JP7703389B2 - Hinge Cap - Google Patents

Description

The present invention relates to a hinge cap with gas barrier properties, and in particular to a hinge cap that can stably form the area in which the gas barrier layer is layered.

In the past, food containers with excellent gas barrier properties that block oxygen and other substances contained in the air have been proposed to maintain the flavor of the contents, such as seasonings, and a hinge cap with gas barrier properties is known as a corresponding cap (see, for example, Patent Document 1).

However, the hinge cap described in the above Patent Document 1 has a partition wall with a removable section defined by a breakable weakened thin section on the cap body that is attached to the mouth of the container body in order to ensure the sealing of the container body, and the cap is opened to open the spout by pulling up a pull ring provided on the removable section. Therefore, when pulling up the pull ring to break the weakened thin section, it is difficult for users with weak finger strength to open the cap.

For this reason, a hinge cap has been known in which, instead of pulling up with a pull ring, a transition plug section defined by a thin-walled weakened section is provided in the bulkhead of the cap body as the intended opening for the spout, and the transition plug section is attached to the top lid when the lid is first closed, and the transition plug section is pulled up as the top lid is opened, breaking the thin-walled weakened section, thereby opening the cap (see, for example, Patent Document 2).

JP 2020-189676 A JP 2021-84659 A

However, the hinge cap described in Patent Document 2 above has a gate position that is offset from the center of the cap body to the opposite side of the hinge during molding, and furthermore, because a thin, weakened portion is formed, the flow of resin injected from the gate is not uniform, causing the placement balance of the gas barrier layer that is layered as an intermediate layer inside the cap body to be lost.

The present invention aims to solve the above problems by providing a hinge cap that can stably form an area in which a gas barrier layer is layered as an intermediate layer within the base layer of the cap body, even if the gate position during molding is shifted from the center to the opposite side of the hinge.

In order to solve the above-mentioned problems, the present invention provides a hinge cap comprising a cap body which is attached to the mouth of a container body and has a transition plug portion defined by a breakable thin-walled weakened portion in a partition wall which seals the mouth, and an upper lid which is connected to the cap body via a hinge and which pulls up the transition plug portion when the lid is opened, wherein the transition plug portion comprises a bottom wall which is connected to the partition wall via the thin-walled weakened portion, a pull-up portion which stands upright from the bottom wall and has a molding gate formed at a position shifted from the center of the cap body to the opposite side to the hinge, and a reinforcing rib which protrudes from the pull-up portion toward the bottom wall on the central side, and wherein the cap body is configured such that the thickness of the partition wall is made thicker from the gate toward the hinge side than other parts of the partition wall so that a gas barrier layer is layered as an intermediate layer in the base layer of the partition wall by co-injection molding, thereby adjusting the flow rate of resin injected from the gate to the periphery.

As an embodiment of the hinge cap, the transition plug portion is characterized in having a thick-walled protrusion formed on the underside of the bottom wall with a constant width from the gate to the thin-walled weakened portion on the hinge side and bulging downwardly so as to have a thickness thicker than the thickness of other portions of the bottom wall, and the partition is characterized in having a thick-walled underside protrusion on the hinge side of the outer underside of the thin-walled weakened portion, which is protruded downwardly so as to have a thickness thicker than the thickness of other portions on the outer side of the thin-walled weakened portion, and the thick-walled protrusion is characterized in having a thickness thicker than the thick-walled underside protrusion.

By adopting the above-mentioned configuration, the hinge cap of the present invention can adjust the flow of resin injected from the gate to the periphery by making the thickness of the partition wall from the gate toward the hinge side thicker than other parts of the partition wall , even if the gate position during molding is shifted from the center to the opposite side of the hinge, so that a gas barrier layer can be stably formed as an inner layer in the base material layer of the cap body as an intermediate layer in the partition wall .

