Method and apparatus for making two-component fibers

Abstract: In a method and apparatus for making two-component fibers, a polymer (B) which is supplied laterally with respect to a further polymer (A) and a die (12), is at first distributed inside cross-channels (23) provided in a pre-die (14), and then being redirected, through holes (16), in the extruding direction. The channels (23) operate to rearrange the polymeric mass with the new distribution above the die, so as to eliminate possible discontinuities of the values of the chemical-physical parameters of this mass and which are due to the direction variation the mass is subjected to as it is switched from the side channels (20, 22) to the cross channels (23). Thus, a constant value of the mentioned parameters through the polymer mass being supplied to the extruder is assured.

Description: BACKGROUND OF THE INVENTION The present invention relates to a method and apparatus for making two-component fibers. As is known, synthetic fibers are conventionally made by extruding through a die a molten polymeric mass. This die essentially comprises a plate provided with a plurality of very small holes, at the outlets of which a corresponding number of very thin fibers are formed. By this apparatus it is possible to also make the so-called "two-component fibers", that is yarns the construction of which derives from a combination of two different polymers. In this case, the molten polymeric masses are separately supplied to the extruding die, at the outlet of which are obtained composite construction fibers made of the two used polymers (for example the so-called "side-by-side" or "sheath-core" fibers). A critical aspect of these prior methods for making the above mentioned fibres, is constituted by the molten polymeric mass supply to the extruding die. In fact, the viscosity of the materials to be extruded, together with the very complex configuration and very small size of the channels provided for distributing the mentioned materials, will involve modifications of the design parameters related to the supply of the molten polymeric masses to the extruding die. In particular, great differences are encountered through the polymeric mass supplied to the die, with respect to the pressure, rate, temperature and viscosity values of said mass, which differences will cause in turn unevenesses in the supply of the polymers to the extruding apparatus. Because of the mentioned reasons, the amounts of extruded materials are not constant and the yarn material exiting the die has a randomly carrying count (the diameters of the fibers being very different). In particular, in making two-component fibers, the yarn is conventionally richer in the polymeric material of less density and having a smaller viscosity, and, generally, the obtained fiber includes therein the two used polymers in a randomly varying ratio. The document US-A-4 344 907 discloses a method for coextruding a first and second resin having substantially the features of the preamble of claim 1. SUMMARY OF THE INVENTION Thus, it should be apparent that in the two component fiber making field exists the need of providing an extruding apparatus suitable to provide fibers of constant count, in particular a count as near as possible to the designed count. Moreover, the need exists of assuring an even and constant distribution of the two polymers in the made two-component yarn. The aim of the present invention is just that of providing a method for making two component fibers which allows to easily make a constant or even count two component fiber having a very even and constant composition. Within the scope of the above mentioned aim, a main object of the present invention is to provide a method in which the supply of the polymeric materials to the extruding die can be accurately controlled so as to send to the extruding die even set polymeric material amounts with a set distribution (for example of the "side-by-side" and "sheath-core" type) of the polymer materials constituting the yarn being extruded. Yet another object of the present invention is to provide an apparatus for making two-component fibers of constant count and with an even distribution of the polymeric materials constituting the fiber or yarn. According to one aspect of the present invention, the above mentioned aim and objects, as well as yet other objects, which will become more apparent hereinafter, are achieved by a method for making two component fibers as claimed in Claim 1. The apparatus according to the present invention, for performing the above disclosed method is defined in claim 7. With respect to conventional prior apparatus and methods, the present invention provides the advantages of precisely controlling, point by point, the parameters (pressure, temperature, rate or speed, viscosity) affecting the supplying of molten polymeric masses to the extruding die. In fact, the polymeric mass supplied laterally to the die, and which is provided for spreading to the surface of the die, has very even temperature, pressure, values, as well as very