JPS6333268A - Liner for roll-on type cap - Google Patents

Abstract

(57) [Abstract] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a liner for a roll-on cap used in containers for holding soft drinks, water, alcoholic beverages, and other liquids, especially containers subject to internal pressure such as carbonated drinks. be.

[Conventional technology]

A roll-on cap consists of a metal cap shell,
The cap is composed of a flexible liner provided on the lower surface of the top surface of the cap shell.

The metal cap shell has a circular top wall, a deformable shoulder that hangs down from the periphery of the top wall, and a skirt that can be deformed along the thread of the container opening to be covered.

A method of sealing this roll-on cap to a container, especially a container containing an object subject to internal pressure such as carbonated beverages, is to deform the shoulder of the cap using a roll-on seamer having a head pressure block with an inner diameter smaller than the outer diameter of the cap.
This pressed the liner against the upper and outer surfaces of the container mouth.

Conventionally, liners for roll-on caps have been those in which a disc of paper, polyolefin, or synthetic resin such as EVA is adhered to the top surface of the cap shell, or those in which polyvinyl chloride sol is poured.

However, the disc type liner had the disadvantage of poor productivity and high cost.

On the other hand, a cast liner (spin liner) has a high 4L productivity because it pours polyvinyl chloride sol into a cap shell and heats it to gel. However, it tends to cause uneven pouring, and as a result, the liner's However, there was a drawback in that the unevenness in thickness caused poor sealing.

Therefore, a liner shape that does not have these drawbacks was developed based on the spin liner set.

As shown in FIGS. 8 and 9, there are various shapes, but all of them have a high degree of sealing performance considering the internal pressure of carbonated drinks and the like. In all of these, in order to obtain high sealing performance, the inner wall (15) of the annular protrusion (11) that contacts the outer surface of the container opening (3) was formed vertically.

[Problem that the invention seeks to solve]

For caps, especially those used for containers containing contents with internal pressure, the following requirements are required for the shape of the liner.

■ Good adhesion to the container to achieve high sealing performance.

■ The internal pressure can be released quickly when opening the package.

■ When the camp is placed on the space between the containers, it can be easily pressed into the specified position using the roll-on seamer.

However, the developed inner shape (FIGS. 8 and 9) was still unsatisfactory in terms of ■ and ■.

That is, since the inner wall (15) of the annular protrusion (11) is vertical, the annular protrusion (11) is bent inward by the deformed cap shoulder (16) during sealing, as shown in FIG. is pressed into the container more than necessary. In Fig. 10, the annular protrusion (11) marked with a solid line indicates the extent to which it would deform if there was no container, and the annular protrusion (11) marked with a two-dot chain line indicates the state in which it would be in close contact with the container. It shows.

As a result of being strongly pressed in this way, an annular protrusion (11
) to the container opening (3) becomes greater than the necessary 1, and after opening and closing the container, the inner wall (
The air inside the container will not be released until the container (15) is completely contacted with the outer surface (25) of the container. Therefore, as soon as the cap is opened, pressure is released all at once, and there is a risk that the cap will be blown off (blow-off).

In addition, since the liner shape shown in Figure 8 has a large annular protrusion (26) on the inside, the cap (2) placed on the container opening (3) is in an extremely unstable position and may be camped in an inclined position. In some cases, this caused capping failure.

Therefore, an object of the present invention is to prevent blow-off and enable stable capping while maintaining high sealing properties of the liner shape.

[Means for solving problems]

In this invention, the outer diameter of the head pressure block (14
), an annular protrusion (11) is formed on the outer periphery, and the inner wall (15) of the annular protrusion (11)
3) It is sloped so that it goes downward from the outer diameter and the diameter of the gap, etc., so that it widens toward the end.

[Effect]

1) This invention makes the outer diameter of the liner larger than the inner diameter of the head pressure block (14), and the inner wall (
15), even at the root of the inner wall, which is the smallest, is set between the outer diameter of the container opening (3) and the passage.

Therefore, when the cap is placed on the container opening (3), the annular protrusion (11) always covers the outer surface of the container opening (3) (
Figure 6 right). In this state, when the head pressure block (14) is lowered as shown on the left side of FIG. 6, the cap shoulder portion is deformed. Pressed by the deformed cap shoulder, the liner, which is larger than the inner diameter of the head pressure block (14), is pushed downward and tightly contacts the outer surface of the container opening (3). Therefore, it is possible to secure sufficient contact pressure and contact area to obtain a high degree of sealing performance.

2) In this invention, the inner wall (15) of the annular protrusion (11) is inclined so as to widen toward the bottom.
As shown in the figure, it is possible to prevent the annular protrusion (11) from being excessively pressed against the container in the case of closeness 1.1. Therefore, the adhesion pressure can be controlled, and blow-off can be prevented by gradually releasing pressurized air immediately after opening the package.

Moreover, the slope of the inner wall (15) widening toward the end is adjusted to a predetermined posture (
It is possible to easily guide the user to a posture in which the central axes of the cap and the container are the same, allowing camping while maintaining a normal posture.

〔Example〕

Embodiments of the invention will be described based on the drawings.

Figures 1 and 2 show a camp (2) and a container opening (3) using the liner (1) of the present invention.

In FIG. 1, the cap (2) is composed of a metal cap shell (4) and a liner (1), and has a circular top surface (5) and a periphery of the top surface (5). It consists of a skirt (6) that hangs down from the top. Liner (1)
Thermoplastic resin was dripped onto the lower surface of the kl top surface (5) and molded into a -leg shape. The inter-container part (3) forms a side sealing part (7) and a thread (8) in order from the top.

Figure 2 shows a cap (
2) and the container opening (3), and the cap (
2) is the same as in Figure 1 except that it has a pilfer-proof band (9) and the container opening (3) has a flange (10) for wrapping the pilfer-proof hand (9).

