Labeled container and method for manufacturing labeled container

Abstract

To provide a labeled container and a method for manufacturing the labeled container, in which a label made by shrinking a heat-shrinkable film is attached, and in which when a part of the label attached to the container body is cut out, the cut edge does not rise up from the container body.SOLUTION: An empty container body 1a is preheated so that the surface temperature of a body 3 reaches 55 to 65°C, and then a cylindrical heat-shrinkable film is placed over the body 3 of the container body 1a. The heat-shrinkable film is then heat-shrunk in an oven set to a temperature of 60 to 150°C. Residual heat remaining in the container body 1a after it is removed from the oven is applied to the inner surface of the heat-shrinkable film so that the residual shrinkage rate along the circumferential direction of a label L attached to the container body 1a is suppressed to less than 48%. Meanwhile, the outer surface of the heat-shrinkable film is cooled so that a part of the label L attached to the container body 1 is to be cut out.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a labeled container and a method for manufacturing a labeled container. [Background technology]

[0002] For example, Patent Document 1 discloses a bottle with a shrink sleeve, which includes a handle disposed on the side of the bottle, and the bottle is provided with a shrink sleeve, but the sleeve does not cover the handle. Paragraph

[0017] of Patent Document 1 states, "In such an embodiment, it is preferable to cut off the sleeve on the bottle after performing the heat shrinking operation." [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2003-509298 Summary of the Invention [Problem to be solved by the invention]

[0004] However, if the sleeve is cut off on the bottle after the heat shrinking process has been performed, the cut edge of the sleeve may rise up, marring the appearance, or may come into contact with the user's hand, causing discomfort.

[0005] In view of this background technology, the inventors of the present invention have conducted extensive research into how to prevent the cut edge of a label attached to a labeled container, which has a label made by shrinking a heat-shrinkable film, from floating up from the container body when cutting out a portion of the label attached to the container body, and as a result have completed the present invention. [Means for solving the problem]

[0006] The labeled container of the present invention is a labeled container having a label attached thereto by shrinking a heat-shrinkable film before filling the contents into a container body blow-molded into a predetermined container shape, and has a label cutout portion in which a portion of the label is cut out, and is configured so that the residual shrinkage rate along the circumferential direction of the label is less than 48%.

[0007] In addition, the method for manufacturing a labeled container according to the present invention is a method for manufacturing a labeled container having a label attached thereto by shrinking a heat-shrinkable film before filling a container body that has been blow-molded into a predetermined container shape with contents, in which the method involves preheating the body of the container body so that the surface temperature of the body is 55 to 65°C, covering the body of the container body with the tubular heat-shrinkable film, and then heat-shrinking the heat-shrinkable film in an oven set at a temperature of 60 to 150°C, and cooling the outer surface of the heat-shrinkable film while applying residual heat remaining in the container body after being removed from the oven to the inner surface of the heat-shrinkable film so that the residual shrinkage rate along the circumferential direction of the label attached to the container body is suppressed to less than 48%, thereby cutting out a portion of the label attached to the container body. [Effects of the Invention]

[0008] According to the present invention, in a labeled container to which a label made by shrinking a heat-shrinkable film is attached, when cutting out a portion of the label attached to the container body, the cut edge can be prevented from floating up from the container body. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is a front view showing an outline of a labeled container according to an embodiment of the present invention. [Figure 2] 2 is a cross-sectional view taken along the line AA in FIG. 1. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.

[0011] Fig. 1 is a front view showing a schematic diagram of a labeled container according to this embodiment, and Fig. 2 is a cross-sectional view taken along line AA in Fig. 1. The labeled container 1 shown as an example in these figures has a container body 1a blow-molded into a predetermined container shape having a mouth 2, a body 3, and a bottom 4, and a label L made by shrinking a heat-shrinkable film is attached to the empty container body 1a after blow-molding before filling it with contents. In FIG. 1, the label L is indicated by a broken line, and in FIG. 2, the label L is omitted.

[0012] The container body 1a can be molded by so-called direct blow molding, in which, for example, a resin material melted and kneaded in an extruder is extruded through an annular die, the resulting cylindrical parison is sandwiched between a pair of split dies, and air is blown into the parison to perform blow molding. In this process, predetermined radially opposing portions of the parison are partially crushed and fused together to form a recess 5 that is deeply recessed relative to the surrounding area and includes a through-hole 6, thereby providing a gripping handle 7 as shown in the figure on the body 3.

[0013] The resin material used for blow molding the container body 1a is preferably, but not limited to, an ethylene-based resin such as low-density polyethylene, linear low-density polyethylene, or high-density polyethylene, or an olefin-based resin such as polypropylene, a propylene-ethylene random copolymer, a propylene-ethylene block copolymer, or a copolymer of propylene and an α-olefin other than propylene, or a mixture thereof. The container body 1a is not limited to a single-layer structure, but may also have a laminate structure formed by laminating multiple layers made of different or the same type of resin material.

