Polypropylene foam sheets
US5149579A · kind A · utility
57Cited by
9References
8Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Dec 11, 1991 |
| Grant date | Sep 22, 1992 |
| Priority date | — |
| Expiry date | Dec 11, 2011 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249992
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A thermoformable, rigid or semi-rigid polypropylene foam sheet having a smooth surface and a uniform cell structure and a density of at least 2.5 lbs/ft.sup.3 is prepared by extruding a mixture of a nucleating agent, a physical blowing agent and a polypropylene resin having a high melt strength and high melt elasticity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.