JP4727162B2 - Container lid with internal pressure release characteristics - Google Patents

Description

  The present invention relates to a container lid having an internal pressure release characteristic, and more particularly to a container lid that can be locally deformed and automatically opened when the container internal pressure rises excessively.

  As disclosed in the following Patent Document 1, as a container lid for a container containing a fruit juice containing natural fruit juice or a carbonated drink, a container lid having a metal thin plate lid body is widely used in practical use. Yes. The lid body has a circular top wall and a cylindrical skirt wall depending from the top wall. Usually, a synthetic resin liner is disposed on the inner surface of the top wall. A concave / convex shape portion in which a concave portion and a convex portion are alternately repeated is formed on the upper portion of the skirt wall of the lid main body. In addition, the skirt wall usually has a circumferential break line extending in the circumferential direction, and the skirt wall has a main portion above the circumferential break line and a tamper evidence skirt below the circumferential break line. It is divided into and. In the tamper evidence skirt, an axial break line extending in the axial direction is usually formed.

  The container lid is applied to a metal thin plate, glass, or synthetic resin container having a cylindrical mouth and neck with an open upper surface. A male thread and a locking protrusion located below the male thread are formed on the outer peripheral surface of the mouth and neck of the container. When sealing the mouth and neck by attaching the container lid to the mouth and neck of the container, the container lid is fitted on the mouth and neck, and the mouth and neck part is located in the lower part of the uneven part in the main part of the skirt wall. The female thread corresponding to the male thread is formed, and the tamper-evidence skirt of the skirt wall is deformed radially inward to be locked to the locking protrusion on the mouth and neck.

  When opening the mouth and neck of the container, the container lid is rotated in the opening direction, the circumferential break line is partially broken and the axial break line is broken, and the tamper evidence hem is endlessly annular. And then the tamper-evidence hem is unlocked with respect to the locking projection of the mouth and neck. Further, the container lid is rotated in the opening direction to release the female thread from the male thread in the mouth and neck, and the container lid is detached from the mouth and neck. Thus, when a relatively high pressure exists in the container, the internal pressure of the container is released when the female thread of the container lid is released to some extent from the male thread of the mouth and neck. is important. Otherwise, when the female thread of the container lid with respect to the male thread of the neck of the mouth and neck is released to some extent, the container lid may accidentally fly due to the relatively high internal pressure of the container. There is a risk of damage. Therefore, a slit extending in the circumferential direction is usually formed in the concave portion of the concave-convex shape portion formed on the skirt wall, and when the screwing of the female thread of the container lid to the male thread of the mouth-neck part is released to some extent The internal pressure of the container is released through the slit.

In the container lid disclosed in Patent Document 1 below, the container lid is mounted on the mouth and neck of the container as required, or the container lid once removed from the mouth and neck of the container is re-contained. When the internal pressure of the container rises excessively due to excessive heating of the container or the contents of the container being spoiled with the mouth and neck sealed temporarily In order to avoid accidental flight of the container lid, etc., at least one slit in the concavo-convex shape portion is intended to cause the container lid to be locally deformed so that the internal pressure of the container is released. Is made longer than other normal slits.
Japanese Patent Laid-Open No. 2003-155052

  However, according to the experience of the present inventors, in the container lid disclosed in the above-mentioned Patent Document 1, the container lid is attached to the mouth and neck of the container as required, or once the mouth and neck of the container. Even if the internal pressure of the container rises excessively in the state where the container lid that has been detached from the container is attached to the mouth and neck of the container again and the mouth and neck are temporarily sealed, the container lid is not deformed sufficiently reliably. There is a problem that the internal pressure of the is not released sufficiently reliably.

  The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is that the container lid is attached to the mouth / neck portion of the container as required, or once removed from the mouth / neck portion of the container. If the internal pressure of the container rises excessively when the container lid is attached to the mouth and neck of the container again and the mouth and neck are temporarily sealed, the container lid is deformed as required and the internal pressure of the container is reliably released. And providing a new and improved container lid.

