Patent GB-1215315-A (GB)
Title: An apparatus for the spinning of composite synthetic filaments
IPC: D01D5/30
Filed: 1967-11-22
Abstract: 1,215,315. Spinneret for composite filaments. ALGEMENE KUNSTZIJDE UNIE N.V. 22 Nov., 1967 [23 Nov., 1966], No. 53207/67. Heading B5B. An apparatus for the spinning of composite synthetic filaments comprises a feed system for each of the polymers to be spun and a spinning assembly housing connected thereto, which assembly housing has at least one substantially horizontal spinneret plate with orifices arranged in a pattern and a closable mounting and dismounting hole and sealing means therefor, in which the horizontal section of the assembly housing is oblong, by preference substantially rectangular, and has a length which is at least one and a half times the width, and in which the likewise oblong perimeter of the spinneret plate which is placed in the assembly housing has in the horizontal plane dimensions which are less than but of the same order of magnitude as those of the assembly housing, said horizontal dimensions of the spinneret preferably amounting to at least 75% of the corresponding internal dimensions of the housing. The term composite is defined as embracing both conventional filaments made from polymer blends, and conjugate filaments of both the "side-by-side" and "sheath-core" types. In the three forms of apparatus shown, that of Figs. 1 to 4 (Figs. 2 and 3, not shown) is suitable for the production of composite filaments of conventional form made from two polymers, the polymers being intimately mixed in the spinning assembly housing, that of Figs. 5, 6, and 7 (Figs. 6 and 7, not shown) is a spinning assembly for the manufacture of conjugate filaments of the "side-by-side" type, and Figs. 9, 10 and 11 (Figs. 10 and 11, not shown) show the construction of a third spinning assembly, for the manufacture of conjugate filaments of the "sheath-core" type. In these two latter types the mixer unit of the apparatus of Figs. 1-3 is replaced by a distributer unit suitable for the production of conjugate filaments. Thus in Figs. 1 to 3 an apparatus suitable for the production of composite filaments comprises an assembly housing 1 and a spinneret plate 2 having a rectangular cross-section in a horizontal plane. The spinneret plate 2 has a large number of spinning orifices 3 arranged in a pattern, the outer boundary of which is also rectangular. In a space over the spinneret plate 2 is a filter gauze pack 6. In each of the short sides of the housing 1 there is a closable mounting and dismounting hole 7, the height of which is referred to by 8 and the width by (9), Fig. 3, not shown. On the spinneret plate 2 rests a mixer which consists of a lower block 10 and an upper block 12 secured thereto with bolts 11. The openings 7 are closed on the outside by sliding covers 13. The dimensions of the spinneret plate 2 in the horizontal plane are of the same order of magnitude as those of the interior of the assembly housing 1. In housing 1 there are two feedlines 19 and 20, from which each of the polymers can flow downwards via respective filter gauze packs 21 and 22 and respective distribution plates 23 and 24. Plates 23 and 24 each rest on the upper side of the upper block 12 of the mixer. The distribution plates have a large number of perforations 27, and under plates 23 and 24 there are, in the upper block 12 of the mixer, funnel-shaped collecting chambers 28 and 29, which at their bottom ends communicate with horizontal channels 30 and 31. In channels 30 and 31 the two polymers can flow towards each other in the direction indicated by the arrows 32 and 33, respectively. When the two polymers have met they can flow collectively in the direction indicated by the arrow (34) through the channel (35) to the beginning of a mixing channel indicated by 36, which mixing channel has a square cross-section (Figs. 2 and 3, not shown). Mixing channel (36) follows an approximately rectangular path (Fig. 3) and is partially filled with guiding members (37), indicated in Fig. 3, by a cross. The two polymers can flow through the mixing channel (35) in the directions indicated by the successive arrows (38) to (45), and as a result of the mixing action of the guiding members the number of layers of the two polymers are repeatedly doubled so that the materials are finely intermixed. Figs. 4a-4e show an embodiment of the combination of stationary guiding members having a satisfactory mixing action. Fig. 4a shows the end face of the combination of a guiding members, this combination consisting in principle of a bar having a square cross-section and recesses in its side walls. In Fig. 4a the arrows b, c, d and e, indicate the directions in which the side elevations shown by the Figs. 4b, 4c, 4d and 4e are viewed. The path of the molten spinning material through