A device for producing nanofibers or microfibers from solutions, emulsions, liquid suspensions or melts containing a spun substance, comprises a chamber in which a hollow shaft is assembled, on which at least one rotating disc with an output gap is mounted, The chamber is generally provided with a source of the flowing gas and a collection area. In an alternative embodiment, the chamber is provided with a number of side by side arranged hollow shafts.

It is preferred that at least one hollow shaft is provided with two superposed rotating discs. At least one rotating disc is composed of two successive parts, wherein between the upper part and the lower part an outlet gap is formed around the circumference thereof. The size of the outlet gap between the upper part and the lower part of rotating disc may be formed by a spacer element, in particular a spacer ring.

A device for producing nanofibers or microfibers from solutions, emulsions, liquid suspensions or melts containing a spun substance, comprises a chamber in which a hollow shaft is assembled, on which at least one rotating disc with an output gap is mounted, The chamber is generally provided with a source of the flowing gas and a collection area. In an alternative embodiment, the chamber is provided with a number of side by side arranged hollow shafts.

It is preferred that at least one hollow shaft is provided with two superposed rotating discs. At least one rotating disc is composed of two successive parts, wherein between the upper part and the lower part an outlet gap is formed around the circumference thereof. The size of the outlet gap between the upper part and the lower part of rotating disc may be formed by a spacer element, in particular a spacer ring.

Described herein are nanofibers and methods for making nanofibers that include any one or more of (a) a non-homogeneous charge density; (b) a plurality of regions of high charge density; and/or (c) charged nanoparticles or chargeable nanoparticles. In one aspect, the present invention fulfills a need for filtration media that are capable of both high performance (e.g., removal of particle sizes between 0.1 and 0.5 μm) with a low pressure drop, however the invention is not limited in this regard.

Described herein are nanofibers and methods for making nanofibers that include any one or more of (a) a non-homogeneous charge density; (b) a plurality of regions of high charge density; and/or (c) charged nanoparticles or chargeable nanoparticles. In one aspect, the present invention fulfills a need for filtration media that are capable of both high performance (e.g., removal of particle sizes between 0.1 and 0.5 μm) with a low pressure drop, however the invention is not limited in this regard.

Processes for making fibrous structures and more particularly processes for making fibrous structures comprising filaments are provided.

A method for preparing an anti-bacterial and anti-ultraviolet multifunctional chemical fiber includes: dissolving several soluble metal salts and a polymer complexing dispersant into water to prepare an aqueous solution; adding into a polymer monomer; reacting under microwave or hydrothermal action to obtain a polymer monomer containing multifunctional nano oxides; adding the polymer monomer with other monomer, catalyst, initiator, stabilizer, and the like into a polymerization reactor; and carrying out esterification, polycondensation or copolymerization to obtain a polymer melt, and carrying out spinning or ribbon casting and granule cutting to obtain an anti-bacterial and anti-ultraviolet multifunctional chemical fiber or masterbatch chips. By generating nano metal oxides in the monomer in situ before the polymerization reaction, small particle sizes and dispersibility of the nano metal oxide are ensured; the chemical fiber has efficient, durable antibacterial and anti-ultraviolet functions and is free of metal ion precipitation.

A method for preparing an anti-bacterial and anti-ultraviolet multifunctional chemical fiber includes: dissolving several soluble metal salts and a polymer complexing dispersant into water to prepare an aqueous solution; adding into a polymer monomer; reacting under microwave or hydrothermal action to obtain a polymer monomer containing multifunctional nano oxides; adding the polymer monomer with other monomer, catalyst, initiator, stabilizer, and the like into a polymerization reactor; and carrying out esterification, polycondensation or copolymerization to obtain a polymer melt, and carrying out spinning or ribbon casting and granule cutting to obtain an anti-bacterial and anti-ultraviolet multifunctional chemical fiber or masterbatch chips. By generating nano metal oxides in the monomer in situ before the polymerization reaction, small particle sizes and dispersibility of the nano metal oxide are ensured; the chemical fiber has efficient, durable antibacterial and anti-ultraviolet functions and is free of metal ion precipitation.

The invention provides an antimicrobial fiber which exhibits excellent antimicrobial properties even without the addition of antimicrobial agents and can remain antimicrobial even after repeated washing. The antimicrobial fiber comprises a fiber having on a surface thereof a polyacetal copolymer (X) containing oxyalkylene groups, the molar amount of oxyalkylene groups in the polyacetal copolymer (X) being 0.2 to 5 mol % relative to the total of the molar amount of oxymethylene groups and the molar amount of oxyalkylene groups.

The invention provides an antimicrobial fiber which exhibits excellent antimicrobial properties even without the addition of antimicrobial agents and can remain antimicrobial even after repeated washing. The antimicrobial fiber comprises a fiber having on a surface thereof a polyacetal copolymer (X) containing oxyalkylene groups, the molar amount of oxyalkylene groups in the polyacetal copolymer (X) being 0.2 to 5 mol % relative to the total of the molar amount of oxymethylene groups and the molar amount of oxyalkylene groups.

A composite sheet comprising two or more layers is described where the degree of abrasiveness of can be controlled. The sheet can comprise partially or wholly biodegradable or compostable materials or blends thereof. Methods of preparing the composite sheets are also described.