JPS5820430A - Production of narrow-mouthed container - Google Patents

Abstract

PURPOSE:To produce a seamless narrow-mouthed container speedily, by a method wherein a thin-walled metallic hollow core is placed in a metallic mold, green rubber is charged into a cavity formed between the core and the mold, and after vulcanizing and molding the rubber, the core is crushed and removed. CONSTITUTION:An aluminum-made spherical core 1 having a plate thickness of 0.2-2mm. is placed between an upper metallic mold 3 and a lower metallic mold 4. If required, compressed air is supplied into the hollow core 1 through a pressure hose 2. A green rubber compound is charged into the cavity 5 formed between the mold 3, 4 and the core 1, and is vulcanized by pressurizing and heating by press platens 6, 7 to produce a bladder article. Then, the bladder is taken out from the mold 3, 4, the interior of the core 1 is decompressed through the hose 2 to crush the core 1, and the crushed core is removed.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for manufacturing narrow neck containers, particularly seamless bladders.

The method for manufacturing a bladder with a narrow mouth compared to the body is to create a pair of molded products that are divided into two halves at the body without cutting them, and then glue the body of the molded products together. It is generally manufactured as a seamed bladder. This is because if the bladder is to be manufactured seamlessly, it is difficult to remove the molding core from the narrow mouth of the molded bladder.

On the other hand, as an example of a method for manufacturing a seamless bladder, a good method is to make a hollow core from thick-walled (lo my-8KL) aluminum, and after forming the bladder, dissolve the core in a caustic soda solution and deposit it from the bladder. Although known, this method has the following drawbacks.

1) It takes a very long time to melt the aluminum, so it takes too long to remove the core from the bladder. For example, it takes several days to melt an aluminum core with a thickness of I Omm.

2) It is necessary to maintain the concentration of caustic soda in the palm above a certain value.

3) The melting aluminum core has sharp protrusions that tend to damage the inner wall of the bladder, so it is necessary to constantly monitor and remove them.

4) Hydrogen gas is generated and must be removed.

The present invention provides a method for manufacturing a narrow container devised in view of the above, in which a thin-walled metal hollow core is placed in a mold, and an air gap between the core and the mold is filled with a hollow core. A narrow-mouth container is manufactured by filling vulcanized rubber and vulcanization molding, and then crushing the core inside the container to reduce its volume, and then taking it out from the mouth of the container. do. The present invention will be explained in detail with reference to the drawings.

FIG. 1 is a front sectional view of a press apparatus for explaining the method of manufacturing a bladder according to the present invention.

In the figure, ] is a thin-walled hollow spherical core made of metal;
It is formed by joining a bowl-shaped body 11 on the bottom side and a bowl-shaped body 12 on the mouth side having a cylindrical mouth part 121 at a large diameter part 13.

A large diameter portion 122 is provided in the middle of the hollow core 10 mouth portion 121.

2 is a pneumatic hose that is connected to the cylindrical mouth portion 121 and pressurizes the inside of the hollow core 1 . 3.4 is the upper and lower molds, and the large diameter part 122 of the hollow core 1 is held between the recesses 31 and 32 provided in the facing parts, and the hollow core 1 is held in a fixed position in the mold. Hold. Reference numeral 5 denotes a gap formed by the hollow core 1 and the molds 3 and 4. The cavity 5 is filled with a half preformed product that is preformed into a shape similar to a bladder product using an unvulcanized rubber compound and further divided into seven parts at the large diameter part,
Thereafter, the product is pressurized and heated and vulcanized using a press hot plate 6.7 to produce a bladder product. Pressurized air is supplied to the hollow core 1 through a pneumatic hose 2 in order to prevent the hollow core 1 from being crushed when pressurized. When the rubber material of the bladder is soft, or when liquid rubber is injected into the cavity 5 for molding, it is not necessarily necessary to supply pressurized air to the hollow core 1. "This": Take out the manufactured bladder from the molds 3 and 4, and then
Through this process, the pressure inside the hollow core 1 is reduced and the hollow core 1 is crushed to reduce its volume.The operation is then completed by taking out the shrunken core from the mouth of the bladder. Note that it is of course possible to simply crush the hollow core 1 without reducing the pressure.

FIG. 2 is a front sectional view of a press apparatus illustrating another embodiment of the present invention, in which a filler 17 is used in the hollow core. In the figure, 1' is a hollow core, which is formed in the same manner as in the embodiment shown in FIG.

