JPS581606A - Sealing packing method - 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 The present invention relates to a packaging method for filling heated contents into a kelp-like plastic container and sealing the container. More specifically, the present invention relates to a hermetically sealed packaging method in which a heat source of a liquid food or the like is filled into a small-walled plastic container, the container is completely sealed, and then the container is cooled.

Glass bottles have been used for a long time as containers for liquid foods such as alcoholic beverages and juices, but glass bottles have the drawbacks of being fragile and heavy, so lightweight liquid containers have recently attracted attention as an alternative to glass bottles. It has been done. Metal cans such as aluminum cans are widely used as lightweight liquid containers, but since metal cans are difficult to reuse or incinerate, there is a problem in disposing of empty cans after use. Glass containers or paper-plastic composite containers are excellent as containers for liquids because they are light, economical, and easy to incinerate after use.9 However, with recent improvements in functionality, glass bottles and metal cans are increasingly being replaced. Substitutions are progressing.

In order for glass containers and paper-glass composite containers to become more popular as liquid containers, it is necessary to reduce the thickness of glass containers without sacrificing performance in terms of resource and energy conservation. . When the wall thickness of a plastic container is made thinner, the inner surface, which is lighter in weight, has less rigidity, and the strength of the plow body is lost in some places.

Therefore, when a thin-walled plastic container is filled with contents and the bale opening is sealed, the outer wall of the container may become depressed due to the influence of atmospheric pressure, resulting in poor appearance. Especially when heating liquid foods, etc.
When it is filled into a thin-walled plastic container, the mouth of which is sealed, and cooled, the pressure inside the container is reduced, causing the container to gradually dent. For example, if a cylindrical cup-shaped thin-walled glass container is filled with liquid at high temperature, the mouth of the container is sealed with a lid, and then cooled, the side wall of the container will dent and the container will deform into the shape of a rectangular container. It's coming. The same goes for square containers.
When the container is filled at high temperature, sealed, and then cooled, the side wall of the container body becomes depressed.

In order to overcome these drawbacks of thin-walled plastic containers like kelp, it is possible to consider a method of keeping the internal pressure of the container high and sealing it.

However, in order to employ such a method in high-temperature filling, etc., special equipment is required.

The present inventors have developed various methods that do not cause dents in the walls of the container body even after heating and filling liquid food into a thin-walled plastic container, sealing the mouth with rice, and then cooling the container. As a result of the study, it was discovered that deformation of the wall part could be prevented by utilizing the deformation of the bottom of the body of the sealed container to relieve the depressurization caused by cooling inside the container, and after further study, the present invention was completed. Nine.

SUMMARY OF THE INVENTION It is an object of the present invention to provide an improved method for filling, sealing, and cooling a pot-shaped thin-walled plastic container with heated contents.

The present invention 011 sealing and packaging method is a method of filling the contents into the main body of a kelp-like thin-walled plastic container and sealing the mouth of the main body with a lid. A concave state in which most of the lid is recessed toward the inside of the container is the most dynamically stable shape.
9 has such rigidity that the convex state in which most of the lid protrudes to the outside of the container is a mechanically quasi-stable shape, and the intermediate state between the concave state and the convex state is a mechanically unstable shape. With a container having a certain bottom and/or major part, at least the main body of which is thin-walled plastic, the bottom and/or main part of the main body of the container is pre-determined.
t7' Press the top S of the container to transform it from the -legged state to the convex state, fill the heated contents into the container body, and then completely seal the mouth of the main body with the lid of the container. After that, the contents are cooled to return the bottom and/or large portion of the scissors from a convex state to a concave state. It's a #sign.

Hereinafter, the present invention will be explained in detail with reference to the drawings.

FIG. 1 shows an example of the nine-tight packaging method according to the present invention, and shows the liquid filling and sealing steps in order from Le) to (•) in a side view. In the figure, (1) is the main body of a cup-shaped thin-walled plastic container, (2) is the bottom of the container main body, and (8
) is the granger used to press the wrinkled bottom (2), (
4) is the container fixing base, (5) is the bottom that is pushed by the plunger (3) and transformed from a concave state to a convex state, (6) is a knob that supplies the liquid to be filled, and (7) is the liquid content. , (8
) shows the lid of the container, (9) shows the seal between the container body (1) and * (8), and (1 shows the bottom restored to the concave state).

The filling and sealing steps of liquid contents from (1) to (・) are as follows.

