Lyocell is made by treating wood chips approximately the size of a coin in an amine oxide,
n-methylmorpholine oxide (NMMO), an organic solvent
that is much less harmful or irritating than others used in fiber production.
After the clear, viscous (thick, sticky) liquid is filtered, it is extruded
(spun) in a bath of dilute NMMO, where the fiber coagulates as reconstituted
cellulose. It is then washed and dried. Like cuprammoniurn, lyocell has a
smooth surface and a round cross section. Since virtually all the solvent can
be recovered and used again, the process is largely pollution free.
