Ultrasonic handheld spot welding joins two thermoplastic parts at localized points without a preformed hole or energy director. It produces a solid structural weld and is especially suitable for large parts or parts with complicated geometry or hard-to-reach joining surfaces. The horn has a pilot tip in spot welding, which melts through the top part and into the bottom portion to a predetermined depth when ultrasonic vibrations are applied. When vibrations cease, the melt from both parts flows together, forming a weld with the top side having a raised ring produced by the welding tip. The bottom layer of a spot welding joint has a smooth appearance. Spot welding can be performed with hand-held guns, single- or double-headed bench welders.
Common problems of traditional welding
- High-temperature welding is easy to cause damage to the welding surface and even deform the product in severe cases.
- The welding equipment is large, not easy to handle by hand, and unable to complete complex procedures.
- The welding mode is too single, the welding material is restricted, and the welding head cannot be replaced at will.
- Adhesives and fluxes are used for welding, the welding pollution is severe, and the welding strength is not high.
- Adhesives, studs, or other mechanical fixation are used when welding, which is inefficient and costly.
The technology of ultrasonic spot welding
When ultrasonic waves act on the surface of thermoplastic plastics, high-frequency vibrations of tens of thousands of times per second are generated. The ultrasonic energy is transmitted to the welding area through the weldment, and local high temperatures will be generated. Due to the poor thermal conductivity of plastics, heat is concentrated in the welding area, causing the surface of the plastic to melt rapidly. After a certain pressure is applied, it is integrated.
A hand-held ultrasonic spot welding machine can be used for welding, riveting, spot welding of films, fabrics, thermoplastic products, and inlay and edge pressing processes between metal parts and plastic parts.
Advantages of ultrasonic spot welding
The digital electric box automatically tracks the resonant frequency and adjusts the output frequency to match the handheld device. Once a fault is found, it stops working and gives an alarm. Most of the ultrasonic welding can be completed within 0.1-0.5 seconds.
Energy-saving and environmental protection
The welding surface is not damaged or deformed, without scratches and adhesive residues, avoiding using a large number of fixtures, fluxes, and adhesives, reducing labor and reducing costs.
Ultrasonic welding is solidified and formed, and the molecules are recombined to form a solid molecular chain. The strength of the weld can be close to the strength of the raw material.
Ultrasonic welding is very easy to realize automation. As long as the welding parameters are set, the welding can be carried out without preheating or cleaning.
Wide range of applications
Hand-held ultrasonic spot welding machines can be used for welding, riveting, spot welding of films, fabrics, and thermoplastic products, as well as inlay and edge pressing processes between metal and plastic parts.
Application of ultrasonic spot welding
Ultrasonic welding is an eco-friendly process that takes seconds, consumes very little energy, and reduces costs while maintaining high quality. The equipment fuses contact points on cell phones and other consumer electronics that are generally inaccessible with other welding methods. These techniques can be adapted to a wide range of commercial and industrial applications. In the food industry, the ultrasonic welding process is used to create a hermetic seal. It can fasten blister packs and facilitate various products, including toys, disposable lighters, pipettes, and intravenous catheters.
Ultrasonic welding is commonly used in the plastics, aerospace, and automotive industries to join similar materials. It is advantageous in the production of medical products. Since the process does not introduce exhaust or other contaminants and the welds do not degrade, the manufacturing equipment can be used in a clean-room environment.