JPH1148332A - Curling device for opening of vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To eliminate off-groove as well as the foaming of a side wall unit, improve the degree of cursing and prevent the generation of wrinkles in the part of curling by a method wherein backup rolls are heated. SOLUTION: Backup rolls 2A-2G are arranged rotatably so as to surround the outer periphery of a vessel 10 to transfer the vessels 10,... of laminated condition while pushing respective opening units 11 against a grooved heating roll 1. In this case, only the backup rolls 2A, 2B, 2C, which are contacted with the fore side vessel 10 contacted with the grooved heating roll 1, can be heated. A heating temperature is the degree of 160-250 deg.C while the heating is effected by a method wherein a heater, conducting heat medium, is cast into the backup rolls 2 and the like. Only the part of a vessel, which requires preheating for curling before entering the heating roll, can be preheated in such a manner and the preheating of the vessel in a heating furnace can be eliminated or the heating can be mitigated whereby foaming in the side wall unit of the vessel is restrained and curling capacity can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a curling device for a mouth of a container, and more particularly to a device for curling a foamed sheet molded container or the like using a grooved heating roll. The present invention relates to a mouth curling apparatus for heating a plurality of backup rolls, particularly a backup roll installed before a container comes into contact with a grooved heating roll.

[0002]

2. Description of the Related Art Containers formed from sheets are used in large quantities because they are suitable for mass production and can be obtained at low cost.
However, after forming and forming into a container with a mold, in order to take out the container from the sheet, it is cut and punched with a punch blade, so the cut surface, that is, the outermost corner of the mouth of the container is sharp and square, and soft skin such as lips touches. There are problems such as being hurt. Curling of the mouth is performed to solve these problems.

[0003] Conventionally, in the curling process of the mouth of a container formed from a sheet, a container preheated by a heating furnace such as Brown Co., Ltd. is converted into a curling device including one grooved heating roll and a plurality of unheated backup rolls. (Hereinafter referred to as a first method) and a method of curling while heating the container mouth with three long grooved heating rolls represented by Illich (hereinafter referred to as a second method). Is adopted.)

However, when the first method is adopted, the operation is easy. However, in the case of a foamed sheet molded container, the side wall of the container, which is heated when preheated in a heating furnace, is foamed by heating to provide sufficient preheating. Insufficient preheating on the side folded by curling that does not face the furnace heater due to the thermal insulation effect of foaming due to foaming, the container comes off from the grooved heating roll when curling, and wrinkles frequently occur on the curling part Curling is not good. This phenomenon is more remarkable in a container in which a film is laminated to perform curved surface printing on the outer surface of a foamed sheet molded container. On the other hand, the second
This method has better curling bend than the first method. However, it is difficult to adjust the curling without rotating the three rolls and disengaging from the grooved heating roll. Poor operability such as seriousness is raised.

Further, in the case of a foamed sheet molded container, if the heating required for curling is to be provided only by a heated roll with grooves, a large heating area is required, and the heated roll with grooves becomes longer, or three grooves are required. It is necessary to install a heater in the gap between the heating rolls, which causes problems such as foaming on the side of the container. In addition, there are disadvantages such as an increase in equipment costs because three long grooved heating rolls are required.

[0006]

In view of these circumstances,
Having the operability of the first method and the curling bendability of the second method, there is no foaming on the side of the container even in a foam sheet molded container, and a method capable of sufficient curling has been searched, and the present invention has been reached. did.

[0007]

SUMMARY OF THE INVENTION The present invention relates to a method for curling a mouth, which is a cut surface of a molded container, from a foamed sheet, and a grooved heating roll installed around the mouth of the container to be curled. And a container curling device comprising a plurality of backup rolls, and heating the backup roll, particularly by heating the backup roll installed on the front side where the container comes into contact with the heating roll, before entering the heating roll. It is possible to apply preheating only to a part necessary for curling of the container, so that preheating of the container in the heating furnace can be eliminated or heating can be reduced as compared with the apparatus used in the first method. While suppressing the foaming of the side wall part, the curling ability with the grooved heating roll can be increased, and the curling property can be further improved. A. On the other hand, compared to the apparatus used in the second method, it is possible to use only one grooved heating roll, and it is not necessary to use three or more grooved heating rolls, and the operability is improved. The lengthening of the grooved heating roll and the installation of a heater between the grooved heating rolls are not required.

