JPH0585417B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a method for manufacturing labeled containers in which a heat-shrinkable foamed resin sheet label is tightly wrapped around a thermoplastic resin container.

[Conventional technology]

Printing on thermoplastic resin containers (hereinafter simply referred to as containers) can be done either by partial printing on the container, especially on the flat surface, or by simple printing, such as on bowl-shaped containers for instant cup noodles. Only designs can be executed.

In addition, films or sheets that shrink when heated are used as packaging materials for containers, but when any film or sheet is heated and shrunk, irregular distortions occur during shrinkage, which can cause problems even if the design is misaligned. Currently, it can only be used in cases where there is no.

Furthermore, although containers for microwave ovens have been developed in recent years, there have been no containers that are held directly in the hand and have printed markings or the like. In addition, there is the problem that containers that have just been cooked in a microwave oven are too hot to hold with bare hands. It has been desired to develop a container with a printing on it.

[Problem that the invention seeks to solve]

The present invention has been made based on the above-mentioned viewpoints, and its object is to provide an inexpensive and extremely high commercial value product by wrapping a heat-shrinkable label having heat insulation properties around a predetermined position of a container. An object of the present invention is to provide a method for manufacturing a container with a shrink label.

[Means for solving problems]

The above object is, in a method for manufacturing a container with a shrink label, in which a thermoplastic resin container is inserted inside a sleeve-shaped label made of a foamed resin sheet that heat shrinks in a uniaxial direction, and the label is heat-shrinked. A flange is formed at the opening of the thermoplastic resin container, the flange is bent toward the label, and the label is heat-shrinked while one peripheral edge of the label is held down by the bent portion and the outer peripheral wall surface of the container. This can be achieved by a method for producing a container with a shrink label, which is characterized by the following.

It is recommended that the foamed resin sheet is a foamed polystyrene sheet with a thickness of 0.07 to 1.0 mm and an expansion ratio of 1.5 to 10.0 times.

[Effect]

By configuring as described above, one peripheral edge of the heat-shrinkable label having heat insulating properties is held in a fixed position by being sandwiched between the outer peripheral wall surface of the container and the bent part of the flange. Since it can be wrapped reliably in the desired position, labeled containers with high commercial value can be provided at low cost.

〔Example〕

Hereinafter, the details of the present invention will be specifically explained with reference to the drawings.

FIG. 1 is an explanatory diagram showing a state in which a label made of a foamed resin sheet used for a labeled container according to the present invention is formed into a sleeve shape, and FIG. An explanatory diagram showing a state in which the container is inserted; FIGS. 3 to 5 are enlarged cross-sectional views showing different bent shapes of the flange of the container; FIG. 6 is a preferred embodiment of the flange of the container before it is bent. FIG. 7 is a partial sectional view showing the completed state of one embodiment of the shrink-labeled container according to the present invention.

In Figures 1 to 7, 1 is a label made of a foamed resin sheet with desired printing, etc., 1a is a joint thereof, 2 is a container made of thermoplastic resin, 2
a is a flange portion of a container made of the above-mentioned thermoplastic resin container.

Foamed sheet labels in the present invention include foamed polystyrene labels, foamed polyolefin labels, and the like, which have the ability to shrink significantly in a uniaxial direction when heated. The heat shrinkage performance of labels is measured by the shrinkage rate when immersed in oil at 120℃ for 1 minute, and is 20 to 70% in the circumferential direction of the container.
%, -15 to 15% in the height direction of the container (- indicates elongation).

For example, a foamed polystyrene label is a resin made by copolymerizing styrene with general-purpose polystyrene, butadiene, acrylonitrile, methacrylic acid, acrylic acid, maleic anhydride, etc., and a blowing agent, such as carbon dioxide gas or nitrogen gas. Adding 0.05 to 3.0% by weight of a chemical blowing agent generated by thermal decomposition to the resin, or adding a low boiling point organic solvent such as hydrocarbon compounds such as butane and pentane or hydrofluoric compounds such as Freon 11, 12, and 114 to the resin. 0.001~0.07 for
After injecting into the middle of the mole extruder and plasticizing and mixing,
It is composed of a sheet with a cell structure produced by releasing it into the atmosphere, and can be used alone or together with the foamed polystyrene sheet and polystyrene resin, high-density polyethylene, low-density polyethylene, polypropylene, or ethylene-vinyl acetate. This is a printed sheet laminated with a film made from a raw material mixed with a polyfin resin such as a polymer.

The appropriate thickness of the label is 0.07 to 1.0 mm.
The expansion ratio is usually 5 to 10.0 times, preferably 0.1 to 0.6 mm and 1.7 to 8 times, respectively.

If the thickness of the label 1 is less than 0.07 mm, the heat insulation properties will be insufficient and the label 1 will be bent when inserted into the container 2. On the other hand, if the thickness of the label 1 exceeds 1.0 mm, it will be difficult to create a sleeve. The difference in curvature between the inner and outer surfaces of the label increases, causing wrinkles on the surface.

