Typically, XLA core yarn for yarn dyed fabric is same as that for weave fabric, for which pre-treatment including steaming, boiling, bleaching, dyeing (optional) and inverted tube processing is necessary. Similar to pre-treatment for normal spandex core yarn, the process for XLA should be focused on two key points:
　　1、During entire process of pre-treatment, the highest temperature shall be controlled under 85℃, including steaming process;
　　2. Because internal stress of XLA is smaller than that of ordinary spandex, the yarn tube for pre-treatment of XLA could be weight 1.5 times of that for spandex to improve work efficiency of equipments.