Blast Nozzle Atomization for Static Control and Efficiency

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Blasting methods face challenges in preventing static electricity generation, which leads to abrasive adhesion issues and reduced productivity, especially in microfabrication where finer abrasives are used, and existing solutions like ionizers are costly, complex, and prone to maintenance issues, while wet blasting methods decrease processing efficiency and require additional washing and drying steps.

Innovation Solution

A blasting method that atomizes a small amount of liquid, typically water, at the blast nozzle's ejection port, creating a humid environment to prevent static electricity without wetting the workpiece, using a suction-type blast nozzle with a liquid introduction path and flow control means to ensure efficient atomization and evaporation, enhancing processing efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If an ionizer is provided to eliminate static electricity, then static electricity is removed, but the apparatus becomes expensive and requires frequent maintenance

Engineering Contradiction:
Improvestatic electricityVSAvoidapparatus complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The patent introduces a humidifier as an intermediary device that adds moisture to the compressed gas stream, which then neutralizes static electricity through a physical chemical process rather than requiring complex electrical components. The moisture acts as a mediator between the compressed gas and the abrasive particles, preventing static buildup without needing ionizer electrodes or power supplies.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces expensive, maintenance-intensive ionizer components with a simple, inexpensive humidification system using basic water reservoir and heating elements. The consumable resource (water) is continuously replenished rather than requiring maintenance of complex electrical components, effectively treating the static elimination function as a disposable solution.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

2Object-affected harmful factors

If wet blasting is used to prevent static electricity, then static electricity is eliminated, but processing efficiency decreases and additional washing/drying steps are required

Engineering Contradiction:
Improvestatic electricityVSAvoidprocessing efficiency
Core Design Contradiction:
Object-affected harmful factorsVSProductivity

Solution Approach 1:

The patent applies moisture locally and temporarily only at the point of abrasive ejection through the nozzle, rather than immersing the entire workpiece in water as in traditional wet blasting. The humidified compressed gas creates a localized humid environment around the abrasive stream, neutralizing static electricity only where needed during the blasting process, allowing the workpiece to remain essentially dry.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The patent uses a controlled amount of moisture—enough to prevent static electricity generation but less than traditional wet blasting. By partially humidifying the compressed gas rather than fully saturating it, the system achieves static elimination while minimizing water contact with the workpiece, thereby maintaining processing efficiency and eliminating the need for extensive post-processing drying steps.

Inventive Principle:
Principle #16Partial or excessive action

3Manufacturing precision

If finer abrasives are used for microfabrication, then manufacturing precision is improved, but abrasive adhesion due to static electricity increases

Engineering Contradiction:
Improvemicrofabrication precisionVSAvoidabrasive adhesion
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The patent applies humidification to the compressed gas before the abrasive particles are accelerated, creating a pre-humidified gas stream that surrounds the finer abrasives from the moment they enter the nozzle. This preliminary humidification prevents static electricity from building up on the fine abrasive particles during acceleration, addressing the adhesion problem before it can occur during the blasting process.

Inventive Principle:
Principle #10Preliminary action

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This method effectively prevents static electricity, improves cutting speed and efficiency, reduces abrasive consumption, and prevents workpiece warpage and temperature rise, maintaining the benefits of dry blasting while enhancing processing performance beyond conventional methods.

Implementation Method 1

atomizing the liquid by causing the liquid to contact or strike with the compressed gas flowing through the blast nozzle or the compressed gas ejected from the blast nozzle

Methodology Applied
Scientific EffectAtomization:

Implementation Method 2

The liquid introduced into the blast nozzle is atomized by contacting or striking the liquid with the compressed gas... creating a humid environment

Methodology Applied
Scientific EffectEvaporation: Evaporation

Implementation Method 3

an abrasive is ejected together with a compressed gas to perform processes on a workpiece including cutting, surface polishing, deburring and paint stripping

Methodology Applied
Scientific EffectImpact force: Impact Force

Implementation Method 4

static electricity is generated by friction that is created when the abrasive strikes with the workpiece

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3061567B1Blast machining method and blast machining device
Publication Date: 2024.03.20 FUJI MFG CO LTD
  • EP3061567B1 patent drawingFigure 1
  • EP3061567B1 patent drawingFigure 2A~2B
  • EP3061567B1 patent drawingFigure 3A~3B

AI summary

Provided is a blast machining method in which static electricity-preventing effects coexist with processed volume-increasing effects. A liquid such as water is introduced in relatively small volumes of 0.06 cc/min-150 cc/min to a blast nozzle (8) provided in a blast machining device. The introduced liquid is atomized by causing the liquid to collide with a high speed compressed gas stream flowing inside the blast nozzle (8) or a high speed compressed gas stream jetted from the blast nozzle (8). The atomized liquid is jetted towards the workpiece (W) along with the compressed gas and an abrasive. As a result of the jetted liquid evaporating easily because the liquid is atomized and jetted in this manner and the volume of liquid supplied is relatively small, humidity inside the work chamber increases and generation of static electricity is limited. Additionally, the workpiece is cooled by vaporization heat being consumed during evaporation and absorption of the impact energy of the abrasive that occurs as a result of the softening of the workpiece surface due to heat generated by collision with the abrasive is limited and processed volume (cut volume) is improved.