The Influence of Fillers and Dyes on the Quality of Weld Joints at Ultrasonic Welding of Plastics

Abstract

In this work, the impact of dyes and fillers on the process of heat generation during ultrasonic welding of plastics was studied, which made it possible to influence the weldability and quality of products. Experiments to weld samples of plastics with various concentrations of dyes and fillers were carried out. Based on the experimental data, it was established that the main parameters of the welding process and the properties of the polymer influenced weldability and performance indicators of the weld joint. The nature and the concentration of the dyes and fillers injected into the polymer to obtain certain characteristics and colors had an impact as well. Optimal concentrations that provided the best weldability, strength and quality of the weld products were obtained for fat-soluble dyes and organic pigments (0.1–1.5 g/kg) as well as disperse fillers and inorganic pigments (5–12 g/kg). Types of dyes and fillers and their optimal concentrations for fat-soluble dyes, organic pigments and disperse fillers were determined. Parameters of the process of ultrasonic welding of dyed and filled plastics were defined. It was established that welded products with the recommended optimal concentration and types of dyes and fillers showed the best weldability, increased strength and performance, and could be used longer under various climatic conditions.