Mechanical performance and microstructural behavior of ultrasonically welded PVC-coated polyester fabric seams at...

Area of Science:

• Materials Science
• Mechanical Engineering
• Textile Engineering

Background:

• Ultrasonic welding is crucial for PVC-coated polyester fabrics in demanding membrane structures.
• Seam reliability is paramount, particularly in cold-service conditions.

Purpose of the Study:

• To systematically investigate how welding pressure, coating thickness, seam margin, and temperature affect the mechanical performance of ultrasonically welded seams.
• To understand the failure mechanisms and optimize welding parameters for PVC-coated textile structures.

Main Methods:

• Full-factorial experimental design to test various welding parameters.
• Load-extension analysis to evaluate seam strength, extension at failure, work of rupture, and seam efficiency.
• Fractographic, FTIR, and EDS analyses to examine failure modes and material changes.

Main Results:

• Increased welding pressure and coating thickness significantly enhanced seam strength and energy absorption.
• Higher seam margin at 2.5 bar pressure led to a substantial increase in seam strength.
• Cold temperatures (-20°C) resulted in higher strength but reduced ductility, indicating a stiffer response.

Conclusions:

• Ultrasonic welding parameters, particularly pressure and thickness, are critical for achieving high-performance seams in PVC-coated fabrics.
• Optimized parameters ensure durable seam performance across a range of temperatures, from ambient to subzero.
• Predictive models were developed for reliable strength forecasting under varied conditions.