JP3319809B2 - Closed hollow container and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a hermetically sealed hollow container used as a container for foods, pharmaceuticals, cosmetics, industrial chemicals and the like, and a method for producing the same.

[0002]

2. Description of the Related Art A closed hollow container of this kind is one in which the hollow container is hermetically sealed before the contents are stored to prevent contamination of bacteria and foreign substances. The method (b) and the like are known.

(A) After a hollow container is manufactured by ordinary blow molding, a blow hole formed in the hollow container is covered with a lid and sealed by welding.

(B) As shown in FIG. 5, at the time of blow molding, a bulging portion 101 connected to the mouth of the hollow container is formed, and then, after the nozzle 106 is pulled out, the molten resin 103 in the resin reservoir is paired. The blow holes are closed by forming a welded portion 102 by pressing with the crimping rods 104 and 105 (see Japanese Patent Publication No. 52-45341).

[0005]

However, in the prior arts described above, the portions where the blow holes are closed are exposed, and when an external impact is applied during transportation or the like, the portions that close the blow holes are damaged. There is a problem. Also,
In (b), it is necessary to form a welded part during melting of the parison at the time of blow molding, so that the welding may become insufficient as the cooling of the parison progresses.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and completely closes a blowing hole of a closed hollow container and has no possibility of externally applying an impact to the closed portion. An object is to realize a hollow container and a method for manufacturing the same.

[0007]

In order to achieve the above object, a closed hollow container according to the present invention comprises a hollow container body, an opening connected to the hollow container body, and an opening at the opening. A cylindrical bulging portion connected to a portion of the bulging portion,
A recess formed by recessing a part of the side wall toward the interior of the room, and a blowing hole formed in a bottom wall of the recess are closed by a closing resin.

Further, the method for producing a closed hollow container according to the present invention comprises a hollow container main body, a mouth connected to the hollow container main body, and a cylindrical expansion connected to a portion to be an opening of the mouth. Using a split mold having a cavity for forming a recess formed by recessing a part of the side wall of the protruding part and the bulging part toward the indoor side, disposing a molten parison between the opened molds. and it closed the later type, after the mold closed by the recess is formed, and blow molding along the cavity then pressing the pressurized fluid from the bottom wall of the recess, the bottom wall by press fitting of the pressurized fluid The closing hole is closed by a closing resin.

Further, when forming the concave portion by closing the mold, it is effective if the portion serving as the bottom wall of the concave portion is vacuum-sucked and brought into close contact with the cavity surface.

[0010] The closing resin that closes the blowing hole imparts fluidity by heating and melting the resin to close the blowing hole. The resin is not only a heat-fusible resin but also a hollow container. Resin near the concave portion is also possible.

[0011]

[Action] is provided with recess portions of the side wall of the cylindrical bulged portion in a state where the recessed toward the cabin, blow holes are formed in the bottom wall of the recess. For this reason, the portion where the blowing hole is closed by the closing resin is located in the recess and is not exposed, and there is no possibility that an external impact is directly applied as long as the head of the closing resin exists in the recess.

[0012]

An embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an elevational view showing a first embodiment of a closed hollow container according to the present invention, in which a main part is shown in a partial cross section.
FIG. 2 is a sectional view taken along line AA in FIG. 1.

The closed hollow container is a hollow container body (hereinafter, referred to as a hollow container body).
It is called "container body". 1), a mouth portion 2 connected to the container body 1, and a tubular bulge portion 3 connected to a cutting portion 5 which is a portion to be an opening of the mouth portion 2. 3 of the side wall of the
A part of the recess 4 is formed by recessing part of the recess toward the indoor side, and a blow hole 7 formed in a bottom wall 4a, which is one surface of the recess 4, is closed and sealed by a rivet-shaped closing resin 6. .

In this embodiment, a blow hole 7 is formed in the bottom wall 4a of the recess 4.
Is formed, and since the blowing hole 7 is closed by the closing resin 6, the entire portion closed by the closing resin 6 is surrounded by the peripheral wall 4 b of the concave portion 4, so that an external impact is directly applied. There is no fear.

Here, a manufacturing method for manufacturing the hermetically sealed hollow container of the first embodiment will be described.

First, the mold used will be described.
As shown in FIG. 3, the mold is of a split type, and has one mold 11 and the other mold in which a core mold 13 whose tip projects toward one mold 11 is provided. When the mold is closed, when the mold is closed, the container body 1, the mouth portion 2 having a threaded portion 2a on the outer peripheral surface provided continuously with the container body 1, and the cutting portion 5 which is the opening portion of the mouth portion 2 are formed. It is configured such that a continuous cylindrical bulging portion 3 and a cavity 18 for regulating the outer surface of the concave portion 4 in which a part of the side wall of the bulging portion 3 is recessed toward the room side are formed. The core mold 13 has a nozzle insertion hole 13a penetrating in the axial direction, and a nozzle 14 communicating with a pressurized fluid generation source such as pressurized air (not shown) is fitted into the nozzle insertion hole 13a. Also, the other mold 12
Is a vacuum suction hole 1 having one end opened on the inner peripheral surface of the nozzle insertion hole 13a and the other end communicating with a vacuum source (not shown).
A seal ring is provided between the inner peripheral surface of the nozzle insertion hole 13 a and the core mold 13 and between the mold 12 and the outer peripheral surface of the core mold 13 on the side opposite to the cavity of the vacuum suction hole 15. It is devised so that airtightness is maintained by interposing 16, 16.

