Barrier-coated tube of biaxially stretched thermoplastic material having a monoaxially stretched barrier coating thereon

摘要

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. By means of the invention, it is possible to reduce the thickness of the barrier layers at the time of their application, which considerably simplifies the latter.