Overview
Carbon-fibre-reinforced-polymers (CFRP) have known advantages and are typically used for applications in aerospace engineering. Up to date existing mechanical combined with chemical process produce only low-quality recovery of carbon-fibres from the polymer matrices at high costs. Electrodynamic fragmentation has the potential to overcome this situation. The method is based on the interaction of an electrical discharge with a solid between 2 electrodes immersed in water. Selective liberation is caused by a detachment along the interfaces in a tensile stress regime, which allows an intact recovery of the components. Objective of the herein presented proposal was the implementation of a specific electrodynamic fragmentation plant to process CFRP’s with the goal to regain non-damaged carbon fibres, which then can be reused. SELFRAG is a manufacturer and the expert of electrodynamic fragmentation equipment and elaborated above target during several work package. The investigation started with the behaviour of different CFRP’s in the SELFRAG process in regards of different process conditions, equipment setups and process strategies. Liberation of the fibres were assessed by external laboratory. In the following work packages these results were optimised, transferred during up-scaling and prototyping with the final goal of demonstration plant. The stage/gate organisation with achieved milestones guarantees a realistic project management. SELFRAG has the expertise to perform this process development and process engineering, which matches the topic of the call completely.
Future application of this innovative technology means a boost of competitiveness and growth in European Union along with creating jobs. Accelrration of development of clean air technologies for air transport in the EU was achieved.
Funding
Results
Executive Summary:
The usage of Carbon Fibre Reinforced Polymer (CFRP) composites in aerospace engineering has increased considerable in last decades because of their efficient and lightweight structure for better airplane performance. This represents a challenge to the aviation industry. As no real recycling strategy in economic rages is available, no efficient end-of-life solutions for airplanes exist. Current mechanical combined with chemical processes target to remove the resin matrix from the carbon fibres by thermal degradation. Problematic is the low-quality product recovery of carbon powder with little to no economic value. Other solutions like incineration and landfilling results in the complete loss of the material. The current downcycling of CFRP material is critical. New methods are being developed in order to increase the quality of the recovered carbon fibres by oxidation and micro-wave pyrolysis. All used and investigated processes so far are limited either in liberation, recovery of good quality carbon fibres, throughput, high operating costs and/or insufficient industrial scale.
Within the Clean Sky project JTI-CS-2012-1-ECO-01-053 - Disintegration of fiber-reinforced composites by electrodynamic fragmentation technique - SELFRAG investigated the potential of electrodynamic fragmentation to improve the recyclability of CFRP waste from end-of-life aircraft components. SELFRAG proposed a detailed test plan; the work is broken down into 3 main work packages. Each work package was subdivided into several tasks, which provides milestones and deliverables. The principle of electrodynamic fragmentation provides a selective physical process using high voltage pulse power discharges to liberate composite materials along material interfaces.
The main objectives of the project were the process development to treat CFRP composites for best fibre recovery and to install a demonstrating plant in TRL 6. This included investigations to the recyclability of resulting products and the potential recycling rate. Lab scale tests indicated a recycling quote of 60% by the removal of polymer and losses. Tests to thermoplast PEEK material showed the recycling potential of the process by the complete reuse of the processed material in new parts with comparable material strength. In the process development best electrodynamic plant setup and process conditions were developed in regards of energy consumption, scale and fibre recovery in lab scale tests first. To construct and setup the demonstrator, the data was converted to upscale specification of the potential demonstrator. For the construction of the demonstrating plant the data was integrated in the equipment and flow-sheet design including electrodynamic fragmentation and material recovery devices. To treat CFRP material two general setup of the demonstrating plant were considered. Plant E was setup to treat CFRP.