Process for producing plastic hollow bodies
AssigneeKautex Textron GmbH & Co. KG
InventorJuergen Moitzheim
Life of this patent
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Abstract
In a process and apparatus for producing hollow bodies from plastic material which are at least partially filled with foam, firstly a preform is expanded in a blow molding mold by an increased internal pressure to form a hollow body which is then at least partially filled with foam plastic beads. The compressed beads are introduced into the expanded hollow body while still within the mold, under a pressure which is higher than the pressure obtaining in the hollow body. The beads in the hollow body experience a relief of pressure which results in the increase in volume of the beads and which provides for at least very substantial filling with a foam of at least a delimited part of the volume in the hollow body.
Claims4
A process for producing plastic material bodies at least partially filled with foam comprising the steps of:
- expanding a plastic preform in a blow molding mold using an increased internal pressure to form a hollow body;
- providing beads of foamed plastic and compressing the beads under a first pressure to effect a reduction of bead volume in a compressed condition;
- introducing the beads in the compressed condition into at least one delimited part of the expanded hollow body while the hollow body is still in the mold with a second pressure existing inside the hollow body, wherein the first pressure is greater than the second pressure;
- and,
- relieving the second pressure in the hollow body, such that the beads experience a relief of pressure resulting in an increase in the bead volume within the hollow body to provide as complete a filling as possible of the at least one delimited part of the hollow body,
- wherein the introducing step and the relieving step are carried out in such a manner that the beads do not join together.
Dependencies are inferred from the claim text.