How handheld ultrasonic spot welding gun works

spot welding machine

The handheld ultrasonic spot welding gun adopts ultrasonic plastic welding technology. The high-frequency electric energy is converted into mechanical vibration energy through the ultrasonic transducer, and then the mechanical vibration energy is transferred to the welding head after changing the amplitude through the banner device. When the welding head is close to the surface of the processed product, ultrasonic waves are automatically generated, and micro-amplitude high-frequency vibration is made on the surface of the processed product, and the friction with the surface of the processed product is converted into heat, and the processed product is melted and then welded. Welding operation is relatively more perfect for welding, and welding with different effects can be obtained by changing the welding head.

The composition of handheld ultrasonic spot welding gun

An ultrasonic generator (power supply)

ultrasonic power supply

The ultrasonic generator converts the 110VAC or 220VAC electrical supply current into a high frequency, high voltage electrical signal.

Ultrasonic power is divided into two kinds of simulation and numerical control; hcsonic adopts numerical control power has more advantages.

  • Track the primary resonance
    During ultrasound operation, as the temperature, power, and load ca resonance, frequencysonance may shift, and the ultrasound generator can automatically follow this frequency shift.
  • Lock onto the primary resonance
    All ultrasonic systems have a primary resonance. Also, there will be secondary (spurious) resonances. When the power supply starts, it must lock onto the primary resonance and ignore the secondary resonances.
  • Auto-adjust amplitude
    Most applications can be best controlled by controlling the output amplitude rather than the power. Amplitude should be regarded as the independent (input controlled) variable, and power should generally be regarded as the dependent (output resultant) variable.

An ultrasonic converter (transducer)

The ultrasonic converter utilizes the high-frequency electrical signal from the generator and converts it into linear, mechanical movement. This conversion occurs through the use of piezoelectric ceramic disks that expand when a voltage is applied.

Piezoelectric transducers for power ultrasonics are of the Langevin type — i.e., one or more piezoceramics that are mechanically compressed (prestressed) between a front a back driver.

ultrasonic transducer

An ultrasonic booster

Ultrasonic booster and round flange

The ultrasonic booster is a tuned component that mechanically adjusts the amount of linear vibratory movement from the converter to the required level for the specific application to produce optimal welding performance. The booster also provides a safe, non-vibrating location to clamp onto the welding tools.

An ultrasonic welding tool (horn/sonotrode)

The ultrasonic welding horn is a custom-made tool engineered to vibrate at a specific frequency. These tools are painstakingly designed using computer modeling technology for optimum performance and longevity. Ultrasonic tools must be tuned to match the frequency of the system. This tuning procedure requires consideration of the horn’s mass, length, and geometry. The common tool head diameter is 10mm.

ultrasonic spot welding gun

Longer service life

Transducer prestress

All piezoelectric transducers for ultrasonic welding are of the Langevin type — i.e., one or more piezoceramics that are mechanically compressed (prestressed) between a front driver and a back
driver.

Transducer cross section
Transducer cross-section
Transducer Relative axial amplitudes
Transducer Relative axial amplitudes

Because piezoceramics are weak in tension, a static compressive prestress must be applied to prevent the piezoceramics from experiencing tensile stresses when the transducer vibrates ultrasonically. Also, the prestress assures that the piezoceramic interfaces make good contact so that the acoustic waves are transmitted well with minimum loss. We use the most convenient center screw design.

A specific prestress can be obtained by tightening the transducer center screw to tighten the transducer. The traditional method is to use a torque wrench for tightening, but this parameter is
affected by many factors and often has deviations.

Prestress vs torque Langevin type transducers
Prestress vs. torque Langevin type transducers

When the tightening of the ultrasonic transducer is insufficient, its impedance is large, which will cause serious heat generation; when the tightening is excessive, it is easy to cause problems such as damage to the ceramic sheet (crystal crack) and durability. The transducer is the most important part of ultrasonic welding equipment. So it is essential to tighten the transducer and obtain the best prestress accurately.

Get the best prestress of the transducer
Get the best prestress of the transducer

Piezoelectric ceramic sheet

Piezoceramics are typically classified as "soft" or "hard." Hard piezoceramics are used for power applications. Among hard piezoceramics, there are two basic types, generally designated as PZT4 and PZT8 (PZT stands for lead-zirconate-titanate of which the piezoceramics are composed). Different manufacturers may have their own designations for these types, but the general performance is similar. Our device uses PZT8 piezoelectric ceramics, which has better relative performance.

Nominal piezoceramic properties at low electric field conditions
Nominal piezoceramic properties at low electric field conditions

Advantages of ultrasonic welding

  • Does not need an external heat source: The primary advantage of ultrasonic welding is that it doesn’t need an external heat source. The heat is self-generated between the materials.
  • Fast: Since the frequency of vibrations is very high; ultrasonic welding is one of the fastest welding methods available in the industry.
  • Possibility of automation: Ultrasonic welding being uncomplicated in many ways, is easy to automate. The ultrasonic machine comes with sensors that constantly monitor the temperatures.
  • Clean and strong joint: The contact surfaces melt/fuse upon welding, and it produces a very clean and strong joint.

Ultrasonic welding has many advantages when compared to traditional welding technologies. Many industries use ultrasonic welding due to these specific combinations of merits.

Application of ultrasonic spot welding machine

Ultrasonic welding is an eco-friendly process that takes seconds, consumes very little energy, and reduces costs while maintaining a high degree of 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 the manufacturing of 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 instrumental 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.

Ultrasonic spot welding machine tips

Ultrasonic welding is very effective at sealing or welding plastics. However, you cannot weld all types of plastics. ike metals, plastics also have different types. And it is essential to ensure that the plastics to be welded are chemically compatible. If you try welding polyethylene and polypropylene, they may melt together, but there will be no chemical bond. A chemical bond is important for creating strong weld joints. Another factor to keep in mind while welding any material through ultrasonic welding is maintaining a uniform contact area.[/box]

Attributes Parameter Attributes Parameter
Brand HCSONIC Item Model WW3505L
Maximum Power output 400W Frequency 35KHZ
Maximum Amplitude 2µm Working model Continuous, intermittent
Weldable materials Thermoplastic materials Welding Head Material Al, Steel
Welding Head Size 270*250mm  Driven Type Electric
Technical Support Video, mail, phone Warranty One year, except the horn
Full Set Weight 4.5KG Place of Origin China

Application: Used for welding masks, protective clothing, non-woven fabrics, automotive industry, and some plastic products.

hcsonic ultrasonic equipment naming rules
hcsonic ultrasonic equipment naming rules

 

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