Michael Emonts

Transient thermal analysis of laser-assisted thermoplastic tape placement at high process speeds by use of analytical solutions:

This article presents a transient thermal analysis of laser-assisted thermoplastic tape placement at high process speeds. The article revises modeling simplifications made in the literature and introduces novel ones. Analytical solutions to the thermal problem are proposed, for the heating and the cooling period. The process analysis of high speeds assumes a high-power laser in combination with a well-functioning temperature control. Due to this assumption, the final (surface) temperature is kept equal in all analyzed cases. The process analysis will show that the through-thickness temperature distribution changes significantly at higher speeds and becomes the determining factor for the bond interface temperature. General conclusions about process design and limits of tape placement are drawn. Finally, novel control methods are presented, which promote a dual control of surface temperature and temperature distribution. It will be shown how this is achieved by appropriate setting of the laser power and heating length.

Fiber-Reinforced Plastics Enable New Prospects for Minimal Invasive Devices and Interventions

Since 20years, minimal invasive interventions help to realize successful treatments with minimal trauma for the patients. The medical devices that are used for minimal invasive interventions need to have several outstanding properties to realize all their functions in combination with the required small dimensions. Therefore, a high specific mechanical stiffness and strength, defined chemical, electrical and magnetic properties, as well as biocompatibility and visibility for different imaging methods have to be realized by the used materials. The Gold Standard materials for such minimal invasive devices are metals and special alloys as well as biocompatible plastics. These isotropic materials are limited in the performance of the listed requirements. Fiber-reinforced plastics (FRP) offer the possibility to face these requirements by the combination of different fiber and matrix systems in combination with special additives, so customized anisotropic materials can be designed directly for the intended usage. Especially for patient-friendly interventions under MRI control fiber-reinforced plastics are unrivaled to other materials. For the manufacturing of such miniaturized medical devices made of FRP, the Fraunhofer IPT develops production processes like a continuous and automated micro-pultrusion and micro-pullwinding process to ensure reproducible and high quality products with customized properties.

Automated Manufacturing of Fiber-Reinforced Thermoplastic 3D-Lightweight Components

Lightweight components and their energy-efficient production will form one of the most important key factors for the European industry to fulfil the increasing global demands e.g. energy efficiency, waste avoidance and reduction of CO2-emissions. Nowadays, manufacturing equipment for thermosetting composite materials is present, but a competitive system for the manufacturing of continuous carbon fiber-reinforced thermoplastic components was not yet available. Within the research project 3D-ThermoLay, the Fraunhofer IPT has developed a production system for the automated laser-assisted tape placement addressing intersectoral branches, e.g. public and private transportation, mechanical, chemical and civil engineering as well as consumer goods.