Process for preparing polyolefin foam
US4483809A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jan 14, 1983 |
| Grant date | Nov 20, 1984 |
| Priority date | — |
| Expiry date | Jan 14, 2003 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S264/18
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The present invention relates to a process for preparing a polyolefin foam by heat-molding pre-expanded beads of an expandable polyolefin resin containing a foaming agent in a mold, said process being improved in preparing beads having a peak expansion rate at pre-expansion equal to 1.3 to 3 times the expansion rate of beads to be packed into the mold, adjusting the beads to a pre-expansion rate depending on an expansion rate of the desired foam, and packing and molding the pre-expanded beads in a mold without any further addition of expandability thereto. The polyolefin foam prepared by the process of the present invention is evenly fused to the interior and is less liable to shrink or deform.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.