Towpregrod – Efficient process for the continuous production of CFRP lightweight rods

The project partner Schütze GmbH & Co is currently producing lightweight aerospace rods in CFRP sandwich design using an extrusion process in which a cylindrically shaped core material is covered with resin-impregnated carbon fibres parallel to the longitudinal axis of the rod. The unidirectionally reinforced sandwich rods have very good weight-related mechanical properties and are used, for example, as lightweight, highly rigid and high-strength structural stiffening components such as support struts or steering rods. However, the current process only allows the production of fibre layers oriented unidirectionally in the longitudinal direction of the rod; angled layers must be produced separately in an offline process. The continuous introduction of angled layers in the production process and the use of pre-impregnated fibre rovings significantly expand the range of applications for sandwich rods and enable resource-saving, future-oriented production.

Objective of the project

We aim to develop and research a multi-orbital TowPreg layup system for the application of radial stiffening layers with variable fibre angles on axially reinforced TowPreg sandwich rods. The radially distributed layup units, which rotate around the core, enable full-surface continuous production of torsionally reinforced rods. The technology development is focussed on the subsequent use in small series production. Special attention is therefore paid in development and system research to ease of operation, short changeover times, flexible scalability and reliable, robust process control.

Advantages for companies

• The flexible production technology opens up new possibilities in the design of CFRP sandwich rods
• The continuous and tool-free process allows both small and large series to be realised economically

Procedure

Within the project, the project partner Schütze is conducting process development and research for the placement of pre-impregnated rovings, so-called towpregs, in the direction of the rod. We are developing and researching a multi-orbital layup unit to provide the rod with angular layers in the second process step. For this purpose, two orbital carriers rotating in opposite directions continuously place the towpregs on the rod. Thanks to the modular design of the system, a wide range of CFRP rods can be covered. Rods with a diameter of 15 - 80 mm and angular positions in the range of 30° - 85° can be produced in lengths of up to 30 m.

Do you have a possible application for CFRP sandwich rods or do you need support with design and production?

Contact Marco Bogenschütz by e-mail at bogenschuetz@ifw.uni.hannover.de or by telephone on +49 4141 7763825.