Method of manufacturing thin dielectric materials for high potential work

April 9, 1935. a. meissner 1,997,263

METHOD OF MANUFACTURING THIN DIELECTRIC MATERIALS FOR HIGH POTENTIAL WORK Filed July 3, 1929

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-o+

BY

INVENTOR

ALEXANDER MEISSNER

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ATTORNEY

Patented Apr. 9, 1935

1,997,263

UNITED STATES PATENT OFFICE

1,997,263

METHOD OF MANUFACTURING THIN DIELECTRIC MATERIALS FOB HIGH POTENTIAL WORK

Alexander Meissner, Berlin, Germany, assignor to Telefunken Gesellschaft fiir Drahtlose Telegraphic m. b. H., Berlin, Germany, a corporation of Germany

Application July 3, 1929, Serial No. 375,891 In Germany July 4,1928

Claims.

The present invention relates generally to an improved method of manufacturing insulation materials.

More specifically the present invention is di5 rected toward a system of manufacturing relatively thin insulation materials by subjecting the insulation material while in a molten or soft state during its manufacture to the action of an electrical field.

Considerable experimentation has shown that insulation materials can be improved a great deal by subjecting the material during its manufacture, that is, while it is still in a soft or liquid state to a powerful electrical field and allowing the material to solidify or consolidate in the presence of such an electrical field. The electrical field may be obtained, for instance, by applying, electrodes on one or both faces of the insulation material while it is solidified. Across the 20 two electrodes a potential ranging between 1 and 10,000 volts is applied depending upon the thickness of the dielectric material. Of course, these values given are here included simply for illustration and it is to be distinctly understood that any voltage commensurate with the thickness of the dielectric material may be employed. While I do not desire to hold myself to any particular explanation of the phenomena involved I believe that the reason why dielectrics treated in ac30 cordance with my invention are greatly improved is because if the dielectric material is still soft or liquid, that is, not yet solidified then by the action of such a strong electrical field very strong forces are brought to act upon the insulating _or dielectric material. One possible explanation of this is that by the action of such a field and the electrodes all the air bubbles or cavities and impurities in the electric substance are forced away from the electrodes. That this is so is shown by the fact that if a dielectric substance or insulation material has been treated in the manner set forth above and if it is fractured or cut and the fracture examined it will be found that a considerably greater density and concentration and more uniform disposition of the constituent , particles of the dielectric are produced at the electrodes. In the case of thin layers or coats it will be found sufficient to apply only a unilateral field. I have also found that in the case of thick 50 layers concentration or compacting of the ma.

terial in the vicinity of the. electrodes may be insured most suitably while the layers are being rolled or pressed as the case may be. For this purpose the rolling cylinders or pressing members ⁵⁵ are furnished with potential at one or both sides.

(CL 204—31)

The single figure in the drawing shows by way of example one method by which my invention may be practiced. In said figure a mold is shown comprising a matrix I and a patrix 2 with metallic coats 3 and 4. To the metallic coats 3 and 4 r there is applied a potential of the desired in- ° tensity by way of supply leads 5 and 6. In the drawing 1 represents in a general way the mass of insulation material which is to be molded pressed, or rolled as the case may be. ,θ

If thin layers are manufactured and must be made serviceable also for relatively high potentials then a plurality of thin layers manufactured as here directed are superposed or else they may be made by Inserting a metal foil or a metal- , lized deposit on the material and using this metal ‘ foil or deposit as an electrode for the next layer to be produced. It should here be noted that the present method of constructing insulating materials is particularly useful .in the manufac- o₀ture of insulated wires. In such cases the insulation while still in a molten state and while hardening on the wire may be subjected to the action of a powerful electrical field with the result that the insulation material is pressed with 05 great force against the metal surface of the wire.

Throughout this specification and claims which are to follow I Intend to use' the term “insulation material” generically and intend that it cover such materials as bakelite, glass, norce- -o lain, rubber, etc. -.,