Further, in either of the first method and the second method, in a container formed from a foamed sheet, a punched cut surface serving as a mouth portion is foamed in a heating furnace during curling. Phenomena such as opening and cracking occur, and the finished state may be significantly impaired, but by heating the backup roll, sufficient heat can be applied to the container mouth part in contact with the backup roll, The cut surface can be melt-fused, and the above-mentioned problem can be prevented from occurring.

[0009]

Next, embodiments of the present invention will be described in more detail with reference to the accompanying drawings. One example of a curling device in the present invention is shown in FIGS. The curling apparatus according to the present invention basically includes a grooved heating roll 1 driven and rotated by a motor (not shown), and an opening 11 of each of the stacked containers 10,. And a plurality of backup rolls 2, rotatably disposed so as to surround the outer periphery of the container 10 for transport.

The grooved heating roll 1 passes a heating oil through a rotary joint 3 into the roll.
Temperature control up to 0 ° C is possible. Grooved heating roll 1
The surface of the container 10 is provided with a continuous spiral groove 4 from the introduction side to the discharge side of the container 10. The mouth 11 to be curled of the container 10 is bitten into the spiral groove 4 to rotate the heating roll. The structure is such that the container 10 can be transported from the introduction side to the discharge side of the heating roll. In FIG. 1, the direction of transport of the container 10 is indicated by an arrow P. The groove shape of the spiral groove 4 is set at the mouth 1 of the container 10 to be curled.
The portion from which the mouth portion 11 to be curled is heated, the portion where compression and curling is performed, the end portion on the discharge side where the curling shape is defined and finished is continuously or stepwise as required, from the leading end portion on which the bite 1 is introduced. Curling can be performed by changing the groove width and depth and compressing the shape of the mouth, especially changing the groove shape at the compression / curling part, and the part that determines the shape does not generally change the shape .

The backup roll 2 has a function of holding the container 10 to be curled and a function of transporting the container 10. A plurality of, preferably five or more, backup rolls 2 are provided in contact with the outer periphery of the container 10 to be curled. In the form, seven are installed at equal intervals. The backup roll 2 may have a smooth surface and does not need to be particularly grooved. Each of the backup rolls 2,... Needs to rotate in accordance with the rotation of the grooved heating roll 1. The backup rolls 2 to be heated may be all backup rolls 2,..., But may be about 1 to 3 rolls that contact the front container 10 that contacts the grooved heating roll 1. In this embodiment, three backup rolls 2,... Indicated by reference numerals 2A, 2B, 2C in FIG.
The other backup rolls 2 shown as 2G are not heated. The temperature for heating the backup roll 2 is preferably about 160 to 250 ° C. As a heating method, there is a method of flowing a heat medium into the inside of the backup roll 2, casting a heater, and the like, but a portion to be heated preferentially a portion to be heated of the grooved heating roll 1 and a portion corresponding to a portion to be compressed and curled. It is better to suppress the heating at the portion where the heating is performed and the curling shape is determined. Therefore, it is preferable to cast the heater which can partially heat.

In FIG. 1 and FIG. 2, what is indicated by reference numeral 5 is a preheating furnace for the container, which has a structure in which the periphery of the container 10 is heated by an infrared heater or the like. Usually, sufficient heat can be supplied by heating the backup roll 2 so that it is not particularly necessary. However, it is effective when used for curling a heavy container or for high-speed processing.

In curling, the mouth portion 11 of the container 10 is generally formed into a U-shape as shown in FIGS. 4 and 5A, and the U-shape portion is generally folded and curled. FIG. 5B shows a cross-sectional shape after the mouth portion 11 has been subjected to a curling process by a curling device.
In addition, sheets used for container molding include non-foamed sheets of thermoplastic resins such as polystyrene, polypropylene, polyethylene terephthalate, and polycarbonate, and foamed sheets made of polystyrene and the like, and sheets obtained by laminating various films on one or both sides of a foamed sheet. However, the effects of the present invention can be more remarkably exhibited in a foamed sheet and a foamed sheet molded container obtained by laminating a film on the foamed sheet.