[0014] The heat-shrinkable film used for the label L attached to such a container body 1a may be a heat-shrinkable film made from a polystyrene resin, a polyester resin, a polyvinyl chloride resin, a polypropylene resin, a polyethylene resin, or a mixture thereof, formed by a T-die method, an inflation method, etc. Among these, it is preferable to use a heat-shrinkable film containing a polystyrene resin as a main component, which can increase the shrinkage rate.

[0015] The heat-shrinkable film for the label L may be single-layer or multi-layer, as long as the entire film has heat-shrinkability. When the heat-shrinkable film is multi-layered, for example, a layer made of a polyester resin may be laminated on one or both sides of a layer made of a polystyrene resin in order to improve heat resistance, blocking resistance, solvent resistance, etc. Furthermore, the heat-shrinkable film may be provided with a printed layer for product display, design pattern, etc.

[0016] Examples of polystyrene-based resins that can be used include homopolymers of styrene derivatives such as styrene and α-methylstyrene, copolymers thereof, styrene-conjugated diene copolymers such as styrene-butadiene copolymers and styrene-isoprene copolymers, rubber-modified impact-resistant polystyrene, and mixtures thereof. Examples of polyester-based resins that can be used include polyester-based resins obtained by copolymerizing a dicarboxylic acid component such as terephthalic acid with a diol component such as ethylene glycol, 1,4-cyclohexanedimethanol, or neopentylglycol.

[0017] The heat-shrinkable film for the label L preferably has a shrinkage percentage of 46.5% or more in the main shrinkage direction and a shrinkage percentage of 1% or less in the direction perpendicular to the main shrinkage direction. By adjusting the shrinkage percentage of the heat-shrinkable film in this manner, it is possible to effectively prevent wrinkles and distortion of the print when attaching the label L.

[0018] Here, the shrinkage rate of the heat-shrinkable film for label L is determined by cutting a sample piece of a predetermined size (for example, length: 50 mm x width: 50 mm) from the heat-shrinkable film and immersing it in warm water at 70°C for 10 seconds, and determining the amount of shrinkage. The shrinkage rate is a value calculated from the following formula (1), where L0 is the length of the sample piece before shrinkage along the main shrinkage direction or a direction perpendicular thereto, and L1 is the length of the sample piece after shrinkage. ((L0-L1) / L0)×100(%) ··· (1)

[0019] The heat-shrinkable film for the label L can be prepared in advance by, for example, unwinding a roll of the heat-shrinkable film, bonding both ends of the film together so that the main shrinkage direction is the circumferential direction, and then cutting the film to a predetermined length. When forming the heat-shrinkable film into a cylindrical shape, the circumferential length can be adjusted appropriately depending on the shrinkage rate in the main shrinkage direction and the maximum circumferential length of the barrel 3 of the container body 1a, and is preferably, for example, about 1.02 to 1.10 times the maximum circumferential length of the barrel 3 of the container body 1a.

[0020] To attach the label L to the container body 1a, the body 3 of the container body 1a is first preheated to a surface temperature of 55 to 65°C. To preheat the body 3 of the container body 1a, for example, it is sufficient to heat the entire container body 1a in an oven so that the temperature is uniform throughout, but preheating here also refers to slowly cooling the container body 1a immediately after blow molding to reach the above temperature. In either case, it is preferable that the entire container body 1a be at a uniform temperature.

[0021] The body 3 of the container body 1a thus preheated is covered with a cylindrical heat-shrinkable film for the label L, and then the heat-shrinkable film is heat-shrunk in an oven set at a temperature of 60 to 150°C to adhere to the body 3 of the container body 1a. The treatment time in the oven is preferably about 15 to 30 seconds. The surface temperature of the body 3 of the container body 1a in the oven is preferably 72 to 78°C. When heat-shrinking the heat-shrinkable film, the empty container body 1a is preheated, and then the heat-shrinkable film is placed over the body 3 and heated, allowing the heat-shrinkable film to shrink well.

[0022] After the heat-shrinkable film is thermally shrunk by this heat treatment process and adhered to the barrel portion 3 of the container body 1a, the container body 1a is removed from the oven and cooled. At this time, the outer surface of the heat-shrinkable film is cooled while applying residual heat remaining in the container body 1a after being removed from the oven to the inner surface of the heat-shrinkable film so that the residual shrinkage rate along the circumferential direction of the label L attached to the container body 1a is suppressed to less than 48%.

