Sigracet 24 and 25 Gas Diffusion Layer Property Sheet

Properties of SIGRACET® GDL 24/25PropertyThickness ?Areal WeightPorosityAir Permeability ¦Electrical Resistance(through plane) ?Unitmilµmoz/ft2g/m2%cm3/(cm2· s)mOcm2GDL 24 BA7.51900.18548460< 10GDL 24 BC9.32350.33100760.6< 12GDL 25 BA7.51900.134088210< 10GDL 25 BC9.32350.2886801.0< 12Broad Base. Best Solutions. Technische InformationAfter the introduction of our 200-micron thick GDL series GDL 20/21 in 2002, SGL Group has been fur-ther improving the series with respect to productionyield and product variability. We have introduced ournewest grades, GDL 24 and GDL 25, to the commer-cial market. SGL Group has invested heavily in this prod-uct development and has been contributing resourcesfrom a number of different and cross-functional parts of the organization. The result has been the launch ofour new grades GDL 24/25. Users have confirmed the excellent match of the properties:• Greatly improved homogeneity inter-lot and intra-lot.The overall variability has been shown to be betterthan +/– 10% (2 sigma)GDL 25GDL 24GDL 10FoilsGDL 35GDL 34Technische InformationSIGRACET®GDL 24 & 25 Series Gas Diffusion Layer? Under 0.25 N/cm2, sample diameter 13 mm¦ Gurley model 4118, 300 cc, 0.1 sq in orifice? 2-point measurement, circular (25 mm diam.) gold-plated contacts under pressure of 10 bar• Greatly improved surface flatness• Greatly reduced occurrence of faulty spots on a roll• Greater roll length• Best performance under various operating conditionsThe above list is not sacrificing any of the list of prop-erties which makes SGL Group’s GDL unique:• Produced and shipped as a continuous roll good• Utilizing low-cost nonwoven processes• Hydrophobic treatment of the substrate to the de-sired level by coating the bulk surfaces with PTFE• Coating of material grades with SGL Group’s uniquemicroporous layer for better membrane contact, water management and mechanical protection• Concept of lower and higher porosity (GDL 24: lower, GDL 25: higher porosity) to react with cell humidity level.The introduced product series GDL 24/25 is intendedto combine the required production robustness and theexcellent performance properties. Stack developersand assemblers are benefiting from the greatly im-proved characteristics.GradesWe supply SIGRACET Gas Diffusion Layers in roll form in lengths of 75 +/– 25 m. Our standardroll width is 45 cm, but we can split parent rolls into multiples thereof, i. e. 2 x 22.5 cm wide rolls, 3 x 15 cm wide rolls, etc. Sheets stamped to a specified geometry are also available if so desired.Substrate PTFE loadings are available from 0 to 30 wt%, but 5 wt% is standard.GDL “AA“ is our plain substrate with no value-added post-processing.GDL “BA“ is our hydrophobized substrate with a 5 wt% PTFE loading.GDL “BC“ is our hydrophobized substrate (5 wt% PTFE) with our standard Microporous Layer (MPL) on one side.® registered trademark of SGL Group companies 04 2007/1 2NÄ Printed in GermanyThis information is based on our present state of knowledge and is intended to provide general notes on our products and their uses. It should therefore not be construed as guaranteeing specific properties of the products described or their suitability for a particular application. Any existing industrial property rights must beobserved. The quality of our products is guaranteed under our “General Conditions of Sale”.Fuel Cell Components SGL TECHNOLOGIES GmbHPhone +49 8271 83-3360 fuelcellcomponents@sglcarbon.dewww.sglcarbon.comBy courtesy of HydrogenicsBy courtesy of NuveraUnique CharacteristicsOur GDL 24/25 nonwovens are of a 2-dimensional structure designed to have lower thickness, higher bending stiffness, lower compression set, and lower compressibility than GDL 10. GDL 24/25 is a further development towards thinner materials maintaining the properties of the GDL 20/21 series. GDL 24/25 has also greatly improved tolerances (thickness and areal weight) and a lower anisotropy factor between the machine and transverse directions.On request, we will advise you on maximum compression loads for use in bondingto Catalyst-Coated Membranes (CCMs) or assembling stacks. Gasket design alsoneeds to take the compression behavior into account.% PTFE 0 5 10 20 30Y A B C D EAA YA YC