Journal of Applied Polymer Science, Vol.127, No.3, 2307-2313, 2013
Periodic crazing on polymethylmethacrylate film by localized bending
Crazing was induced on a polymethylmethacrylate film using an original, low-cost, simple process in which the film was bent using a wedge-shaped plate (referred to herein as a crazing edge, or an edge). In this process, stress concentration and stress opening occur spontaneously by feeding the film past the edge, and crazing is periodically induced (periodic craze). The craze interval, width, and depth depend on the localized bending conditions at the tip of the edge. Two different types of crazing mechanism were suggested. It was assumed that the films were either crazed by bending along the tip of the edge or by bending according to the curvature induced by the three-point bending system. The calculated maximum stress determined by the three-point bending process and the experimental values of the craze interval and width showed similar tendencies. These results suggested that the craze depth could be determined using this bending process and known mechanical properties and crazing conditions. (c) 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013