Relationship between horn pressure and welding time in ultrasonic welding of plastic pipes using torsional vibration

application of ultrasonic welding to plastics has become common. Recently, an ultrasonic welding method for long plastic pipes using torsional vibrations was developed. Optimal welding conditions for this new method have not yet been clarified. This paper reports the results of an investigation made in order to clarify the conditions, focusing on the welding time and both horn pressure, static force that horns pinch pipe, and static pressure which is added to welding surface, Experiments were performed on the welding of acrylic resin and ABS resin pipes. It was found that welding time decreases exponentially with increasing horn pressure and that increasing the static pressure reduces the welding time. It was also found there is an optimum range of horn pressures.