Abstract
Majority of finishing process requires the thermal curing which affects physical properties of fabrics. Therefore, effects of thermal treatment on physical properties of cellulosic fibers, viscose and polynosic rayons and cotton, were investigated under various thermal conditions in order to obtain some aids to establish the most adequate condition for finishing.
The results are summarized as follows :
Tensile strength, elongation and Young's modulus showed, especially in the case of viscose, some increase through thermal treatment depending upon heating conditions, which empirically proved an additional hydrogen bond formation in the amorphous region of the cellulosic fibers. It was disclosed that the highest improvement of tensile strength was given by heating at 180°C in every case.
On the other hand, polynosic showed a considerable reduction of tensile strength at 200t and higher, which is attributed to residual sulfur to be oxidized to sulfite followed by accelerating oxidation of fibers at high temperatures.
Single fibers were affected by heating for shorter time at lower temperature compared with in the case of fabrics.
Decrease in swelling volume as well as in accessibility of the fibers observed after the thermal treatments also evidenced an increase in hydrogen bonds newly formed by the thermal treatment, which might give an increase in tensile strength when it might overcome any degradation of fibers to be caused thermally and chemically.
