A study of polyvinylchloride-coated woven polyester fabric welding potential was conducted using continuous ultrasonic welding machines. The effect of cooling air, anvil wheel status, anvil wheel width, material surface contact, and welding gap on seam strength was studied. Three main welding parameters with different levels were selected based on 5 and 10 mm welding widths using old and new anvil wheels with and without cooling air. A lapped type of seam was applied under full factorial design. A microstructure was captured to examine the formation of welding joints, and seam tensile properties were determined. Comparative analysis of comparable welding parameters was analyzed for a gap against pressure and amplitude against power. The actual weld phenomenon was also analyzed based on the recorded machine parameters. The results showed that auxiliary parameters had a significant effect on seam strength. A microscopic image of a welded seam indicated that cooling air reduced the number and size of holes produced. Weld seam with controlled pressure or power provided higher seam strength than that of the controlled gap or amplitude. The actual phenomenon of welding parameters was important to evaluate weld seam quality, whereby the obtained results indicated good quality at lower power and pressure.