JPH01240473A - Manufacture of labeled container - Google Patents

Abstract

PURPOSE:To obtain a container having high commercial value at low cost by a method wherein an expanded polystyrene sheet having heat shrinkability is wound around the container of a specific shape. CONSTITUTION:A label 1 made of expanded polystyrene which heat-shrinks in a mono-axial direction, with thickness of approx. 0.1 to 1.0mm and expansion magnification of approx. 2 to 10 times is formed in a sleeve shape. A container 2 is formed so that a flange 2a is provided on an opening 2, an outer circumfer ence A in contact with the flange 2a is smaller than the maximum circumference B by approx. 0.1 to 30% and at the same time a distance C from a portion 2c on the maximum circumference to the flange 2a is at least 1% or more of a height D of the container 2. After the label 1 formed in a sleeve shape is inserted into the container 2 and heat-shrunk in a heating furnace, the label 1 is wound around at a specific position on the outer wall of the container 2. This container with a label is excellent not only in appearance but also heat insulation, serving as a suitable container for use in a microwave oven or the like.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application] The present invention relates to a method for manufacturing a container with a heat-shrinkable expanded polystyrene label.

[Conventional technology]

Printed markings on containers, such as thermoplastic resin containers and paper containers, are
Partial printing on containers, especially on flat parts,
Or it is a simple design, typified by a valve-shaped container for instant cup noodles.

In addition, film J or sheet that shrinks when heated is used as a packaging material for containers, but when any film or sheet is heated and shrunk, irregular distortion occurs during shrinkage, so the design may not be in the correct position. It can be used without any problems even if it is misaligned.

Furthermore, although containers for microwave ovens have been developed in recent years, there have been no heat-insulating containers that can be held and used directly and have printed markings. In addition, it has insulation properties to solve the problem that containers that have just been cooked in a microwave oven are too hot to hold with bare hands, and the food stored in the container can be clearly indicated.
Alternatively, containers with various types of value-added printing have been desired.

On the other hand, even in paper containers, if the temperature of the contents exceeds 80°C, the temperature of the outer wall of the paper container becomes too high and there is a problem that the container cannot be held directly by hand.

In order to solve this problem, insulation is achieved by pasting a label made by cutting a heat-insulating sheet such as expanded polystyrene 1 into the shape of the side of the container (in the case of paper cups, fan-shaped) and pasting it on the outside of the container. Containers were made. Furthermore, a method has been proposed in which a container is manufactured using a laminated sheet in which the above-mentioned sheet and paper are laminated together in advance.

However, in this method, a large amount of cutting waste is generated because the sides of the container are cut into an expanded shape, and the yield of the raw material sheet or laminated sheet made of paper and sheets is significantly reduced. In the process of pasting paper containers and labels, or paper and sheets together, the flatness of the sheets is poor, causing warping,
Due to curling, etc., there may be poor adhesion on some of the bonded surfaces.
Defects such as wrinkles are likely to occur.

[Problem that the invention seeks to solve]

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

[Means for solving problems]

As a means to solve the above problems, the present inventors have developed a method of wrapping a heat-shrinkable expanded polystyrene sheet around a container of a specific shape, thereby achieving the desired heat insulation properties and displaying the label on the container. They have discovered that it can be attached to a predetermined position, and have completed the present invention.

That is, the present invention involves the process of forming a sleeve-shaped label made of expanded polystyrene that is uniaxially heat-shrinkable and has a thickness of about 0.1 to 1.0 times and a foaming ratio of about 2 to 10 times, and a flange at the opening. The outer circumference of the portion of the container in contact with the flange is approximately 0.1 to 30% smaller than the maximum outer circumference of the side wall of the container, and the distance from the maximum outer circumference to the flange is at least 1% of the height of the container. This is a method for manufacturing a container with a label, which comprises the steps of inserting a hollow cylindrical portion of the label formed into a sleeve into the container formed as described above, and heating and shrinking the label wrapped around the container.

[For production]

According to the above manufacturing method, a heat-shrinkable label having heat insulating properties can be reliably wrapped around a predetermined position of a container, so a labeled container with high commercial value can be provided at a low cost.

〔Example〕

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

Figures 1 to 3 show the manufacturing process at each stage in the method for manufacturing a container with a label according to the present invention, and Figure 1 shows a state in which the label is formed into a sleeve shape. FIG. 2 is an explanatory diagram showing a state in which a container is inserted into the label formed into a sleeve shape, and FIG. FIG. 4 is a graph showing the relationship between temperature and standing time for a container with a label and a container without a label manufactured by the method of the present invention.

