Patent ID: 8252216

Claim:
A method for manufacturing a railway tie having a first portion fabricated of a first composition and a second portion fabricated of a second, different composition, said first composition comprising 15% to 75% by weight of a first asphaltic component and from 85% to 25% of a first polymeric composition and said second composition comprising from 20% to 85% by weight of a second asphaltic component and from 80% to 15% by weight of a second polymeric component, each of said first and second polymeric component comprising a mixture of a recyclable plastic and a strengthening agent, comprising the steps of: (i) separately preparing and blending selected amounts of asphalt and plastic to produce a first blend having said first composition and a second blend having said second composition; (ii) separately melting and processing said first blend and said second blend in processors operable to heat and feed said blends separately as composite asphalt plastic composition to pump means associated with a co-extrusion die; and (a) pumping the heated and semi-fluid first composition into a first section of a mold to form said core portion of the railway tie, and simultaneously injecting the heated and semi-fluid second composition into an outer portion of the mold to form the outer portion of said railway tie, or (b) pumping the heated and semi-fluid second composition into a first section of a mold to form said core portion of the railway tie, and simultaneously injecting the heated and semi-fluid first composition into an outer portion of the mold to form the outer portion of said railway tie.