Fastener stringer and method for manufacturing fastener stringer

A concealed slide fastener including a pair of fastener stringers, each of the fastener stringers including a knitted fastener tape and a plurality of fastener elements attached to an element attaching portion of the knitted fastener tape with machine sewing yarns, the knitted fastener tape including a tape main body portion and a doubled-tape portion along a longitudinal edge of the knitted fastener tape forming, in cross-section, a U-shape with a first tape portion of the U-shape extending from a longitudinal portion of the tape main body portion, the doubled-tape portion including the element attaching portion, wherein

• at least a chain stitch yarn is included in each of a plurality of wales forming the tape main body portion, and
• a plurality of wales forming the doubled-tape portion include at least one wide wale having a second wale width that is greater than a first wale width of the plurality of wales forming the tape main body portion, wherein
• the tape main body portion and the doubled-tape portion include tricot stitch yarns and single satin stitch yarns,
• the tricot stitch yarns include a first tricot stitch yarn and a second tricot stitch yarn having higher strength or larger fineness than the first tricot stitch yarn and having a needle loop formed in the doubled-tape portion, and
• the single satin stitch yarns include a first single satin stitch yarn and a second single satin stitch yarn having higher strength or larger fineness than the first single satin stitch yarn and having a needle loop formed in the doubled-tape portion.

A method for manufacturing a concealed slide fastener including a pair of fastener stringers, each of the fastener stringers including a knitted fastener tape and a plurality of fastener elements attached to an element attaching portion of the knitted fastener tape with machine sewing yarns, the knitted fastener tape including a tape main body portion and a doubled-tape portion that is formed by extending in a width direction from the tape main body portion and being folded back, the doubled-tape portion including the element attaching portion, wherein the method comprises:

• knitting the knitted fastener tape in which at least a chain stitch yarn is included in each of a plurality of wales forming the tape main body portion and a water-soluble chain stitch yarn is included in at least one of wales forming the doubled-tape portion;
• sewing the plurality of fastener elements to the element attaching portion of the knitted fastener tape by a sewing processing using a sewing machine;
• and
• dissolving and removing the water-soluble chain stitch yarn of the knitted fastener tape to which the plurality of fastener elements are sewn to form, in the doubled-tape portion, at least one wide wale having a second wale width that is greater than a first wale width of the plurality of wales forming the tape main body portion.