NCJ Number
104868
Date Published
1986
Length
52 pages
Annotation
This report describes the development of a test method to evaluate the penetration resistance of glazing materials (used as a barrier material in correctional facilities) subjected to a simultaneous attack of mechanical impact with a sharp-nosed tool and heat application.
Abstract
Glazing panels, measuring 12 x 12 in., were simultaneously subjected to repeated impacts by a pendulum with a chisel-nosed impactor and a continuous diffusion (yellow) flame delivered by propane gas torches until the chisel nose penetrated the panel. Penetration of the panel by the chisel nose resulted in a hole about 1 in, in its longest dimension. The test apparatus can be easily constructed, and it reproducibly applies mechanical impact and heat to the test panels. Sixty-three panels composed of laminated glass, glass-clad polycarbonate, or laminated polycarbonate were tested. Test results indicated a wide range in the number of impacts (1 to 116) required to penetrate the glazing. Increases in polycarbonate thickness resulted in increases in the number of impacts required for penetration. The test method was effective, and test results can be used to rank the penetration resistance of the glazing materials, provided the variability of the test results is incorporated in the ranking. 5 references and appended apparatus drawings, data results, and student's statistic values. (Author abstract modified)