Next, the steps will be described.

After the molds 11 and 12 are opened, a molten parison made of a thermoplastic resin is extruded from an extrusion head of an extruder (not shown) and is disposed between the molds 11 and 12, and the mold is closed. When the mold is closed, the parison is held between the molds 11 and 12 while performing vacuum suction through the vacuum suction holes 15. As a result, the concave portion 4 is formed in a portion serving as a side wall of the bulging portion 3. Then, the portion which becomes the bottom wall of the concave portion 4 by vacuum suction is brought into close contact with the outer peripheral surface of the distal end portion of the core mold 13 as the cavity surface, and the opening of the blow hole 7 described later is formed with high precision.

Then, when a pressurized fluid such as pressurized air is supplied through the nozzle 14, the pressure causes the blow hole 7 to be opened at the bottom wall of the recess 4 and the pressurized fluid is introduced into the parison. Then, it is expanded along the cavity 18.
At this time, the parison in the part of the blow hole 7 opened by the pressurized fluid is blown off, but adheres to the inner surface of the opposed bulging part 3 because it is in a molten state, and is mixed into the mouth part 2 and the container body 1. Never.

Next, a second embodiment of the closed hollow container of the present invention will be described.

FIG. 4 shows a second embodiment, and is a sectional view of a portion similar to FIG.

In this embodiment, a cylindrical folded portion 24c is formed on the bottom wall 24a of the recess 24 so as to project outward.
The blowing hole 27 formed in the top wall is closed by a closing resin 26. In each step of the manufacturing method, the shape of the tip of the core mold provided in the other mold is the same as that of FIG. Only the difference from the case of the first embodiment shown in FIG.

In this embodiment, the rivet-shaped closing resin 26 is used.
Since the shaft portion can be formed longer, the sealing performance and mechanical strength of the closed portion can be maintained even in the case of a thinner wall as compared with the first embodiment.

In the present invention, the inner peripheral surface at the tip of the nozzle is tapered to reduce the thickness of the parison at this portion, thereby reducing the amount of parison blown off. Can be.

[0026]

Since the present invention is configured as described above, the following effects can be obtained.

The portion closed by the closing resin is not directly exposed because it is surrounded by the peripheral wall of the concave portion, so that there is no possibility that an external impact is applied. And the blow hole can be completely closed.

[Brief description of the drawings]

FIG. 1 is an elevational view showing a first embodiment of a closed hollow container of the present invention, and showing a main part in a partial cross section.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view of a main part of a mold, showing one step of a method of manufacturing the closed hollow container shown in FIG.

FIG. 4 shows a second embodiment of the closed hollow container of the present invention, and is a cross-sectional view of a portion similar to FIG.

FIG. 5 shows a manufacturing process of a conventional closed hollow container, and (A)
FIG. 2 is a cross-sectional view of a main part of a mold, and FIG. 2B is a cross-sectional view of a main part of a closed hollow container.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Container main body 2 Mouth part 2a Screw part 3,23 Swelling part 4,24 Concave part 4a, 24a Bottom wall 4b, 24b Peripheral wall 5 Cutting part 6,26 Closure resin 7,27 Blow hole 11,12 Die 13 Core die Mold 13a Nozzle insertion hole 14 Nozzle 15 Vacuum suction hole 16, 17 Seal ring

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) B29C 49/00 B29C 49/04 B29C 49/24 B65D 1/00 B65D 1/02 B65D 1/09

Claims (3)

(57) [Claims] 1. A hollow container main body, a mouth portion connected to the hollow container body, and a tubular bulging portion connected to a portion to be an opening of the mouth portion, wherein the bulging portion is provided. A closed hollow container, characterized in that a concave portion formed by recessing a part of the side wall toward the inside of the room and a blowing hole formed in a bottom wall of the concave portion are closed with a closing resin. 2. A hollow container main body, a mouth connected to the hollow container main body, and a portion connected to an opening of the mouth.
The cylindrical bulging part and a part of the side wall of the bulging part are directed to the indoor side.
Using a divided mold having a cavity for forming a recessed recess, closing the mold after disposing the melted parison between the opened molds, forming the recess by closing the mold, Then, after pressurized fluid is press-fitted from the bottom wall of the concave portion and blow-molded along the cavity, the blowing hole opened in the bottom wall by press-fitting the pressurized fluid is closed by a closing resin. Of producing a closed hollow container. 3. The method for producing a closed hollow container according to claim 2, wherein, when forming the concave portion by closing the mold, a portion serving as a bottom wall of the concave portion is brought into close contact with the cavity surface by vacuum suction.