“…As was observed by SEM, the fiber system with 1 wt% of PTT showed two different trends of fibrillation. Here, it may be deduced that temperature plays a crucial role in fibrillation threshold which can be seen that fibrillation shifts to 1 wt% of PTT in the fiber spun at 240 °C, which is not the case in previous works conducted at temperature below the T m of dispersed phase 30,39,45,47. According to the reported works, since viscosity ratio and processing conditions are under control of disperse‐phase ratio and temperature respectively, the fibrillation of each polymer blend system is also dependent, whose dependent fibrillation appears by forming fibrils with different lengths 2,14,18,28,30,31,36,38,47,51…”