A New Approach to the Bending Properties of Hair Fibers

In 2002, F Baltenneck and colleagues developed a new test to characterize the bending properties of treated or virgin hair fibers. The test involved a device consisting of a pendulum that bends a sample of 39 parallel hair fibers at each swinging stroke. The bending stiffness of hair could be assessed by the number of strokes observed until the pendulum stops. The study found that the mechanical behavior of natural hair fibers is related to their geometric characteristics, and the effects of various hair treatments could be assessed using this method.