Temperature dependent methods can be used to improve the cold start capability of fuel cell electric power generation systems. A method of ceasing operation of an electric power generation system improves the cold start capability and freeze tolerance of a fuel cell stack by reducing the amount of water remaining within the passages of the stack. The method involves purging one or more of the fuel cell stack oxidant and fuel passages at shutdown prior to allowing the fuel cell stack to drop to temperatures below the freezing point of water. Preferably purging at shutdown is conducted at a temperature below the stack operating temperature. Another method, used at start-up, involves directing a coolant fluid stream to the fuel cell stack only after a predetermined temperature above the freezing temperature of water is exceeded. Preferably, after freezing the fuel cell stack is heated to a temperature above its normal operating temperature before operation is commenced.

Methods for improving the cold starting capability of an electrochemical fuel cell

An apparatus and method for forming a textured polymeric film are disclosed. The apparatus includes a first roller and a second roller, wherein the first roller and the second roller may be configured to cooperatively form the textured polymeric film. In one embodiment, a limited portion of at least the first roller is heated, passively, actively, or by a combination of active and passive techniques.

System and method for forming textured polymeric films

The invention is directed to an apparatus for continuous fabrication of laminates comprising several layers of at least partially resin impregnated material webs which are extruded together. The material webs are taken off supply coils in the take off units and are subsequently stacked upon each other. The stacked material webs are then extruded into a laminate web in a double band press with application of area pressure and possibly heat. The laminate web is subsequently further processed in a grinding and cooling arrangement located downstream of the double band press, which consists of a grinding station and cooling station combined into one single device. Downstream of the grinding and cooling arrangement is a reel up arrangement for winding the laminate web upon supply coils or a transverse cutting station for subdivision of the laminate web into plates or panels.

Apparatus for continuous manufacture of laminates

In an apparatus for texturing an outer surface of an extruded thermoplastic resin article, a calibrator includes opposed and spaced apart sections for defining a gap which is determinative of a dimension for the article, an extruder feeds a formable, preshaped, extruded thermoplastic resin into the gap, and a carrier for supporting a textured material being positioned for contacting resin extruded from said extruder prior to calibrating said extruded resin wherein the textured material imparts a pattern to said extruded thermoplastic resin article.

Apparatus and process for texturing a thermoplastic extrusion

The invention relates to a method for shaping the surface of extruded profiles made of thermoplastic materials with a device which is profiled to the shaping surface such that it is complimentary to the demanded shaping dimensions and presses into the continuous profile. The invention provides a method and device with whose simple, economic and high uniformity permit a material-saving production of profiles while completely adhering to the required stability at the same time. To this end, the shaping device presses the desired shaping dimensions into the continuous profile such that the wall strength of the surrounding edges of the impressions is reduced and work-hardened. The profiles are cooled and shaped into a dimensionally stable state in such a way that the height of the impressions at least correspond to the halved wall strengths of the continuous profile.

Method and device for shaping the surface of extruded profiles

An arrangement for stamping an outer surface of a synthetic thermoplastic bar material in thermoplastic condition has a guiding element for a bar material, a rotary stamping tool with a working surface shaped in correspondence with a desired pattern to be stamped and rolling over the bar material, and a negative pressure element located in the region of the stamping tool and arranged for attracting the bar material against the working surface of the stamping tool.

Arrangement for stamping outer surface of shaped bar material

not available for EP0092745Abstract of corresponding document: US4511323An arrangement for stamping an outer surface of a synthetic thermoplastic bar material in thermoplastic condition has a guiding element for a bar material, a rotary stamping tool with a working surface shaped in correspondence with a desired pattern to be stamped and rolling over the bar material, and a negative pressure element located in the region of the stamping tool and arranged for attracting the bar material against the working surface of the stamping tool.

Blaum Franz

Papers

Arrangement for stamping outer surface of shaped bar material

Apparatus for embossing the surface of sectional bars

Vorrichtung zum praegen der oberflaeche von profilstaeben