The present invention provides an aramid nanofiber (ANF)-based insulation paper and a preparation method thereof, and relates to the technical field of composite insulation material. The ANF-based insulation paper provided in the present invention includes ANFs and inorganic insulation materials. The ANFs have a bifurcated geometry and form a three-dimensional network structure, and the inorganic insulation materials are distributed in the three-dimensional network structure. The ANF paper provided in the present invention, with optimal electrical and mechanical properties and excellent insulation and flame-resistance, can replace mica tapes, aramid papers and aramid mica papers on the current market for insulation, and thus the thickness for insulation can be reduced. The present invention provides a method for preparing the ANF-based insulation paper. The preparation method provided in the present invention is simple, has excellent operability, and can be used for continuous preparation, thereby facilitating the realization of industrial production.

The disclosure relates to a curable mixture for use in impregnation of paper bushings comprising a resin mixture of a bisphenol-A-diglycidylether (BADGE) and a bisphenol-F-diglycidylether (BFDGE), methyltetrahydrophthalic anhydride (MTHPA) as hardener, and an accelerator selected from the group consisting of tertiary alkylamine aminoethylalcohols and corresponding ethers thereof as well as paper bushings impregnated with such mixture and uses of such mixture.

The disclosure relates to a curable mixture for use in impregnation of paper bushings comprising a resin mixture of a bisphenol-A-diglycidylether (BADGE) and a bisphenol-F-diglycidylether (BFDGE), methyltetrahydrophthalic anhydride (MTHPA) as hardener, and an accelerator selected from the group consisting of tertiary alkylamine aminoethylalcohols and corresponding ethers thereof as well as paper bushings impregnated with such mixture and uses of such mixture.

A separator for electrochemical elements includes beaten solvent-spun cellulose fibers and rayon fibers having a fiber diameter of 9.5 m or less. More preferably, the separator for electrochemical elements has a content of the rayon fibers relative to all fibers of 10 to 25% by mass, and can be applied to electrochemical elements such as electric double layer capacitors, hybrid capacitors, redox capacitors, and lithium secondary batteries. The separator can provide low internal short circuit failure rates and high surface strength.

The present invention is related to a method of diagnosing an oil-immersed electrical apparatus by an assessment of a state of deterioration of the oil-immersed electrical apparatus, in which the oil-immersed electrical apparatus includes an insulating oil and an insulating paper and the insulating paper contains an amine compound. This method includes performing a quantitative analysis of a marker substance contained in the insulating oil and assessing a state of deterioration of the oil-immersed electrical apparatus based on a quantified value of the marker substance obtained by the quantitative analysis. The marker substance is a degradation product of cellulose, and this degradation product of cellulose does not chemically react with a deterioration product of the amine compound.

A corona shielding paper for use in a corona shielding system for an electric machine, e.g. a high-voltage machine, may be produced by compacting partial discharge-resistant, planar, conductive particles but can include both reinforcement fibers and a woven fabric.

A corona shielding paper for use in a corona shielding system for an electric machine, e.g. a high-voltage machine, may be produced by compacting partial discharge-resistant, planar, conductive particles but can include both reinforcement fibers and a woven fabric.

Aspects of the subject disclosure may include, a system that guides electromagnetic waves that propagate along a transmission medium without requiring an electrical return path, and at least reduces radiation on an outer surface of a structure reducing a flow of an electrical current from an inner surface of the structure to the outer surface of the structure. Other embodiments are disclosed.

In order to provide electrical insulating paper and an electrical insulating sheet including the same which exhibit excellent dielectric breakdown strength, excellent hygroscopic dimensional stability and thermal dimensional stability, and excellent tear strength and wear durability, a nonwoven fabric is fabricated wherein the fabric is a wet nonwoven fabric containing a meta-aramid fiber and a polyphenylene sulfide short fiber and a proportion of the polyphenylene sulfide short fiber at least partially fused in the wet nonwoven fabric is 40% or less, and the wet nonwoven fabric has a dielectric breakdown strength of 17 kV/mm or more.

In order to provide electrical insulating paper and an electrical insulating sheet including the same which exhibit excellent dielectric breakdown strength, excellent hygroscopic dimensional stability and thermal dimensional stability, and excellent tear strength and wear durability, a nonwoven fabric is fabricated wherein the fabric is a wet nonwoven fabric containing a meta-aramid fiber and a polyphenylene sulfide short fiber and a proportion of the polyphenylene sulfide short fiber at least partially fused in the wet nonwoven fabric is 40% or less, and the wet nonwoven fabric has a dielectric breakdown strength of 17 kV/mm or more.