Controlled resistivity carbon fiber paper and fabric sheet products and method of manufacture

Claim 1

A method of manufacturing a plurality of different value controlled resistivity carbon fiber sheet products employing a carbonizable 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 carbonizing the oxidized and stabilized fiber starting material for a predetermined time period in an oxygen free atmosphere within a furnace at a selected temperature within a temperature range from 370 degrees Centigrade to about 1300 degrees Centigrade by soaking the stabilized fiber starting material at the selected temperature for the predetermined period of time to provide a desired electrical resistivity to the carbonized fibers, and thereafter processing the carbonized fibers into desired electrical resistivity carbon fiber sheet products having the form of non-woven paper or woven or knitted fabric sheet products having preselected desired surface electrical resistivities.

Claim 2

A method of manufacturing a plurality of different value controlled resistivity carbon fiber sheet products employing a carbonizable 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 carbonizing the oxidized and stabilized fiber starting material for a predetermined time period in an oxygen free atmosphere within a furnace at a selected temperature within a temperature range from 370 degrees Centigrade to about 1300 degrees Centigrade by soaking the stabilized fiber starting material at the selected temperature for the predetermined period of time to provide a desired electrical resistivity to the carbonized fibers, and thereafter processing the carbonized fibers into desired electrical resistivity carbon fiber sheet products having the form of non-woven paper or woven or knitted fabric sheet products having preselected desired surface electrical resistivities.

Claim 12

A method of manufacturing a plurality of different value controlled resistivity carbon fiber sheet products employing a carbonizable 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 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 slectively carbonizing the fabric thus formed at a preselected elevated temperature for a predetermined time period in an oxygen free atmosphere within a furnace having a continuously increasing temperature profile within the range from 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 preselected surface electrical resistivity to the carbonized fabric.

Claim 13

A method of manufacturing a plurality of different value controlled resistivity carbon fiber sheet products employing a carbonizable 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 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 slectively carbonizing the fabric thus formed at a preselected elevated temperature for a predetermined time period in an oxygen free atmosphere within a furnace having a continuously increasing temperature profile within the range from 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 preselected surface electrical resistivity to the carbonized fabric.

Claim 17

A method of manufacturing a plurality of different value controlled resistivity carbon fiber sheet products employing a carbonized 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 carbonizing the stabilized fibers at an elevated temperature in an oxygen free atmosphere within a furnance having an increasing temperature profile extending over a temperature range from 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 electrical resistivity to the carbonized fibrs, processing the carbonized fibers into desired end sheet products having preselected desired surface electrical resistivities, 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 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.

Claim 18

A method of manufacturing a plurality of different value controlled resistivity carbon fiber sheet products employing a carbonized 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 carbonizing the stabilized fibers at an elevated temperature in an oxygen free atmosphere within a furnance having an increasing temperature profile extending over a temperature range from 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 electrical resistivity to the carbonized fibrs, processing the carbonized fibers into desired end sheet products having preselected desired surface electrical resistivities, 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 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.