Extrusion process using a central air jet

Abstract

A thermoplastic material extrusion mechanism is provided which includes a die head having a centrally disposed high velocity gas delivery means adapted to continuously emit a jet of a gas having shear layers, at least one chamber for the thermoplastic material, thermoplastic material delivery means arranged at least partially surrounding the centrally disposed high velocity gas delivery means for directing extruded thermoplastic material emitted from the thermoplastic material delivery means toward the gas jet, causing the extruded thermoplastic material to be introduced into the shear layers of the gas jet, and a thermoplastic material conduit which communicates the at least one chamber with each of the thermoplastic material extrusion openings. A method of producing fibers of a thermoplastic material is also provided which comprises the steps of (a) forming a high velocity gas jet having shear layers, (b) extruding at least one stream of a molten thermoplastic material from at least one thermoplastic material delivery means arranged adjacent and at least partly surrounding the high velocity gas jet, and (c) merging the at least one thermoplastic material stream with the shear layers of the high velocity gas jet to attentuate the thermoplastic material into fibers, forming thereby fiber streams of the thermoplastic material.

Dependencies are inferred from the claim text.