A nonwoven sheet material comprising a substrate and an applied fibril covering on said substrate, and process for making same, wherein the substrate is a paper, a spunbonded fibrous sheet, or a fibrous or non-fibrous membrane, and wherein the applied fibril covering comprises fibrils having a diameter of 1 to 5000 nanometers, a length of 0.2 to 3 millimeters, a specific surface area of 3 to 40 square meters/gram, and a Canadian Standard Freeness of 0 to 10 milliliters, the fibrils comprising an aramid polymer.

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.

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.

Paper with a grammage of 10-100 g/m.sup.2 including at least 20 wt. % of microfilaments and at least 20 wt. % of a non-resinous binder, the microfilaments having an average filament length in the range of 2-25 mm and titer less than 1.3 dtex, the non-resinous binder comprising at least one of fibrid or pulp. The paper shows high strength and other attractive properties.

Paper with a grammage of 10-100 g/m.sup.2 including at least 20 wt. % of microfilaments and at least 20 wt. % of a non-resinous binder, the microfilaments having an average filament length in the range of 2-25 mm and titer less than 1.3 dtex, the non-resinous binder comprising at least one of fibrid or pulp. The paper shows high strength and other attractive properties.

An aramid-based paper comprising at least 90 wt. % of aramid material, the aramid material including at least one of aramid shortcut and aramid fibrid, the paper including at most 40 wt. % aramid pulp, calculated on the total amount of aramid material, wherein the paper includes 0.1-10 wt. % of polyamido-amine epichlorohydrin (PAE). It has been found that the incorporation of 0.1-10 wt. % of polyamido-amine epichlorohydrin (PAE) into an aramid-based paper including at least 90 wt. % of aramid material calculated on the weight of the paper not including the PAE, the aramid material including at least one of aramid shortcut and aramid fibrid, the paper including at most 40 wt. % aramid pulp, leads to a surprising improvement of the z-strength and the tear strength of the paper.

An aramid-based paper comprising at least 90 wt. % of aramid material, the aramid material including at least one of aramid shortcut and aramid fibrid, the paper including at most 40 wt. % aramid pulp, calculated on the total amount of aramid material, wherein the paper includes 0.1-10 wt. % of polyamido-amine epichlorohydrin (PAE). It has been found that the incorporation of 0.1-10 wt. % of polyamido-amine epichlorohydrin (PAE) into an aramid-based paper including at least 90 wt. % of aramid material calculated on the weight of the paper not including the PAE, the aramid material including at least one of aramid shortcut and aramid fibrid, the paper including at most 40 wt. % aramid pulp, leads to a surprising improvement of the z-strength and the tear strength of the paper.

The invention relates to a method for the manufacture of thermoplastic fibrous materials comprising forming at least one foamed liquid comprising water and at least one foaming agent, forming a dispersion by dispersing fibers including long fibers in said at least one foamed liquid comprising water and at least one foaming agent, mixing the dispersion with a foamable liquid or dispersion comprising at least one thermoplastic polymer, forming at least one foamed dispersion, and conveying the foamed dispersion or dispersions to a foraminous support and draining liquid trough the foraminous support to form a web or a sheet, to obtain the thermoplastic fibrous material. The invention also relates to materials and products obtainable by the method, and uses related thereto.

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.

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.