1. The materials of two weldments shall be fusible

Some Weldments of different materials cannot be welded. Theoretically, the same material can be welded. However, when the melting point of the weldment is higher than 350℃, ultrasonic welding is not suitable. This is because ultrasonic welding uses the instantaneous energy to melt the molecules. This welding instant shall not exceed 3 seconds. If it cannot be welded well within 3 seconds, it indicates that it is not suitable. Therefore, attention shall be paid to the selection of weldments.

2. The thermal resistance of the weldment shall be higher than its melting point

The ultrasonic wave propagates in the solid through the weldment, and it propagates in the air between the two weldments. The acoustic resistance of the ultrasonic wave propagating in the air is greater than that in the solid. The greater the acoustic resistance, the higher the heat generated. Therefore, the temperature of the part in contact with the two weldments is higher, reaching the melting point first. When propagating inside the weldment, the acoustic resistance is small, the temperature is relatively low, and the melting point will not be reached.

3. Connection area and distance required

The welding contact area between two weldments shall meet the welding requirements and shall not be too large or too small. Too much contact will lead to scattered welding energy, insufficient welding strength, or even unable to weld together at all. The contact is too small to weld firmly, and it is easy to break. The longer the distance, the more energy will be lost. Therefore, the welding distance should be controlled.

4. The importance of ultrasonic mould

The manufacture of ultrasonic welding head mold can only be done through a set of strict procedures. This is not something that ordinary small workshops can complete. Therefore, do not buy Ultrasonic molds from small manufacturers, which will make you unable to weld well.

5. Keep the output power of the machine constant

To ensure that the output power of the ultrasonic plastic welding machine is constant when it is working, do not go from high to low, which will have a bad impact on the weldment.