EP-4737094-A1 - CONTAINER MANUFACTURING METHOD, MOLD, AND CONTAINER

Abstract

A frame mold including an upper mold and a lower mold provided with a mold core (20) is used, a tubular body film (10) made of plastic film laminate is attached to the mold core (20), a molten resin material is injected into the frame mold by an insert injection molding means to form a bottom member in an upper end portion of the body film (10) and to form a frame member in a lower end portion of the body film (10), a concave portion (24) extending in an upward/downward direction is formed in at least upper and lower end portions of an attachment surface of the mold core (20) for the body film (10), a convex portion (25) is formed in a position of the frame mold corresponding to the concave portion (24), and the bottom member and the frame member are formed in a state in which the body film (10) is sandwiched between the concave portion (24) and the convex portion (25).

Inventors

• ICHIKAWA TORU
• SHINOHARA TOMONARI

Assignees

• Hosokawa Yoko Co., Ltd.

Dates

Publication Date

20260506

Application Date

20240628

Claims (11)

1. A container-manufacturing method, comprising: using a frame mold including an upper mold and a lower mold provided with a mold core; attaching a tubular body film to the mold core; injecting a molten resin material into the frame mold by an insert injection molding means to form an upper molded part in an upper end portion of the body film and to form a lower molded part in a lower end portion of the body film, wherein a concave portion extending in an upward/downward direction is formed in at least upper and lower end portions of an attachment surface of the mold core for the body film, a convex portion is formed in a position of the frame mold corresponding to the concave portion, and the upper molded part and the lower molded part are formed in a state in which the body film is sandwiched between the concave portion and the convex portion.
2. The container-manufacturing method according to claim 1, wherein the concave portion is provided on an entire length of the mold core in the upward/downward direction.
3. The container-manufacturing method according to claim 1, wherein a mold surface in which the convex portion is formed moves in a direction orthogonal to the attachment surface.
4. The container-manufacturing method according to claim 1, wherein the mold core, whose lateral cross section is rectangular, is used.
5. The container-manufacturing method according to claim 4, wherein the concave portion is formed in each of two side surface portions located to be opposite to each other of four attachment surfaces, the attachment surface including the four attachment surfaces.
6. The container-manufacturing method according to claim 4, wherein the concave portion is formed in each of four attachment surfaces, the attachment surface including the four attachment surfaces.
7. The container-manufacturing method according to claim 1, wherein the upper molded part is formed in a state in which a bottom surface film is placed on a top surface of the mold core.
8. The container-manufacturing method according to claim 1, wherein a connecting portion connecting two portions of the body film together in a circumferential direction, and the concave portion are disposed in different positions in the circumferential direction.
9. A mold, comprising: a frame mold including an upper mold and a lower mold, wherein the lower mold is provided with a mold core to which a tubular body film is attached, the frame mold is provided with a resin injection part configured to inject a molten resin material by an insert injection molding means thereinto to form an upper molded part in an upper end portion of the body film and to form a lower molded part in a lower end portion of the body film, a concave portion extending in an upward/downward direction is formed in at least upper and lower end portions of an attachment surface of the mold core for the body film, a convex portion is formed in a position of the frame mold corresponding to the concave portion, and the mold is configured to form the upper molded part and the lower molded part in a state in which the body film is sandwiched between the concave portion and the convex portion.
10. A container manufactured by the container-manufacturing method according to any one of claims 1 to 8.
11. A container manufactured using the mold according to claim 9.

Description

TECHNICAL FIELD The present invention relates to a container-manufacturing method, a mold, and a container. Priority is claimed on Japanese Patent Application No. 2023-108395, filed June 30, 2023, the content of which is incorporated herein by reference. BACKGROUND ART In the related art, for example, as containers for containing contents, for which preservability is important, such as powdered milk for infants, powdered coffee, coffee beans, and powdered supplements, tubular plastic containers have been used, which can be reduced in volume after use, are highly disposable, and are made of thin plastic film laminate. In such a plastic container, a method of inserting a body film into an injection mold when molding the plastic container by a film-inserting method for the mold is known (for example, see Patent Document 1). That is, the plastic container includes a body part having a tubular shape with bottom and molded of a plastic film into a tubular shape, and molded parts coupled to one end side and another end side of body part by an insert injection molding means. Then, Patent Document 1 discloses a method of pushing a laminated tubular member to a tip portion of a mold core, which is a molding core, guiding the laminated tubular member toward a base end of the mold core while injecting a gas to a space between the mold core and the laminated tubular member, and attaching the laminated tubular member to an outer surface of the mold core. Citation List Patent Document Patent Document 1: Japanese Unexamined Patent Application, First Publication No. 2011-189682 SUMMARY OF INVENTION Technical Problem However, the plastic container in the related art has the following problems. In the plastic container-manufacturing method in the related art disclosed in Patent Document 1, the perimeter of the laminated tubular member (body film), which is made of plastic laminate film and is to be attached (inserted) to the mold core, is the same as the perimeter of the mold core, so it may be difficult to attach the laminated tubular member to the mold core. Therefore, if the perimeter of the body film is increased (lengthened) to make it easier to attach the body film to the mold, when molds are closed, the extra length of the perimeter of the body film that closely contacts the mold core will be gathered between the molds, causing wrinkles by pinching the extra length portion of the body film between the molds, so there are a quality issue and a room for improvement. The present invention has been made in consideration of the above-described circumstances, and an object thereof is to provide a container-manufacturing method, a mold, and a container that allow a body film to be easily attached to a mold core, and prevent the film from being pinched during mold closure to suppress deterioration in appearance quality. Aspect 1 of a container-manufacturing method of the present invention includes: using a frame mold including an upper mold and a lower mold provided with a mold core; attaching a tubular body film to the mold core; injecting a molten resin material into the frame mold by an insert injection molding means to form an upper molded part in an upper end portion of the body film and to form a lower molded part in a lower end portion of the body film, in which a concave portion extending in an upward/downward direction is formed in at least upper and lower end portions of an attachment surface of the mold core for the body film, a convex portion is formed in a position of the frame mold corresponding to the concave portion, and the upper molded part and the lower molded part are formed in a state in which the body film is sandwiched between the concave portion and the convex portion. According to Aspect 1 of the container-manufacturing method of the present invention, since the perimeter of the body film is larger than the perimeter of the mold core excluding the concave portion, the body film can be easily attached to the mold core. In addition, when the molds are to be closed, the concave portion of the mold core and the convex portion on the frame mold side fit together through the body film, which allows the body film to closely contact the concave portion, causes no excess portion of the body film in the circumferential direction, and allows the entire body film to closely contact the mold core. Therefore, it is possible to prevent the body film from being pinched during mold closure as in the related art, to form the upper and lower molded parts in the upper and lower end portions of the body film with high quality, and to suppress deterioration in the appearance quality of the container. Aspect 2 of the present invention is that in the container-manufacturing method of Aspect 1, the concave portion is provided on an entire length of the mold core in the upward/downward direction. In this case, the body film of the formed container is easily removed from the mold core in the upward/downward direction. Therefore,