Method and apparatus for the production of electret material
US4512940A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Dec 16, 1982 |
| Grant date | Apr 23, 1985 |
| Priority date | — |
| Expiry date | Dec 16, 2002 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01G7/023
- WIPO fieldElectrical machinery, apparatus, energy
- WIPO sectorElectrical engineering
Abstract
An electret material is formed by the method which includes the step of passing a pair of electrical conductor elements along the surface of a dielectric material heated to a predetermined temperature. The conductor elements are supported between a pair of support members driven in a direction to move the conductor elements along the surface of the dielectric material for applying an electrical field to the material. A heating element positioned adjacent the surface of the dielectric material and movable with the conductor element heats an area of the dielectric material located between the conductor elements enabling the material to be polarized by the electrical field, thereby producing an electret.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.