JP2002104452A - Container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a container whose cap can be easily opened. SOLUTION: In such a PET bottle 1 that an inner ring 7 is in pressure contact with an inner peripheral surface 3a of a mouth 3 when a cap 5 with the inner ring 7 is screwed with the mouth 3 and fastened, a pressure contact region R where the inner ring 7 is in pressure contact with the inner peripheral surface 3a of the mouth 3 is smoother than other regions.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a container for holding a liquid, such as a plastic bottle.

[0002]

2. Description of the Related Art Generally, a cap such as a plastic bottle is attached to a mouth thereof by screwing. In such containers, there is a cap provided with an inner ring that is inserted into the inner periphery of the mouth of the container, and when the cap is tightened, the inner ring presses against the inner peripheral surface of the mouth, Enhances the tightness of the container.

On the other hand, as disclosed in Japanese Patent Application Laid-Open No. H10-72047, a cap having a contour different from that of the cap body is attached to the cap body of the container so that the cap can be easily handled with a finger, thereby turning the cap. There are things that make it easier.

Japanese Patent Application Laid-Open No. H11-165722 discloses that in order to shorten the sterilization of the inner and outer surfaces of the main body of the container in a short time, the surface roughness of at least one of the inner and outer surfaces of the main body of the container is 10 μm or less. Is disclosed.

[0005]

However, in the techniques disclosed in the above-mentioned publications, the cap is provided with an inner ring to improve the airtightness. However, when the cap is tightened, the inner ring is closed inside the mouth. By pressing the peripheral surface, the coefficient of static friction between the inner ring and the inner peripheral surface of the mouth is large, so unless a large force is applied to the cap when opening the container, the cap does not start turning, making it difficult to open the cap. There is a risk of becoming.

Accordingly, an object of the present invention is to provide a container in which a cap can be easily opened while maintaining high hermeticity.

[0007]

According to a first aspect of the present invention, there is provided a container wherein the inner ring presses the inner peripheral surface of the mouth when the cap with the inner ring is screwed into the mouth and tightened. A pressure contact area of the inner peripheral surface of the mouth where the inner ring presses is smoother than other areas.

According to the first aspect of the present invention, when the cap is tightened, the inner ring is pressed against the inner peripheral surface of the mouth to improve the hermeticity of the container. On the other hand, at the time of opening the container, by reducing the inner ring surface of the mouth to a pressure-contact area where the inner ring is pressed more smoothly than other areas, the static friction coefficient between the inner ring and the pressure-contact area of the mouth is reduced. I have. Therefore, the torque required for opening (opening of the cap) can be reduced, and the cap can be easily opened.

According to a second aspect of the present invention, in the first aspect of the present invention, the maximum value of the surface roughness of the press contact area is set to 13 μm.
It is characterized by being less than.

[0010] According to the second aspect of the present invention, the first aspect is provided.
In addition to having the same effect as the invention described in the above, the surface roughness of the press contact portion is less than 13 μm, by sufficiently reducing the static friction coefficient between the inner ring and the press contact region,
The cap can be easily opened.

[0011] The invention described in claim 3 is the invention according to claim 1 or 2.
In the invention described in the above item, the maximum value of the surface roughness of the pressure contact region is 5
μm or less.

According to the third aspect of the present invention, the first aspect is provided.
Or the same effect as that of the invention described in 2 above, and by setting the surface roughness of the press contact region to 5 μm or less,
The coefficient of static friction between the inner ring and the pressure contact area of the mouth can be further reduced, and in particular, it becomes easy to open the cap even in a small container that is hard to apply force.

The invention described in claim 4 is the first to third aspects of the present invention.
In the invention described in any one of the above, when the cap is screwed into the mouth and tightened, the cap includes a contact ring that presses the top surface of the mouth, and a press contact area of the top surface of the mouth where the contact ring presses. Is characterized in that a groove is formed in the circumferential direction of the mouth.

According to the fourth aspect of the present invention, the first aspect is provided.
In addition to providing the same function and effect as the invention described in any one of (1) to (3), by forming a groove in the pressure contact region on the top surface of the mouth, the contact ring of the cap and the top of the mouth when the cap is tightened. The contact area with the surface is reduced. Therefore, since the coefficient of static friction between the contact ring and the top surface of the mouth becomes smaller, the cap starts to rotate with a smaller force than when no groove is formed, and the groove formed in the circumferential direction is formed by the groove of the cap. As we guide rotation,
Opening the cap becomes easier.

According to a fifth aspect of the present invention, in the fourth aspect of the present invention, the cap includes an outer ring that presses the upper end of the outer peripheral surface when the cap is screwed into the mouth and fastened. Features.

According to the fifth aspect of the present invention, in the fourth aspect,
The cap can be easily opened when the inner ring, the contact ring, and the outer ring further press the mouth portion to further enhance the sealing performance, in addition to the same operation and effect as the invention described in (1).