the grooves is shown by the lines 46 to 49. In the mixing channel 36 a suitable number of guiding members may be provided. In Fig. 3, numeral (50) refers to the end of the rectangular mixing channel (36). From the end (50) the mixed polymer can flow downwards through an inclined channel (51), in the direction indicated by arrow (52), (Fig. 2, not shown), after which the polymer can distribute itself over the filter gauze pack 6 and can leave the spinning assembly through the spinneret plate 2 having orifices 3. On the housing 1 are ears 53 and 54 by means of which the housing can be placed in a heated jacket (not shown) or removed therefrom. Plugs 55 and 56 in housing 1, over the centre of the distribution plates 23 and 24 may be removed for the purpose of withdrawing the distribution plates and filter gauze packs. In the apparatus of Fig. 1, the dimensions of the openings 7 are such that the mixer formed by the lower block 10 and upper block 12 can be removed from or placed back into the assembly housing through one of said openings 7. Similarly the other parts present in housing 1, e.g. the spinneret plate 2 with filter gauze pack 6, and the distribution plates 23 and 24 with respective filter gauze packs 21 and 22 can be withdrawn or replaced through the relatively small openings 7 in the short side walls of housing 1. Consequently, the relatively large assembly can simply be given a rigid construction. Figs. 5 to 7, 9, 10 and 11 (Figs. 6 and 7, 10 and 11, not shown) are sectional views of two conjugate-spinning assemblies in which no mixers are present, like parts shown in Figs. 1, 2 and 3 being referred to by like numerals. Figs. 6 and 7 (not shown) are sectional views along the respective lines VI-VI and VII-VII in Fig. 5 and Figs. 10 and 11 (not shown) are sectional views along the lines X-X and XI-XI in Fig. 9. In the assembly shown in Fig. 5, as well as in that of Fig. 9, the two polymer components then flow down from the funnel-shaped collecting chambers 28 and 29 to approximately the level of the upper side of the spinneret plate 2 through entirely separated systems of feed channels (58) and (59) for the right hand polymer component and (60) to (64) for the left hand component. Feed channels (58) to (64) for the two components are located in three feed plates (65), (66) and (67) positioned one above the other (Figs. 6 and 10, not shown), and over the spinneret plate 2, which feed plates are further so positioned in the assembly housing 1 that they are opposite the closable mounting and dismounting hole 7 in the short side of the assembly housing 1. Feed channels (59), for the one polymer fed to the right hand upper side of the assembly, extend downwards near the outer perimeter of the plates (65, (66) and (67), and feed channels (61) to (64) for the other polymer component extend downwardly within the space defined by channels (59). The spinning assembly according to Figs. 5, 6 and 7 is meant for the manufacture of conjugate filaments of the "side-by-side" type. Each of the vertical feed channels 63 in the lowermost plate 67 discharges over two adjacent spinning orifices 3 in the spinneret plate 2 (see Fig. 5). The polymer, which can be supplied through the vertical channels (59), is distributed horizontally over the spinneret plate 2 by a large number of obliquely place horizontal channels which extend across the lower side of the plate 67 and each of which covers at least two adjacent spinning orifices 3. With such an embodiment the two polymer components each practically fill one half of each spinning orifice 3, as a result of which filaments of the "side-by-side" type are formed. The assembly in Figs. 9 to 11, is meant for the manufacture of conjugate filaments of the "sheath-core" type, and in this embodiment each of the vertical feed channels (64), Fig. 10, not shown, in the lowermost feed plate 67 has a narrow outflow opening which ends over the centre of a single corresponding spinning orifice 3. The polymer component which has flowed downwardly through the vertical channels (59), (Fig. 10, not shown) can distribute itself over the upper surface of spinneret plate 2 through recesses in said surface and can then flow to spinning orifices 3 at the outer circumference thereof. With such a construction of the spinning assembly the one polymer component forms a core, and the other the sheath surrounding the core. Figs. 13 and 14 (not shown) show diagrammatically how the assembly of Figs. 9 to 11 can, by a small modification, be rendered suitable for the manufacture of conjugate filaments of the "side-by-side" type. In this embodiment the feed channels (64) discharge eccentrically over the spinning orifices 3. In this construction, the spinning orifices are partly covered, at their upper sides, by the outlets of the feed channels for the other component.