JP2003175940A - Carbonated beverage bottle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carbonated beverage bottle made of a polyethylene terephthalate resin with a similar structure to that of a traditional lemonade bottle having a narrow portion in the middle of the bottle. <P>SOLUTION: A bottle having a narrow portion in the middle of the bottle and having an upper part and a lower part of the bottle communicating via the narrow portion is molded by biaxial oriented blow molding of a polyethylene terephthalate resin. In addition, an average thickness of the narrow portion is made to be 0.8 to 2.5 mm, whereby the bottle for lemonade is obtained, which has such strength that the narrow portion is fully resistant and practicable even if an internal pressure exceeds approximately 4 kg/cm<SP>2</SP>when a carbonated beverage such as lemonade is put in. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbonated beverage bottle, and more particularly to a so-called Ramune bottle using a spherical stopper member such as a glass ball housed inside the bottle as a stopper member.

[0002]

2. Description of the Related Art Among carbonated drinks, bottles having a unique structure are often used for so-called Ramunes. The bottle structure is such that the upper and lower portions of the bottle communicate with each other through a narrowed portion, a spherical stopper member made of glass beads is accommodated in the upper bottle portion, and the stopper member is prevented from falling to the lower portion of the bottle. It has a structure to prevent it. The bottle is plugged by pressing a spherical stopper member such as a glass ball against the upper end opening of the bottle by the pressure of carbonic acid in the bottle.

The bottle for Ramune having the above-mentioned structure has been made of glass in the past, but in recent years, bottles made of vinyl chloride resin have been mainly used in view of cost and handling. There is. A direct blow molding method is usually employed as a method for molding a bottle for a Ramune having a narrowed portion as described above with a vinyl chloride resin.

[0004]

By the way, vinyl chloride resin is inexpensive and exhibits excellent properties in terms of strength, etc. However, since hydrogen chloride gas is generated when incinerated, treatment and disposal when it becomes waste is a problem. Becomes Therefore, in recent years, vinyl chloride resins have gradually become less used for applications such as bottles for drinking water, and polyethylene terephthalate (PET) resins are often used for such applications.

However, a bottle for Ramune having a narrowed portion between the upper and lower portions of the bottle cannot be molded by PET in the prior art. That is, since the PET resin is cracked when the direct blow molding method is adopted when it is molded into a bottle due to the properties of the material such as strength in a state of being heated in a plastic state, it is generally 2 The axial stretch blow molding method is adopted. Here, in the biaxial stretch blow molding method, the shape and size of the parison are optimally set according to the shape and size of the molded product, the wall thickness, and the like. If the intermediate part has a constriction, and the size of the constriction is smaller than the outer diameter of the parison, the parison is crushed by the part corresponding to the constriction of the mold before molding, so It becomes impossible. Here, when molding a bottle for Lamune that is normally commercially available with an internal capacity of about 200 to 250 cc, the outer diameter of the parison is about 25 mm or less, and a glass ball or the like used for the bottle for Lamune is used. Since the outer diameter of the spherical plug member is generally about 16.5 mm, the inner diameter of the narrowed portion of the bottle needs to be smaller than that. Therefore, the bottle for Ramune cannot be molded by PET using the biaxial stretch blow molding method.

Therefore, it is conceivable to make the outer diameter of the parison smaller than the size of the narrowed portion, but in that case, the wall thickness of the parison cannot be changed so much for optimum blow molding. Due to the restrictions, the parison length must be increased in order to secure the required amount of resin. When the parison length is increased, the elongation rate when the parison is stretched by the stretching rod is reduced, and the required strength cannot be obtained. Eventually, even with such measures, a bottle for Ramune is molded using PET resin. You cannot do it.