[0017]

Embodiments of the present invention will be described below in detail with reference to FIGS. FIG.
As shown in FIG. 1, a plastic bottle (container) 1 according to the present embodiment includes a cap 5 screwed into the mouth 3.
In this embodiment, the plastic bottle 1 is 500
It is a plastic bottle for milliliter.

The cap 5 has a screw portion 5a which is screwed into the outer peripheral portion 3d of the mouth portion 3 on the inner side, and the screw portion 5a inside the cap 5 and the outer peripheral portion 3d of the mouth portion 3 are screwed together. Thereby, it can be fastened to the mouth portion 3. The cap 5 has an inner ring 7 inserted inside the mouth 3, and when the cap 5 is screwed into the mouth 3 and tightened,
When the inner ring 7 of the cap 5 is elastically deformed,
Is pressed against the inner peripheral surface 3a.

The cap 5 has a top surface 3c of the mouth portion 3.
Outer ring 9 pressing outer peripheral edge 3b of
The inner ring 7, the outer ring 9 and the contact ring 11 press the mouth portion 3 by elastic deformation, respectively, so that the tightness of the PET bottle 1 is improved. Is being improved.

In the present embodiment, the opening 3 is manufactured by molding using a mold. After the opening 3 is formed by the mold, the inner peripheral surface 3a of the opening 3 is polished. . That is, by polishing the inner peripheral side pressure contact region R of the inner peripheral surface 3a of the mouth portion 3 against which the inner ring 7 is pressed, the inner peripheral side pressure contact region R is smoother than other regions of the mouth portion 3, The coefficient of static friction between the inner peripheral side pressure contact region R and the inner ring 7 is reduced. In the present embodiment, the maximum value of the surface roughness of the press contact region R is set to 0.45 μm.

Also, as shown in FIG.
The groove 13 is formed in the top surface side pressure contact region S where the contact ring 11 is pressed against the groove c in the circumferential direction of the mouth 3. In the present embodiment, the groove 13 is formed in the die 3 that has been die-cut by forming a lathe in a die for forming the die 3. The formation of the groove 13 reduces the contact area between the contact ring 11 and the top surface side pressure contact region S, and reduces the coefficient of static friction between the contact ring 11 and the top surface side pressure contact region S. Further, the groove 13 is formed in the mouth 3
The cap 5 is guided in the groove 13 when the cap 5 starts to rotate, so that the cap 5 becomes easy to rotate.

Next, the operation of the present embodiment will be described based on the above configuration. As shown in FIG. 3A, when the cap 5 is fastened to the opening 3, the inner ring 7, the contact ring 11, and the outer ring 9 are respectively connected to the inner peripheral side pressure contact region R of the opening 3 and the top. Surface side pressure contact area S
And the outer peripheral edge 3b of the top surface 3c are pressed against each other.
The tightness inside the plastic bottle 1 is enhanced.

On the other hand, when the PET bottle 1 is opened,
When the cap 5 is turned, the contact ring 11 and the groove 13 are separated as shown in FIG. 3B, and when the cap 5 is further turned in this state, as shown in FIG. The inner ring 7 moves away from the mouth 3. The groove 13 in this case is an example of a groove formed by a lathe in a die working for forming the mouth portion 3.

When the cap 5 fastened to the opening 3 is turned, the static friction force between the inner ring 7 and the inner peripheral pressure contact area R, the static friction force between the contact ring 11 and the top pressure contact area S, and the outer friction force Ring 9 and outer peripheral edge 3 of top surface 3c
It is necessary to rotate the cap 5 with a force larger than the static friction force with the cap b. In the case of a plastic bottle 1 for 500 ml, the diameter of the body is small, so that the cap 5
The power to turn is difficult.

However, in the present embodiment, the coefficient of static friction between the inner ring 7 and the pressure contact region R and the coefficient of static friction between the contact ring 11 and the pressure contact region S are reduced, and the groove 13 is , The opening torque required for opening the cap 5 can be reduced, and the cap 5 starts to rotate without applying a large force to the cap 5, so that the cap 5 can be easily opened. it can.

Here, the maximum value of the surface roughness (R
max) and the rotational force (opening torque) required for the cap to start rotating are measured, and are shown in Table 1 below. In addition, the surface roughness of the inner peripheral surface 3a of the mouth part 3 was measured using a surface roughness measuring device "Surftest" (Miyoto Seisakusho Co., Ltd.).

[0027]

[Table 1]

In Table 1, the maximum value of the surface roughness when no polishing was performed was 13.0 μm, and the opening torque at this time was 171.1 N · cm. On the other hand, the opening torque when polishing is performed and the maximum value of the surface roughness is set to 0.45 μm is 141.4 N · cm, and the opening torque when the maximum value of the surface roughness is set to 0.5 μm. Plug torque is 1
It was 50.2 N · cm, and the cap 5 started to rotate with a small opening torque as compared with the case where polishing was not performed, and the cap 5 was easily opened.

