JP2001031010A - Filling and sealing method of content in synthetic resin bottle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the excellent condition of the filling line, and to prevent the uneasy visibility and degradation of customers' interest by sealing a container when the level of the residual liquid nitrogen in a head space in a specified range. SOLUTION: The head space of a polyester bottle having the content of 500 ml is set to be about 20 ml. Liquid nitrogen is filled in the head space so as to satisfy the formula W/S = 2 to 5, where W is the volume of the liquid nitrogen after evaporation, and S is the volume of the head space. Then, a mouth part of the synthetic resin bottle is sealed using a plastic cap, a metal cap or a sealing material when the volume of the residual liquid nitrogen in the head space is set to be 1/4 to 3/4. Further, by filling liquid nitrogen and blowing the mouth part of the synthetic resin bottle with nitrogen gas, the level of the content or the filled liquid nitrogen is oscillated to improve the evaporation efficiency of the liquid nitrogen.

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 and sealing the contents of a synthetic resin bottle, and more particularly to a method for reducing the material used by reducing the thickness of the synthetic resin bottle and preventing deformation due to reduced pressure. The present invention relates to a method for filling and sealing contents in a synthetic resin bottle.

[0002]

2. Description of the Related Art Conventionally, a polyester bottle obtained by biaxially stretch-blowing a preform made of a polyester resin such as polyethylene terephthalate has excellent transparency, impact resistance, gas barrier properties, etc., and is widely used in various beverages and liquid seasonings. Has been adopted.

[0003] Laminated bottles composed of a laminate of high-density polyethylene and an ethylene-vinyl alcohol copolymer are widely used in liquid seasonings, for example, edible oils.

In order to prevent deformation of a synthetic resin bottle due to reduced pressure, Japanese Patent Publication No. 1-11088 for supplying nitrogen to an edible oil bottle, or encapsulation in a non-carbonated beverage such as juice or mineral water is disclosed in Japanese Patent Application Laid-Open No. H06-209,873. -26319
No. 0 has been proposed.

[0005]

However, Japanese Patent Publication No. 1-14108 and JP-A-6-263190 merely aim to prevent deformation of a synthetic resin bottle by depressurization. It was still unsatisfactory in terms of the line of sight, the point of preventing deformation at the time of decompression when the thickness was reduced, and the efficiency of gas replacement in the head space after sealing.

[0006]

According to the present invention, after filling a synthetic resin bottle with the contents, the liquid nitrogen whose volume at the time of vaporization is equivalent to 2 to 5 times the volume of the head space is added to the head. A method for filling and sealing the contents into a synthetic resin bottle is provided which fills a space and then seals when the remaining amount of liquid nitrogen in the head space becomes 1/4 to 3/4.

Further, according to the present invention, there is provided a method for filling and sealing contents in a synthetic resin bottle according to the present invention, wherein liquid nitrogen is filled and the mouth of the synthetic resin bottle is blown with nitrogen gas. You.

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, after filling a synthetic resin bottle with contents, liquid nitrogen is filled into a head space formed above the bottle.

Usually, the head space of a polyester bottle having a content of 500 ml is about 20 ml, and the amount of liquid nitrogen filled in the head space is the volume W after vaporization of the liquid nitrogen and the volume S of the head space. Are filled so that the relationship between them becomes W / S = 2 to 5.

When the W / S is less than 2, an internal pressure for preventing the deformation of the synthetic resin bottle and a sufficient gas amount for replacing the air in the head space with nitrogen are obtained. Absent.

On the other hand, if the W / S exceeds 5, the supply amount of liquid nitrogen is too large, depending on the sealing timing, and the line of sight is lowered, which lowers the customer's visual anxiety and willingness to purchase.

Then, after filling with liquid nitrogen, when the remaining amount V of liquid nitrogen in the head space is reduced to 1/4 to 3/4, a plastic cap, a metal cap, a sealing material or the like is used to make a synthetic resin. Seal the mouth of the bottle.

When V is less than 1/4, a predetermined positive pressure cannot be obtained. On the other hand, when V is more than 3/4, the supply amount increases and after the vaporization, Gas replacement efficiency becomes worse.

In the present invention, there are various methods for filling the synthetic resin bottle with liquid nitrogen, such as flowing down, dropping, and spraying, but dropping is preferred from the viewpoint of sealing efficiency and the like.

In the present invention, the liquid nitrogen is filled, and the mouth of the synthetic resin bottle is blown with nitrogen gas to vibrate the liquid surface of the contents or the filled liquid nitrogen, whereby the liquid It is possible to improve the vaporization efficiency of nitrogen.

The synthetic resin bottle of the present invention includes:
Polyester bottle obtained by biaxially stretch-blowing a preform made of polyethylene terephthalate (PET), polybutylene terephthalate, or copolymerized polyester mainly composed of ethylene terephthalate units, or a laminate of high-density polyethylene and ethylene-vinyl alcohol copolymer A laminated bottle made of a body.

Then, when the polyester bottle is used,
Fruits, oolong tea, non-carbonated beverages such as mineral water, or edible oil, soy sauce, when filling the contents of liquid seasonings such as sauces, the filling of the contents above the Tg temperature of the polyester resin, about 70 ℃ It is desirable to do.