even values of the other parameters of the polymeric mass. The mentioned discontinuities, which increase as the distance of the polymeric mass to its side supplying region is increased, are overcome or eliminated during the claimed collection and homogenizing step which is performed on the polymeric mass being laterally supplied, before sending it to the extruder. Moreover, owing to the herein claimed polymeric mass distributing system, including the above mentioned channels for distributing the components to be extruded, it is possible to precisely locally control the supplying of the polymeric materials to the extruding die. The made fiber, accordingly, will be constituted by the set composition of the set amounts of the two polymeric materials, thereby assuring an even count of the made yarn, as well as a very homogeneous composition thereof and a precise holding of its configuration or shape, for all of the fibers which are extruded. BRIEF DESCRIPTION OF THE DRAWINGS The above mentioned and other features and advantages of the present invention will become more apparent from the following detailed disclosure of a preferred, through not exclusive, embodiment of the inventive apparatus which is illustrated, by way of an indicative but not limitative example, in the figures of the accompanying drawings, where: Figure 1 is a schematic view illustrating an exemplary embodiment of a system for making two-component fibers, including the extruding apparatus according to the present invention, Figures 2 and 3 are respectively a side elevation view and a top plan view illustrating the channel arrangement for distributing the polymer A, Figures 4 and 5 are respectively a further side elevation view and a top plan view illustrating the channel arrangement for distributing the polymer B, Figure 6 is a cross-sectional view illustrating the detail 1A of the apparatus shown in Figure 1, Figure 7 is a perspective view illustrating a portion of the die shown in Figure 6, as cross-sectioned through the line of the polymer A transfer holes, Figure 8 illustrates the pre-die of Figure 7, with a cross-section taken along the line of the polymer B transfer holes, Figure 9 is a perspective view illustrating a portion of the extruding die of Figure 6, as cross-sectioned along the line of the extruding holes, Figure 10 illustrates the apparatus made by assembling the apparatus portions shown in Figures 7 and 9, and Figure 11 illustrates the apparatus as obtained by assembling the apparatus portions shown in Figures 8 and 9. DESCRIPTION OF THE PREFERRED EMBODIMENT The system for making two-component fibers illustrated in figure 1 comprises an extruding apparatus, indicated generally by the reference number 1, which is supplied with separated masses or streams of molten polymers A and B, through extruders 2 and 3 and gear pumps 4, 5. The apparatus 1 essentially comprises a distributing pack 6 and 8, with which an extruding die 10 is associated (see the detail 1A of figure 1). This distributing pack comprises: a top plate 6, of ring configuration, through the thickness of which is provided a first length 71 of the distributing channel 7 for distributing the polymer B (dashed line of figure 1), and a bottom plate 8, having a shape like that of the plate 6, and which provides the distributing channel 9 for distributing the polymer A (solid line of figure 1), as well as the second distributing channel length 74, 75 for distributing the polymer B (see the dashed lines of the detail 1A of figure 1). As is clearly shown in figures 2 and 3, the distributing channel 9 for distributing the polymer A comprises a plurality of circle arch paths 91, arranged on the plane of the annular construction of the plate 8. This duct comprises inlets 93, provided on the same plate 8, and ending with a plurality of outlet channels 92, which are arranged perpendicularly to the laying plane of the mentioned circle arches 91. The path following by the polymeric mass inside the channel 9 is such that the spacing between the inlets 93 and the outlet channels 92 is always held constant, independently from the arrangement of the outlet channels inside the plate 8 (see figure 3). Thus, the time spent by the polymeric mass from the inlets 93 to the channels 92 will be always the same, independently from the arrangement of the mentioned outlet channels 92 through the plate 8. To that end, the above mentioned channel 9 comprises a plurality of channel segments (of circle arch shape in the embodiment being illustrated) which are mutually linked with a symmetrical type of arrangement in which, at each half-circular portion of the annular plate 8 it is possible to distinguish: a first circle arch path 911, of an extension corresponding to 90°, provided for receiving the polymer A from the inlet 93 and for supplying said polymer at the level of the central or middle point of a second circle arch 912, also having an extension corresponding to 90°, the opposite end portions of which supply the polymer A to the central or middle point of respective circle arches 913. With a