Dielectric cellular electret film and procedure for its manufacture
AssigneeEmfitech Oy
InventorsKari Kirjavainen, Keijo Korhonen, Jyrki Kroger, Lasse Raisanen
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Abstract
Film of dielectric material, which film contains gas bubbles preferably of a flat shape. To achieve improved electrical properties, the film is given a large internal unipolar charge, which is created by charging the film by means of an electric field intensive enough to produce partial discharges in the gas bubbles and to cause the charges to move into the dielectric material of the film.
Claims21
Dielectric cellular electret film, said cellular film containing flat gas bubbles, wherein the film contains partial discharges inside the film produced in the gas bubbles to achieve improved electrical properties.
Dielectric cellular electret film, said cellular film containing flat gas bubbles,
- wherein the film is a swelled dielectric cellular electret film;
- wherein the film has at least one film layer foamed to be of full-cell type,
- wherein the film has been oriented by strecthing it in two directions, and
- wherein the film contains partial discharges inside the film produced in the gas bubbles to achieve improved electrical properties.
Transducer element having one or several dielectric cellular electret films, said cellular films containing flat gas bubbles, wherein the film contains partial discharges inside the film produced in the gas bubbles to achieve improved electrical properties.
Self-adhesive film self-adhesive by virtue of an electrostatic force consisting of a dielectric cellular electret film, said cellular films containing flat gas bubbles, wherein the film contains partial discharges inside the film produced in the gas bubbles to achieve improved adhesive properties.
Film of dielectric material, self-adhesive by virtue of an electrostatic force, which film contains gas bubbles preferably of a flat shape, characterized in that, to achieve an adhesive quality of the film, the film is given a large internal unipolar charge, which is created by charging the film by means of an electric field intensive enough to produce partial discharges in the gas bubbles and to cause the charges to move into the dielectric material of the film.
Procedure for manufacturing cellular dielectric electret film containing flat gas bubbles, characterized in that, to achieve an improved quality of the film, the film is charged by means of an electric field intensive enough to produce partial discharges in the gas bubbles and to cause the charges to move into the dielectric material of the film, creating a large unipolar charge inside the film.
Dependencies are inferred from the claim text.