United Technologies Corporation

International Fuel Cells, LLC

J Harold Smith

Richard D Breault

Glen J Goller

An apparatus for making composite sheets that are homogeneous, dense, and have an even surface. The apparatus comprises an oscillating plate unit that vibrates in a direction transverse to a belt means. Composite pre-mix is deposited on the conveyor belt which draws it under the oscillating plate. The oscillating plate has three sections: a curved plate section; an inclined plate section and a flat plate section. The composite pre-mix is metered by the curved plate section, compacted by the inclined plate section and maintained compacted by the flat plate section. These thus formed composite sheets may be cured and are particularly adapted for use in fuel cell structures such as electrode substrates.

Apparatus for making composite sheets

A process for fabricating a resin bonded carbon fiber article, and in particular electrochemical cell electrode substrates and the like requiring different mean pore sizes in different areas, involves simultaneously heating and compacting different mixtures of carbon fibers and resin in different areas of an article forming mold, wherein the carbon fibers in each of the different mixtures have different, known bulk densities. The different bulk densities of the carbon fibers in the mixtures are chosen to yield the desired mean pore sizes and other properties in the article after heating and compacting the mixtures. Preferably, the different bulk densities are obtained using different carbon fiber lengths in the molding mixtures. The process is well suited to forming ribbed electrode substrates with preselected optimum mean pore sizes, porosities, and densities in the ribs, the webs connecting the ribs, and in the edge seals.

Process for fabricating ribbed electrode substrates and other articles

In fabricating sheet material with closely spaced parallel ribs on one side, a mold with ribbed shaped grooves is uniformly filled with a loose, dry molding material using a coater with a plurality of adjacent blades extending therefrom with the blade tips parallel to and preferably in contact with the mold top surface. The coater is swept across the mold top surface and the blades distribute and compress the molding material into the mold grooves. The invention is particularly useful for molding materials with high fiber content which are difficult to pack uniformly and with sufficient density into the mold.

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Amherst, MA, United States of America

J Harold Smith