Air-Drag Coefficient of Polyester Textured Yarns

The correspondence to consumer needs and the development of high value added products are required for the textile manufactures. The textile manufacture is obliged to shift to a large variety and small quantity of production. The improvement in efficiency of warp preparation and a quick determination of weaving conditions (air pressure and injection timing) is important to the air jet loom (AJL). In order to obtain basic data for determining quickly the weaving conditions in AJL of the profile reed with sub-nozzles, the air-drag coefficient of eight kinds of polyester textured multi-filament yarn was measured, and the factors which affect the air-drag coefficient of yarn were investigated. The following conclusions were obtained as a result. (1) The air-drag of polyester textured yarns which are 16.5 tex and 33.9 tex with 96 filaments became the largest. (2) Measuring the diameter of polyester textured yarn used in the experiment, the diameter changes with the static loads and approaches to about 1.8 times as long as the equivalent diameter calculated from yarn count. (3) The air-drag coefficient of polyester textured yarns used in the experiment is explained as a function of a Reynolds number.