Ultrasonic welding conditions
Ultrasonic welding conditions: As the conditions of ultrasonic welding, the most important thing is the length of time (vibration, welding time) and pressure applied to the welding energy. Of course, other conditions are also very important. Welding temperature The viscous flow temperature of the ultrasonic welding material. Otherwise the material will not melt. Related to the amplitude, the higher the amplitude, the higher the temperature rise.
The pressurizing force uses a cylindrical tool to pressurize the molded product. Generally, the compressed air pressure is 0.1-0.3MPa (pressure gauge), sometimes higher. However, if high pressure is used, the cylindrical vibration will be hindered. The welding time varies depending on the type of material and the shape of the product. The welding time of some molded products is only 0.2 seconds. Too long time will cause excessive welding and produce a large number of flashes and bubbles, which will lead to poor air tightness, which must be paid attention to. Cooling (holding) time. For crystalline plastics, if the temperature is below the melting point, the connecting part will be solidified, and the pressurizing time is usually maintained between 0.1 and 0.2 seconds.
Ultrasonic welding machine requirements: the welding head is divided into three parts from bottom to top: welding head, amplifier and transducer (ultrasonic transducer). The three are enlarged according to a certain ratio. If the amplitude of the transducer is 6MM, the amplifier can amplify three times to 18MM, and the amplitude to the welding head can be increased to 36MM. Of course, as the amplitude increases, the life of the welding head will decrease. Different materials to be welded require different amplitudes. There are generally three types of welding head materials: Titanium: expensive, with the best performance, good toughness, and difficult to process. The friction loss is small, and the amplitude can reach 60MM; aluminum alloy: cheap, fast wear, the amplitude cannot exceed 30MM, easy to process; steel: very hard, the most unsuitable for welding head, the amplitude cannot exceed 25MM, suitable for cutting, need to increase the blower pipe , Easy to cool. Therefore, the application range of ultrasonic car welding is: car door panels, car door panel sound insulation felt, automotive non-woven fabric interior parts spot welding, automotive dashboards, automotive dashboards, automotive plastic parts riveting, automotive bumpers, automotive tire covers, automotive roofs , Car trunk non-woven fabric, car seat cushion non-woven fabric, car engine cover, car tail light, car lampshade, car bearing cage, car glove box, car filter, car plastic valve, car air commutator, Automobile airflow detectors, etc. For the welding of automotive plastic parts, non-standard ultrasonic welding equipment is mostly used, multi-head multi-station design, with PCL program control and LCD screen operation, large-scale automobile welding of complex workpieces, including welding surfaces in different directions, and multiple positions need to be welded at the same time Embarrassed.