1A and 1B are diagrams showing a state before opening in which a hinge cap according to an embodiment of the present invention is attached to a container body, in which (a) is a side cross-sectional view and (b) is an enlarged view of a main part of (a). 1A and 1B are diagrams showing a molded state of a hinge cap according to an embodiment of the present invention, in which FIG. 1A and 1B are diagrams showing a cap body of a hinge cap according to an embodiment of the present invention, in which FIG.

Next, the hinge cap of the present invention will be described with reference to the drawings in the following embodiments.
In the following description, when looking at FIG. 1(a), the left direction is referred to as the "front side (opposite the hinge)", the right direction is referred to as the "rear side (hinge side)", the upward direction is referred to as the "top", and the downward direction is referred to as the "bottom".

In Figure 1, A is a cap body that is attached to a container body E and has a gas barrier layer D inner layered within a base material layer, and B is a top lid that is connected to the cap body A via a hinge C so as to be able to be opened and closed freely, and the cap body A, the top lid B, and the hinge C form a hinge cap.
An engaging ridge 2 is provided on the outer periphery of the mouth 1 of the container body E.

As shown in Figures 1 to 3, the cap body A is composed of an attachment part 5 that is attached to the mouth part 1 of the container body E, a pouring tube 6 that is erected inside the attachment part 5, and a partition wall 7 that is connected inward from the attachment part 5 and seals the mouth part 1.

The mounting portion 5 is suspended from the outer peripheral edge of the partition 7, with a pouring tube 6 erected inside the upper end, and comprises an inner tube 10 whose outer circumference is inserted into the inner circumference of the mouth 1 of the container body E, an outer tube 11 whose inner circumference engages with the outer circumference of the mouth 1, and a ring-shaped lid engagement portion 12 connected at the upper ends of the inner tube 10 and outer tube 11, and a bulge 13 that protrudes outward is provided at the upper part of the lid engagement portion 12.
An engaging protrusion 14 is provided on the inner periphery of the outer cylinder 11 to engage with an engaging protrusion 2 provided on the outer periphery of the mouth portion 1 .

As shown in FIG. 2, an outer peripheral cutout 15, which is roughly V-shaped in plan view, is cut from above into the outer peripheral surface near either the left or right side of the hinge C of the outer tube 11, and a slit groove 16 is recessed from above so that it extends a predetermined range in the circumferential direction on the back side (hinge C side) starting from a position separated by a thin upper portion on the inner peripheral side of the outer peripheral cutout 15.

When the hinge cap is used to dispose of the container, the top lid B is pulled down via the hinge C, and the outer circumferential cut 15 forms a vertical tear line, while the slit groove 16 forms a circumferential tear line. The outer tube 11 is broken in the circumferential direction starting from the outer circumferential cut 15, and the engagement protrusion 14 of the broken portion is disengaged from the mouth 1 of the container body E. The hinge cap can be easily separated from the container body E and disposed of separately.

The partition 7 has an upper wall portion 20 that is connected to the upper end of the inner circumference of the inner tube 10 of the attachment portion 5, and a transition plug portion 22 that is defined inside the upper wall portion 20 by a breakable thin-walled weakened portion 21 to open the spout inside the upper wall portion 20 during use.

As shown in FIG. 3, a thick underside mound 25 is formed on the rear side of the underside of the upper wall 20, which is mounded downward to a thickness b that is thicker than the thickness a of the other parts of the upper wall 20 within a range of approximately 180° with the rear side as the center, and a thick rib 26 is protruding from the underside of the rear side of the thick underside mound 25, which is connected to the inner circumference of the inner tube 10.

The transition plug portion 22 has a bottom wall 30 connected to the upper wall portion 20 via a thin-walled weakened portion 21, and a retaining upright wall 31 is erected on the upper surface of the bottom wall 30 along the inside of the thin-walled weakened portion 21, and an approximately cylindrical pull-up portion 32 is erected at a position on the front side (opposite the hinge C) of the center O of the partition wall 7.
In this embodiment, as shown in Figures 2(a) and 3(b), the tip of the bottom wall 30 on the front side is sharply shaped so as to make it easier to break the thin-walled weakened portion 21, and the front sides of the retaining vertical wall 31 and the pull-up portion 32 are also similarly formed with a sharp shape.

