JPH11278404A - Method and system for filling resin bottle with contents and structure for sealing up resin bottle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a filling method that is capable of restraining thermal deformation within a tolerance even though whitening and crystallization at the mouth are eliminated. SOLUTION: Blow mold is executed with a preformed body 10 set in a pair of metal molds 11 and 12, and the trunk part 20b of a bottle 20 is brought into contact with the metal molds 11 and 12 and heat setting for improving thermal resistance is applied. The percentage of water content for the preformed body 10 on an occasion of putting in the metal molds 11 and 12 is limited to a level of 2,500 p.p.m. or below. Polyethylene terephthalate resin is desirable as a material for the preformed body 10. After completion of heat setting, the bottle 20 is taken out of the metal molds 11 and 12 and then the bottle 20 is transferred to a filling part 2 and filled with contents 4. The time from taking out of the bottle 20 from the metal molds 11 and 12 to completion of filling of contents 4 at the filling part 2 is set to be less than 20 minutes, or desirably less than 15 minutes or desirable further to be less than 10 minutes.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for filling contents such as beverages into a resin bottle, a filling system, and a sealing structure suitable for the filling method and system.

[0002]

2. Description of the Related Art Methods of filling beverages requiring high-temperature sterilization into resin bottles include heating the beverages at a high temperature and filling the beverages, thereby simultaneously filling and sterilizing the bottles. There is a method of filling the object at a low temperature and then sterilizing the bottle by applying a hot water shower. These methods are properly used depending on, for example, the type of the contents.

[0003] In the above filling method, the bottle is heated to a high temperature, and if the bottle is not provided with sufficient heat resistance, the bottle may be thermally deformed. Further, in a conventional bottle, a metal cap is attached to the filled plug portion while being screwed, and the plug portion is sealed, so that the plug portion is required to have strength to withstand threading.

Therefore, conventionally, the plug portion is whitened and crystallized to improve its heat resistance and strength, and the body portion of the bottle is subjected to a heat treatment to improve its heat resistance (for example, Japanese Patent Publication No. 61-35056). No.).

[0005]

However, a bottle that whitens and crystallizes the plug consumes a large amount of heat energy in the production process and has low productivity as compared with a bottle that does not do this. This makes the bottle expensive. Also, in recent bottles, resin caps are used instead of metal caps from the viewpoint of suitability for recycling. Is reduced, and whitening and crystallization are not necessarily required only in terms of strength.

An object of the present invention is to provide a filling method and a filling system capable of suppressing thermal deformation within an allowable range even if omission of whitening and crystallization of the plug portion, and a sealing structure of the plug portion suitable for the same. Aim.

[0007]

Means for Solving the Problems In order to solve the above-mentioned problems, the inventors of the present invention conducted various studies on the heat resistance of the bottle, and as a result, the heat resistance of the resin bottle was determined by leaving the bottle unattended. It was found that the decrease in heat resistance correlated with the water absorption of the bottle. Since the molding of the bottle is performed in a mold heated to a high temperature, there is almost no absorption of moisture from the atmosphere, and when the bottle is taken out of the mold after molding and brought into contact with the surrounding atmosphere, the absorption of moisture is reduced. It was confirmed that the heat resistance gradually decreased at the beginning. Based on the above findings, the results of verifying the relationship between the elapsed time after molding the bottle and heat resistance,
After the bottle is molded, that is, when the filled bottle is taken out of the mold and exposed to the surrounding environment containing water, and the filling of the contents is completed within 20 minutes, the contents are heated to 95 ° C.
It was found that the deformation of the plug can be suppressed to an allowable range even at a high temperature.

[0008] In view of the above, an object of the present invention is to solve the above-mentioned problems by a method for filling the contents of a resin bottle, which completes filling the contents within 20 minutes after molding the resin bottle. And In particular, in the invention of claim 2, the temperature of the contents at the time of filling is limited to 95 ° C. or less.

According to the above invention, the filling of the contents is completed within 20 minutes after molding, so that the high-temperature contents can be sufficiently filled with the plugs without whitening and crystallizing the plugs of the bottle. High heat resistance is ensured, and there is no possibility of liquid leakage due to poor sealing due to deformation of the plug portion. In addition, within the range of less than 20 minutes after molding, the amount of water absorbed by the body of the bottle is small. Therefore, in the case where the body is heat-set to improve its heat resistance, the body is sufficiently deformed even if the heat-setting temperature is kept at 110 ° C. or lower (conventionally, about 150 ° C. at maximum). Can be prevented. Thereby, the time required for the heat setting process of the body can be shortened and the productivity of the bottle can be improved.