However, the mouth portion 121' is simply cylindrical. 2' is a mandrel, and when the hollow core 1' is filled with a filling 8', the core 1' is moved into the molds 3/, 4/ against the weight of the filling 81.
It is meant to be held in place. The bladder opening side 21' of the mandrel 2' is thick enough to fit into the opening 121' of the hollow core 1', and is further provided with a large diameter collar 22'. Recesses 31' and 4 formed in the mating parts of molds 3' and 4/
]', the core l' is held at a predetermined position within the molds 3/4' by pinching the collar 22' of the mandrel. Reference numeral 5' denotes a void in the shape of a bladder product, which is composed of the hollow core 1' and the molds 3/ and 4/. The core 1' and the mold 3/
, 7-totes or blocks of unvulcanized rubber compound are loaded between 4/, and the molds 3' and 4' are pressed onto hot plates a/,
The product is molded into the shape of a bladder product by pressurizing at 7/7, and then heated at 130 to 180°C for 05 to 1 hour to complete the vulcanization molding of the bladder.

In this example, since the hollow core 1' is filled with a filler 8' for reinforcement, the unvulcanized rubber compound is
As in the embodiment shown, the core 1' and the mold 3' are made as a notebook or block without preforming.

Even if the core 1' is loaded between 4' and 4', the core 1' will not be deformed when pressurized, which is preferable. The conditions for the material for the filling 8' are as follows.

■It is possible to fix the positional relationship between the hollow core 1' and the mandrel 2' at room temperature. For example, in the case of a liquid, the mouth part 1 of the hollow core 1'
The heavy liquid must be supported by the recess 121' alone, but since the concave portion 121' is a thin metal body, its strength is weak, and it cannot be used because the core will sag under the weight of the liquid. However, once the molding before vulcanization is completed and it is broken, the unvulcanized rubber compound filled in the void 5' plays the role of supporting the core 1', so it will melt at the vulcanization temperature of 130 to 180°C. It can also be used for things. In this case, in order to prevent the filler 8' from flowing out from the core 1' during vulcanization,
It is necessary to perform sole treatment on 21'.

- After completion of vulcanization molding, the material can be extracted from the narrow opening of the hollow core 1'.

Specifically, these include easily fusible metals with a relatively low melting point, salts that can be dissolved in water, plastics that crack into small pieces due to stress cracks caused by solvents, or small glass or iron balls with lots of sand. Can be used. The bladder after vulcanization molding is placed in mold 3'.

4', first pull out the core rod 2' (to make it easier to pull out, the core rod 2' is made thinner towards the tip), then take out the stuffing 8' from the mouth 121' of the hollow core 1', and then After that, as in the case of FIG. 1, the hollow core 1' is reduced in size and taken out from the eye of the bladder, and the work is completed.

Aluminum, copper, and alloys thereof can be used as the metal material for the core. The thickness is preferably 02 to 2+ nm, particularly 05 to I mm, for handling purposes.

As detailed above, in the present invention, a thin-walled metal core is used, and after manufacturing the narrow-mouth container, the core is crushed to reduce its volume, and then taken out from the mouth of the container.
This method has the following advantages over the conventional method of using a thick-walled aluminum hollow core and melting it with a caustic soda solution.

■It is extremely easy to handle and the cores can be taken out of the narrow-mouthed container in a short period of time, so that narrow-mouthed containers can be manufactured reliably in a short period of time.

■Since the core is crushed as a single piece, sharp protrusions are often formed, so the inner wall of the container will not be damaged.

■It is safe and does not generate dangerous gases such as hydrogen gas.

■There is no need to use dangerous alkaline or acid solutions to dissolve the core.

It goes without saying that the present invention is useful not only in the production of bladders but also in the manufacture of containers whose mouths are narrower than their bodies.

[Brief explanation of drawings]

FIGS. 1 and 2 are front sectional views of an embodiment of a heat press apparatus for explaining the method for manufacturing a narrow-mouth container according to the present invention. In the figure, 1--thin metal hollow core, 2--hose, 3, 4- mold, 5- void, 6,
7- Press hot plate. Patent applicant: Dainichi Nippon Electric Cable Co., Ltd. Representative Director: Yukio Aoyama

Claims (1)

[Claims] A thin metal hollow core is placed in a mold, the gap between the core and the mold is filled with unvulcanized rubber, and after vulcanization molding is performed to manufacture a narrow-mouthed container, the inside of the container is 1. A method for producing a narrow container, characterized by crushing the particles to reduce their volume, and then taking them out from the mouth of the container.