Method and apparatus providing uniform resin distribution in a coextruded product
US4344907A · kind A · utility
27Cited by
11References
10Claims
0Family size
Assignee
Inventor
Key dates
| Filing date | Oct 30, 1980 |
| Grant date | Aug 17, 1982 |
| Priority date | — |
| Expiry date | Oct 30, 2000 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB29C2948/92876
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
Disclosed is a method and apparatus for ensuring uniform distribution of higher and lower viscosity or flow rate resins in a product produced by a coextrusion process. A flow restriction is provided in the flow path of the lower viscosity or flow rate resin to increase the pressure drop of this resin as it passes through a coextrusion die. The increased pressure drop introduced by the flow restriction causes the lower viscosity or flow rate resin to be more uniformly distributed in the extruded product. A specific die construction providing a uniform resin flow channel within the die is also described.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.