JP2007145341A - Container lid made of synthetic resin - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a container lid made of a synthetic resin designed such sufficient washing effect can be achieved by washing the container lid (2) with washing water, thereby avoiding to the maximum the contents remaining in the circumferential break line (8) of the container lid, and an amount of synthetic resin required for molding can be significantly reduced without an excessive decrease in strength by avoiding the need to replace various composing elements of an existing attaching device. <P>SOLUTION: A plurality of recesses (44) are formed in the external circumferential face of a skirt wall (6) at intervals in the circumferential direction so as to extend in an axial direction from the main portion (10) of the skirt wall, beyond the circumferential break line, to a tamper evident skirt portion (12). Thus, the thickness of the skirt wall is partially reduced in the recesses. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention comprises a synthetic resin container lid, more specifically, a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, and a circumferential rupture line extending in the circumferential direction is formed on the skirt wall. The skirt wall is divided into a main part above the circumferential break line and a tamper evidence hem below the circumferential break line, and the skirt wall is surrounded by the main part of the skirt wall and / or the top wall. The present invention relates to a synthetic resin container lid in which a plurality of cleaning slits are formed at intervals in the direction.

As a container lid for a beverage container, a synthetic resin container lid formed from a polyolefin-based synthetic resin such as polyethylene or polypropylene or other appropriate synthetic resin is widely used as disclosed in Patent Document 1 below. It is provided. Such a synthetic resin container lid includes a top wall and a cylindrical skirt wall depending from the periphery of the top wall. The skirt wall is formed with a circumferential break line extending in the circumferential direction, and the skirt wall is divided into a main part above the circumferential break line and a tamper evidence skirt below the circumferential break line. Has been. A female thread is formed on the inner peripheral surface of the main part of the skirt wall, and a plurality of locking pieces are formed on the inner peripheral surface of the tamper evidence skirt at intervals in the circumferential direction. Further, a plurality of cleaning slits are formed at the upper end of the main part of the skirt wall at intervals in the circumferential direction.
Japanese Patent No. 3213842

  The synthetic resin container lid as described above has a mouth-and-neck portion whose upper surface is opened, and a male jaw and a locking jaw portion located below the male screw on the outer peripheral surface of the mouth-and-neck portion. And applied to the container in which is formed. After filling the container with a content such as a soft drink, the container lid is fitted on the mouth and neck and rotated in the closing direction, and the female thread on the container lid is screwed onto the male thread on the mouth and neck. The locking piece of the container lid is elastically passed through the locking jaw of the mouth / neck and is engaged therewith. Thus, after the mouth and neck are sealed with the container lid, washing water, which is clean water, is applied to the container lid. The washing water passes through the washing slit formed in the container lid, enters between the inner circumferential surface of the container lid and the outer circumferential surface of the mouth and neck, flows down, overflows from the inside of the container, and flows to the outer circumference of the mouth and neck. The contents adhering to the surface and the contents transferred from the outer peripheral surface of the mouth and neck to the inner peripheral surface of the container lid are washed away.

  However, the conventional synthetic resin container lid as described above has the following problems to be solved. First, according to the experience of the present inventors, even if the mouth and neck of the container is sealed with a container lid and then washed with water applied to the container lid, a sufficient cleaning effect is not necessarily obtained. In particular, the contents tend to remain in the circumferential break line formed in the skirt wall of the container lid. Secondly, the amount of synthetic resin used for molding the plastic resin container lid should be reduced as much as possible, thereby reducing manufacturing costs and reducing the required cooling time in the molding process to increase manufacturing efficiency. Is desired. For this purpose, it is intended to reduce the thickness of the skirt wall and / or the top wall. However, if the thickness of the skirt wall and / or the top wall is simply reduced, (a) the strength is excessively reduced. (B) The inner diameter of the skirt wall needs to have a dimension corresponding to the outer diameter of the mouth and neck of the container. Therefore, if the thickness of the skirt wall is reduced, the outer diameter of the skirt wall inevitably decreases, This causes a problem that various components of an existing mounting device for mounting the container lid on the mouth / neck portion of the container have to be replaced.

