| abstract |
A protective, impact resistant material and method, the material comprising a fabric of thermoplastic polymeric fibers having a strength of at least 0.5 GPa and an elastic modulus of at least 25 GPa and a matrix of polymeric material disposed in the interstices between the fibers, the matrix having an elastic modulus in the range 0.2 to 3×10 6 psi. The polymeric fibers can be gel spun polyethylene, polypropylene, nylon, polyvinyl alcohol and polyethylene terephthalate. In a second embodiment, the matrix is derived from the fabric. The method of making the material comprises providing a matrix of melted polymeric material transparent to energy of a predetermined type and having a predetermined melting temperature, placing a fabric of polymeric fibers having a melting temperature higher than the melting temperature of the matrix in the matrix, applying a pressure of 1000 to 2000 psi to the fabric disposed in the matrix, then raising the temperature to the melting temperature of the fabric for the minimum time required to cause consolidation of the fabric and the matrix and rapidly cooling the consolidated fabric and matrix to a temperature below the melting temperature of the fabric. In accordance with a second embodiment there is provided a fabric of polymeric fibers as in the first embodiment which is operated upon as in the first embodiment to cause melting of a sufficient portion of the fabric to fill the interstices between the fibers of the fabric and the fabric is then rapidly cooled to a temperature below the melting temperature of the fabric. |