PROCESS AND APPARATUS FOR THE PRODUCTION OF A HOLLOW BODY OF THERMOPLASTIC MATERIAL

摘要

A process and apparatus for the production of hollow bodies from thermoplastic material by means of blow molding uses a blow molding mold which comprises at least first and second mold portions to enclose a generally tubular extruded preform which is expanded within the mold under the effect of an increased internal pressure within the preform. To provide for asymmetric closing and/or opening movements of the mold portions relative to the preform, the blow molding mold is displaced as an entirety parallel to the direction of the opening and/or closing movements of the mold portions, more especially during the mold closing and/or opening procedure, so that an additional motion is superimposed on the movements of the mold portions.