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High Speed Fiber Testing: The Single Fold Test



Haruki Kobayashi, Walter G. McDonough, Alexander J. Shapiro, Jae H. Kim, Stefan D. Leigh, Amanda L. Forster, Kirk D. Rice, Gale A. Holmes


The failure of a first responder s body armor has prompted research to assess the long-term durability and effectiveness of current and future soft body armor products. Prior work in this laboratory described a 10 % drop in tensile strength and 15 % drop-off in modulus in poly(p-phenylene benzobisoxazole) (PBO) fibers after they were subjected to a single fold for 24 h. In addition, regions of internal damage were seen in the folded fibers. Here, that work was continued by investigating the response of poly(p-phenylene terephthalamide) (PPT) fibers to the same condition. The results presented in this paper show no change in tensile strength, modulus, or failure strain in the PPT fibers and a different surface morphology in the folded region. Furthermore, results show a continued drop-off in the mechanical properties of PBO fibers that is possibly due to hydrolytic degradation.
Proceedings Title
SAMPE 2010 Annual Technical Conference
Conference Dates
May 17-20, 2010
Conference Location
Seattle, WA, US


ballistic fiber, PPT, single fiber test


Kobayashi, H. , McDonough, W. , Shapiro, A. , Kim, J. , Leigh, S. , Forster, A. , Rice, K. and Holmes, G. (2010), High Speed Fiber Testing: The Single Fold Test, SAMPE 2010 Annual Technical Conference, Seattle, WA, US, [online], (Accessed April 20, 2024)
Created May 19, 2010, Updated October 12, 2021