As shown in FIG. 3, the liner shape of the present invention has an annular protrusion (11) on the outermost periphery and a thick pressure welding part (12) on the inner side.
) is formed into an annular shape, and the thinnest center panel portion (13) is formed in the center.

The characteristics of the shape of the liner of this invention are as shown in FIG.
The inner diameter of the hesodopressure socket (14) (not shown) should be larger; ■ The minimum diameter of the base of the inner wall (15) of the annular protrusion (11) should be set at the container opening. (
3) between the outer diameter DB and the track, etc., and the inner wall (15) is formed in a shape that opens in the 4ζ direction, with the inner wall (15) being inclined to widen toward the bottom.

Ideally, it is desirable for Dl to be equal to I], but in reality, processing errors are taken into account during container manufacturing, so the range shown by the inequality below is appropriate.

Dll-d≦D1≦DB→-d In the formula, d is the maximum machining error of the diameter of the container opening (3), which generally takes a value in the range of 0.3 to 0.5 mm.
The inclination angle α of 15) is in the range of 5 to 45°. The reason for limiting this range is as follows. 6th M
As shown on the left, the inner wall (15) of the henodopressor press (14) that descends during capping deforms the camp shoulder (16), and this deformed camp shoulder (16) causes the liner ( The annular protrusion (1) of 1) is pressed against the side sealing part (7) of the container opening (3) and is pushed to the front surface thereof. In this way, a high degree of sealing performance is obtained, but if the inclination angle α exceeds 45°, the lower end of the annular protrusion (11) becomes too wide, making it impossible to obtain sufficient sealing pressure and sealing area. Furthermore, if the inclination angle α is smaller than 5°, the annular protrusion (11) will be subjected to excessive pressing force, which may cause stress cranking.

The height of the annular protrusion (11) is in the range of 0.5 to 1.5 mm.

The reason why the upper limit is set to 1.5 mm is because if this value is exceeded, the release of pressure air upon opening will be delayed and the gas will blow out all at once, leading to the risk of blow-off. The reason why the lower limit is set to 0°5 mm is because if it is lower than this, a gap may occur, and although there is some tightness, the sealing pressure becomes weak and sealing becomes impossible or insufficient.

In particular, with a pilfer-proof cap, if the sealing is insufficient, the internal pressure of carbonic acid, etc. will be released by a slight rotation of the cap, and the product will not be able to handle the product even though the pilfer-proof band (9) is not broken. This will cause deterioration and the pilfer-proof properties will not function effectively.

In addition to the above-mentioned features, the liner of this invention can have a shape as shown in FIG. 3.

Container opening (3) An R section (
By forming 17), it is possible to prevent thalassociation caused by stress concentration occurring at this corner after capping, and to ensure close contact with the container opening (3) [-1-].

Furthermore, a small annular protrusion (1B) can be formed on the inner peripheral side of the thick pressure welding part (12) in one step to facilitate the embossing process of the liner.

Further, in order to reinforce the top surface (5) of the cap (2) and improve workability, radial ribs (20) can be formed with a very slight wall thickness (19).

Next, cap (2) consisting of the above structure is installed. Soping # method will be explained.

Capping is done by lowering the heel pressure prosock (14) and lowering the cap shoulder (]6) as shown in Figure 6.
At the same time, the cap (2) is sealed by the RO roller (21) by deforming the liner (1) to seal the container.
[Effects of the Invention] This invention makes the outer diameter of the liner larger than the inner diameter of the hesodopressure protector (14), and also tightens the liner to the inner wall (15).
) has the smallest diameter, it is at least spaced between the outer diameter of the container opening (3) and the channel, so a high degree of sealing performance can be obtained. (15) is inclined to widen toward the bottom, making it possible to prevent blow-off and to perform capping in a stable position.

[Brief explanation of drawings]

1 to 6 are drawings showing one embodiment of the present invention. FIG. 1 is a front view of a cap and a container opening that fits into the cap. FIG. 2 is a front view of the pilfer-proof cap and the container opening that fits into it. FIG. 3 is an enlarged sectional view of the liner. FIG. 4 is a sectional view taken along the line AA in FIG. 3. FIG. 5 is a sectional view showing the relationship between the diameters of the hesod pressure prosock, the liner, and the opening of the container. In FIG. 6, the right side is a cross-sectional view showing the state in which the cap is placed on the opening of the container, and the left side is a cross-sectional view showing capping with a head pressure sosher. FIG. 7 is a sectional view showing the degree of deformation of the annular protrusion. FIGS. 8 to 10 are drawings showing the prior art. 8th
The figure is a sectional view showing a liner with two annular protrusions on the outside and the outside. FIG. 9 is a sectional view showing a liner with one annular protrusion on the outside. FIG. 10 is a sectional view showing the degree of deformation of the annular protrusion of the liner shown in FIG. 9. (1)...Liner (2)...Cap (3)
)... Container opening (11)... Annular protrusion (12)
... Thick pressure welding part (13) ... Center panel part (
14)... Hesodo Pressure Prosoku (15)...
・Inner q (16)...Cap shoulder Do・
... Liner outer diameter, ... Minimum diameter DH of the inner wall of the annular protrusion, ... Head pressurization inner diameter α ...
Inclination angle of inner wall

Claims (1)

[Claims] 1. In a liner for a roll-on cap capped by a roll-on seamer having a head pressure block (14) with an inner diameter smaller than the outer diameter of the cap, the outer diameter is larger than the inner diameter of the head pressure block (14), and an annular protrusion ( 11), and the inner wall (15) of the annular protrusion (11) is inclined from a diameter approximately equal to the outer diameter of the container opening (3) to become wider toward the bottom. Roll-on cap liner.