The influence of wet/dry treatment on pore structure-the correlation of pore parameters, water retention and moisture regain values

Three types of regenerated cellulosic fibres, normal lyocell (CLY1), crosslinked lyocell (CLY2 and CLY3), and micromodal (μCMD) were treated with five two-stage cycles comprised of wetting in water at 40 °C for 6 h, and drying at 105 °C for 6 h. The resulting changes in fibre pore characteristics were then estimated with Inverse Size Exclusion Chromatography, water retention values (WRV), and moisture regain values (MRV). Reductions in fibre pore volumes after wet/dry treatments were observed to the extents of 20, 13, 18, and 0% in CLY1, CLY2, CLY3 and μCMD, respectively. Corresponding reductions were also observed in water retention and moisture regain after the treatments. WRVs decreased by 21, 28, 24 and 14%, and MRVs decreased by 48, 43, 34 and 40% in CLY1, CLY2, CLY3 and μCMD, respectively. anges observed in pore characteristics, WRVs and MRVs are attributed to changes that occur in the microstructures of fibres. It is proposed that structural rearrangements occur in fibres during repetitive wetting and drying that leads to decreased water sorption.