Sulzer Chemtech and Borealis have completed the development of an innovative process for the cost-effective extrusion of expanded polypropylene (ePP) beads.

Polypropylene (PP) is a highly effective material, offering advanced mechanical properties and being well suited for reusing and recycling. To support the large-scale adoption of ePP, Sulzer Chemtech is now launching a new and innovative production line. Developed together with raw material supplier Borealis, the resulting solution supports the end market efforts towards more circular solutions and is expected to cut manufacturing costs by up to 60%.

As opposed to conventional autoclave production methods, Sulzer Chemtech’s innovative system relies on extrusion with direct gas impregnation, offering an easy to implement alternative with a quick return on investment. Foam molders, such as packaging manufacturers, can implement the compounding line to considerably reduce the costs associated with material supply, warehousing and intermediate transportation. As a result, companies can offer ePP parts at more competitive prices while supporting the adoption of easy to recycle polyolefin applications.

Additional benefits include having full control over the properties of the ePP, such as bulk density, closed cell content and bead size distribution, as well as maximum flexibility in fine-tuning the recipes. Also, the highly automatized process keeps maintenance requirements low and simplifies operations. Besides, the extruded beads can be subsequently easily processed with standard steam pressure in steam chest molding machines to obtain molded bead foam products with specific shapes. In addition, Sulzer Chemtech and Borealis are developing an alternative that can use carbon dioxide, supporting different customer needs and plant settings.

“Collaborating with an industry leader like Sulzer has been a pleasure,” comments Christopher McArdle, Borealis Vice President Polyolefins Strategy & New Business Development. “Life demands progress. This innovation will drive further the adoption of our PP foam solutions, supporting the transition to a circular economy of plastics. This is how we re-invent for more sustainable living.”

Torsten Wintergerste, Division President of Sulzer Chemtech, concludes: “We are extremely pleased with the advanced ePP production line that we have developed together with Borealis. The result of this collaboration truly attests to the extensive expertise of both companies. Using our latest solution, customers will be able to benefit from cutting-edge equipment with enhanced performance as well as high-quality PP for the production of best-in-class foams.”