Abstract
To improve the wet tensile strength of calcium alginate gel fibers, the effects of stretching and the diameter of the extrusion nozzle on the wet tensile strength of calcium alginate gel fibers were evaluated. Five kinds of algal sodium alginates [low viscosity types (150-M and 150-G) and high viscosity types (350-M, 350-G, and I-5G)] were used as raw materials for calcium alginate gel fibers. Stretching and extrusion nozzle diameter had significant effects on the wet tensile strength of calcium alginate gel fibers. After stretching the original gel fiber length up to 1.4-fold, the wet tensile strength of gel fibers derived from high viscosity type alginates was increased by up to 1.97-fold～2.12fold of the wet tensile strength of each of the original gel fibers. Furthermore, by stretching the original gel fiber length by up to 1.8-fold, the wet tensile strength of each of the original gel fibers was increased by up to 2.35-fold～2.54-fold. The gel fiber strength was also increased by decreasing the extrusion nozzle diameter. From these results, the stretching treatment appears to be a useful process for improving the wet tensile strength of calcium alginate gel fibers.