  The present invention has been made in view of the above-mentioned facts, and the main technical problem thereof is to apply the washing water to the container lid so that the contents remain in the circumferential break line of the container lid as much as possible. The amount of synthetic resin required for molding can be avoided to achieve a sufficient cleaning effect, and also avoids the need to replace various components of existing mounting equipment without excessively reducing strength It is an object of the present invention to provide a new and improved synthetic resin container lid capable of greatly reducing the above.

  As a result of diligent research, the inventors of the present invention have a circumferential interval on the outer peripheral surface of the skirt wall, and extend in the axial direction from the main part of the skirt wall to the tamper evidence hem part beyond the circumferential break line. It has been found that the above technical problem can be achieved by forming a plurality of recesses and locally reducing the thickness of the skirt wall in the recesses.

That is, according to the present invention, the synthetic resin container lid that achieves the above technical problem includes a top wall and a cylindrical skirt wall that hangs down from the periphery of the top wall, and the skirt wall has a circumferential direction. An extending circumferential break line is formed, and the skirt wall is divided into a main part above the circumferential break line and a tamper evidence skirt below the circumferential break line, In a synthetic resin container lid in which a plurality of cleaning slits are formed in the main part of the skirt wall and / or the top wall at intervals in the circumferential direction,
The outer peripheral surface of the skirt wall is formed with a plurality of recesses arranged at intervals in the circumferential direction, and the thickness of the skirt wall is locally reduced in the recesses, Provided is a synthetic resin container lid characterized in that each of the recesses extends in the axial direction from the main part of the skirt wall to the tamper evidence skirt part beyond the circumferential break line. The

  Preferably, 4 to 16 recesses are formed at intervals in the circumferential direction, and the recesses occupy 2/5 to 3/5 of the entire circumferential direction. The cleaning slit is preferably disposed in the recess. Preferably, the recess extends from the upper end of the main portion of the skirt wall, and the cleaning slit is disposed at the upper end of the main portion of the skirt wall. A number of protrusions extending in the axial direction from the upper end portion of the main portion to the vicinity of the circumferential break line are formed at intervals in the circumferential direction at portions other than the concave portion of the main portion of the skirt wall. Is convenient. It is preferable that at least one protrusion extending in the axial direction from the upper end of the main portion to the vicinity of the circumferential break line is also formed in the concave portion in the main portion of the skirt wall.

  In the synthetic resin container lid of the present invention, the reason is not necessarily clear, but as will be clearly understood from the examples and comparative examples described in detail later, by applying cleaning water to the container lid, A sufficient cleaning effect can be achieved by avoiding as much as possible the content remaining in the circumferential break line. In addition, since the recesses are formed in the skirt wall at intervals in the circumferential direction, the strength reduction of the skirt wall can be sufficiently suppressed or avoided, and the amount of synthetic resin required for molding can be greatly reduced. . Since the outer diameter of the skirt wall at the site where the recess is not formed is unchanged, the need to replace various components of the existing mounting device is avoided.

  Hereinafter, a preferred embodiment of a synthetic resin container lid constructed according to the present invention will be described in more detail with reference to the accompanying drawings.

  Referring to FIGS. 1 and 2, a container lid constructed in accordance with the present invention, generally designated 2, which can be formed from a polyolefin-based synthetic resin such as polyethylene or polypropylene or other suitable synthetic resin. A circular top wall 4 and a substantially cylindrical skirt wall 6 depending from the periphery of the top wall 4 are provided. The skirt wall 6 is formed with a circumferential break line 8 extending in the circumferential direction. The skirt wall 6 has a main portion 10 above the circumferential break line 8 and a tamper shrimp below the circumferential break line 8. It is partitioned into a dent skirt 12. As clearly understood from FIG. 2, an annular shoulder surface 14 facing downward is formed on the inner peripheral surface of the skirt wall 6, and a relatively short ridge 16 extending downward from the annular shoulder surface 14 is formed. A plurality are formed at intervals in the circumferential direction. The circumferential break line 8 is formed by applying a cutting blade (not shown) from the outer peripheral surface of the skirt wall 6 at the upper part in the axial direction of the ridge 16 so that at least a part of the ridge 16 remains. It is formed by cutting. The portion of the ridge 16 that remains without being cut constitutes a so-called bridge portion, and the tamper evidence skirt portion 12 is connected to the main portion 10 via the bridge portion.

