Apparatus for throttle-valving control for the co-extrusion of plastic materials as interior core streams encased by outer and inner streams for molding and the like
US5914138A · kind A · utility
60Cited by
5References
16Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Sep 27, 1996 |
| Grant date | Jun 22, 1999 |
| Priority date | — |
| Expiry date | Sep 27, 2016 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2045/1614
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A multiple-plastic stream co-extruder as for injection-molding cavities, in which the extruder is internally provided therewithin and therealong with a restrictor or throttle pin, rod or element that forces combined plastic material streams, formed with an interior core stream encased in outer and inner stream layers, into corresponding concentric annular flow stream layers that are ultimately split transversely in opposite directions into a cavity gated to the extruder, and with the core stream at a region of zero gradient in the transverse flow velocity profile within the extruder and cavity.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.