The principle of ultrasonic welding of mask machine
1. Overview of Ultrasonic Principle
The principle of multi-layer fusion of non-woven chemical fiber fabrics is mainly to use high-frequency friction between contact surfaces to rapidly generate heat between molecules. Under a certain pressure, it can weld multi-woven fabrics or fabrics or PVC films. . Frequently used in non-woven fabric welding processing frequency are 20KHz and 15KHz. Ultrasonic energy penetrates the material to fuse them together. Usually, tooth-like, net-like, and strip-like patterns are made on the welding head to form a pattern on the surface of the fused product. At the same time let the layers of fabric fuse together. Both disposable flat masks and N95 masks are manufactured in this way, and the mask ear straps are also spot welded by ultrasonic.
2. System combination
Ultrasonic welding systems are usually used in automatic equipment, coupled with automatic devices to complete continuous welding or reciprocating welding. Ultrasonic welding system usually includes: ultrasonic generator, ultrasonic transducer, ultrasonic welding mold (welding head) and related accessories, such as the flange plate for fixed support of the transducer, connecting cable, etc.
Ultrasonic generator is also called ultrasonic power supply and ultrasonic electric box. It is an electronic circuit device that can provide high-frequency current. With the addition of ultrasonic transducer, it can produce ultrasonic vibration energy. The principle of the ultrasonic transducer is to use the piezoelectric ceramic inverse effect, add a suitable high-frequency current to the transducer, and the same frequency mechanical vibration can occur. The ultrasonic generator, ultrasonic transducer, and ultrasonic welding head constitute a complete set of ultrasonic vibration device. The three components of the ultrasonic vibration device must reach resonance before they can work normally. Improper installation, connection, resonance frequency and adjustment will cause the system to be abnormal, and in severe cases, it will also damage the system.