[0007] From the above, conventionally, the resin Ramune bottle is made of vinyl chloride resin having a traditional structure having a narrowed portion in the middle of the bottle, or vinyl chloride resin is repelled. In this case, the material is PET, and a spherical stopper member such as a glass ball is used as a bottle for Ramune, but a bottle having a narrowed portion for preventing the bottle from falling to the bottom is used. However, the combination of a bottle that does not have a narrowed portion and a spherical stopper member such as a glass bead is inverted so that the spherical stopper member can be moved to the upper opening for capping after storing the contents in the bottle. When making it, the time required for the spherical stopper member to move from the bottle bottom to the opening is longer than that of the traditional structure located in the constriction,
There is a problem that the leakage of contents will increase.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a bottle of carbonated drink having a structure equivalent to that of a traditional Ramune bottle having a narrowed portion without using vinyl chloride resin. There is.

[0009]

In order to achieve the above object, the bottle for carbonated beverages of the present invention has a narrowed portion formed at a position of a predetermined size from an opening formed at the upper end, and the narrowed portion is interposed therebetween. The upper and lower parts of the bottle are in communication with each other, and the inner surface dimension of the narrowed portion is such that a spherical stopper member for accommodating the inside of the bottle and stoppering the opening by the pressure inside the bottle does not pass through. In the bottle for carbonated beverages, the material is polyethylene terephthalate, and the product is a biaxially stretch blow molded product, and the narrowed portion has an average wall thickness in the range of 0.8 to 2.5 mm. It is characterized by (claim 1).

Here, in the carbonated beverage bottle of the present invention, as a more specific structure thereof, the narrowed portion is formed by the two opposite wall portions of the bottle wall body protruding from the outside toward the inside. In addition, a structure in which a plurality of rib-shaped projections further projecting to the inner surface side are formed in the protruding portion can be suitably adopted (claim 2).

The present invention has been made as a result of earnest research on a method of molding a bottle having a narrowed portion for preventing the spherical stopper member from dropping in the middle portion of the bottle by using polyethylene terephthalate resin. For the first time, a bottle having a narrowed portion for preventing the spherical stopper member from falling is molded using PET resin.

That is, in the bottle for carbonated beverages according to the first aspect of the present invention, the PET resin is molded by the biaxial stretch blow molding method, and the average thickness of the narrowed portion is 0.8 to 2.5 mm. With this structure, even if the internal pressure exceeds about 4 kg / cm ² when storing carbonated drinks such as ramune, the stenosis can fully withstand and be put to practical use. Axial stretch blow molding can be performed. If the average wall thickness of the narrowed portion is less than 0.8 mm, the amount of expansion of the narrowed portion during the storage of the carbonated beverage is large, resulting in problems such as insufficient strength. The average wall thickness is 2.5m
When it exceeds m, not only the material cost becomes high, but also it becomes difficult to perform efficient biaxial stretch blow molding under good conditions with good reproducibility.

Further, as in the invention according to claim 2, a plurality of ribs are formed so that the bottle wall body is squeezed out from the outer side to the inner side to form a narrowed portion, and the squeezed portion is further protruded inward. If the protrusions are formed, the narrowed portion will be deformed due to the expansion due to the internal pressure when the carbonated beverage is stored, and the spherical plug member will pass through the narrowed portion and drop to the bottom surface of the bottle more reliably when the bottle is opened. can do.

The method for producing the bottle for carbonated beverages according to the present invention as described above is not particularly limited, but as a result of research conducted by the present inventors, the following method is suitable. It has been confirmed that That is, in order to enable molding of a bottle having a narrowed portion by the biaxial stretch blow molding method, the bottle can be moved forward and backward toward the inside of the mold body so as to face each other at the position corresponding to the narrowed portion.
In other words, by providing a pair of movable molds that can approach and separate from each other, and by separating the movable molds in the stretching process using the stretching rod and the primary blowing process, the optimum shape for molding the bottle to be obtained. -Even if a parison of a size is used, it is possible to prevent it from being crushed by the mold and to optimize its stretch ratio in the axial direction. Then, in the secondary blowing step, the movable mold is moved closer to the mold, and a blowing pressure higher than that in the primary blowing step is used to obtain a narrowed portion having a required size.

