Stereolithography using repeated exposures to increase strength and reduce distortion
US4945032A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 31, 1989 |
| Grant date | Jul 31, 1990 |
| Priority date | — |
| Expiry date | Oct 31, 2009 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S430/146
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved stereolithographic process is provided in which the formation of a thin walled three-dimensional object in a reservoir of liquid ultraviolet-curable ethylenically unsaturated material using a support is positioned immediately beneath the upper surface of the liquid reservoir with that upper surface being exposed to ultraviolet light in a pattern to solidify the liquid at and near the upper surface in a series of cross-sections of the desired three-dimensional object, one atop the other. In this way there is formed a series of superposed layers which adhere to one another to build the desired three-dimensional object within the liquid reservoir. The improvement comprises, stopping the exposure at any portion of the surface in the formation of said layers and then repeating the exposure at least once again in the production of each surface layer so that the strength and solvent resistance of the formed object are increased and its distortion is minimized. The ultraviolet exposure of each surface layer is preferably carried out as a series of rapid repeated scans of a computer-directed focused laser.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.