Finding the Shape of a Flexible Blade for Free-form Layered Manufacturing of Plastic Foam Objects

The need for rapid, cost-effective and finish-less manufacturing of large sized, sculptured, physical models from various soft materials is increasing in several fields. For objects fabricated from plastic foams an advantageous approach is freeform, thick-layered manufacturing. Although it is technologically demanding, to achieve the best results (a) computer definition of the geometry has to be accurate, (b) the geometric model has to be directly sliced, (c) higher order approximation of the nominal shape is necessary, and (d) a quasi-free-form working out of the front surfaces of the layers is needed. The authors have developed the mathematical/technological fundamentals and process of free-form cutting based on heated flexible blades. The shape and the relative positions of the flexible blade are controlled continually as needed by the normal curvatures of the front faces of the layers. The paper presents the computation methods for physically-based and geometrically-based modeling of flexible blades. The algorithms for approximating curve generation and curve matching are also presented. The paper extends to some of the most important aspects of the global thick-layered fabrication process.