| 摘要 |
PROBLEM TO BE SOLVED: To provide a method for obtaining a coil which is made from a synthetic resin and is made to have an optional pitch or optional initial tension although a fixed shaping shaft is used.SOLUTION: A method for producing the coil, which is made from the synthetic resin and has the pitch wider than that of a metallic screw to be used as the shaping shaft, comprises: a step (A) of applying a Z twist to a multifilament yarn 1 obtained by bundling core-sheath conjugate fibers each having a low melting point polymer as a sheath component and a high melting point polymer as a core component; a step (B) of winding the Z twist-applied multifilament yarn 1 spirally along the pitch of the Z-twisted metallic screw while keeping a Z-twisted state of the multifilament yarn 1; a step (C) of heat-treating the multifilament yarn 1 wound around the metallic screw so that only the sheath component is softened or melted, the adjacent core-sheath conjugate fibers are welded to each other and a synthetic resin-made coil line is obtained from the multifilament yarn 1; and a step (D) of removing the synthetic resin-made coil line from the metallic screw to obtain the synthetic resin-made coil. |
