Production of foamed low-density polypropylene by rotational molding
US6103153A · kind A · utility
Inventors
Key dates
| Filing date | Jun 2, 1999 |
| Grant date | Aug 15, 2000 |
| Priority date | — |
| Expiry date | Jun 2, 2019 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2323/12
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Compositions and processing conditions are disclosed for the production by rotomolding of polypropylene foams, hither to satisfactorily produced only by injection molding and extrusion molding. Rheological properties of the polypropylene resin, processing conditions and choice of composition of the chemical blowing agent were found to play important roles in obtaining high quality polypropylene foam structures. High strength fine-cell polypropylene foams could in particular be formed by first melt compounding a suitable chemical blowing agent with the resin under conditions which allow for homogeneous mixing without appreciable decomposition of the blowing agent.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.