As a result of intensive studies and experiments, the inventors of the present invention have (1) a relatively long slit for generating deformation of the container lid, which has a relatively large rigidity. (2) In order to release the internal pressure of the container, it is necessary that a part of the top wall is deformed upward and the sealing of the mouth and neck is released. Due to the fact that the relatively long slit for generating the deformation of the lid is formed relatively far below the top wall, it is difficult to generate the upward deformation of the top wall. Recognized that it was not released with sufficient certainty. And based on this recognition, the above-mentioned main technical problem can be achieved by forming a slit having a required length (that is, a kerf formed by cutting a thin metal plate ) above the concavo-convex shape portion. I found out that I can do it.

That is, according to the present invention, the container lid is fitted to a container having a nominal diameter of the mouth and neck of 38 mm,
A lid body made of a thin metal plate having a top wall and a skirt wall that hangs down from the periphery of the top wall. In the container lid to be formed,
A slit extending in the circumferential direction is formed in the concave portion in the concave-convex shape portion,
The skirt wall is provided with an internal pressure releasing means that is located above the concavo-convex shape portion and that includes at least one slit extending in the circumferential direction, and the skirt wall includes the slits constituting the internal pressure releasing means. The circumferential length Ws is 7 to 14 mm.
A container lid is provided.

Good Mashiku, said slit constituting the internal pressure release means that have been brought positioned Hs below 1.0 to 3.0mm from the upper surface outer circumferential edge of the top wall.

In the container closure of the present invention, in its upper rather than the rigidity is relatively large concave and convex portion, the top panel wall of the upper surface outside the required length formed proximate peripherally situated slit DOO or et internal pressure release means is configured Therefore, the container lid is attached to the mouth / neck of the container as required, or the container lid once removed from the mouth / neck of the container is attached to the mouth / neck of the container again to If the internal pressure of the container rises excessively in a temporarily sealed state, the container lid is deformed as required, and the internal pressure of the container is reliably released.

  The container lid constructed in accordance with the present invention will now be described in more detail with reference to the accompanying drawings.

  Referring to FIG. 1, the container lid, generally indicated by numeral 2, is composed of a metal thin plate lid body 4 and a synthetic resin liner 6. The lid body 4, which is advantageously formed from an aluminum-based alloy thin plate having a thickness of about 0.22 to 0.26 mm, has a circular top wall 8 and a cylindrical skirt wall 10 depending from the periphery of the top wall 8. Have An immersion portion 11 is provided at the center of the top wall 8. A rupture line 12 extending in the circumferential direction is formed at a lower portion of the skirt wall 10, and the skirt wall 10 is formed into a main portion 14 above the break line 12 and a tamper evidence skirt portion 16 below the break line 12. It is partitioned. An annular bulging portion 18 bulged slightly outward in the radial direction is formed at the lower part of the skirt wall 10, and an appropriate interval is provided in the circumferential direction at the center in the axial direction of the annular bulging portion 18. A plurality of slits 20 extending in the circumferential direction are formed, and the breaking line 12 is defined by the plurality of slits 20 and a plurality of bridging portions 22 remaining between the slits 20.

  An annular groove 24 is formed at a substantially central portion in the axial direction of the main portion 14 of the skirt wall 10. A region below the annular groove 24 in the main portion 14 of the skirt wall 10 is a threaded portion 25 in which a female thread is formed later. The annular groove 24 is a female thread when the female thread is formed in the threaded portion 25. Used to position the strip forming tool. In the region above the annular groove 24 in the main portion 14 of the skirt wall 10, the concave and convex portions 26 and the convex portions 28 are alternately repeated so as to prevent slipping when the container lid 2 is rotated with a finger. A shape portion is formed. In the container lid 2 of the illustrated embodiment, the respective circumferential widths Wa of the recesses 26 are made substantially the same as the respective circumferential widths Wb of the projections 28. In the container lid 2 of the illustrated embodiment, a slit 30 extending in the circumferential direction is formed at the upper end of the recess 26.

