Polystyrene foam and a process for making the same
US5340844A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Apr 24, 1992 |
| Grant date | Aug 23, 1994 |
| Priority date | — |
| Expiry date | Apr 24, 2012 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S521/908
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
An improved polystyrene foam having less corrugation is disclosed which uses carbon dioxide as the blowing agent and 1-30 weight percent endothermic agent, such as water, with the weight based on the total carbon dioxide blowing agent and endothermic agent weight. This combination of carbon dioxide and endothermic agent decreases the corrugation of the thermoplastic foam, while just slightly increasing density, when the process parameters, including throughput, are equivalent to using only carbon dioxide. The process an also allow an increased foaming temperature and greater process throughput of an equivalent density thermoplastic foam at approximately equivalent corrugation levels when compared to the use of only using only carbon dioxide.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.