Extrusion-compression molding of optical articles

Abstract

An extrusion-compression molding process is provided for making optical articles wherein a melt shot of optical polymer extrudate is fed to sequentially moving lower dies of a die set including a lower die and an upper die and then the upper die positioned on top of the melt shot containing lower die and the die set compressed forming the optical article. After the optical article is formed, the lower die and upper die are separated and recycled for forming additional optical articles. The optical polymeric material may be in the form of pellets and melted in an extruder. A reaction extruder may also be employed where the optical polymeric material is produced in the reaction extruder from optical polymer monomers. A shuttle carriage is preferably used to transport the lower die, melt shot containing lower die and melt shot containing die set through the steps of the molding process. A control system is used to obtain input data and generate output signals to monitor and control the process steps.

Dependencies are inferred from the claim text.