Patent ID: 7244388

Claim:
A process for producing hollow bodies of thermoplastic material by extrusion blow molding, wherein an extruded tubular preform of plasticised material is disposed between parts of a blow molding mold defining a mold cavity for enclosing the preform, the preform is laid flat prior to closure of the mold halves transversely with respect to the extrusion direction and in a separation plane of the blow molding mold, in such a way that the preform extends beyond the lateral edges of the mold cavity of the blow molding mold, an increased internal pressure is produced within the preform to expand same within the blow molding mold, the parts of the preform extending beyond the edges of the mold cavity constituting bulge portions thereat, and prior to removal of the article from the blow molding mold the bulge portion produced after closure of the blow molding mold is cut open along its length at each side of the blow molding mold at the respective edges extending in the extrusion direction.