Method for injection molding of hollow articles of plastic material
AssigneeITW Automotive Products GmbH & Co. KG
InventorElmar Fries
Life of this patent
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Abstract
An injection molding method to manufacture hollow plastic parts, whereby at least one plastic part's hollow is shaped by evacuating an internal portion of the flowable material of an injection mold's cavity (12) using a pressurized gas and a gate of said mold (10) and thereupon the molded article's aperture so made shall be sealed off, characterized in that, following said flowable material's being removed from a blind duct (24) into a gate branched to it and after being partly forced back into said hollow, said molded article shall be elected from the injection mold (10).
Claims10
A method for injection molding of a hollow part of plastic material, whereby a cavity of the hollow part is shaped by evacuating an internal portion of the flowable plastic material in a cavity of an injection mold by using pressurized gas whereby the material is pressed into a runner duct of the mold,
- characterized in that
- after pressing the material into the runner duct, the material is partially forced back into the cavity of the hollow part by means of a power actuated plunger located in a blind channel which is connected to the runner duct.
An injection mould for the manufacture of an article having at least one hollow space, comprising
- a preferably split injection tool having at least one cavity, the cavity being connected to a casting channel through which plasticized mass is pressed into the mould cavity, and
- a gas passage through which gas under pressure is supplied into the mould cavity to remove an inner portion of the plasticized mass from the mould cavity through the casting channel,
- characterized in that
- adjacent to the mould cavity, a blind channel is formed connected to the casting channel, the bottom of the blind channel being formed by a plunger within the blind channel and the plunger being actuable by power means to move the plunger towards the casting channel.
Dependencies are inferred from the claim text.