ThermHex Waben and Fraunhofer IMWS Advance Honeycomb Production with Innovative Organosandwich Technology

Over the past decade, ThermHex has consistently reported breakthroughs in the ThermHex thermoplastic honeycomb technology, a patent held by Belgium’s EconCore. ThermHex Waben GmbH, EconCore’s German subsidiary that manufactures PP honeycomb cores for economical sandwich panels, has partnered long‑term with the Fraunhofer Institute for Microstructure of Materials and Systems (IMWS) in Halle. Together, they have carried out multiple R&D projects focused on streamlining production and processing techniques for high‑volume honeycomb cores and the Organosandwich.

The Organosandwich is a semi‑finished product comprising two ultra‑thin thermoplastic fiber‑composite face sheets (organosheets) separated by a thermoplastic honeycomb core. It delivers exceptional stiffness at minimal weight, eliminating the need for additional stiffening ribs.

When the Organosandwich is integrated inline with the honeycomb core in a continuous process and bonded directly, the resulting components become highly cost‑efficient. Fraunhofer IMWS has developed the TS‑molding technology—under the brand name TS‑molding—to thermo‑form and functionalize these components via injection molding in very short cycle times.

The TS‑molding technology, a direct outcome of this collaboration, is poised to enhance ThermHex’s fully automated production line. It will help the company reach its ambitious goal of 2.2 million pounds of Organosandwich and honeycomb cores this year, with projected annual growth of 10 % to 20 % thereafter.

Traditionally, honeycomb cores are produced by cutting each layer from a block and then laminating them—an approach that is both complex and costly. ThermHex’s continuous in‑line process eliminates these steps: after extrusion, the web is rotationally vacuum‑formed, folded, laminated, and cut to the desired length—all on a single production line. This integration significantly reduces resource consumption and manufacturing costs.

At the Halle facility, ThermHex can produce honeycomb cores ranging from 0.2 in (3 mm) to 1.8 in (30 mm) in thickness, featuring very small cell sizes for superior surface quality. Individual lengths can reach up to 19.69 ft (6 m). These cores are widely used in the fiber‑composite sector to manufacture sandwich panels and components for truck bodies, automotive interiors, prefabricated bathrooms, and swimming pools.

Sandwich construction offers tremendous weight‑saving potential. By separating two thin face layers with a lightweight core, weight reductions of over 80 % are achievable compared to monolithic structures—alongside substantial material cost savings.

According to the collaborators, ThermHex’s single‑line production process is the only viable means to achieve cost‑efficient, continuous manufacturing of Organosandwich semi‑finished products.

“This collaboration between ThermHex and Fraunhofer IMWS will bring industry‑leading changes to honeycomb technology,” says Mona Boche‑Würfel, Marketing and Communications Manager at ThermHex. “The technology we develop will enable the mass production of nearly CO₂‑neutral sandwich panels with very short cycle times as part of a highly cost‑efficient process.”

ThermHex PP honeycomb cores with thermoplastic top layers are already employed in the automotive sector, including the trunk floor of the Maserati Ghibli and Jaguar F‑Type, and the trunk cover of the Toyota Prius PHV.

The Organosandwich joint research project was funded under the EFRE program by the European Union through Investitionsbank Saxony‑Anhalt.