The present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the gist of the present invention. For example, in the present embodiment, the inner ring 7 is integrally formed with the cap 5, but the present invention is not limited to this, and the inner ring 7 may be separately attached to the cap 5.

Groove 13 formed on top surface 3c of mouth 3
May be grooves continuous in the circumferential direction of the mouth 3 or may be grooves formed intermittently. Further, the grooves may be formed radially.

On the inner peripheral surface 3a of the mouth portion 3, the region to be smoothed is not limited to the inner peripheral side pressure contact region R. For example, a region R0 above the inner peripheral side pressure contact region R (see FIG. 3 (c)). ) May be smoothed, or the entire inner peripheral surface 3a may be smoothed. In addition, a region where the outer ring 9 is pressed against may be polished to smooth this region.

In the present embodiment, the cap 5 having the inner ring 7, the contact ring 11, and the outer ring 9 is used. However, when applied to at least the cap 5 having the inner ring 7, a similar effect can be obtained.

Although the present invention has been applied to the plastic bottle 1 for 500 ml, it may be applied to a large plastic bottle for 2 liters or a small plastic bottle for 500 ml or less.

In the present embodiment, the plastic bottle 1 is used as a container, but the present invention is not limited to this. For example, another resin container or a container such as a bottle may be used.

[0035]

According to the first aspect of the present invention, when the cap is tightened, the inner ring presses against the inner peripheral surface of the mouth, so that the tightness of the container can be improved. Also, by making the pressure contact area of the mouth smoother than other areas, the coefficient of static friction between the inner ring and the pressure contact area of the mouth is reduced, so that the torque required for opening the cap can be reduced, The cap can be easily opened.

According to the second aspect of the invention, the same operation and effect as those of the first aspect of the invention are obtained, and the surface roughness of the press-contact portion is set to less than 13 μm to sufficiently reduce the static friction coefficient. The cap can be easily opened.

According to the third aspect of the invention, the same operation and effect as those of the first or second aspect of the invention are provided, and the surface roughness of the press contact area is set to 5 μm or less, so that the inner ring and the opening can be formed. The coefficient of static friction with the press-contact area can be further reduced, and in particular, it becomes easy to open the cap even for a small container that is difficult to apply force.

According to the fourth aspect of the invention, the same effects as those of the first to third aspects of the invention can be obtained, and the contact ring and the top surface of the mouth can be formed by forming the groove. The contact area is reduced, the coefficient of static friction between the contact ring and the top surface of the mouth is reduced, and the groove formed in the circumferential direction guides the rotation of the cap. It will be easier.

According to the fifth aspect of the invention, the same operation and effect as those of the fourth aspect of the invention are provided, and the inner ring, the contact ring, and the outer ring press the mouth, and the cap is closed. The cap can be easily opened even if the cap is firmly tightened.

[Brief description of the drawings]

FIG. 1 is a front view showing a cross section of a part of a mouth portion of a plastic bottle to which the present invention is applied.

FIG. 2 is an enlarged sectional view showing the vicinity of a top surface of a mouth and a contact ring of a cap.

3A and 3B are diagrams illustrating a state in which a cap is attached to a mouth, wherein FIG. 3A illustrates a state in which the cap is fastened to the mouth, and FIG. 3B illustrates a state in which the cap starts to rotate;
(C) shows a state where the inner ring of the cap is separated from the mouth.

[Explanation of symbols]

 Reference Signs List 1 PET bottle (container) 3 mouth 3a inner peripheral surface of mouth 3b outer peripheral edge of top surface 3c top surface of mouth 5 cap 7 inner ring 9 outer ring 11 contact ring 13 groove R inner peripheral side pressure contact area S Top side pressure welding area

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3E084 AA04 AA12 AA24 AB01 BA01 CA01 CC03 DA01 DB12 DC03 FA09 FB01 GA04 GB04 HA03 HB02 HC03 HD01 HD03 HD04

Claims (5)

[Claims] When a cap with an inner ring is screwed into a mouth and tightened, the inner ring of the inner ring of the mouth comes into pressure contact with the inner ring of the container when the inner ring presses the inner peripheral surface of the mouth. A container wherein the pressure contact area is smoother than other areas. 2. The container according to claim 1, wherein the maximum value of the surface roughness of the press-contact area is less than 13 μm. 3. The container according to claim 1, wherein the maximum value of the surface roughness of the press contact area is set to 5 μm or less. 4. The cap has a contact ring that presses against the top surface of the mouth when screwed into the mouth and tightens. The container according to any one of claims 1 to 3, wherein a groove is formed in a circumferential direction of the portion. 5. The container according to claim 4, wherein the cap includes an outer ring that presses the outer peripheral edge of the top surface when screwed into the mouth and fastened.