Shaped body of extruded acrylic glass
US4278723A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 4, 1979 |
| Grant date | Jul 14, 1981 |
| Priority date | — |
| Expiry date | Dec 4, 1999 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/24777
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A shaped acrylic glass body is provided which has a reshaped inner zone outside the plane of the border or edge region and which is characterized by excellent resistance to weather and to chemical corrosion. The shaped body is manufactured from an extruded plate of a polymer or copolymer containing at least 80% by weight of polymethylmethacrylate or a copolymer of methyl methacrylate. The extruded plate is subjected to biaxial stretching, by at least about 25% in each direction and, while the edges or border regions are gripped to maintain their dimensions, a force is applied to the interior portion of the plate while it is in a thermoelastic state to move the interior portion out of the plane of the surrounding edges.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.