Process for rendering polyester hollow bodies gastight
AssigneeRhone-Poulenc Industries
InventorsGilbert Roullet, Pierre Legrand
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Abstract
The invention pertains to a process for producing bioriented polyester hollow bodies characterized by good gas and flavor tightness, wherein one wall of a preform is coated with an aqueous composition consisting of at least two incompatible polymers, one of which is a water soluble polyvinyl alcohol and the other, a polymer latex with low water sensitivity; the coating is dried and the preform is bidrawn-blown.
Claims12
In a process for producing bioriented polyester composite hollow bodies which includes the steps of making a preform, transferring the preform into a mold, bidrawing-blowing the preform under biorientation conditions to produce a hollow body, followed by cooling and removing the hollow body from the mold, the improvement comprising coating at least one wall of the preform with an aqueous composition composed of at least two imcompatible polymers, one of which is a polyvinyl alcohol in solution in water, and the other or others of which is a latex of relatively water insensitive polymers, in which the weight ratio of polyvinyl alcohol/latex polymer is between 0.4 and 3, to provide a two-phase system in which the polyvinyl alcohol solution forms a continuous phase and the water insensitive polymer is in the dispersed phase, drying the coating, followed by said bidrawing-blowing.
Dependencies are inferred from the claim text.