JPS59199460A - Sealed vessel and manufacture thereof - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION More specifically, the present invention relates to a sealed container with excellent internal pressure resistance, in which an inner layer is bonded to an outer flange of a container body by heat fusion, and a method for manufacturing the same.

Conventionally, as shown in FIG. 1, a peripheral edge 2a of a lid part 2 is heat-sealed to the upper surface of an outer flanged part 1a of a container body made of thermoplastic plastic, for example, to form a heat-sealed part 4. A sealed container 3 manufactured by This type of sealed container 3 can be put to practical use when the content 5 is a type that does not generate positive internal pressure, such as juice or alcoholic beverages, but it can be put to practical use when the content 5 is of a type that does not generate positive internal pressure, such as beer or carbonated drinks, but it is of a type that generates internal pressure after filling and sealing, such as beer or carbonated drinks. In this case, as described below, the heat-sealed part 4 is
This causes a problem in that the sealing properties are likely to be impaired due to peeling.

Figure 1 shows the state immediately after filling the container body 1 with positive internal pressure contents 5 at a low temperature (for example, 5° C.) and immediately sealing it with the lid 2. In this state, the contents 5 are At low temperature,
Since the internal pressure generated is substantially close to atmospheric pressure, the lid 2 and the bottom IC of the container body 1 are not deformed. However, several minutes later, as the temperature of the contents approaches room temperature, the internal pressure rises, and as shown in FIG. Although not shown, 1b also bulges slightly outward in the radial direction.

Then, after 1 to 2 hours have passed, it bends inward and upward using the point shown in Figure 3 as a fulcrum. This is the internal pressure (e.g. 3kp
It is presumed that this is due to the radially inward tension generated in the lid part 2 due to /ctn) and the swelling caused by the internal pressure of the portion of the body part 1b directly below the flange part 1a. Peeling angle β in the heat-sealed part 4 when bent as described above (Fig. 3)
is much larger than the peeling angle α (FIG. 2) in the normal case where there is no bending, so it can be inferred that the peeling of the heat-sealed portion 4 is accelerated as shown in FIG. 4.

It is an object of the present invention to solve the problems of the prior art described above.

To achieve the above object, the present invention provides a sealed container in which a lid part whose inner layer is made of thermoplastic resin is fully joined to an outer flange part of a container body, the outer flange part being attached to the inner circumferential surface of the outer flange part. An annular groove having an opening and having a shape corresponding to the peripheral edge of the lid, and a layer forming at least the lower surface of the lid, which is made of a thermoplastic resin that can be heat-sealed to the thermoplastic resin of the inner layer of the lid. The present invention provides a sealed container characterized in that the inner layer of the peripheral edge of the lid portion and the layer forming the lower surface of the annular groove are heat-sealed.

Further, in the present invention, the layer forming the upper surface has a flange-like outward protrusion made of thermoplastic resin, and the outer diameter is larger than the outer protrusion on the outer protrusion of the main part of the container formed at the open end. A peripheral edge portion of a lid portion having at least an inner layer made of a thermoplastic resin that can be heat-sealed to the thermoplastic resin of the layer forming the upper surface is placed on the outer diameter of the outwardly protruding portion, and on the peripheral edge of the part, the outer diameter and the inner diameter of which are approximately equal to the outer diameter and inner diameter of the outwardly protruding part, respectively, and the layer forming the lower surface thereof is heat-sealable to the thermoplastic resin of the layer forming the upper surface. A ring body made of a thermoplastic resin is placed, and the upper surface of the outwardly protruding portion, the inner layer of the peripheral edge of the lid portion, and the lower surface of the portion of the ring body facing the outwardly protruding portion are thermally fused. The present invention provides a method for manufacturing a sealed container characterized by:

Further, the present invention provides a flange-shaped outward protrusion in which the layer forming the upper surface is made of thermoplastic resin, and the upper surface is formed on the outward protrusion of the main part of the container formed at the open end. a thermoplastic resin that forms an annular body made of a thermoplastic resin that is heat-sealable to the thermoplastic resin of the layer, and whose outer diameter and inner diameter are approximately equal to the outer diameter and inner diameter of the outwardly protruding portion, respectively; The peripheral edge of the lid part having a heat-sealable inner layer is embedded, and at least the inner layer is heat-sealed to the annular body. The present invention provides a method for manufacturing a sealed container characterized by heat-sealing the side protrusion.

