Effect of Waste Micro-Particles on Metalworking Fluid Efficiency and Biodegradation During the Cutting Process

Area of Science:

• Industrial Microbiology
• Materials Science
• Environmental Engineering

Background:

• Metalworking fluids (MWFs) are prone to contamination from tool wear, corrosion, and microbial growth.
• Degraded MWFs pose risks to machinery, workplace hygiene, and worker safety.
• Effective decontamination strategies are crucial for sustainable machining operations.

Purpose of the Study:

• To identify and quantify microparticle contaminants and microbial populations in industrial MWFs.
• To evaluate the efficacy of filtration and ozonation as decontamination methods for MWFs.
• To propose an integrated approach for maintaining MWF quality and extending fluid lifespan.

Main Methods:

• Microparticle analysis using microscopy to classify size and composition (e.g., aluminum, iron oxides).
• Microbial quantification via culturing (CFU/mL) and identification of pathogenic strains.
• Filtration experiments using six nanofiber filters, assessing particle removal efficiency and flow rate.
• Ozonation treatment to evaluate microbial reduction, visual clarity, and pH changes.

Main Results:

• MWFs contained predominantly small microparticles (<50 µm) from tool wear and corrosion.
• High microbial contamination (>1000 CFU/mL) was detected, including a pathogenic strain.
• The Berry nanofiber filter showed 70.8% efficiency for particles ≥ 7.3 µm.
• Ozonation reduced viable microorganisms by over 95% and improved fluid clarity.
• Ozonation lowered pH from 9 to 8, within operational limits.

Conclusions:

• Integrated decontamination using filtration and ozonation offers a sustainable strategy for MWF management.
• This combined approach enhances fluid quality, reduces consumption and waste, and improves safety in machining.
• Effective microbial and particulate control is essential for extending MWF life and ensuring operational efficiency.