Tool System for UV induced micro moulding of biomedical disposables

A new approach for the generation of double-sided microstructured polymer films is presented based on injection-molding of urethane- and epoxy-based acrylates that are polymerized by irradiation with ultraviolet light (395 nm). Compared to hot embossing, this offers not only working under ambient conditions, but also a reduction of cycle time as well as flexibility regarding adjustment of the mechanical and/or chemical properties of the resulting polyacrylate film. A setup, consisting of the mold with the microstructured insert and two LED lamps emitting UV-light moved by a controllable stepper motor and a computer-based controller, was installed and successfully used for the fabrication of double-sided microstructured polyacrylate films.Therefore a new and innovative tool system for 2-component UV induced micro moulding of biomedical disposables was developed. The geometrical dimensions of the microstructures (e.g. fins, channels, sharp edges and slopes) require different technologies to machine the tool inserts. Therefore micromilling and m-laserablation technologies were used in combination attached by laser polishing operations in special areas. A highly precise, complex designed tool system with mechanically moveable areas is needed to fill the tool with the 2 various chemical compositions. The paper presents the tool concept and explains the investigated surface treatment options.