The present invention will be described below with reference to the drawings which are examples. 7. The sealed container 13 shown in FIG.
The peripheral edge 12a of the lid 12 is heat-sealed to an annular groove 16 of an outer flange 11a extending radially outward of the container body 11.

Of the Franz part 11a, it consists of a part 11a+ extending radially outward approximately below the peripheral edge part 1.2a of the lid part (hereinafter referred to as the lower Franz part), a cylindrical body part 1, 1b, and a bottom part 11c. The cup-shaped container main portion 11x is made of thermoplastic plastic.

If the content 5 is a positive internal pressure liquid such as beer, but the storage period is about 1 to 2 weeks, the sealed container 1:3 should be filled with particularly large gases (such as carbon dioxide and Since barrier properties (to oxygen, water vapor, etc.) are not required, the container main portion 11x is formed from a general-purpose thermoplastic resin such as polyethylene or polypropylene. However, if it is intended for relatively long-term storage of more than two weeks, materials with gas barrier properties, such as polypropylene layer - acid-modified polypropylene layer - ethylene vinyl alcohol copolymer layer - acid-modified polypropylene layer - polypropylene layer It is desirable to form a laminate of five layers, or polyethylene terephthalate, or the like.

The part of the flange part above the flange lower part 11a1 (
The upper flange part 11a2 (hereinafter referred to as the upper flange part 11a2) is made of a thermoplastic resin that can form a strong heat-sealed part 14 (see FIG. 6) with the thermoplastic resin forming the upper surface of the lower flange part 11a1. That is, for example, if the former is made of polypropylene, the latter is also made of polypropylene. Therefore, the flange upper part 11a2 and the Franz lower part 11
az (r'';,, are integrated via the heat-sealed part 14 to form the outer flantz part 11a. On the inside of the heat-sealed part 14 of the flanz part 11a, there is a peripheral edge part 12a of the lid part.
an annular groove 1 having a shape corresponding to that of the annular groove 1 extending radially outward and having an opening 16a on the inner circumferential surface of the flange portion 11a;
6 is formed, and a peripheral edge 12a of the lid portion is buried inside the annular groove 16 and heat-sealed.

As shown in FIG. 6, the inner layer 12x of the lid part 12 is made of a thermoplastic resin (for example, polypropylene) that can form a strong heat-sealed part 17 with the thermoplastic resin (for example, polypropylene) that forms the upper surface of the lower Franz part 11al. polynolopyrene), and its thickness is, for example, 20 to 500 μm, preferably 50 μm.
~250 μm.

The middle layer 12y of the lid is made of metal foil (for example, thickness 50-250
aluminum foil with a thickness of 70 to 150 μm)
Therefore, the gas barrier property of the lid part 12 is ensured, and as will be described later, it is possible to form a thermally fused part 14.17 by high-frequency induction heating. This is mainly provided to prevent corrosion of the metal foil of the layer 12y and to reinforce the lid.
For example, the outer layer 12z is made of an epoxyphenol-based coating or printed film, or a plastic film of polyethylene terephthalate, polyamide, etc., but the outer layer 12z is firmly heat-fused to the thermoplastic resin (for example, polypropylene) forming the upper Franz part 11a2. When the portion 18 is made of a thermoplastic resin (for example, polynolopyrene having a thickness of 10 to 200 μm), the sealing performance of the sealed container 13 is further improved.

In FIG. 5, reference numeral 20 denotes an outer cylinder, which has an inner diameter substantially equal to the outer diameter of the body 11b to the extent that the 1" lb body of the container body immediately after sealing and before expansion can be inserted. Securing the royal stability of the sealed container 13 with a bulged bottom part and 1.
, has a function of suppressing the radially outward expansion of the relatively thin body portion 11b (for example, 02-05 deaf) in order to save material costs. The sealed container 13 and the outer cylinder 20 constitute a container complex IO.