By adopting such a manufacturing method, the elongation rate in both the height direction and the diametrical direction of the bottle is 2 or more, and the inner volume is about 200 to 250 cc and the diameter is 16 which is commonly used as a bottle for Ramune. A bottle having a narrowed portion that does not allow the spherical stopper member of about 0.5 mm to fall can be manufactured from PET resin.
In addition, the PET resin of the invention according to claim 2 enables stable production.

[0016]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. 1 is a front view of a molded product of a bottle body 1 according to an embodiment of the present invention.
Is a left side view thereof, and FIG. 3 is a sectional view taken along line AA of FIG. Further, in FIG. 4, the plug packing 3 is attached to the bottle body 1.
A state in which the packing retainer 2 is incorporated and the spherical stopper member 4 is used for stoppering is shown in a sectional view of a main part.

The bottle body 1 is a molded product made of PET resin, and an opening 11 is formed at its tip, and a male screw 12 for mounting the packing holder 2 is formed on the outer periphery of the opening. . A step portion 13 for mounting the plug packing 3 is formed on the inner peripheral surface immediately below the opening 11.

A narrowed portion 14 is formed on the bottle body 1 at a position approximately ⅔ of the total height from the bottom surface thereof. The narrowed portion 14 divides the bottle body 1 into a bottle upper portion 1a and a bottle lower portion 1b which communicate with each other, and the spherical stopper member 4 made of glass beads is housed in the bottle upper portion 1a. The narrowed portion 14 is formed by two side surfaces of the wall of the bottle body 1 protruding from the outer side to the inner side, and the narrowed portion 14 is formed in the narrowed portion 14 as shown in FIG. Two rib-shaped projections 14a are formed on the opposite protruding portions so as to project further inward at two locations. The dimension of the narrowed portion 14 on the inner surface side of the bottle is a dimension that does not allow the spherical stopper member 4 housed in the bottle upper portion 1a to pass through. A recess 15 is formed in the wall of the bottle upper portion 1a for preventing the spherical stopper member 4 from rolling inside the bottle and reaching the opening 11 when the bottle is tilted when drinking the contents. ing.

The above-mentioned bottle body 1 is composed of 2 bottles as described later.
It is molded by the axial stretch blow molding method, but the portion above the line indicated by PL in the figure is the molding region by the injection molding method, and the portion above it is the blow molding region, and within that blow molding region. The average thickness of the narrowed portion 14 located is in the range of 0.8 to 2.5 mm, more preferably about 1.0 to 2.0 mm. The average thickness of the blow-molded region excluding the narrowed portion 14 is not particularly limited and may be the same as that of a normal PET bottle, for example, the vicinity of the bottom of the bottle is about 0.8 to 2.0 mm, and others. Is about 0.3 to 0.8 mm.

The spherical plug member 4 is inserted into the bottle body 1 with the packing 3 and the packing retainer 2 removed.
In that state, the carbonated beverage is poured into the bottle body 1, the packing 3 and the packing presser 2 are attached, and the spherical stopper member 4 is extended to the opening 11 by inclining the bottle so that the opening 11 faces downward. By dropping, the spherical stopper member 4 is pressed against the packing 3 by the pressure of carbonic acid in the bottle to be in a stoppered state, as shown in FIG.

Next, an example of a method of manufacturing the bottle body 1 of the above embodiment will be described. First, a parison as shown in FIG. 5 is molded from PET resin by an injection molding method. By this injection molding,
A portion above the line PL shown in FIG. 1, that is, the opening 1
The final shapes such as 1, the male screw portion 12 and the step portion 13 are molded. Further, the outer diameter dimension D of the parison in the blow molding region is larger than the width dimension (W in FIG. 3) at the formation position of the protrusion 14a which is the minimum dimension of the narrowed portion 14 of the bottle body 1 after blow molding.

Next, the bottle body 1 shown in FIGS. 1 to 3 is produced by the biaxial stretch blow molding method using the above parison.
Molding. FIG. 6 is a longitudinal sectional view of an essential part showing a mold structure used for the biaxial stretch blow molding, FIG. 7 is an enlarged view showing a detailed structure of one moving mold 6a, and FIG.
FIG.

