Extrusion-compression molding of optical articles
US6015512A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 28, 1998 |
| Grant date | Jan 18, 2000 |
| Priority date | — |
| Expiry date | Jan 28, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/808
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.