The superior ballistic performance of highly stretchable and flexible double-face knitted fabrics(DFKF): An experimental investigation

When the protective and protected systems are detached, the former can be allowed to absorb the kinetic energy of the impacting projectile through large deformation without considering the back face signature of the latter. This paper presents a novel double-face knitted fabric（DFKF） designed for this very impacting scenario. Shooting tests equipped with high-speed camera were used to characterize the ballistic performance with the impact velocities ranging from 100 m/s to 450 m/s. The results showed that the ballistic limits(Vbl) of DFKF are approximately triple and double that of its counterpart UD and plain fabrics, respectively. For mass-normalized metrics, the specific energy absorption（SEA） is 250% and 350% greater than the UD and plain fabrics at their corresponding Vbls. The quasi-static tests showed that the DFKF displayed greater resilience, crease recovery properties, and flexibility, which also made it an especially better candidate than UD and plain weaves for the design of umbrella surface cloth. It was also found that DFKF is dependent on yarn count and the incorporation of spandex. A prototype anti-ballistic umbrella is manufactured using DFKF made of 200D multi-filament yarn. The ballistic performance is also sensitive to the impact site when the umbrella is subjected to impact.