Patent GB-954274-A (GB)
Title: Apparatus for spinning crimped artificial filaments
IPC: D01D5/32
Filed: 1962-07-13
Abstract: 954,274. Apparatus for spinning crimped composite artificial fibres. JAPAN EXLAN CO. Ltd. July 13, 1962 [July 14, 1961], No. 26992/62. Heading B5B. In the spinning of a crimped composite fibre by extruding two or more different spinning solutions or melts concurrently through a common orifice into a coagulating, evaporating or cooling medium, the solutions or melts are caused to flow separately as thin confined films moving in laminar flow towards a juncture thereof, then caused to flow from such juncture toward the orifice as two or more thin films moving in laminar flow with their adjacent faces in non-mixing interfacial contact, and the solutions or melts are then extruded through the orifice. A slight turbulence may be imparted to at least the interfacial regions of the films as the spinning solutions or melts enter the orifices whereby the solutions or melts are slightly intermixed at their interfacial regions. As shown in Figs. 1 to 6, a spinning jet for producing crimped bi-component fibres comprises a spinneret plate 11, a guide plate 13 (Figs. 1 and 6), and a cylindrical insert member 15 (Figs. 1 and 3) supported in a spinneret holder comprising a cap 17 and nut 18 on the end of a supply tube 19. Spinneret plate 11 is provided with a number of orifices 21 (Fig. 6) arranged in rows which are spaced from each other. The orifices 21 in any single row are spaced apart a distance equal to the inside diameter of the orifice inlet at the rear face of the spinneret plate (Fig. 5). The guide plate 13 is provided with a number of channels 23 having a Y-shaped transverse section (Figs. 1 and 6). The width of the base of each channel is equal to the diameter of the inlets of the orifices 21 and the length of the channel in the dimension parallel to the spinneret plate 11 is equal to the length of the row of orifices 21 with which it communicates. The inlet section of the member 15 is divided by a baffle 25 (Figs. 2 and 3) into two chambers 26 and 27 and the outlet section is provided with two groups of slots 29 and 30 (Fig. 1). Each of the slots 29 is provided with a duct 32 (Fig. 3) communicating with the chamber 26 and is isolated from chamber 27, whereas each of the slots 30 is provided with a duct 33 (Figs. 1 and 3) communicating with chamber 27 and is isolated from chamber 26. The plates of member 15 that separate slots 29 and 30 from each other terminate in V-shaped edges which, when member 15 is in position abutting on guideplate 13 (Fig. 1), coact with the upper portions of Y-shaped channels 23 in guide plate 13 to provide narrow V-shaped channels 35 (Figs. 4 and 6). A different spinning solution or melt is introduced into each of the chambers 26 and 27 from separate supply sources, not shown and discharges into a common narrow channel 36 of slot-shaped cross-section which is at the base of the Y-shape channel 23, through which the two solutions or melts flow as a pair of contiguous films moving as a single two-ply film unit in laminar flow. By suitable adjustment of the relative rates of flow of the two solutions or melts the interface between the two films flowing down ducts 36 can be centred over the row of orifices 21. A fine mesh screen, preferably having 115 to 350 meshes to the inch is interposed between spinneret plate 11 and guide plate 13 to impart a slight turbulence to at least the interfacial regions of the two spinning solutions or melts flowing in laminar flow to produce a slight intermixing of the solutions or melts at their interfacial regions. Any tendency for separation of the two components of the resulting bicomponent fibres is thereby minimized if the components have different shrinkage characteristics. By appropriate modifications of the apparatus crimped fibres consisting of more than two components may be spun.