ES290514A1 - Spinneret - Google Patents

Abstract

A spinneret for producing crimpable multicomponent fibres of heterogeneous cross-section comprises at least one orifice plate, and at least one orifice back plate spaced narrowly apart, each of said plates having a plurality of orifices whereby each of the orifices in the back plate is in alignment with one of the orifices in the orifice plate such that a first (core) fibre-forming component may be supplied through the orifices of the back plate to the orifices of the orifice plate, and a second (sheath) fibre-forming component may be supplied between the plates in a direction perpendicular to the supply of the first fibre-forming component. In one embodiment (Fig. 7) a core component is fed into space 10 and thence via orifices 3 in back plate 6 to the narrow space 4, 5 between the backplate and orifice plate 7. A sheath component is fed from spaces 8, 9 to flow inwardly towards the orifices so that a sheath/core multifilament is extruded through orifices 1 in orifice plate 7. The eccentricity of the core within the sheath depends upon the distance between the plates, and the diameter and density of the orifices. The orifices may be arranged in a row or rows perpendicular to the direction of flow of the second (i.e. sheath) component, and may be further arranged so that a line joining an orifice in one row to an orifice in the adjacent row is not parallel to the direction of flow of the sheath component. A preferred spinneret has 4-50 rows of orifices when the number of rows is even, or 7-51 rows or orifices when the number of rows is odd. In Example 1, a 15% solution of acrylonitrile/ methyl acrylate copolymer in 70% nitric acid at - 3 C. is extruded into 33% nitric acid at - 3 C. and the coagulated filaments are waterwashed and hot-stretched 8 times. The resulting fibres are treated with oil, dried and treated with steam at 120 C. to generate crimps.