Propylene-based Elastomer Enables Foam Building Blocks from Mixed Recyclates

Incorporating recycled content into foamed products, particularly in the building and construction sector, can compromise product consistency, mechanical strength, and overall performance. Without effective solutions to process and reuse these mixed plastic streams, designing for recyclability remains a formidable challenge. 

To address the challenge, a collaborative effort across the value chain was initiated, involving key industry players including Erema, Moxietec, Engel, and ExxonMobil with Vistamaxx™performance polymers playing an important role. Erema, a global leader in plastics recycling systems, produced high quality pellets using its unique filtration and degassing system. The process handled a mixed stream of recyclates comprising 95% PP rigids and 5% PE film supplied by Prezero. 

Moxietec , known for its innovative foam technology, utilized its technology to produce lightweight locking blocks that can be used in the construction sector without reducing impact strength which other conventional foaming processes often compromise. The addition of Vistamaxx performance polymers in dosages of 5% helped to improve the impact resistance and toughness of the foamed components, enabling the incorporation of recycled content without compromising structural integrity. 

Engel, a leading manufacturer of injection molding machines, combined all the attributes of the value chain into the production of thick-walled foamed blocks. These blocks, designed for the building and construction industry, offer design flexibility for single walls, double walls, and corner structures.

Dart drop impact testing shows that foam parts manufactured using Moxietec technology exhibited a 10% improvement in impact strength—measured by total energy at break—compared to conventional solid parts. This enhancement was particularly significant given that traditional foaming processes typically compromise impact performance relative to solid materials. 

In addition to mechanical benefits, Moxietec technology enabled incorporation of recycled polypropylene content (rPP) with a final part weight approximately 30% lower than conventional solid parts. Further performance optimization was achieved through the incorporation of Vistamaxx performance polymers without sacrificing the weight reduction.