JPH0994875A - Container made of laminated styrene resin foamed sheet and its preparation - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a safe container which solves various problems caused by projection of a rigid resin film layer to the outside on the cut face (the mouth of the container) of the container made of a laminated styrene resin foamed sheet and prevents ruptures of lips and fingers from occur caused by bringing them into contact with the rigid and sharp resin film. SOLUTION: A container 10 is prepd. by molding a container main body 11 by heat-molding of a laminated styrene resin foamed sheet prepd. by laminating a styrene resin foamed sheet 14 with a thermoplastic resin film 15 at least on its one face so as to make the resin film to be the outer surface and cutting it in such a way that a mouth 13 extended outside is left on the surrounding of the opening 12 of the container main body 11. In addition, the edge of the cut face 16 is made round by shrinking the resin film of the mouth 13 by heating.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a laminated styrenic resin foam sheet container used for food packaging or tableware when eating, and a method for producing the same, and more particularly to a styrene resin foam sheet and at least one surface thereof. The present invention relates to a container in which a laminated styrene-based resin foam sheet obtained by laminating a thermoplastic resin film on a thermoplastic resin film is heat-molded so that the resin film is on the outer surface, and cut and separated at the mouth, and a manufacturing method thereof.

[0002]

2. Description of the Related Art A container produced by heat-molding a laminated styrene resin foam sheet obtained by laminating a non-foamed thermoplastic resin film on a styrene resin foam sheet has excellent heat insulation and lightweight properties and is inexpensive. In addition to the characteristics of the styrene-based resin foam sheet container such as that, by laminating a thermoplastic resin film, the container strength is improved,
It has a smooth surface and can be used for curved surface printing.

The laminated styrene resin foam sheet container is
After heating the laminated styrene resin foam sheet and sending it between the male and female molds of the molding machine to heat-mold the container body, a trimming blade is used to leave the mouth protruding outward around the opening of the container body. It is punched out and made into individual containers. That is, in such a container, the punching cut surface is the end surface of the mouth.

However, when punching with a trimming blade, due to the difference in hardness between the styrene resin foam sheet layer and the laminated thermoplastic resin film layer, the cut surface (the container mouth) is hard and the styrene resin foam sheet is soft. It becomes a state of protruding outside the layer and the shape of the cut surface of the resin film becomes sharp. Therefore, not only is the mouth feel uncomfortable when touching the mouth of the container, but there is a possibility that the hard film layer may tear the lip when the lip is intentionally rubbed strongly against the mouth. In addition, the possibility of hurting fingers when handling a container cannot be denied.

[0005]

SUMMARY OF THE INVENTION In view of such circumstances, the present invention solves the above-mentioned problems due to the hard resin film layer protruding outside at the cut surface (container mouth) of the laminated styrene resin foam sheet container. The present invention provides a safe container in which cracks on lips and fingers due to contact with a hard and sharp resin film are prevented, and a method for producing the same.

[0006]

In order to solve the above-mentioned problems, the present invention provides a laminated styrene resin foam sheet obtained by laminating a styrene resin foam sheet and a thermoplastic resin film on at least one surface of the styrene resin foam sheet. A container formed by heat-molding the surface of the container body to form a container, and then cutting the resin film at the mouth by heating the container body while leaving the mouth protruding outward around the opening of the container body. A laminated styrene resin foam sheet container characterized in that the edges of the cut surface are rounded by shrinking with. That is, the thermoplastic resin film located on the lower surface of the mouth protruding outward around the opening of the container body is contracted by heat, and the end surface of the resin film is pulled inward, that is, retracted toward the opening. By doing so, the edge of the mouth cut surface is rounded. Here, the reason why the thermoplastic resin film is shrunk by heating is that the laminated styrenic resin foam sheet is originally stretched during heat molding.

After the laminated styrene resin foam sheet obtained by laminating the styrene resin foam sheet and the thermoplastic resin film on at least one surface of the laminated styrene resin foam is heat-molded so that the resin film is on the outer surface to mold the container body. , After forming a container by leaving a mouth protruding outwardly around the opening of the container body to form a container, the thermoplastic resin film surface of the mouth is contracted by contact with a heating plate or exposure to a heat ray to shrink Provided is a method for producing a laminated styrene-based resin foam sheet container, characterized in that the edge of the surface is made to recede in a direction along the thermoplastic resin film. Here, the edge of the cut surface of the mouth is contracted and retracted in the direction along the thermoplastic resin film by exposing the thermoplastic resin film surface located on the lower surface of the mouth to a heating plate or exposing it to heat rays. Rounds.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION The styrene resin foamed sheet of the present invention means a styrene homopolymer resin, a copolymer resin with a monomer such as butazine, methacrylic acid and maleic anhydride, which is copolymerizable with styrene, and a mixed resin of these resins. , And even
A foamed sheet is obtained by kneading a styrene resin such as a mixed resin of these resins and a resin such as polyphenylene oxide that can be mixed with a foaming agent such as butane or freon in an extruder, and then extruding and foaming. A sheet thickness of 1 to 3 mm and a sheet basis weight of 150 to 550 g / m ² are generally used, but are not limited to this range.

