Optimized flow to prevent core layer breakthrough
US6908581B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jan 31, 2003 |
| Grant date | Jun 21, 2005 |
| Priority date | — |
| Expiry date | Apr 30, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29K2105/253
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A method of co-extruding a plurality of plastic material flowing streams into a mold cavity produces a molded product. Inner and outer streams of covering plastic materials are combined with at least one interior stream that is to serve as an interior core of a resulting molded plastic product. The combined streams are forced to flow along annular flow paths, with the annular interior stream encased within the inner and outer annular covering plastic material stream layers. The flows of the interior stream and the inner and outer streams are controlled so that: the interior stream has a flow velocity that is greater than an average velocity of the combined stream, and the interior stream does not flow along or across a zero-velocity-gradient streamline of the combined streams.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.