E.i. Dupont De Nemours and Company

Dupont Safety & Construction, Inc.

Roger Curtis Wicks

Mikhail R Levit

Serge Rebouillat

Bruce A Yost

Peter J Hollberg

Xun Ma

Radoslaw Szewczyk

Chris Dembrosky

Brian P Little

Jean Claude Duart

Brian Keith Trask

Brian Paul Little

Peter John Hollberg

An aramid paper suitable for use as electrical insulation comprising a first outer layer and a second outer layer, each of which comprising 70 to 30 weight percent aramid floc and 30 to 70 weight percent aramid fibrids, and each of which being free of mica and having a first face and a second face; an inner layer comprising 50 to 70 weight percent aramid material and 30 to 50 weight percent mica and having a first face and a second face; wherein the first face of the first outer layer is a first outer face of the aramid paper, and the second face of the first outer layer is coextensive with and bound face-to-face with the first face of the inner layer solely by fibrids in the first outer layer and the inner layer; and wherein the first face of the second outer layer is coextensive with and bound face-to-face with the second face of the inner layer solely by fibrids in the second outer layer and the inner layer, and the second face of the second outer layer is a second outer face of the aramid paper; the aramid paper having a total of 25 to 40 weight percent mica.

Low-shedding aramid paper containing mica

Laminate structure suitable as electrical insulation comprising a mica-aramid layer of 35-55 wt % mica, 20-60 wt % binder, and 5 to 25 wt % aramid floc, the mica distributed uniformly in the mica-aramid layer; and an aramid layer comprising 35-75 wt % binder and 25-65 wt % aramid floc, the aramid layer being essentially free of mica; wherein the mica-aramid layer has a limiting oxygen index (LOI) of 37% or greater, and the aramid layer has a LOI of 30% or less and having a tensile strength and elongation greater than the mica-aramid layer; and the mica-aramid layer being homogeneously and continuously bound to the aramid layer; the laminate structure having a thickness of at least 0.10 mm, a LOI greater than 32%, and when exposed to a flame to determine LOI, the laminate burns as one piece.

High limiting oxygen index electrical insulation laminates

This invention relates to a laminate electrical insulation part for an electrical device comprising a thermoplastic film positioned between, adjacent to, and attached to two nonwoven sheets. Each of the nonwoven sheets consists of multicomponent polymeric fibers comprising at least a first polymer and a second polymer, the first polymer having a melting point that is at least 15 degrees Celsius lower than both the melting point of the second polymer and the melting point of the thermoplastic film, and the film is attached to the nonwoven sheets by the first polymer in the nonwoven sheets. The electrical insulation part has a breakdown voltage of at least 3 kilovolts, and a surface having a dynamic frictional coefficient of 0.25 or less. This invention also relates to an electrical device component comprising the laminate electrical insulation part.

Laminate electrical insulation part

Growing community of inventors

South Chesterfield, VA, United States of America

Roger Curtis Wicks