Continuous Rotary Wheel Extrusion Blow

  • Continuous extrusion process
  • Bottles: laundry, motor oil, personal care, beverages
  • Typical Resins: HDPE, LDPE, extrudable PET(ePET), Nylon
  • Machinery: Graham Engineering, Techne, Kautex, R&B Plastics
  • Often multiple extruders for multiple layers, including oxygen barrier layers
  • Typical layers would be virgin, re-grind, adhesive, barrier, virgin + color, etc.
  • Dies are not typically polished
  • When purging, it is desirable to keep the machine running, because wheels take long periods to start up; and those that extrude up, can be quite messy during purging.
  • Best to use a grade with good melt strength and low MFI in order to hold a parison (assuming that taking the wheel down is not desirable).
  • Profile the die while running – this will mimic the “Disco Purge” effect
  • If keeping the wheel running, do not blow the parison – inorganics in the purging compound could scuff polished mold cavity surfaces.
  • Seal the extruder and head with a sealing grade commercial purging compound during extended downtime events.