Abstract
Polyester Shin-gosen fibers were heat-set and subjected to supercritical CO2 fluid treatment (SFT, 125 °C, 25 MPa, 60 min) or pressurized water treatment (PWT, 130 °C, 60 min), where the shrink behavior and the mechanism were compared. As for PWT, heat-set temperature over than 160 °C was enough for the suppression of shrinkage lower than 2%. On the contrary, as for SFT, the shrinkage could not be suppressed at the same level even in the case for the fibers heat-set at 200 °C. The large shrinkage seems to be brought about by the migration of oligomer through SFT. The oligomer migration lowered the tensile modulus, and gained the elongation of the treated fibers. However, the tensile strength of the fiber was hardly affected by SFT.
