| Ultrasonic welding is one of the most efficient methods of joining thermoplastics. This research investigated the effect of process parameters (welding time, holding time, welding pressure, and down speed setting) on the tensile strength of the ultrasonic welded parts. Amorphous ABS and PS, and crystalline HDPE and PP resins were used for this research. Experimental results showed that increasing the welding time increased the welded strength in all of the materials. Increasing welding pressure increased strength in all samples except HDPE. Increasing welding pressure caused HDPE welds to have lower strengths. The other parameters had little or no effect on the strength.;For all the polymers, increasing the welding time improved strength for welding times up to 0.4 sec. In PP, PS and ABS, increasing the weld pressure up to 12 psi increased the welded strength. Above 12 psi, ABS sample strength decreased. HDPE welded strength decreased when pressure was varied from 8 to 18 psi. |
