Method of injection molding an optical article out of thermoplastic synthetic material
US6790388B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 17, 2001 |
| Grant date | Sep 14, 2004 |
| Priority date | — |
| Expiry date | Dec 21, 2022 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/808
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
For each lens molding cycle, the method comprises the following steps:raising the wall of the mold cavity to a heating temperature higher than or equal to the molding temperature of said material;filling the molding cavity with said material;at the end of filling, increasing the pressure of said material introduced in this way into the molding cavity up to a compacting pressure; andbringing the wall of the molding cavity to a cooling temperature to cool said molded material down to an unmolding temperature below its molding temperature, said cooling temperature being lower than said unmolding temperature.The molding cavity begins to be filled with said material before the heating temperature has been reached. Once both the compacting pressure of said material and the heating temperature of the molding cavity wall have been reached, they are both maintained for a given length of time.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.