Extrusion apparatus, process and article

Abstract

A unitary extruded thermoplastic article that may be a concrete joint former having an intermediate tear plane formed from an admixture of a plasticizer or a filler in the amount of 150 to 1500 parts per 100 parts of thermoplastic resin. A process for producing an extruded article having a strippable top and a lower tear strength intermediate portion including extruding one thermoplastic material into separate spaced strips, extruding another thermoplastic material into the space between the strips and then compressing the strips to form a unitary article. An extrusion die apparatus for extruding at least two different thermoplastic compositions. A distributing means including a separating means for dividing the thermoplastic flow within the passageway and dispensing a second composition into the divided flow. A method for reducing the tear strength of a thermoplastic material while retaining adequate tensile strength by incorporating a filler or plasticizer in amounts greater than 150 parts per 100 parts of the thermoplastic.

Dependencies are inferred from the claim text.