For example, non-carbonated beverages such as fruit juice, oolong tea and mineral water are filled aseptically at about 24 ° C.
On the other hand, edible oil is filled at a temperature of about 40 ° C., soy sauce is about 20 ° C., and sauce is about 65 ° C. at a temperature of Tg or less.

If the above-mentioned filling is carried out at a Tg temperature of about 70 ° C. or higher, the thermal motion of the polyester resin molecular chains becomes active, softens and deforms the polyester bottle, and the positive pressure cannot be maintained. It is not possible to reduce the thickness of the polyester bottle and prevent deformation due to reduced pressure.

Next, after filling the contents, liquid nitrogen is dropped into the head space of the polyester bottle and sealed with a plastic cap or the like. At this time, if a non-carbonated beverage such as fruit juice, oolong tea or mineral water is used, , 5
The internal pressure of the headspace at 25 ° C is 0.2 to 0.7 atm, while the internal pressure of the headspace at 25 ° C is 0.2 to 0.7 atm for liquid seasonings such as edible oil, soy sauce, and sauce.
Sealing is performed to 0.7 atm.

When a polyester bottle is used as the synthetic resin bottle of the present invention, the shape of the body is not particularly limited. When a panel that absorbs reduced pressure is provided on the body or a body, the body tends to protrude outward, and the cross section of the body 2 is circular as in the bottle 1 shown in FIGS. A shape in which the panel is not provided in the portion 2 is preferable.

The bottom shape is a shape in which a plurality of legs 4 projecting outward from the bottom 3 shown in FIGS.
A dome portion 5 in which the bottom portion 3 shown in FIGS.
Or a shape in which the bottom 3 shown in FIGS. 5 and 6 is recessed inward to form a plurality of reinforcing convex ribs 6.

Although not shown, the body 2 of the bottle 1 is provided with an annular reinforcing portion made of a concave groove, a convex bead or the like, in order to impart strength to the bottle after opening the plastic cap or the like.
It is preferable to provide the entire circumference or intermittently.

Hereinafter, an embodiment of the present invention will be described by applying to a polyester bottle.

[0024]

EXAMPLE 1 A preform made of polyethylene terephthalate having a basis weight of 30 g was biaxially stretch blow-molded to prepare a polyester bottle having an outer diameter of 28 mm and a content of 500 ml as shown in FIG. 1.

After filling each bottle with warm water at 40 ° C. below the Tg temperature of the polyethylene terephthalate,
Liquid space is 0.0 for headspace S = 20 ml
5 g (volume after vaporization W = about 44 ml) was added dropwise (W / S
= 2.2), and when the remaining amount of liquid nitrogen V reached ＝ (volume after vaporization: about 11 ml), sealing with a plastic cap was performed.

[0026]

Example 2 0.11 g of liquid nitrogen (volume after vaporization W = about 100 ml) was dropped (W / S = 5) to the head space S = 20 ml, and the remaining amount of liquid nitrogen V = 3 / 4
(The volume was about 75 ml after vaporization). The sealing was carried out under the same conditions as in Example 1 except that sealing with a plastic cap was performed.

[0027]

Comparative Example 1 Liquid nitrogen was dropped so that W / S <2.
The operation was performed under the same conditions as in Example 1 except that sealing with a plastic cap was performed when the remaining amount of liquid nitrogen was less than 1/4.

[0028]

Comparative Example 2 Liquid nitrogen was dropped so that W / S> 5, and sealing was performed with a plastic cap when the remaining amount of liquid nitrogen exceeded 3/4. Performed under the same conditions.

Table 1 below shows the evaluation results of the state of the eyes, the state of deformation due to reduced pressure, and the gas exchange rate in the polyester bottles of Examples 1 and 2 and Comparative Examples 1 and 2.

[Table 1]

[0030]

According to the present invention, as can be seen from Table 1, the state of the line of sight after filling the contents of the synthetic resin bottle is improved, and the visual anxiety of the customer and the decrease in the willingness to purchase are prevented.

Further, according to the present invention, the deformation at the time of decompression is prevented, the gas exchange of the head space after sealing is promoted, and the shelf life can be greatly extended.

Further, according to the present invention, the buckling resistance after filling the contents is greatly improved, the number of stacks can be increased, the impact resistance during transportation is improved, and the crushing of the synthetic resin bottle is prevented. In addition, distribution costs can be reduced.

[Brief description of the drawings]

Fig. 1 Reference diagram of polyester bottle

FIG. 2 is a bottom view of FIG. 1;

FIG. 3 Reference drawing of polyester bottle

FIG. 4 is a bottom view of FIG. 3;

FIG. 5 Reference drawing of polyester bottle

FIG. 6 is a bottom view of FIG. 5;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Polyester bottle 2 Body 3 Bottom 4 Leg 5 Dome 6 Reinforcement convex rib

Claims (2)

[Claims] After filling the contents of a synthetic resin bottle, the headspace is filled with liquid nitrogen having a volume at the time of vaporization which is twice to five times the headspace volume. A method for filling and sealing the contents in a synthetic resin bottle, wherein the sealing is performed when the remaining amount of liquid nitrogen in the inside becomes 1/4 to 3/4. 2. The method for filling and sealing contents of a synthetic resin bottle according to claim 1, wherein the liquid resin is filled with liquid nitrogen and the mouth of the synthetic resin bottle is blown with nitrogen gas.