In the air gap, there are several p

In the air gap, there are several processes going on: the reduction in temperature of the filament, the mass transfer of water across its surface, the accel­ eration of the material and reduction in its diameter, the orientation of the polymer chains, and the pos­ sible crystallization of the cellulose or the cellulose solution. In this work, we looked at the effect of the air-gap conditions on the fiber formation. The air­ gap length was studied and, in particular, the effect of shortening it to shorter than the draw length (i.e., the distance in which the filament is fully drawn2). We imposed different air conditions (temperature and relative humidity) on the fiber from cold and dry to warm and humid to determine if this causes any difference to the several processes involved. The water content in the cellulose solution has also been varied to give a different rate of mass transfer into and out of the filament.