Lost foam molding
US6921503B1 · kind B1 · utility
Assignee
Inventor
Key dates
| Filing date | Dec 2, 2002 |
| Grant date | Jul 26, 2005 |
| Priority date | — |
| Expiry date | Jan 2, 2024 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C70/48
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method is provided for molding an article (10) that includes a polymer (100) such as an epoxy resin, reinforced by fibrous material (102) such as fiberglass which is embedded in the polymer material, especially for a hollow article such as a shell. The method includes placing spacers (42, 44) in a mold cavity (30), where the spacers conform closely to the cavity surface and leave a free, or empty volume (64) within themselves. Foamable material (60A) is placed in the free volume and allowed to expand and push the spacers toward the cavity walls while forming a foam core (70) within the spacers. The mold is opened and the spacers and foam core are removed. Next, the foam core is covered with an impervious layer and the fibrous material (72) is wrapped around the foam core. The foam core is placed back in the mold, with the fibrous material spacing the foam core from the walls of the mold. Then, the resin is injected into the mold, into the space (80) between the foam core and the mold walls, to embed the fibrous material in the resin. When the resin hardens, the article formed by fibrous material embedded in resin and the foam core within the article, are removed from the mold, an…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.