  The main portion of the outer peripheral surface of the main portion 10 of the skirt wall 6 is substantially cylindrical, but a truncated cone-shaped portion 18 is disposed at the lower portion of the outer peripheral surface of the main portion 10. The upper end of the outer peripheral surface of the tamper evidence skirt 12 has a substantially cylindrical shape, but the portion below the upper end has a truncated cone shape. The form of the outer peripheral surface of the main part 10 of the skirt wall 6 and the tamper evidence skirt part 12 will be described in detail later.

  In the illustrated embodiment, a female thread 20 is formed on the inner peripheral surface of the main portion 10 of the skirt wall 6 as clearly shown in FIG. The female thread 20 is formed with a notch 22 extending in the axial direction at an appropriate interval in the circumferential direction. The notch 22 constitutes a so-called air passage when the mouth and neck of the container is opened.

  An annular shoulder surface 26 facing downward is formed at the upper part of the inner peripheral surface of the tamper evidence skirt 12, and an annular shoulder surface 28 facing downward is formed at the lower part of the inner peripheral surface of the tamper evidence skirt 12. Yes. Then, between the annular shoulder surface 26 and the annular shoulder surface 28, the inner peripheral surface of the tamper evidence skirt 12 extends downward inward in the radial direction, and then outwards radially outward. It is inclined to the direction. A plurality of locking pieces 30 projecting from the minimum inner diameter portion of the inner peripheral surface of the tamper evidence skirt portion 12 so as to incline upward in the radial direction therefrom at equal intervals in the circumferential direction. It is attached.

  As can be understood by referring to FIG. 2, an inner cylindrical seal piece 32, an annular contact piece 34, and an outer cylindrical seal piece 36 are formed on the peripheral portion of the lower surface or inner surface of the top wall 4. The inner cylindrical seal piece 32 extends from the inner surface of the top wall 4 inclining outward in the radial direction downward, and then extends inclining somewhat inward in the radial direction downward. The annular contact piece 34 is positioned immediately inside the outer cylindrical seal piece 32 when viewed in the radial direction, and is constituted by a bulging portion bulged downward from the inner surface of the top wall 4. The outer cylindrical seal piece 36 is spaced apart from the inner cylindrical seal piece 32 by a predetermined distance in the radial direction, and extends from the inner surface of the top wall 4 to incline downward in the radial direction. As clearly understood by referring to FIG. 3 together with FIG. 2, the central portion of the inner surface of the top wall 4 is relatively thin compared to the peripheral portion, and a circular protrusion 38 is provided at the center for reinforcement. An annular protrusion 40 is disposed adjacent to the base of the inner cylindrical seal piece 32, and eight protrusions 42 extending radially from the circular protrusion 38 to the annular protrusion 40 are also disposed.

  1 to 3, the container lid 2 constructed according to the present invention has a plurality of recesses 44 formed on the outer peripheral surface of the skirt wall 6 at intervals in the circumferential direction. It is important that In the illustrated embodiment, each of the recesses 44 extends axially from the upper end of the main portion 10 of the skirt wall 6 beyond the circumferential break line 8 to the axially intermediate portion of the tamper evidence skirt 12. The circumferential width of the recess 44 is substantially the same over the entire axial direction. The recesses 44 are formed in the circumferential direction at regular intervals of 4 to 16, particularly 8 to 14, and the area occupied by the recesses 44 in the circumferential direction is about 2/5 to 3/5 of the entire circumferential direction. Preferably there is. In the illustrated embodiment, twelve concave portions 44 are formed at equal intervals in the circumferential direction, and the circumferential width of each of the concave portions 44 is substantially the same as the interval between the concave portions 44, and thus the concave portions in the circumferential direction. 44 occupies 1/2 of the whole circumferential direction. The depth t of the recess 44 can be appropriately set in consideration of the thickness of the skirt wall 6 or the ease of punching, but is generally about 0.10 to 0.80 mm. . When the depth t of the recess 44 is excessive, the strength of the skirt wall 6 is excessively decreased. On the other hand, if the depth t of the recess 44 is too small, the amount of reduction in the used synthetic resin material becomes slight.

