| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a manufacturing method of a magnetic disk glass blank, capable of suppressing the occurrence of a shear mark of a molten glass, or causing the shear mark to be generated on a shallow position when the magnetic disk glass blank is manufactured using press moulding, and further improving the production efficiency of the glass blank in comparison with the prior art.SOLUTION: The manufacturing method of a magnetic disk glass blank includes the steps of: cutting a flowing molten glass to produce an agglomeration of the molten glass; dropping the agglomeration; pressing both sides of dropping route of the agglomeration with a pair of presses; adjusting, before the cutting the molten glass, viscosity of the surface of the flowing molten glass for restricting the occurrence of the shear mark on the glass blank to be manufactured. The molten glass with the adjusted surface viscosity is cut to thereby produce the agglomeration.</p> |
