JPH0645201B2 - Method for manufacturing lid for wide-mouthed container - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of application] The present invention relates to a synthetic resin in which an opening hole is provided in a lid made of a metal plate for a mouth portion of a wide-mouthed container, and the lid has a gripping piece. The present invention relates to a method for manufacturing a pull-open type lid body configured by integrally molding a closed body made of metal so as to close the opening hole, and pulling the gripping piece to open at the closed body portion.

[Conventional technology]

Conventionally, a pull-open type lid for a wide-mouthed container is formed of a single metal plate, and a cut portion is formed by engraving a thin weakening line in a closed loop shape on the lid. , A pull ring formed by separately bending a ring-shaped metal plate is caulked and fixed to a portion of the outer surface of the cut portion adjacent to the weakening line, and the pull ring is pulled to separate the cut portion. , I try to open it.

However, in the lid body thus entirely formed of a metal plate, after the cutout portion is cut off, the outer peripheral edge of the cutout portion and the inner peripheral edge of the opening hole formed by cutting the cutout portion are separated. Since the body is in a sharply angled state, the body may touch the cut-out part that has been cut off and injured, or the fingers may be injured at the inner peripheral edge of the opening when inserting or removing a finger, etc. into the opening. There are a lot of accidents such as burning, and not only there is a problem in terms of safety, but it is also an advanced technique for bending a ring-shaped metal plate into a smooth state so that people do not hurt their fingers. Therefore, there is a problem in that the manufacturing cost increases.

In view of this, in Japanese Utility Model Publication No. 54-28205 as a prior art, an opening is formed in a lid made of a metal plate, and a synthetic resin closing body with a gripping piece is attached to the lid to close the opening. Has been proposed as a lid body in which the synthetic resin closing body is opened by pulling the gripping piece. Since it is to be opened at the location of, it is possible to prevent injury with the closed body cut out from the container, and to prevent fingers from being injured at the inner peripheral edge of the opening hole, and it is possible to improve safety after opening. Since the gripping piece can be integrally molded with the lid body by a normal injection molding, there is an advantage that the manufacturing cost can be reduced.

[Problems to be Solved by the Invention]

However, since synthetic resin has a small amount of air permeability, when the above-mentioned prior art is applied to a lid for a wide-mouthed container in which an opening hole is formed in a large area, the container is long-term sealed. If it is stored for a certain period of time, there is a possibility that the contents may be deteriorated due to the moisture that has entered the container, or the odor of the contents may leak to the outside.

For this problem, it is conceivable that a non-breathable film is attached to the entire outer surface of the closing body to block the ventilation in and out of the wide-mouth container, but a gripping piece is attached to the outer surface of the closing body. In the case of the lid for a wide-mouthed container formed by projecting, this gripping piece interferes and the non-breathable film cannot be attached to the entire closure, so that the outer surface of the closure is impermeable. To attach the film, when forming the closure body integrally with the lid body, the closure body is formed without shaping the holding piece, and then the non-breathable film is attached to the outer surface of the closure body with an adhesive or the like. Then, it is necessary to attach a separately formed gripping piece to the outer surface of the closing body by means such as adhesive bonding or heat fusion.

However, as described above, in the method of attaching the holding piece separately formed from the closing body to the closing lid by means of adhesive or heat fusion, the attachment strength of the holding piece to the closing body is increased. Moreover, since the area of the base of the gripping piece is small and a strong force is applied to the base of the gripping piece when opening, the gripping piece is torn at the root part when opening, There is a possibility that there will be many accidents that make it impossible to open.

In addition, since the adhesive must be applied to the entire area of the blocker, the amount of the adhesive used increases, and the number of manufacturing steps increases, which makes the manufacturing time-consuming, which significantly increases the manufacturing cost. There is also a problem in doing it.

An object of the present invention is to make it possible to attach a non-breathable film to the outer surface of a synthetic resin closing body without causing these problems.

[Means for Solving the Problems]

In order to solve this problem, the present invention provides an opening hole in a lid made of a metal plate for the mouth of a wide-mouthed container, and the lid body is provided with a closing member made of synthetic resin having a gripping piece. In the method of manufacturing a lid body integrally formed so as to close the opening, a non-breathable film is attached to the surface of the lid body so as to close the opening hole, and then the lid body is closed. It is sandwiched between one mold having a body molding cavity and the other mold having a gripping piece molding cavity, and then a molten synthetic resin is injected into the closing body molding gait. did.

[Operation and effect of invention]

In this structure, the molten synthetic resin injected into the cavity for molding a closed body fills the cavity for molding a closed body while pressing the film against the other mold.

