Continuous extrusion-compression molding process for making optical articles
US6042754A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 30, 1998 |
| Grant date | Mar 28, 2000 |
| Priority date | — |
| Expiry date | Oct 30, 2018 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/808
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
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.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.