As shown in FIG. 3 , a thick-walled protrusion 33 is provided on the underside of the bottom wall 30, the thick-walled protrusion 33 being formed with a constant width α from the rear end of the inner periphery of the pull-up portion 32 through the center O of the partition wall 7 to the rear end, and bulging downward to a thickness c that is thicker than the thickness a of the other parts of the bottom wall 30.
In this embodiment, the thickness of the partition wall 7 is set to be in the range of thickness a<thickness b<thickness c.

As shown in FIG. 2 , a mountain-shaped engagement protrusion 35 is provided on the upper surface of the pull-up portion 32 via a step portion 34 so as to cover the cylindrical pull-up portion 32, and a reinforcing rib 36 of a constant width β is provided protruding from the back side of the pull-up portion 32, sloping downward from the top of the pull-up portion 32 toward the upper surface of the bottom wall 30.
In this embodiment, the position of the gate G for injecting resin is set to coincide with the upper end of the center of the engaging projection 35 of the lifting portion 32 when molding the hinge cap.

As shown in Figures 1 to 3, the cap body A of this embodiment is manufactured by co-injection molding so that the gas barrier layer D containing a barrier resin is the inner layer of the base material layer containing the base material resin of the cap body A, and an adhesive resin is blended into the base material resin of the base material layer, an adhesive resin is blended into the barrier resin of the gas barrier layer D, or an adhesive resin is blended into both the base material resin and the barrier resin.

In this embodiment, the gas barrier layer D is layered on the partition 7 of the cap body A, the upper part of the inner cylinder 10 of the attachment part 5 , and the lid engagement part 12 .
Incidentally, the gas barrier layer D is not formed on the pouring tube 6 of the cap body A, the lower part of the inner tube 10 of the attachment part 5, and the outer tube 11.

As the base resin for the base layer of the cap body A, known resins such as polyolefin resins such as polypropylene (PP) and polyethylene (PE), and polyethylene terephthalate resin (PET) are used.
As the gas barrier resin for the gas barrier layer D, known gas barrier resins such as ethylene vinyl alcohol copolymer (EVOH), polyvinyl alcohol (PVA), polyvinylidene chloride (PVDC), polyamide (PA), MX nylon (MXD6, etc.) and the like are used depending on the purpose of the gas barrier.
Among these, ethylene vinyl alcohol copolymer (EVOH) is preferred in terms of its barrier properties against oxygen and barrier properties against flavor and aroma.

Here, examples of blending the base resin that forms the base layer and the gas barrier resin that forms the gas barrier layer are shown below.
<Base layer><Barrierlayer>
LLDPE (Linear low density polyethylene) EVOH + LLDPE
LLDPE+EVOH EVOH
LLDPE + adhesive resin EVOH
LLDPE EVOH + adhesive resin LLDPE MXD6 + LLDPE
The blending ratio at which the bottle can be unplugged varies depending on the base resin of the base layer and the gas barrier resin of the gas barrier layer D. LDPE (low density polyethylene) may also be used as the base resin of the base layer.

As shown in Figures 1 and 2, the top cover B has a flat top wall 40 and a side wall 41 that hangs down from the periphery of the top wall 40 and is rotatably connected to the upper end of the outer periphery of the outer tube 11 of the cap body A via a hinge C at a predetermined position on the lower periphery.

The top wall 40 has a sealing tube 42 and a retaining wall 44 hanging down from the bottom surface of the sealing tube 42 on the back side of the inside of the sealing tube 42. An engagement hole 46 is opened on the front side of the center O of the top wall 40 inside the sealing tube 42. The inner circumference of the engagement hole 46 has a step at the bottom and an engagement part 43 that engages with the engagement protrusion 35 at the top of the lifting part 32.