like arrangement, from the ends of the mentioned paths 913, like circle arch paths 914 and 915 extend, on some of which are arranged the mentioned outlet channels 92. Advantageously, in order to hold the mentioned outlet channels at a central position, or at an innermost position of the annular surface of the plate 8, the end channels 914 and 915 are included between the line of the preceding channels 912 and 913. The distributing channels 7 for distributing the polymer B, as stated, is provided with a first channel portion 71, arranged on the plate 6, which extends with two horizontal arms 72 and 73, radially oriented with respect to the annular or ring-like construction of that same plate 6 (figure 5). Each arm 72, 73 ends in turn with a respective channel 74 and 75 which is arranged perpendicularly to the arms 72, 73 and passes through the overall thicknesses of the plates 6 and 8 (see figures 4 and 5). With respect to the polymer B too, the distance of the inlets 76 on the plate 8 and all of the delivery sections or channels 74, 75 to the die, is held constant by the arrangement which has been already disclosed with reference to figure 3 (i.e. circle arch paths 711 to 715 of figure 5). With the plates 6 and 8 being combined in the distributing pack 1 of figure 1, the above disclosed channels 7 and 9 will be mutually arranged according to figure 1. From such an illustration it should be apparent the characteristic bilateral arrangement of the channels 74 and 75 for distributing the polymer B with respect to the related channel 92 for distributing the polymer A. Such a bilateral distribution will provide the channel arrangement for distributing the mentioned polymeric materials with a radial orientation with respect to the disclosed distributing pack, of the type channel 75 (polymer B) - channel 92 (polymer A) - channel 74 (polymer B). The polymers A and B, at the outlet from said distributing pack through the respective channels 74, 75 for the polymer B and 92 for the polymer A, will arrive at the spinning assembly 10 shown in figure 6. This assembly is provided with a top plate 11, having a shape like the above disclosed one, provided with a central annular chamber 13 for collecting the polymer A supplied through the channel 92. That same plate 11 is moreover provided with a plurality of side holes or channels 20 and 22 respectively arranged on the inner side and outer side of said central chamber 13 for collecting the polymer B being respectively supplied through the channels 75 and 74. Underlaying the disclosed plate 11 is provided a further plate 14, of like shape, which is adapted to operate as a pre-spinning element or pre-die. This plate, in particular, is provided with a plurality of vertically extending holes 15, which define the channel for sending the polymer A, by itself, from the mentioned chamber 13 toward the die 12. Owing to the alternated arrangement of the rows of the holes 15, the pre-die 14 will be provided with corresponding rows of holes 16, which are radially aligned with respect to the preceding holes, and allowing the polymer B to be sent, by itself, to the die 12 (arrows of figure 6). Said holes 16 communicate moreover with cross channels 23 which receive the polymer B, as bilaterally supplied with respect to the polymer A, through the channels 20 and 22 (figure 6). Under the hereinabove disclosed plate 14, is provided the die proper, which is constituted by a plate 12 in turn provided with a plurality of holes 18 arranged in the same direction of the holes 15 and 16 of the pre-die 14. In the embodiment being illustrated, each hole 18 is coaxially arranged with respect to the corresponding holes 15 of the pre-die 14. From figure 6 it should be moreover apparent that the die 12 is provided, at the ring like or annular surface engaging with the overlaying plate 14 and immediately above the holes 18, with a chamber 17. Accordingly, this chamber 17 will communicate, from the top, with the holes 15 and 16 of the pre-die 14 and, toward the bottom, with the holes 18 of the die 12. Moreover, since the axes of the mentioned holes 15, 16 and 18 are mutually parallel, the chamber 17 will transfer, in a co-current manner, the masses of the polymers A and B toward the die 12 (see the arrows of figure 6). Those same holes 15, 16, 18 can moreover have a cross section of any desired shape (either circular, square, rectangular or the like) having an area preferably from 0.03 to 3.50 mm 2 . The extruding method performed by the above disclosed apparatus according to the present invention will be disclosed in a more detailed manner hereinafter. Through the lines 21 and 31, the extruders 2 and 3 will supply the polymer A and B molten masses toward the corresponding channels 9 and 7 of the apparatus 1. More specifically, the polymer A is supplied to the spinning assembly 10 through the channels or vertical holes 92 of the plate 8, whereas the polymer B will arrive at that same assembly 10 through said vertical channels or holes 74 and 75 of the plate 6, with a bilateral distribution with respect to that