METHOD FOR PRESSING PRECISION GLASS OBJECTS, METHOD FOR MANUFACTURING A MAL MAL AND PRESSING FOR PRECISION GLASS ITEMS.

摘要

A method for the manufacture of a mould intended for the precision moulding of glass articles, notably aspherical lenses. The desired shape and dimensional accuracy are imparted to a mechanically treated preform by an accurate polishing operation. Subsequently, the polished preform is prestressed and reinforced by a chemothermal treatment. The surface of the mould thus obtained comprises an edge zone which is subject to compressive stress and which changes over, via a neutral stress-free zone, to the core which is subject to tensile stress. The mould in accordance with the invention has a longer life and produces moulded products having a quality which is higher than that of products made by means of known moulds.