In FIGS. 1 to 3, 1 is an expanded polystyrene label, 1a is an overlapping part, 2 is a container, 2a is a flange of the container 2, and 2b is an opening.

The expanded polystyrene-based label 1 in the present invention is a foamed polystyrene-based sheet alone, a polystyrene-based resin, or a polystyrene-based resin and high-density polyethylene, low-density polyethylene, polypropylene, ethylene-
This is a sheet in which a film made from an olefin-based mixed resin such as vinyl acetate copolymer is composited with the above-mentioned expanded polystyrene sheet 1, and this is printed.

Expanded polystyrene sheets are produced by thermally decomposing a copolymer resin of styrene and one of general-purpose polystyrene, butadiene, acrylonitrile, methacrylic acid, acrylic acid, maleic anhydride, etc., and a blowing agent, such as carbon dioxide gas or nitrogen gas. Add 0.05 to 3.0% by weight of a chemical blowing agent to the resin, or add 100 g of a low-boiling organic solvent such as a hydrocarbon compound such as butane or pentane or a hydrofluoric compound such as Freon IL 12.114.123.134 to the resin. 0.001 against
~0.07 mol It is injected from the middle of the extruder, mixed to make it tungsten, and manufactured by extrusion.

During extrusion, it is preferable to stretch substantially parallel to the extrusion direction. Cut the extruded sheet into a roughly rectangular shape and use it as a label.
Two opposing sides of the label are glued together to form a sleeve. At this time, the stretching direction is made to coincide with the circumferential direction of the sleeve.

The thickness of the label 1 is 0.1 to 1.0 lll11, and the foaming ratio is 2 to 10 times, preferably 0.2 to 10 times, respectively.
0.6 times, 3 to 8 times.

That is, if the thickness of the label 1 is less than 0.1 ms, the heat insulation properties will be insufficient and the label 1 will be bent when inserted into the container 2, while on the other hand, if the thickness of the label 1 is 1.0 mm or more, it will shrink due to heat. In this case, the difference in curvature between the inner and outer surfaces of the label 1 increases, causing wrinkles on the surface of the label.

Furthermore, if the foaming ratio is less than 2 times, the label 1 may break when formed into a sleeve shape, making it impossible to form it into a cylindrical shape, or when inserting the container 2 into the sleeve-formed label L, the label 1 may break. There is a problem if it becomes bent. Furthermore, since the thermal conductivity is high, the heat insulation properties of the container 2 are reduced.

On the other hand, if the expansion ratio is 10 times or more, secondary foaming will be large during heat shrinkage, making it impossible to attach the label l to a predetermined position on the container 2.

The heat shrinkability of label 1 is measured by the shrinkage rate when immersed in oil at 120°C for 1 minute, and is 30% in the circumferential direction of container 2.
~70%, and -15 to 15% in the height direction of the container (- indicates elongation).

Then, the end faces of the flat label are joined by heat sealing or adhesive to form a cylindrical sleeve as shown in FIG.

The container referred to in the present invention refers to thermoplastic resin, thermosetting resin,
There are no restrictions on materials such as paper and metal, but they are selected depending on the purpose of the container. For example, as a tableware container for use in a microwave oven, a container made of thermoplastic resin or paper is preferable.

A thermoplastic resin container is a solid sheet or low-foam sheet obtained by extruding heat-molten resin in an extruder through a mold slit attached to the tip, and then extruding it using a vacuum forming machine, pressure forming machine, vacuum pressure forming machine, etc. The container is a secondary-processed container or a container molded by an injection molding machine, and there are no particular restrictions on the material of the container as long as it is compatible with the above-mentioned molding method. For example, there are polypropylene, polyethylene, polyethylene terephthalate, polycarbonate, polyamide, polystyrene, etc., but preferably heat distortion temperature (JISK-68
71) is a resin whose temperature exceeds 100°C. If this cannot be satisfied by itself, it can be used by laminating it with a resin having a high heat deformation temperature.

Paper containers include those formed from ordinary paper and processed paper coated with resin such as polyethylene.

As shown in FIG. 2, the shape of the container 2 is such that a flange 2a is provided at the opening 2b, and the outer periphery of the container 2 in contact with the flange 2a is approximately 0.1 to 30% smaller than the maximum outer periphery B of the container. The distance C from the maximum outer peripheral portion 2c to the flange 2a is at least 1% of the height D of the container 2.

