CircularInFoam: High-performance halogen-free insulation materials for industrial applications

PLA pellets and foam samples for the next generation of sustainable insulation materials with improved fire resistance. © Fraunhofer CCPE

Through the CircularInFoam project, the Fraunhofer Cluster of Excellence Circular Plastics Economy CCPE is developing sustainable, high-performance insulation materials based on polylactide. Halogen-free flame retardant systems, modular masterbatch solutions, and industrial scalability are opening up new possibilities for safe, low-emission, and economically competitive insulation materials.

The demands placed on modern insulation materials are constantly increasing: In addition to high energy efficiency, fire safety, regulatory requirements, and sustainability are increasingly becoming the focus of the construction and plastics industries. At the same time, there is a growing need for materials that can be integrated into existing industrial processes and support circular value chains. With the “CircularInFoam” project, Fraunhofer CCPE is addressing precisely these challenges and developing new insulation solutions with halogen-free flame retardants and a sustainable material base.

Sustainable materials with industrial relevance

The research focuses on insulation systems based on polylactide (PLA). The goal is to gradually replace petroleum-based raw materials while meeting the technical requirements of modern facade and building insulation.

The participating Fraunhofer Institutes combine their respective expertise across the entire value chain: Fraunhofer LBF develops halogen-free, modular flame retardants, thereby laying the foundation for sustainable and safe material systems. Building on this, Fraunhofer ICT investigates the industrial processability of the developed formulations, particularly the foamability of the materials and their influence on the mechanical properties of the foams. Finally, Fraunhofer IBP evaluates the thermal properties and assesses their suitability for future insulation applications with regard to the release of hazardous substances in contact with water.

The resulting material concepts combine sustainable raw materials with halogen-free flame retardants and are specifically designed for industrial processability. Modular masterbatch strategies enable flexible adaptation to different applications and production processes.

“With CircularInFoam, we demonstrate that sustainable raw material systems and effective fire protection are not mutually exclusive, but can be specifically combined. In particular, the development of halogen-free, modular flame retardant systems opens up new avenues for the industry to technically improve existing insulation products while simultaneously fulfilling regulatory and environmental requirements. Scalability is crucial here—and this is exactly where our masterbatch and process concepts come into play,” says Robert Lang, project manager at the Fraunhofer Institute for Chemical Technology ICT.

Improved Fire Safety Through Modular Flame Retardant Systems

Initial results indicate significant potential for optimizing fire safety performance. In the case of expanded PLA (EPLA) systems, initial tests suggest inherently favorable fire safety properties. Further investigations are intended to further improve classification and performance.

In addition, halogen-free flame-retardant formulations for polystyrene systems were developed as part of the project and successfully tested in initial trials. The work is still in the development phase and is open to collaborative projects.

Competitive insulation performance and lower emissions

In addition to fire protection, CircularInFoam also addresses thermal performance. The thermal conductivities achieved to date are within the range of established EPS standards, thereby laying the foundation for marketable, sustainable insulation materials.

At the same time, halogen-free flame retardant systems support the development of sustainable, regulation-compliant foams with lower environmental and health impacts while maintaining high fire safety. This creates new opportunities for industrial companies to develop sustainable product portfolios and strengthen green product claims.

Collaborations and Technology Transfer

CircularInFoam offers industry partners concrete approaches for joint development. In particular, the oxyimide-based flame retardant technologies and the associated masterbatch solutions open up potential for industrial applications and rapid market launches.

In the next project phases, Fraunhofer CCPE plans further demonstrators, in-depth fire tests, and pilot runs in collaboration with industry partners. Companies, material manufacturers, and users are invited to actively participate in the further development of these technologies and to jointly advance sustainable solutions for the next generation of insulation materials. Fraunhofer CCPE is available to interested partners at any time for collaborations, development projects, and technology transfer.

Fact box

CircularInFoam at a Glance

Project Objective: Development of sustainable, high-performance insulation materials with halogen-free flame retardants for facade and building insulation.

Materials: PLA (polylactide), EPS/EPLA systems