本實驗採用十字斷面聚酯加工絲與Greencell長纖維原絲作為鞘紗，並以Lycra彈性纖維作為芯紗，而兩種鞘紗分別為第一包繞之情況下在不同撚度及撚向進行實驗討論。實驗中撚度為TPM 100、500、900三種撚度，撚向為SZ、ZZ、ZS、SS四種撚向，以及兩種紗線使用不同包繞順序。實驗結果顯示：在撚度超過500時超過飽和撚度，三種撚度中，強伸度大小順序為TPM 500>100>900。在撚向相反時比起撚向相同時，擁有更好的紗線結構穩定性，其強伸度大小為撚向相反>撚向相同。
In the study, the elastic double covering yarn composed of sheath yarn that consist of cross-section polyester draw texturing yarn and Greencell® filament yarn and core yarn that consist of Lycra®. The effect of 1st covering yarn selection, twist direction in SZ, ZZ, ZS and SS and the nominal turns per meter (TPM) of 100, 500 and 900 were studied. From results, TPM of 500 was over maximum nominal turns per meter. The yarn breaking force and elongation was highest when the TPM was 500 and lowest when TPM was 900. Yarn structure was more stable and the yarn breaking force and elongation was increased if twist direction was opposite.