of the polymer A. Thus, the polymers A and B will arrive, respectively, at the central chamber 13 and side channels 20, 22 of the plate 11 of the spinning assembly 10. From this region onward, the polymer A will flow inside the holes 15 of the pre-die 14, in a coaxial direction with respect to the direction of the holes 18 of the die 12. The polymer B, which is supplied laterally with respect to the polymer A (and, accordingly, also laterally of the die 12) will be brought above the latter, so as to be distributed inside the mentioned cross channels 23. The latter, in addition to supplying the polymer B mass from the side edges of the spinning assembly 10 toward the die 12, will operate as "plenum chambers" allowing the mentioned polymeric mass to be properly re-arranged above the die. Thus, the discontinuities of the chemical-physical parameters (temperature, pressure, speed, viscosity and so on) of the molten mass of the polymer B and which are caused by the direction change to which said mass is subjected in passing from the side channels 20, 22 to the cross channels 23, are nullified or zeroed, thereby providing an optimum constant value of these parameters, at any points inside the mass to be extruded. The polymer B mass, the parameters of which have been so adjusted in order to properly supply it to the die 12, is then oriented according to the flow streams created by the passage of said mass through the holes 16 of the pre-die 14. Thus, the polymer B which was transversely directed inside the channel 23, with respect to the extruding direction, is now caused to flow with a co-current arrangement with respect to the polymer A. Thus, the chamber 17 arranged immediately upstream of the die 12 will be always supplied by: a stream of the polymer A flowing, through the holes 15 of the pre-die 14, in the same direction as that of the axis of the holes 18 of the die 12, and a stream or current of polymer B flowing, through the holes 16 of said pre-die 14, in the same direction or in a co-current manner with respect to the polymer A flow (see the arrows in figure 8) and, accordingly, parallely to the longitudinal axis of the holes 18 of the die 12. At the inlet of the holes 18 of the extruding die 12, accordingly, will arrive the two streams of polymers A and B which were previously supplied together inside the chamber 17, in the above disclosed manner. According to a modified embodiment shown in figures 7 to 11, the pre-die 14, which is made as a single piece with the plate 11 of the apparatus of figure 6, is also provided with a plurality of holes or channels 23, each of which has a cross section which substantially corresponds to the sum of the areas of the holes 16 opening on said channel. Owing to the disclosed sizing of the holes 16 and respectively the holes 23, the polymer B (supplied to the latter holes through the hole assembly respectively indicated by 75, 20 and 74, 22) will find, inside said channels 23, a sufficient space or volume to allow the desired levelling of the pressures, before entering the chamber 17. Also in this modified embodiment, moreover, the holes 16 of each hole row radially arranged on the bottom of the pre-die 14, have diameters which can be changed depending on the melt or fluidity condition of the polymer B, thereby optimally distributing the latter in the chamber 17. Such a variation will depend, of course, on the unidirectional or bidirectional supplying of the channels 23. In the preferred embodiment shown in the mentioned figures, the number of the holes 16 corresponds to about 20% of the number of the holes 18 of the extruding die 12, and they do not have any relationship with the position or distribution of the latter. More specifically, according to a preferred embodiment of the invention, on a pre-die 14 - die 12 assembly as shown in figure 10 having a primitive diameter of 500 mm, are provided 25,000 holes 15 and respectively 18, with a diameter which can vary from 0.10 to 2.5 mm. Owing to the adoption of the size ratios which has been above disclosed, it was possible to obtain, on a system of the type "short-spin" (that is of the short-spinning type) two-component fibers having a count greater than 0.825 dtex (0.75 denier), with a very good production yield. In particular, the variation coefficient (CV%) of the count of the made fiber was less than 10. Accordingly, a high size eveness of the made fibers was obtained which confirms the great advantages provided by the present invention. In this connection it should be pointed out that the arrangement or distribution of the holes 15, 18 with respect to the holes or channels 23 can be provided in double radial rows (embodiment shown in figures 7 to 11, in which the number of the holes 23 is a half of the number of the radial rows therealong are distributed the holes 15), or also according to either individual or multiple rows (i.e. the number of the rows of holes 15 and 18 can be either decreased or increased with respect to that shown in the mentioned examples). In this modified embodiment too, the polymers or copolymers