This paper introduces the application technology of ultrasonic plastic welding and several welding methods of plastic, and introduces the energy guide interface and fixture design to get the best welding quality. Key words: ultrasonic plastic welding, application technology, fixture design ultrasonic plastic welding equipment is one of the main ultrasonic equipment introduced by Shanghai bineng ultrasonic Co., Ltd. in order to make readers understand the application technology and equipment of ultrasonic plastic welding more comprehensively, this paper introduces the application technology and equipment of ultrasonic plastic material welding.

The high frequency vibration energy of ultrasonic is transmitted to the plastic parts (plastic parts of injection molding) which are welded through welding joints. The vibration energy is generated by impact friction between the plastic parts surface, and the temperature of the joint on the second surface of plastic parts increases, resulting in high heat, which makes the plastic at the joint melt and bond rapidly. When ultrasonic stops, plastic parts are still set under a fixed pressure for a short time, so that the finished products are strong and beautiful. The whole welding process is completed in a flash. Because ultrasonic welding is the melting of plastic parts and welding together, it is unnecessary to solder flux, adhesive or other auxiliary products, and the welding is firm, fast and beautiful. The welding of mass production plastic parts not only greatly improves the productivity, reduces the cost, but also improves the quality. Ultrasonic plastic welding is widely used for all kinds of thermoplastic plastics, so it can be used in electronic industry, automobile industry, electrical products, toys, packaging industry and textile industry.

Because of the outstanding advantages of ultrasonic plastic welding, such as short welding time; No surface damage, no appearance abnormality; There is no melting on the fusion surface; No heating is allowed in areas outside the welding part; The workplace has no peculiar smell, which makes it adapt to the mass production and automatic control of products, and has a broad development prospect in modern industry. When ultrasonic wave acts on plastic parts, friction between contact surface and molecule causes temperature rise dramatically. When the temperature is high enough to melt the plastic, a "plastic flow" of the material is generated between the two parts. When the vibration stops, the material will solidify under pressure and form a uniform welding. Because the melting material is solidified by pressure after ultrasonic vibration stops, the flow of the material will affect the quality and precision of welding. The proper welding joint can guide and control the flow of molten materials.