The mold body 5 is composed of a pair of side surface molding molds 5a, 5b and a bottom surface molding mold 5c which face each other. Moving dies 6a and 6b are attached to the side surface molding dies 5a and 5b, respectively. The movable dies 6a and 6b are side face forming dies 5a and 5b, respectively.
It is slidably supported by guide members 51a and 51b that are fixed to each other, and is movable in a direction in which the guide members 51a and 51b face each other and approach and separate from each other.

The movable dies 6a and 6b are displaced by the driving of drive mechanisms 7a and 7b provided in the die body 5. The drive mechanisms 7a and 7b are slidably supported by vertically oriented guides 71a and 71b, and rods 72a and 72b that are vertically displaced by a linear motion type actuator (not shown) such as a cylinder. And inclined cams 73a and 73b fixed to the lower ends of the rods 72a and 72b. As shown in FIGS. 7 and 8, a compression coil spring 61 is interposed between each movable mold 6a, 6b and the guide member 51a.
The a and 6b are biased so as to be separated from each other. Further, each movable mold 6a, 6b is provided with a roller 63 rotatable about a shaft 62, and the roller 62 is always driven by the biasing force of the compression coil spring 61 so that the sloped cams 73a, 73 are provided.
It is pressed against the slope of b. With such a configuration, the movable dies 6a and 6b approach each other by driving the actuators of the drive mechanisms 7a and 7b to move the sloped cams 73a and 73b in the vertical direction.
Displaces in the direction of separation.

A blow core 8 is provided below the die main body 5, and the center of the blow core 8 is a stretch rod 81.
Has penetrated. The parison shown in FIG. 5 is inserted into the mold body 5 after being heated to the temperature necessary for blow molding, with the outer periphery of the male screw portion 11 being held by the blow core 8. When heating this parison, the constriction 1
The temperature distribution of each part of the parison is set so that the average wall thickness of each part of the bottle including No. 4 falls within the above range. When inserting the parison into the mold body 5, the sloped cams 73a and 73b are raised to move the movable mold 6
The a and 6b are set back (separated). As a result, the outer peripheral surface of the parison does not come into contact with the movable molds 6a and 6b.

In blow molding, each movable mold 6a,
The parison opening 11 with 6b retracted (separated)
A parallax is stretched in the axial direction by inserting a stretching rod 81 from the inside, and after performing a primary blowing step of blowing air into the parison under a predetermined pressure, each slope cam 73
By moving a and 73b downward, the moving molds 6a and 6b
A secondary blow step of advancing (approaching) b and blowing higher pressure air in that state is performed. By adopting such a process, even if the minimum dimension W in the narrowed portion 14 of the bottle body 1 is smaller than the outer diameter D of the parison, molding is not hindered and a molded product with good reproducibility can be obtained. You can

As a specific example, the parison has an outer diameter D of about 25 mm and the narrowed portion 14 has a minimum dimension W of 11 mm.
As the parison, the parison is housed in the mold body 5 without contacting the movable molds 6a and 6b, and the stretching rod 8 is used.
1, the longitudinal stretching ratio is 2.2, the blowing pressure in the primary blowing process is 10 kg / cm ² , the blowing pressure in the secondary blowing process is 40 kg / cm ^{2, and the} lateral stretching ratio is 2.8. A PET bottle having an average wall thickness of about 1.5 mm, an average wall thickness near the bottom of the bottle of about 1.2 mm, and an average wall thickness of the other bottle walls of about 0.5 mm is molded accurately with good reproducibility. I was able to.

In the bottle body 1 thus obtained,
The spherical stopper member 4 made of glass beads is housed in the bottle upper portion 1a, and the packing 3 and the packing retainer 2 are provided in the opening 11.
When the inside is filled with a carbonated beverage and capped with the spherical stopper member 4, the spherical stopper member 4 has sufficient strength to withstand an internal pressure of carbonic acid of more than 4 kg / cm ² , and also due to the expansion due to the internal pressure, There was no problem that the narrowed portion 14 was plastically deformed and the spherical stopper member 4 dropped after opening.