which can be used will be of commercially available types. Thus, according to the invention, the stream or current of the polymer B supplied in a cross direction above the extruding die 12 (i.e. in a direction which is different from the extruding direction) will be at first homogenized, so as to provide constant values of the parameters thereof through the overall mass thereof. Then, the polymer B will be re-addressed so as to change from a cross supplying direction to a co-current supplying direction, parallel to the extruding direction. To the achieving of a very good result on the control of the parameters of the polymers being supplied to the extruding die 12, will also contribute the configuration of the polymer distributing channels 9 and 7, for respectively distributing the polymers A and B. Such an arrangement, actually, has been designed so as to provide the polymer paths to the spinning die 10 with the same lengths, independently from the position of the corresponding delivery section 74, 75 and 92 on the distributing pack 6, 8. Thus, it will be possible to precisely and accurately control the parameters related to these components as the yarns is formed, which will accordingly have the desired count as well as the set compositions of the materials A and B, in a like manner for all of the fibers which are extruded. The embodiment of the spinning assembly 10 shown in figure 6 is of a type suitable to provide the so-called "sheath-core" yarns, in which the polymer B will completely coat a central core formed by the polymer A. In this connection it should be apparent that, by means of an offset arrangement of the holes 15 with respect to the holes 18 (not shown), it will be also possible to make yarns having a so-called "side-by-side" construction, or any other desired texture. It should be moreover pointed out that further modifications and variations can be brought to the above disclosed and illustrated apparatus, which can be related to the shape of the distributing back plates (either a quadrangular or any other shape) and with respect to the arrangement of the channels for distributing the polymers or materials to be extruded. Within the scope of the invention, the inventive apparatus can also be modified so as to include therein a single side channel (20 or 22) for supplying the polymer B to the extruding die. The cross sections of the channels 23, moreover, can also be different from the shown cross-section (i.e. outwardly tapering from the extruding die or from the center towards the edge portions of the extruding die, respectively in the case of an unidirectional or bidirectional supplying). Moreover, the holes 16 of the pre-die 14 can also be oriented differently from the above disclosed orientation and, advantageously, they could also have diameter increasing from the supply point of the component B toward the inside of the channels 23: actually, the advantages of the invention would be exclusively derived from the provision of the channels 23 for redistributing the polymer being supplied laterally of the extruding die. Finally, the above disclosed and illustrated apparatus can be used in different types of spinning systems, in particular in the "long-spinning", "short-spinning", "spun-bonding" and "melt-blown" spinning systems.

Claims: A method for making two component fibers, by simultaneously extruding molten masses of a first polymeric component (A) and a second polymeric component (B), at least one (B) of which is supplied in a direction different from the extruding direction, said method comprising, upstream of an extruding step, a step in which said second polymeric component (B) is collected and made homogeneous, so as to homogenize the values of the chemical-physical parameters of the overall mass of said second polymeric component (B) to be extruded and, downstream of said step performed on said second polymeric component (B), a step of sending said second polymeric component (B) in a separated condition from the first component (A), in the extruding direction and then the step of supplying, in a combined manner, said first and second polymeric components to said extruding step, characterized in that said first polymeric component (A) is distributed through distributing channels (9) comprising a plurality of circle arch paths (91) arranged on a first plate (8) defining a plurality of inlets (93) and a plurality of outlet channels (92) arranged perpendicularly to said circle arch paths (91), the path followed by said first polymeric component (A) in said channels (9) being such that the spacing between said inlets (93) and said outlet channels (92) is always held constant, independently from the arrangement of said outlet channels inside said plate (8), thereby the time spent by said first polymeric component (A) from said inlets (93) to said outlet channels (92) will be always the same, said distributing channels (9) comprising a plurality of channel segments which are mutually linked with a symmetrical type of arrangement, and that said second polymeric component (B) is