What is Ultra-Audio Frequency/Medium Frequency Heating?

Ultra-audio frequency heating utilizes the principle of electromagnetic induction. High-frequency current passes through an induction coil, generating a high-frequency alternating magnetic field that acts on metallic materials. This results in the induction of an electromotive force within the metallic materials, forming an alternating induction current, known as an eddy current, inside them. The thermal effect of the induced eddy current is utilized for heating, causing the plastic lining inside the tube to melt due to the heat. The pressure inside the tube then causes the melted plastic to adhere to the inner wall. By controlling the heating temperature and cooling effect, the production process requirements are achieved.