Page 19 - ILK Research Report 2020

Doctorate Dr.-Ing. Tilman Orth

LED-based heating system for Automated-Fibre-Placement

Supervising Professor: Prof. Dr.-Ing. Niels Modler

Automation is a key enabler for the widespread structural further profit from the new heating system a numerical
application of carbon fibre reinforced plastics in civil air- model of the heat transfer has been developed to accu-
craft construction. Nonetheless, several components of rately calculate the heat up in the material. By taking into
the applied automated-fibre-placement (AFP) machinery account the impact of each LED individually, the model
in thermoset layup still offer room for optimisation. This also predicts the spatial distribution of the occurring heat
is especially true for the typical infrared lamp based heat- transfer and thus allows an active control of the tempera-
ing system which is significantly less understood and well ture field during the process. Thereby, a parameter set
developed than in layup of thermoplastic material where that provides a very homogenous temperature field with-
diode lasers are utilised. Those lasers offer a short reaction out any additional components has been determined and
time, precise control and a homogenous heat up, while the validated experimentally.
infrared lamps are less bulky, considerably cheaper and
do not require sophisticated safety precautions. Through the combination of the advantages of infrared
and laser systems, the innovative LED-based heating sys-
Therefore, a new heating system based on the use of a tem offers significant improvements for the optimisation
multitude of LEDs as radiation source has been devel- of the industrial AFP. Cost reduction can be achieved by
oped with the aim to combine the advantages of both utilising off the shelf components as well as their flexible
pre-existing systems. An analysis of the process and the arrangement and integration into newly developed layup
material allows choosing the most suitable LEDs which systems. Improved energy efficiency and lower mainte-
have been arranged into a heating device that is capable nance costs further reduce the cost of ownership. The
to actively control the profile of the emitted radiation to quality of the layup process profits from a more reliable
enable an adaption to different processing situations. A surface temperature measurement, allowing for more
test campaign in a dedicated laboratory environment has robust control loops which are also benefiting from the
proven the reliable heating according process specifica- LEDs short reaction times ultimately allowing faster overall
tions as well as demonstrating short reaction times. To cycle times especially for complex parts.

Laboratory placement unit with LED-based heating system (left), irradiation and heat transfer model (right)

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