Thermoformable multi-layer polypropylene foam sheet
US6773796B1 · kind B1 · utility
3Cited by
7References
9Claims
0Family size
Assignee
Inventors
Key dates
| Filing date | Jul 2, 2001 |
| Grant date | Aug 10, 2004 |
| Priority date | — |
| Expiry date | Jul 2, 2021 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10T428/249993
- WIPO fieldSurface technology, coating
- WIPO sectorChemistry
Abstract
A thermoformable, multilayer, co-extruded sheet comprising at least two separate foam polypropylene layers obtained by chemical foaming of two polyproplene resins having different flexural modulus, a “high modulus” polypropylene and a “low modulus” polypropylene. The presence of two different foam layers of polypropylene of different modulus allows obtaining a thermoformable sheet with the desired balance between thermoformability and stiffness.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.