Abstract: Method and Apparatus for forming an elastomeric strip formed from at least two elastomeric compounds, for example to use as a pneumatic tire tread strip. Extrusion means advance two or more elastomeric materials (60) under pressure toward a final die chamber; from which material is extruded between a final die (50) and a roller (70). A head assembly (30) and a preform die (62, 64) are positioned in serial flow relationship between said extrusion means and said final die, and flow chambers formed within said head assembly and said preform die intercommunicate said extrusion means with said final chamber. Flow chambers within the preform die converge to at least one common junction within said preform die to form a single preform die exit chamber wherein a multi-material flow of elastomeric materials is established for passage into said final chamber for final extrusion therefrom.

Abstract: In extrusion apparatus of the type having a generally cylindrical roller, a stationary die head surface confronting the roller and defining therewith an extrudate chamber, and means for rotating the roller to force material through the chamber to an extrudate shaping orifice defined by the roller and a downstream portion of the die head, a bearing pad is interposed between the roller and the die head. The roller is biased against the bearing pad so that the pad serves to space the roller from the die head to accurately control clearance between the die head and roller at the extrudate shaping orifice.