The In the container closure of the present invention, the skirt wall 10, at least one slit bets or it constructed internal pressure release means 31 and extending in a circumferential direction located above is disposed than uneven portion is important. In the container lid of the illustrated embodiment, the internal pressure releasing means 31 is a single slit formed in the skirt wall 10 . Circumferential length Ws of the slit constituting the inner pressure releasing means 31 is important to be 7 to 14 mm. Preferably, the slit is positioned below Hs that is 1.0 to 3.0 mm from the outer peripheral edge of the top surface of the top wall 8. In particular, Hs is preferably 1.5 to 2.5 mm.

  The liner 6 that can be molded from an appropriate synthetic resin such as soft polyethylene is disposed on the inner surface of the top wall 8 of the lid body 4. The liner 6 can be disposed by supplying a synthetic resin material to a required position on the inner surface of the top wall 8 and embossing it into a required shape. In this case, it is preferable in terms of impact resistance that the peripheral edge of the liner 6 is in a non-bonded or weakly bonded state with respect to the inner surface of the top wall 8. If desired, a separately formed liner can be at least partially adhered to the inner surface of the top wall 8. The illustrated liner 6 includes a relatively thick annular peripheral portion 7, a relatively thin central circular portion 9, and an annular extending wall 13 extending downward from the boundary between the annular peripheral portion 7 and the central circular portion 9. Have

  FIG. 2 also shows the mouth / neck portion 32 of the container to which the container lid 2 is applied. The illustrated container is formed of an aluminum-based alloy thin plate and has a substantially cylindrical mouth-neck portion 32. The upper end portion of the mouth and neck portion 32 has a truncated cone shape that is inclined inward in the radial direction upward, and an outer curl 34 is formed at the upper end. The mouth and neck portion 32 is formed with a male thread 36 at an axially intermediate portion, and an annular locking jaw 38 bulged outward in the radial direction is formed below the male thread 36. The container lid 2 configured in accordance with the present invention is not limited to the container having the mouth-and-neck portion 32 of the illustrated form, but has a mouth-and-neck portion of another form formed from a metal thin plate, glass, or an appropriate synthetic resin. It goes without saying that it can also be applied to containers.

  The description will be continued with reference to FIG. 2 together with FIG. 1. When the container lid 2 is attached to the mouth / neck portion 32 and the mouth / neck portion 32 is sealed, the container lid 2 is fitted on the mouth / neck portion 32. The container lid 2 is pressed downward at a required pressure, and the peripheral edge of the liner 6 is brought into close contact with the curl 34 formed at the upper end of the mouth-and-neck portion 32. Then, the boundary region between the top wall 8 and the skirt wall 10 of the lid body 4 is deformed downward and radially inward to form an immersive portion 40, and the thread portion 25 in the main portion 14 of the skirt wall 10 A female thread 42 is formed so as to correspond to the male thread 36 of the neck 32, and the lower part of the tamper evidence skirt 16 is displaced radially inward to form an annular locking jaw 38 of the mouth and neck 32. Lock it. Thereafter, the container in which the mouth / neck portion 32 is sealed with the container lid 2 is subjected to appropriate processing such as retort processing (heat sterilization processing) and cleaning processing.

