Patent GB-1101452-A (GB)
Title: An improved spinning head for the melt spinning of conjugate filaments
IPC: D01D5/34
Filed: 1965-02-02
Abstract: 1,101,452. Apparatus for spinning conjugate filaments. ONDERZOEKINGSINSTITUUT RESEARCH. 2 Feb., 1965 [21 Feb., 1964], No. 4541/65. Heading B5B. A spinning head for melt spinning conjugate filaments consisting of two components which are bonded together along the whole length of each filament in a sheath and core configuration comprises two spinnerets which are spaced apart from one another, so as to provide an enclosed free space between the outlet face of the first spinneret and the inlet face of the second spinneret, the outlet face of the first spinneret and the inlet face of the second spinneret being opposed to one another and each spinning orifice of the first spinneret being in line with or coaxial with a corresponding orifice in the second spinneret, a means for supplying a first melt which will form the core of each filament to the inlet face of the first spinneret, and means for supplying a second melt differing in composition from the first melt (which second melt will form the sheath of each filament) to the cavity or free space between the two spinnerets, whereby the two streams enter and are extruded through each of the orifices of the second spinneret in a sheath-core relationship, with only limited intermingling of the two streams at their common boundary. The inlet duct or recess leading to the inlet end of each orifice in the second spinneret is provided with a member which projects from the inlet face of the second spinneret towards the outlet face of the first spinneret and which is non-symmetrical about the axis of the orifice the member being adjustably mounted on or attached to the second spinneret for adjustment relative to its orifice whereby the shape and/or position of the stream of the second melt entering the orifice may be varied. As illustrated in Fig. 1 the second spinneret 2 rests on the bottom ledge of a cylindrical housing 1 and the first spinneret 3 is superposed on the second spinneret 2 and is provided with an annular rim 4 which rests on the upper surface of the spinneret 2 so that inside this rim a free space 5 is left between the two spinnerets. A stream of a second spinning melt to form the sheath component of the conjugate filaments is supplied to the space 5 through the duct 6. The upper surface of the first spinneret 3 is provided with an annular recess 7 which is supplied with a stream of a first spinning melt to form the core component of the conjugate filaments, the melt being forced or extruded through a number of orifices 8 uniformly spaced in a circle into the free space 5. The second spinneret 2 is provided with a circular row of orifices 11 which are coaxial with the orifices 8. The relative position of the spinnerets 2 and 3 is fixed by means of dowels 9 so that each orifice 8 is correctly aligned with a corresponding orifice 11. The free space 5 is sealed at its periphery by a gasket 10 between the spinneret plates 2 and 3. Clamped in cylindrical recesses which constitute inlet ducts to the orifices 11 are sleeves 12 which project above the upper surface of the spinneret, the projecting portions of the sleeves being stepped or cut away as shown at 13. In a second embodiment illustrated in plan in Fig. 2, and in longitudinal section in Fig. 3, a ring 14 which varies in height is rotatably mounted on the sleeve 12 and rests on the upper surface of the spinneret 2. By turning the ring 14 around the sleeve 12 the position of the constriction in the free space 5 between the two spinnerets can be varied and the shape and/or degree of eccentricity of the core position of each conjugate filament varied correspondingly.