LaWiKo

Motivation

Many economic hubs in Germany are undergoing a complete structural transformation from coal mining and valorization to future-oriented sites for renewable energies and environmentally friendly technologies. In this context, in addition to focusing on renewable energy sources, energy storage plays a decisive role in achieving EU sustainability goals such as climate protection, affordable and clean energy, and resource utilization.

The application-oriented R&D project LaWiKo focuses on developing customized prerequisites for the production of lightweight containers made of fiber-reinforced plastics for the mobile storage of hydrogen and hydrogen-based energy carriers. The targeted development of a high-rate manufacturing technology utilizes thermoplastic pre-consolidated tape materials, which are processed in a continuous wide strip winding process into rotationally symmetric container structures. A precisely controlled laser-based local heating enables autoclave-free consolidation of the materials.

In combination with the technology modules of joining and coating, unique manufacturing possibilities are created to produce test specimens and prototypes efficiently with property profiles previously unattainable. In doing so, the excellent scientific competencies in plastics processing of the Institute for Lightweight Structures and Polymer Technology at TU Chemnitz, particularly the wide strip winding technology for producing closed thermoplastic composite components, are synergistically combined with the laser and process engineering expertise in laser in-situ joining of Fraunhofer IWS in Dresden.

Objectives and Approach

In previous projects, large-scale composite parts and joints made of thermoplastic multidirectional laminates were successfully produced using the CONTIjoin technology developed by Fraunhofer IWS. Conventional lay-up systems increasingly rely on the use of solid-state and diode lasers, whose wavelengths are primarily absorbedby the reinforcing fibers.In contrast, the high absorption of the CO₂ laser radiation used in CONTIjoin within the polymer matrix represents a decisive advantage in terms of thermal process control. The focus of the project is the production of cylindrical tank structures made of multidirectional fiber-reinforced organo sheets with a high degree of lightweight construction, which are intended for use as high-pressure hydrogen storage tanks.

On behalf of Fraunhofer IWS, two key research focus areas are addressed:

• Development/adaptation of a laser system for wide strip winding technology
• Laser structuring and thermal spraying of a barrier layer on pressure vessels

Innovation and Perspectives

The collaboration of both project partners enables the exploitation of the following potentials:

• Material innovation: The combination of laser processing and innovative polymers contributes to the development of new materials with tailored properties.
• Interdisciplinary research: Collaboration among experts from different fields enables interdisciplinary research approaches and the examination of complex questions from diverse perspectives.
• Industrial application: The integration of expertise in laser technology and plastics processing also offers potential for developing industrial solutions with high standards in terms of both production efficiency and product quality.