Why Filter Media Selection Matters More Than Micron Rating

Understanding Filter Media and Its Effects on Fluid Filtration

Many buyers focus only on micron ratings when selecting filter media. But coolant filtration performance depends on several factors:

• Coolant chemistry
• Media structure (depth vs. surface filtration)
• Flow rate
• Particle size distribution

Industry guidance warns that selecting filter media solely on micron rating can lead to higher operating costs and poor filtration results.

The right approach is to match the filter media type to the specific application and contaminant load.

The PRAB Approach: Multi-Stage Fluid Filtration for Emulsified Coolants

PRAB designs fluid filtration systems around the principle that no single filtration method solves every coolant problem.

Instead, the most effective systems use a staged approach:

1. Magnetic separation to remove ferrous fines
2. Paper bed filters
3. Paper Bed Filters or roll media filtration for general solids removal
4. Advanced or membrane filtration for emulsified contaminants

This multi-stage approach:

• Extends coolant life
• Reduces disposal costs
• Improves surface finish
• Protects pumps and tooling

PRAB’s paper bed filters, for example, remove both ferrous and non-ferrous contaminants, allowing coolants to be reused rather than disposed of.

How to Choose the Right Filtration Media

When selecting filtration media for emulsified coolants, consider:

Key Factors

• Material being machined (steel, aluminum, cast iron, etc.)
• Type of coolant (synthetic, semi-synthetic, soluble oil)
• Particle size and load
• Flow rate and system size
• Desired coolant life and clarity

General Guidelines

The Bottom Line

For most metalworking operations using emulsified coolants:

Depth-type nonwoven roll media—often used in paper bed filters—provide the best balance of filtration efficiency, coolant life, and operating cost.

But the highest-performing systems combine:

• Magnetic separation
• Media filtration
• Advanced or membrane technologies

This integrated approach is the foundation of modern coolant recycling systems and closed-loop manufacturing environments.

Want to See the Right Media for Your Application?

PRAB offers:

• FREE Fluid testing
• Application-specific media selection
• Complete coolant recycling systems

Testing your coolant and chip samples is the fastest way to determine the ideal filtration media and system configuration.

About the Author

Paul Montgomery is the Marketing Manager at PRAB, Inc., a global manufacturer of engineered metal scrap handling, coolant recycling, and industrial wastewater treatment systems. With more than 30 years of experience across manufacturing, SaaS, custom development, healthcare, and education, he specializes in data-driven marketing that translates plant-floor performance into executive-level financial results. His work centers on total cost of ownership, automation integration, and closed-loop manufacturing strategies that help industrial companies reduce waste, conserve resources, and improve long-term profitability.