Round mouldings cast from liq. esp. molten glass - which is continuously or centrifugally cast onto layer of molten tin, esp. to make tubes, lens blanks, or curved mirrors

摘要

A specific amt. of a heavy inert liq., pref. a metal and esp. molten tin, is fed into a rotating chamber; and then a molten material, esp. glass, is cast onto the tin and is continuously or discontinuously removed from the chamber. In one pref. mfg. plant, molten tin is located in a horizontal, tubular rotor, which is used for the continuous casting of glass tube. Another pref. mfg. plant consists of a vertical centrifugal casting plant, in which molten tin is rotated so it forms a concave surface on which a parabolic glass casting can be solidified. The atmos. above the molten tin pref. consists of an inert gas. Useful for casting glass tubes; large parabolic blanks for mirrors; or lens blanks. Casting or centrifugal casting of molten glass on a layer of molten tin produces prods. with excellent surfaces and free from defects such as gas bubbles.