Planar heating element and production thereof
OwnerShin Kiyokawa, Shokichi Sakaguchi +1inventors
InventorsShin Kiyokawa, Shokichi Sakaguchi, Toru Takeuchi
Life of this patent
Estimating the term…
Abstract
The present invention is related to a method for producing a planar heating element. The method comprises melt-admixing an insulating thermoplastic resin with an electrically conductive powder. The mixture is then extruded, and the extruded body is rapidly cooled.
Claims8
A method for producing a planar heating element which comprises uniformly melt-admixing an insulating thermoplastic resin with an electrically conductive powder wherein said electrically conductive powder is present in an amount less than 40% by weight of the thermoplastic resin, extruding the mixture to form said planar heating element and immediately cooling the extruded heating element rapidly at a temperature of less than 20.degree. C. whereby the conductive powder is in a higher concentration near the surface of the element.
A method for producing a planar heating element which comprises uniformly melt-admixing an insulating thermoplastic resin with an electrically conductive powder wherein said electrically conductive powder is present in an amount less than 40% by weight of the thermoplastic resin, extruding the melted mixture to form said planar heating element, applying wires lengthwise into the extruded body, stretching or drafting the extruded body in the softening state and immediately continuously rapidly cooling the extruded body at a temperature of less than 20.degree. C. whereby said electrically conductive powder is in a higher concentration near the surface of the element.
Dependencies are inferred from the claim text.