The R&D team of Protech published a paper online titled "Bulletproof properties and failure mechanism of para-aromatic polyamide fiber/epoxy resin composite" online in the Chinese core journal Acta Materiae Compositae Sinica on December 21st, 2018. 

In order to investigate the bulletproof performance and failure mechanism of Para-aromatic polyamide fiber/epoxy resin composite, the lead core projectiles were employed to penetrate composite target. The type of reinforcement was Para-aromatic polyamide fiber, whereas the resin was Epoxy resin (EP); Nano-SiO2 and Polyvinyl butyral (PVB) were worked as modifier. Unidirectional (UD) composites were fabricated using hot pressing process. The effects of single-layer fiber areal density, the structure of UD sheet, shooting angle and resin modification on ballistic properties were discussed. Also, the final fracture morphologies were observed by the stereomicroscopy. More importantly, the failure mechanisms of composite target subjected to the ballistic impact were analyzed. The results showed that Para-aromatic polyamide fiber/epoxy composite exhibit excellent bulletproof performance. As the increasing of single-layer fiber areal density, the bulletproof performance of composite increases with fluctuations. Moreover, the bulletproof performances of 4UD structures are superior to those of 2UD structures. When shooting with an angle, the higher penetration layer ratio and smaller back face signature (BFS) ratio are found. Also, PVB improves the bulletproof performance. Furthermore, it can be concluded that the energy absorptions are influenced significantly by the tensile deformation of fiber, the delamination of sheet and the matrix resin cracking.