BAVARIAN RESEARCH ASSOCIATION FLEXIBLE TOOLS
B2: Development and production of form flexible tools for injection molding
The present market trends to customize products also cause the mold and die section to investigate new technology, because fewer products have to pay for the tools which they are made with. Economic solutions for injection molding or die casting are limited by the smaller number of products being produced with a single tool. Modularization and standardization of segmented molds only offer a limited reusability of the tool. Based on this understanding, form-flexible tools for injection molding are developed at the iwb to allow different geometries being generated with a single tool. One of the promising solutions for such a form-flexible tool is based on the principle of a “pin-cushion”. This cushion is made of a large number of square pins which are arranged in such a way as to allow relative movement to each other. Based on a 3D-CAD model, the STL-file is used to generate the actuation of the individual pins by an especially developed software. These pins are actuated by means of a positioning device and fixed against unintended movements with a pneumatic fastener. The resolution and/or accuracy of this form-flexible tool is limited by the geometry of needles being used. At present, needles with a 0.4 mm square cross-section are used with the intention to reduce the width when further experiences and results become available. With the tool under development, future products can have dimensions of up to 100 x 100 x 50 mm³. For products showing undercuts special machined inserts will be clamped between the needles. These inserts can be manufactured quite simply and easily be replaced manually after each molding step.