On the other hand, when the lid is sandwiched between the one mold and the other mold, the closing body molding cavity in one mold and the gripping piece molding cavity in the other mold are blocked by the film. However, the molten synthetic resin is injected into the cavity for molding the closed body with a high pressure, and while the film is pressed against the other mold with a strong force, it is strong toward the cavity for gripping piece molding. Since pressure is applied, the film is pierced by the molten synthetic resin at the entrance of the holding piece forming cavity, and the molten synthetic resin fills the holding piece forming cavity. A holding piece is integrally formed on the outer surface of the body.

Further, since the film is strongly pressed against the other mold by the molten synthetic resin, the film will be fused to the closing body, and the film will not be attached to the outer surface of the closing body without using an adhesive or the like. Will be firmly attached over the entire area.

Therefore, according to the present invention, a step of attaching a non-air-permeable film to the lid body is added before the lid body is sandwiched by the pair of molds to integrally form the closing body and the holding die. With this, the non-breathable film can be attached to the entire outer surface of the closure with the gripping piece being integrally molded, so it has both the safety before opening and the safety after opening. Moreover, there is an effect that a lid for a wide-mouthed container, which can surely prevent opening failure due to tearing of the gripping piece, can be manufactured at extremely low cost.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings (FIGS. 1 to 7). In the drawings, reference numeral 1 is a wide-mouthed container formed of an appropriate material such as metal or synthetic resin, and reference numeral 2 is the above-mentioned container. Each of the lid bodies made of a metal plate is provided with a downward U-shaped engaging portion 2a fitted in the mouth portion of the container 1, and the lid body 2 includes the lid body 2
A large-diameter opening hole 2b that is substantially concentric with the opening hole 2b.
The periphery of b is folded back inward, and the outer surface of the lid 2 facing the outside of the wide-mouthed container 1 is covered with an air-impermeable film 3 such as an aluminum foil so as to close the opening 2a. Adhere with.

As shown in FIG. 5, the film 3 is formed by coating or sticking or laminating a synthetic resin layer 3b such as polyethylene on both front and back surfaces of an aluminum foil 3a having a thickness capable of completely blocking ventilation. Although it is formed as a layer, it may be formed of only one sheet of aluminum foil or may be formed of only synthetic resin.

Then, the lid 2 is provided with a lower mold 7 provided with a closing body forming cavities 6 for forming a closing body 5 (see FIG. 7) for closing the opening 2b of the lid 2, and the closing body 5 The pull ring 8 as an example of a gripping piece is sandwiched by the upper die 10 having a pull ring molding cavity 9 for integrally molding on the outer surface of the lower mold 7 and the lower mold 7 is inserted into the closing body molding cavity 6.
A molten synthetic resin 12 such as polyethylene is injected at high pressure from a sprue 11 formed in the center of the.

Then, the molten synthetic resin 12 presses the film 3 against the upper mold 10 and fills the closing body forming cavity 6 to form the closing body 5.

On the other hand, when the lid body 2 is sandwiched by the upper and lower molds 7 and 10, the closing body molding cavity 6 and the pull ring molding cavity 9 are blocked by the film 3, but the molten synthetic resin 12 The pressure is high, and when the molten synthetic resin 12 fills the closing body forming cavity 6, a strong pressure acts on the pull ring forming cavity 9 in a state where the film 3 is pressed and fixed to the upper mold 10, The film 3 is pierced by the molten synthetic resin 12 at the entrance of the pull ring molding cavity 9 and the molten synthetic resin 12 fills the pull ring molding cavity 9, whereby the outer surface of the closing body 5 is filled. The pull ring 12 will be integrally molded.

Further, since the film 3 is strongly pressed against the lower surface of the upper mold 10 by the molten synthetic resin 12, the film 3 is firmly fixed to the entire outer surface of the closing body 5 without using an adhesive or the like. It will be. The edge portion 3a of the film 3 attached to the lid body 2 with the adhesive 4 is peeled off from the lid body 2 by the pressure of the molten synthetic resin 12 and pressed against the lower surface of the upper mold 10 to form the film 3 Is integrally formed in a state in which it is attached to the outer surface of the closing body 5.

In addition, on the upper surface of the lower mold 7, a projection 14 for forming a thin-walled weakening line 13 that cuts the closing body 5 is formed in an annular shape, and the pull ring molding cavity 9 in the upper mold 10 is It is formed by inserting a core 16 into a hole 15 formed in the upper mold 10 so as to be vertically slidable. By sliding the core 16 upward, the molded pull ring 8 can be removed from the mold. I am trying.

As shown in FIGS. 6 to 7, the lid body 2 manufactured in this manner is used by caulking the engaging portion 2a at the outer peripheral edge thereof to the mouth portion of the wide-mouthed container 1 or winding it. However, even when the closing body 5 is made of a low-permeability, inexpensive material such as low-density polyethylene, the non-breathing film 3 is attached to the entire outer surface of the closing body 5. Since the air inside and outside the container 1 is blocked, even if the container 1 is stored for a long time while being hermetically sealed, moisture may penetrate into the container and the contents may deteriorate, or the odor of the contents may leak to the outside. There is no such thing.

