Process for the production of shaped plastic elements
US4818465A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Apr 12, 1988 |
| Grant date | Apr 4, 1989 |
| Priority date | — |
| Expiry date | Apr 12, 2008 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29L2031/3005
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A deep drawing molding process for the formation of shaped plastic elements in which a certain thickness of the thermoplastic sheet to be formed is heated to the plastic flow state while an embossed or decorated outer side of the sheet is maintained at a temperature below the plastic state by means of a cooling air stream. The plastic element producted has an undamaged decorated side and improved wear properties such that it may be used in high ambient temperature applications, such as automobile dashboards, without cracking. The apparatus for heating and forming the plastic element includes a clamping frame to hold the sheet, a heating element disposed above the sheet, a molding box below the frame, which box is provided with inlets and outlets for cooling air and the application of vacuum, and a moldign tool also disposed above said frame, which is forced through said frame and against said sheet when a certain thickness of the sheet has been heated to the desired plastic flow temperature.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.