Protection against impacts and perforation is ensured by a shell in carbon fibers and aramid, and by an expanded polystyrene inner padding with high density.

The free volume properties of high impact polystyrene (HIPS)-low density polyethylene (LDPE) blend have been investigated by means of positron annihilation lifetime spectra (PALS).

In the near-fields, the gas-phase turbulence intensities are augmented more by glass particles with larger density than polyethylene particles with smaller density.