The outer cylinder 20 is preferably made of a laminate mainly made of paper material, which has a relatively low material cost. That is, the body is preferably heat-sealed to prevent softening of the paper material layer (for example, made of kraft paper) due to liquid temperature and IIK (not shown), and to heat-seal the overlapped side portions after rolling. Delicately water-resistant and heat-sealable materials (e.g. polyethylene)
The upper end surface 20al is also made of a water-resistant layer (not shown, for example, wax). (consisting of) protected by K.

The thickness of the body portion 20a is approximately 0.3 mm to ensure the necessary strength.
~1.0 mm is desirable. In the case of FIG. 5, in order to reinforce the body part 20a, a bottom part 20b made of the same laminate as the body part 20a is joined to the lower end of the body part 20a by heat sealing.

Since the sealed container 13 has a relatively thick flange portion 11a (preferably 3 to 10 wn), the base portion 11a3 of the sealed container 13 is relatively thick.
It is difficult to bend inward and upward using the fulcrum.

Since the heat-sealed portion 17 with the peripheral edge 12a of the upper lid portion is formed not on the upper surface 11a4 of the flannel portion but below it, the moment is smaller than when it is formed on the upper surface 11a4. Therefore, the flange portion 11a is unlikely to bend inwardly and upwardly as shown in FIG. 3 due to internal pressure.

Therefore, there is no possibility that peeling of the heat-sealed portion 17 will be promoted by the above-mentioned marks. Furthermore, even if separation as shown in FIG. 4 were to occur, the Franz upper portion 11a
2, such peeling does not occur. Therefore, abrasion force mainly acts on the heat-fused portion 17 based on the radially inward tension generated within the lid portion 12. The wear part generally has a large resistance to abrasion forces, so
There is no risk that the heat-sealed portion 17 will shift and the sealing performance will be impaired. When the heat-sealed portion 18 is formed, this shift is even less likely to occur.

As mentioned above, in order to reduce the bending moment caused by the lid part]2, it is preferable that the peripheral edge part 12a of the lid part 12 is located below the flange part 11a as much as possible. As a result, the flange lower part 11a1 becomes thin and easily deforms, and therefore, due to the internal pressure, the part corresponding to the heat-sealed part 17 bends downward and outward using the vicinity of the outer end of the lower part 11a+ as a fulcrum, causing the heat-sealing to occur. This is not preferable because the portion 17 is likely to peel off.Franz upper portion 11 a
2 and the lower Franz part 11a, the preferred thickness is:
Although it varies depending on the strength of the material forming these, when the flange portion 11a is made of polyolefin such as polypropylene, it is usually about 1 to 10 m1, preferably about 1.5 m.
~70mm, and 0.5~4.5m, more preferably 1.5~3.0mm, and the total thickness of the flange portion 11a is preferably 3~lOwn.

Furthermore, in the above case, the width (radial length) of the heat-sealed portion 17
In order to prevent shearing due to the shearing force, it is desirable that the shearing force is about 3 degrees or more. Further, the width (radial length) of the heat-sealed portion 14 is preferably about 2 or more in order to prevent the above-mentioned bending and peeling.

Next, an example of a method for manufacturing the container composite IO will be described.

Reference numeral 21 in FIG. 7 shows a heat fusion device, which includes a flantz-shaped outward protrusion 11x+ (lower flange portion 11a in FIG.
1), an air cylinder 23 for moving the support 22 up and down, and a high-frequency induction heating coil device 24 fixed to a frame 25.

