The present invention intends to provide an acid type carboxylated cellulose nanofiber having a high viscosity in a low shear region, or to provide an acid type carboxylated cellulose nanofiber having a very short fiber length, and the acid type carboxylated cellulose nanofiber has a carboxy group at least in part of a constituent unit constituting a cellulose molecular chain, wherein a viscosity of water dispersion with a content from 0.95 to 1.05% by mass is 400 Pa.Math.s or higher at a shear velocity from 0.003 to 0.01 s.sup.−1 at 30° C., or an average fiber length is from 50 to 500 nm and a ratio of fibers having a fiber length of 300 nm or shorter is 50% or higher.

The present invention intends to provide an acid type carboxylated cellulose nanofiber having a high viscosity in a low shear region, or to provide an acid type carboxylated cellulose nanofiber having a very short fiber length, and the acid type carboxylated cellulose nanofiber has a carboxy group at least in part of a constituent unit constituting a cellulose molecular chain, wherein a viscosity of water dispersion with a content from 0.95 to 1.05% by mass is 400 Pa.Math.s or higher at a shear velocity from 0.003 to 0.01 s.sup.−1 at 30° C., or an average fiber length is from 50 to 500 nm and a ratio of fibers having a fiber length of 300 nm or shorter is 50% or higher.

According to an example aspect of the present invention, there is provided a melt spinning method of cellulose based fibers with controlled molar masses and different side lengths, and continuous melt spun cellulose fibers thereof.

According to an example aspect of the present invention, there is provided a melt spinning method of cellulose based fibers with controlled molar masses and different side lengths, and continuous melt spun cellulose fibers thereof.

A fiber blend containing: (a) a cellulose acetate (CA) staple fibers having a denier per filament (DPF) of 3.0 or less; and (b) structural staple fibers having a dpf of 6.0 or more; and (c) optionally binder fibers. The fiber blend can be made into nonwoven webs for heat-bonding and subsequent use as thermal insulation in, e.g., outerwear, bedding, etc. The fiber blend can now contain sustainably derived fibers, optionally biodegradable, that provide good thermal insulation clo values and loft even after multiple wash cycles along with good short term compression recovery.

A fiber blend containing: (a) a cellulose acetate (CA) staple fibers having a denier per filament (DPF) of 3.0 or less; and (b) structural staple fibers having a dpf of 6.0 or more; and (c) optionally binder fibers. The fiber blend can be made into nonwoven webs for heat-bonding and subsequent use as thermal insulation in, e.g., outerwear, bedding, etc. The fiber blend can now contain sustainably derived fibers, optionally biodegradable, that provide good thermal insulation clo values and loft even after multiple wash cycles along with good short term compression recovery.

The invention relates to a filter material and/or filler material for mouthpieces for use with smoking products or HNB products, the filter material and/or filler material being based on cellulose acetate filaments, at least parts of which are in the form of hollow cellulose acetate filaments. The invention also relates to a mouthpiece for use with smoking products or HNB products, the mouthpiece comprising a filter material and/or filler material of the type according to the invention. The invention also relates to a cigarette filter comprising such a filter material and/or filler material, and to a corresponding method for manufacturing a filter material and/or filler material for mouthpieces for use with smoking products or HNB products.

The present invention is generally related to a high capacity, high efficiency nonwoven filtration media comprising a gradient pore structure. In particular, the filtration media can comprise thermoplastic synthetic microfibers, fibrillated fibers, staple fibers, and a binder. Furthermore, the filtration media may be produced without the use of glass fibers or microglass fibers. Consequently, the filtration media of the present invention does not cause the same issues as conventional filtration media that comprises glass fibers and/or microglass fibers. Moreover, the filtration media can be used to treat fuel, lubrication fluids, hydraulic fluids, and various other industrial gases.

A nonwoven fabric manufacturing facility includes a fiber assembly manufacturing step and a heating and drawing step. In the fiber assembly manufacturing step, fibers formed using an electrospinning method are collected to form a fiber assembly. In the heating and drawing step, the fiber assembly is drawn to form nonwoven fabric in a state where the fiber assembly is heated to a melting point of the fibers. In the formed nonwoven fabric, an average pore diameter is 15 μm or more, a relative standard deviation of a pore diameter distribution is 0.1 or less, and an average fiber diameter of the fibers is 3 μm or less.

An object of the present invention is to provide cellulose acetate that has excellent compatibility with a resin, can reinforce a resin, and has excellent thermal stability. An embodiment of the present invention is cellulose acetate having a cellulose triacetate I crystal structure, wherein a temperature at which a weight loss relative to weight at 100° C. reaches 5% is 200° C. or higher when the cellulose acetate is heated at a heating rate of 10° C./min under a nitrogen atmosphere.