Ultrasonic Welding Abstract

Plastics being welded ultrasonically is widely used everywhere under the applications of industries , commercial and medical. The Purpose of the project is to analyse the joint strength of different combinations of dissimilar materials being welded ultrasonically and also to reduce the weight factor and economic factors. Three input parameters namely material , weld time , weld pressure and one output parameter namely joint strength is chosen. The input parameters are set in Ultrasonic welding machine and the output parameter is determined by Universal testing machine. The joint strength is determined by means of Universal testing machine. Design of experiments is applied to conduct the experiments based on the input and output parameter. Plastics

INTRODUCTION

Ultrasonic welding is an industrial technique whereby high-frequency ultrasonic acoustic vibrations are locally applied to workpieces being held together under pressure to create a solid-state weld. It is commonly used for plastics, and especially for joining dissimilar materials. In ultrasonic welding, there are no connective bolts, nails, soldering materials, or adhesives necessary to bind the materials together. For joining complex injection molded thermoplastic parts, ultrasonic welding equipment can be easily customized to fit the exact specifications of the parts being welded. The parts are sandwiched between a fixed shaped nest (anvil) and a sonotrode (horn) connected to a transducer, and a 20 kHz low-amplitude acoustic vibration is emitted. When welding plastics, the interface of the two parts is specially designed to concentrate the melting process The ultrasonic energy melts the point contact between the parts, creating a joint. Ultrasonics can also be used to weld metals, but are typically limited to small welds of thin, malleable metals, e.g. aluminum, copper, nickel. Ultrasonic welding of thermoplastics causes local melting of the plastic due to absorption of vibrational energy along the joint to be welded. In metals, welding occurs due to high-pressure dispersion of surface oxides and local motion of the materials.. Ultrasonic welding can be used for both hard and soft plastics, such as semicrystalline plastics, and metals. Ultrasonic welding machines

LITERATURE REVIEW

Umang Parmar et al. [1], experimentally investigated the ultrasonic welding of thermoplastics is one of the joining methods which is based on application of high-frequency vibratory energy in that workpieces are held together under pressure without melting. This study involves the experimental data of joint strength of acrylonitrile butadiene styrene (ABS) material for ultrasonic welding on welding parameters (welding pressure, welding time and amplitude) and critical states of the welding parameters has been analysed by analysis of variance.

Mantra Prasad satpathy et al. [2], research work explored the joints of various dissimilar metals produced by ultrasonic spot welding and the weld strength, interface temperature ,weld area ,micro hardness were measured as well as the quality of the weld revealed for different weld times. Further increase in weld time, the interfacial temperature was far above than the recrystallization temperature, showing a substantial loss in joint