Evaluation of recycled Al–LDPE–Al sandwich panels as ballistic protection material Available to Purchase

Metal–polymer–metal hybrid sandwich panels are gaining importance in civil, automotive and aerospace applications due to their light weight and damping properties. Compared with composite materials, hybrid materials consisting of separate metal and thermoplastic parts can be recycled much more easily. Besides their applications as covering material on buildings as well as general insulation material, recycled aluminum (Al)–low-density polyethylene (LDPE)–aluminum hybrid panels yield a potential usage of light ballistic protection. In this study, a standard hybrid panel of 3·2 mm polyethylene filling and two 0·4 mm aluminum metal sheets was experimentally tested under ballistic impact. A finite-element model was used with a commercial software program and validated against the experimental results. The finite-element results show that stacking of multiple layers of panels absorbs more energy than an equivalent single-layer panel. Six layers of stacked hybrid aluminum–LDPE–aluminum panels are capable of absorbing the impact energy of a 9 mm pistol projectile, and they can be utilized as recyclable inexpensive ballistic protection materials.