How to Choose Ultrasonic Cleaning Frequency

Why Does Frequency Affect Cleaning Performance?

Ultrasonic cleaning works by using high-frequency vibration to generate cavitation bubbles in the liquid.
When these bubbles collapse, they create an instant impact force that removes contamination from the surface.

• Lower frequency → larger bubbles and stronger cavitation impact.

• Higher frequency → smaller bubbles and gentler cleaning.

Therefore, frequency selection determines both the cleaning strength and cleaning precision.

Comparison of Cleaning Characteristics: 28 kHz, 40 kHz, 80 kHz, 120 kHz, and 1 MHz

A. 28 kHz

• Bubble size: Large

• Cleaning strength: Strong

• Cleaning precision: Coarse

• Feature: Strong impact for removing heavy contamination
  
  B. 40 kHz

• Bubble size: Medium

• Cleaning strength: Moderate

• Cleaning precision: Medium

• Feature: General-purpose standard frequency
  
  C. 80 kHz

• Bubble size: Small

• Cleaning strength: Gentle

• Cleaning precision: High

• Feature: Gentle cleaning for precision parts
  
  D. 120 kHz

• Bubble size: Smaller

• Cleaning strength: Gentle

• Cleaning precision: Higher

• Feature: Suitable for high-precision processes
  
  E. 1 MHz / 1000 kHz

• Bubble size: Extremely small

• Cleaning strength: Ultra-gentle

• Cleaning precision: Ultra-high

• Feature: Ultra-high-frequency micro-vibration cleaning

Characteristics of Each Frequency

B. 40 kHz: General-Purpose Standard Frequency
• Medium bubble size, making it the most commonly used industrial frequency.
• Balances cleaning power and safety, widely used in electronics, medical, and machinery industries.

C. 80 kHz: Precision Gentle Cleaning Type

• Finer and more evenly distributed bubbles, allowing cleaning without damaging the surface.
• The wavelength of 80 kHz is shorter, but the penetration ability is relatively lower.

A. 28 kHz: Strong Impact for Heavy Contamination
• Large bubbles and strong cavitation impact, suitable for thick oil contamination and surface contamination on metal parts.
• Not recommended for fragile or thin materials, as it may cause micro-damage.

D. 120 kHz: High-Precision Process Type
• Tiny and stable bubbles can remove fine particles and thin-film contamination.
• Cleaning strength is relatively weaker, and cleaning time is longer.

E. 1 MHz: Ultra-High-Frequency Cleaning Type
• Belongs to ultrasonic atomization-level cleaning, with almost no strong cavitation impact.
• Higher equipment cost and more complex control, mainly used for special processes.

Frequency Selection Recommendations

A. 28 kHz

• Applicable industries and applications: Molds, hardware, automotive and motorcycle parts, heavy oil contamination
  Cleaning requirements: Heavy oil removal, molds, and metal parts.

• Description: Strong cleaning power with high penetration, suitable for removing heavy contamination.
  
  B. 40 kHz

• Applicable industries and applications: Electronic parts, medical instruments, and general metal parts
  Cleaning requirements: General metals and electronic components

• Description: General-purpose design with stable cleaning performance.
  
  C. 80 kHz

• Applicable industries and applications: Optical lenses, plastic parts, and precision components
  Cleaning requirements: Optical lenses and plastic parts

• Description: Gentle cleaning that helps prevent surface damage.
  
  D. 120 kHz

• Applicable industries and applications: Semiconductor wafers, precision optics, and medical implants
  Cleaning requirements: Semiconductor and medical precision processes

• Description: Fine cleaning with high cleanliness requirements.
  
  E. 1 MHz / 1000 kHz

• Applicable industries and applications: Wafers, MEMS components, sensors, and nanoscale processes
  Cleaning requirements: Nanoscale fine structures and sensors

• Description: Ultra-high-frequency precision cleaning for advanced applications.

Choosing the right frequency determines the cleaning depth and gentleness.

Lower frequencies focus on cleaning power, while higher frequencies focus on precision.

Frequencies from 28 kHz to 2 MHz each have their own application range.

YONG JI Enterprise can help you design the most suitable high-efficiency ultrasonic cleaning system based on your process conditions and workpiece materials.

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