First, as shown in (a), place the main body (1) of the cup-shaped thin-walled glass container on the fixed stand (4), and place the bottom of the container main body (1) with the granger (3) as shown in (1)). to deform the bottom from the most stable concave state D (2) to the mechanically quasi-stable convex state (5) K. Then, as in (6),
Heat the round liquid contents (7) from the supply I4if (6)! −
Fill into the container body. Fill the container body with the contents and place the lid (8) over the mouth as shown in (d).
Place it in the container and seal it with the seal part (9) of the container body. When the contents are cooled, the pressure inside the sealed container decreases, and the atmospheric pressure pushes the container wall, causing the bottom of the container, which was convex in (d), to become convex as in (e). Return to concave state.

As a result of the steps in the sealed packaging method that are the first cause, the sealed container shown in (e), whose bottom has returned to its concave state, does not tilt or fall even when left standing with the bottom facing down. , stable. The bottom of the container is convex (d) Since the bottom of the sealed container shown in K is round and protrudes, it is unstable, tilts, and easily falls over.

FIG. 2 shows an example of the sealed packaging method of the present invention using a container in which most of KFi, It is deformed. The liquid filling and sealing steps are shown in side views in order from (a) to (1).

In the figure, (11) is the main body of a cup-shaped thin plastic container, (12) is a thin plastic lid that is mostly concave and has a stable shape, and (13) is a container that supplies the liquid content. (14) is the liquid content, (15) is the lid forcibly transformed from a stable concave state to a metastable convex state, (1
6) shows the sealed portion between the container body and the rice, (17) shows the rice having a convex shape, and (18) shows vIk that has returned to a stable concave shape.

*In 2E, first, as shown in (b), supply 14if (13) t I! into the container body 0υ. The liquid contents (
14). Next, Ii (15), which has been forcibly transformed from the concave state (12) to the convex state, is <c>
Place 72 parts (16) on the mouth of the container body as shown.
Seal with. When the contents are cooled, the pressure inside the sealed container decreases, and the atmospheric pressure pushes the wall of the container, causing the large part of the lid (17) that was convex to become concave as shown in (1). return.

In the present invention, the pot-shaped thin-walled glass container is
A deep-drawn concave container with a molding depth to diameter ratio of 1 to 3, and a wall thickness of the container body of 0.1 to 1.5.
Preferably, it is molded from a thermoplastic glass material within the range of m. The main body of the thin-walled plastic container in the form of a top is not limited to a single-layer plastic container, and may be a paper tube or a container made of a composite of a paper top and a plastic container. Although the internal volume of the container is not limited, it is particularly effective for containers with a capacity of 100 cc to 1,000 cc.

The material of the container is thermoplastic, among which are moderately rigid polyglopylene, high density vertical polyethylene, low density polyethylene, polyethylene terephthalate,
Resins whose main components are tetravinyl chloride, polystyrene, polycargonate, etc. are preferred. The molding method for the container body is
Thin-walled containers manufactured by sheet thermoforming methods, injection molding methods, blow molding methods, etc. are particularly preferred.

The container is filled with heated contents, and the method of the present invention is particularly suitable for filling heated liquid foods. For sterilization or sterilization, food is heated and filled into containers. If you fill a thin-walled plastic container with food heated to a temperature between 0°C and 95°C and seal the mouth, the contents will not spoil.
It can withstand long-term storage.

When heated food is filled into a thin-walled plastic container, the mouth is sealed, and the container is cooled, the air pressure inside the container decreases, creating a vacuum. Become.

Particularly in the case of a cylindrical container, a portion of the cylindrical wall of the container body may be recessed, giving it the appearance of a square container. In deep, cup-shaped containers, dents caused by reduced pressure are particularly noticeable. The present invention is effective as a method for absorbing deformation of the container body due to such reduced pressure inside the container.

In the present invention, a concave state in which the bottom of the container body and/or most of the lid is depressed toward the inside of the container is the most dynamically stable shape. The convex state protruding to the outside of the container is a mechanically quasi-stable shape, which is To9.
, the intermediate state between the concave state and the convex state is a dynamically unstable shape. In order to create a bottom or large part with these properties, the bottom or large part must have appropriate rigidity.
In addition, rigidity is also required at the bottom or most of the surrounding area. The reason why a shape intermediate between a concave state and a convex state is dynamically unstable is that when the shape is in the middle, a force that tries to expand the peripheral area from the bottom or the center of the main part toward the periphery □ direction is This is because, while it acts, there are forces from the surroundings that resist it. If the rigidity is small and soft from the center of the bottom or the main part to the surrounding area, it will be in a concave state,
The stability of the convex state and its intermediate state is not determined, and no special force is generated to maintain the shape of the container.

