ultrasonic plastic welding process

When the ultrasonic wave acts on the thermoplastic plastic contact surface, it will produce tens of thousands of high-frequency vibration per second. This kind of high-frequency vibration reaches a certain amplitude. The ultrasonic energy is transmitted to the welding area through the upper welding piece. Because the acoustic resistance of the welding area is large at the interface of two welding, local high temperature will be produced. Because of the poor thermal conductivity of the plastics, they can not be released in time, and gather in the welding area, resulting in the rapid melting of the two plastic contact surface, plus a certain pressure, so that it merges into one. When the ultrasound stops, the pressure lasts for a few seconds to solidify, forming a strong chain of molecules that can be welded to a strength close to that of the raw material. The quality of ultrasonic plastic welding depends on the amplitude of the transducer welding head, the pressure and the welding time. The welding time and the welding pressure can be adjusted, and the amplitude is determined by the transducer and the horn. When the energy exceeds the appropriate value, the melting amount of plastics is large, and the weld is easy to deform; if the energy is small, it is not easy to weld firmly, and the pressure can not be too large. The optimum pressure is the product of the optimum pressure on the side length and edge of the welded part of each 1mm.

Ultrasonic welding method

1. Welding method: Ultrasonic vibration is transmitted to the weldment along with the welding head. Because of the large acoustic resistance at the two weldments, local high temperature is produced, and the interface of the weldment is melted. Under certain pressure, two welds can achieve beautiful, fast and solid welding effect.

2. Embedding: insert nuts or other metals into plastic parts. First, the ultrasonic wave is transmitted to the metal, which is vibrated at high speed, so that the metal is directly embedded in the molding plastic. At the same time, the plastic is melted and solidified to complete the embedding.

3. Riveting method: In order to join metal with plastic or two different plastic pieces, ultrasonic riveting method can be used to make the welding parts not easy to embrittle, beautiful and strong.

4. Spot welding: Two large plastic products are spot welded by small welding heads, or the whole row of tooth-shaped welding heads are directly pressed on two plastic workpieces, so as to achieve spot welding effect.

5. Forming method: The plastic workpiece is melted and molded instantly by ultrasonic wave. When the plastic solidifies, the metal or other plastic materials can be made firm.

6. Removal method: Using the special design method of welding head and base, when the plastic workpiece just shot out, directly pressed on the plastic trunk, through ultrasonic transmission to achieve the effect of removal.