Controlled surface electrical resistance carbon fiber sheet product

A method of manufacturing a plurality of different value controlled resistivity carbon fiber sheet products employing [a] carbonizable , previously oxidized and stabilized fiber starting material;

• said method comprising [oxidizing and stabilizing the fiber starting material at an elevated temperature of the order of 220 degrees Centigrade to effect molecular aromatic rearrangement of the fibers,] forming [a] an oxidized and stabilized tow, stretching and breaking the stabilized tow, forming the stabilized stretched and broken fiber filaments into sliver comprised of, large bundles of discontinuous filaments in an untwisted condition, converting the sliver into roving, spinning the roving into a spun yarn, plying or twisting the spun yarn, weaving or knitting the plied and twisted spun yarn into fabric, and selectively partially carbonizing the fabric thus formed at [a] preselected elevated temperature values for a predetermined time period in an oxygen free atmosphere within a furnace having a continuously increasing temperature profile within the range from about 370 degrees Centigrade to about 1300 degrees Centigrade [by soaking the fabric at the preselected elevated temperature for the predetermined period of time] to provide a known preselected [surface] electrical volume resistivity to the partially carbonized fiber filament in the fabric corresponding to that value of electrical volume resistivity required to provide the preselected desired surface resistance for the finished fabric .

A method of manufacturing a plurality of different value controlled [resistivity] surface resistance carbon fiber sheet products employing [a carbonized] carbonizable previously oxidized and stabilized fiber starting material;

• said method comprising [oxidizing and stabilizing the carbonizable fiber starting material at an elevated temperature of the order of 220 degrees Centigrade to effect molecular aromatic rearrangement of the fibers,] selectively partially carbonizing the stabilized fibers at [an] elevated temperature values in an oxygen free atmosphere within a furnace having an increasing temperature profile extending over a temperature range from about 370 degrees Centigrade to about 1300 degrees Centigrade by soaking the stabilized fibers at a preselected elevated temperature for a predetermined period of time in accordance with a prescribed temperature-time-resistivity schedule to provide a preselected known electrical volume resistivity to the partially carbonized fibers corresponding to that required to provide the preselected desired surface resistance for the finished sheet products , processing the partially carbonized fibers into desired end sheet products having preselected desired surface electrical [resistivities] resistances , and wherein the steps of processing the carbonized fibers into a desired end carbon fiber sheet product include chopping the selectively carbonized fibers into bundles of fine fibers having a length of from 1/8 to 1 inch, supplying the chopped carbonized fibers to a mixer for mixing with water in [copious] quantities to form a slurry comprised of about 83% carbonized fibers, 14% cellulose, 2% polyvinylalcohol and the remainder a resin to result in a highly dilute solution wherein the [constitutents] constituents of the slurry exclusive of the water amount to about 0.12% of the overall slurry solution including water, adjusting the Ph factor of the overall slurry solution of a Ph factor of about 8-9 with ammonia, supplying the slurry solution to a wet lay paper formation process to form wet sheets of carbon fiber paper, conveying the wet sheets of carbon fiber paper to a series of dryer cans and taking up the sheets of dry carbon paper continuously on a take-up roll for storage and use.