Process for producing moldings from foamed polyolefins
US5618478A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Mar 29, 1996 |
| Grant date | Apr 8, 1997 |
| Priority date | — |
| Expiry date | Mar 29, 2016 |
Classification
- Technology area (CPC C)Chemistry; Metallurgy
- CPC primaryC08J2323/02
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for producing a molding from prefoamed polyolefin particles, involving: shrinking the prefoamed polyolefin particles to a volume of from 30 to 95% of the prefoamed polyolefin particles original volume to provide shrunken particles; treating the shrunken particles at a temperature lying at least 20.degree. C. below the softening temperature of the shrunken particles, in an inert gas atmosphere under a gauge pressure of from 0.2 to 10 bar, for a time sufficient to provide expansion of the shrunken particles upon removal of the pressure; charging the particles into a mold with substantial maintenance of internal pressure of the particles; and foaming the particles, to provide moldings of very low density useful in applications such as packaging and soft upholstering in motor vehicle interiors.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.