Methd of filling a mold with an organic material in a liquid state to mold an optical element and molding method including this filling method

摘要

The procedure consists of a staged flow, starting from zero with an initial flow (A) and leading to a nominal flow rate (Dn) of over 40 grams per minute (g/min) which is maintained for a period (B) during which the mold is filled, and a final reduced flow (C) coming back to zero. The initial flow stage (A) has two phases: a first phase (A1) in which the mold is filled to a depth of of at least 2 mm, and preferably up to 7 mm, in its deepest part at a flow rate of under 20 g/min, followed by a second phase (A2) in which the flow rate is increased to nominal (Dn). The first phase itself is divided into two sections: a first section (A11) building up from zero to a first flow rate (Dd) of some 3 - 8 g/min, and a second section (A12) in which the first flow rate is maintained for a period of 4 - 10 seconds. The mold cavity is filled through a needle valve and an orifice in its base, and the polymerization of the molded material is initiated immediately after the cavity is filled.