The shape of the container 2 is a flange 2a provided at an opening 2b.
The outer circumference A of the container 2 in contact with is about 0.1 of the maximum outer circumference B of the container.
If it is less than %, when the sleeve-shaped label 1 is heat-shrinked after being inserted into the container 2, the label 1 may separate from the flange 2a, making it impossible to attach the label 1 to a predetermined position.

On the other hand, if it exceeds 30%, the contact surface of the flange 2a will be uneven when the bell l inserted into the container 2 is heated and shrunk.

Furthermore, if the distance C from the maximum outer circumference 2c to the seventh flange 2a is less than 1% of the height D of the container 2, when the wrap 1 inserted into the container 2 is heated and shrunk, it may be separated from the contact surface of the flange 2a. and the label cannot be attached in place.

Preferably, the outer periphery A of the container 2 in contact with the flange 2a provided at the opening 2b is approximately 0 of the maximum outer periphery B of the container.
．． 2 to 10%, and from the maximum outer circumference 2C to the flange 2
It is recommended that the distance C to a be 5 to 20% of the height D of the container 2.

After inserting the sleeve-shaped sleeve 1 into the container 2, the label 1 is wrapped around a predetermined position on the outer peripheral wall of the container 2 as shown in FIG. It will be done.

Further, it is preferable to apply a hot melt agent, an adhesive, or a pressure-sensitive adhesive to a part of the interface between the container and the label in order to prevent the label and the container from shifting after heat shrinkage.

Example 1 0.02 fluorocarbons per 100 g of general-purpose polystyrene
5 A foamed polystyrene sheet with a thickness of 0.3 M and an expansion ratio of 5.5 times was injected with towel and extruded to form a foamed polystyrene sheet with a thickness of 0.02 am.
A cylindrical sleeve with an inner diameter of 92+nmφ was prepared by heat-sealing a label laminated with an impact-resistant polystyrene film.

FIG. 2 shows a state in which a sleeve-shaped label I is inserted into the container 2.

The outer circumference A of the container 2 in contact with the flange 2a is 90mmφ,
The depth C from the opening 2b to the maximum outer circumferential portion 2c is 15 mm, and an undercut portion is provided in this portion.

Therefore, the maximum outer diameter B of the undercut portion is 91 m.
A polypropylene cup-shaped container (height: 80 m, flange outer diameter: 96 mm, bottom outer diameter: 7011 Iffiφ) is inverted, and the sleeve-shaped label 1 is inserted into it, so that the end surface of the label L is on the flange 2a. In this state, the label 1 was heated and shrunk by placing it in a heating oven at 130 degrees for 5 seconds. The label 1 was shrunk without being displaced from the flange 2a surface of the container 2.

FIG. 3 shows an example of a container 2 with a label 1 wrapped around it.

Next, the present invention will be explained in more detail based on a typical embodiment of the present invention with reference to FIG.

Figure 4 is a graph showing the relationship between temperature and standing time for labeled containers and unlabeled containers, with the vertical axis showing the temperature ("C") and the horizontal axis showing the standing time. (IIlin). 3 in the graph represents the change in temperature when a labeled container is filled with hot water at a predetermined temperature, while 4 in the graph represents the change in temperature when a single container is filled with hot water at a predetermined temperature. In addition, 5 in the graph represents the change in temperature of the outer wall surface when a labeled container is filled with hot water at a predetermined temperature, while 6 in the graph represents a change in the temperature of the outer wall surface when a labeled container is filled with hot water at a predetermined temperature. It shows the change in temperature of the outer wall surface when filled with

250a of 90°C hot water in each container! Looking at the relationship between the temperature of the filled water and the temperature of the outer wall of the container after filling, as shown in Figure 4, the outer wall temperature of the labeled container is lower than that of the container alone, and the temperature of the filled water can be maintained at a high temperature. It had excellent insulation properties.

Comparative Example 1 The label was made into a sleeve in the same manner as in Example 1, except that 0.3% by weight of baking soda/citric acid was used instead of CFC to create a foam sheet with a foaming ratio of 1.9 times and a thickness of 0.3%. However, it broke at the heat-sealed end face and did not form a cylindrical shape, and when the sleeve-shaped label was inserted into a container, it broke and a crack occurred in the circumferential direction, and when heated, the cracked part A large fissure appeared in the eye.

