Inside the World of the sintered metal fiber felt filter
If you work around melt filtration, polymer plants, or hot gas cleanup, you’ve probably heard engineers rave about metal fiber felt. To be honest, I used to think it was overhyped—until I saw what a good sintered metal fiber felt filter does in a messy PTA line. The media (often sold as “Sintered Felt Web”) combines ultrahigh porosity with solid-state diffusion bonding, so you get fine capture without the fragility of papers or meshes. The manufacturer notes “a highly uniform structure and ultrahigh porosity,” which matches what many customers say in trials.
How it’s made (short version)
Materials: 316L is the workhorse; 304L, 310S, Inconel, and Hastelloy show up for harsh chemistries. Process: random-lay metal fibers (≈2–40 μm diameter) are formed into a nonwoven mat, then sintered (often hydrogen or vacuum furnace, ≈1100–1350°C) to diffusion-bond contact points. Post steps can include calendaring, multi-layer stacking for graded porosity, seam welding into cartridges, and pleating. Testing includes bubble point and permeability (ASTM F316), pore size/porosity (ASTM D4404), and multi-pass efficiency (ISO 16889) for liquid service.
Why users switch
- High dirt-holding: deep, open structure; surprisingly low ΔP rise.
- Thermal stability: up to around 600°C in air; great for hot gases.
- Cleanability: backflush, ultrasonic, steam-in-place; service life can be years.
- Mechanical strength: resists collapse where polymer gels cause pressure spikes.
Specs at a glance (typical)
| Media | 316L stainless (also 304L/310S/Inconel/Hastelloy on request) |
| Nominal ratings | ≈3, 5, 10, 20, 40 μm (real-world use may vary by fluid) |
| Thickness | ≈0.3–1.2 mm per layer; multilayer gradients available |
| Porosity | ≈70–85% |
| Max temp | Up to ≈600°C (air), ≈300°C typical liquids |
| Differential pressure | Continuous ≈0.6 MPa; burst/implosion per design |
| Cleaning | Backwash, solvent, ultrasonic, air/steam blowback |
Applications
Polymer melt (PET/PA/PP), fine chemicals, catalytic recovery, hot gas dust removal, hydraulic oils, solvent clarification, aerospace bleed air, and yes—additive manufacturing powder recovery. In fact, a sintered metal fiber felt filter often replaces disposable depth media once the ROI on cleaning cycles is proven.
Real test notes
In water at 25°C, a 5 μm grade felt (1 m² media) showed initial ΔP ≈0.05 bar at 1,000 L/h; multi-pass β10 ≥ 200 per ISO 16889. Bubble point measured per ASTM F316 aligns with a mean flow pore ≈12–18 μm for that build. Your mileage will vary with viscosity and fines loading, of course.
Vendor landscape (quick comparison)
| Vendor type | Certs | MOQ | Lead time | Notes |
|---|---|---|---|---|
| OEM (China) | ISO 9001; RoHS/REACH statements | Around 10–50 pcs | 2–4 weeks | Strong customization; competitive pricing |
| Global brand | ISO 9001/14001; detailed validation packs | 1–10 pcs | 4–8 weeks | Excellent documentation; premium cost |
| Trader/Integrator | Varies | Flexible | Depends on source | Easier sourcing; mixed technical depth |
Customization checklist
- Alloy, fiber diameter, and layer count (graded porosity).
- Pleat height/pack, core/cage/boss materials, weld style.
- Cartridge sizes, discs, cones, candles; end caps per DIN/ANSI.
- QA pack: material certs, F316 bubble point, ISO 16889 curves.
Two quick case notes
A polyester plant swapped to a sintered metal fiber felt filter on a 20 μm grade and cut changeouts from weekly to quarterly; ΔP stabilized after three backwashes. Another client in solvent recovery reported 30–40% longer run time and easier steam cleaning—“less gunk baked in,” as their maintenance lead put it.
Product/Origin: Sintered Felt Web, Rm. C-1301, Hyde Park Plaza, No. 66 Yuhua W. Road, Shijiazhuang, 050056 China.
Authoritative references
- ASTM F316 – Standard Test Methods for Pore Size Characteristics of Membrane Filters by Bubble Point and Mean Flow Pore Test.
- ISO 16889 – Hydraulic fluid power filters – Multi-pass method for evaluating filtration performance.
- ASTM D4404 – Standard Test Method for Pore Volume and Pore Volume Distribution by Mercury Intrusion Porosimetry.
- ISO 9001:2015 – Quality management systems — Requirements.
POROYAL is dedicated to the research and development of powder sintered porous filter technology, establishing itself as a leading innovator in advanced porous material solutions.Titanium and plastic filters POROYAL engineers deliver high-value engineering solutions to address complex product design challenges across diverse industries, including petrochemical, oilfield, water treatment, food & beverage, pharmaceutical, chemical processing, medical devices, vacuum conveying, and other specialized applications.Metal porous filter Our expertise encompasses comprehensive liquid-solid and gas-solid separation technologies tailored to meet customer-specific requirements.At POROYAL, we function as an integrated enterprise comprising four specialized divisions—dedicated to the development of Metal Sintered Porous Filters, Plastic Sintered Porous Filters, Metal Fibers, and Medical & Laboratory filtration solutions. Metal Porous Filters Manufacturer
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