A kind of clarification method of alkali-free glass melting under reduced pressure

Abstract

The invention relates to an alkali-free glass decompression founding and clarification method which comprises processes of batching of existing alkali-free glass batches, warming founding, clarification, iron plate casting forming, annealing, cutting and polishing and is characterized in that before warming founding, firstly, a melting furnace is subjected to decompression processing, a vacuum degree in the furnace is controlled within a range of 500Pa to 100,000Pa, and consumed time is 0.5 to 1 hour; and after clarification is ended, air is introduced into the melting furnace, and internal and external air pressures of the furnace are regulated to be balanced. The alkali-free glass decompression founding and clarification method disclosed by the invention has the advantage that the batches are subjected to decompression founding and decompression clarification so as to implement uniformity and completeness of the reaction among the batches, reach the optimal founding, clarifying and homogenizing effects and obtain high-quality alkali-free glass which is small in number of residual bubbles, small in diameter of the bubbles and excellent in homogeneousness.

Description

technical field

[0001] The invention belongs to the field of alkali-free glass preparation, and relates to a method for purifying alkali-free glass by melting under reduced pressure. Background technique

[0002] The glass substrates used for displays such as liquid crystal display devices are required to be substantially free of alkali metals. Since the glass raw materials of alkali-free glass do not contain alkali metal compounds substantially, and the content of alumina is high, the process of glass melting and clarification is slower than that of conventional sodium Lime-silicate glass is much more difficult, and glass samples obtained by ordinary atmospheric pressure melting and clarification have more air bubbles.

[0003] Bubbles are the most common defects in the glass melting process, which will affect the appearance, transmittance, mechanical strength and hardness of glass products. When it is used, it cannot meet the requirements of glass substrates for displays ...

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