A nanofiber nonwoven product is disclosed which comprises a polyamide with a relative viscosity from 2 to 330, spun into nanofibers with an average diameter of less than 1000 nanometers (1 micron). In general, the inventive products are prepared by: (a) providing a polyamide composition, wherein the polyamide has a relative viscosity from 2 to 330; (b) melt spinning the polyamide composition into a plurality of nanofibers having an average fiber diameter of less than 1 micron, followed by (c) forming the nanofibers into the product.

A water vapour-permeable and hot water-resistant paper made substantially of cellulose and of manufacturing additives required for cellulose production, such as pH-value adjusting agents based on acids and/or bases, the paper exclusively contains cellulose with fibre lengths of at least 2.0 mm as a length-weighted mean, in particular of at least 2.5 mm as a length-weighted mean, wherein the cellulose forming the paper is a cellulose ground to a consistency of 30-35% by high-consistency grinding and possibly to a consistency of 4-6% by low-consistency grinding, a proportion of fines in the paper is set at values smaller than 6.5% and the pH value is set in the pseudo-neutral range, in particular at values under 7.5, preferably at values between 6.6 and 7.4, and an elongation of the paper in the machine direction is ≤3%.

A water vapour-permeable and hot water-resistant paper made substantially of cellulose and of manufacturing additives required for cellulose production, such as pH-value adjusting agents based on acids and/or bases, the paper exclusively contains cellulose with fibre lengths of at least 2.0 mm as a length-weighted mean, in particular of at least 2.5 mm as a length-weighted mean, wherein the cellulose forming the paper is a cellulose ground to a consistency of 30-35% by high-consistency grinding and possibly to a consistency of 4-6% by low-consistency grinding, a proportion of fines in the paper is set at values smaller than 6.5% and the pH value is set in the pseudo-neutral range, in particular at values under 7.5, preferably at values between 6.6 and 7.4, and an elongation of the paper in the machine direction is ≤3%.

The present application relates generally to filter media useful for manufacturing air filters for residential and commercial office's Heating, Ventilation, and Air Conditioning (HVAC), particularly to filters and filter media comprising soybean-based materials. The present invention provides an inexpensive, effective, environmentally friendly, and sustainable media for manufacturing HVAC air filters for residential and commercial buildings.

The present application relates generally to filter media useful for manufacturing air filters for residential and commercial office's Heating, Ventilation, and Air Conditioning (HVAC), particularly to filters and filter media comprising soybean-based materials. The present invention provides an inexpensive, effective, environmentally friendly, and sustainable media for manufacturing HVAC air filters for residential and commercial buildings.

A container and a preparation method thereof are provided. A material forming the container includes at least two types of oxidized nanocelluloses interlaced with each other, the at least two types of oxidized nanocelluloses being configured to have different degrees of expansion after absorbing moisture in a same environment. In a dry condition, the at least two types of oxidized nanocelluloses do not expand, so the structure of the container is relatively dense and the air permeability is poor, which can sufficiently maintain moisture of an article stored in the container. In case the article itself or other reasons cause high humidity, different oxidized nanocelluloses of the container expand after absorbing moisture, so that gaps between different oxidized nanocelluloses becomes larger, and the air permeability of the container becomes better, which can discharge excessive moisture, enabling the container to self-adjust the air permeability based on humidity.

The invention relates to a filtering material permeable to air and impermeable to oral, nasal and/or ocular human liquid aqueous excretions, comprising at least one bundle, referred to as a hydrophobic bundle, of at least two hydrophobic sheets which are superimposed and each formed by porous paper, having a gsm substance less than 30 g/m.sup.2, each hydrophobic sheet being formed by cellulose fibres, referred to as cross-linked cellulose fibres, which are connected to each other by hydrogen bonds and by covalent bonds which are formed with at least one group of cross-linking atoms, characterised in that at least some of the hydroxyls of the cross-linked cellulose fibres which are not engaged in hydrogen bonds and which are accessible to the gases form a covalent bond with an acyl group with a hydrophobic chain.

The invention relates to a filtering material permeable to air and impermeable to oral, nasal and/or ocular human liquid aqueous excretions, comprising at least one bundle, referred to as a hydrophobic bundle, of at least two hydrophobic sheets which are superimposed and each formed by porous paper, having a gsm substance less than 30 g/m.sup.2, each hydrophobic sheet being formed by cellulose fibres, referred to as cross-linked cellulose fibres, which are connected to each other by hydrogen bonds and by covalent bonds which are formed with at least one group of cross-linking atoms, characterised in that at least some of the hydroxyls of the cross-linked cellulose fibres which are not engaged in hydrogen bonds and which are accessible to the gases form a covalent bond with an acyl group with a hydrophobic chain.

In the porous substrate loaded with porous nano-particles structure and one-step micro-plasma production method thereof, since the micro-plasma system enhances the electron density and promotes reaction speed in the reaction without generating thermal effect, the method may be performed at an atmosphere environment. The nano-particles also can be quickly obtained by aforementioned micro-plasma system. The electromagnetic field generated by the micro-plasma can drive the nano-particles to be loaded onto the porous substrate in a one step, rapid and low cost process to improve the conventional techniques which require a relatively long procedure time and a complicated process.

In the porous substrate loaded with porous nano-particles structure and one-step micro-plasma production method thereof, since the micro-plasma system enhances the electron density and promotes reaction speed in the reaction without generating thermal effect, the method may be performed at an atmosphere environment. The nano-particles also can be quickly obtained by aforementioned micro-plasma system. The electromagnetic field generated by the micro-plasma can drive the nano-particles to be loaded onto the porous substrate in a one step, rapid and low cost process to improve the conventional techniques which require a relatively long procedure time and a complicated process.