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.