The sealing tube 42 is arranged so that its outer periphery is in close contact with the inner periphery of the pouring tube 6 of the cap body A, and the retaining receiving wall 44 is arranged so that its tip engages or abuts with the upper end of the retaining standing wall 31 of the transition plug portion 22.
An abutment rib 45 is formed at the center of the back side of the inner periphery of the receiving wall 44, and the outer tip of the abutment rib 45 is arranged to be close to or in contact with the inner periphery of the upper end of the standing wall 31 when the lid is closed.

In this embodiment, when the lid is closed, the upper part of the engagement protrusion 35 protrudes through the engagement hole 46, and the upper part of the engagement protrusion 35 is expanded to fill the engagement hole 46 by a retaining process such as welding, and the engagement protrusion 35 is engaged with the upper surface of the engagement part 43.

An engagement recess 48 is provided around the inner periphery of the side peripheral wall 41 to engage with the bulge 13 of the lid engagement portion 12 of the cap body A to maintain the lid in the closed state.
A hinge C is connected to the outer periphery of the side peripheral wall 41 on the rear side, and a knob 49 is provided on the front side.

Next, the manner of use and the effects of this embodiment will be described.
The hinge cap of this embodiment is manufactured as a single unit by injection molding using a mold with the top cover B open relative to the cap body A, as shown in Figure 2, and at least the cap body A is formed by injecting resin from a gate G.
In this case, the hinge cap can be manufactured by co-injection molding such that, in addition to the base resin, a gas barrier layer D made of a gas barrier resin is layered internally only on the base layer of the cap body A.

Specifically, in the molding of the hinge cap of this embodiment, the base resin is first injected alone for a predetermined time, then the gas barrier resin is injected simultaneously with the base resin for a predetermined time, and then the base resin is injected alone for a predetermined time to complete the molding.
To explain the flow of resin at this time, first, the base material resin that forms the base material layer of the hinge cap is injected from gate G provided at the upper end of the attachment protrusion 35 of the cap body A in the hinge cap mold, and the base material resin passes from the attachment protrusion 35 through the pull-up portion 32 and is guided to the bottom wall 30.

At that time, since the engagement projection 35 and the lifting portion 32 are formed on the front side of the center O of the bulkhead 7, when the bulkhead 7 is molded, the resin reaches the front end, which is shorter than the back end, first. However, as shown in FIG. 2, a reinforcing rib 36 of width β is formed on the back side of the lifting portion 32 so as to extend to the top surface of the bottom wall 30. Also, as shown in FIG. 3, a thick protrusion 33 is formed on the underside of the bottom wall 30 from the back end of the inner periphery of the lifting portion 32 through the center O to the thin weakened portion 21 on the back side. Therefore, the protrusion due to the width β of the reinforcing rib 36 and the thickness c, which is thicker than the thickness a of the other bottom wall 30 formed by the thick protrusion 33, form a flow path through which the resin can easily flow. The arrival times at the front end and the back end of the bottom wall 30, which are at different distances from the gate G that injects the resin, can be made to be the same, and the resin from the bottom wall 30 of the transition plug portion 22 to the outer thin weakened portion 21 can flow uniformly regardless of the distance from the gate G.

