JP3024403B2 - Manufacturing method of internal pressurized container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of manufacturing an internal pressurized container, and more particularly to a method of manufacturing an internal pressurized container suitable for storing powder.

[0002]

2. Description of the Related Art Conventionally, there has been known a technique of filling contents such as beverages into a thin cylindrical can (container) made of an aluminum alloy or steel. In such cans, after filling the contents into the can body, the can body (container body)
A liquefied gas (for example, liquid nitrogen) is dropped into the inside of the container, and then a can lid (lid) is attached to seal the inside. According to this technique, the internal pressure of the can can be increased, and the strength of the can can be improved. Such technology is disclosed in JP-B-63-667.
As shown in Japanese Patent Publication No. 36, it is already well known.

By the way, attempts have been made to fill the above-mentioned thin cans with powder such as ground coffee beans. When powder is stored in such cans, the amount of materials used for can production and material costs can be reduced,
In addition, there are various advantages such as a reduction in the weight of the can and a reduction in transportation cost.

However, when a liquefied gas is injected into a powder in the same manner as in the prior art, when the injected liquefied gas comes into contact with the powder, the liquefied gas is instantaneously finely broken and vaporized immediately. The reason that the liquefied gas breaks is presumed to be that the contact area between the powder and the liquefied gas is large because the surface area of the powder itself is large. The reason that the crushed liquefied gas is immediately vaporized is that the surface area of the liquefied gas itself is significantly increased. As described above, when the liquefied gas is immediately vaporized, even if the lid is attached after the dropwise addition of the liquefied gas, the internal pressure cannot be sufficiently increased,
Therefore, there is a problem that it is difficult to ensure the strength of the can.

[0005]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has an internal pressurized container capable of sufficiently increasing the internal pressure even when the inside is filled with powder. The purpose of the present invention is to provide a manufacturing method.

[0006]

According to a first aspect of the present invention, there is provided a method of manufacturing an internal pressurized container, comprising: filling a powder into a bottomed cylindrical container body having an open upper surface; The portion is covered with a covering member, a liquefied gas is injected into the top surface of the covering member, and then a lid is attached to the top surface of the container body to seal the inside.

According to a second aspect of the present invention, there is provided a method of manufacturing an internal pressurized container, comprising the steps of:
It has a mortar shape.

According to a third aspect of the present invention, there is provided a method of manufacturing an internal pressurized container according to the first or second aspect, wherein a handle is attached to an upper surface or a side surface of the covering member.

[0009]

When the liquefied gas is injected into the upper surface of the covering member, compared to when the liquefied gas is directly injected into the upper surface of the powder,
The contact area between the liquefied gas and other substances is small. For this reason,
The injected liquefied gas does not immediately break and evaporate, and can remain in a liquid state for a while on the upper surface of the covering member. By attaching the lid to the container body in this state, the internal pressure of the container can be increased.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A method for manufacturing an internal pressurized container according to one embodiment of the present invention will be described with reference to FIG. First, each member shown in FIG. 1 will be described. Reference numeral 10 in the figure denotes a thin can body (container main body) made of an aluminum alloy and formed in a bottomed cylindrical shape. The entire upper surface of the can body 10 is open, and this portion forms an opening 11. This opening 1
The lower part of the neck 1 has a neck 1 narrowed upward.
2 are formed. A can lid (lid ... not shown ...) is attached to the opening 11 by tightening, so that the inside of the can is sealed. In this example, a known full-open can lid having a cut line formed along the outer periphery of the can lid is used as the can lid.

Inside the can body 10, powder 2 for regular coffee extraction obtained by grinding coffee beans with a mill or the like is used.
0 is stored. On the upper surface of the powder 20, a sheet (coating member) made of synthetic resin such as vinyl chloride or polyethylene
30 are placed. The shape of the sheet 30 is
Has a diameter slightly smaller than the inner diameter of the opening 11. The thickness of the sheet 30 is from 0.01 mm
It is configured to be about 0.5 mm.

Next, the manufacturing method of this embodiment will be described. First, the powder 20 is stored inside the can body 10. At this time, the position of the upper end of the powder 20 is slightly lower than the open end of the can body 10. Next, the sheet 30 is placed substantially at the center of the upper surface of the powder 20, and the upper surface of the powder 20 is covered with the sheet 30. In this state, liquid nitrogen 1 (two-dot chain line in FIG. 1) is dropped on the upper surface of the sheet 30. Then, since the liquid nitrogen 1 is in contact only with the sheet 30, the powder 20
As compared with the case where the substrate is brought into direct contact, the time required for vaporization is longer, and the liquid remains for a while for a while. In this state, the can lid is placed on the opening 11 of the can body 10, the outer periphery of the can lid is tightened, and the can lid is fixed to the opening 11 of the can body 10.
The inside of the can can be sealed.

