Design of a radial ultrasonic horn for plastic welding using finite element analysis

Abstract

In this paper, a radial ultrasonic horn is designed by finite element analysis. Three different modes are obtained corresponding to specific natural frequencies. The distribution of amplitude and stresses of resonant mode shape are investigated. The 7075 aluminum grade is utilized for fabricating the radial ultrasonic horn. The ultrasonic sewing machine using the radial horn is established. The measured frequencies of the simulated and machined results are compared. Two kinds of polyvinyl chloride (PVC) tarpaulin fabrics with densities of 220 g sqm−1 and 320 g sqm−1 are welded by the radial ultrasonic welding system. Two patterns of the rollers are utilized for testing the welding ability of the machine. The ultrasonic power, air pressure, and the velocity of the roller are set at 1500 W, 3 kg cm−2, and 6 m min−1, respectively. Good welding joints are achieved. The tensile strengths of welding joints of two tarpaulin sheets are measured as 144.9 g mm−1 and 134.6 g mm−1, respectively.