The high frequency induction heating coil device 24 includes a heating coil 24a1
, a feeder 24b1 that supplies current to the heating coil 24a.
and a heat-resistant elastic thin film 24C (made of silicone rubber, for example) attached to the lower surface of the heating coil 24a; functions to apply a uniform pressing force along the circumferential direction of the outward protrusion 11 Xi during pressing described later. ) The container main portion 11
lx1 is placed on the support 22. almost at the same time,
On the outer protruding part 11
A ring body 26 (corresponding to the upper flange part 11a2 in FIG. 6) that is approximately equal to the inner diameter and outer diameter of i is attached to the main part of the container llx.
Place it coaxially with the

Immediately thereafter, the air cylinder 23 causes the support 22 to
by raising the outward protruding portion 11XI and the lid peripheral portion 12a.
Then, the ring body 26 is pressed through the elastic thin film 24c so that a predetermined pressure is applied between the support body 22 and the heating coil 24a, as shown in FIG. 8, and the heating coil 24a is energized almost simultaneously.

Due to this energization, the metal foils of the intermediate layer 12a and 2y of the lid peripheral edge 12a are heated by high frequency induction, and the temperature rises.
The thermoplastic resin in the vicinity of the upper surface of the inner layer 12x1 of 2a and the portion of the outwardly protruding portion 11x+ that contacts the inner layer 12x is melted to form a thermally fused portion 17. When the outer layer 12z is also made of thermoplastic resin, the heat-sealed portion 18 is formed in the same manner. Furthermore, by appropriately determining the output and energization time of the heating coil 24, the thermoplastic resin in the vicinity of the upper surface of the outwardly protruding portion 11 In this way, the heat-sealed portion 14 shown in FIG. 6 can be formed.

Thereafter, the heating coil 24a is deenergized, and after the resin in the heat-sealed portion is cooled and solidified, the support body 22 is lowered by the air cylinder 21 to release the suppression. As described above, as shown in FIG. A sealed container 13 having a portion 18) formed therein is manufactured.

Then, immediately, preferably before the temperature of the contents 5 rises, the body 11b of the sealed container 13 is inserted into the outer cylinder 20,
A container composite 10 is manufactured.

When the temperature of the contents 5 reaches room temperature over time, as shown in FIG.
and the bottom 11 cij bulges outward.

Sealed container 33il-il and sealed container 13 shown in FIG.
Since the manufacturing method is different from that of the heat-sealed part 34,
Its structure and effects are almost the same as those of the sealed container 13, except that it is formed below the container 2a and extends outward in the radial direction. The sealed container 33 is manufactured as follows.

It has a cavity 40'a having a shape corresponding to a part of the flange part 31a of the container body 31 above the heat-sealed part 34 (hereinafter referred to as the upper flange part 31a2) and a closing part 35' which is the lid part 12. After placing the lid part 12 on the lower mold 40b of the mold 40 shown in FIG. , flange upper part 31 a2Vc
The lid peripheral part 12a is embedded in the corresponding annular body 46, and the inner layer 12X (not shown in FIG. 11) of the peripheral part 12a and the lower surface of the annular groove 36 are heat-sealed to the heat-sealed part 37 (
A closure body 35 is formed in which a heat-sealed portion 38 is also preferably formed.

Next, the part (
The contents 5 are placed in a container main portion 31x having an outward protrusion 31x1 having a shape corresponding to the flange lower portion 31a+).
After filling the annular body 46 of the closure body 35 with the outward protrusion 3
1 33 is also manufactured.

The present invention is not limited by the above embodiments,
For example, the lower part of Furanzo may be made of a laminate with a relatively thin lower layer of metal and an upper layer of thermoplastic resin (the upper and lower layers are bonded together with a suitable adhesive). Alternatively, the ring body 26 may be formed of a laminate in which the lower layer is made of thermoplastic resin and the upper layer is made of metal or thermosetting resin. Furthermore, the lid portion 12 may be formed of a single thermoplastic resin that does not contain metal foil, or a laminate in which the intermediate layer 12y is made of a gas barrier resin. Thermal fusion for manufacturing the sealed container 13 in this case is performed by an ultrasonic method, a hot plate method, or the like.

Further, the bottom of the main portion of the container may be formed in a hemispherical shape. The central part 12b (peripheral part 12a) of the lid part 12
The inner part) may be formed in advance by press molding or the like so as to protrude outward in a spherical shape, as shown in FIG.

