METHOD FOR PRODUCING A LITHIUM SILICATE GLASS PREFORM AND A LITHIUM SILICATE GLASS CERAMIC PREFORM

摘要

The invention relates to a method for producing a blank of lithium silicate glass a starting composition of at least 8 wt-% of a stabilizer selected from the group consisting of ZrO2, HfO2, and mixtures thereof, wherein the method includes the steps of mixing the raw materials comprising the stabilizer in powder form, wherein the powder of the stabilizer has a particle size d50=x with 0.3 μm≦x≦1.5 μm, melting the raw materials in a crucible at a temperature TAU and storing the melt in the crucible for a time tH, pouring the homogenized melt into molds, wherein the melt flows out of the crucible with a discharge temperature TAB being TAU≧TAB, wherein the filling of the molds and the molding of the melt in the molds takes place with a cooling rate A.