the moving parts of the rotary-jet equipment (rotor, spinning
head) and polymer fiber collector. The rotational speed, air
flow and temperature, polymer dosage, and exhaust blowers
are externally controlled.
Different spinning heads with various geometries were
tested to obtain a preliminary evaluation of fibers deposition
(Figure 2).
Discontinuous depositions were carried out by using a
cylindrical spin head provided with individual spinnerets
having limited storage capacities for polymer solutions
(Figure 2(c)). This procedure was applied for obtaining
mixed fibers from two polymer solutions made in different
solvents, in particular gelatin (30 % w/v) and PU (20% w/v).
Two spinnerets were used to obtain a 1:1 ratio between
mixed polymer fibers (GPU1), and three spinnerets for G/
PU ratios of 1:2 (GPU2) and 2:1 (GPU3). In all other cases,
a continuous deposition was achieved by supplying the
polymer solutions, with an appropriate flow controlled by a
peristaltic pump, from an external reservoir to the center of
the spinning head through a central pipe (Figures 2(a), (b)
and (d)). Besides the pure polymer solutions (PVC, PU,
G30%, and G40%), the blend of G30% with chitosan (4%