Sigracet 28 BC is a non-woven carbon paper with a Microporous Layer (MPL) that has been PTFE treated to 5 wt%. It has a total thickness of 235 µm (microns). The hydrophobic treatment produces water-repellent properties that prevent the highly porous carbon fiber backings from flooding and actively support the water management of PEM fuel cells. SGL 28 BC is a great low-cost alternative to conventional woven carbon paper Gas Diffusion Layer (GDL) materials.

The Sigracet Carbon Fiber Paper 28 Series is intended to combine the required production robustness and the excellent performance properties. Stack developers and assemblers are benefiting from the following greatly improved characteristics:

Greatly improved homogeneity inter-lot and intra-lot. The overall variability has been shown to be better than +/- 10% (2 sigma)
Greatly improved surface flatness
Greatly reduced occurrence of faulty spots on a roll
Best performance under various operating conditions
Recommended Applications: PEMFC stationary, PEMFC automotive

Sigracet 28 BC Carbon Paper Property Sheet

Sigracet 20 and 30 Series Carbon Paper Property Sheet

Sigracet Carbon Fiber GDL White Paper

Sigracet GDS 2D Recommended Applications

Sigracet GDL Handling Instructions

Sigracet AB, BA, BC+ Series GDL MSDS

Gas Diffusion Layer Properties
X-Material Type	Carbon Fiber Paper
Thickness	235 microns +/- 25 microns
Areal Weight	105 +/- 10 g/m²
Bending Stiffness (MD/TD)	1.7 / 1.2 N mm
Gas Permeability	4.5 Gurley sec
Compressibility	ca. 11% (at 1 MPa)
Electrical Resistivity (through plane)	< 11 mΩcm² (milliohms cm²)
Water Contact Angle (MPL)	> 130°
Roughness (MPL side)	6.4 µm
Impurities (Fe, Co, Ni)	< 10 ppm
Tensile Strength	6.6 / 5.1 MPa (MD/TD)
Substrate PTFE Treatment	5%
Microporous Layer	Yes, on one side
Other Plate Properties
Thermal Conductivity	0.38 W(m^-1)(K^-1)