Method of forming dimensionally stable foamed articles of polyvinyl aromatic resins and resultant product
US4125490A · kind A · utility
Inventor
Key dates
| Filing date | Apr 6, 1976 |
| Grant date | Nov 14, 1978 |
| Priority date | — |
| Expiry date | Apr 6, 1996 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/83
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A rigid, dimentionally stable, distortion-free article of foamed polyvinyl aromatic resin, having a solid outer skin, is formed by incorporating in a foamable polyvinyl aromatic resin a finely, divided inert solid that has been surface treated to render the solid hydrophobic and then molding the foamable composition under foaming conditions. Foamed polyvinyl aromatic resin articles molded in accordance with the present invention have physical dimensions capable of meeting tolerances in the order of .+-. 0.002 inches and are suitable for use in the manufacture of precision measuring devices and, particularly, frames for level instruments.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.