Sigracet 22 BB 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 215 um (microns). The hydrophobic treatment produces water repellent properties which prevent the highly porous carbon fiber backings from flooding and actively support the water management of PEM fuel cells. SGL BB is a great low-cost alternative to conventional woven carbon paper Gas Diffusion Layer (GDL) and Gas Diffusion Media materials.

The Sigracet Carbon Fiber Paper 22 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 automotive, PEM electrolysis

Sigracet 29 BC was discontinued and permanently replaced by Sigracet 22 BB.

Sigracet 22 BB Carbon Paper Property Sheet

Sigracet GDL Handling Instructions

Gas Diffusion Layer Properties
Material Type	Carbon Fiber Paper
Thickness	215 microns +/- 20 microns
Areal Weight	70 +/- 15 g/m²
Electrical Resistivity	< 10 mΩcm² (milliohms cm²)
Thermal Conductivity	0.30 W(m^-1)(K^-1)
Bending Stiffness (MD/TD)	1.5 / 0.9 N mm
Gas Permeability	1.2 Gurley sec
Compressibility	20% (@ 5psi, 1 MPa)
Water Contact Angle (MPL)	> 130°
Roughness (MPL side)	7.2 µm
Impurities (Fe, Co, Ni)	< 10 ppm
Tensile Strength	6.9 / 4.6 MPa (MD/TD)
Substrate PTFE Treatment	5%
Microporous Layer	Yes, on one side