In the above manufacturing method, the mold structure for the biaxial stretch blow molding is not particularly limited to the structure described in the above-mentioned embodiment, and especially the moving molds 6a, 6b. It is needless to say that any other known mechanism can be adopted as the drive mechanism 7 of FIG.

Further, the shape of the narrowed portion 14 is not limited to the shape of the above-described embodiment, and the number and position of the rib-shaped projections 14a which are projected inward can be set arbitrarily. In the present invention, the average thickness of the narrowed portion 14 is 0.8 even if the rib-shaped projection 14a is not provided.
The required strength can be obtained by setting the thickness to 2.5 mm, but the strength can be further increased by forming the rib-shaped protrusion 14a.

[0031]

As described above, according to the present invention, a polyethylene terephthalate resin is used for a so-called Ramune bottle having a structure in which a spherical stopper member does not pass through in the middle portion of the bottle. The average thickness of the narrowed part of the bottle consisting of 0.8-2.5m
By setting m, the internal pressure is 4k due to the filling of carbonated drinks.
For the first time, it was possible to obtain a practical PET bottle made of Ramune having a strength sufficient to endure even when it exceeds g / cm ² .

Further, by providing a rib-shaped projection projecting inwardly in the narrowed portion for preventing the spherical stopper member from falling, it is possible to suppress the amount of deformation due to the internal pressure when the carbonated beverage is filled, It is possible to more reliably prevent the spherical stopper member from dropping to the bottom of the bottle due to plastic deformation.

[Brief description of drawings]

FIG. 1 is a front view of a bottle body 1 according to an embodiment of the present invention.

FIG. 2 is a left side view of FIG.

3 is a cross-sectional view taken along the line AA of FIG.

FIG. 4 is a cross-sectional view of essential parts showing a stoppered state of a bottle using the bottle body 1 according to the embodiment of the present invention.

FIG. 5 is a partial cross-sectional view showing the structure of a parison used for biaxial stretch blow molding of the bottle body 1 according to the embodiment of the present invention.

FIG. 6 is a vertical cross-sectional view showing the structure of a mold used in the biaxial stretch blow molding process of the bottle body 1 according to the embodiment of the present invention.

7 is an enlarged cross-sectional view showing a detailed structure of a moving die 6a of the die shown in FIG.

8 is a cross-sectional view taken along the line AA of FIG.

[Explanation of symbols]

1 bottle body 11 openings 12 Male screw 13 steps 14 Stenosis 14a protrusion 2 Packing holder 3 packing 4 Spherical stopper 5 Mold body 5a, 5b Side forming mold 51a, 51b guide member 6a, 6b moving mold 61 Compression coil spring 63 Roller 7a, 7b drive mechanism 71a, 71b guide 72a, 72b rod 73a, 73b Slope cam 8 blow core 81 Stretching rod

Continued front page    F-term (reference) 3E033 AA01 BA18 CA04 DA03 DB01                       DC10 DD04 FA02 FA03 GA02                 3E062 AA09 AB02 AC02 KB02 KB15                       KB17 KC01                 4F208 AA24 AG07 AG22 AG25 AG28                       AH55 AR12 LA02 LA04 LD06                       LG28 LN01 LN23

Claims (2)

[Claims] 1. A narrowed portion is formed at a position of a predetermined size from an opening formed at the upper end, the upper part and the lower part of the bottle communicate with each other through the narrowed part, and the inner surface dimension of the narrowed part. Is a bottle for carbonated drinks, which is accommodated in the upper part of the bottle and does not drop the spherical stopper member for stoppering the opening due to the pressure inside the bottle, wherein the material is polyethylene terephthalate and biaxially stretched. A bottle for carbonated beverages, which is a molded product by a blow molding method, wherein the narrowed portion has an average wall thickness in the range of 0.8 to 2.5 mm. 2. The narrowed portion is formed by two portions of the bottle wall body facing each other protruding from the outside toward the inside, and the protruding portion has a plurality of protrusions further inward. The bottle for carbonated drink according to claim 1, wherein a rib-shaped projection is formed.