Woven vs Knitted Nickel Mesh: Technical Comparison

Woven nickel mesh is for the catalyst layer where ordered geometry controls current distribution. Knitted nickel mesh is for the porous transport layer where elastic compressibility maintains contact pressure. They are complementary materials — not competing ones. Confusing the two in an electrode specification is the most common substrate selection error we see in electrolyzer OEM RFQs.

TL;DR — Woven mesh (30-60 mesh, 35-55% OA, rigid) for catalyst support. Knitted mesh (660-1150 g/m2, 85-98% porosity, elastic) for PTL. Woven = ordered geometry, uniform current. Knitted = 3D spring-back, gas release. Two different manufacturing processes, two different cell positions.

Two Manufacturing Processes, Two Different Mechanical Behaviors

Woven nickel mesh is produced on precision industrial looms by interlacing warp and weft wires at right angles. The result is a flat, two-dimensional grid with repeatable aperture geometry — every unit cell is identical. Mesh count is verified by optical inspection on every roll. Wire diameter is verified by laser micrometer. This ordered structure is the correct choice for the catalyst support substrate, where current density must be identical at every point on the electrode surface. Standard specification: 30-60 mesh per inch, 0.19-0.30 mm wire diameter, plain weave (1/1) for maximum aperture uniformity, Ni200 or Ni201 grade per ASTM B162.

Knitted nickel mesh is produced on industrial knitting machines by interlooping a single continuous nickel wire into a three-dimensional textile structure. The loop geometry creates a compressible, elastic material — it acts as a spring. Under 5-15 bar stack compression, knitted mesh compresses and maintains electrical contact. When compression is released, it recovers. This spring-back behavior is essential for the porous transport layer between the bipolar plate and electrode. Standard specification: 660-1150 g/m2 packing density, 85-98% volumetric porosity, single jersey knit (lightweight, elastic) or interlock knit (crush-resistant, for stacks above 1 m2 active area), Ni201 grade.

Selection Criteria: Which One Where

Requirement	Choose Woven	Choose Knitted
Uniform aperture geometry (current distribution)	Yes — ordered weave pattern	No — random loop structure
Elastic compressibility (PTL function)	No — rigid under compression	Yes — spring-back behavior
Geometric open area 35-55%	Yes — standard range	No — volumetric porosity is higher
Volumetric porosity 85-98%	No — 2D structure	Yes — 3D loop structure
Burr-free surface for diaphragm protection	Yes — electropolished available	N/A — no sharp wire ends
High surface area for catalyst coating	Yes — ordered anchor points	No — smooth curved wire surface
Dimensional stability under zero compression	Yes — rigid grid	No — compresses under load

Bottom line: Woven mesh for the catalyst support substrate — where ordered geometry, uniform current distribution, and diaphragm protection are the primary requirements. Knitted mesh for the porous transport layer — where elastic compressibility, gas bubble release, and contact pressure maintenance under stack compression are the primary requirements. They are complementary materials designed for two different engineering problems in the same cell.