Process for preparing composite foamed molded article
US5292465A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Nov 24, 1992 |
| Grant date | Mar 8, 1994 |
| Priority date | — |
| Expiry date | Nov 24, 2012 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2023/12
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A process for preparing a composite foamed molded article according to the invention includes the steps of setting a skin material in the vicinity of an upper mold for stamping-mold kept at a temperature of 10 to 50.degree. C.; feeding a molten polypropylene resin composition for a substrate containing a foaming agent kept at a temperature of not lower than a decomposition temperature of the foaming agent and within the range of 180 to 240.degree. C. onto a surface of a lower mold for stamping-mold kept at a temperature of 30 to 80.degree. C.; closing the mold within 10 seconds after feeding of the composition to clamp the molds at a pressure of 20 to 70 kg/cm.sup.2 ; lifting the upper mold before a thickness of each of hardened layers formed on both surfaces of the composition layer reaches 1.0 mm to open the mold at a distance between the upper mold and lower mold of 1.1 to 2 times of a thickness of a flat portion having neither boss nor rib in the composition layer, thereby to foam the composition; and cooling the foamed substrate layer made of the polypropylene resin composition to harden the substrate layer. The composite foamed molded articles thus obtained is lightweight and…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.