a process for the production of dish - shaped moldings or hollow bodies of thermoplastic material comprises the step of producing an at least approximately tubular preform by the extrusion of thermoplastic material . the preform is axially divided to form at least one single - layer web of material which is removed from the extrusion head by being engaged by means of a manipulator which spreads and / or straightens the web transversely with respect to the extrusion direction . the web is then transferred to a molding tool by a manipulator for it to be put into its final form in its first heat in the molding tool .