Filter Media Types
Understanding the four primary filter media types: what they are, how they differ, and when to use each.
What It Is
Filter media is the material that performs the actual filtration—capturing contaminants while allowing clean fluid to pass. The media determines a filter's efficiency, service life, chemical compatibility, and cost. Four primary media types dominate industrial filtration: cellulose, synthetic, glass fiber, and wire mesh.
Why It Matters
Media selection directly impacts filtration performance. Two filters with identical dimensions and stated micron ratings may have dramatically different real-world performance based on media type. When cross-referencing filters, media type is a critical variable—not just dimensions and ratings.
Media Type Comparison
| Property | Cellulose | Synthetic | Glass Fiber | Wire Mesh |
|---|---|---|---|---|
| Efficiency | Moderate | Good | Excellent | Low-Moderate |
| Dirt Capacity | Excellent | Good | Good | Moderate |
| Water Tolerance | Poor | Excellent | Good | Excellent |
| Cost | Lowest | Moderate | Higher | Highest initial |
| Reusable | No | No | No | Yes |
| Typical Beta | 75-200 | 200-1000 | 1000-5000+ | 2-75 |
Cellulose Media
Cellulose (Paper-Based)
Made from wood pulp fibers. The most common and economical filter media for general industrial applications.
Advantages:
- • Lowest cost per element
- • Excellent dirt-holding capacity
- • Good for general hydraulic/lube applications
- • Widely available
Limitations:
- • Poor water tolerance (absorbs, swells)
- • Lower efficiency than synthetic/glass
- • Can shed fibers (media migration)
- • Limited chemical compatibility
Best for: General hydraulics, mobile equipment, cost-sensitive applications where water contamination is controlled.
Synthetic Media
Synthetic (Polyester, Nylon, Polypropylene)
Man-made fibers engineered for consistent performance. Bridges the gap between cellulose and glass fiber.
Advantages:
- • Excellent water tolerance
- • Higher efficiency than cellulose
- • Consistent fiber diameter (uniform pores)
- • Good chemical resistance
Limitations:
- • Higher cost than cellulose
- • Lower dirt capacity than cellulose
- • Lower efficiency than glass fiber
- • Temperature limits vary by polymer
Best for: Water-contaminated systems, outdoor equipment, applications requiring better efficiency than cellulose.
Glass Fiber Media
Glass Fiber (Microglass, Fiberglass)
Ultra-fine glass fibers providing the highest filtration efficiency available in disposable elements.
Advantages:
- • Highest efficiency (β ≥ 1000+ achievable)
- • Finest micron ratings (down to 1μm)
- • Excellent for servo systems
- • Minimal media migration
Limitations:
- • Higher cost
- • More fragile than other media
- • Can be damaged by pressure spikes
- • Not all fluids compatible
Best for: Servo valve protection, high-pressure systems, critical cleanliness requirements, aerospace.
Wire Mesh Media
Wire Mesh (Stainless Steel, Bronze)
Woven metal screen providing coarse filtration with the advantage of being cleanable and reusable.
Advantages:
- • Cleanable and reusable
- • Excellent chemical compatibility
- • High temperature tolerance
- • Long service life
Limitations:
- • Coarse filtration only (25μm+)
- • Low efficiency (surface filtration)
- • High initial cost
- • Requires cleaning infrastructure
Best for: Suction strainers, high-temperature applications, coarse pre-filtration, systems where cleaning is practical.
What Must Be Verified
When selecting or cross-referencing filters, verify media compatibility:
- • Fluid compatibility: Some media degrade in certain fluids
- • Temperature range: Media have operating limits
- • Water presence: Cellulose fails in wet systems
- • Required efficiency: Match media to beta ratio needs
- • Collapse/burst strength: Glass fiber is more fragile
Common Misconceptions
"All 10-micron filters are equivalent regardless of media"
A cellulose 10μm filter may achieve β = 75 while a glass fiber 10μm filter achieves β = 1000. Same rating, 10x difference in particles passing through.
"Glass fiber is always the best choice"
Glass fiber excels at efficiency but costs more, has less dirt capacity, and may be overkill for applications that don't need ultra-fine filtration.
Failure Modes and Risks
Media-Related Failures:
- Cellulose in wet systems: Media swells, collapses, or disintegrates—releases contaminant downstream
- Media migration: Loose fibers enter system, damage sensitive components
- Chemical attack: Incompatible fluids degrade media structure
- Pressure spike damage: Fragile media ruptures under surge conditions
Frequently Asked Questions
What is filter media?
Filter media is the material inside a filter element that actually captures contaminants. It determines the filter's efficiency, dirt-holding capacity, chemical compatibility, and service life. Common types include cellulose, synthetic fibers, glass fiber, and wire mesh.
Which filter media is best?
There is no universally 'best' media—each type has advantages for specific applications. Glass fiber offers the highest efficiency. Cellulose provides the best value for general use. Synthetic offers good efficiency with water tolerance. Wire mesh is reusable. Match media to your application requirements.
Can I switch from cellulose to synthetic media?
Often yes, but verify compatibility first. Synthetic media typically has higher efficiency and better water tolerance, but also higher cost. Ensure the replacement filter matches all other specifications (dimensions, micron rating, beta ratio, flow capacity) before switching.
Why does media type matter for cross-referencing?
Two filters with identical dimensions and micron ratings may perform differently if media types differ. Glass fiber may achieve β ≥ 1000 where cellulose only achieves β ≥ 75 at the same micron rating. Media type affects efficiency, dirt capacity, and chemical compatibility.
What is 'media migration'?
Media migration occurs when fibers or particles from the filter media itself break loose and enter the fluid stream. High-quality filters are designed to minimize migration. It's especially critical in servo valve applications where even filter-origin particles can cause problems.
Related Resources
Need Help Selecting Filter Media?
Our specialists can recommend the right media type for your application, fluid, and performance requirements.