JPH09193961A - Cap with vent opening for plastic container - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a content in a container from oozing out by a method wherein two threaded members each having a hole communicating with a vent opening are provided at the center on the inner face of a cap, and a porous sheet is held between the two members. SOLUTION: Screw threads 3 to be screwed on a mouth of a container main body are formed on the inner face of a sidewall of a cap 1 and protrusions 4 are formed on the outer face of the sidewall to easily hold the cap 1. An upper threaded member 8 with a hole 7 leading to a vent opening 2 is projected from the center of the inner face of the cap 1, and a lower threaded member 9 to be screwed on the upper threaded member 8 has a hole similarly and a sheet mount 10 to hold an airpermeable sheet 6 between the downside of the upper threaded member 8 and the upside of the lower threaded member 9. The air-permeable sheet 6 is placed on the sheet mount 10 and fixed by holding it between the upper threaded member 8 and the lower threaded member 9. Thereby, a porous membrane of the air-permeable sheet itself is prevented from breaking through fusing in the case the air-permeable sheet is fixed by thermal fusion bonding.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cap having a ceiling plate provided with a vent for covering a spout of a plastic container filled with a liquid, a viscous substance or a powder, and particularly to a gas generated from the contents in the container to the outside. A cap having a vent for a plastic container that can escape.

Conventionally, as a container for a liquid, a viscous body, a powder body, or the like having fluidity, for example, a container in which an inner bag in which ends of opposite ridges of a cube are joined at the center of a side wall is contained in an outer box (for example, A plastic container in which a peripheral edge portion of a plastic film or sheet is heat-sealed is widely used, including a registered trademark Cubitener. However, some of these contents may generate gas during storage, or may require the air in and out of the container to be transported in order to carry a place having a pressure difference. For this purpose, conventionally, a ceiling plate of a cap of this type of container is provided with a vent, and a porous sheet is adhered to prevent leakage of liquid or contamination from the outside through the vent. (See, for example, Japanese Utility Model Publication No. 56-53012). A conventionally used cap with a vent is shown in FIG. That is, a vent hole 2 is provided in the center of the cap, and a screw portion 3 that is screwed into the spout of the container body is formed on the inner circumference of the peripheral edge of the cap, and the outer circumference thereof is convex so that the cap can be easily rotated by hand. The part 4 is formed. A projection piece 5 is provided on the inner surface of the cap for preventing liquid leakage from the threaded portion, and a porous sheet 6 having air permeability is heat-sealed to the vent hole 2 to prevent dust and the like from the outside. Prevents intrusion.

However, in such a conventional cap,
Since the air-permeable porous sheet 6 is heat-sealed to the inner surface of the cap, the porous film of the sheet itself is melted and the original function is deteriorated. Has a drawback in that it comes into contact with the sheet to wet the sheet and cause liquid leakage.

[0004]

Therefore, the present inventor has improved the above-mentioned drawbacks of the conventional caps, prevented the fusing of the porous membrane of the breathable sheet provided on the inner surface of the cap, and the liquid from the sheet. As a result of various studies to prevent the exudation of the gas, an upper threaded part and a lower threaded part having a hole communicating with the vent hole for venting are formed in the center of the inner surface of the cap with a threaded part consisting of two members. The present invention has been completed by finding that the above-mentioned problems can be solved by providing a sheet between the lower surface of the upper screwing portion and the upper surface of the lower screwing portion and sandwiching the sheet between them to fix the sheet. Accordingly, an object of the present invention is to provide a cap having a vent for a plastic container, which prevents the contents in the container from seeping out.

[0005]

DISCLOSURE OF THE INVENTION The gist of the present invention is a cap having a vent for a plastic container having a vent in the center and a threaded portion for screwing into a spout of the container body on its inner periphery. , A central portion of the inner surface of the cap is provided with a screwing portion formed of two members that are screwed with each other and provided with a hole communicating with the vent, and the porous sheet is provided between the two members of the screwing portion. And a sheet is fixed by sandwiching the sheet by two members, and the cap has a vent hole of a plastic container.

The present invention will be described in detail. The plastic container in the present invention may be any synthetic resin container having a screw-type spout, and is preferably an inner bag of a bag-in-box formed by fusing the periphery of a plastic film or sheet. This container is a single bag, a double bag or the like, or a bag in which diagonal lines on the side surfaces of a rectangular parallelepiped or a cube and their opposing ridge lines are joined (for example, registered trademark Cubitener), concentrated juice, foods such as vinegar and adhesives,
It is used as a plastic container for containing industrial chemicals such as sodium hypochlorite, hydrazine or photographic developer. The material for this plastic container is a single layer film such as polyethylene or polypropylene, or polyethylene, polypropylene or ethylene.
A heat-adhesive film such as vinyl acetate, a film having a toughness such as nylon or polyester in the intermediate layer, or an ethylene-polyvinyl alcohol film: or a laminated film formed of a film having a gas barrier property such as an aluminum foil may be used. Especially, linear low density polyethylene (LLDPE) is preferable. On the upper surface of such a plastic container, there is provided a plastic spout having a threaded portion on the outer circumference.