  When opening the mouth / neck portion 32 of the container sealed by the container lid 2, the container lid 2 is rotated in the opening direction, that is, counterclockwise as viewed from above in FIG. Thus, the female thread 42 formed on the skirt wall 10 moves along the male thread 36 formed on the mouth-and-neck portion 32, and therefore does not rise with rotation. However, since the tamper evidence skirt 16 is locked to the annular locking jaw 38, it is prevented from rising, so that considerable stress is generated at the breaking line 12, and more particularly at the bridging portion 22 thereof. The portion 22 is broken and the tamper evidence skirt 16 is separated from the main portion 14 of the skirt wall 10. Thereafter, the container lid 2 is lifted with rotation except for the tamper evidence skirt 16 and is detached from the mouth and neck portion 32, thus opening the mouth and neck portion 32. When it is desired to temporarily re-seal the mouth-and-neck portion 32 once opened, the container lid 2 that has been detached from the mouth-and-neck portion 32 is fitted again on the mouth-and-neck portion 32 and closed, that is, FIG. In this case, the female screw 42 of the container lid 2 may be rotated in the clockwise direction as viewed from above and screwed into the male screw 36 of the mouth-and-neck portion 32. When the female thread 42 is sufficiently screwed into the male thread 36, the peripheral edge of the liner 6 is brought into close contact with the curl 34 of the mouth and neck 32, and the mouth and neck 32 is sealed.

  When the content contained in the container is, for example, a fruit juice drink containing natural fruit juice, the mouth and neck part 32 is once opened as described above, and the contents are exposed to the atmosphere. When the container is sealed again, the internal pressure of the container may rise abnormally due to the fermentation phenomenon of natural fruit juice. In addition, even when the neck and neck portion 32 is once opened, if the contents contained in the container are carbonated beverages, the container internal pressure will rise abnormally if heated significantly by exposure to sunlight. There is. In the container lid 2 constructed according to the present invention, when the container internal pressure rises excessively and exceeds a predetermined value, the lid main body 4 is caused to release the internal pressure due to the excessive container internal pressure as shown in FIG. The deformation is centered on the slit 31, the sealing action by the liner 6 is locally damaged by such deformation, and the internal pressure of the container is released through the slits 30 and 31. In the container lid configured as described above, when the circumferential length Ws of the internal pressure releasing means 31 is excessively long, when the container lid 2 is attached to the mouth / neck portion 32 of the container, or the container internal pressure is reduced. Before rising excessively, for example, during the retort process (heat sterilization process), the lid body 4 is deformed around the slit that is the internal pressure releasing means 31, and the tendency that the internal pressure of the container is released, in other words, In a situation where the sealing of the mouth and neck portion 32 must be maintained, the mouth and neck portion 32 tends to be opened, and when the circumferential length Ws of the internal pressure releasing means 31 is excessively short, the container lid 2 Is attached to the mouth-and-neck portion 32 of the container as required, or the container lid 2 is once detached from the mouth-and-neck portion 32 of the container and then attached to the mouth-and-neck portion 32 of the container to temporarily attach the mouth and neck of the container. In a state where the portion 32 is sealed , Even if the internal pressure of the container is excessively increased, the internal pressure of the container without the container closure 2 is always sufficiently reliably deformed tends to not sufficiently reliably opened. Further, when the slit is not positioned sufficiently below the outer peripheral edge of the top surface of the top wall 8, when the container lid 2 is attached to the mouth / neck portion 32 of the container or before the internal pressure of the container rises excessively, for example, During the retort process (heat sterilization process), the lid body 4 tends to be deformed around the slit which is the internal pressure release means 31 and the internal pressure of the container is released. If the mouth-and-neck portion 32 tends to be unsealed in a situation that must be maintained, and the slit is positioned excessively downward from the outer periphery of the top surface of the top wall 8, the container lid 2 is placed in the container. Or the container lid 2 is once detached from the container's mouth / neck part 32 and mounted again on the container's mouth / neck part 32 to temporarily attach the container's mouth / neck part 32 to the mouth / neck part 32 of the container. Sealed state In, even if the internal pressure of the container is excessively increased, the internal pressure of the container without the container closure 2 is always sufficiently reliably deformed tends to not sufficiently reliably opened.

  Examples of the present invention and comparative examples will be described below.

In Example 1, a container lid body was formed from a 0.25 mm aluminum-based alloy thin plate, and five container lids having the form shown in FIGS. 1 to 3 were produced. The diameter of the skirt wall of the container lid was 38.4 mm. The internal pressure releasing means disposed on the skirt wall of the container lid was composed of a slit having a circumferential length Ws of 7 mm. The slit was positioned below Hs which is 2.1 mm from the outer periphery of the top surface of the top wall.

