Method for producing polypropylene resin article having skin material lined with foamed layer
US5281376A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 1991 |
| Grant date | Jan 25, 1994 |
| Priority date | — |
| Expiry date | Oct 11, 2011 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C44/381
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A multi-layer molded article which is made of a polypropylene resin body and a skin material lined with a foamed layer and has good appearance is produced by using molds between which a cavity clearance is freely set, placing a skin material lined with a foamed layer between the upper and lower molds and supplying a molten polypropylene resin containing a chemical blowing agent through a resin melt conduit in the lower mold when cavity clearance (t) is between (C+15) mm and (C+50) mm where "C" is a thickness of the skin material lined with the foamed layer, lowering the upper mold at a specific rate and pressing the molten resin at specific pressure to fill cavity ends with the molten resin to complete molding of a body of the resin, pressing the body for a certain time after completing molding to form a skin layer, lifting up the upper mold to decrease a compression pressure of the skin material lined with the foamed layer to a pressure lower than a blowing pressure of the polypropylene resin to form and solidify a foamed body, and again lowering the upper mold to apply a certain pressure on a molded article and cooling the article in the molds.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.