FEP film enables innovation in 3D printing

In stereolithography, a light beam of a certain wavelength builds a desired 3D object in a bath of photo-polymerizing liquid plastic (photopolymer). Wherever the bundled light beam hits the liquid plastic, the latter solidifies.

Mr. Malte Hartmann, B.Sc. and his colleagues are experimenting with different materials in the course of a research work of the Vienna University of Technology at the Institute of Materials Science and Technology. From photopolymers with adapted mechanical properties, through composites to fully ceramic objects. "One of the problems of the process is relatively high pull-off forces after layer generation," explains Malte Hartmann. "The surface of the" working top ", i.e. the bottom of the tub in which the photo hardening liquid is located, must therefore be anti-adhesive against a wide variety of materials. In addition, it must not release any chemical compounds or particles to the liquid nor be attacked by it, i.e. it must be as chemically inert as possible. High mechanical stability against abrasion is just as desirable as a smooth and flat surface and certain stiffness. There are some material requirements that are almost impossible to meet if the costs and the effort are to remain within the limits."

A major exception is films made from AGRU's fluorinated plastics FEP (Fluorinated ethylene propylene). They meet all these requirements in a cost-effective manner. The basic principle here is the anti-adhesive effect and the chemical inertness as a property of fluoropolymer. In addition, FEP is transparent in thin layers. In the course of the research, the AGRU FEP film is therefore used as a coating on a glass surface and thus enables the stereolithography process to be improved in terms of speed and quality.