In the present invention, a plastic cap provided at the spout and screwed into a screw will be described in detail with reference to the drawings. FIG. 1 is a sectional view of a cap 1 according to the present invention. The cap 1 has a vent hole 2 in the center, a screw part to be screwed into the spout of the plastic container body on the inner surface of the outer periphery of the cap, and a convex part 4 on the outer surface of the outer periphery of the cap for easy gripping. To provide. According to the present invention, in such a cap, an upper screwing portion 8 having a hole portion 7 communicating with the vent 2 is provided on the inner surface of the central portion of the cap, and the upper screwing portion 8 is screwed to the upper screwing portion 8. A lower threaded portion 9 having a hole 7 is provided. Upper screw part 8
A breathable sheet 6 between the lower surface of the sheet and the upper surface of the lower threaded portion 9
A seat mounting portion 10 for mounting a seat is provided. The breathable sheet 6 is arranged in the seat mounting portion 10, and is fixed by sandwiching the upper screwing portion 8 and the lower screwing portion 9.

[0008]

EXAMPLES Next, the cap of the present invention will be specifically described by way of examples. Approximately 4 mm in diameter at the center of the ceiling plate of low density linear polyethylene (LLDPE) with an outer diameter of 48 mm
A vent hole is provided, and an upper screw portion having an outer diameter of about 10 mm and a height of about 5 mm, which has a spiral on the outer peripheral surface, is projectingly provided at the center of the inner surface of the cap. A through hole is provided in the central portion of the upper screwed portion so as to coincide with the vent hole of the cap, and a recessed portion is provided on the lower peripheral surface of the upper screwed portion. A lower screw portion that is screwed to the upper screw portion is provided, and a spiral is provided on the inner peripheral surface of the lower screw portion so as to be screwed to the spiral portion provided on the outer peripheral surface of the upper screw portion. Further, a through hole that matches the through hole of the upper threaded portion is provided below it. The upper peripheral surface of the lower threaded portion is provided with a ridge that matches the recessed section of the lower peripheral surface of the upper threaded portion. The height of the lower threaded portion is about 10 mm, and the porous sheet is held at a position about 5 mm from the inner surface of the cap in between. When using such a cap, the seat is placed between the upper screwed portion and the lower screwed portion, and the upper screwed portion and the lower screwed portion are screwed together. It is securely sandwiched by the concave streak portion on the lower peripheral surface and the convex streak portion on the lower threaded portion.

[0009]

As described above, according to the present invention, the cap is provided with the screwing portion including the upper screwing portion and the lower screwing portion at the center of the inner surface, and the breathable sheet is provided between the screwing portion and the upper screwing portion. Since it is fixed by sandwiching it with the lower threaded portion, it is possible to prevent melting of the porous membrane of the breathable sheet itself that occurs when fixing by a conventional heat fusion method, Since the area of the member opening on the liquid surface side of the joining portion can be reduced, it is possible to prevent liquid leakage due to contact of liquid. Furthermore, since a cylindrical space can be provided directly below the breathable sheet, contact between the liquid surface of the contents and the breathable sheet can be suppressed, and the space from the sheet surface to the top surface of the cap ( By providing the height, it is possible to obtain an effect such that the time for the liquid to seep out to the upper surface (outside) of the sheet can be lengthened.

[Brief description of the drawings]

FIG. 1 is a sectional view of a cap according to the present invention.

FIG. 2 is a cross-sectional view of a conventional cap.

[Explanation of symbols]

1 Cap 2 Vent hole 3 Screw part 4 Convex part 5 Projection piece 6 Porous sheet 7 Hole part 8 Upper screw part 9 Lower screw part 10 Seat mounting part

Claims (1)

[Claims] 1. A cap having a vent for a plastic container in which a vent is provided in a central portion and a screw portion which is screwed into a spout of a container main body is provided on an inner periphery thereof, wherein the vent is provided in a central portion of an inner surface of the cap. A screwing portion formed of two members screwed with each other having a hole communicating with the mouth is provided, and a porous sheet is arranged between the two members of the screwing portion and sandwiched by the two members. A cap having a vent for a plastic container, characterized in that the sheet is fixed thereby.