  In the illustrated embodiment, as clearly understood by referring to FIGS. 1 and 3, a portion other than the concave portion 44 in the main portion 10 of the skirt wall 6, that is, a portion between the adjacent concave portions 44 is conventionally provided. Similarly to the outer peripheral surface of the main part of the skirt wall of the container lid, a plurality of relatively small protrusions 46 extending in the axial direction are arranged at intervals in the circumferential direction. Further, at least one (in the illustrated case, one) protrusion 48 is disposed in the recess 44 itself. The protrusion 48 extends in the axial direction from the upper end portion of the main portion 10 of the skirt wall 6 to the lower end portion, that is, in the vicinity of the circumferential break line 8.

  In the illustrated synthetic resin container lid 2, the main portion 10 of the skirt wall 6 is also provided with a plurality of cleaning slits 50 extending in the circumferential direction at intervals in the circumferential direction. The cleaning slit 50 is disposed in the concave portion 44, and more specifically, is disposed at the upper end portion of the concave portion 44 (therefore, the upper end portion of the main portion 10). Such a cleaning slit 50 can be formed by cutting a required portion of the skirt wall 6 with a cutting blade. The cleaning slit 50 is conveniently disposed in the recess 44, but can also be disposed in the portion between the recesses 44 in the main portion 10 of the skirt wall 6 or in the top wall 4 if desired. Moreover, the form extended not in the circumferential direction but in the axial direction may be used.

  FIG. 4 also shows a part of the container to which the container lid 2 is applied together with the container lid 2. A container that can be formed from an appropriate synthetic resin such as polyethylene terephthalate or glass has a generally cylindrical mouth-and-neck portion 52 as a whole. A male thread 54 and an annular locking jaw part 56 positioned below the male thread 54 are formed on the outer peripheral surface of the mouth and neck part 52 whose upper surface is opened. When the container lid 2 is attached to the mouth-and-neck portion 52 of the container and the mouth-and-neck portion 52 is sealed after the container is filled with the contents, That is, in FIG. 4, it is rotated clockwise with a required rotational torque as viewed from above. Thus, the female thread 20 of the container lid 2 is gradually screwed into the male thread 54 of the mouth-and-neck portion 52, and the container lid 2 is lowered with rotation. The locking piece 30 formed on the tamper evidence skirt 12 is elastically deformed radially outward to get over the locking jaw 56 formed on the mouth-neck 52 and then elastically restored. Then, it is locked to the locking jaw portion 56. The inner cylindrical seal piece 32 formed on the inner surface of the top wall 4 of the container lid 2 is made to enter the mouth / neck portion 52 and is brought into close contact with the upper end portion of the inner peripheral surface of the mouth / neck portion 52 to be somewhat radially inward. The annular contact piece 34 is brought into contact with the upper end surface of the mouth-and-neck portion 52 and somewhat compressed, and the outer cylindrical seal piece 36 is brought into close contact with the upper end portion of the outer-peripheral surface of the mouth-and-neck portion 52 It is somewhat deflected radially outward, thus sealing the mouth and neck 52.

  After the container lid 2 is attached to the mouth-and-neck portion 52 of the container and the mouth-and-neck portion 52 is sealed, a shower of washing water that is clean water is poured into the container lid 2. As a result, the cleaning water passes through the cleaning slit 50 and enters between the inner surface of the skirt wall 6 of the container lid 2 and the outer peripheral surface of the mouth / neck portion 52 of the container, and flows down between them, thus the mouth / neck portion 52. The contents adhering to the outer peripheral surface and the inner peripheral surface of the skirt wall 6 are washed away. A plurality of recesses 44 extending in the axial direction from the main portion 10 to the tamper evidence skirt 12 on the outer peripheral surface of the skirt wall 6 are formed at intervals in the circumferential direction. According to the container lid 2, the reason is not necessarily clear, but as clearly understood from the examples and comparative examples described later, without leaving the contents in the circumferential break line 8 of the container lid 2, A sufficiently good cleaning can be achieved.