Comparative Example 2 The amount of Freon injected was 0.06 II per 100 g of resin.
A label was formed into a sleeve shape in the same manner as in Example 1, except that a foam sheet with a foaming ratio of 11 times and a thickness of 0.95M was used, and the sleeve-shaped label was inserted into a container. When the label was heated, it expanded significantly before shrinking and moved out of position, and the label could not be wrapped in the desired position.

Comparative Example 3 Increasing the sheet take-up speed in Example 1
A label was formed into a sleeve under the same conditions except that it was set to Ill, but when trying to put this sleeve into a container, it was bent and the label could not be attached at a predetermined position.

Comparative Example 4 A label was formed into a sleeve under the same conditions as in Example 1 except that the sheet take-up speed was lowered and the thickness was 1.1 m + n. However, the sleeve had creases, and these creases could not be removed even by heat shrinking. There wasn't.

Comparative Example 5 A label was heat-shrinked in the same manner as in Example 1 except that a polypropylene container was used in which the outer periphery of the outer wall surrounding the flange of the container was the same size as the maximum outer periphery of the container body. The label became wrapped around the container away from the flange contact surface and moved out of place.

Comparative Example 6 A label was heat-shrinked in the same manner as in Example 1, except that a container was used in which the outer circumference of the outer wall relative to the flange of the container was 35% smaller than the maximum outer circumference of the container body. The label was partially separated from the contact surface of the flange, and the design was distorted.

Comparative Example 7 A label was heat-shrinked in the same manner as in Example 1, except that a container was used in which the distance above the flange from the maximum outer circumference of the container was 0.5% of the height of the container. The label wrapped around the container away from the flange contact surface and became displaced from its designated position.

〔Effect of the invention〕

Since the present invention is configured as described above, according to the present invention, a heat-shrinkable label having heat insulating properties can be wrapped around a predetermined position of a container. In addition, this labeled container is not only aesthetically pleasing but also has excellent heat insulation properties, and is suitable as a container for microwave ovens.

It should be noted that the present invention is not limited to the embodiments described above, and can be freely modified within the scope of the purpose, and the present invention can be modified to any extent that a person skilled in the art can conceive from the embodiments described above. It is intended to encompass modified embodiments.

[Brief explanation of the drawing]

Figures 1 to 3 show the manufacturing process at each stage in the method for manufacturing a container with a label according to the present invention, and Figure 1 shows a state in which the label is formed into a sleeve shape. FIG. 2 is an explanatory diagram showing a state in which a container is inserted into the label formed into a sleeve shape, and FIG. FIG. 4 is a graph showing the relationship between temperature and standing time for a container with a label and a container without a label manufactured by the method of the present invention. 1-----1----------・--11--Label 1
a ---------・-----1 Overlapping part 2~・
−1−−−−−−−−・−−−m−Container 2a−−−
−−・−=−・−・−Flange part 2b−・−11−−
---------------Opening Figure 4 Temperature (°C) Standing time (min)

Claims (4)

[Claims] (1) A method for manufacturing a labeled container comprising the steps described in items (a) to (c) below. (a) A step of forming a sleeve-shaped label made of expanded polystyrene and having a thickness of about 0.1 to 1.0 mm and a foaming ratio of about 2 to 10 times, which is heat-shrinkable in the uniaxial direction. (b) The outer circumference of the part of the container in which the opening is provided with a flange, which is in contact with the flange, is about 0% smaller than the maximum outer circumference of the side wall of the container.
．． A step of inserting the hollow cylindrical portion of the label formed into a sleeve shape into a container that is 1 to 30% smaller and formed such that the distance from the maximum outer circumference to the flange portion is at least 1% of the height of the container. (c) A step of heating and shrinking the label wrapped around the container. (2) The foaming ratio of the expanded polystyrene label above is 3.
8. The method for producing a labeled container according to claim 1, wherein: (3) The thickness of the above expanded polystyrene label is 0.2
3. The method for producing a labeled container according to claim 1 or 2, wherein the diameter is 0.6 mm. (4) The outer circumference of the portion of the container in contact with the flange is approximately 0.2 to 10% smaller than the maximum outer circumference of the container, and the distance from the maximum outer circumference to the flange is approximately 5 to 5 times the height of the container.
A method for producing a labeled container according to any one of claims 1, 2 or 3, wherein the content is 20%.