Novel Processes for the Machining of Tool Inserts for Precision Glass Molding

In this chapter, two new process chains are introduced using novel processes for the machining of complex molds by diamond grinding and diamond profile grinding in combination with a machine-based abrasive profile polishing. Finest grained diamond grinding wheels with a metal bond provide superior grinding results. But the combination of a metal bond and very fine grains causes great difficulties for the trueing and dressing operation using conventional methods. For the machining of rotational symmetric mold inserts the novel process of electrochemical in-process dressing can be applied to achieve optical surface qualities without a subsequent polishing process.

For more complex shapes a grinding wheel with a micro-profile is needed. The pre-dressing and profiling of the difficult to machine grinding wheels is done by the unconventional Wire-EDM process. To achieve a surface roughness of the profiled mold in optical quality a subsequent polishing process is necessary. Therefore the novel process of diamond profile grinding in combination with a subsequent machine-based profile polishing is introduced.