Abstract: An elongated flat die, for extruding parallel streams of different polymers to form a continuous, striped film, includes a body member which houses a replaceable insert. The insert is formed with grooves on at least two abutting surfaces, which, together with the interior surfaces of the body member, define separate, alternating passages through which the polymers flow. Streams of the different polymers flow together in alternating arrangement and exit the die through a variable lip passage.

Abstract: Film extrusion-fibrillation and film extrusion-narrow slitting processes for preparing fibrillated or narrow-width thermoplastic tape. The process is characterized by conducting the extrusion-orientation stage and the slitting or fibrillation stage as separate operations, thereby minimizing process disruptions caused by film defects and breakage, and further characterized by certain film shrinkage and heat treatment modifications which facilitate such separate stage operation. The fibrillated tapes can be twisted into cordage products. The narrow-width tapes are used to make carpet backing and indoor-outdoor carpet.