The principle of ultrasonic plastic welding: 20KHZ, (or 15KHZ) high-voltage, high-frequency signal is generated by the generator, and the signal is converted into high-frequency mechanical vibration through the energy conversion system, which is applied to the plastic workpiece through the working surface and internal molecules When the temperature reaches the melting point of the workpiece itself, the welding port of the workpiece melts quickly, and then fills the gap between the ports. When the vibration stops, the workpiece is cooled under a certain pressure at the same time. After finalizing, perfect welding can be achieved.

The actual operation of the ultrasonic welding machine is not perfect.

It is generally believed that during ultrasonic operation, the product and the mold surface can get the welding effect of the ultrasonic welding machine as long as the contact is accurate. In fact, this is only a superficial view. Since the ultrasonic wave is frictional vibration, it will produce the phenomenon of sound wave transmission.

If we only observe the degree of stability of the hardware (mold) and ignore the integrated ultrasonic operation method, it will inevitably lead to the consequences of ruining everything or misjudgment. Therefore, we must first emphasize that the operation method of ultrasonic welding is to conduct sound waves. The vibration and friction are turned into heat energy for welding, and the degree of stability of the ultrasonic mold, the height of the product section, the thickness, depth, and the difference of the material must not be 100% able to withstand the same pressure.

On the other hand, the energy output by the upper mold has an error value for each point, and the energy emitted by the entire surface is not the same. On the whole, there is bound to be a difference in the degree of welding of the product welding line. Therefore, it must be corrected, relying on the horizontal screw of the ultrasonic welding machine itself, or sticking a thinner tape or aluminum foil to overcome it.

The melting point of each plastic material is different. For example, the melting point of ABS plastic material is about 115°C, Nylon is about 175°C, PC is above 145°C, and PE is about 85°C. For example: the difference in melting point between ABS and PE Too big, ultrasonic welding is bound to be difficult. There is also a gap between the two materials of ABS and PC, but the gap is not as large as the previous item. Therefore, it can be welded, but under the same ultrasonic power and energy expansion, different plastic materials cannot be compared. The welding effect of the same material is good.

When customers purchase ultrasonic welding machines, it is usually difficult to predict the specifications of future product development, so they will encounter situations where larger product objects exceed the ultrasonic standard welding. At this time, under the budget of not increasing the cost, only the existing equipment can be used for production. The usual method is to weld several times, increase the ultrasonic output power (increase section) or increase the welding time and pressure. However, this also produces the phenomenon of unstable quality, because the voltage and air pressure directly affect the stability of the ultrasonic output power.