[0014]

The present invention will be described below with reference to specific examples.

A laminated foamed polystyrene sheet in which a high-impact polystyrene film having a thickness of 180 μm is bonded to a foamed polystyrene sheet having a basis weight of 350 g / m ^{2 on} the outer surface side of the container is used. A container having an outer diameter of 100 mmφ and a height of 80 mm shown in FIG. 4 is used. No. 10 was molded. As shown in FIGS. 4 and 5A, the shape of the mouth portion 11 of the container 10 cut out of the sheet has a horizontal portion 13 extending outward at the opening edge of the container body 12 and a lower portion extending from the horizontal portion 13. A skirt portion 14 extends slightly obliquely outward, and a flange portion 15 slightly protrudes outward from the lower end of the skirt portion 14.

The above-mentioned container 10 was curled using a grooved heating roll 1 in which 50 continuous spiral grooves 4 having a length of 500 mm and a diameter of 120 mmφ were dug. The groove shape of the grooved heating roll 1 is 4.5 m in width at the leading end on the introduction side.
m, a rectangle of 3.5 mm in depth, a width of 3.5 mm and a depth of 3.0 mm from the tip to 30 mm, gradually filling the mouth 11, and a groove width of 30 to 40 Curling is performed as a compression / curling portion by reducing the depth to 2.0 mm and the depth to 2.5 mm, and thereafter, the shape is determined as a shape determining portion having the same groove shape up to the end on the discharge side.

The backup roll 2 has a length of 500 m.
m, having a smooth surface with a diameter of 30 mmφ, and using seven rolls rotating at the same peripheral speed in accordance with the rotation of the heating rolls, of which the reference numeral 2 in FIG.
Three pieces designated as A, 2B and 2C were heated using a casting heater.

As shown in FIG. 5B, the shape of the mouth portion 11 after the curling process is such that the skirt portion 14 is
3 and has a shape in contact with or close to the outer surface of the container body 12.

Table 1 below also shows the results of tests conducted without heating the backup roll at all as Examples 1 to 4 and Comparative Example. Note that none of the preheating furnaces 5 was used.

[0020]

[Table 1]

[0021]

As described above, the curling device at the mouth of the present invention, by heating the backup roll, does not lose the groove at the time of curling, does not foam on the side wall of the container, has a good degree of curling bending, and has wrinkles at the curling portion. In addition, it is possible to obtain a container having no crack by fusing the cut surface of the container.

[Brief description of the drawings]

FIG. 1 is a simplified side view of a mouth curling device for a container according to the present invention.

FIG. 2 is a simplified front view of the same container viewed from the transport direction.

FIG. 3 is a partially enlarged side view illustrating a relationship between a grooved heating roll and a mouth portion of a laminated container.

FIG. 4 is a half sectional view of a container to be subjected to a curling process by the mouth curling apparatus of the present invention.

FIGS. 5A and 5B are enlarged cross-sectional views of a mouth portion of the container, wherein FIG. 5A shows a state before the curling process, and FIG. 5B shows a state after the curling process.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Heating roll with a groove 2, 2A-2G Backup roll 3 Rotary joint 4 Spiral groove 5 Preheating furnace 10 Container 11 Mouth part 12 Container main body 13 Horizontal part 14 Skirt part 15 Flange part

Claims (4)

[Claims] 1. A mouth curling device for a container having a grooved heating roll and a plurality of backup rolls installed around the mouth of the container to be curled, wherein the backup roll is heated. 2. The mouth curling apparatus for a container according to claim 1, wherein the number of the grooved heating rolls is one. 3. The container curling device according to claim 1, wherein the backup roll to be heated is a backup roll installed before the container rotates and comes into contact with the grooved heating roll. 4. The curling device according to claim 1, wherein the container to be curled is a foamed sheet molded container.