Technical requirements for welding of ultrasonic plastic welding machine

1. The heat transfer coefficient must be the melting point of the product workpiece

The ultrasonic transducer converts electromagnetic energy into mechanical equipment, and then transmits it according to the molecular structure of the chemical substance in the product workpiece. The sound resistance of solid ultrasonic frequency propagation is much lower than that in air. When the sound wave frequency is based on the joint of the product workpiece, the acoustic resistance in the gap is larger, resulting in a larger energy source. The temperature first reaches the melting point of the product workpiece, and a certain working pressure is added to dissolve the joint. The other parts of the product workpiece are not easy to dissolve due to the low heat transfer coefficient and low temperature.

2. The two products must be fusionable

Some of the different materials can be welded better, some are basic fusion, and some are not. The intermediate melting point of the same raw material is the same, and welding can be carried out according to the basic principle. But if the melting point of the welding workpiece exceeds 350°C, it is not suitable for ultrasonic welding. Since ultrasonic waves instantly melt the molecular structure of the product workpiece, and the resolution is based on less than 3 seconds, it is impossible to perform excellent welding, so other welding processes must be selected. Such as heating plate welding. Generally speaking, ABS materials are easy to weld, while polyester or PP materials are difficult to dissolve.

3. There are certain regulations on the total area of the joints

When the instantaneous kinetic energy is caused, the larger the total area of the joint, the more serious the kinetic energy dispersion, the worse the actual welding effect, or even the failure of welding. In addition, the ultrasonic wave propagates vertically, and the kinetic energy damage is positively related to the spacing. Long-distance welding should be controlled within 6 cm. The welding seam should be controlled in the middle of the 30-80 line, and the arm thickness of the product workpiece should not be less than 2mm, otherwise it cannot be welded well, especially the goods with good air tightness.

4. The power of ultrasonic plastic welding machine must be constant

The power of the ultrasonic plastic welding machine is the same as the diameter, thickness, material and processing technology of the piezoelectric ceramic chip. Once the ultrasonic transducer is shaped, it will be shaped for high power. Considering the magnitude of output kinetic energy is a complicated process. It is not that the larger the ultrasonic transducer, the more ultrasonic rectifiers used in the power circuit, the greater the output kinetic energy. It requires a very complex amplitude detector to accurately measure its amplitude.

5. Get rid of the wrong concept of ultrasonic welding models

It is necessary to consider the power, oscillation frequency, and amplitude range according to the raw materials of the product workpiece, the total area of the welding wire, whether there are electronic components in the product workpiece, and whether air tightness is required. Misunderstood that the greater the output power, the better. This is also a misunderstanding. If you don’t know much about ultrasound. The engineering project consults the reliable professional and technical personnel of the ultrasonic manufacturer. If there is a standard, it is to communicate with the manufacturer on the spot, and you don't have to blindly follow the trend and follow the fraud of some informal ultrasonic equipment salespersons.

6. Ultrasonic ultrasonic mold structure must be strictly tested

Reliable ultrasonic mold shell manufacturers have a set of strict inspection procedures and processes, and the production and processing specifications are all produced and processed after computer technology simulation verification. Quality is guaranteed. This kind of technological process cannot be guaranteed in general small workshops. If there is no effective design plan for the production of the mold shell, the reaction problem is not obvious when welding small products, and various shortcomings will appear when the power is high. In severe cases, immediately destroy the output power components.

All in all, the proper application of ultrasonic welding machine must cooperate with each other in six aspects: the heat transfer coefficient must be the melting point of the product workpiece, the two product workpieces must be fused, the total area of the joint must have certain regulations, welding The machine power must be considered, get rid of the wrong concept of the ultrasonic welding model, and the welding mold structure must be strictly tested.