New Borealis biaxially oriented polypropylene reduces weight and improves transparency of plastic bottles

The new Borealis RF926MO polypropylene (PP) injection stretch blow moulding (ISBM) grade provides enhanced performance owing to its biaxial orientation. The new grade can reduce weight by more than 30% compared with extrusion blow-moulded high-density polyethylene (HDPE) grades. The new PP grade provides excellent transparency and gloss levels, can save up to 30 to 50% on energy costs in production, and RF926MO’s processing window is significantly broader than other PP materials.

The first commercialisation of this new grade has begun with the converter GSG Italy in collaboration with SMIFORM Italy as equipment manufacturer and Hofstetter Switzerland as bottle preform designer.

The initial project for GSG was triggered by rapidly growing demand from GSG’s customers for moulded plastic bottles. GSG would have required two HDPE extrusion blow moulding machines to meet the rising demand, however, production space constraints at GSG’s plant prevented this investment. The needed output is being supplied by one SBM machine from SMIFORM that uses the Borealis PP grade formulated for the ISBM process. The desire for product differentiation through higher performance and improved aesthetics were additional drivers for GSG to seek out a new PP-based material.

Follow-on projects are in progress for the new grade in a variety of stages, from technical approval to evaluation and pilot production.

“The new PP-based material and converting technology broadens the market for PP bottles,” said Gianbattista Gozio, GSG. “We benefited greatly from Borealis’ willingness to drive innovation with new materials and processes.”

“We see a new, burgeoning market for polypropylene injection stretch blow moulding,” said Max Wachholder, Application Marketing Manager, Borealis. “Cooperative work with machine makers, preform producers and other important partners in the value chain is moving forward rapidly as well.”