| 摘要 |
PURPOSE:To provide a string for a racket for which products of uniform quality can be manufactured in a short time at a low cost substantially without applying heat in the last process, of which color can be changed when necessary, to which odor is added, and which is provided with a large variety in surface hardness, etc. CONSTITUTION:Using a lateral twister, for mono- or multi-filament of nylon 6 or the likes as a core yarn 5, a thermoplastic resin binding agent dissolved in solvent is applied in a first resin tank 7, and mono- or multi-filament of nylon 66 or the like is twisted as a sheath yarn 6 around it. The twisted core yarn 5 with the sheath yarn 6 is dried in a drying device 8, so the core yarn 5 is integrated with the sheath yarn 6. Next, ultraviolet ray-setting resin is applied in a second resin tank 9, ultraviolet rays are radiated by an ultraviolet ray radiation device 10, and the yarn is taken up by a bobbin 11. At this time, the bobbin 11 is rotated in the arrow direction, for example, to twist a string in taking it up. |
