Vibration welding of thermoplastics. Part III: Strength of polycarbonate butt welds

Abstract

Abstract In vibration welding of thermoplastics, frictional work done by vibrating two parts under pressure, along their common interface, is used to generate heat to effect a weld. The main process parameters are the weld frequency, the amplitude of the vibratory motion, the weld pressure, and the weld time or weld penetration; The effects of these parameters on weld quality were systematically studied by first butt‐welding polycarbonate specimens under controlled conditions over a wide range of process parameters, and by then determining the strengths and ductilities of these welds by tensile tests, A significant result is the apparent existence of a weld‐penetration threshold above which high weld strengths are attained, but below which the strength drops off. Under the right conditions, the strengths of polycarbonate butt welds are shown to equal the strength of the virgin polymer.