Karl Mayer: “Multiaxial CFRP pultrusion profiles grow in mobility sector”

At upcoming JEC World 2026, Karl Mayer Technical Textiles will introduce new application potentials for multiaxial non-crimp fabrics in combination with the pultrusion process.

The advancement of the tried-and-tested pultrusion process enables the cost-efficient production of complex CFRP multi-chamber profiles, which are used in the Cetrovo high-speed metro. The world’s first carbon-intensive lightweight rail vehicle of this type is designed for speeds of up to 140 km/h. The rapid speed of travel results in complex material stresses that require multiaxial reinforcement.

The textile-reinforced CFRP pultrusion profiles with a wall thickness of up to 25 mm are designed for multidimensional load cases. This makes them ideal for use in the highly stressed side walls of the lightweight railcar body in the Cetrovo. There, they transfer longitudinal forces of up to 1,200 kN, absorb high bending loads and contribute significantly to weight reduction – a total saving of 30% was achieved.

“Weight reduction is particularly important for underground and suburban railways. Due to frequent stop-and-go operation, mass inertia plays a key role in energy consumption compared to air resistance,” explains Prof. Dr.-Ing. Andreas Ulbricht, Managing Director of CG Rail GmbH.

Advanced process, additional reinforcement through multiaxial non-crimp fabric

CG Rail developed the CFRP profiles together with partners in Dresden on behalf of the Chinese rail vehicle manufacturer CRRC, specifically adapting the pultrusion process for this purpose. The modifications enable the production of innovative multi-chamber profiles with multiaxial continuous fibre reinforcement and lengths of over 20 m.

As additional reinforcement to conventional unidirectional longitudinal reinforcement, the CG Rail team primarily uses non-crimp fabrics from a Cop Max 5. The multiaxial warp knitting machine from Karl Mayer impresses with its high productivity, flexibility and consistently high material quality. The reinforcement fibres can be inserted at angles of +/- 20° and with a pitch of 1°.

“The reinforcing fibres are precisely integrated into multiaxial non-crimp fabrics without any undulations. We can fully exploit their mechanical performance potential. In addition, they are better fixed in the textile surface than in comparable woven fabrics,” explains Prof. Dr.-Ing. Andreas Ulbricht.

From the laboratory to the rails

The first CFRP lightweight train celebrated its premiere at InnoTrans 2018 in Berlin. An advanced prototype was a highlight of the World Transport Convention in 2024. Since January 2025, the Cetrovo 1.0 has been in service on Line 1 in the Chinese port city of Qingdao (Shandong Province).

CG Rail is already working on further projects. CFRP pultrusion profiles open up new perspectives, particularly in the commercial vehicle sector – for example, for ultra-light frame structures such as lattice frames for buses or semi-trailers for trucks. Experience shows that the lightweight potential compared to metal profiles is between 20 and 50%.

“Our composite machines also produce bi- and multiaxial non-crimp fabrics of glass, which are then further processed using the pultrusion method. The variety of materials and their laying angles offer exciting prospects for lightweight construction applications, which we would like to discuss with visitors at JEC World,” says Kay Burkhardt, Product Manager at Karl Mayer Technical Textiles.

Karl Mayer Technical Textiles will exhibit at JEC World in Hall 5, booth C46.

Cover photo: Pultrusion profile — longitudinal beam of underfloor cladding, cross-section (source: Karl Mayer)