The invention relates to a detection method for the cross section of a
fiber. The detection method comprises the following steps: 1, horizontally laying the
fiber on a film, sticking two
metal plates between the
fiber and the film, fixing the two
metal plates,
drying, cooling, carrying down the fiber from the film to obtain an impression picture of the longitudinal cross section of the fiber on the film; and 2, adhering the fiber to the bottom of a container by an
adhesive, adding a resin mixture to the container,
drying to polymerize the resin mixture, cooling at
room temperature,
slicing toobtain a slice, adhering the slice to a slide glass, and putting the slide glass in
cedar oil for the
microscope observation. The detection method of the invention has the advantages of simplicity, no new
equipment requirement, and realization of the large scale application. Compared with the direct
microscope observation, the method of the invention allows the obtained field depth to be better, complete information of the cross section of the fiber to be once obtained, and influences of dyes of the surface of the fiber to be eliminated, so the discrimination accuracy on the fiber is improved.