In order to deform the bottom of the container body or most of the lid from a concave state to a convex state and then restore the original concave state, there is a preferable range for the thickness and elastic modulus of the deformed portion. The wall thickness of the bottom or most part of the deformation ranges from 0.1 vm to 1.
Approximately 5 ■ is preferable. If the wall thickness of the bottom or most part of the container to be deformed is less than 0.1 mm, there may be insufficient force to restore the container from a convex state to a concave state when filled with contents.

If the thickness of the bottom or most part is 1.5 mm or more, it may be difficult to press and deform the convex lIK from the concave state at first. The bending elastic modulus of the material constituting the deformable bottom or major portion is 0.1 x 10'l14/- to 3 x
It is preferably within the range of 10' Kt/d. The elastic modulus of the song is 0. The elastic restoring force is weak for materials with I
Materials with a value of /a1 or higher are too hard.

When filling the main body of a thin-walled plastic container with a concave bottom at high temperature, the material of the lid used to seal the mouth may be plastic, paper, metal, etc., and is not particularly specified. The method of the present invention is suitable for sealing the mouth of a container body by seaming it with a metal lid such as an Arun lid, similar to the seaming of the mouth of a metal can.

Examples are shown below.

Example: Hot water heated to 85°C was poured into the main body of a round cup-shaped polyzolopyrene resin container with a diameter of 60 cm and a depth of 100 cm.
The container was filled using the same process as shown in the example of FIG. 1, and a lid made of 4-lipropylene resin was placed on the opening and heat-sealed.

The average wall thickness of the 1II11 part of the main body of the polypropylene resin passenger device is 0°2■, and the average wall thickness of the concave bottom part is 1.2■ in the center and 0.4■ in the peripheral part. have.

The container body was formed from a 2-inch thick sheet by thermoforming. The lid is a disc-shaped 4-lipropylene sheet with a wall thickness of 0.5 cm.

First, place the container body on the container fixing table as shown in Figure 1, press the bottom of the container body with a glass/jar to transform the bottom from a concave state to a convex state, and then heat it to 85 qcK to make water run. Injected into the container body. After filling with water, a lid was placed on the mouth and heat-sealed with the flange of the container body. Next, when the container is cooled, as the water inside the container is cooled, the water and remaining air inside the container contract, and the pressure inside the container is reduced, so that the bottom returns to its concave shape.9.

The package, which is hot-filled with water and has a sealed mouth, has a good appearance with no dents on the side wall.
Since the center is concave, it can stand stably.

For comparison, a polyzolopyrene resin container with the same dimensions and a flat bottom was filled with 85°C water in the same manner and heat-sealed with the same lid.9. After cooling, there was a large dent in the side wall of the butterfly container in the sealed package.

[Brief explanation of the drawing]

FIG. 1 shows an example of the sealed packaging method according to the present invention.
The liquid filling and closing process S is shown in side view in order from turtle to e't. In the figure, the main body of an LTL cup-shaped thin-walled plastic container,
2 is the bottom of the container body, 3 is a plunger used to push the bottom, 4 is a container fixing stand, 5 is the bottom pushed by a glass/jar and transformed from a concave state to a convex state, and 6 is a supply of liquid. 7 is the liquid content, 8 is the container's contents, 9 is the sealing part, and 10 is the nine-bottom part restored to the concave state. FIG. 2 shows an example of the sealed packaging method of the present invention using a container whose lid is largely deformed, and shows the liquid filling and sealing steps in order from a to d in side views. In the figure, 11 is the main body of a cup-shaped thin plastic container, 12 is a thin plastic lid that is mostly concave, 13 is a pipe for supplying liquid, 14 is the liquid content, and 15 is a convex container. The deformed lid includes a seal portion 16, a convex lid 17, and a concave lid 18. JP-A-58-1606 (5) Ω Figure a b 2 d

Claims (1)

[Claims] In a method of filling the contents into the main body of a top-shaped thin plastic container and sealing the mouth of the main body with a lid, the bottom and/or the top of the top-shaped main body of the container are such that most of the lid is inside the container. A concave state concave to the inside is the most dynamically stable shape, and a convex state where the bottom of the main body and/or most of the rice protrudes to the outside of the container is a mechanically quasi-stable shape. , a container having a rigid bottom and/or a large portion whose shape is mechanically unstable in the intermediate state between a concave state and a convex state, and at least a main body made of thin-walled plastic is used. The bottom of the main body of the container and/or the top of the lid are pressed in advance to transform the container from a leg circumferential state to a convex state, and the contents are heated and filled into the container main body, and then the cough main body is A hermetically sealed packaging method characterized by completely sealing the mouth part with a bag of a shell container, and then cooling the contents to return the bottom and the large part of the container from a convex state to a concave state.