Patent GB-579081-A (GB)
Title: Apparatus for the production of composite artificial filaments
IPC: D01D5/32
Filed: 1944-02-29
Abstract: <PICT:0579081/IV/1> <PICT:0579081/IV/2> <PICT:0579081/IV/3> <PICT:0579081/IV/4> <PICT:0579081/IV/5> <PICT:0579081/IV/6> <PICT:0579081/IV/7> Composite artificial filaments are obtained by extruding two or more filament-forming materials of different properties, in a fused or plasticised state or in the form of solutions thereof, in separate or only partially intermingled phases through a common orifice or a plurality thereof where they are joined together in eccentric or side by side relation, into a gaseous or liquid setting medium which may function by either a cooling, precipitating or evaporative effect.  Any filament-forming materials or solutions differing in composition origin or characteristics such as differing solutions of viscose, proteins such as casein or soya been protein, cellulose derivatives such as cellulose acetate or ethyl cellulose, and resins such as nylon, vinyl resins such as the copolymers of vinyl chloride and vinyl acetate and the vinylidene halides, may be employed. Alternatively, two or more materials of different classes may be combined such as a protein with a viscose, a protein with a cellulose acetate or a cellulose acetate with a vinyl resin.  The composite filaments are spun from a spinneret which comprises a filament-forming orifice plate and a septum or series of septa dividing the space behind the orifice plate into a plurality of substantially separate regions communicating with each other in the vicinity of the orifices.  Referring to Fig. 1, differing spinning solutions are fed by pipes 6 and 7 and passageways 14 and 15 to the chambers 12 and 13 behind the spinneret face 1.  A septum 11 separates the chambers 12, 13 and its sharpened lower edge bisects the orifices 2 in the spinneret face, so that the different spinning materials are united at the orifices 2 and emerge in the form of composite filaments.  The lower edge of the septum may be slightly set back or offset from the orifices 2. Any number of different components may be fed to the spinneret by employing a complex or branch septum system as shown, for example, in Fig. 3d, the different materials being separated by septa 21 and united at and extruded through orifices 22.  A mixture of filaments, some composite and some of a single spinning material, may be spun simultaneously from the one spinneret by providing additional orifices under each chamber 12 and 13 (Fig. 1), and to one side of the diametrial row of orifices 2, and the denier of the filaments, composite and/or otherwise, may also be varied by employing orifices of differing diameter.  In a modification (Fig. 4), a plurality of holes 42 spaced apart in parallel rows extend across the spinneret face 41.  Different spinning solutions are fed through passageways 57, 58 in distributing member 50 to alternate regions formed between septa 56 (Fig. 6) from which they pass together through orifices 42.  In another modification (Fig. 7), the spinneret holes 62 are arranged radially. A distributer 75 is provided with an annular series of passages 77 through which one spinning material is passed, alternating with a series of passages 78 through which another spinning material is passed.  The space 80 behind the spinneret face is divided into regions by a plurality of radially extending septa 79 positioned in alignment with the orifices 62.  Different spinning materials are fed to alternate regions between septa 79 from which they pass together through holes 62.  In a further modification (Fig. 10), the spinneret face is provided with a plurality of orifices 92 spaced apart in concentric rings. Different spinning materials pass through passages 107, 108 to alternate regions formed by the annular concentric septa 106.  The materials then pass through holes 109 in plate 101 and form alternate rings of different material in the space behind the spinneret face from which they pass together through orifices 92. In another modification (Fig. 13), different spinning materials are passed through passageways 134, 135 in distributer 129 to alternate regions separated by annular septa 133.  The materials then pass through passages 138 in the feeder 136 and form alternate rings in the regions separated by annular septa 137, from which they pass together through orifices 121.  The cross-sectional proportion of the several components of the filament may be varied by feeding the materials to the spinneret through constant volume pumps with adjustable outputs, or by varying the size of the feed passages. Crimped filaments may be obtained by stretching the composite filaments during production and allowing them to relax or stretching them subsequently to production and softening them, by e.g. wetting, in the relaxed condition.  When stretching is effected subsequently to production, it is preferably carried to such an extent that at least one and preferably all the filament components are stretched beyond their elastic limit.