Titanium fiber felt is a sintered sheet made from titanium fibers. In proton exchange membrane (PEM) water electrolysis, a porous titanium component is often discussed as part of the anode-side porous transport layer (PTL). That role is different from the catalyst layer that supplies the active reaction surface. A useful specification starts by naming the material form, then recording porosity, thickness and any coating or interface requirements separately.
Felt is not mesh and not foam
A fiber felt uses a bonded fiber network. Woven titanium mesh is specified by wire diameter, mesh count and weave. Titanium foam uses a cellular pore structure; HuiRui lists foam porosity of 28%–50% on that product page. Substituting one name for another on a drawing creates avoidable sampling mistakes. Choose the structure your design actually calls for, then agree dimensions and acceptance checks.
HuiRui titanium fiber felt is listed with titanium content above 99.50%, a porosity range of 50%–75% (customizable), and thicknesses that include 0.20, 0.25, 0.30, 0.40, 0.50, 0.60, 0.80 and 1.00 mm, with further options discussed on request. Those figures describe the felt substrate as listed for quotation; they are not a claim of finished-cell performance.
What porosity and thickness each describe
Porosity is the void fraction of a defined bulk volume. Thickness is the sheet depth. Two felts can share a similar porosity and still differ in fiber diameter, packing and surface finish. When a drawing or project standard states a thickness condition, keep that context on the enquiry. Free thickness and thickness under a stated load are not interchangeable labels; only cite a load condition if your documents already define it.
For PEM anode assemblies, public technology assessments treat the PTL as a component that affects mass transport and electrical contact at the cell level. The same assessments note that titanium PTLs often rely on precious-metal interface coatings to limit titanium oxidation and contact resistance. That distinction matters in an enquiry: bare felt, coated substrate and a complete catalyst-coated electrode should be identified as different items. For electrolyzer-type framing, see HuiRui’s guide to ALK, PEM, AEM and SOEC.
Separate the substrate from coatings and catalyst
A titanium felt sheet, a coated titanium transport layer and an iridium-based catalyst layer answer different questions. DOE’s water electrolysis technology assessment discusses titanium transport layers, their interfaces and catalyst materials as related but separate topics. When you request material for evaluation, state whether you need:
- an uncoated titanium fiber felt sheet for structure or sample comparison;
- a coating requirement (material, faces, and how loading or thickness will be defined); or
- only a substrate, with the catalyst layer supplied elsewhere.
Do not infer coating presence from the words “titanium felt” alone.
How porosity and thickness enter a quotation
You can contact HuiRui with an application note, approximate size, a sketch or a drawing even if the full specification is not yet decided. The items below are helpful when you already have them; they are not a prerequisite for a first reply:
- titanium grade or documentation requirement;
- target porosity and how it will be checked (if known);
- target thickness and any measurement condition already stated on your drawing (if known);
- sheet length × width or a cut-part drawing;
- quantity, sample versus production intent;
- electrolyte or duty notes only insofar as they affect material selection (PEM anode PTL, mechanical sample, etc.);
- any coating, flatness, edge or inspection records required by the project.
Not every combination of porosity and thickness is interchangeable. Availability, tolerances and sample terms are confirmed for the selected specification rather than assumed from a product name. A firm quotation still needs agreed dimensions, quantity and duty conditions once those are ready.
Related titanium forms on the same site
If the drawing specifies intersecting wires, review woven titanium wire mesh. If it specifies a cellular titanium sheet, review titanium foam. For a nickel fiber network used in other electrochemical contexts, compare nickel fiber felt, which is a different base metal and should not be treated as a titanium PTL substitute.
Practical takeaway
Read porosity and thickness as substrate descriptors. Keep coatings and catalyst layers on separate lines in the enquiry. Match the material form—felt, woven mesh or foam—to the structure on the drawing. Then confirm feasible combinations, inspection records and sample terms before treating any list value as a finished-stack result.
For the distinction between porosity, pore size and surface contact, see our titanium felt pore structure guide.
You’re welcome to contact HuiRui with a short description of your PEM or titanium-felt requirement, a preferred thickness/porosity window, or a drawing. A detailed checklist can be completed later.
References
- HuiRui Titanium Fiber Felt product page (listed substrate specifications used above)
- HuiRui Titanium Foam product page (listed foam porosity range)
- U.S. DOE, Hydrogen Shot: Water Electrolysis Technology Assessment (PDF) — titanium PTLs, interfaces and precious-metal coatings discussion
- U.S. DOE NEPA CX-031202, Advanced Porous Transport Layer Design and Manufacturing for PEM Electrolyzers (determination PDF) — coated titanium PTL R&D context; not a performance claim for HuiRui products
- HuiRui guide: Hydrogen Electrolyzer Types: ALK, PEM, AEM and SOEC