Next, the resin flows from the bottom wall 30 through the thin weakened portion 21 , is guided to the upper wall portion 20 located outside the thin weakened portion 21 of the partition 7 , and flows into the mounting portion 5 and the pouring tube 6 .
In this case, as shown in Figure 3, a thick-walled underside mound 25 is formed on the back side half of the underside of upper wall portion 20, so that the back side has a thickness b that is thicker than the thickness a of the front side of upper wall portion 20, improving the flow of resin to the back side. In particular, thick-walled rib 26 extending from the underside of thick-walled underside mound 25 to the inner circumference of inner tube 10 of mounting portion 5 forms a flow path, making it easier for resin to flow to the back side of mounting portion 5 than to the front side.
If the base resin continues to flow in this manner, the resin will flow throughout the entire pouring tube 6 and its flow in the direction of the pouring tube 6 will be stopped, so that it will flow only into the inner tube 10 of the attachment part 5, and further, since the resin has flowed throughout the entire lower part of the inner tube 10 of the attachment part 5 and its flow toward the lower part of the inner tube 10 will be stopped, it will flow only into the lid engagement part 12 of the attachment part 5.

When a gas barrier resin is injected from a gate G simultaneously with the base resin for a predetermined time after a predetermined time from the start of injection of the base resin, the lower parts of the pouring tube 6 and the inner tube 10 of the mounting part 5 are filled with the base resin, so that the resin does not flow into these parts.
Therefore, the gas barrier layer D formed by the gas barrier resin traveling on the base resin is not formed on the lower part of the pouring tube 6 and the inner tube 10 .
Since the gas barrier layer D is not formed on the pouring tube 6 of the cap body A and the lower part of the inner tube 10 of the mounting part 5, deformation due to the difference in shrinkage rate between the gas barrier layer D and the base resin after molding is prevented, and jetting is less likely to occur on the inner surface of the pouring tube 6 and the outer peripheral surface of the lower part of the inner tube 10.

In the hinge cap of this embodiment, at least during molding of the cap body A, the reinforcing rib 36 and the thick protrusion 33 are provided on the transition plug portion 22 of the partition 7, and the thick underside mound portion 25 and the thick rib 26 are provided on the upper wall portion 20, so that the thickness of that portion is thicker than the other portions, and the flow rate of the resin injected from the gate G can be adjusted to be larger than that of other portions. Even if the gate G is formed offset from the center of the cap body A to the opposite side of the hinge, the arrival time of the resin on the front side and back side of the cap body A is uniform, and the gas barrier layer D can be uniformly layered on the cap body A, so that a hinge cap can be easily formed that suppresses partial deformation of the cap body A and has stable sealing properties.

When the top lid B of the integrally molded hinge cap is rotated around the hinge C as a fulcrum to close the cap body A, the sealing tube 42 of the top lid B fits tightly against the dispensing tube 6 of the cap body A to form a seal, and the bulge 13 of the lid engagement portion 12 of the cap body A fits into the engagement recess 48 of the top lid B to achieve the closed state shown in Figure 1.
When the upper part of the engagement protrusion 35 of the transition plug portion 22 protruding from the top wall 40 of the upper lid B is processed to prevent it from coming loose by welding or the like, the upper part of the engagement protrusion 35 expands to fill the engagement hole portion 46, and the engagement protrusion 35 engages with the upper surface of the engagement portion 43.

Next, the closed hinge cap is attached to the mouth 1 of the container body E filled with the contents, thereby forming a container with a hinge cap attached.
In this embodiment, the hinge cap is attached to the container body E by plugging, but it may be attached by screwing.

When using the hinge cap for the first time, first, with the hinge cap in the state shown in Figure 1 (a), place your fingers on the knob 49 of the top lid B and lift it up. The top lid B will then be lifted from the front side, using the hinge C as a fulcrum, and the lid engagement portion 12 of the cap body A will disengage from the engagement recess 48 of the top lid B, causing the lid to open.
In addition, by opening the top lid B, the thin-walled weakened portion 21 provided on the partition 7 of the cap body A breaks, and the transition plug portion 22 is removed from the partition 7 and then transferred to and supported by the top lid B, while the site of the removed transition plug portion 22 inside the upper wall portion 20 of the partition 7 of the cap body A becomes an outlet, making it possible to pour out the contents within the container body E.
In this embodiment, a reinforcing rib 36 is provided on the back side of the pull-up portion 32, so that stress is concentrated on the thin-walled weakened portion 21 on the front side, making it easier for the thin-walled weakened portion 21 to break, and the front tip of the bottom wall 30 has a pointed shape, making it easier for stress to be concentrated on the thin-walled weakened portion 21 on the front side.

