Foam and method of making
US7094463B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Dec 30, 2002 |
| Grant date | Aug 22, 2006 |
| Priority date | — |
| Expiry date | Jun 8, 2023 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249992
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention is directed to a process for producing a polypropylene foam by mixing a high melt strength polypropylene and a blowing agent to form a melt mixture, reducing the temperature of the melt mixture at the exit of the apparatus to an exit temperature that is no more than 30° C. above the melt temperature of the neat polypropylene while maintaining the melt mixture at a pressure sufficient to prevent foaming; passing the mixture through said exit shaping orifice and exposing the mixture to atmospheric pressure, whereby the blowing agent expands causing cell formation resulting in foam formation, and orienting said foam. The foam is useful as tape backings, thermal and acoustical insulation and as a diffuse reflector for use in optical applications such as computer displays.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.