  A chromic acid-treated steel sheet container (Toyo Seikan Co., Ltd.) having a mouth and neck portion as shown in FIG. 2, having a nominal diameter of 38 mm and a nominal volume of 200 ml, and having a thermoplastic resin coating on both sides. Co., Ltd.) was filled with 190 ml of 75 ° C. water, and then the container lid was fitted on the mouth and neck, and the container neck was attached to the mouth and neck as described above to seal the mouth and neck. . The container with the mouth and neck sealed with a container lid was retorted (heat sterilized) at 123 ° C. for 20 minutes, and then allowed to stand at room temperature of 23 ° C. for 3 days.

Thereafter, the internal pressure of the container was increased using the internal pressure increasing device in a state where the container lid was attached to the mouth and neck of the container as required. Such an internal pressure raising device has an insertion needle having a flow passage for circulating nitrogen gas, a pressure detector for detecting the pressure of the nitrogen gas, and a control valve for controlling the flow rate of the nitrogen gas. The insertion needle of the internal pressure raising device configured as described above is inserted into the bottom of the container prepared as described above, and nitrogen gas is caused to flow into the container through the flow path, so that the internal pressure in the container is increased. Increased at 5 psi / sec. Then, due to the excessively increased internal pressure of the container, the lid body starts to be deformed around the slit which is the internal pressure releasing means, and the internal pressure of the container when the internal pressure of the container is released is detected by the pressure detector of the internal pressure increasing device. Measured with Such an internal pressure increase test was conducted on all five container lids as test samples. The measurement results were as shown in Table 1 below. In Example 1, when the internal pressure of the container is released, the measurement results of the internal pressure of the container are 0.65, 0.68, 0.64, 0.69, and 0.64 MPa for each of the five test samples. In any test sample, the measurement result of the internal pressure is larger than the lower limit value (a value at which the container internal pressure does not reach during the retort process) of 0.3 Mpa, and therefore the retort process (heat sterilization process). At this time, the lid body was not deformed around the slit which is the internal pressure releasing means. Moreover, in any test sample, the measurement result of the internal pressure was smaller than the upper limit value (a value with which the container lid may fly), and therefore, the container lid did not fly at the time of opening. As described above, in Example 1, a sufficiently satisfactory result for practical use was obtained for any of the test samples.

  Five test samples identical to those in Example 1 were manufactured except that the internal pressure releasing means disposed on the skirt wall of the container lid was constituted by a slit having a circumferential length Ws of 14 mm.

  An internal pressure increase test was performed under the same conditions as in Example 1 using the container lid, which was a test sample configured as described above. The measurement results were as shown in Table 1 below. In Example 2, when the internal pressure of the container is released, the measurement result of the internal pressure of the container is 0.32, 0.35, 0.31, 0.33, and 0.33 MPa for each of the five test samples. In any test sample, the measurement result of the internal pressure is larger than the lower limit value (a value at which the container internal pressure does not reach during the retort process) of 0.3 Mpa, and therefore the retort process (heat sterilization process). At this time, the lid body was not deformed around the slit which is the internal pressure releasing means. Moreover, in any test sample, the measurement result of the internal pressure was smaller than the upper limit value (a value with which the container lid may fly), and therefore, the container lid did not fly at the time of opening. As described above, in Example 2, a sufficiently satisfactory result was obtained in any test sample.

[Comparative Example 1]
Five test samples identical to those in Example 1 were prepared except that the internal pressure releasing means was not provided on the skirt wall of the container lid.

