an apparatus and method for continuously producing a sheet composed of a plurality of materials co - extruded in segments along the width of the sheet are provided . the extrusion die has a slit extending along the width of the die , the slit being divided into a plurality of adjacent sections along the length of the slit . the widths of each of the segments are variable and can be accurately controlled . feeding means for feeding material to each of the separate adjacent sections is provided . the method and apparatus are effective to produce a thermoplastic sheet having two or more layers in a central portion of the sheet and only a single layer at the edge portions of the sheet .