GB749750A - Improvements in and relating to spinnerets - Google Patents

Abstract

A spinneret suitable for the extrusion of nylon and similar melt-spun materials comprises a relatively thick body portion or disc having therein a number of holes or bores of relatively large diameter uniformly tapered throughout their length towards the spinneret face, and a non-precious metal insert member having therein a single preformed extrusion orifice located in each of the holes or bores, the insert member being correspondingly externally uniformly tapered so as to engage tightly with a force fit within its bore and be retained therein without mechanical or other securing means. The extrusion orifice comprises a tapered inlet portion and a cylindrical parallel-sided capillary outlet portion of reduced diameter joined at its upper end to the lower end of the inlet portion through the intermediary of a tapered portion, the angle of conicity of which is greater than that of the inlet portion. The length of the insert members is equal to the thickness of the body portion or disc and they are so located in their holes that their upper and lower surfaces are flush with the upper and lower surfaces respectively of the body portion or disc. Should one or more of the extrusion orifices become clogged or damaged in use, it is not necessary to replace the entire spinneret, but only to force out of the body portion or disc the affected insert member or members and to fit a new insert member or members into position. The spinneret body portion or disc and the replaceable insert members may be made of any suitable non-precious metal, such as stainless steel, chromium-steel alloy, or nickel alloys such as nickel-iron alloys. The spinneret may consist solely of a relatively thick disc provided with extrusion orifices as above or may be in the form of a cup of which the bottom wall constitutes the perforated disc.