Desenvolvimento de compósito reforçado com tecido artesanal e reaproveitamento de colete balístico

Abstract

This study evaluated the response in ballistics tests of polyester composites reinforced with unidirectional non-woven fabric (TNT) obtained by dismantling ballistic vests, fabric with a commercial plain weave structure, and handmade fabrics with a twill weave structure, all reinforced with para-aramid. The ballistics tests were conducted based on NIJ Standard 0108.01 using .38 caliber hollow point ammunition. The ballistic plates were molded using the compression molding method in a closed steel mold with different staking sequences. The influence of the composition on the ballistic resist performance was evaluated by analyzing the level of damage by optical microscopy of the composites produced and the deformation profile of the projectiles after impact. He observed that the coverage factor of the fabrics used was a relevant parameter in the interpretation of the results. Another factor of great importance is related to the projectile's frontal profile, where the damage propagates in the direction of the fabric structure that reinforces the composite. The results suggest that the fabric with a plain weave structure is not interesting for use as a reinforcing element for ballistic composites. In this case, the structure did not act satisfactorily in absorbing and dissipating the energy of the projectile impact, resulting in perforations with a high level of damage in the sample, and the deformation in the diameter of the projectile significantly lower than that of the plasticine. The fabric-reinforced composite with a specific handmade twill structure was effective in absorbing the impact of the projectile, despite the low reinforcement content (27.3%), and this behavior was attributed to the fabric's coverage factor. For the composites reinforced with unidirectional TNT, the results showed the feasibility of using this material to make composites for ballistic protection. The hybridization of the reinforcements, i.e., the combination of reinforcements with a twill structure and unidirectional TNT, was effective and showed excellent ballistic performance, without perforating, encapsulating, and fragmenting the projectile inside the plate.