Method for producing containers
AssigneePlm AB
InventorClaes T. Nilsson
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Abstract
A method for providing a container with one or more layers of barrier material during the production of the container from a thermoplastic. A preform (10) is stretched in its axial direction, generally an amount corresponding to the total axial stretching required for conversion of the preform to a container, after which the stretched preform (11, 13) is provided with one or more barrier layers (12, 14), and the preform is then heated and converted to a container. In one embodiment, the axially stretched preform (15) is produced by assembling axially stretched part-preforms (13a,b) covered with one or more barrier layers. The combined preform is then converted to a container.
Claims10
A method for producing a barrier-coated container of a thermoplastic material from a preform, said method comprising stretching a preform of amorphous thermoplastic material axially while reducing the wall thickness of the preform to form an axially stretched preform having monoaxially oriented crystallinity, applying a barrier layer on the axially stretched preform, heating the thus coated preform to a molding temperature therefor and circumferentially expanding the axially stretched and coated preform to form the barrier-coated container, wherein said axial stretching represents the total axial stretching of the preform and said barrier layer only undergoes circumferential expansion and corresponding reduction in thickness.
Dependencies are inferred from the claim text.