Extrusion Blow Molding
Processing • PHA
Extrusion Blow Molding
Extrusion blow molding forms hollow parts by extruding a parison, closing it in a mold, and inflating it to shape. For PHA, parison stability and melt strength are key to consistent wall thickness.
Best forBottles, containers, hollow parts
Key controlsMelt strength, parison programming, cooling
OutcomeLightweight parts with efficient cycle times
What is extrusion blow molding?
In EBM, the polymer melt is extruded into a tube (parison), captured by the mold, and inflated with air until it matches the cavity. After cooling, the part is ejected and trimmed if needed.
Where is it used?
- Bottles and containers
- Industrial canisters and ducts
- Lightweight hollow technical parts
What is PHA?
PHA (Polyhydroxyalkanoates) is a bio-based polymer produced through fermentation. It’s positioned as an alternative to conventional plastics and is valued for end-of-life options such as biodegradation and compostability, depending on grade and conditions.
How does PHA behave in blow molding?
- Parison stability: tune temperature and output for consistent wall thickness.
- Cooling profile: affects stiffness, shrink, and dimensional stability.
- Moisture control: correct storage/drying reduces defects.
- Shear management: avoid excessive shear to maintain melt behavior.
Practical considerations
- Use stable temperature zones and avoid overheating.
- Optimize die gap / parison programming for gauge uniformity.
- Validate cooling time for top-load and drop performance.
- Consider formulation support to widen the processing window.