Abstract: The effects of the pressure and speed of pattern roller, ultrasonic power on the seam mechanical properties of polyester fabric welded by ultrasonic sewing machine were studied by constant-rate stretching of the seams welded under different conditions. The results showed that better mechanical properties were achieved under higher pressure and lower speed of the pattern roller, and higher ultrasonic power. The seam strength, extension and work at break are positively correlated with the ultrasonic welding factor (pressure*power/speed) put forward in this paper, which can be used to characterize the seam mechanical properties of fabric welded, and to simplify the adjusting procedure of ultrasonic sewing machine.

Key words: ultrasonic sewing, polyester fabric, pressure, seed, power, mechanical property