If the expansion ratio is less than 5 times, the thermal conductivity will increase and the heat insulation properties of the container 2 will decrease. On the other hand, if the expansion ratio exceeds 10 times, secondary foaming will be large during heat shrinkage, making it impossible to attach the label 1 to a predetermined position on the container 2.

In the present invention, first, as shown in FIG. 1, the end surfaces of a flat label 1 made of expanded polystyrene are joined by heat sealing or adhesive to form a joint 1a, and then a cylindrical sleeve is formed. form.

Next, as shown in FIG. 2, a container 2 made of thermoplastic resin is inserted into the sleeve-shaped label 1 until the end surface of the label 1 contacts the flange 2a.

The container 2 made of thermoplastic resin is a sheet obtained by extruding a resin heated and melted in an extruder through a mold slit attached to the tip of the extruder. There are no particular restrictions on the material of the container, as long as it is a container that is fabricated by secondary processing or molded using an injection molding machine, and is compatible with the above-mentioned molding method. Examples include polypropylene, polystyrene, polystyrene terephthalate, polycarbonate, polyamide, polystyrene, etc., but preferably a resin with a heat distortion temperature (JIS K-6871) exceeding 100°C. If this cannot be achieved by itself, it can be used as a laminate with a resin that has a high heat deformation temperature.

The flange 2a of the thermoplastic resin container 2 is bent by an external force until the label is suppressed after the sleeve-shaped label 1 is inserted along the outer wall of the container until it reaches the flange, or before the label 1 is inserted. It is bent by an external force. Preferably, after inserting the label 1 into the container 2, the flange 2a is bent by external force.

There are no particular restrictions on the shape of the flange 2a after it is bent, but as shown in FIGS. 3 to 5,
Some have a flat opening surface and others have rounded flanges. Further, in order to make the flange 2a easier to bend, it is preferable to provide grooves or cuts 2b, 2b as shown in FIG. 6 before bending.

Therefore, when the label 1 formed in a sleeve shape is placed in a heating furnace while being held down by the flange 2a of the container 2 and is heated and shrunk, the outer circumferential wall surface of the container 2 will not be misaligned when the label shrinks. The label 1 is wrapped around a predetermined position.

In FIG. 6, grooves 2 are provided in the flange portion 2a in advance.
An example of a container with b and 2b is shown. Second
After inserting the sleeve as shown in the figure, mechanically caulk the flange while heating it to 50 to 100℃.
Forcibly bend the flange 2a and attach the label 1 to the container 2.
It is clamped between the outer peripheral wall of.

Then, the container 2 with the foamed polystyrene label 1 inserted therein was turned upside down, and heated to 180°C.
By heating and shrinking the label 1 by placing it in a heating oven for 3 to 30 seconds, the end surface of the label 1 shrinks without shifting from the container 2, and the label 1 is firmly attached to the predetermined position of the container 2 as shown in FIG. can be done.

〔Effect of the invention〕

Since the present invention is configured as described above, when the present invention is used, a heat-shrinkable label having heat insulating properties can be reliably wrapped around a predetermined position of a thermoplastic resin container. In addition, labeled containers are not only aesthetically pleasing but also have excellent heat insulation properties, and heat-resistant resin containers are suitable for use in microwave ovens, and further, their strength is increased in containers with thin outer walls.

It should be noted that the present invention is not limited to the embodiments described above, and the design can be changed freely within the scope of the purpose, and the present invention can be modified easily by a person skilled in the art from the embodiments described above. It is intended to include all modifications as may be obtained.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing a state in which a label made of a foamed resin sheet used for a labeled container according to the present invention is formed into a sleeve shape, and FIG. An explanatory diagram showing a state in which the container is inserted; FIGS. 3 to 5 are enlarged cross-sectional views showing different bent shapes of the flange of the container; FIG. 6 is a preferred embodiment of the flange of the container before it is bent. FIG. 7 is a partial sectional view showing the completed state of one embodiment of the shrink-labeled container according to the present invention. 1...Label of foamed resin sheet, 1a...Joint part, 2...Container, 2a...Flange.

Claims (1)

[Scope of Claims] 1. A method for manufacturing a container with a shrinkable label, in which a thermoplastic resin container is inserted into a sleeve-shaped label made of a foamed resin sheet that heat-shrinks in a uniaxial direction, and the label is heat-shrinked, comprising: A flange is formed at the opening of the resin container, the flange is bent toward the label, and the label is heat-shrinked while one peripheral edge of the label is held down by the bent portion and the outer peripheral wall surface of the container. A method for producing a container with a characteristic shrink label. 2. The method for producing a container with a shrink label according to claim 1, wherein the foamed resin sheet is a foamed polystyrene sheet having a thickness of 0.07 to 1.0 mm and an expansion ratio of 1.5 to 10.0 times.