JPS5914179Y2 - Container forming equipment - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to an apparatus for molding containers from a thermoplastic synthetic resin sheet using a plug-assisted molding method, and particularly relates to a container molding apparatus incorporating a plug of a novel structure.

The plug assist method stretches the softened sheet into the mold using a plug, and when it reaches the depth of drawing, compressed air is blown into it, and at the same time, the air inside the mold is removed by suction. This process allows the container to be shaped.

The plug built into this plug-assisted molding device is generally made of wood, synthetic resin, or metal, and when it comes to blowing out compressed air, the plug itself has no air permeability. There are plugs that eject from the periphery of the plug, and plugs that have several ventilation holes in the plug, but when using the former type of plug, the head of the plug comes out during continuous molding. Other problems include the fact that the temperature of the resin sheet rises in some parts, and depending on the type of resin sheet, it may adhere to the plug and become impossible to mold.
It is extremely difficult to mold containers with uniform wall thickness.

On the other hand, when using the latter type of plug, the portion of the sheet that is hit by the compressed air ejected from several ventilation holes stretches more than other sheet portions, resulting in uneven wall thickness. There are disadvantages such as the formation of a container and sometimes the formation of holes in the area where the air hits.

The container molding device according to the present invention can mold any desired container from any type of synthetic resin sheet without causing the above-mentioned problems. A thermoplastic synthetic resin sheet in a suitable state is introduced into a mold using a plug, and a container is molded under the control of blowing out compressed air and suctioning and removing air inside the mold. The plug is characterized in that it incorporates a plug made of blanket, ceramic or sintered metal, which has micro-vents through which compressed air can easily pass.

To explain the operating mechanism of the above-mentioned molding apparatus with reference to the drawings as an example, a thermoplastic synthetic resin sheet 2 in a moldable state is installed on the upper part of a mold 1, and the air inside the mold is sucked out by a suction mechanism 3. At the same time, the sheet 2 is introduced into the mold by means of a ventilation plug 6 provided at the head of the rod 5 guided in the chamber 4, and then compressed air is introduced into the mold through the plug 6.
Then, the sheet 2 is sequentially stretched into a mold under the control of the suction to form a container.

Accordingly, in the present invention, the material constituting the breathable plug may be one in which the plug frame is covered with a blanket, a powder ceramic molded into a breathable state, or a material formed into a breathable state. Processed sintered metal is used, and although the diameter of the vent hole of these plugs is not specified, a sufficient jetting effect can be achieved with a diameter of about several tens of microns, usually about 40 to 60 microns.

Since the container forming apparatus of the present invention has a built-in plug made of the above-mentioned material, the surface of the plug has a moderate roughness, which occurs when the sheet is introduced into the mold. This plays a role in preventing slippage between the plug surface and the sheet, and when the depth of drawing is reached, the sheet becomes a much thicker sheet compared to conventional plugs with slipperiness. This is a major factor in making it possible to uniformly mold the bottom edge of the container when molded from this sheet state.

Furthermore, when the compressed air C is ejected, the plug is appropriately cooled, and there is no need to worry about the plug's temperature rising or adhesion to the sheet even if continuous operation is performed.

In addition, since the plug (J) has micro ventilation holes over the entire surface, when compressed air is blown out, the air hits the sheet evenly, resulting in a container with a uniform wall thickness. can.

Such advantages are particularly advantageous when the lower wall of the paper cutlet is
When polyethylene is laminated using a method such as that described in Japanese Patent No. 0-31513, a remarkable effect can be exhibited when forming an extremely thin sheet.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a container forming apparatus according to the present invention.

Claims (1)

[Scope of utility model registration request] In an apparatus that introduces a thermoplastic synthetic resin sheet into a mold with a plug and forms a container under the control of blowing out compressed air and suctioning and removing air inside the mold, the plug 1. A container forming device comprising a blanket, ceramic, or sintered metal having microscopic ventilation holes that allow easy ventilation.