PREPARATION METHOD FOR LOW-DEFECT POLYACRYLONITRILE-BASED CARBON FIBER

The present disclosure discloses a preparation method of a low-defect polyacrylonitrile-based carbon fiber, and relates to the technical field of carbon fibers. The preparation method comprises: preparing a carbon fiber precursor; drawing the carbon fiber precursor to pass through a plurality of independent temperature-controlled pre-oxidation furnaces sequentially, the carbon fiber precursor in the pre-oxidation furnaces is given different degrees of drafting through the independent drive of each of the plurality of pre-oxidation furnaces, and the carbon fiber precursor is pre-oxidized to form a pre-oxidized tow; drawing the pre-oxidized tow to pass through a low-temperature carbonization furnace with a two-stage gas seal chamber structure to allow a low-temperature carbonization treatment to produce a low-carbon tow; drawing the low-carbon tow to pass through a high-temperature carbonization furnace with a tow dehumidification device to allow a high-temperature carbonization treatment to produce a high-carbon tow; drawing the high-carbon tow to pass through a one to two-stage surface treatment tank to allow a surface treatment; and the high-carbon tow is dried after sizing.