After the contents have been used, the top lid B is closed again on the cap body A, forming a seal between the sealing tube 42 of the top lid B and the dispensing tube 6 of the cap body A, and the lid engagement portion 12 of the cap body A and the engagement recess 48 of the top lid B fit together to reseal the inside of the hinge cap, allowing the top lid B to be opened and closed repeatedly for use.
In addition, the transition plug portion 22 is held in place by the outer periphery of the retaining vertical wall 31 engaging or abutting against the inner periphery of the retaining receiving wall 44 of the upper lid B, so that the pouring outlet of the partition 7 of the cap body A is closed by the bottom wall 30 of the transition plug portion 22 held by the upper lid B.

The hinge cap of the present invention can adjust the flow of resin injected from the gate to the periphery by making the thickness of the partition wall from the gate toward the hinge thicker than other parts, even if the gate position during molding is shifted from the center to the opposite side of the hinge. This allows the gas barrier layer to be stably formed as an intermediate inner layer in the base layer of the cap body to a desired extent, making it suitable for use as a container for storing contents that require gas barrier properties, such as food, beverages, cosmetics, etc.

A Cap body B Top lid C Hinge D Gas barrier layer E Container body G Gate O Center a, b, c Wall thickness α, β Width 1 Mouth 2 Engagement protrusion 5 Mounting portion 6 Spouting tube 7 Partition 10 Inner tube 11 Outer tube 12 Lid engagement portion 13 Bulging portion 14 Engagement protrusion 15 Outer peripheral cut portion 16 Slit groove 20 Upper wall portion 21 Thin weakened portion 22 Transfer plug portion 25 Thick underside raised portion 26 Thick rib 30 Bottom wall 31 Retaining vertical wall 32 Pull-up portion 33 Thick protrusion 34 Step portion 35 Engagement protrusion 36 Reinforcing rib 40 Top wall 41 Side peripheral wall 42 Sealing tube 43 Engagement portion 44 Retaining receiving wall 45 Abutment rib 46 Engagement hole portion 48 Engagement recess 49 Knob

Claims (4)

A hinge cap is provided which is provided with a cap body which is attached to the mouth of a container body and has a transition plug part defined by a breakable thin-walled weakened part in a partition wall which closes the mouth, and a top lid which is connected to the cap body via a hinge and which lifts up the transition plug part when the lid is opened,
the transition plug portion includes a bottom wall connected to the partition wall via a thin-walled weakened portion, a pull-up portion erected from the bottom wall and having a molding gate formed at a position shifted from the center of the cap body to the opposite side to the hinge, and a reinforcing rib extending from the pull-up portion toward the bottom wall on the center side ;
The cap body is a hinge cap, characterized in that the thickness of the partition wall from the gate toward the hinge side is made thicker than other parts of the partition wall so that a gas barrier layer is layered as an intermediate layer within the base material layer of the partition wall by co-injection molding, and the flow rate of resin injected from the gate to the periphery is adjusted. The hinge cap according to claim 1, characterized in that the transition plug portion is formed on the underside of the bottom wall with a constant width from the gate toward the thin-walled weakened portion on the hinge side, and has a thick-walled protrusion that bulges downward so as to have a thickness thicker than that of other portions of the bottom wall . 3. A hinge cap as described in claim 1 or 2, characterized in that the partition wall has a thick underside protrusion on the hinge side of the outer underside of the thin-walled weakened portion so that the thickness is thicker than the thickness of other parts of the outer side of the thin-walled weakened portion. 4. The hinge cap according to claim 3 , wherein the thick protrusion is thicker than the thick undersurface protrusion .

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