The thermoplastic resin film laminated and laminated on a styrene resin foam sheet is a styrene resin film selected from the resins used for the styrene resin foam sheet, or a polyethylene, polypropylene or the like. Examples thereof include olefin resin films, polyester resin films such as polyethylene terephthalate, and various films such as polyvinyl alcohol and gas barrier films such as vinylidene chloride, which may be used alone or in combination. These thermoplastic resin films can be laminated on one side or both sides of a styrene resin foam sheet. When laminating on both sides, the same kind of film or different kinds of films may be stuck on both sides. Further, in a container in which a thermoplastic resin film is laminated on both sides of a styrene resin foam sheet, the film to be laminated on the outer surface side of the container is not particularly limited because it is determined from the desired container quality, It is preferable that the thicker film is laminated on the outer surface side.

As a method of laminating and compounding a thermoplastic resin film on a styrene resin foam sheet, a method of dropping a film resin on a styrene resin foam sheet to laminate it, a method of directly laminating a resin film by heat, and There is a method of laminating resin films via an adhesive.

A method of manufacturing the container 10 from the laminated styrenic resin foam sheet obtained by the above method will be briefly described with reference to FIG. First, the laminated styrene resin foam sheet 1 wound in a roll is heated through a heating furnace 2 and heated.
After the subsequent foaming, the container body 11 is molded by the male and female mold 3. At the time of this molding, the inside of the male and female mold 3 is evacuated to a vacuum exhaust means
The pressure is reduced with to improve the mold shape transferability. After molding the container body 11, the mouth 13 protruding outward from the opening 12 of the container body 11 is cut from the laminated styrene resin foam sheet 1 with an automatic punching machine 5 equipped with a punching blade or a Thomson blade. Punch and leave individual containers 10
And An example of the container 10 thus obtained is shown in FIG.
Is shown in FIG. 3 is an enlarged view of the mouth 13 of the container 10. In FIG. 3, 14 is a styrene resin foamed sheet, 15 is a non-foamed thermoplastic resin film, and when the thermoplastic resin film 15 is laminated on one side, this thermoplastic resin film 15 becomes the outer surface. The container 10 is molded into. Further, when the thermoplastic resin films 15 are laminated on both surfaces of the styrene resin foam sheet 14, one of the thermoplastic resin films 15 is used for the container 1
Of course, it is located on the outer surface side of 0. In the present invention, attention is paid to the thermoplastic resin film 15 located on the outer surface side of the container 10.

Here, when the container 10 is cut and separated from the laminated styrenic resin foam sheet 1 by the automatic punching machine 5, the hard thermoplastic resin film 15 is punched and the resistance when cutting is strong, and the cut surface 16 is An end portion of the thermoplastic resin film 15 located on the outer surface side of the container 10 has a shape protruding outward from an end surface of the styrene resin foam sheet 14.

Since the laminated thermoplastic resin film 15 is stretched by the stretching operation during molding, it is easily contracted when heat is applied. Therefore, mouth 1 that you want to shrink with heat
It is necessary to apply heat only to the lower surface part of 3. Therefore, the thermoplastic resin film 1 of the mouth 13 desired to be contracted
5, that is, it is preferable to use a heating plate or a heating plate capable of applying heat only to the thermoplastic resin film 15 corresponding to the outer surface side of the container 10.

FIG. 4 shows a processing method using a hot platen, namely,
An annular heating plate 8 is arranged on the upper end of the hollow container support 6 via a heat insulating material 7, and the container body 11 is inserted so as not to come into contact with the inside of the heating plate 8 and the upper surface of the heating plate 8 is inserted. To mouth 13
Of the thermoplastic resin film 15 by heating by contacting the lower surface of the
The end portion of the film 15 is retracted inward by heat-shrinking so that the cut surface 16 is rounded as shown in FIG. In this way, in the container 10 in which only the thermoplastic resin film 15 at the mouth 13 is shrunk by heat, the end portion of the resin film 15 is pulled inward as shown in FIG. Since the end face also curls a little so that it is pulled in, when the lip is put on the mouth 13, it does not directly hit the hard thermoplastic resin film 15 but hits the soft styrene resin foam sheet 14,
The texture becomes softer.

Further, in FIG. 6, the shape of the hot platen 8 is such that an inclined portion 9 is formed at a portion of the mouth 13 where the end portion of the thermoplastic resin film 15 comes into contact, and the inclined portion 9 is directly in front of the inclined portion 9. By contacting the edge of the film 15, the contact time between the edge of the lower surface of the mouth 13 and the heating plate 8 becomes longer than that of the other lower surface portions, so that heating is performed preferentially and thermal deformation occurs in that portion. In addition to the heat shrinking action of the film 15 of
An example is shown in which the sharp edges of the cut surface 16 are forcibly formed so as to be smooth.

Although not shown, it is possible to heat only the thermoplastic resin film 15 on the lower surface of the mouth 13 by exposing it to the heat rays from the infrared heater. In this case, it is possible to protect the container body 11 or the like from the heat ray so that the heat ray of the infrared heater does not heat the container body 11 or other non-heated portions, or to cut off the heat ray for controlling the heating time. It is necessary to devise such as providing a different shutter or intermittently energizing the infrared heater.

