Abstract: An aramid-mica composite insulating nanopaper and a preparation method thereof are disclosed. A mixture of mica and urea is subjected to a solid-phase ball milling, to obtain nano mica modified with amino groups on the surface, which is then assembled with the aramid nanofiber by stepwise suction filtration according to the present disclosure, to form an ordered nanopaper, thereby obtaining an aramid-mica composite insulating nanopaper with ultra-high insulation performances.

Abstract: A measurement apparatus of a moving paper web, includes an optical radiation source that outputs optical radiation toward a scattering element of the measurement apparatus. The scattering element scatters the optical radiation, and a transmitting surface of the scattering element directs the optical radiation in a scattered manner toward the moving paper web. A distance between said transmitting surface of the scattering element and a surface of the paper web is known, and the transmitting surface and a detector of the apparatus are on opposite sides of the paper web. The detector receives at least a part of the optical radiation, which is side-scattered from the moving paper web. The detector determines a moisture value and a dry weight of the paper web on the basis of spectral information on the received optical radiation and the known distance.

Abstract: 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 arami