Fragment ballistic performance of homogenous and hybrid thermoplastic composites

• We investigated the ballistic efficiency of Twaron®/Dyneema® hybrid composites.
• We used low-density polyethylene as the matrix of hot pressed hybrid composites.
• Thinner fibers and greater pull-out force of threads led to higher efficiency.
• High dense aramid fabrics on the strike face seems to give promising hybrid.
• Ballistic limits of hybrids are about the same in the temperature range −60 … +60 °C.

Extensive ballistic tests have been carried out on various protective composites structures up to 900 m/s speed and at elevated and sub-zero temperatures using 6.35 mm steel ball. The ballistic performance was assessed in terms V50 threshold as well as post V50 limit. Multi-layered aramid fabric (Twaron®, RUSLAN®-SVM)/LDPE matrix composite laminates were compared with multi-layered UHMWPE systems based on Dyneema® (HB2, HB80) and with hybrid aramid/Dyneema® HB2, Dyneema® HB2/Dyneema® HB80 laminates. The effect of temperature was observed to be negligible, although brittle behavior resulted in a wide scatter at −60 °C. Laminates based on UHMWPE fibers are much better than others in respect to the values of on indicators of V50 (about 10%) and of the absorbed energy (about 25%) under high-velocity impact conditions. But their energy absorption capability can sharply drop down when projectile's velocity exceeds the ballistic limit.