Here, the temperature of the hot platen and the hot wire varies depending on the film material to be shrunk and the thickness, but in general, 130 ° C. to 250 ° C. is preferable. The time to contact the hot platen is 1 second in a short time.
It is better to press the mouth 13 of the container 10 against the hot platen 8 with a weak force of about f.

The thermoplastic resin film 15 at the mouth 13
The step of shrinking may be performed at any time after manufacturing the container.

[0019]

[Examples] Specific examples will be described below in more detail. A laminated styrene resin in which a container having an outer diameter of 140 mmφ and a height of 73 mmH shown in FIG. 2 is laminated with a film of a high impact styrene resin having a thickness of 150 μm on a styrene resin foam sheet having a thickness of 250 g / m ² and a thickness of 2.3 mm. A foamed sheet was used and molded so that a film was exposed on the outer surface of the container. After molding, punching the container with a punching blade, and looking at the cross-sectional shape of the mouth of the container, as shown in FIG. 3, the end of the film 15 projects outside the mouth 13, and it hurts when the cut surface 16 is rubbed by hand. There was a risk of hurt.

This container was placed on a circular table with a heating plate at 160 ° C. as shown in FIG. 4, and a flat plate was pressed from above with an air pressure of 1.5 kgf for 1.0 second. The shape of the mouth of the container obtained as a result of shrinking the film part is as shown in FIG. 5, the film part was pulled inward, and the film end part was rounded. The styrenic resin foam sheet had a shape protruding to the outside, but it was soft and did not feel pain even when the mouth section was rubbed with a hand, and there was no fear that the hand would be scratched.
Further, it was not scratched even if it was rubbed against the lips, and the mouthfeel was good.

[0021]

According to the container made of a laminated styrene resin foam sheet and the method for producing the same of the present invention having the above contents,
By shrinking the edge of the hard thermoplastic resin film located at the mouth with heat and pulling it inward from the cut surface, it is possible not only to prevent the lip from touching the hard film and tearing, but also soft styrene resin foam Since the sheet will be touched, the mouth feel will be very good. Further, since the film portion is contracted by heat, the sharpness of the cut surface of the film is eliminated, which is preferable. Furthermore, after cutting the molded part of the container from the laminated styrenic resin foam sheet, the film is shrunk by heat, so that it can be easily incorporated into the post process such as container manufacturing and printing, which is advantageous in terms of process and cost. is there.

[Brief description of drawings]

FIG. 1 is a simplified layout view showing a part of a container manufacturing apparatus according to the present invention.

FIG. 2 is a side view showing the container in a partial cross section.

FIG. 3 is an enlarged cross-sectional view of a mouth portion after punching a container from a laminated styrene resin foam sheet.

FIG. 4 is a simplified cross-sectional view of an apparatus for heating a mouth cutting portion with a heating plate.

FIG. 5 is an enlarged sectional view of a mouth portion of the container of the present invention.

FIG. 6 is a partial cross-sectional view showing another processing example using a hot platen.

[Explanation of symbols]

 1 Laminated Styrene Resin Foamed Sheet 2 Heating Furnace 3 Mold 4 Vacuum Evacuation Means 5 Automatic Punching Machine 6 Container Cradle 7 Heat Insulating Material 8 Hot Plate 9 Inclined Part 10 Container 11 Container Body 12 Opening 13 Mouth 14 Styrene Resin Foamed Sheet 15 thermoplastic resin film 16 cut surface

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI Technical display area B65D 1/09 B65D 1/00 B // B29K 25:00 105: 04 B29L 9:00 31:00

Claims (4)

[Claims] 1. A container body is formed by thermoforming a laminated styrene resin foam sheet having a styrene resin foam sheet and a thermoplastic resin film laminated on at least one surface thereof so that the resin film is on the outer surface. A container formed by cutting while leaving an outwardly projecting mouth around the opening of the container body, characterized in that the resin film at the mouth is contracted by heat so that the edge of the cut surface is rounded. A laminated styrene resin foam sheet container. 2. The container made of a laminated styrene resin foam sheet according to claim 1, wherein the thermoplastic resin film located on the lower surface of the mouth of the container is heat-shrinked. 3. A laminated styrene resin foam sheet obtained by laminating a styrene resin foam sheet and a thermoplastic resin film on at least one surface of the laminated styrene resin foam sheet after thermoforming so that the resin film is on the outer surface of the container body. , After forming a container by leaving a mouth protruding outwardly around the opening of the container body to form a container, the thermoplastic resin film surface of the mouth is contracted by contact with a heating plate or exposure to a heat ray to shrink A method for producing a laminated styrene resin foam sheet container, characterized in that the edge of the surface is set back in the direction along the thermoplastic resin film. 4. The method for producing a laminated styrene resin foam sheet container according to claim 3, wherein the surface of the thermoplastic resin film located on the lower surface of the mouth of the container is contracted by contact with a heating plate or exposure to heat rays.