Abstract: A method for embossing expanded graphite sheet material comprises removing at least a portion of the gas from within the material by exposing the material to a pressure less than atmospheric pressure, and then embossing the material. The pressure to which the material is exposed is preferably no greater than about 400 torr. An apparatus for embossing expanded graphite sheet material at a pressure less than atmospheric pressure comprises: an embossing device, a compression device adapted to urge the embossing device against the material, an embossing chamber comprising the at least one embossing device and adapted to receive the material and to be substantially gas-tight at least when the embossing device is urged against the material by the pressing device, and an evacuation device for reducing the pressure within the embossing chamber.

Abstract: An improved method for embossing expanded graphite sheet material including removing at least a portion of the gas from within the material by exposing the material to a pressure less than atmospheric pressure, and then embossing the material.

Abstract: An electric power generation system has components that improve the cold start capability and freeze tolerance of a constituent fuel cell stack. The components cooperate to reduce the amount of water remaining within the passages of the stack. The system includes a purge system that is connectable to the oxidant supply, the fuel supply and/or the coolant passages upstream of the stack. When the stack is shut down, the stack is disconnected from an external circuit, and purge fluid is directed by the purge system through the stack before the stack falls below the freezing point of water. In systems where the fuel and/or oxidant streams are humidified prior to their introduction into the stack, a humidifier bypass system may be provided in place of the purge system. The humidifier bypass system directs reactant fluid to the stack in fluid isolation from the humidifier, so that the inlet reactant streams are unhumidified.

Abstract: An improved embossing expanded graphite sheet material comprises removing at least a portion of the gas from within the material by exposing the material to a pressure less than atmospheric pressure, and then embossing the material. Preferably, the pressure to which the material is exposed is less than or equal to about 400 torr. An improved apparatus for embossing expanded graphite sheet material at a pressure less than atmospheric pressure comprises: at least one embossing device; at least one compression device adapted to urge the embossing device against the material; an embossing chamber comprising the at least one embossing device and adapted to receive the material, and to be substantially gas-tight at least when the embossing device is urged against the material by the pressing device; and an evacuation device for reducing the pressure within the embossing chamber. The atmosphere within the embossing chamber may comprise an inert gas, such as, for example, nitrogen, helium and argon.