20kHz 3000w Automatic Ultrasonic Spirometry Filter Welder Ventilator Welding

High Power 20Khz Ultrasonic Turntable Welding And Cutting Machine For Plastic Filter Welding

High power 20Khz ultrasonic turntable welding machine for plastic filter welding

Which plastic materials are suitable for ultrasonic welding?

1. To find out the weldability of materials that need ultrasonic welding, some materials are difficult to weld, and some cannot be welded. Plastics are divided into thermosetting and thermoplastic materials. Thermoset materials are not weldable. Thermoplastic materials are divided into
Shaped materials (such as ABS, PC, PMMA, AS, PS) and semi-crystalline materials (such as PET, PBT), amorphous materials are easy to ultrasonically weld, and semi-crystalline materials such as PPV nylon and POM are relatively difficult to weld. This
It is the basic idea of selecting materials.
2. Pay attention to the pre-processing process of welded plastic parts. Some materials may have additives during the injection molding process, such as glass fiber, talcum powder, color powder, etc. And pay attention to the specific issues of whether the moisture content of the material is enough to require drying, etc.
specific treatment;
3. The shape of the welding part: - Generally, there are standard designs, there are basic energy director, shearing shear joint, usually the basic type is divided into stepped design and tongue and groove design and so on.

Working principle of ultrasonic plastic welding machine

When the ultrasonic wave acts on the thermoplastic plastic contact surface, it will generate high-frequency vibration of tens of thousands of times per second. This high-frequency vibration reaches a certain amplitude, and the ultrasonic energy is transmitted to the welding area through the upper weldment. The acoustic resistance at the welded interface is large, so local high temperature will be generated. And due to the poor thermal conductivity of the plastic, it cannot be dissipated in time, and it gathers in the welding area, causing the contact surface of the two plastics to melt rapidly. When the ultrasonic wave stops working, let the pressure continue for a few seconds to make it solidify and form, thus forming a strong molecular chain to achieve the purpose of welding, and the welding strength can be close to the strength of the raw materials. The quality of ultrasonic plastic welding depends on the amplitude of the transducer welding head, the applied pressure and welding time = three factors, the welding time and welding head pressure can be adjusted, and the amplitude is determined by the transducer and the horn. The interaction of these three quantities has an appropriate value. When the energy exceeds the appropriate value, the melting amount of the plastic will be large, and the welding object will be easily deformed; if the energy is small, it will not be easy to weld firmly, and the applied pressure should not be too large. This optimum pressure is the product of the edge length of the welded part and the optimum pressure per 1mm of the edge.

The effect of amplitude on ultrasonic welding.

Amplitude is one of the most important parameters in ultrasonic welding machines. It has a decisive role in the magnitude of frictional power. At the same time, it has a very close relationship with the oxide film on the welding surface, the frictional heat generation on the joint surface, and the plastic flow layer. Therefore, it is very important to choose the appropriate amplitude. The amplitude of the amplitude is generally in the range of 5 to 256 nanometers. The smaller the power of the welding machine and the higher the vibration frequency, the lower the amplitude should be selected; when the weldment is thinner or the hardness is lower, a lower amplitude needs to be selected. The reason for this is that the magnitude of the amplitude is directly related to the moving speed of the weldment at the contact surface, and the relative moving speed determines the friction power, plastic flow and temperature.
When selecting an ultrasonic welding machine, the appropriate amplitude range should be selected. It should be pointed out here that within this range, selecting a large amplitude can effectively reduce the welding time, which is a good method for improving work efficiency.
If the amplitude of the ultrasonic welding machine is small, it needs to be considered when making the ultrasonic mold, and the amplitude transformation ratio of the ultrasonic mold should be appropriately increased.