  When opening the mouth / neck portion 52 of the container, the container lid 2 is rotated in the opening direction, that is, counterclockwise as viewed from above in FIG. In this way, the tamper evidence skirt 12 has the locking piece 30 formed on the inner peripheral surface thereof locked to the locking jaw portion 56 formed on the outer peripheral surface of the mouth-and-neck portion 52. The other part of the container lid 2 is raised as the screwing of the female thread 20 with respect to the male thread 54 is released by rotation. Accordingly, a considerable stress is generated in the circumferential break line 8 formed in the skirt wall 6, more specifically, the bridge portion, the bridge portion is broken, and the tamper evidence skirt portion 12 is separated from the main portion 10. It is. Thereafter, the portion of the container lid 2 other than the tamper-evidence skirt portion 12 is freely raised with rotation and detached from the mouth-and-neck portion 52, and thus the mouth-and-neck portion 52 is opened. In the illustrated embodiment, when opening the mouth-and-neck portion 52, the circumferential break line 8 is broken over the entire circumference so that the tamper evidence skirt 12 is completely separated from the main portion 10. The dent skirt 12 is allowed to remain in the mouth / neck portion 52 without being detached from the mouth / neck portion 52, but if desired, at least one of the bridging portions in the circumferential break line 8 can be maintained without being broken. An axial break line extending in the axial direction is formed in the tamper evidence skirt 12 and the axial break line is broken when the mouth neck 52 is opened so that the tamper evidence skirt is broken. The tamper-evidence hem 12 connected to the main part 10 through the strong bridge portion in which the part 12 is expanded from the endless annular form to the end-band form and maintained without being broken is also the mouth and neck part It may be allowed to as detached from 2.

  The following facts should also be noted for the container lid 2 as described above constructed in accordance with the present invention. Since a plurality of recesses 44 are formed on the outer peripheral surface of the skirt wall 6, the amount of synthetic resin used to mold the container lid 2 by the volume of the recesses 44 compared to the case where the recesses 44 are not formed. Is reduced. On the other hand, when the total thickness of the skirt wall 6 is uniformly reduced to reduce the amount of synthetic resin used, the strength of the skirt wall 6 is considerably reduced, but a plurality of concave portions 44 are spaced apart in the circumferential direction. The amount of the synthetic resin used is reduced to reduce the strength of the skirt wall 6 due to, for example, an impact applied to the boundary region between the top wall 4 and the skirt wall 6. Further, the recesses 44 are formed at intervals in the circumferential direction, and there is no change in the outer diameter of the skirt wall 6 in the region between the recesses 44. Therefore, when the container lid 2 is attached to the mouth and neck of the container For the components such as the locking means to be locked to the outer peripheral surface of the container lid 2, a mounting device that has been used conventionally can be used as it is without any particular change.

