METHOD FOR INCREASING STRENGTH OF CARBON FIBER

摘要

PURPOSE:To increase the strength of a carbon fiber as a composite reinforcing material without damaging the carbon fiber, by subjecting to the fiber a treatment in which the fiber is allowed to pass through a plasma flame. CONSTITUTION:This method for increasing the strength of a carbon fiber comprises allowing the carbon fiber to pass through an intermediate temperature region of 350-600 deg.C in the tip part of a plasma flame for 0.1-1.0sec or through a low temperature region of 100-350 deg.C in the tip part for 0.1-1.5sec. When the treatment region is placed in the atmosphere, namely in the presence of 20-21% of oxygen gas, a large treatment effect is obtained.