Several problems needing attention in ultrasonic welding

1. Weldability of two workpieces during welding

Some of the different materials can be fused better, some are basically miscible, and some are non miscible. The same material can be welded in principle, but when the melting point of the workpiece to be welded is greater than 350 ℃, it is not suitable for ultrasonic welding. Because ultrasonic wave can melt the workpiece molecules instantly, it is better to do so within 3 seconds. If the welding process cannot be well welded after 3 seconds, other welding processes shall be selected. Generally speaking, ABS material is the easiest to weld, and nylon or PP material is generally weldable.

2. Welding die structure shall be strictly inspected

There is a set of strict inspection procedures for the incoming materials of regular ultrasonic die production, and the processing dimensions are processed after computer software simulation and verification, so the quality is guaranteed. These processes can not be achieved in general workshops. If the mold is made without reasonable design, when welding small workpieces, the reaction problem is not obvious. When the power is high, there will be various drawbacks, which will directly damage the power components in serious cases. Therefore, do not be greedy for cheap when buying ultrasonic welding molds. Only high-quality molds can ensure the quality of processed products.

3. The thermal resistance shall reach the melting point of the workpiece during welding

After the ultrasonic transducer converts the electrical energy into mechanical vibration, it conducts through the material molecules of the workpiece. The acoustic resistance of the ultrasonic wave in the solid is far less than that in the air. When the acoustic wave passes through the seam of the workpiece, the acoustic resistance in the seam is large, and the heat energy generated is quite large. The temperature reaches the melting point of the workpiece. With a certain pressure, the seam is welded. The other parts of the workpiece will not be welded due to low thermal resistance and low temperature.

4. There are certain requirements for welding area

When the ultrasonic instantaneous energy is generated, the larger the welding area, the greater the energy dispersion, the worse the welding effect, and it may be impossible to weld. In addition, the ultrasonic wave is transmitted longitudinally, and the energy loss is proportional to the distance. The distance welding should be controlled within 6cm. The welding line should be controlled between 30 and 80 wires, and the arm thickness of the workpiece should not be less than 2mm, otherwise it cannot be welded well, especially for products requiring air tightness.