Tensile Properties of Hollow Yarn by Friction Spinning

마찰방적 중공사의 인장성질

Hollow yarn was produced in an experimental friction spinning apparatus by inserting hot-water soluble PVA filament in the center of the cotton yarn. A 61/18 denier (6.8 tex) PVA filaments were inserted in the core and cotton fibers were wrapped in the sheath. As the yarn in the filament core and cotton sheath had high tensile strength, good breaking elongation, and high work of rupture, higher processing efficiency could be achieved in those processes such as weaving, knitting, etc. After the production of this yarn, the hot-water soluble PVA filament in the core of the yarn was removed in boiling water with a good extraction efficiency of more than 95%. The tensile strength of the hollow yarn (after the extraction of PVA) did not change with the remobal of the PVA. However, the breaking elongation fo the hollow yarn with the higher filament proportion was larger than that of the cotton friction spun yarn. Work of rupture in the hollow yarn after boiling showed mostly the same level and increased a little by increasing the PVA proportion so that the work of the rupture the yarn with a larger hollow center sustained a slightly increased level compared with the yarn with a smaller hollow center. The twist density (number of twists per meter) inserted into the core spun yarn showed the highest level at 10% PVA proportion and it decreased as the PVA proportion was increased.