According to a third aspect of the present invention, in the method for filling the contents of a resin bottle according to the first or second aspect, the bottle is limited to a polyethylene terephthalate resin. In addition, the polyethylene terephthalate resin mentioned here includes what mixed a well-known additive in order to improve heat resistance. Thus, when the invention of claim 1 or 2 is applied to a bottle made of polyethylene terephthalate resin, thermal deformation of the bottle is reliably prevented.

According to a fourth aspect of the present invention, in the method for filling contents of a resin bottle according to any one of the first to third aspects, a plug portion of the bottle filled with the contents is covered with a resin cap. It is characterized by sealing.

The cap made of resin is easier to adapt to the plug of the bottle than the cap made of metal (for example, aluminum), and is less likely to damage the plug. For this reason,
When used to seal a plug that is not whitened and crystallized,
Liquid leakage due to deformation of the plug can be reliably prevented.

According to a fifth aspect of the present invention, in the method for filling the contents of a resin bottle according to any one of the first to fourth aspects, the water content of the plug portion of the preform at the time of molding the bottle is 25%.
It is characterized by being limited to 00p.pm or less. According to a sixth aspect of the present invention, there is provided a method for filling a content of a resin bottle in which a bottle is molded from a preform formed of a resin and the molded bottle is filled with the content. It is characterized in that the water content of the plug portion of the molded article is limited to 2500 p.pm or less.

These inventions have been obtained as a result of examining the preferable water content of the preformed body, focusing on the fact that the water content of the bottle immediately after molding correlates with the water content of the preformed body. In other words, a bottle formed from a preformed body that has excessively absorbed moisture may not be deformed even if the contents are filled immediately after the formation. On the other hand, when the water content at the stage of the preform is limited to 2500 p.pm or less, the bottle immediately after the molding has sufficient heat resistance to fill the high-temperature contents without whitening and crystallization of the plug. For a certain period of time after molding (for example, 2
If the filling is performed within 0 minutes, thermal deformation of the bottle can be reliably prevented.

According to a seventh aspect of the present invention, there is provided a molding part for molding a bottle from a preform made of resin, and a filling part for filling the molded bottle with contents. The above-mentioned problem is solved by a filling system for a resin bottle, wherein the time from the end of molding to the completion of filling in the filling section is set within 20 minutes.

According to the present invention, deformation of the bottle can be prevented in the same manner as in the method of the first aspect.

The invention according to claim 8 is a sealing structure for a resin bottle in which a plug portion of the resin bottle filled with contents is sealed with a resin cap. The above-mentioned problem is solved by a resin bottle sealing structure characterized in that a projection is formed to abut on the inner peripheral surface of the plug to prevent shrinkage of the plug.

According to the present invention, the cap of the bottle is supported from the inside thereof by the projection of the cap, thereby preventing shrinkage. Therefore, when the method is applied to a method or a system for filling high-temperature contents without whitening and crystallization of the plug portion,
Liquid leakage due to shrinkage of the plug after filling can be reliably prevented.

[0019]

FIG. 1 shows the main steps of a filling system to which the present invention is applied. This system is
A pair of molds 1 in which the preform 10 is heated to a predetermined temperature
The molding part 1 which is loaded into the insides 1 and 12 to perform blow molding, and the contents 4 (for example, fruit juice beverage) from the nozzle 21 to the bottle 20
And a filling section 2 for filling the liquid. Mold 1 of molding part 1
Plug part 10a of preform 10 mounted in 1, 1
Is not whitened and crystallized. Bottle 2 for blow molding
The 0 body portion 20b comes into contact with the molds 11 and 12 and is subjected to heat treatment (heat setting), thereby improving the heat resistance of the body portion 20b. The water content of the preform 10 when it is mounted on the dies 11 and 12 is limited to 2500 p.pm or less, preferably 2000 p.pm or less. The material of the preform 10 is preferably a polyethylene terephthalate resin. However, an additive for improving heat resistance may be mixed.

After the heat setting, the molds 11 and 12 are opened and the bottle 20 is taken out. The taken out bottle 20 is transferred to the filling section 2 by the predetermined transfer means 3.
Note that the transfer means 3 may be installed in a normal room temperature environment.

After removal from the molds 11 and 12, the bottle 20 removed from the molds 11 and 12
The time from the first contact with the moisture-containing atmosphere outside of 1, 12 to the completion of the filling of the contents 4 in the filling section 2 is within 20 minutes, preferably within 15 minutes, and more preferably within 10 minutes. Is set to Thus, even if the plug 20a of the bottle 20 is not whitened and crystallized, the contents 4
Can be heated to 60 ° C. to 95 ° C. to fill the bottle 20.