When liquid nitrogen is dropped directly on the upper surface of the powder 20, there is a disadvantage that the internal pressure of the can becomes insufficient because the liquid nitrogen is immediately vaporized. For example, there is an advantage that the internal pressure of the can can be increased as compared with such a method.

In the case of using a sealed can in this manner, after opening the can lid by a usual method, the sheet 3
0 can be removed and the powder 20 can be used as usual.

Next, a method for manufacturing an internal pressurized container according to a modification of the present invention will be described with reference to FIG. The method of this modified example is different from the above-described embodiment in that a sheet 130 formed in a mortar shape with a concave center is used as a covering member. The sheet 130 has a substantially circular shape in a plan view, and the thickness thereof is
Is the same as In the method of this modification, the sheet 130 is placed on the upper surface of the powder 20 such that the upper surface of the sheet 130 has a substantially mortar shape.

According to the method of the modified example, since the liquid nitrogen 1 dropped on the upper surface of the sheet 130 is collected at the recessed central portion, the contact area between the liquid nitrogen and the sheet 130 is small. Therefore, as compared with the method of the above embodiment, there is an advantage that the time until the liquid nitrogen 1 evaporates can be extended, and the internal pressure of the can can be further increased. Other configurations and operations of this modified example are the same as those of the above-described embodiment, and thus detailed description will be omitted.

Next, a method for manufacturing an internal pressurized container according to another modification of the present invention will be described with reference to FIG.
The method of this example differs from the method of the above embodiment in that a circular plate 230 having a thickness of about 1 to 3 mm is used as a covering member. As a material of the plate 230, for example, a thermoplastic, relatively hard synthetic resin can be used. The plate 230 is formed in a circular shape smaller than the opening of the can lid, and can be taken out from this opening. A handle 231 projecting upward is attached to the upper surface of the plate 230. The height of the handle 231 is set to a height that does not interfere with the can lid attached to the opening of the can body 10.

According to the method of this embodiment, since the plate 230 having a predetermined thickness is used,
The handle 231 can be attached to the zero.

Therefore, in the method of this embodiment, the handle 23
Since the plate 230 can be removed from the upper surface of the powder 20 by pinching the plate 1, there is an advantage that the plate 230 can be easily removed when using the can. Other configurations and operations of this modified example are the same as those of the above-described embodiment, and thus detailed description will be omitted.

In each of the above-described methods, a method in which coffee beans are pulverized has been described as an example of the powder, but the point is that the method of the present invention is effective as long as it is in powder form.

In each of the above examples, liquid nitrogen is used as the liquefied gas. However, it is obvious that other types of liquefied gas can be used.

Further, in each of the above examples, the thin can body 10 is used as the container body, but the method of the present invention can be applied to, for example, a container made of a synthetic resin. In short, any internal pressurized container for storing the powder may be used.

Further, in each of the above-described examples, the example in which the liquefied gas is injected into the inside of the can body by dripping is shown. However, the present invention is not limited to this. May be injected.

Further, in this embodiment, the covering member is formed in a circular shape, but this shape is adapted to the shape of the opening of the can lid.
What is necessary is just to make it easy to take out.

[0025]

According to a first aspect of the present invention, there is provided a method of manufacturing an internal pressurized container, comprising: filling a powder in a bottomed cylindrical container body having an open upper surface; Liquefied gas is injected into the upper surface of the coating member, and then the lid is attached to the upper surface of the container body to seal the inside, so that the internal pressure of the container can be increased and its strength can be increased. Can be improved.

According to a second aspect of the present invention, there is provided a method of manufacturing an internal pressurized container, comprising the steps of:
Since it is formed in a mortar shape, the internal pressure of the container can be further increased.

According to a third aspect of the present invention, in the method of the first or second aspect, the handle is attached to the upper surface or the side surface of the covering member. After that, the covering member can be easily removed.

[Brief description of the drawings]

FIG. 1 is a sectional view of a can body used in a method for manufacturing an internal pressurized container according to one embodiment of the present invention.

FIG. 2 is a sectional view of a main part of a can body used in a method of manufacturing an internal pressurized container according to a modification of the embodiment.

FIG. 3 is a sectional view of a main part of a can body used in a method of manufacturing an internal pressurized container according to another modification of the embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Liquid nitrogen (liquefied gas) 10 Can body (container main body) 11 Opening formed in the upper surface of container main body 20 Powder 30/130 Sheet (covering member) 230 Plate (covering member) 231 Handle

Claims (3)

(57) [Claims] After filling a powder into a bottomed cylindrical container body having an open upper surface, at least a part of the upper surface of the powder is covered with a covering member, and a liquefied gas is applied to the upper surface of the covering member. A method of manufacturing an internal pressurized container, which comprises injecting, and then sealing the inside by attaching a lid to the upper surface of the container body. 2. The method according to claim 1, wherein an upper surface of the covering member is formed in a mortar shape. 3. The method according to claim 1, wherein a handle is attached to an upper surface or a side surface of the covering member.