Ply Yarn, Yarn Plying

Ply, plied, or folded yarn, is made by twisting two or more single yarns together, usually by combining singles twisted in one direction with a ply twist in the opposite direction. Ply yarns are composed of two or more single yarns twisted together. Two-ply yarn, for example, is composed of two single strands; three-ply yarn is composed of three single strands. All yarns are originally spun as single yarns, but for certain end uses, single yarns may be twisted together to produce a ply yarn. Most common are two-ply yarns, formed by twisting two single yarns together. The plying twist is in the opposite direction of the singles twist. That means most ply yarns will contain an “S” twist. Ply yarns are used where extra strength and evenness are required. When a yarn is plied, the ply can be indicated in the yarn number. A single yarn and a plied yarn may have the same effective yarn count, but the plied yarn would be made up of two singles yarns which are half the size of the final, total yarn count. For the English Cotton Count yarn numbering system, a singles yarn would be written with the count/1 while a doubles or plied yarn would be written with the size/2. For two yarns both equaling an Ne 24 yarn number, in which one yarn was a singles or un-plied and the second yarn was a doubles or 2-ply, the singles yarn would be written Ne 24/1 and the doubles yarn would be written Ne 48/2. These would be read out loud as 24 singles or 48 doubles. Remember that English Cotton Count is an indirect yarn numbering system, and so an Ne 48/1 yarn would be half the size of an Ne 24/1 yarn. Two Ne 48/1 yarns plied together would have an equivalent count to a Ne 24/1 yarn. 

Single yarn is formed by twisting fibers or filaments in one direction. Ply yarn is made by combining singles twisted in one direction with a ply twist in the opposite direction. Twine, cord, or rope can be made with a cable twist, each twist in the opposite direction of the preceding twist (S/Z/S or Z/S/Z), or with a hawser twist, the single yarns and the first ply twist in one direction and the second ply twist in the opposite direction (S/S/Z or Z/Z/S). The number of turns per unit of length in a yarn affects the appearance and durability of fabric made from that yarn. Yarns used for soft-surfaced fabrics have less twist than those used for smooth-surfaced fabrics. Yarns made into crepe fabrics have maximum twist.