What's Ultrasonic Spray Coating?

Ultrasonic atomization spraying technology is an advanced process that uses high-frequency ultrasonic vibrations to convert liquid into micron to nanometer droplets and forms a uniform coating through controlled deposition. Compared with traditional pressure spraying, electrostatic spraying and other technologies, ultrasonic atomization spraying has the advantages of controllable droplet size, high material utilization rate, and good coating uniformity. It is widely used in electronic manufacturing, biomedicine, new energy, precision optics and other fields. This article will introduce the working principle, system composition, key parameters and industry applications of ultrasonic atomization spraying equipment in detail.

1. Working principle of ultrasonic atomization spraying

1.1 Basic physical mechanism

The core principle of ultrasonic atomization spraying is to use a piezoelectric transducer to convert high-frequency electrical signals (usually 20kHz-3MHz) into mechanical vibrations, so that the liquid forms capillary waves (Rayleigh waves) on the ultrasonic vibration surface. When the vibration energy exceeds the surface tension of the liquid, the droplets peel off from the wave crest to form uniform atomization.

Key physical processes:

Thin liquid film formation: The liquid forms a micron-level thin film on the surface of the ultrasonic vibrator through the liquid supply system.

Capillary wave excitation: High-frequency vibration causes standing waves on the surface of the liquid film (wavelength λ ≈ 2π√(γ/ρf²), γ=surface tension, ρ=density, f=frequency).

Droplet peeling: When the amplitude reaches the critical value (A > λ/2π), the droplets detach from the wave crest to form droplets (particle size d ≈ 0.34λ).

2. Core components of the equipment

2.1 Ultrasonic generator:

Provides high-frequency electrical signals (1–10MHz), with a power of usually 10–500W.

2.2 Piezoelectric transducer:

Commonly used PZT ceramics, convert electrical energy into mechanical vibrations.

2.3 Atomizing nozzle:

Material: titanium alloy or ceramic, surface microstructure design affects the atomization effect.

2.4 Liquid supply system:

Precision metering pump controls flow (0.1–100mL/min).

2.5 Motion platform:

Robotic arm or XYZ guide rail to achieve automated spraying (accuracy ±5μm).

3. Typical application areas

Electronics industry: flexible circuits, solar cell electrode spraying.

Biomedicine: drug-coated stents, wound dressing preparation.

New energy: fuel cell catalyst layer, lithium battery electrode coating.

Optical coating: AR/VR lens anti-reflective coating.