The sealed container of the present invention and the sealed container manufactured by the method of the present invention have the advantage that there is no risk that the lid portion heat-sealed to the flange portion of the container body will peel off and the sealing performance will be lost.

[Brief explanation of the drawing]

1, 2, 3, 1l-1t are vertical cross-sectional views of examples of conventional sealed containers, in which FIG. 1 shows the state immediately after sealing, and FIG.
The figure shows a state in which the internal pressure of the sealed diameter has just increased, FIG. 3 shows a state after a while has elapsed after the internal pressure has increased, and FIG. 4 shows a state in which the lid of the sealed container shown in FIG. FIG. 5 is a vertical cross-sectional view of a sealed container according to the first embodiment of the present invention, and FIG. 6 is an enlarged vertical cross-sectional view of part A in FIG. 5. 7 is a partially cutaway front view showing an example of a heat fusion device for manufacturing the sealed container shown in FIG. 5, and FIG.
The figure is a vertical sectional view of the main part showing the state immediately before heat fusion is performed using the apparatus shown in FIG. 7, FIG. 9 is a longitudinal sectional view showing the state immediately after the sealed container of FIG. FIG. 10 is a vertical cross-sectional view of a main part of a sealed container according to a second embodiment of the present invention, and FIG. 11 is a view of a mold for forming a closing body, which is a member for manufacturing the sealed container of FIG. 10. It is a longitudinal cross-sectional view showing an example. 11, 31--container body, l 1 a, 31
a - Outer flange portion, 11x, 31x... Container main portion, 11x1. . 31X1...Outward protrusion, 12...Lid, 12a.
...Peripheral part, 12 x inner layer, 13, 33... Sealed container, 16°36... Annular groove, 16a... Opening, 17.37... Heat fusion part, 26... Ring body, 35
...Closed body, 46. Annular body.

Claims (3)

[Claims] (1) In a sealed container in which a lid portion whose inner layer is made of thermoplastic resin is joined to an outer flange portion of the container body, the outer flange portion has an opening on the inner circumferential surface of the outer flange portion; A layer having a shape corresponding to the peripheral edge of the lid part and forming at least the lower surface thereof is provided with an annular groove made of a thermoplastic resin that can be heat-sealed to the thermoplastic resin of the inner layer of the lid part, and the lid part A sealed container characterized in that an inner layer of the peripheral edge of the annular groove and a layer forming the lower surface of the annular groove are heat-sealed. (2) Place a flange-shaped outward protrusion in which the layer forming the top surface is made of thermoplastic resin on top of the outward protrusion of the main part of the container formed at the open end, and the outer diameter of the outward protrusion The outer diameter of the lid is smaller than the outer diameter of the lid, and at least the inner layer is made of a thermoplastic resin that can be heat-sealed with the thermoplastic resin of the layer forming the upper surface. The upper layer has an outer diameter and an inner diameter substantially equal to the outer diameter and inner diameter of the outwardly protruding portion, respectively, and the layer forming the lower surface is made of a thermoplastic resin that can be heat-sealed with the thermoplastic resin of the layer forming the upper surface. Place the ring body,
A method for manufacturing a sealed container, comprising heat-sealing an upper surface of the outwardly protruding portion, an inner layer of the peripheral edge of the lid, and a lower surface of a portion of the ring body that faces the outwardly protruding portion. (3) The layer forming the top surface is made of a thermoplastic resin and is placed on top of the outward projection of the main part of the container formed at the open end. The thermoplastic resin forming the annular body and the thermoplastic resin forming the annular body are formed into an annular body made of a thermoplastic resin that can be heat-sealed and whose outer diameter and inner diameter are approximately equal to the outer diameter and inner diameter of the outwardly protruding portion, respectively. The annular body of the closure body in which the peripheral edge of the lid having a fusible inner layer is embedded and at least the inner layer is thermally fused to the annular body is placed, and the annular body and the outwardly protruding part are placed. A method for manufacturing a sealed container characterized by heat-sealing.