Blow molding and fluorination process for the production of hollow bodies from thermoplastic materials and products so made
AssigneeKautex-Werke Reinold Hagen GmbH
InventorUlrich Karsch
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Abstract
In a process for the production of a hollow body such as a fuel tank from thermoplastic material, the wall thereof is subjected to a two-step treatment to influence the permeation properties of the material. In the first treatment step the wall is subjected to the action of a gas mixture containing fluorine and oxygen while in the second treatment step the wall is subjected to the action of a gas mixture which contains fluorine but is oxygen-free.
Claims20
A process for the production of a hollow body from a thermoplastic synthetic polymer by blow molding and fluorination, comprising expanding a preform within a blow molding mold using a gaseous pressure agent until a hollow body resulting from the expanded preform bears against the internal contour of the mold, and subjecting an internal wall surface of the resulting hollow body to a fluorination treatment to make the wall surface less permeable in relation to at least one substance, said treatment comprising a first treatment step in which the wall surface is treated with a gas mixture which contains fluorine and oxygen and thereafter a second treatment step in which the wall surface is treated with a gas mixture which contains fluorine but no oxygen.
Dependencies are inferred from the claim text.