  An internal pressure increase test was performed under the same conditions as in Example 1 using the container lid, which was a test sample configured as described above. The measurement results were as shown in Table 1 below. In this comparative example 1, the measurement results of the internal pressure of the container when the internal pressure of the container was released were 0.92, 0.87, 0.88, 0.90 and 0.94 MPa for each of the five test samples. In any of the test samples, the measurement result of the internal pressure is larger than the lower limit value (a value at which the container internal pressure does not reach during retort processing) of 0.3 Mpa, and no internal pressure release means is provided. Therefore, the lid body was not deformed during the retort process (heat sterilization process). However, in any of the test samples, the measurement result of the internal pressure was larger than the upper limit value (a value at which the container lid could fly), and therefore the container lid flew before opening. As described above, in Comparative Example 1, results having practical problems were obtained in any of the test samples.

[Comparative Example 2]
Five test samples identical to those in Example 1 were manufactured except that the internal pressure releasing means disposed on the skirt wall of the container lid was constituted by a slit having a circumferential length Ws of 5 mm.

  An internal pressure increase test was performed under the same conditions as in Example 1 using the container lid, which was a test sample configured as described above. The measurement results were as shown in Table 1 below. In this comparative example 2, the measurement results of the internal pressure of the container when the internal pressure of the container is released are 0.78, 0.75, 0.77, 0.80 and 0.77 MPa for each of the five test samples. In any test sample, the measurement result of the internal pressure is larger than the lower limit value (a value at which the container internal pressure does not reach during the retort process) of 0.3 Mpa, and therefore the retort process (heat sterilization process) At that time, the lid body did not deform around the slit that is the internal pressure release means, but the measurement result of the internal pressure in any test sample is the upper limit value (the value that the container lid may fly) The container lid flew before opening or when opening. As described above, in Comparative Example 1, results having practical problems were obtained in any of the test samples.

[Comparative Example 3]
Five test samples identical to those in Example 1 were manufactured except that the internal pressure releasing means disposed on the skirt wall of the container lid was constituted by a slit having a circumferential length Ws of 18 mm.

  An internal pressure increase test was carried out under the same conditions as in Example 1 using the container lid, which was a test sample configured as described above. The measurement results were as shown in Table 1 below. In this comparative example 3, the lid main body is deformed by the internal pressure of the container at the time of the retort process (thermal sterilization process), and the internal pressure increase test after the retort process is performed. It was impossible. As described above, in Comparative Example 3, results having practical problems were obtained in any of the test samples.

実用性（○：実用上満足 ×：実用上問題有）
問題点（Ａ：問題無 Ｂ：レトルト処理の際に蓋本体がスリットを中心として変形
Ｃ：容器蓋が飛翔）

Practicality (○: Satisfactory for practical use ×: Problem in practical use)
Problems (A: No problem B: The lid body deforms around the slit during retort processing C: The container lid flies)

The front view which shows a part by a cross section in the state before mounting | wearing the container neck comprised according to this invention to the mouth neck part of a container. The front view which shows a part in cross section in the state which mounted | wore the container neck shown in FIG. FIG. 2 is a front view showing a part in a sectional view in a state where a lid body in the container lid shown in FIG. 1 is deformed around a slit which is an internal pressure releasing means to release the container internal pressure when the container internal pressure rises excessively.

Explanation of symbols

2: Container lid 4: Lid body 6: Liner 8: Top wall 10: Skirt wall 26: Concave portion 28: Convex portion 31: Internal pressure releasing means 32: Mouth and neck portion

Claims (2)

A container lid fitted to a container having a nominal diameter of the mouth and neck of 38 mm;
A lid body made of a thin metal plate having a top wall and a skirt wall that hangs down from the periphery of the top wall. In the container lid to be formed,
A slit extending in the circumferential direction is formed in the concave portion in the concave-convex shape portion,
The skirt wall is provided with an internal pressure releasing means that is located above the concavo-convex shape portion and that includes at least one slit extending in the circumferential direction, and the skirt wall includes the slits constituting the internal pressure releasing means. The circumferential length Ws is 7 to 14 mm.
A container lid characterized by that.   2. The container lid according to claim 1, wherein the slit constituting the internal pressure releasing means is positioned below Hs that is 1.0 to 3.0 mm from the outer peripheral edge of the top surface of the top wall.

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