Dies for extrusion moulding
US5733580A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 28, 1996 |
| Grant date | Mar 31, 1998 |
| Priority date | — |
| Expiry date | Feb 28, 2016 |
Classification
- Technology area (CPC Y)Emerging Cross-Sectional Technologies
- CPC primaryY10S425/033
- WIPO fieldOther special machines
- WIPO sectorMechanical engineering
Abstract
A die for extrusion molding a resin bonding magnet. In the production of the magnet, a molten mixture of a magnetic powder and a resin are introduced into a cavity between an outer die and a mandril to which a magnetic field is applied. A steep temperature gradient along the die axis direction of the molten mixture and the cavity is achieved by making the outer die of a multiple layer structure along the die axis direction, utilizing two or more axially adjacent blocks or sheets made of the same or different materials whereby fluidity of the molten mixture is sufficiently high at the inlet of the cavity to enable the magnetic powder in the molten mixture to be sufficiently orientated in the direction of the magnetic field and then the molten mixture is cooled to a solidified state so that the orientation of the magnetic powder is not disturbed, thereby producing a magnetic having high magnetic properties.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.