Abstract: The present invention discloses an improved process for producing plastic containers with excellent resistance to permeation by solvents such as hydrocarbons, hydrocarbon fuels, and hydrocarbon fuels with organic additives including lower alkanols and ethers consistently and reliably. The process is related to a multi-step treatment of plastic containers in a controlled manner with fluorine containing gases while blow molding them. In the process of the present invention, a parison is formed from a pre-heated thermoplastic material, expanded within a closed mold by means of an inflating gas for conforming the parison to the shape of the mold, and subjected to multiple fluorination treatment steps to effect fluorination of the interior surface of the parison. In the first step of the multi-step fluorination treatment the parison is pressurized with a reactive gas containing from about 0.05 to about 0.

Abstract: A multi-step blow molding process for producing fuel containers having excellent resistance to permeation by hydrocarbon fuels and organic fuel additives such as lower alkanols and ethers. In blow molding, a parison is formed from a thermoplastic material, expanded within a closed mold by means of an inflating gas for conforming the parison to the shape of the mold and fluorinated under conditions sufficient to effect surface fluorination of the interior of the parison. The parison is evacuated and the article recovered. The improvement in the blow molding operation comprises pressurizing the parison with a reactive fluorine containing gas containing from 0.1 to 1% fluorine by volume while the parison is at a temperature above its self supporting temperature and for a time sufficient to effect fluorination of the interior surface of the parison.