noyau

CONT: [...] le soufflage s'effectue en général au travers du noyau.
OBS: Voir Figure 31 dans TECHN.

CONT: The preform mold consists of four major components: preform cavity, injection nozzle, neckring insert, and core rod assembly.
CONT: The core rod assembly ... has four functions or features: It forms the interior of the preform. It supports the parison or the bottle during transfer. It is the valve where air enters to expand the parison. The valve is located either in the shoulder area or in the tip, the location being governed by the bottle or core rod length-to-diameter ratio. Wide mouth bottles (that is, core rods with low length-to-diameter ratios) will usually have a shoulder valve. The core rod has a ""blow by"" groove. This annular groove, located near the seating shank ... is needed to seal the parison and prevent excessive air loss during bottle blowing and to eliminate elastic retraction of the parison during the transfer between cavities.
CONT: Even though the parison is exposed to the air, melt strength is not as crucial because of the support provided by the parison core rod.