PROCEDE POUR OBTENIR UNE PREFORME CONSTITUEE PAR TROIS COUCHES POUR LE FACONNAGE PAR SOUFFLAGE D'UN CORPS CREUX EN MATIERE THERMOPLASTIQUE

摘要

A method is disclosed for making a three layered parison for blow molding a biaxially oriented hollow article of thermoplastic material. One end portion of an extruded tubular body is heated to welding temperature and closed to a bottom by a forming step. The central layer of the multilayered body is removed from part of the end portion before the forming step takes place to insure that the central barrier layer of the body allows for an intimate welding together of the inner and outer layer. A similar operation is used in making the finish portion of a container at the opposite end of the tubular body.