Powder slush process for making plastic articles
US4740337A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 27, 1986 |
| Grant date | Apr 26, 1988 |
| Priority date | — |
| Expiry date | May 27, 2006 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/039
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
The plastic molded article is produced by heating a mold by contact with a preheated salt bath. The salt bath is readily maintained at a uniform temperature and is self-insulating for energy efficiency. A noncontact infrared sensor monitors the mold cavity temperature while in the salt bath, and the mold is removed from the bath when the proper mold temperature is reached. A charge of plastic powder is introduced into the mold by clamping the mold to a powder slush box with the mold cavity confronting the opening of the box. The mold and box are then simultaneously rotated to pour the plastic charge into the mold. The plastic charge forms a skin on the cavity surface and additional plastic material may be built up to provide additional thickness. The mold and box are then separated; the mold is then postcured and cooled, whereupon the finished article may be removed from the mold.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.