Next, examples and comparative examples of the container lid of the present invention will be described.
Example 350 ml of a polyethylene terephthalate heat-resistant container with a nominal volume of 350 ml sold under the trade name “Crystal Mouth / Square Bottle” from Toyo Seikan Co., Ltd. was filled with 350 ml of water, and then the outer periphery of the mouth and neck of the container The whole surface was sprayed with brown oolong tea. Thereafter, a container lid having a form as shown in FIGS. 1 to 4 was attached to the mouth and neck of the container to seal the mouth and neck. The container lid is made of polypropylene with a nominal diameter of 28 mm, and 12 recesses are formed on the outer peripheral surface of the skirt wall. Each recess has a circumferential width of 3.60 mm and an axial length of 14 mm. The depth of the recess was 0.10 mm and the thickness of the skirt wall in the recess was 0.56 mm. Each of the recesses was formed with one ridge extending in the axial direction at the center in the width direction. The protrusion height of the ridge was 0.30 mm and the length in the axial direction was 12.50 mm. The circumferential rupture line in the skirt is formed by applying a rotary cutting blade from the outer peripheral surface of the skirt, and the circumferential rupture line in the container lid sold under the trade name “28NC flap hot” by Nippon Crown Cork Co., Ltd. And substantially the same form. Immediately after attaching the container lid to the mouth and neck of the container, the container was laid down for 30 seconds. Next, the container is placed on a conveyor belt conveyor in an upright state, and while being conveyed at a speed of 228 mm / min, water at 75 ° C. is sprayed from the top of the container toward the container lid for 3 minutes and 30 seconds, 55 ° C. water was jetted for 4 minutes 30 seconds, then 40 ° C. water was jetted for 4 minutes 30 seconds, and 35 ° C. water was jetted for 6 minutes. Each of the water jets is 120 liters of clean water at the required temperature in a jet tank in which the horizontally extending bottom plate has a diameter of 8.0 mm and the nozzle is formed with a pitch of 200 mm and a width of 170 mm. This was accomplished by spraying from the spray nozzle with a feed per minute. The vertical interval between the top wall of the container lid and the spray nozzle was 360 mm. Thereafter, the container was left in the room for 24 hours, after which an opening was formed on the bottom of the container to discharge water, and the container was stored in a drying room at room temperature of 40 ° C. for 24 hours. After that, pay attention to the appearance of the container lid, whether or not brown stains due to oolong tea are observed in the circumferential break line on the skirt wall, and if so, the length of the stain (multiple stains are observed) In some cases, their total length) was measured. The results of performing the experiment as described above for the 20 container lids are as shown in Table 1 below.

Comparative Example No recess was formed on the outer peripheral surface of the skirt wall in the container lid, and the outer peripheral surface of the skirt wall was substantially the same over the entire circumferential direction, as in the examples. Experiments were performed on 20 container lids. The results were as shown in Table 1 below.

The front view which shows suitable embodiment of the container lid comprised according to this invention. The longitudinal cross-sectional view of the container lid of FIG. FIG. 3 is a cross-sectional view of the container lid of FIG. 1 taken along line III-III in FIG. The front view which shows the state which mounted | wore the mouth neck part of the container with the container lid of FIG.

Explanation of symbols

2: Container lid 4: Top wall 6: Skirt wall 8: Circumferential break line 10: Main part of skirt wall 12: Tamper evidence hem 44: Recess 46: Projection 48: Projection 50: Cleaning slit 52: Container Mouth and neck

Claims (6)

A top skirt wall and a cylindrical skirt wall depending from the peripheral edge of the top surface wall, and the skirt wall is formed with a circumferential break line extending in the circumferential direction, and the skirt wall is formed in the circumferential break line. And a tamper-evidence skirt portion below the circumferential break line, and a plurality of the skirt wall main portion and / or the top wall are spaced apart in the circumferential direction. In a synthetic resin container lid in which a single cleaning slit is formed,
The outer peripheral surface of the skirt wall is formed with a plurality of recesses arranged at intervals in the circumferential direction, and the thickness of the skirt wall is locally reduced in the recesses, A synthetic resin container lid characterized in that each of the recesses extends in the axial direction from the main part of the skirt wall to the tamper evidence skirt part beyond the circumferential break line.   2. The synthetic resin container according to claim 1, wherein 4 to 16 recesses are formed at intervals in the circumferential direction, and the recesses occupy an area of 2/5 to 3/5 of the entire circumferential direction in the circumferential direction. lid.   The synthetic resin container lid according to claim 1 or 2, wherein the cleaning slit is disposed in the recess.   4. The synthetic resin product according to claim 3, wherein the concave portion extends from an upper end portion of the main portion of the skirt wall, and the cleaning slit is disposed at an upper end portion of the main portion of the skirt wall. Container lid.   A number of protrusions extending in the axial direction from the upper end portion of the main portion to the vicinity of the circumferential fracture line are formed at intervals in the circumferential direction at portions other than the concave portion in the main portion of the skirt wall. The synthetic resin container lid according to any one of claims 1 to 4.   6. The synthetic resin product according to claim 5, wherein the concave portion in the main portion of the skirt wall is also formed with at least one protrusion extending in the axial direction from the upper end portion of the main portion to the vicinity of the circumferential break line. Container lid.

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