[0023] Here, the residual shrinkage of the label L is defined as a value indicating the shrinkability remaining in the heat-shrinkable film used for the label L even after it has been attached to the container body 1a. The residual shrinkage is determined by cutting a sample piece of a predetermined size (e.g., length: 50 mm × width: 50 mm) from the label L attached to the container body 1a after the manufactured labeled container 1 has been allowed to cool for a sufficient amount of time, and immersing the sample piece in warm water at 70°C for 10 seconds, and determining the amount of shrinkage. The residual shrinkage is a value calculated from the following formula (2), where L2 is the length of the sample piece before shrinkage along the direction corresponding to the circumferential direction when attached to the container body 1a, and L3 is the length of the sample piece after shrinkage. ((L2-L3) / L2)×100(%) ··· (2)

[0024] When cooling the outer surface side of the heat-shrinkable film, it is preferable to cool it with cooled air, and the temperature of the cooled air is preferably set to about 20° C. or less. Specific means for cooling with cooled air are not particularly limited, but for example, cooled air can be ejected from the outlet of a pipe arranged along the conveying path leading to the outlet of the oven, thereby cooling the film while conveying it. It is preferable to provide a tunnel-shaped cover with an open bottom or top side in the conveying path so that the flow of cooled air can be controlled, thereby increasing cooling efficiency.

[0025] In this embodiment, by cutting out a portion of the label L attached to the container body 1a after the cooling process, it is possible to prevent the cut edge from lifting up from the container body 1a. The reason for this is thought to be as follows: One of the reasons why the cut edge of the label L lifts up from the container body 1a is thought to be that the shrinkage amount of the container body 1a is greater than the shrinkage amount of the label L. However, by going through the cooling process as described above, it is thought that the shrinkage of the container body 1a can be prevented, and as a result, it is thought that the cut edge of the label L can be prevented from lifting up from the container body 1a.

[0026] In the illustrated example, a label cutout 8, in which a portion of the label L has been cut out, is cut out along the periphery of the recess 5 formed in the barrel 3 of the container body 1a. To cut out the label cutout 8 in this manner, for example, a cutting die having a cutting blade disposed along the outline of the label cutout 8 may be used, but it is preferable to cut it out with a laser.

[0027] If the temperature of the label L remains high when cutting out the label L with a laser, the heat from the laser irradiation will cause the cut edge to shrink unevenly, which may also cause the cut edge to lift up. In contrast, in this embodiment, the heat-shrinkable film used for the label L is heat-shrunk at a relatively low temperature in the heat treatment step described above, which allows the label L to be sufficiently cooled in the subsequent cooling step, making it less likely that such a problem will occur.

[0028] Furthermore, when the heat-shrinkable film is thermally shrunk to adhere to the barrel portion 3 of the container body 1a, it is preferable to apply a heat-sensitive adhesive to a portion of the inner surface of the heat-shrinkable film so that the film is temporarily fixed to the container body 1a before heat-shrinking. The heat-sensitive adhesive may be applied to both the upper and lower edges of the heat-shrinkable film covering the container body 1a. However, if the shrinkage of the container body 1a is even slightly greater than the shrinkage of the label L, the label L may flex in response to the shrinkage of the container body 1a. To effectively avoid such a problem, it is preferable to apply the heat-sensitive adhesive to either the upper or lower edge of the heat-shrinkable film covering the container body 1a.

[0029] The labeled container 1 thus manufactured is sent to a filling process, where it is filled with the contents, sealed, and then put on the market.

[0030] The present invention has been described above by showing preferred embodiments, but it goes without saying that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

[0031] For example, in the illustrated example, the recessed portion 5 is formed to include the through-hole 6, and the gripping handle 7 is provided on the body 3, but the recessed portion 5 may be formed so as not to include the through-hole 6. In this case, the recessed portion 5 can be formed to function as a gripping portion into which the user inserts their fingertips to grip the labeled container 1. [Explanation of symbols]

[0032] 1 labeled container 1a Container body 3. Torso 5. Recess 8 Label cutout L Label

Claims

1. A labeled container in which a label is attached by shrinking a heat-shrinkable film before filling a container body blow-molded into a predetermined container shape, a label cutout portion is provided in which a part of the label is cut out, A labeled container, characterized in that the residual shrinkage rate of the label along the circumferential direction is less than 48%.

2. 2. The labeled container according to claim 1, wherein the barrel of the container body has a recessed portion recessed from the surrounding area, and the label cutout portion is cut out along the periphery of the recessed portion.

3. A method for manufacturing a labeled container in which a label is attached by shrinking a heat-shrinkable film before filling a container body blow-molded into a predetermined container shape, the method comprising: The body of the container body is preheated to a surface temperature of 55 to 65°C, and then the cylindrical heat-shrinkable film is placed on the body of the container body. The heat-shrinkable film is heat-shrunk in an oven set at a temperature of 60 to 150°C. cooling the outer surface side of the heat-shrinkable film while applying residual heat remaining in the container body after being removed from the oven to the inner surface side of the heat-shrinkable film so that the residual shrinkage rate along the circumferential direction of the label attached to the container body is suppressed to less than 48%; This method of manufacturing a labeled container is characterized by cutting out a portion of the label attached to the container body.

4. The method for manufacturing a labeled container according to claim 3, wherein a portion of the heat-shrinkable film is cut out with a laser.

5. 5. The method for manufacturing a labeled container according to claim 3, wherein the outer surface of the heat-shrinkable film is cooled with cooled air.

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