. Thereafter, the peripheral edge portion of the bottom label is extended and pulled outward in the space formed in the cavity step portion. As a result, there is an advantage that the wrinkles at the peripheral edge of the bottom label are extended and the wrinkles disappear.

  Further, as described above, the molten resin is filled and spread between the core and the bottom label, and then the peripheral edge of the bottom label is extended and pulled outward in the space formed in the cavity step portion. . As a result, the wrinkles at the peripheral edge of the bottom label are extended. In the cavity step portion, a large space is formed between the bottom label and the core. The space between the bottom label and the core is larger than the space between the bottom label and the core in other portions. Thus, since a large space is formed between the bottom label and the core, more molten resin is present than between the bottom label and the core in other portions. The molten resin present here has a larger heat capacity than the molten resin present between the bottom label and the core of the other part. Thus, since it has a large heat capacity, the adhesive layer existing between the side wall label and the bottom label can be more reliably melted. As a result, the side wall label and the bottom label There is an advantage that adhesion is improved.

  On the other hand, when the width of the cavity step portion is 1.0 mm or less, the step portion of the container main body is inconspicuous, and there is an advantage that the appearance of the container can be kept beautiful.

  The cavity step portion 27a may not be provided. By using the above-mentioned label material, the yield is reduced as compared with the case where the cavity stepped portion 27a is provided, but the wrinkle generation rate of the bottom label 13 is sufficiently reduced as compared with the conventional manufacturing method. Can do.

  When formed by the above-described method, since the bottom label 13 has the hole 13c, the hole 13c has no barrier property. However, since the area of the hole 13c of the bottom label 13 of the container of the present invention is smaller than the clearance area between the side wall label 12 and the bottom label 13 of the conventional container, The barrier property of a container improves compared with the conventional container. The nozzle 24 provided in the cavity 27 may be provided in the core 29. In this case, since no hole is formed in the bottom label 13, the barrier property of the container becomes perfect.

  From the above, according to the embodiment for carrying out the present invention, the container body 11, the side wall label 12, and the bottom label 13 are integrally molded by injection molding, Since the bottom label 13 is a laminated film of one layer, two layers, or three layers, and one layer is formed of a base material containing polypropylene, a novel container can be provided. Since the container of the present invention does not need to form a yarn bottom, the degree of freedom in design of the container shape is greatly improved.

  The present invention is not limited to the best mode for carrying out the above-described invention, and various other configurations can be adopted without departing from the gist of the present invention.

DESCRIPTION OF SYMBOLS 11 ... Container body, 11a ... Side wall part, 11b ... Bottom part, 11c ... Step part, 12 ... Label for side wall part, 13 ... Label for bottom part, 12a ... Display surface, 12b, 13b ... Overlapping , 12c ... Back side, 14 ... Adhesive layer, 20 ... Mold, 24 ... Nozzle, 27 ... Cavity, 27a ... Cavity step, 28 ... Stripper, 29 ... Core

Claims (3)

A container comprising a container body and the side wall portion label and the bottom label,
The container is an injection molded body,
The container is an in-mold molded body comprising the container body, the side wall part label, and the bottom part label,
The side wall label and the bottom label are composed of a single layer film, a two layer film, or a three layer film,
The container body has a side wall and a bottom,
The container body is provided with a stepped portion with a predetermined width at the boundary between the side wall and the bottom,
Outside the side wall, the side wall label is present ,
The lower side of the label for the side wall portion is located at the stepped portion,
On the outside of the outer and the stepped portion of said bottom, said bottom label is present,
The outer dimensions of the bottom label is, the rather larger than outer dimensions of the bottom, overlapped portions of the bottom label and the side wall portion label is provided,
The overlapping portion exists in the side wall portion,
The container according to claim 1, wherein a peripheral portion of the bottom portion label is present inside the side wall portion label. The length of the label for the side wall portion, the container body of the rather long than the surrounding length of the side wall, the container of claim 1, wherein superimposing section of the label side wall portion, characterized in Rukoto provided. A method for manufacturing a container, comprising integrally forming a container body, a side wall label and a bottom label formed of a one-layer film, a two-layer film, or a three-layer film by injection molding,
The container body has a side wall and a bottom,
The side wall part label is in-molded outside the side wall part,
The bottom label is in-molded on the outside of the bottom,
The bottom dimension of the bottom label is larger than the bottom dimension,
The injection molding uses a mold having a cavity and a core,
The injection molding includes a step of loading the side wall part label into the cavity, bonding the bottom part label to the bottom surface of the core, and clamping the mold.

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