A reciprocating blow molding unit includes an extruder screw foundation and an extrusion unit coupled to the extruder screw foundation. The extruder screw foundation includes a screw housing formed to include an interior cavity configured to receive polymeric material. The extrusion unit includes an extruder screw arranged to lie at least partially within the interior cavity and is configured to rotate about a longitudinal rotation axis to advance the polymeric material through the interior cavity.

Amendments to the abstract were made herewith to correct minor informalities with the parent application. A clean copy of the abstract is included herewith on a clean sheet. Even in light of the amendments no new matter is being added and all amendments are fully supported by the specification as filed.

A die group with a forming head for forming a tubular parison made of plastic material with a female die, which defines an internal through-cavity with a vertical die axis, a female die holder element, rigidly connected to the female die, and a housing body which defines a vertical reference axis for coupling with a distribution duct of the forming head and supports the female die holder element allowing relative movement thereof in a longitudinal/transverse plane. A first electric driving actuator is supported on the housing body and rotationally drives a first output element coupled with the female die holder element by means of a first transmission mechanism so as to move the female die holder element in the longitudinal/transverse plane with respect to the housing body, in accordance with a first isometric transformation.

A reciprocating blow molding unit includes an extruder screw foundation and an extrusion unit coupled to the extruder screw foundation. The extruder screw foundation includes a screw housing formed to include an interior cavity configured to receive polymeric material. The extrusion unit includes an extruder screw arranged to lie at least partially within the interior cavity and is configured to rotate about a longitudinal rotation axis to advance the polymeric material through the interior cavity.