distributed through further distributing channels (7) including a first channel portion (71) arranged on a further plate (6) having two horizontal radially oriented arms (72 and 73), each arm (72 and 73) ending with a respective channel (74, 75) which is arranged perpendicular to said arms (72, 73) and passes through the overall thicknesses of said plates (6, 8), said plates (6, 8) being overlapped to form a distributing plate pack (1). A method according to Claim 1, characterized in that said first component (A) is supplied in said extruding direction and said second component (B) is supplied unidirectionally, with respect to said component (A), to said collecting and homogenizing step. A method according to Claim 1, characterized in that said first component (A) is supplied in said extruding direction, and said second component (B) is supplied bilaterally, with respect to said component (A), to said collecting and homogenizing step. A method according to Claim 1, characterized in that said chemical-physical parameters comprise the temperature, pressure, speed and viscosity of said at least a component (B). A method according to Claim 1, characterized in that said method provides two polymeric component "side-by-side" and sheath-core" fibers, said fibers having a count greater than 0.825 dtex (0.75 denier) and with a count variation coefficient (CV%) less than 10. A method according to Claim 5, characterized in that said method is carried out by a system of the "short-spin" type. An apparatus for making two component fibers by a method according to Claim 1, of the type comprising a distributing system for distributing molten masses of a first polymeric component (A) and a second polymeric component (B), an extruding die (12) provided with holes for extruding said first and second polymeric components (A, B), in which said second polymeric component (B) is supplied in a direction different from that of said holes (18) said apparatus further comprising means for homogenizing the values of said physical parameters of said overall mass of said second polymeric component (B) to be extruded, said homogenizing means comprising distributing channels (9) for distributing said first polymeric component (A) and distributing channels (7) for distributing said second polymeric component (B), characterized in that said distributing channels comprises a plurality of circle arch paths (91) arranged on a first plate (8) defining a plurality of inlets (93) and a plurality of outlet channels (92) arranged perpendicular to said circle arch paths (91) the path followed by said first polymeric component (A) in said channels (9) being such that the spacing between said inlets (93) and said outlet channels (92) is always held constant, independently from the arrangement of said outlet channels inside said plate (8) thereby the time spent by said first polymeric component (A) from said inlets (93) to said outlet channels (92) will be always the same, said distributing channels (9) comprising a plurality of channel segments which are mutually linked with a symmetrical type of arrangement, and said distributing channels (7) for distributing said second polymeric component (B) comprising a first channel portion (71), arranged on a further plate (6) having two horizontal radially oriented arms (72, 73), each said arm (72, 73) ending with a respective channel (74, 75) which is arranged perpendicular to said arms (72, 73) and passes through the overall thickness of said plates (6, 8), said plates (6, 8) being overlapped to form a distributing plate pack, and that said homogenizing means further comprising a pre-die (14) provided with a plurality of further channels (23) arranged above said extruding die (12) in which said second polymeric component (B) is collected and homogenized in said chemical-physical parameters thereof. An apparatus according to Claim 7, characterized in that said pre-die (14) is moreover provided with a plurality of holes (16) for supplying said component (B), at the outlet of said channels (23), in the direction of said holes (18) of said extruding die (12). An apparatus according to Claims 7, 8, characterized in that each said further channel (23) has a cross-section equal to or not less than the sum of the areas of said holes (16). An apparatus according to Claims 7, 8, characterized in that the number of said holes (16) corresponds to 20% of the number of corresponding holes (18) of said extruding die (12), said holes (16) having an area not greater than that of said holes (18). An apparatus according to Claims 7, 8, characterized in that said pre-die (14) is moreover provided with a plurality of further holes (15) for supplying said first polymeric component (A) extending in the same direction of said holes (18). An apparatus according to Claim 11, characterized in that said holes (15, 16) are arranged with a mutually aligned relationship on the horizontal plane of the pre-die (14). An apparatus according to Claim 12, characterized in that said holes (15) and respectively (16) are arranged according to alternated