초록 ▼

The present invention relates to making optical articles such as opthalmic lenses by molding and, in particular, to using a continuous extrusion-compression molding method to make plastic lenses whereby a polymer melt is fed from an extruder or melting apparatus to a first die of a plurality of rota

The present invention relates to making optical articles such as opthalmic lenses by molding and, in particular, to using a continuous extrusion-compression molding method to make plastic lenses whereby a polymer melt is fed from an extruder or melting apparatus to a first die of a plurality of rotating or conveyed sequentially processed compression die sets comprising a first die and a second die. The die sets are positioned on die supports on a rotating turntable or conveying system, the lenses formed by compressing the die sets with pressing means associated with each die support, the lenses separated from the dies and the dies recycled to die loading and the melt feed step of the process and the process repeated until the desired number of lenses or other optical articles such as compact disk substrates are produced.

대표청구항 ▼

[ Thus, having described the invention, what is claimed is:] [1.] A method of forming an optical article comprising:supplying a rotating turntable having a plurality of spaced die supports for a lower die and an upper die forming an optical article forming die set;rotating the turntable;forming a me

[ Thus, having described the invention, what is claimed is:] [1.] A method of forming an optical article comprising:supplying a rotating turntable having a plurality of spaced die supports for a lower die and an upper die forming an optical article forming die set;rotating the turntable;forming a melt of an optical polymeric material in a melting apparatus and feeding the melt from the apparatus in the form of an unpressurized melt strand;supplying a lower die from a lower die supply device onto one of the die supports;forming and adding a predetermined melt shot portion of the unpressurized melt to the upper surface of the lower die;supplying an upper die from an upper die supply device and positioning the upper die on top of the unpressurized melt forming a melt containing die set comprising, in sequence, a lower die, polymeric material and an upper die;compressing the melt containing die set using a press associated with the die support forming an optical article;releasing the press when the optical article is formed;removing the die set from the rotating turntable;removing the optical article from the die set;recycling the lower die and upper die of the die set to their respective supply devices; andrepeating the above steps until the desired number of optical articles are made.