Blow moulding mandrel with annular air outlet(s) - to cause progressive detachment of the parison

摘要

Mandrel for blow moulding tool has a rigid neck used to calibrate the bore of the parison and a core tube which can extend to open an annular outlet between bevelled mating faces between the end of the neck and the shoulder to the tube. The outlet axis is divergent from the mandrel axis. The conical air jet issuing from the inclined annular die promotes early and uniform sepn. of the inner surface of the parison from the surface of the mandrel, producing parisons of radially uniform wall thickness. The short contact land length ensures a low and reproducible degree of mandrel/parison parison friction regardless of the length of the mandrel generated.