After the contents 4 are filled, as shown in FIG. 2, the cap 20 made of resin is attached to the plug 20a to seal the plug 20a. The cap 5 has a spout 20a
A projection 5a that contacts the inner peripheral surface 20c is formed. The protrusion 5a is preferably a ring-shaped member that goes around the inner peripheral surface 20c of the plug 20a. And the plug 5 is provided on the projection 5a.
Oa is given sufficient rigidity to prevent shrinkage. Thereby, liquid leakage due to generation of a gap between the outer periphery of the plug portion 20a and the inner periphery of the cap 5 can be prevented.

With respect to the bottle 20 used in the above-described system, the plug portion 20a and the body portion 20 are changed while the storage time after molding (the time until the contents are filled) is variously changed.
Tables 1 and 2 show the results of evaluating the heat resistance of b. The heat resistance of the plug 20a is determined by filling the inside of the bottle 20 with 90 ° C. hot water, sealing the plug 20a with the cap 5 (provided that the projection 5a is omitted), and then 20 was allowed to cool naturally in a lying state, and the presence or absence of liquid leakage after 24 hours was confirmed and evaluated. Also, the trunk 20b
Was determined based on whether or not deformation of the panel surface (side surface) of the trunk portion 20b was within an allowable range. Bottle 2 before hot water filling
0 storage environment is 22 ° C, relative humidity 60%, bottle 20
The molding conditions were 2 seconds for a mold temperature of 90 ° C. The minimum thickness of the plug 20a of the bottle 20 is 2.16m
m.

[0024]

[Table 1]

[0025]

[Table 2]

From the above results, it was confirmed that if the filling was completed within 20 minutes after the bottle was formed, liquid leakage could be reliably prevented.

[0027]

As described above, according to the filling method and the filling system of the present invention, the filling of the contents into the resin bottle is completed within 20 minutes after the molding of the bottle. Even when the plug is not whitened and crystallized, the bottle at the time of filling has sufficient heat resistance, and can be filled with high-temperature contents without deforming the bottle. In particular, the present invention can surely exert its effect on a bottle made of polyethylene terephthalate resin, and if the plug portion of the bottle filled with the content is sealed with a resin cap, the plug portion after filling is filled. The liquid leakage due to the deformation can be more reliably prevented.

When the water content of the plug portion of the preform at the time of forming a bottle is limited to 2500 ppm or less, the hot plug can be filled with high-temperature contents without whitening and crystallization of the plug portion. Can be reliably imparted to the bottle immediately after molding.

Further, according to the sealed structure in which the plug of the bottle is supported from the inside by the projection of the cap and the shrinkage of the plug is prevented, the hot contents can be removed without whitening and crystallization of the plug. When applied to filling methods and systems,
Liquid leakage due to shrinkage of the plug after filling can be reliably prevented.

[Brief description of the drawings]

FIG. 1 is a view showing main steps of a filling system to which the present invention is applied.

FIG. 2 is a diagram showing a state in which the plug portion of the bottle is sealed after the filling of the contents is completed in the system of FIG. 1;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Molding part 2 Filling part 3 Conveying means 4 Contents 5 Cap 5a Protrusion part 10 Preformed body 10a Plug part 11,12 Die 20a Plug part 20b Body part 20c Inner peripheral surface 21 of nozzle part Nozzle

Claims (8)

[Claims] Claims: 1. A resin bottle is molded 20 times after molding.
A method for filling the contents of a resin bottle, wherein the contents are filled within minutes. 2. The method for filling the contents of a resin bottle according to claim 1, wherein the temperature of the contents at the time of filling is 95 ° C. or less. 3. The method for filling the contents of a resin bottle according to claim 1, wherein the bottle is made of polyethylene terephthalate resin. 4. The method for filling the contents of a resin bottle according to claim 1, wherein the plug portion of the bottle filled with the contents is sealed with a resin cap. . 5. The resin bottle according to claim 1, wherein the water content of the plug portion of the preform at the time of molding the bottle is limited to 2500 p.pm or less. Contents filling method. 6. A method for filling a content of a resin bottle in which a bottle is formed from a resin preform and the content is filled in the formed bottle. A method for filling the contents of a resin bottle, wherein the water content of the stopper is limited to 2500 p.pm or less. 7. A molding section for molding a bottle from a resin pre-molded body, and a filling section for filling the molded bottle with contents, from the time when the molding section finishes molding the bottle. A system for filling a resin bottle, wherein a time until the filling in the filling section is completed is set within 20 minutes. 8. A sealing structure for a resin bottle in which a plug portion of a resin bottle filled with contents is sealed with a resin cap. A sealing structure for a resin bottle, wherein a projection is formed to abut on a peripheral surface to prevent shrinkage of the plug.