Specialty Materials, Inc.
HY-BOR® FIBER COUNT AND COMPRESSION STRENGTH
Since the early 1990’s there has been a significant amount of compression test method development for high strength advanced polymer matrix composite materials. Most of this work has focused on the use of cross-plied laminates to derive equivalent 0o lamina compression strength and modulus. In 1995, Dr. John Gillespie of the University of Delaware’s Center for Composite Materials reported on the “Influence of Boron Fiber Count on Compressive and Shear Properties of Hy-Bor”. His study was conducted using 16-ply [0/90]4s laminates of Boron/IM7/Epoxy Hy-Bor and the IITRI compression test method.
For this study five variations in the number of boron fibers per inch (fpi) in the Hy-Bor prepreg were produced and tested to determine the effects of percent boron fiber on compressive strength, modulus and % strain to failure. This study shows that beneficial improvements in compressive strength and modulus can be obtained at boron fiber additions between 100 fpi and 200 fpi. In part due to these results and in part due to manufacturing constraints, standard Hy-Bor® product offerings of 208 boron fpi and 100 boron fpi were established. Click below for the full pdf version of this paper.
Hy-Bor Fiber Count and Compression Strength
A more recent study by Dr. Alan Nettles of Stanford University has demonstrated that compression strength after impact (CAI) for IM7 Gr/Ep composites is significantly improved by adding either Hy-Bor® 100 or Hy-Bor® 208 to quasi-isotropic laminates