Lyocell

Unlike rayon made by the more common viscose processes, Lyocell production does not use carbon disulfide,[2][3] which is toxic to workers and the environment.

[3][6] The U.S. Federal Trade Commission defines Lyocell as "a fiber composed of cellulose precipitated from an organic solution in which no substitution of the hydroxy groups takes place, and no chemical intermediates are formed".

[12] The operating name for the fiber inside the Enka organization was "Newcell", and the development was carried through a pilot plant scale before the work was stopped.

The basic process of dissolving cellulose in NMMO was first described in a 1981 patent by Mcorsley for Akzona Incorporated[12][14] (the holding company of Akzo).

Lyocell may be blended with a variety of other fibers such as silk, cotton, rayon, polyester, linen, nylon, and wool.

[23] Lyocell shares many properties with other fibers such as cotton, linen, silk, ramie, hemp, and viscose rayon (to which it is very closely related chemically).

[25] Compared to cotton, consumers often say Lyocell fibers feel softer and "airier," due to their better ability to wick moisture.

Hardwood logs (such as oak and birch[better source needed][27]) are chipped into squares about the size of postage stamps.

The pulp is bleached to remove the remaining traces of lignin, dried into a continuous sheet and rolled onto spools.

At the Lyocell mill, rolls of pulp are broken into one-inch squares and dissolved in N-methylmorpholine N-oxide (NMMO[2]), giving a solution called "dope".

The spinneret is pierced with small holes rather like a shower head; when the solution is forced through it, continuous strands of filament come out.

The strands pass to a finishing area, where a lubricant, which may be a soap or silicone or other agents, depending on the future use of the fiber, is applied.

At this stage, the dried, finished fibers are in a form called tow, a large, untwisted bundle of continuous lengths of filament.

The crimped fiber is then carded by mechanical carders, which perform a combing action to separate and order the strands.

In chemical reaction methods, antibacterial additives are crosslinked into the Lyocell fibers and therefore giving antimicrobial properties.

In post-treatment methods, antibacterial additives are being deposited on Lyocell fiber surfaces through physical coating, padding, or impregnation processes.