US Patent 7090793 Preparation of fuel cell composite bipolar plate

A composite bipolar plate of polymer electrolyte membrane fuel cells (PEMFC) is prepared as follows: a) preparing a bulk molding compound (BMC) material containing a vinyl ester resin and a graphite powder, the graphite powder content of BMC material ranging from 60 wt % to 80 wt %, based on the compounded mixture; b) molding the BMC material from step a) to form a bipolar plate having a desired shape at 80–200° C. and 500–4000 psi, wherein the graphite powder is of 40 mesh–80 mesh.