rows on said pre-die (14). An apparatus according to Claim 11, characterized in that said apparatus comprises moreover a chamber (17), arranged between said pre-die (14) and extruding die (12), suitable to receive the co-current flows of said components (A, B) coming from said pre-die (14) so as to transfer said equicurrent flows to said extruding die (12). An apparatus according to Claim 7, characterized in that said distributing system comprises a pack of superimposed plates (6, 8) for providing a current of said second polymeric component (B) which is supplied either unidirectionally or bilaterally with respect to said first polymeric component (A). An apparatus according to Claim 15, characterized in that said distributing pack comprises a top plate (6) including a first portion (71) of a distributing channel (7) for distributing said second polymeric component (B). An apparatus according to Claim 16, characterized in that said distributing pack comprises moreover a plate (8), arranged under said plate (6) in which is formed the channel (9) for distributing said component (A), and the second distributing portion (74, 75) for distributing said component (B), with either an unidirectional or bilateral orientation with respect to said distributing channel for distributing said component (A). An apparatus according to Claim 17, characterized in that said distributing channels (7, 9) have equal length extensions, from the inlet of the respective polymers, to the outlets of said polymers to a spinning assembly (10). An apparatus according to Claim 18, characterized in that said channels (7, 8) comprise a plurality of linked channel segments which are linked with a symmetrical arrangement. An apparatus according to Claim 21, characterized in that said channels (7, 9) comprise a plurality of channel segments, arranged on the laying plane of said distributing pack, of which one (711, 911) supplies the polymeric mass to an arrangement of paths respectively (712-715) and (912-915) provided, at the end thereof, with outlet sections (74, 75; 92) for discharging said polymer to the spinning assembly (10). An apparatus according to Claim 16, characterized in that said first portion (71) of said distributing channel (7) extends with two horizontal arms (72, 73) oriented on a horizontal plane of said plate (6). An apparatus according to Claim 21, characterized in that said arms (72, 73) end with channels, respectively (74, 75) which are arranged perpendicularly to said arms (72, 73) and pass through the overall thickness of said distributing pack (6, 8). An apparatus according to Claim 17, characterized in that said apparatus has the following mutual arrangement, on a horizontal plane, of said distributing channels of distributing said components (A, B): distributing channels (75) for distributing the component (B) - distributing channels (92) for distributing the component (A) - distributing channels (74) for distributing the component (B). An apparatus according to Claim 7, for making synthetic "sheath-core" fibers, characterized in that said holes (15) of said pre-die (14) are arranged coaxially with respect to said holes (18) of said extruding die (12). An apparatus according to Claim 7, for making synthetic "sheath-core" fibers, characterized in that said holes (15) of said pre-die (14) are offset with respect to said holes (18) of said extruding die (12). An apparatus according to Claim 7, characterized in that said distributing pack (6, 8) and spinning assembly (10) have a ring-like configuration. An apparatus according to Claim 7, characterized in that said distributing pack (6, 8) and spinning assembly (10) have a quadrangular configuration. An apparatus according to Claim 9, characterized in that said holes (16) have increasing diameters which increase from the supplying point of said component (B) toward the inside of said channels (23). An apparatus according to Claim 12, characterized in that said holes (15, 16, 18) have a circular cross-section having an area from 0.030 to 3.50 mm 2 , or a differently shaped cross-section, but of equal area. An apparatus according to Claim 8, characterized in that said channels (23) have a tapering cross-section which increases from said component (B) supplying point. An apparatus according to Claim 7, characterized in that said holes (15, 18) are arranged, with respect to said channels (23), with an individual row, double row, or multiple row arrangement. An apparatus according to Claim 26, characterized in that said apparatus comprises moreover, on a pre-die (14) - extruding die (12) assembly having a primitive diameter of 500 mm, a number of 25,000 holes (15) and respectively (18). An apparatus according to Claim 32, characterized in that the diameter of said holes (15, 18) varies from 0.10 to 2.5 mm. An apparatus according to Claim 7, suitable to be used in "long-spinning", "short-spinning", "spun-spinning" and "melt-blown" systems.

Inventors: FARE ROSALDO, FARE', ROSALDO
Applicants: FARE SPA, FARE' S.P.A.
Application year: 1996
Main classification: D01D5
IPC codes: D01D5