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Low Tg Glass for Precision Molding

LOW TRANSFORMATION TEMPERATURES SUITABLE FOR PRECISION MOLDING

Precision molding is one of the state-of-the-art- technologies for the volume production of complex lenses, e. g. aspheres, for various applications
SCHOTT offers various optical glasses specifically developed for precision molding – the so-called low Tg glasses, such as P-SF68, P-SK57Q1, P-SK58A and P-BK7.
Low Tg glasses have a glass transformation temperature suitable for precision molding and a special glass composition to decrease the tendency for devitrification and to reduce the reaction with mold materials within the molding temperature range.
During a precision molding process, a polished or fire polished preform is shaped into a final geometry, while conserving its surface quality. The typical temperature range for the molding process is between 500 °C and 700 °C, enabling the extension of the operating lifetime of the mold material and a significant time reduction of the press process.
SCHOTT low Tg glasses are provided in the form of optical glass rods as well as ball lenses in different formats.