Then, to open the sealed container 1, the pull ring 8
Is pulled upward to cut the obstruction body 5 along the weakening line 13, and at the same time, the edge portion 3a of the film 3 is cut off.
It may be peeled off from the peripheral edge portion 5a and the portion surrounded by the weakening line 13 in the closure body 5 may be cut and cut.

In this case, since the pull ring 8 is formed integrally with the closing body 5, there is no problem that the pull ring 8 is cut off from the closing body 5 to make it impossible to open when opening, and since the closing body 5 is made of synthetic resin, There is no injury even if the outer peripheral edge of the cut off body 5 or a finger on the inner peripheral edge of the hole formed after opening is not injured, and the safety after opening can be improved.

During molding using the upper and lower molds 7 and 10, the molten synthetic resin 12 moves inside the closing body molding cavity 6 from the center to the end, so that the molten synthetic resin 12 When the film 3 breaks through the film 3, as shown in FIG. 4, the film 3 is subjected to a radial outward component force of the lid body 2, so that the film 3 is removed from the entrance portion of the pull ring forming cavity 9. The film mold 3b having the same area as the cross-sectional area of the entrance of the pull-ring molding cavity 9 is first broken at the center of the lid 2.
Is located on the outer peripheral portion of the lid 2 on the inner peripheral surface of the pull ring molding cavity 8. Therefore, after the die cutting, the entire film piece 3b is covered with the lid body on the outer peripheral surface of the root of the pull ring 12. It will be affixed to the outer side part of 2.

Then, the adhesive area between the peripheral edge 3a of the film 3 and the pull ring 8 increases, and when the pull ring 8 is pulled, the edge 3a of the film 3 is prevented from being broken at the root of the pull ring 8. It is possible to prevent a problem that only the portion of the edge portion 3a of the film 3 near the pull ring 8 is peeled off while being attached to the edge portion 5a of the closing body 5.

The above embodiment was applied to the method of manufacturing the lid body in which the closure body is cut and cut along the line of weakening, but the present invention, as shown in FIGS. It can be applied to a manufacturing method of the lid body 2 in which the closing body 5 is configured as a freely removable inner stopper and the film 3 is attached to the outer surface of the closing body 5, and in this case also, As shown in the figure, after the film 3 is attached to the lid body 2 so as to close the opening 2b, the film 3 is attached to the lower die 7 having the cavity 6 for forming the closing body and the pull ring forming cavity. 9
It is manufactured by injecting a molten synthetic resin from the sprue 11 of the lower mold 7 toward the closed body molding cavity 6 by sandwiching it with the upper mold 10 provided with.

The closure body 11 in FIGS. 8 to 9 is opened by cutting at the thin-walled weakening line 13 formed at the lower end thereof.

[Brief description of drawings]

The drawings show an embodiment of the present invention, FIG. 1 is a sectional view showing a state in which a film is attached to a lid, FIG. 2 is a sectional view showing a state where the lid is clamped by a mold, and FIG. Is a sectional view taken along line III-III in FIG. 2, FIG. 4 is a sectional view showing the flow of the molten synthetic resin, FIG. 5 is an enlarged sectional view of the film, and FIG. 6 is a state in which the lid is fitted to the container. FIG. 7 is a cross-sectional view showing an opened state, FIG. 8 is a plan view of a lid body having a closure body as an inner plug, and FIG. 9 is an enlarged cross-sectional view taken along line IX-IX of FIG. FIG. 10 is a view showing a manufacturing state of the lid body in FIGS. 8 and 9. 1 ... Wide-mouthed container, 2 ... Lid, 2b ... Hole, 3 ... Non-breathable film, 5 ... Closing body, 6 ... Closing body forming cavity, 7 ... Lower mold, 8 ... Picking Pull ring as an example of a holding piece, 9 ... Pull ring forming cavity, 10 ...
Upper mold, 12 ... Molten synthetic resin.

Claims (1)

[Claims] 1. A cover made of a metal plate for an opening of a wide-mouthed container is provided with an opening hole, and a closure member made of a synthetic resin having a holding piece is integrally formed with the cover body so as to close the opening hole. In the method for producing a lid body formed by mechanically molding, a non-air-permeable film is attached to the surface of the lid body so as to close the opening hole, and then the lid body is formed into the cavity for forming a closed body. It is sandwiched between one mold provided with and a mold having the holding piece forming cavity, and then a molten synthetic resin is injected into the closing body forming cavity. A method for manufacturing a lid for a wide-mouth container.